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, pointonplanes, pointswithinsufficientplanes, 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                 pointswithinsufficientplanes = 0;
 351                 for (k = 0;k < brush->numplanes;k++)
 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                         pointonplanes = 0;
 357                         for (k = 0;k < brush->numplanes;k++)
 358                         {
 359                                 d = DotProduct(brush->points[j].v, brush->planes[k].normal) - brush->planes[k].dist;
 360                                 if (d > (1.0f / 8.0f))
 361                                 {
 362                                         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);
 363                                         printbrush = true;
 364                                 }
 365                                 if (fabs(d) > 0.125f)
 366                                         pointsoffplanes++;
 367                                 else
 368                                         pointonplanes++;
 369                         }
 370                         if (pointonplanes < 3)
 371                                 pointswithinsufficientplanes++;
 372                 }
 373                 if (pointswithinsufficientplanes)
 374                 {
 375                         Con_Print("Collision_ValidateBrush: some points have insufficient planes, every point must be on at least 3 planes to form a corner.\n");
 376                         printbrush = true;
 377                 }
 378                 if (pointsoffplanes == 0) // all points are on all planes
 379                 {
 380                         Con_Print("Collision_ValidateBrush: all points lie on all planes (degenerate, no brush volume!)\n");
 381                         printbrush = true;
 382                 }
 383         }
 384         if (printbrush)
 385                 Collision_PrintBrushAsQHull(brush, "unnamed");
 386 }
 387
 388 float nearestplanedist_float(const float *normal, const colpointf_t *points, int numpoints)
 389 {
 390         float dist, bestdist;
 391         bestdist = DotProduct(points->v, normal);
 392         points++;
 393         while(--numpoints)
 394         {
 395                 dist = DotProduct(points->v, normal);
 396                 bestdist = min(bestdist, dist);
 397                 points++;
 398         }
 399         return bestdist;
 400 }
 401
 402 float furthestplanedist_float(const float *normal, const colpointf_t *points, int numpoints)
 403 {
 404         float dist, bestdist;
 405         bestdist = DotProduct(points->v, normal);
 406         points++;
 407         while(--numpoints)
 408         {
 409                 dist = DotProduct(points->v, normal);
 410                 bestdist = max(bestdist, dist);
 411                 points++;
 412         }
 413         return bestdist;
 414 }
 415
 416
 417 colbrushf_t *Collision_NewBrushFromPlanes(mempool_t *mempool, int numoriginalplanes, const mplane_t *originalplanes, int supercontents)
 418 {
 419         int j, k, m, w;
 420         int numpointsbuf = 0, maxpointsbuf = 256, numplanesbuf = 0, maxplanesbuf = 256, numelementsbuf = 0, maxelementsbuf = 256;
 421         colbrushf_t *brush;
 422         colpointf_t pointsbuf[256];
 423         colplanef_t planesbuf[256];
 424         int elementsbuf[1024];
 425         int polypointbuf[256];
 426         int pmaxpoints = 64;
 427         int pnumpoints;
 428         double p[2][3*64];
 429 #if 0
 430         // enable these if debugging to avoid seeing garbage in unused data
 431         memset(pointsbuf, 0, sizeof(pointsbuf));
 432         memset(planesbuf, 0, sizeof(planesbuf));
 433         memset(elementsbuf, 0, sizeof(elementsbuf));
 434         memset(polypointbuf, 0, sizeof(polypointbuf));
 435         memset(p, 0, sizeof(p));
 436 #endif
 437         // construct a collision brush (points, planes, and renderable mesh) from
 438         // a set of planes, this also optimizes out any unnecessary planes (ones
 439         // whose polygon is clipped away by the other planes)
 440         for (j = 0;j < numoriginalplanes;j++)
 441         {
 442                 // add the plane uniquely (no duplicates)
 443                 for (k = 0;k < numplanesbuf;k++)
 444                         if (VectorCompare(planesbuf[k].normal, originalplanes[j].normal) && planesbuf[k].dist == originalplanes[j].dist)
 445                                 break;
 446                 // if the plane is a duplicate, skip it
 447                 if (k < numplanesbuf)
 448                         continue;
 449                 // check if there are too many and skip the brush
 450                 if (numplanesbuf >= maxplanesbuf)
 451                 {
 452                         Con_Print("Mod_Q3BSP_LoadBrushes: failed to build collision brush: too many planes for buffer\n");
 453                         return NULL;
 454                 }
 455
 456                 // create a large polygon from the plane
 457                 w = 0;
 458                 PolygonD_QuadForPlane(p[w], originalplanes[j].normal[0], originalplanes[j].normal[1], originalplanes[j].normal[2], originalplanes[j].dist, 1024.0*1024.0*1024.0);
 459                 pnumpoints = 4;
 460                 // clip it by all other planes
 461                 for (k = 0;k < numoriginalplanes && pnumpoints && pnumpoints <= pmaxpoints;k++)
 462                 {
 463                         if (k != j)
 464                         {
 465                                 // we want to keep the inside of the brush plane so we flip
 466                                 // the cutting plane
 467                                 PolygonD_Divide(pnumpoints, p[w], -originalplanes[k].normal[0], -originalplanes[k].normal[1], -originalplanes[k].normal[2], -originalplanes[k].dist, 1.0/32.0, pmaxpoints, p[!w], &pnumpoints, 0, NULL, NULL);
 468                                 w = !w;
 469                         }
 470                 }
 471                 // if nothing is left, skip it
 472                 if (pnumpoints < 3)
 473                 {
 474                         //Con_Printf("Collision_NewBrushFromPlanes: warning: polygon for plane %f %f %f %f clipped away\n", originalplanes[j].normal[0], originalplanes[j].normal[1], originalplanes[j].normal[2], originalplanes[j].dist);
 475                         continue;
 476                 }
 477
 478                 for (k = 0;k < pnumpoints;k++)
 479                 {
 480                         int l, m;
 481                         m = 0;
 482                         for (l = 0;l < numoriginalplanes;l++)
 483                                 if (fabs(DotProduct(&p[w][k*3], originalplanes[l].normal) - originalplanes[l].dist) < 1.0/8.0)
 484                                         m++;
 485                         if (m < 3)
 486                                 break;
 487                 }
 488                 if (k < pnumpoints)
 489                 {
 490                         Con_Printf("Collision_NewBrushFromPlanes: warning: polygon point does not lie on at least 3 planes\n");
 491                         //return NULL;
 492                 }
 493
 494                 // check if there are too many polygon vertices for buffer
 495                 if (pnumpoints > pmaxpoints)
 496                 {
 497                         Con_Print("Collision_NewBrushFromPlanes: failed to build collision brush: too many points for buffer\n");
 498                         return NULL;
 499                 }
 500
 501                 // check if there are too many triangle elements for buffer
 502                 if (numelementsbuf + (pnumpoints - 2) * 3 > maxelementsbuf)
 503                 {
 504                         Con_Print("Collision_NewBrushFromPlanes: failed to build collision brush: too many triangle elements for buffer\n");
 505                         return NULL;
 506                 }
 507
 508                 for (k = 0;k < pnumpoints;k++)
 509                 {
 510                         // check if there is already a matching point (no duplicates)
 511                         for (m = 0;m < numpointsbuf;m++)
 512                                 if (VectorDistance2(&p[w][k*3], pointsbuf[m].v) < COLLISION_SNAP)
 513                                         break;
 514
 515                         // if there is no match, add a new one
 516                         if (m == numpointsbuf)
 517                         {
 518                                 // check if there are too many and skip the brush
 519                                 if (numpointsbuf >= maxpointsbuf)
 520                                 {
 521                                         Con_Print("Collision_NewBrushFromPlanes: failed to build collision brush: too many points for buffer\n");
 522                                         return NULL;
 523                                 }
 524                                 // add the new one
 525                                 VectorCopy(&p[w][k*3], pointsbuf[numpointsbuf].v);
 526                                 numpointsbuf++;
 527                         }
 528
 529                         // store the index into a buffer
 530                         polypointbuf[k] = m;
 531                 }
 532
 533                 // add the triangles for the polygon
 534                 // (this particular code makes a triangle fan)
 535                 for (k = 0;k < pnumpoints - 2;k++)
 536                 {
