collision.c

   1
   2 #include "quakedef.h"
   3 #include "polygon.h"
   4
   5 #define COLLISION_EDGEDIR_DOT_EPSILON (0.999f)
   6 #define COLLISION_EDGECROSS_MINLENGTH2 (1.0f / 4194304.0f)
   7 #define COLLISION_SNAPSCALE (32.0f)
   8 #define COLLISION_SNAP (1.0f / COLLISION_SNAPSCALE)
   9 #define COLLISION_SNAP2 (2.0f / COLLISION_SNAPSCALE)
  10 #define COLLISION_PLANE_DIST_EPSILON (2.0f / COLLISION_SNAPSCALE)
  11
  12 cvar_t collision_impactnudge = {0, "collision_impactnudge", "0.03125", "how much to back off from the impact"};
  13 cvar_t collision_startnudge = {0, "collision_startnudge", "0", "how much to bias collision trace start"};
  14 cvar_t collision_endnudge = {0, "collision_endnudge", "0", "how much to bias collision trace end"};
  15 cvar_t collision_enternudge = {0, "collision_enternudge", "0", "how much to bias collision entry fraction"};
  16 cvar_t collision_leavenudge = {0, "collision_leavenudge", "0", "how much to bias collision exit fraction"};
  17 cvar_t collision_prefernudgedfraction = {0, "collision_prefernudgedfraction", "1", "whether to sort collision events by nudged fraction (1) or real fraction (0)"};
  18 #ifdef COLLISION_STUPID_TRACE_ENDPOS_IN_SOLID_WORKAROUND
  19 cvar_t collision_endposnudge = {0, "collision_endposnudge", "0", "workaround to fix trace_endpos sometimes being returned where it would be inside solid by making that collision hit (recommended: values like 1)"};
  20 #endif
  21
  22 void Collision_Init (void)
  23 {
  24         Cvar_RegisterVariable(&collision_impactnudge);
  25         Cvar_RegisterVariable(&collision_startnudge);
  26         Cvar_RegisterVariable(&collision_endnudge);
  27         Cvar_RegisterVariable(&collision_enternudge);
  28         Cvar_RegisterVariable(&collision_leavenudge);
  29         Cvar_RegisterVariable(&collision_prefernudgedfraction);
  30 #ifdef COLLISION_STUPID_TRACE_ENDPOS_IN_SOLID_WORKAROUND
  31         Cvar_RegisterVariable(&collision_endposnudge);
  32 #endif
  33 }
  34
  35
  36
  37
  38
  39
  40
  41
  42
  43
  44
  45
  46
  47
  48 void Collision_PrintBrushAsQHull(colbrushf_t *brush, const char *name)
  49 {
  50         int i;
  51         Con_Printf("3 %s\n%i\n", name, brush->numpoints);
  52         for (i = 0;i < brush->numpoints;i++)
  53                 Con_Printf("%f %f %f\n", brush->points[i].v[0], brush->points[i].v[1], brush->points[i].v[2]);
  54         // FIXME: optimize!
  55         Con_Printf("4\n%i\n", brush->numplanes);
  56         for (i = 0;i < brush->numplanes;i++)
  57                 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);
  58 }
  59
  60 void Collision_ValidateBrush(colbrushf_t *brush)
  61 {
  62         int j, k, pointsoffplanes, pointonplanes, pointswithinsufficientplanes, printbrush;
  63         float d;
  64         printbrush = false;
  65         if (!brush->numpoints)
  66         {
  67                 Con_Print("Collision_ValidateBrush: brush with no points!\n");
  68                 printbrush = true;
  69         }
  70 #if 0
  71         // it's ok for a brush to have one point and no planes...
  72         if (brush->numplanes == 0 && brush->numpoints != 1)
  73         {
  74                 Con_Print("Collision_ValidateBrush: brush with no planes and more than one point!\n");
  75                 printbrush = true;
  76         }
  77 #endif
  78         if (brush->numplanes)
  79         {
  80                 pointsoffplanes = 0;
  81                 pointswithinsufficientplanes = 0;
  82                 for (k = 0;k < brush->numplanes;k++)
  83                         if (DotProduct(brush->planes[k].normal, brush->planes[k].normal) < 0.0001f)
  84                                 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);
  85                 for (j = 0;j < brush->numpoints;j++)
  86                 {
  87                         pointonplanes = 0;
  88                         for (k = 0;k < brush->numplanes;k++)
  89                         {
  90                                 d = DotProduct(brush->points[j].v, brush->planes[k].normal) - brush->planes[k].dist;
  91                                 if (d > COLLISION_PLANE_DIST_EPSILON)
  92                                 {
  93                                         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);
  94                                         printbrush = true;
  95                                 }
  96                                 if (fabs(d) > COLLISION_PLANE_DIST_EPSILON)
  97                                         pointsoffplanes++;
  98                                 else
  99                                         pointonplanes++;
 100                         }
 101                         if (pointonplanes < 3)
 102                                 pointswithinsufficientplanes++;
 103                 }
 104                 if (pointswithinsufficientplanes)
 105                 {
 106                         Con_Print("Collision_ValidateBrush: some points have insufficient planes, every point must be on at least 3 planes to form a corner.\n");
 107                         printbrush = true;
 108                 }
 109                 if (pointsoffplanes == 0) // all points are on all planes
 110                 {
 111                         Con_Print("Collision_ValidateBrush: all points lie on all planes (degenerate, no brush volume!)\n");
 112                         printbrush = true;
 113                 }
 114         }
 115         if (printbrush)
 116                 Collision_PrintBrushAsQHull(brush, "unnamed");
 117 }
 118
 119 float nearestplanedist_float(const float *normal, const colpointf_t *points, int numpoints)
 120 {
 121         float dist, bestdist;
 122         if (!numpoints)
 123                 return 0;
 124         bestdist = DotProduct(points->v, normal);
 125         points++;
 126         while(--numpoints)
 127         {
 128                 dist = DotProduct(points->v, normal);
 129                 bestdist = min(bestdist, dist);
 130                 points++;
 131         }
 132         return bestdist;
 133 }
 134
 135 float furthestplanedist_float(const float *normal, const colpointf_t *points, int numpoints)
 136 {
 137         float dist, bestdist;
 138         if (!numpoints)
 139                 return 0;
 140         bestdist = DotProduct(points->v, normal);
 141         points++;
 142         while(--numpoints)
 143         {
 144                 dist = DotProduct(points->v, normal);
 145                 bestdist = max(bestdist, dist);
 146                 points++;
 147         }
 148         return bestdist;
 149 }
 150
 151 void Collision_CalcEdgeDirsForPolygonBrushFloat(colbrushf_t *brush)
 152 {
 153         int i, j;
 154         for (i = 0, j = brush->numpoints - 1;i < brush->numpoints;j = i, i++)
 155                 VectorSubtract(brush->points[i].v, brush->points[j].v, brush->edgedirs[j].v);
 156 }
 157
 158 colbrushf_t *Collision_NewBrushFromPlanes(mempool_t *mempool, int numoriginalplanes, const colplanef_t *originalplanes, int supercontents, int q3surfaceflags, texture_t *texture, int hasaabbplanes)
 159 {
 160         // TODO: planesbuf could be replaced by a remapping table
 161         int j, k, l, m, w, xyzflags;
 162         int numpointsbuf = 0, maxpointsbuf = 256, numedgedirsbuf = 0, maxedgedirsbuf = 256, numplanesbuf = 0, maxplanesbuf = 256, numelementsbuf = 0, maxelementsbuf = 256;
 163         int isaabb = true;
 164         double maxdist;
 165         colbrushf_t *brush;
 166         colpointf_t pointsbuf[256];
 167         colpointf_t edgedirsbuf[256];
 168         colplanef_t planesbuf[256];
 169         int elementsbuf[1024];
 170         int polypointbuf[256];
 171         int pmaxpoints = 64;
 172         int pnumpoints;
 173         double p[2][3*64];
 174 #if 0
 175         // enable these if debugging to avoid seeing garbage in unused data-
 176         memset(pointsbuf, 0, sizeof(pointsbuf));
 177         memset(edgedirsbuf, 0, sizeof(edgedirsbuf));
 178         memset(planesbuf, 0, sizeof(planesbuf));
 179         memset(elementsbuf, 0, sizeof(elementsbuf));
 180         memset(polypointbuf, 0, sizeof(polypointbuf));
 181         memset(p, 0, sizeof(p));
 182 #endif
 183
 184         // check if there are too many planes and skip the brush
 185         if (numoriginalplanes >= maxplanesbuf)
 186         {
 187                 Con_DPrint("Collision_NewBrushFromPlanes: failed to build collision brush: too many planes for buffer\n");
 188                 return NULL;
 189         }
 190
 191         // figure out how large a bounding box we need to properly compute this brush
 192         maxdist = 0;
 193         for (j = 0;j < numoriginalplanes;j++)
 194                 maxdist = max(maxdist, fabs(originalplanes[j].dist));