 537                         elementsbuf[numelementsbuf++] = polypointbuf[0];
 538                         elementsbuf[numelementsbuf++] = polypointbuf[k + 1];
 539                         elementsbuf[numelementsbuf++] = polypointbuf[k + 2];
 540                 }
 541
 542                 // add the new plane
 543                 VectorCopy(originalplanes[j].normal, planesbuf[numplanesbuf].normal);
 544                 planesbuf[numplanesbuf].dist = originalplanes[j].dist;
 545                 numplanesbuf++;
 546         }
 547
 548         // validate plane distances
 549         for (j = 0;j < numplanesbuf;j++)
 550         {
 551                 float d = furthestplanedist_float(planesbuf[j].normal, pointsbuf, numpointsbuf);
 552                 if (fabs(planesbuf[j].dist - d) > (1.0f/32.0f))
 553                         Con_Printf("plane %f %f %f %f mismatches dist %f\n", planesbuf[j].normal[0], planesbuf[j].normal[1], planesbuf[j].normal[2], planesbuf[j].dist, d);
 554         }
 555
 556         // if nothing is left, there's nothing to allocate
 557         if (numelementsbuf < 12 || numplanesbuf < 4 || numpointsbuf < 4)
 558         {
 559                 Con_Printf("Collision_NewBrushFromPlanes: failed to build collision brush: %i triangles, %i planes (input was %i planes), %i vertices\n", numelementsbuf / 3, numplanesbuf, numoriginalplanes, numpointsbuf);
 560                 return NULL;
 561         }
 562
 563         // allocate the brush and copy to it
 564         brush = Collision_AllocBrushFloat(mempool, numpointsbuf, numplanesbuf, numelementsbuf / 3, supercontents);
 565         for (j = 0;j < brush->numpoints;j++)
 566         {
 567                 brush->points[j].v[0] = pointsbuf[j].v[0];
 568                 brush->points[j].v[1] = pointsbuf[j].v[1];
 569                 brush->points[j].v[2] = pointsbuf[j].v[2];
 570         }
 571         for (j = 0;j < brush->numplanes;j++)
 572         {
 573                 brush->planes[j].normal[0] = planesbuf[j].normal[0];
 574                 brush->planes[j].normal[1] = planesbuf[j].normal[1];
 575                 brush->planes[j].normal[2] = planesbuf[j].normal[2];
 576                 brush->planes[j].dist = planesbuf[j].dist;
 577         }
 578         for (j = 0;j < brush->numtriangles * 3;j++)
 579                 brush->elements[j] = elementsbuf[j];
 580         VectorCopy(brush->points[0].v, brush->mins);
 581         VectorCopy(brush->points[0].v, brush->maxs);
 582         for (j = 1;j < brush->numpoints;j++)
 583         {
 584                 brush->mins[0] = min(brush->mins[0], brush->points[j].v[0]);
 585                 brush->mins[1] = min(brush->mins[1], brush->points[j].v[1]);
 586                 brush->mins[2] = min(brush->mins[2], brush->points[j].v[2]);
 587                 brush->maxs[0] = max(brush->maxs[0], brush->points[j].v[0]);
 588                 brush->maxs[1] = max(brush->maxs[1], brush->points[j].v[1]);
 589                 brush->maxs[2] = max(brush->maxs[2], brush->points[j].v[2]);
 590         }
 591         brush->mins[0] -= 1;
 592         brush->mins[1] -= 1;
 593         brush->mins[2] -= 1;
 594         brush->maxs[0] += 1;
 595         brush->maxs[1] += 1;
 596         brush->maxs[2] += 1;
 597         Collision_ValidateBrush(brush);
 598         return brush;
 599 }
 600
 601
 602
 603 colbrushf_t *Collision_AllocBrushFloat(mempool_t *mempool, int numpoints, int numplanes, int numtriangles, int supercontents)
 604 {
 605         colbrushf_t *brush;
 606         brush = Mem_Alloc(mempool, sizeof(colbrushf_t) + sizeof(colpointf_t) * numpoints + sizeof(colplanef_t) * numplanes + sizeof(int[3]) * numtriangles);
 607         brush->supercontents = supercontents;
 608         brush->numplanes = numplanes;
 609         brush->numpoints = numpoints;
 610         brush->numtriangles = numtriangles;
 611         brush->planes = (void *)(brush + 1);
 612         brush->points = (void *)(brush->planes + brush->numplanes);
 613         brush->elements = (void *)(brush->points + brush->numpoints);
 614         return brush;
 615 }
 616
 617 void Collision_CalcPlanesForPolygonBrushFloat(colbrushf_t *brush)
 618 {
 619         int i;
 620         float edge0[3], edge1[3], edge2[3], normal[3], dist, bestdist;
 621         colpointf_t *p, *p2;
 622
 623         if (brush->numpoints == 3)
 624         {
 625                 // optimized triangle case
 626                 TriangleNormal(brush->points[0].v, brush->points[1].v, brush->points[2].v, brush->planes[0].normal);
 627                 if (DotProduct(brush->planes[0].normal, brush->planes[0].normal) < 0.0001f)
 628                 {
 629                         // there's no point in processing a degenerate triangle (GIGO - Garbage In, Garbage Out)
 630                         brush->numplanes = 0;
 631                         return;
 632                 }
 633                 else
 634                 {
 635                         brush->numplanes = 5;
 636                         VectorNormalize(brush->planes[0].normal);
 637                         brush->planes[0].dist = DotProduct(brush->points->v, brush->planes[0].normal);
 638                         VectorNegate(brush->planes[0].normal, brush->planes[1].normal);
 639                         brush->planes[1].dist = -brush->planes[0].dist;
 640                         VectorSubtract(brush->points[2].v, brush->points[0].v, edge0);
 641                         VectorSubtract(brush->points[0].v, brush->points[1].v, edge1);
 642                         VectorSubtract(brush->points[1].v, brush->points[2].v, edge2);
 643 #if 1
 644                         {
 645                                 float projectionnormal[3], projectionedge0[3], projectionedge1[3], projectionedge2[3];
 646                                 int i, best;
 647                                 float dist, bestdist;
 648                                 bestdist = fabs(brush->planes[0].normal[0]);
 649                                 best = 0;
 650                                 for (i = 1;i < 3;i++)
 651                                 {
 652                                         dist = fabs(brush->planes[0].normal[i]);
 653                                         if (bestdist < dist)
 654                                         {
 655                                                 bestdist = dist;
 656                                                 best = i;
 657                                         }
 658                                 }
 659                                 VectorClear(projectionnormal);
 660                                 if (brush->planes[0].normal[best] < 0)
 661                                         projectionnormal[best] = -1;
 662                                 else
 663                                         projectionnormal[best] = 1;
 664                                 VectorCopy(edge0, projectionedge0);
 665                                 VectorCopy(edge1, projectionedge1);
 666                                 VectorCopy(edge2, projectionedge2);
 667                                 projectionedge0[best] = 0;
 668                                 projectionedge1[best] = 0;
 669                                 projectionedge2[best] = 0;
 670                                 CrossProduct(projectionedge0, projectionnormal, brush->planes[2].normal);
 671                                 CrossProduct(projectionedge1, projectionnormal, brush->planes[3].normal);
 672                                 CrossProduct(projectionedge2, projectionnormal, brush->planes[4].normal);
 673                         }
 674 #else
 675                         CrossProduct(edge0, brush->planes->normal, brush->planes[2].normal);
 676                         CrossProduct(edge1, brush->planes->normal, brush->planes[3].normal);
 677                         CrossProduct(edge2, brush->planes->normal, brush->planes[4].normal);
 678 #endif
 679                         VectorNormalize(brush->planes[2].normal);
 680                         VectorNormalize(brush->planes[3].normal);
 681                         VectorNormalize(brush->planes[4].normal);
 682                         brush->planes[2].dist = DotProduct(brush->points[2].v, brush->planes[2].normal);
 683                         brush->planes[3].dist = DotProduct(brush->points[0].v, brush->planes[3].normal);
 684                         brush->planes[4].dist = DotProduct(brush->points[1].v, brush->planes[4].normal);
 685
 686                         if (developer.integer)
 687                         {
 688                                 // validation code
 689 #if 0
 690                                 float temp[3];
 691
 692                                 VectorSubtract(brush->points[0].v, brush->points[1].v, edge0);
 693                                 VectorSubtract(brush->points[2].v, brush->points[1].v, edge1);
 694                                 CrossProduct(edge0, edge1, normal);
 695                                 VectorNormalize(normal);
 696                                 VectorSubtract(normal, brush->planes[0].normal, temp);
 697                                 if (VectorLength(temp) > 0.01f)
 698                                         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]);
 699                                 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)
 700                                         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);
 701 #if 0
 702                                 if (fabs(DotProduct(brush->planes[2].normal, brush->planes[0].normal)) > 0.01f)