 195         // now make it large enough to enclose the entire brush, and round it off to a reasonable multiple of 1024
 196         maxdist = floor(maxdist * (4.0 / 1024.0) + 2) * 1024.0;
 197         // construct a collision brush (points, planes, and renderable mesh) from
 198         // a set of planes, this also optimizes out any unnecessary planes (ones
 199         // whose polygon is clipped away by the other planes)
 200         for (j = 0;j < numoriginalplanes;j++)
 201         {
 202                 // add the new plane
 203                 VectorCopy(originalplanes[j].normal, planesbuf[numplanesbuf].normal);
 204                 planesbuf[numplanesbuf].dist = originalplanes[j].dist;
 205                 planesbuf[numplanesbuf].q3surfaceflags = originalplanes[j].q3surfaceflags;
 206                 planesbuf[numplanesbuf].texture = originalplanes[j].texture;
 207                 numplanesbuf++;
 208
 209                 // create a large polygon from the plane
 210                 w = 0;
 211                 PolygonD_QuadForPlane(p[w], originalplanes[j].normal[0], originalplanes[j].normal[1], originalplanes[j].normal[2], originalplanes[j].dist, maxdist);
 212                 pnumpoints = 4;
 213                 // clip it by all other planes
 214                 for (k = 0;k < numoriginalplanes && pnumpoints >= 3 && pnumpoints <= pmaxpoints;k++)
 215                 {
 216                         // skip the plane this polygon
 217                         // (nothing happens if it is processed, this is just an optimization)
 218                         if (k != j)
 219                         {
 220                                 // we want to keep the inside of the brush plane so we flip
 221                                 // the cutting plane
 222                                 PolygonD_Divide(pnumpoints, p[w], -originalplanes[k].normal[0], -originalplanes[k].normal[1], -originalplanes[k].normal[2], -originalplanes[k].dist, COLLISION_PLANE_DIST_EPSILON, pmaxpoints, p[!w], &pnumpoints, 0, NULL, NULL, NULL);
 223                                 w = !w;
 224                         }
 225                 }
 226
 227                 // if nothing is left, skip it
 228                 if (pnumpoints < 3)
 229                 {
 230                         //Con_DPrintf("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);
 231                         continue;
 232                 }
 233
 234                 for (k = 0;k < pnumpoints;k++)
 235                 {
 236                         int l, m;
 237                         m = 0;
 238                         for (l = 0;l < numoriginalplanes;l++)
 239                                 if (fabs(DotProduct(&p[w][k*3], originalplanes[l].normal) - originalplanes[l].dist) < COLLISION_PLANE_DIST_EPSILON)
 240                                         m++;
 241                         if (m < 3)
 242                                 break;
 243                 }
 244                 if (k < pnumpoints)
 245                 {
 246                         Con_DPrintf("Collision_NewBrushFromPlanes: warning: polygon point does not lie on at least 3 planes\n");
 247                         //return NULL;
 248                 }
 249
 250                 // check if there are too many polygon vertices for buffer
 251                 if (pnumpoints > pmaxpoints)
 252                 {
 253                         Con_DPrint("Collision_NewBrushFromPlanes: failed to build collision brush: too many points for buffer\n");
 254                         return NULL;
 255                 }
 256
 257                 // check if there are too many triangle elements for buffer
 258                 if (numelementsbuf + (pnumpoints - 2) * 3 > maxelementsbuf)
 259                 {
 260                         Con_DPrint("Collision_NewBrushFromPlanes: failed to build collision brush: too many triangle elements for buffer\n");
 261                         return NULL;
 262                 }
 263
 264                 // add the unique points for this polygon
 265                 for (k = 0;k < pnumpoints;k++)
 266                 {
 267                         float v[3];
 268                         // downgrade to float precision before comparing
 269                         VectorCopy(&p[w][k*3], v);
 270
 271                         // check if there is already a matching point (no duplicates)
 272                         for (m = 0;m < numpointsbuf;m++)
 273                                 if (VectorDistance2(v, pointsbuf[m].v) < COLLISION_SNAP2)
 274                                         break;
 275
 276                         // if there is no match, add a new one
 277                         if (m == numpointsbuf)
 278                         {
 279                                 // check if there are too many and skip the brush
 280                                 if (numpointsbuf >= maxpointsbuf)
 281                                 {
 282                                         Con_DPrint("Collision_NewBrushFromPlanes: failed to build collision brush: too many points for buffer\n");
 283                                         return NULL;
 284                                 }
 285                                 // add the new one
 286                                 VectorCopy(&p[w][k*3], pointsbuf[numpointsbuf].v);
 287                                 numpointsbuf++;
 288                         }
 289
 290                         // store the index into a buffer
 291                         polypointbuf[k] = m;
 292                 }
 293
 294                 // add the triangles for the polygon
 295                 // (this particular code makes a triangle fan)
 296                 for (k = 0;k < pnumpoints - 2;k++)
 297                 {
 298                         elementsbuf[numelementsbuf++] = polypointbuf[0];
 299                         elementsbuf[numelementsbuf++] = polypointbuf[k + 1];
 300                         elementsbuf[numelementsbuf++] = polypointbuf[k + 2];
 301                 }
 302
 303                 // add the unique edgedirs for this polygon
 304                 for (k = 0, l = pnumpoints-1;k < pnumpoints;l = k, k++)
 305                 {
 306                         float dir[3];
 307                         // downgrade to float precision before comparing
 308                         VectorSubtract(&p[w][k*3], &p[w][l*3], dir);
 309                         VectorNormalize(dir);
 310
 311                         // check if there is already a matching edgedir (no duplicates)
 312                         for (m = 0;m < numedgedirsbuf;m++)
 313                                 if (DotProduct(dir, edgedirsbuf[m].v) >= COLLISION_EDGEDIR_DOT_EPSILON)
 314                                         break;
 315                         // skip this if there is
 316                         if (m < numedgedirsbuf)
 317                                 continue;
 318
 319                         // try again with negated edgedir
 320                         VectorNegate(dir, dir);
 321                         // check if there is already a matching edgedir (no duplicates)
 322                         for (m = 0;m < numedgedirsbuf;m++)
 323                                 if (DotProduct(dir, edgedirsbuf[m].v) >= COLLISION_EDGEDIR_DOT_EPSILON)
 324                                         break;
 325                         // if there is no match, add a new one
 326                         if (m == numedgedirsbuf)
 327                         {
 328                                 // check if there are too many and skip the brush
 329                                 if (numedgedirsbuf >= maxedgedirsbuf)
 330                                 {
 331                                         Con_DPrint("Collision_NewBrushFromPlanes: failed to build collision brush: too many edgedirs for buffer\n");
 332                                         return NULL;
 333                                 }
 334                                 // add the new one
 335                                 VectorCopy(dir, edgedirsbuf[numedgedirsbuf].v);
 336                                 numedgedirsbuf++;
 337                         }
 338                 }
 339
 340                 // if any normal is not purely axial, it's not an axis-aligned box
 341                 if (isaabb && (originalplanes[j].normal[0] == 0) + (originalplanes[j].normal[1] == 0) + (originalplanes[j].normal[2] == 0) < 2)
 342                         isaabb = false;
 343         }
 344
 345         // if nothing is left, there's nothing to allocate
 346         if (numplanesbuf < 4)
 347         {
 348                 Con_DPrintf("Collision_NewBrushFromPlanes: failed to build collision brush: %i triangles, %i planes (input was %i planes), %i vertices\n", numelementsbuf / 3, numplanesbuf, numoriginalplanes, numpointsbuf);
 349                 return NULL;
 350         }
 351
 352         // if no triangles or points could be constructed, then this routine failed but the brush is not discarded
 353         if (numelementsbuf < 12 || numpointsbuf < 4)
 354                 Con_DPrintf("Collision_NewBrushFromPlanes: unable to rebuild triangles/points for collision brush: %i triangles, %i planes (input was %i planes), %i vertices\n", numelementsbuf / 3, numplanesbuf, numoriginalplanes, numpointsbuf);
 355
 356         // validate plane distances
 357         for (j = 0;j < numplanesbuf;j++)
 358         {
 359                 float d = furthestplanedist_float(planesbuf[j].normal, pointsbuf, numpointsbuf);
 360                 if (fabs(planesbuf[j].dist - d) > COLLISION_PLANE_DIST_EPSILON)
 361                         Con_DPrintf("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);
 362         }
 363
 364         // allocate the brush and copy to it
 365         brush = (colbrushf_t *)Mem_Alloc(mempool, sizeof(colbrushf_t) + sizeof(colpointf_t) * numpointsbuf + sizeof(colpointf_t) * numedgedirsbuf + sizeof(colplanef_t) * numplanesbuf + sizeof(int) * numelementsbuf);
 366         brush->isaabb = isaabb;
 367         brush->hasaabbplanes = hasaabbplanes;
 368         brush->supercontents = supercontents;
 369         brush->numplanes = numplanesbuf;
 370         brush->numedgedirs = numedgedirsbuf;
 371         brush->numpoints = numpointsbuf;
 372         brush->numtriangles = numelementsbuf / 3;
 373         brush->planes = (colplanef_t *)(brush + 1);
 374         brush->points = (colpointf_t *)(brush->planes + brush->numplanes);
 375         brush->edgedirs = (colpointf_t *)(brush->points + brush->numpoints);
 376         brush->elements = (int *)(brush->points + brush->numpoints);
 377         brush->q3surfaceflags = q3surfaceflags;
 378         brush->texture = texture;
 379         for (j = 0;j < brush->numpoints;j++)
 380         {
 381                 brush->points[j].v[0] = pointsbuf[j].v[0];
 382                 brush->points[j].v[1] = pointsbuf[j].v[1];
 383                 brush->points[j].v[2] = pointsbuf[j].v[2];
 384         }
 385         for (j = 0;j < brush->numedgedirs;j++)
 386         {
 387                 brush->edgedirs[j].v[0] = edgedirsbuf[j].v[0];
 388                 brush->edgedirs[j].v[1] = edgedirsbuf[j].v[1];
 389                 brush->edgedirs[j].v[2] = edgedirsbuf[j].v[2];
 390         }