 703                                         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);
 704                                 if (fabs(DotProduct(brush->planes[3].normal, brush->planes[0].normal)) > 0.01f)
 705                                         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);
 706                                 if (fabs(DotProduct(brush->planes[4].normal, brush->planes[0].normal)) > 0.01f)
 707                                         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);
 708                                 if (fabs(DotProduct(brush->planes[2].normal, edge0)) > 0.01f)
 709                                         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]);
 710                                 if (fabs(DotProduct(brush->planes[3].normal, edge1)) > 0.01f)
 711                                         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]);
 712                                 if (fabs(DotProduct(brush->planes[4].normal, edge2)) > 0.01f)
 713                                         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]);
 714 #endif
 715 #endif
 716                                 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)
 717                                         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);
 718                                 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)
 719                                         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);
 720                                 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)
 721                                         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);
 722                                 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)
 723                                         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);
 724                                 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)
 725                                         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);
 726                         }
 727                 }
 728         }
 729         else
 730         {
 731                 // choose best surface normal for polygon's plane
 732                 bestdist = 0;
 733                 for (i = 0, p = brush->points + 1;i < brush->numpoints - 2;i++, p++)
 734                 {
 735                         VectorSubtract(p[-1].v, p[0].v, edge0);
 736                         VectorSubtract(p[1].v, p[0].v, edge1);
 737                         CrossProduct(edge0, edge1, normal);
 738                         //TriangleNormal(p[-1].v, p[0].v, p[1].v, normal);
 739                         dist = DotProduct(normal, normal);
 740                         if (i == 0 || bestdist < dist)
 741                         {
 742                                 bestdist = dist;
 743                                 VectorCopy(normal, brush->planes->normal);
 744                         }
 745                 }
 746                 if (bestdist < 0.0001f)
 747                 {
 748                         // there's no point in processing a degenerate triangle (GIGO - Garbage In, Garbage Out)
 749                         brush->numplanes = 0;
 750                         return;
 751                 }
 752                 else
 753                 {
 754                         brush->numplanes = brush->numpoints + 2;
 755                         VectorNormalize(brush->planes->normal);
 756                         brush->planes->dist = DotProduct(brush->points->v, brush->planes->normal);
 757
 758                         // negate plane to create other side
 759                         VectorNegate(brush->planes[0].normal, brush->planes[1].normal);
 760                         brush->planes[1].dist = -brush->planes[0].dist;
 761                         for (i = 0, p = brush->points + (brush->numpoints - 1), p2 = brush->points;i < brush->numpoints;i++, p = p2, p2++)
 762                         {
 763                                 VectorSubtract(p->v, p2->v, edge0);
 764                                 CrossProduct(edge0, brush->planes->normal, brush->planes[i + 2].normal);
 765                                 VectorNormalize(brush->planes[i + 2].normal);
 766                                 brush->planes[i + 2].dist = DotProduct(p->v, brush->planes[i + 2].normal);
 767                         }
 768                 }
 769         }
 770
 771         if (developer.integer)
 772         {
 773                 // validity check - will be disabled later
 774                 Collision_ValidateBrush(brush);
 775                 for (i = 0;i < brush->numplanes;i++)
 776                 {
 777                         int j;
 778                         for (j = 0, p = brush->points;j < brush->numpoints;j++, p++)
 779                                 if (DotProduct(p->v, brush->planes[i].normal) > brush->planes[i].dist + (1.0 / 32.0))
 780                                         Con_Printf("Error in brush plane generation, plane %i\n", i);
 781                 }
 782         }
 783 }
 784
 785 colbrushf_t *Collision_AllocBrushFromPermanentPolygonFloat(mempool_t *mempool, int numpoints, float *points, int supercontents)
 786 {
 787         colbrushf_t *brush;
 788         brush = Mem_Alloc(mempool, sizeof(colbrushf_t) + sizeof(colplanef_t) * (numpoints + 2));
 789         brush->supercontents = supercontents;
 790         brush->numpoints = numpoints;
 791         brush->numplanes = numpoints + 2;
 792         brush->planes = (void *)(brush + 1);
 793         brush->points = (colpointf_t *)points;
 794         Host_Error("Collision_AllocBrushFromPermanentPolygonFloat: FIXME: this code needs to be updated to generate a mesh...\n");
 795         return brush;
 796 }
 797
 798 // NOTE: start and end of each brush pair must have same numplanes/numpoints
 799 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)
 800 {
 801         int nplane, nplane2, fstartsolid, fendsolid, brushsolid;
 802         float enterfrac, leavefrac, d1, d2, f, move, imove, newimpactnormal[3], enterfrac2;
 803         const colplanef_t *startplane, *endplane;
 804
 805         enterfrac = -1;
 806         enterfrac2 = -1;
 807         leavefrac = 1;
 808         fstartsolid = true;
 809         fendsolid = true;
 810
 811         for (nplane = 0;nplane < thatbrush_start->numplanes + thisbrush_start->numplanes;nplane++)
 812         {
 813                 nplane2 = nplane;
 814                 if (nplane2 >= thatbrush_start->numplanes)
 815                 {
 816                         nplane2 -= thatbrush_start->numplanes;
 817                         startplane = thisbrush_start->planes + nplane2;
 818                         endplane = thisbrush_end->planes + nplane2;
 819                         if (developer.integer)
 820                         {
 821                                 // any brush with degenerate planes is not worth handling
 822                                 if (DotProduct(startplane->normal, startplane->normal) < 0.9f || DotProduct(endplane->normal, endplane->normal) < 0.9f)
 823                                 {
 824                                         Con_Print("Collision_TraceBrushBrushFloat: degenerate thisbrush plane!\n");
 825                                         return;
 826                                 }
 827                                 f = furthestplanedist_float(startplane->normal, thisbrush_start->points, thisbrush_start->numpoints);
 828                                 if (fabs(f - startplane->dist) > 0.125f)
 829                                         Con_Printf("startplane->dist %f != calculated %f (thisbrush_start)\n", startplane->dist, f);
 830                         }
 831                         d1 = nearestplanedist_float(startplane->normal, thisbrush_start->points, thisbrush_start->numpoints) - furthestplanedist_float(startplane->normal, thatbrush_start->points, thatbrush_start->numpoints) - collision_startnudge.value;
 832                         d2 = nearestplanedist_float(endplane->normal, thisbrush_end->points, thisbrush_end->numpoints) - furthestplanedist_float(endplane->normal, thatbrush_end->points, thatbrush_end->numpoints) - collision_endnudge.value;
 833                 }
 834                 else
 835                 {
 836                         startplane = thatbrush_start->planes + nplane2;
 837                         endplane = thatbrush_end->planes + nplane2;
 838                         if (developer.integer)
 839                         {
 840                                 // any brush with degenerate planes is not worth handling
 841                                 if (DotProduct(startplane->normal, startplane->normal) < 0.9f || DotProduct(endplane->normal, endplane->normal) < 0.9f)
 842                                 {
 843                                         Con_Print("Collision_TraceBrushBrushFloat: degenerate thatbrush plane!\n");
 844                                         return;
 845                                 }
 846                                 f = furthestplanedist_float(startplane->normal, thatbrush_start->points, thatbrush_start->numpoints);
 847                                 if (fabs(f - startplane->dist) > 0.125f)
 848                                         Con_Printf("startplane->dist %f != calculated %f (thatbrush_start)\n", startplane->dist, f);
 849                         }
 850                         d1 = nearestplanedist_float(startplane->normal, thisbrush_start->points, thisbrush_start->numpoints) - startplane->dist - collision_startnudge.value;
 851                         d2 = nearestplanedist_float(endplane->normal, thisbrush_end->points, thisbrush_end->numpoints) - endplane->dist - collision_endnudge.value;
 852                 }
 853                 //Con_Printf("%c%i: d1 = %f, d2 = %f, d1 / (d1 - d2) = %f\n", nplane2 != nplane ? 'b' : 'a', nplane2, d1, d2, d1 / (d1 - d2));
 854
 855                 move = d1 - d2;
 856                 if (move > 0)
 857                 {
 858                         // moving into brush
 859                         if (d2 > collision_enternudge.value)
 860                                 return;
 861                         if (d1 < 0)
 862                                 continue;
 863                         // enter
 864                         fstartsolid = false;
 865                         imove = 1 / move;
 866                         f = (d1 - collision_enternudge.value) * imove;
 867                         f = bound(0, f, 1);
 868                         if (enterfrac < f)
 869                         {
 870                                 enterfrac = f;
 871                                 enterfrac2 = f - collision_impactnudge.value * imove;
 872                                 enterfrac2 = bound(0, enterfrac2, 1);
 873                                 VectorLerp(startplane->normal, enterfrac, endplane->normal, newimpactnormal);
 874                         }
 875                 }
 876                 else if (move < 0)
 877                 {
 878                         // moving out of brush
 879                         if (d1 > collision_leavenudge.value)
 880                                 return;
 881                         if (d2 < 0)
 882                                 continue;
 883                         // leave
 884                         fendsolid = false;
 885                         f = (d1 + collision_leavenudge.value) / move;
 886                         f = bound(0, f, 1);
 887                         if (leavefrac > f)
 888                                 leavefrac = f;
 889                 }
 890                 else
 891                 {
 892                         // sliding along plane
 893                         if (d1 > 0)
 894                                 return;
 895                 }
 896         }
 897
 898         brushsolid = trace->hitsupercontentsmask & thatbrush_start->supercontents;
 899         if (fstartsolid)
 900         {
 901                 trace->startsupercontents |= thatbrush_start->supercontents;
 902                 if (brushsolid)
 903                 {
 904                         trace->startsolid = true;
 905                         if (fendsolid)
 906                                 trace->allsolid = true;
 907                 }
 908         }
 909
 910         // LordHavoc: we need an epsilon nudge here because for a point trace the
 911         // penetrating line segment is normally zero length if this brush was
 912         // generated from a polygon (infinitely thin), and could even be slightly
 913         // positive or negative due to rounding errors in that case.
 914         if (brushsolid && enterfrac > -1 && enterfrac < trace->realfraction && enterfrac - (1.0f / 1024.0f) <= leavefrac)
 915         {
 916 #if 0
 917                 // broken
 918                 if (thatbrush_start->ispolygon)
 919                 {
 920                         d1 = nearestplanedist_float(thatbrush_start->planes[0].normal, thisbrush_start->points, thisbrush_start->numpoints) - thatbrush_start->planes[0].dist - collision_startnudge.value;
 921                         d2 = nearestplanedist_float(thatbrush_end->planes[0].normal, thisbrush_end->points, thisbrush_end->numpoints) - thatbrush_end->planes[0].dist - collision_endnudge.value;
 922                         move = d1 - d2;
 923                         if (move <= 0 || d2 > collision_enternudge.value || d1 < 0)
 924                                 return;
 925                         // enter
 926                         imove = 1 / move;
 927                         enterfrac = (d1 - collision_enternudge.value) * imove;
 928                         if (enterfrac < trace->realfraction)
 929                         {
 930                                 enterfrac2 = enterfrac - collision_impactnudge.value * imove;
 931                                 trace->realfraction = bound(0, enterfrac, 1);
 932                                 trace->fraction = bound(0, enterfrac2, 1);
 933                                 VectorLerp(thatbrush_start->planes[0].normal, enterfrac, thatbrush_end->planes[0].normal, trace->plane.normal);
 934                         }
 935                 }
 936                 else
 937 #endif
 938                 {
 939                         trace->realfraction = bound(0, enterfrac, 1);
 940                         trace->fraction = bound(0, enterfrac2, 1);
 941                         VectorCopy(newimpactnormal, trace->plane.normal);
 942                 }
 943         }
 944 }
 945
 946 // NOTE: start and end brush pair must have same numplanes/numpoints
 947 void Collision_TraceLineBrushFloat(trace_t *trace, const vec3_t linestart, const vec3_t lineend, const colbrushf_t *thatbrush_start, const colbrushf_t *thatbrush_end)
 948 {
 949         int nplane, fstartsolid, fendsolid, brushsolid;
 950         float enterfrac, leavefrac, d1, d2, f, move, imove, newimpactnormal[3], enterfrac2;
 951         const colplanef_t *startplane, *endplane;
 952
 953         enterfrac = -1;
 954         enterfrac2 = -1;
 955         leavefrac = 1;
 956         fstartsolid = true;
 957         fendsolid = true;
 958
 959         for (nplane = 0;nplane < thatbrush_start->numplanes;nplane++)
 960         {
 961                 startplane = thatbrush_start->planes + nplane;
 962                 endplane = thatbrush_end->planes + nplane;
 963                 d1 = DotProduct(startplane->normal, linestart) - startplane->dist - collision_startnudge.value;
 964                 d2 = DotProduct(endplane->normal, lineend) - endplane->dist - collision_endnudge.value;
 965                 if (developer.integer)
 966                 {
 967                         // any brush with degenerate planes is not worth handling
 968                         if (DotProduct(startplane->normal, startplane->normal) < 0.9f || DotProduct(endplane->normal, endplane->normal) < 0.9f)
 969                         {
 970                                 Con_Print("Collision_TraceLineBrushFloat: degenerate plane!\n");
 971                                 return;
 972                         }
 973                         if (thatbrush_start->numpoints)
 974                         {
 975                                 f = furthestplanedist_float(startplane->normal, thatbrush_start->points, thatbrush_start->numpoints);
 976                                 if (fabs(f - startplane->dist) > 0.125f)
 977                                         Con_Printf("startplane->dist %f != calculated %f\n", startplane->dist, f);
 978                         }
 979                 }
 980
 981                 move = d1 - d2;
 982                 if (move > 0)
 983                 {
 984                         // moving into brush
 985                         if (d2 >= 0)
 986                                 return;
 987                         if (d1 <= 0)
 988                                 continue;
 989                         // enter
 990                         fstartsolid = false;
 991                         imove = 1 / move;
 992                         f = (d1 - collision_enternudge.value) * imove;
 993                         if (enterfrac < f)
 994                         {
 995                                 enterfrac = f;
 996                                 enterfrac2 = f - collision_impactnudge.value * imove;
 997                                 VectorLerp(startplane->normal, enterfrac, endplane->normal, newimpactnormal);
 998                         }
 999                 }
1000                 else
1001                 {
1002                         // moving out of brush
1003                         if (d1 >= 0)
1004                                 return;
1005                         if (d2 <= 0)
1006                                 continue;
1007                         // leave
1008                         fendsolid = false;
1009                         f = (d1 - collision_leavenudge.value) / move;
1010                         if (leavefrac > f)
1011                                 leavefrac = f;
1012                 }
1013         }
1014
1015         brushsolid = trace->hitsupercontentsmask & thatbrush_start->supercontents;
1016         if (fstartsolid)
1017         {
1018                 trace->startsupercontents |= thatbrush_start->supercontents;
1019                 if (brushsolid)
1020                 {
1021                         trace->startsolid = true;
1022                         if (fendsolid)
1023                                 trace->allsolid = true;
1024                 }
1025         }
1026
1027         // LordHavoc: we need an epsilon nudge here because for a point trace the
1028         // penetrating line segment is normally zero length if this brush was
1029         // generated from a polygon (infinitely thin), and could even be slightly
1030         // positive or negative due to rounding errors in that case.