 391         for (j = 0;j < brush->numplanes;j++)
 392         {
 393                 brush->planes[j].normal[0] = planesbuf[j].normal[0];
 394                 brush->planes[j].normal[1] = planesbuf[j].normal[1];
 395                 brush->planes[j].normal[2] = planesbuf[j].normal[2];
 396                 brush->planes[j].dist = planesbuf[j].dist;
 397                 brush->planes[j].q3surfaceflags = planesbuf[j].q3surfaceflags;
 398                 brush->planes[j].texture = planesbuf[j].texture;
 399         }
 400         for (j = 0;j < brush->numtriangles * 3;j++)
 401                 brush->elements[j] = elementsbuf[j];
 402
 403         xyzflags = 0;
 404         VectorClear(brush->mins);
 405         VectorClear(brush->maxs);
 406         for (j = 0;j < min(6, numoriginalplanes);j++)
 407         {
 408                      if (originalplanes[j].normal[0] ==  1) {xyzflags |=  1;brush->maxs[0] =  originalplanes[j].dist;}
 409                 else if (originalplanes[j].normal[0] == -1) {xyzflags |=  2;brush->mins[0] = -originalplanes[j].dist;}
 410                 else if (originalplanes[j].normal[1] ==  1) {xyzflags |=  4;brush->maxs[1] =  originalplanes[j].dist;}
 411                 else if (originalplanes[j].normal[1] == -1) {xyzflags |=  8;brush->mins[1] = -originalplanes[j].dist;}
 412                 else if (originalplanes[j].normal[2] ==  1) {xyzflags |= 16;brush->maxs[2] =  originalplanes[j].dist;}
 413                 else if (originalplanes[j].normal[2] == -1) {xyzflags |= 32;brush->mins[2] = -originalplanes[j].dist;}
 414         }
 415         // if not all xyzflags were set, then this is not a brush from q3map/q3map2, and needs reconstruction of the bounding box
 416         // (this case works for any brush with valid points, but sometimes brushes are not reconstructed properly and hence the points are not valid, so this is reserved as a fallback case)
 417         if (xyzflags != 63)
 418         {
 419                 VectorCopy(brush->points[0].v, brush->mins);
 420                 VectorCopy(brush->points[0].v, brush->maxs);
 421                 for (j = 1;j < brush->numpoints;j++)
 422                 {
 423                         brush->mins[0] = min(brush->mins[0], brush->points[j].v[0]);
 424                         brush->mins[1] = min(brush->mins[1], brush->points[j].v[1]);
 425                         brush->mins[2] = min(brush->mins[2], brush->points[j].v[2]);
 426                         brush->maxs[0] = max(brush->maxs[0], brush->points[j].v[0]);
 427                         brush->maxs[1] = max(brush->maxs[1], brush->points[j].v[1]);
 428                         brush->maxs[2] = max(brush->maxs[2], brush->points[j].v[2]);
 429                 }
 430         }
 431         brush->mins[0] -= 1;
 432         brush->mins[1] -= 1;
 433         brush->mins[2] -= 1;
 434         brush->maxs[0] += 1;
 435         brush->maxs[1] += 1;
 436         brush->maxs[2] += 1;
 437         Collision_ValidateBrush(brush);
 438         return brush;
 439 }
 440
 441
 442
 443 void Collision_CalcPlanesForPolygonBrushFloat(colbrushf_t *brush)
 444 {
 445         int i;
 446         float edge0[3], edge1[3], edge2[3], normal[3], dist, bestdist;
 447         colpointf_t *p, *p2;
 448
 449         // FIXME: these probably don't actually need to be normalized if the collision code does not care
 450         if (brush->numpoints == 3)
 451         {
 452                 // optimized triangle case
 453                 TriangleNormal(brush->points[0].v, brush->points[1].v, brush->points[2].v, brush->planes[0].normal);
 454                 if (DotProduct(brush->planes[0].normal, brush->planes[0].normal) < 0.0001f)
 455                 {
 456                         // there's no point in processing a degenerate triangle (GIGO - Garbage In, Garbage Out)
 457                         brush->numplanes = 0;
 458                         return;
 459                 }
 460                 else
 461                 {
 462                         brush->numplanes = 5;
 463                         brush->numedgedirs = 3;
 464                         VectorNormalize(brush->planes[0].normal);
 465                         brush->planes[0].dist = DotProduct(brush->points->v, brush->planes[0].normal);
 466                         VectorNegate(brush->planes[0].normal, brush->planes[1].normal);
 467                         brush->planes[1].dist = -brush->planes[0].dist;
 468                         VectorSubtract(brush->points[2].v, brush->points[0].v, edge0);
 469                         VectorSubtract(brush->points[0].v, brush->points[1].v, edge1);
 470                         VectorSubtract(brush->points[1].v, brush->points[2].v, edge2);
 471                         VectorCopy(edge0, brush->edgedirs[0].v);
 472                         VectorCopy(edge1, brush->edgedirs[1].v);
 473                         VectorCopy(edge2, brush->edgedirs[2].v);
 474 #if 1
 475                         {
 476                                 float projectionnormal[3], projectionedge0[3], projectionedge1[3], projectionedge2[3];
 477                                 int i, best;
 478                                 float dist, bestdist;
 479                                 bestdist = fabs(brush->planes[0].normal[0]);
 480                                 best = 0;
 481                                 for (i = 1;i < 3;i++)
 482                                 {
 483                                         dist = fabs(brush->planes[0].normal[i]);
 484                                         if (bestdist < dist)
 485                                         {
 486                                                 bestdist = dist;
 487                                                 best = i;
 488                                         }
 489                                 }
 490                                 VectorClear(projectionnormal);
 491                                 if (brush->planes[0].normal[best] < 0)
 492                                         projectionnormal[best] = -1;
 493                                 else
 494                                         projectionnormal[best] = 1;
 495                                 VectorCopy(edge0, projectionedge0);
 496                                 VectorCopy(edge1, projectionedge1);
 497                                 VectorCopy(edge2, projectionedge2);
 498                                 projectionedge0[best] = 0;
 499                                 projectionedge1[best] = 0;
 500                                 projectionedge2[best] = 0;
 501                                 CrossProduct(projectionedge0, projectionnormal, brush->planes[2].normal);
 502                                 CrossProduct(projectionedge1, projectionnormal, brush->planes[3].normal);
 503                                 CrossProduct(projectionedge2, projectionnormal, brush->planes[4].normal);
 504                         }
 505 #else
 506                         CrossProduct(edge0, brush->planes->normal, brush->planes[2].normal);
 507                         CrossProduct(edge1, brush->planes->normal, brush->planes[3].normal);
 508                         CrossProduct(edge2, brush->planes->normal, brush->planes[4].normal);
 509 #endif
 510                         VectorNormalize(brush->planes[2].normal);
 511                         VectorNormalize(brush->planes[3].normal);
 512                         VectorNormalize(brush->planes[4].normal);
 513                         brush->planes[2].dist = DotProduct(brush->points[2].v, brush->planes[2].normal);
 514                         brush->planes[3].dist = DotProduct(brush->points[0].v, brush->planes[3].normal);
 515                         brush->planes[4].dist = DotProduct(brush->points[1].v, brush->planes[4].normal);
 516
 517                         if (developer_extra.integer)
 518                         {
 519                                 // validation code
 520 #if 0
 521                                 float temp[3];
 522
 523                                 VectorSubtract(brush->points[0].v, brush->points[1].v, edge0);
 524                                 VectorSubtract(brush->points[2].v, brush->points[1].v, edge1);
 525                                 CrossProduct(edge0, edge1, normal);
 526                                 VectorNormalize(normal);
 527                                 VectorSubtract(normal, brush->planes[0].normal, temp);
 528                                 if (VectorLength(temp) > 0.01f)
 529                                         Con_DPrintf("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]);
 530                                 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)
 531                                         Con_DPrintf("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);
 532 #if 0
 533                                 if (fabs(DotProduct(brush->planes[2].normal, brush->planes[0].normal)) > 0.01f)
 534                                         Con_DPrintf("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);
 535                                 if (fabs(DotProduct(brush->planes[3].normal, brush->planes[0].normal)) > 0.01f)
 536                                         Con_DPrintf("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);
 537                                 if (fabs(DotProduct(brush->planes[4].normal, brush->planes[0].normal)) > 0.01f)
 538                                         Con_DPrintf("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);
 539                                 if (fabs(DotProduct(brush->planes[2].normal, edge0)) > 0.01f)
 540                                         Con_DPrintf("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]);
 541                                 if (fabs(DotProduct(brush->planes[3].normal, edge1)) > 0.01f)
 542                                         Con_DPrintf("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]);
 543                                 if (fabs(DotProduct(brush->planes[4].normal, edge2)) > 0.01f)
 544                                         Con_DPrintf("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]);
 545 #endif
 546 #endif
 547                                 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)
 548                                         Con_DPrintf("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);
 549                                 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)
 550                                         Con_DPrintf("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);
 551                                 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)
 552                                         Con_DPrintf("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);
 553                                 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)
 554                                         Con_DPrintf("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);
 555                                 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)
 556                                         Con_DPrintf("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);
 557                         }
 558                 }
 559         }
 560         else
 561         {
 562                 // choose best surface normal for polygon's plane