1031         if (brushsolid && enterfrac > -1 && enterfrac < trace->realfraction && enterfrac - (1.0f / 1024.0f) <= leavefrac)
1032         {
1033 #if 0
1034                 // broken
1035                 if (thatbrush_start->ispolygon)
1036                 {
1037                         d1 = DotProduct(thatbrush_start->planes[0].normal, linestart) - thatbrush_start->planes[0].dist - collision_startnudge.value;
1038                         d2 = DotProduct(thatbrush_end->planes[0].normal, lineend) - thatbrush_end->planes[0].dist - collision_endnudge.value;
1039                         move = d1 - d2;
1040                         if (move <= 0 || d2 > collision_enternudge.value || d1 < 0)
1041                                 return;
1042                         // enter
1043                         imove = 1 / move;
1044                         enterfrac = (d1 - collision_enternudge.value) * imove;
1045                         if (enterfrac < trace->realfraction)
1046                         {
1047                                 enterfrac2 = enterfrac - collision_impactnudge.value * imove;
1048                                 trace->realfraction = bound(0, enterfrac, 1);
1049                                 trace->fraction = bound(0, enterfrac2, 1);
1050                                 VectorLerp(thatbrush_start->planes[0].normal, enterfrac, thatbrush_end->planes[0].normal, trace->plane.normal);
1051                         }
1052                 }
1053                 else
1054 #endif
1055                 {
1056                         trace->realfraction = bound(0, enterfrac, 1);
1057                         trace->fraction = bound(0, enterfrac2, 1);
1058                         VectorCopy(newimpactnormal, trace->plane.normal);
1059                 }
1060         }
1061 }
1062
1063 void Collision_TracePointBrushFloat(trace_t *trace, const vec3_t point, const colbrushf_t *thatbrush)
1064 {
1065         int nplane;
1066         const colplanef_t *plane;
1067
1068         for (nplane = 0, plane = thatbrush->planes;nplane < thatbrush->numplanes;nplane++, plane++)
1069                 if (DotProduct(plane->normal, point) > plane->dist)
1070                         return;
1071
1072         trace->startsupercontents |= thatbrush->supercontents;
1073         if (trace->hitsupercontentsmask & thatbrush->supercontents)
1074         {
1075                 trace->startsolid = true;
1076                 trace->allsolid = true;
1077         }
1078 }
1079
1080 static colpointf_t polyf_points[256];
1081 static colplanef_t polyf_planes[256 + 2];
1082 static colbrushf_t polyf_brush;
1083
1084 void Collision_SnapCopyPoints(int numpoints, const colpointf_t *in, colpointf_t *out, float fractionprecision, float invfractionprecision)
1085 {
1086         while (numpoints--)
1087         {
1088                 out->v[0] = floor(in->v[0] * fractionprecision + 0.5f) * invfractionprecision;
1089                 out->v[1] = floor(in->v[1] * fractionprecision + 0.5f) * invfractionprecision;
1090                 out->v[2] = floor(in->v[2] * fractionprecision + 0.5f) * invfractionprecision;
1091         }
1092 }
1093
1094 void Collision_TraceBrushPolygonFloat(trace_t *trace, const colbrushf_t *thisbrush_start, const colbrushf_t *thisbrush_end, int numpoints, const float *points, int supercontents)
1095 {
1096         if (numpoints > 256)
1097         {
1098                 Con_Print("Polygon with more than 256 points not supported yet (fixme!)\n");
1099                 return;
1100         }
1101         polyf_brush.numpoints = numpoints;
1102         polyf_brush.numplanes = numpoints + 2;
1103         //polyf_brush.points = (colpointf_t *)points;
1104         polyf_brush.planes = polyf_planes;
1105         polyf_brush.supercontents = supercontents;
1106         polyf_brush.points = polyf_points;
1107         Collision_SnapCopyPoints(numpoints, (colpointf_t *)points, polyf_points, COLLISION_SNAPSCALE, COLLISION_SNAP);
1108         Collision_CalcPlanesForPolygonBrushFloat(&polyf_brush);
1109         //Collision_PrintBrushAsQHull(&polyf_brush, "polyf_brush");
1110         Collision_TraceBrushBrushFloat(trace, thisbrush_start, thisbrush_end, &polyf_brush, &polyf_brush);
1111 }
1112
1113 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)
1114 {
1115         int i;
1116         float facemins[3], facemaxs[3];
1117         polyf_brush.numpoints = 3;
1118         polyf_brush.numplanes = 5;
1119         polyf_brush.points = polyf_points;
1120         polyf_brush.planes = polyf_planes;
1121         polyf_brush.supercontents = supercontents;
1122         for (i = 0;i < numtriangles;i++, element3i += 3)
1123         {
1124                 VectorCopy(vertex3f + element3i[0] * 3, polyf_points[0].v);
1125                 VectorCopy(vertex3f + element3i[1] * 3, polyf_points[1].v);
1126                 VectorCopy(vertex3f + element3i[2] * 3, polyf_points[2].v);
1127                 Collision_SnapCopyPoints(3, polyf_points, polyf_points, COLLISION_SNAPSCALE, COLLISION_SNAP);
1128                 facemins[0] = min(polyf_points[0].v[0], min(polyf_points[1].v[0], polyf_points[2].v[0])) - 1;
1129                 facemins[1] = min(polyf_points[0].v[1], min(polyf_points[1].v[1], polyf_points[2].v[1])) - 1;
1130                 facemins[2] = min(polyf_points[0].v[2], min(polyf_points[1].v[2], polyf_points[2].v[2])) - 1;
1131                 facemaxs[0] = max(polyf_points[0].v[0], max(polyf_points[1].v[0], polyf_points[2].v[0])) + 1;
1132                 facemaxs[1] = max(polyf_points[0].v[1], max(polyf_points[1].v[1], polyf_points[2].v[1])) + 1;
1133                 facemaxs[2] = max(polyf_points[0].v[2], max(polyf_points[1].v[2], polyf_points[2].v[2])) + 1;
1134                 if (BoxesOverlap(segmentmins, segmentmaxs, facemins, facemaxs))
1135                 {
1136                         Collision_CalcPlanesForPolygonBrushFloat(&polyf_brush);
1137                         //Collision_PrintBrushAsQHull(&polyf_brush, "polyf_brush");
1138                         Collision_TraceBrushBrushFloat(trace, thisbrush_start, thisbrush_end, &polyf_brush, &polyf_brush);
1139                 }
1140         }
1141 }
1142
1143 void Collision_TraceLinePolygonFloat(trace_t *trace, const vec3_t linestart, const vec3_t lineend, int numpoints, const float *points, int supercontents)
1144 {
1145         if (numpoints > 256)
1146         {
1147                 Con_Print("Polygon with more than 256 points not supported yet (fixme!)\n");
1148                 return;
1149         }
1150         polyf_brush.numpoints = numpoints;
1151         polyf_brush.numplanes = numpoints + 2;
1152         //polyf_brush.points = (colpointf_t *)points;
1153         polyf_brush.points = polyf_points;
1154         Collision_SnapCopyPoints(numpoints, (colpointf_t *)points, polyf_points, COLLISION_SNAPSCALE, COLLISION_SNAP);
1155         polyf_brush.planes = polyf_planes;
1156         polyf_brush.supercontents = supercontents;
1157         Collision_CalcPlanesForPolygonBrushFloat(&polyf_brush);
1158         //Collision_PrintBrushAsQHull(&polyf_brush, "polyf_brush");
1159         Collision_TraceLineBrushFloat(trace, linestart, lineend, &polyf_brush, &polyf_brush);
1160 }
1161
1162 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)
1163 {
1164         int i;
1165 #if 1
1166         // FIXME: snap vertices?