 563                 bestdist = 0;
 564                 for (i = 0, p = brush->points + 1;i < brush->numpoints - 2;i++, p++)
 565                 {
 566                         VectorSubtract(p[-1].v, p[0].v, edge0);
 567                         VectorSubtract(p[1].v, p[0].v, edge1);
 568                         CrossProduct(edge0, edge1, normal);
 569                         //TriangleNormal(p[-1].v, p[0].v, p[1].v, normal);
 570                         dist = DotProduct(normal, normal);
 571                         if (i == 0 || bestdist < dist)
 572                         {
 573                                 bestdist = dist;
 574                                 VectorCopy(normal, brush->planes->normal);
 575                         }
 576                 }
 577                 if (bestdist < 0.0001f)
 578                 {
 579                         // there's no point in processing a degenerate triangle (GIGO - Garbage In, Garbage Out)
 580                         brush->numplanes = 0;
 581                         return;
 582                 }
 583                 else
 584                 {
 585                         brush->numplanes = brush->numpoints + 2;
 586                         VectorNormalize(brush->planes->normal);
 587                         brush->planes->dist = DotProduct(brush->points->v, brush->planes->normal);
 588
 589                         // negate plane to create other side
 590                         VectorNegate(brush->planes[0].normal, brush->planes[1].normal);
 591                         brush->planes[1].dist = -brush->planes[0].dist;
 592                         for (i = 0, p = brush->points + (brush->numpoints - 1), p2 = brush->points;i < brush->numpoints;i++, p = p2, p2++)
 593                         {
 594                                 VectorSubtract(p->v, p2->v, edge0);
 595                                 CrossProduct(edge0, brush->planes->normal, brush->planes[i + 2].normal);
 596                                 VectorNormalize(brush->planes[i + 2].normal);
 597                                 brush->planes[i + 2].dist = DotProduct(p->v, brush->planes[i + 2].normal);
 598                         }
 599                 }
 600         }
 601
 602         if (developer_extra.integer)
 603         {
 604                 // validity check - will be disabled later
 605                 Collision_ValidateBrush(brush);
 606                 for (i = 0;i < brush->numplanes;i++)
 607                 {
 608                         int j;
 609                         for (j = 0, p = brush->points;j < brush->numpoints;j++, p++)
 610                                 if (DotProduct(p->v, brush->planes[i].normal) > brush->planes[i].dist + COLLISION_PLANE_DIST_EPSILON)
 611                                         Con_DPrintf("Error in brush plane generation, plane %i\n", i);
 612                 }
 613         }
 614 }
 615
 616 colbrushf_t *Collision_AllocBrushFromPermanentPolygonFloat(mempool_t *mempool, int numpoints, float *points, int supercontents, int q3surfaceflags, texture_t *texture)
 617 {
 618         colbrushf_t *brush;
 619         brush = (colbrushf_t *)Mem_Alloc(mempool, sizeof(colbrushf_t) + sizeof(colplanef_t) * (numpoints + 2) + sizeof(colpointf_t) * numpoints);
 620         brush->isaabb = false;
 621         brush->hasaabbplanes = false;
 622         brush->supercontents = supercontents;
 623         brush->numpoints = numpoints;
 624         brush->numedgedirs = numpoints;
 625         brush->numplanes = numpoints + 2;
 626         brush->planes = (colplanef_t *)(brush + 1);
 627         brush->points = (colpointf_t *)points;
 628         brush->edgedirs = (colpointf_t *)(brush->planes + brush->numplanes);
 629         brush->q3surfaceflags = q3surfaceflags;
 630         brush->texture = texture;
 631         Sys_Error("Collision_AllocBrushFromPermanentPolygonFloat: FIXME: this code needs to be updated to generate a mesh...");
 632         return brush;
 633 }
 634
 635 // NOTE: start and end of each brush pair must have same numplanes/numpoints
 636 void Collision_TraceBrushBrushFloat(trace_t *trace, const colbrushf_t *trace_start, const colbrushf_t *trace_end, const colbrushf_t *other_start, const colbrushf_t *other_end)
 637 {
 638         int nplane, nplane2, nedge1, nedge2, hitq3surfaceflags = 0;
 639         int tracenumedgedirs = trace_start->numedgedirs;
 640         //int othernumedgedirs = other_start->numedgedirs;
 641         int tracenumpoints = trace_start->numpoints;
 642         int othernumpoints = other_start->numpoints;
 643         int numplanes1 = other_start->numplanes;
 644         int numplanes2 = numplanes1 + trace_start->numplanes;
 645         int numplanes3 = numplanes2 + trace_start->numedgedirs * other_start->numedgedirs * 2;
 646         vec_t enterfrac = -1, leavefrac = 1, startdist, enddist, ie, f, imove, enterfrac2 = -1;
 647         vec4_t startplane;
 648         vec4_t endplane;
 649         vec4_t newimpactplane;
 650         texture_t *hittexture = NULL;
 651         vec_t startdepth = 1;
 652         vec3_t startdepthnormal;
 653
 654         VectorClear(startdepthnormal);
 655         Vector4Clear(newimpactplane);
 656
 657         // fast case for AABB vs compiled brushes (which begin with AABB planes and also have precomputed bevels for AABB collisions)
 658         if (trace_start->isaabb && other_start->hasaabbplanes)
 659                 numplanes3 = numplanes2 = numplanes1;
 660
 661         // Separating Axis Theorem:
 662         // if a supporting vector (plane normal) can be found that separates two
 663         // objects, they are not colliding.