1167         for (i = 0;i < numtriangles;i++, element3i += 3)
1168                 Collision_TraceLineTriangleFloat(trace, linestart, lineend, vertex3f + element3i[0] * 3, vertex3f + element3i[1] * 3, vertex3f + element3i[2] * 3);
1169 #else
1170         polyf_brush.numpoints = 3;
1171         polyf_brush.numplanes = 5;
1172         polyf_brush.points = polyf_points;
1173         polyf_brush.planes = polyf_planes;
1174         polyf_brush.supercontents = supercontents;
1175         for (i = 0;i < numtriangles;i++, element3i += 3)
1176         {
1177                 float facemins[3], facemaxs[3];
1178                 VectorCopy(vertex3f + element3i[0] * 3, polyf_points[0].v);
1179                 VectorCopy(vertex3f + element3i[1] * 3, polyf_points[1].v);
1180                 VectorCopy(vertex3f + element3i[2] * 3, polyf_points[2].v);
1181                 Collision_SnapCopyPoints(numpoints, polyf_points, polyf_points, COLLISION_SNAPSCALE, COLLISION_SNAP);
1182                 facemins[0] = min(polyf_points[0].v[0], min(polyf_points[1].v[0], polyf_points[2].v[0])) - 1;
1183                 facemins[1] = min(polyf_points[0].v[1], min(polyf_points[1].v[1], polyf_points[2].v[1])) - 1;
1184                 facemins[2] = min(polyf_points[0].v[2], min(polyf_points[1].v[2], polyf_points[2].v[2])) - 1;
1185                 facemaxs[0] = max(polyf_points[0].v[0], max(polyf_points[1].v[0], polyf_points[2].v[0])) + 1;
1186                 facemaxs[1] = max(polyf_points[0].v[1], max(polyf_points[1].v[1], polyf_points[2].v[1])) + 1;
1187                 facemaxs[2] = max(polyf_points[0].v[2], max(polyf_points[1].v[2], polyf_points[2].v[2])) + 1;
1188                 if (BoxesOverlap(segmentmins, segmentmaxs, facemins, facemaxs))
1189                 {
1190                         Collision_CalcPlanesForPolygonBrushFloat(&polyf_brush);
1191                         //Collision_PrintBrushAsQHull(&polyf_brush, "polyf_brush");
1192                         Collision_TraceLineBrushFloat(trace, linestart, lineend, &polyf_brush, &polyf_brush);
1193                 }
1194         }
1195 #endif
1196 }
1197
1198
1199 static colpointf_t polyf_pointsstart[256], polyf_pointsend[256];
1200 static colplanef_t polyf_planesstart[256 + 2], polyf_planesend[256 + 2];
1201 static colbrushf_t polyf_brushstart, polyf_brushend;
1202
1203 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)
1204 {
1205         int i;
1206         if (numpoints > 256)
1207         {
1208                 Con_Print("Polygon with more than 256 points not supported yet (fixme!)\n");
1209                 return;
1210         }
1211         polyf_brushstart.numpoints = numpoints;
1212         polyf_brushstart.numplanes = numpoints + 2;
1213         polyf_brushstart.points = polyf_pointsstart;//(colpointf_t *)points;
1214         polyf_brushstart.planes = polyf_planesstart;
1215         polyf_brushstart.supercontents = supercontents;
1216         for (i = 0;i < numpoints;i++)
1217                 Matrix4x4_Transform(polygonmatrixstart, points + i * 3, polyf_brushstart.points[i].v);
1218         polyf_brushend.numpoints = numpoints;
1219         polyf_brushend.numplanes = numpoints + 2;
1220         polyf_brushend.points = polyf_pointsend;//(colpointf_t *)points;
1221         polyf_brushend.planes = polyf_planesend;
1222         polyf_brushend.supercontents = supercontents;
1223         for (i = 0;i < numpoints;i++)
1224                 Matrix4x4_Transform(polygonmatrixend, points + i * 3, polyf_brushend.points[i].v);
1225         Collision_SnapCopyPoints(numpoints, polyf_pointsstart, polyf_pointsstart, COLLISION_SNAPSCALE, COLLISION_SNAP);
1226         Collision_SnapCopyPoints(numpoints, polyf_pointsend, polyf_pointsend, COLLISION_SNAPSCALE, COLLISION_SNAP);
1227         Collision_CalcPlanesForPolygonBrushFloat(&polyf_brushstart);
1228         Collision_CalcPlanesForPolygonBrushFloat(&polyf_brushend);
1229
1230         //Collision_PrintBrushAsQHull(&polyf_brushstart, "polyf_brushstart");
1231         //Collision_PrintBrushAsQHull(&polyf_brushend, "polyf_brushend");
1232
1233         Collision_TraceBrushBrushFloat(trace, thisbrush_start, thisbrush_end, &polyf_brushstart, &polyf_brushend);
1234 }
1235
1236
1237
1238 #define MAX_BRUSHFORBOX 16
1239 static int brushforbox_index = 0;
1240 static colpointf_t brushforbox_point[MAX_BRUSHFORBOX*8];
1241 static colplanef_t brushforbox_plane[MAX_BRUSHFORBOX*6];
1242 static colbrushf_t brushforbox_brush[MAX_BRUSHFORBOX];
1243 static colbrushf_t brushforpoint_brush[MAX_BRUSHFORBOX];
1244
1245 void Collision_InitBrushForBox(void)
1246 {
1247         int i;
1248         for (i = 0;i < MAX_BRUSHFORBOX;i++)
1249         {
1250                 brushforbox_brush[i].supercontents = SUPERCONTENTS_SOLID;
1251                 brushforbox_brush[i].numpoints = 8;
1252                 brushforbox_brush[i].numplanes = 6;
1253                 brushforbox_brush[i].points = brushforbox_point + i * 8;
1254                 brushforbox_brush[i].planes = brushforbox_plane + i * 6;
1255                 brushforpoint_brush[i].supercontents = SUPERCONTENTS_SOLID;
1256                 brushforpoint_brush[i].numpoints = 1;
1257                 brushforpoint_brush[i].numplanes = 0;
1258                 brushforpoint_brush[i].points = brushforbox_point + i * 8;
1259                 brushforpoint_brush[i].planes = brushforbox_plane + i * 6;
1260         }
1261 }
1262
1263 colbrushf_t *Collision_BrushForBox(const matrix4x4_t *matrix, const vec3_t mins, const vec3_t maxs)
1264 {
1265         int i, j;
1266         vec3_t v;
1267         colbrushf_t *brush;
1268         if (brushforbox_brush[0].numpoints == 0)
1269                 Collision_InitBrushForBox();
1270         if (VectorCompare(mins, maxs))
1271         {
1272                 // point brush
1273                 brush = brushforpoint_brush + ((brushforbox_index++) % MAX_BRUSHFORBOX);
1274                 VectorCopy(mins, brush->points->v);
1275         }
1276         else
1277         {
1278                 brush = brushforbox_brush + ((brushforbox_index++) % MAX_BRUSHFORBOX);
1279                 // FIXME: optimize
1280                 for (i = 0;i < 8;i++)
1281                 {
1282                         v[0] = i & 1 ? maxs[0] : mins[0];
1283                         v[1] = i & 2 ? maxs[1] : mins[1];
1284                         v[2] = i & 4 ? maxs[2] : mins[2];
1285                         Matrix4x4_Transform(matrix, v, brush->points[i].v);
1286                 }
1287                 // FIXME: optimize!
1288                 for (i = 0;i < 6;i++)
1289                 {
1290                         VectorClear(v);
1291                         v[i >> 1] = i & 1 ? 1 : -1;
1292                         Matrix4x4_Transform3x3(matrix, v, brush->planes[i].normal);
1293                         VectorNormalize(brush->planes[i].normal);
1294                 }
1295         }
1296         for (j = 0;j < brush->numplanes;j++)
1297                 brush->planes[j].dist = furthestplanedist_float(brush->planes[j].normal, brush->points, brush->numpoints);
1298         VectorCopy(brush->points[0].v, brush->mins);
1299         VectorCopy(brush->points[0].v, brush->maxs);
1300         for (j = 1;j < brush->numpoints;j++)
1301         {
1302                 brush->mins[0] = min(brush->mins[0], brush->points[j].v[0]);
1303                 brush->mins[1] = min(brush->mins[1], brush->points[j].v[1]);
1304                 brush->mins[2] = min(brush->mins[2], brush->points[j].v[2]);
1305                 brush->maxs[0] = max(brush->maxs[0], brush->points[j].v[0]);
1306                 brush->maxs[1] = max(brush->maxs[1], brush->points[j].v[1]);
1307                 brush->maxs[2] = max(brush->maxs[2], brush->points[j].v[2]);
1308         }
1309         brush->mins[0] -= 1;
1310         brush->mins[1] -= 1;
1311         brush->mins[2] -= 1;
1312         brush->maxs[0] += 1;
1313         brush->maxs[1] += 1;
1314         brush->maxs[2] += 1;
1315         Collision_ValidateBrush(brush);
1316         return brush;
1317 }
1318
1319 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)
1320 {
1321         colbrushf_t *boxbrush, *thisbrush_start, *thisbrush_end;
1322         matrix4x4_t identitymatrix;
1323         vec3_t startmins, startmaxs, endmins, endmaxs;
1324
1325         // create brushes for the collision
1326         VectorAdd(start, mins, startmins);
1327         VectorAdd(start, maxs, startmaxs);
1328         VectorAdd(end, mins, endmins);
1329         VectorAdd(end, maxs, endmaxs);
1330         Matrix4x4_CreateIdentity(&identitymatrix);
1331         boxbrush = Collision_BrushForBox(&identitymatrix, cmins, cmaxs);
1332         thisbrush_start = Collision_BrushForBox(&identitymatrix, startmins, startmaxs);
1333         thisbrush_end = Collision_BrushForBox(&identitymatrix, endmins, endmaxs);
1334
1335         memset(trace, 0, sizeof(trace_t));
1336         trace->hitsupercontentsmask = hitsupercontentsmask;
1337         trace->fraction = 1;
1338         trace->realfraction = 1;
1339         trace->allsolid = true;
1340         Collision_TraceBrushBrushFloat(trace, thisbrush_start, thisbrush_end, boxbrush, boxbrush);
1341 }
1342
1343 // LordHavoc: currently unused and not yet tested
1344 // note: this can be used for tracing a moving sphere vs a stationary sphere,
1345 // by simply adding the moving sphere's radius to the sphereradius parameter,
1346 // all the results are correct (impactpoint, impactnormal, and fraction)
1347 float Collision_ClipTrace_Line_Sphere(double *linestart, double *lineend, double *sphereorigin, double sphereradius, double *impactpoint, double *impactnormal)
1348 {
1349         double dir[3], scale, v[3], deviationdist, impactdist, linelength;
1350         // make sure the impactpoint and impactnormal are valid even if there is
1351         // no collision
1352         impactpoint[0] = lineend[0];
1353         impactpoint[1] = lineend[1];
1354         impactpoint[2] = lineend[2];
1355         impactnormal[0] = 0;
1356         impactnormal[1] = 0;
1357         impactnormal[2] = 0;
1358         // calculate line direction
1359         dir[0] = lineend[0] - linestart[0];
1360         dir[1] = lineend[1] - linestart[1];
1361         dir[2] = lineend[2] - linestart[2];
1362         // normalize direction
1363         linelength = sqrt(dir[0] * dir[0] + dir[1] * dir[1] + dir[2] * dir[2]);
1364         if (linelength)
1365         {
1366                 scale = 1.0 / linelength;
1367                 dir[0] *= scale;
1368                 dir[1] *= scale;
1369                 dir[2] *= scale;
1370         }
1371         // this dotproduct calculates the distance along the line at which the
1372         // sphere origin is (nearest point to the sphere origin on the line)
1373         impactdist = dir[0] * (sphereorigin[0] - linestart[0]) + dir[1] * (sphereorigin[1] - linestart[1]) + dir[2] * (sphereorigin[2] - linestart[2]);
1374         // calculate point on line at that distance, and subtract the
1375         // sphereorigin from it, so we have a vector to measure for the distance
1376         // of the line from the sphereorigin (deviation, how off-center it is)
1377         v[0] = linestart[0] + impactdist * dir[0] - sphereorigin[0];
1378         v[1] = linestart[1] + impactdist * dir[1] - sphereorigin[1];
1379         v[2] = linestart[2] + impactdist * dir[2] - sphereorigin[2];
1380         deviationdist = v[0] * v[0] + v[1] * v[1] + v[2] * v[2];
1381         // if outside the radius, it's a miss for sure
1382         // (we do this comparison using squared radius to avoid a sqrt)
1383         if (deviationdist > sphereradius*sphereradius)
1384                 return 1; // miss (off to the side)
1385         // nudge back to find the correct impact distance
1386         impactdist += (sqrt(deviationdist) - sphereradius);
1387         if (impactdist >= linelength)
1388                 return 1; // miss (not close enough)
1389         if (impactdist < 0)
1390                 return 1; // miss (linestart is past or inside sphere)
1391         // calculate new impactpoint
1392         impactpoint[0] = linestart[0] + impactdist * dir[0];
1393         impactpoint[1] = linestart[1] + impactdist * dir[1];
1394         impactpoint[2] = linestart[2] + impactdist * dir[2];
1395         // calculate impactnormal (surface normal at point of impact)
1396         impactnormal[0] = impactpoint[0] - sphereorigin[0];
1397         impactnormal[1] = impactpoint[1] - sphereorigin[1];
1398         impactnormal[2] = impactpoint[2] - sphereorigin[2];
1399         // normalize impactnormal
1400         scale = impactnormal[0] * impactnormal[0] + impactnormal[1] * impactnormal[1] + impactnormal[2] * impactnormal[2];
1401         if (scale)
1402         {
1403                 scale = 1.0 / sqrt(scale);
1404                 impactnormal[0] *= scale;
1405                 impactnormal[1] *= scale;
1406                 impactnormal[2] *= scale;
1407         }
1408         // return fraction of movement distance
1409         return impactdist / linelength;
1410 }
1411
1412 void Collision_TraceLineTriangleFloat(trace_t *trace, const vec3_t linestart, const vec3_t lineend, const float *point0, const float *point1, const float *point2)
1413 {
1414         float d1, d2, d, f, fnudged, impact[3], edgenormal[3], faceplanenormal[3], faceplanedist, edge[3];
1415
1416         // this code is designed for clockwise triangles, conversion to
1417         // counterclockwise would require swapping some things around...
1418         // it is easier to simply swap the point0 and point2 parameters to this
1419         // function when calling it than it is to rewire the internals.
1420
1421         // calculate the faceplanenormal of the triangle, this represents the front side
1422         TriangleNormal(point0, point1, point2, faceplanenormal);
1423         // there's no point in processing a degenerate triangle (GIGO - Garbage In, Garbage Out)
1424         if (DotProduct(faceplanenormal, faceplanenormal) < 0.0001f)
1425                 return;
1426         // normalize the normal
1427         VectorNormalize(faceplanenormal);
1428         // calculate the distance
1429         faceplanedist = DotProduct(point0, faceplanenormal);
1430
1431         // calculate the start distance
1432         d1 = DotProduct(faceplanenormal, linestart) - faceplanedist;
1433         // if start point is on the back side there is no collision
1434         // (we don't care about traces going through the triangle the wrong way)
1435         if (d1 < 0)
1436                 return;
1437
1438         // calculate the end distance
1439         d2 = DotProduct(faceplanenormal, lineend) - faceplanedist;
1440         // if both are in front, there is no collision
1441         if (d2 >= 0)
1442                 return;
1443
1444         // from here on we know d1 is >= 0 and d2 is < 0
1445         // this means the line starts infront and ends behind, passing through it
1446
1447         // calculate the recipricol of the distance delta,
1448         // so we can use it multiple times cheaply (instead of division)
1449         d = 1.0f / (d1 - d2);
1450         // calculate the impact fraction by taking the start distance (> 0)
1451         // and subtracting the face plane distance (this is the distance of the
1452         // triangle along that same normal)
1453         // then multiply by the recipricol distance delta
1454         f = d1 * d;
1455         // skip out if this impact is further away than previous ones
1456         if (f > trace->realfraction)
1457                 return;
1458         // calculate the perfect impact point for classification of insidedness
1459         impact[0] = linestart[0] + f * (lineend[0] - linestart[0]);
1460         impact[1] = linestart[1] + f * (lineend[1] - linestart[1]);
1461         impact[2] = linestart[2] + f * (lineend[2] - linestart[2]);
1462
1463         // calculate the edge normal and reject if impact is outside triangle
1464         // (an edge normal faces away from the triangle, to get the desired normal
1465         //  a crossproduct with the faceplanenormal is used, and because of the way
1466         // the insidedness comparison is written it does not need to be normalized)
1467
1468         VectorSubtract(point2, point0, edge);
1469         CrossProduct(edge, faceplanenormal, edgenormal);
1470         if (DotProduct(impact, edgenormal) > DotProduct(point0, edgenormal))
1471                 return;
1472
1473         VectorSubtract(point0, point1, edge);
1474         CrossProduct(edge, faceplanenormal, edgenormal);
1475         if (DotProduct(impact, edgenormal) > DotProduct(point1, edgenormal))
1476                 return;
1477
1478         VectorSubtract(point1, point2, edge);
1479         CrossProduct(edge, faceplanenormal, edgenormal);
1480         if (DotProduct(impact, edgenormal) > DotProduct(point2, edgenormal))
1481                 return;
1482
1483         // store the new trace fraction
1484         trace->realfraction = bound(0, f, 1);
1485
1486         // calculate a nudged fraction to keep it out of the surface
1487         // (the main fraction remains perfect)
1488         fnudged = (d1 - collision_impactnudge.value) * d;
1489         trace->fraction = bound(0, fnudged, 1);
1490
1491         // store the new trace endpos
1492         // not needed, it's calculated later when the trace is finished
1493         //trace->endpos[0] = linestart[0] + fnudged * (lineend[0] - linestart[0]);
1494         //trace->endpos[1] = linestart[1] + fnudged * (lineend[1] - linestart[1]);
1495         //trace->endpos[2] = linestart[2] + fnudged * (lineend[2] - linestart[2]);
1496
1497         // store the new trace plane (because collisions only happen from
1498         // the front this is always simply the triangle normal, never flipped)
1499         VectorCopy(faceplanenormal, trace->plane.normal);
1500         trace->plane.dist = faceplanedist;
1501 }
1502
1503 typedef struct colbspnode_s
1504 {
1505         mplane_t plane;
1506         struct colbspnode_s *children[2];
1507         // the node is reallocated or split if max is reached
1508         int numcolbrushf;
1509         int maxcolbrushf;
1510         colbrushf_t **colbrushflist;
1511         //int numcolbrushd;
1512         //int maxcolbrushd;
1513         //colbrushd_t **colbrushdlist;
1514 }
1515 colbspnode_t;
1516
1517 typedef struct colbsp_s
1518 {
1519         mempool_t *mempool;
1520         colbspnode_t *nodes;
1521 }
1522 colbsp_t;
1523
1524 colbsp_t *Collision_CreateCollisionBSP(mempool_t *mempool)
1525 {
1526         colbsp_t *bsp;
1527         bsp = Mem_Alloc(mempool, sizeof(colbsp_t));
1528         bsp->mempool = mempool;
1529         bsp->nodes = Mem_Alloc(bsp->mempool, sizeof(colbspnode_t));
1530         return bsp;
1531 }
1532
1533 void Collision_FreeCollisionBSPNode(colbspnode_t *node)
1534 {
1535         if (node->children[0])
1536                 Collision_FreeCollisionBSPNode(node->children[0]);
1537         if (node->children[1])
1538                 Collision_FreeCollisionBSPNode(node->children[1]);
1539         while (--node->numcolbrushf)
1540                 Mem_Free(node->colbrushflist[node->numcolbrushf]);
1541         //while (--node->numcolbrushd)
1542         //      Mem_Free(node->colbrushdlist[node->numcolbrushd]);
1543         Mem_Free(node);
1544 }
1545
1546 void Collision_FreeCollisionBSP(colbsp_t *bsp)
1547 {
1548         Collision_FreeCollisionBSPNode(bsp->nodes);
1549         Mem_Free(bsp);
1550 }
1551
1552 void Collision_BoundingBoxOfBrushTraceSegment(const colbrushf_t *start, const colbrushf_t *end, vec3_t mins, vec3_t maxs, float startfrac, float endfrac)
1553 {
1554         int i;
1555         colpointf_t *ps, *pe;
1556         float tempstart[3], tempend[3];
1557         VectorLerp(start->points[0].v, startfrac, end->points[0].v, mins);
1558         VectorCopy(mins, maxs);
1559         for (i = 0, ps = start->points, pe = end->points;i < start->numpoints;i++, ps++, pe++)
1560         {
1561                 VectorLerp(ps->v, startfrac, pe->v, tempstart);
1562                 VectorLerp(ps->v, endfrac, pe->v, tempend);
1563                 mins[0] = min(mins[0], min(tempstart[0], tempend[0]));
1564                 mins[1] = min(mins[1], min(tempstart[1], tempend[1]));
1565                 mins[2] = min(mins[2], min(tempstart[2], tempend[2]));
1566                 maxs[0] = min(maxs[0], min(tempstart[0], tempend[0]));
1567                 maxs[1] = min(maxs[1], min(tempstart[1], tempend[1]));
1568                 maxs[2] = min(maxs[2], min(tempstart[2], tempend[2]));
1569         }
1570         mins[0] -= 1;
1571         mins[1] -= 1;
1572         mins[2] -= 1;
1573         maxs[0] += 1;
1574         maxs[1] += 1;
1575         maxs[2] += 1;
1576 }
1577