 664         //
 665         // Minkowski Sum:
 666         // reduce the size of one object to a point while enlarging the other to
 667         // represent the space that point can not occupy.
 668         //
 669         // try every plane we can construct between the two brushes and measure
 670         // the distance between them.
 671         for (nplane = 0;nplane < numplanes3;nplane++)
 672         {
 673                 if (nplane < numplanes1)
 674                 {
 675                         nplane2 = nplane;
 676                         VectorCopy(other_start->planes[nplane2].normal, startplane);
 677                         VectorCopy(other_end->planes[nplane2].normal, endplane);
 678                 }
 679                 else if (nplane < numplanes2)
 680                 {
 681                         nplane2 = nplane - numplanes1;
 682                         VectorCopy(trace_start->planes[nplane2].normal, startplane);
 683                         VectorCopy(trace_end->planes[nplane2].normal, endplane);
 684                 }
 685                 else
 686                 {
 687                         // pick an edgedir from each brush and cross them
 688                         nplane2 = nplane - numplanes2;
 689                         nedge1 = nplane2 >> 1;
 690                         nedge2 = nedge1 / tracenumedgedirs;
 691                         nedge1 -= nedge2 * tracenumedgedirs;
 692                         if (nplane2 & 1)
 693                         {
 694                                 CrossProduct(trace_start->edgedirs[nedge1].v, other_start->edgedirs[nedge2].v, startplane);
 695                                 if (VectorLength2(startplane) < COLLISION_EDGECROSS_MINLENGTH2)
 696                                         continue; // degenerate crossproduct
 697                                 CrossProduct(trace_end->edgedirs[nedge1].v, other_end->edgedirs[nedge2].v, endplane);
 698                                 if (VectorLength2(endplane) < COLLISION_EDGECROSS_MINLENGTH2)
 699                                         continue; // degenerate crossproduct
 700                         }
 701                         else
 702                         {
 703                                 CrossProduct(other_start->edgedirs[nedge2].v, trace_start->edgedirs[nedge1].v, startplane);
 704                                 if (VectorLength2(startplane) < COLLISION_EDGECROSS_MINLENGTH2)
 705                                         continue; // degenerate crossproduct
 706                                 CrossProduct(other_end->edgedirs[nedge2].v, trace_end->edgedirs[nedge1].v, endplane);
 707                                 if (VectorLength2(endplane) < COLLISION_EDGECROSS_MINLENGTH2)
 708                                         continue; // degenerate crossproduct
 709                         }
 710                         VectorNormalize(startplane);
 711                         VectorNormalize(endplane);
 712                 }
 713                 startplane[3] = furthestplanedist_float(startplane, other_start->points, othernumpoints);
 714                 endplane[3] = furthestplanedist_float(startplane, other_end->points, othernumpoints);
 715                 startdist = nearestplanedist_float(startplane, trace_start->points, tracenumpoints) - startplane[3] - collision_startnudge.value;
 716                 enddist = nearestplanedist_float(endplane, trace_end->points, tracenumpoints) - endplane[3] - collision_endnudge.value;
 717                 //Con_Printf("%c%i: startdist = %f, enddist = %f, startdist / (startdist - enddist) = %f\n", nplane2 != nplane ? 'b' : 'a', nplane2, startdist, enddist, startdist / (startdist - enddist));
 718
 719                 // aside from collisions, this is also used for error correction
 720                 if (startdist < collision_impactnudge.value && nplane < numplanes1 && (startdepth < startdist || startdepth == 1))
 721                 {
 722                         startdepth = startdist;
 723                         VectorCopy(startplane, startdepthnormal);
 724                 }
 725
 726                 if (startdist >= -collision_impactnudge.value && enddist >= startdist)
 727                         return;
 728                 if (startdist <= 0 && enddist <= 0)
 729                         continue;
 730                 if (startdist > enddist)
 731                 {
 732                         // moving into brush
 733                         if (enddist >= collision_enternudge.value)
 734                                 return;
 735                         if (startdist > 0)
 736                         {
 737                                 // enter
 738                                 imove = 1 / (startdist - enddist);
 739                                 f = (startdist - collision_enternudge.value) * imove;
 740                                 if (f < 0)
 741                                         f = 0;
 742                                 // check if this will reduce the collision time range
 743                                 if (enterfrac < f)
 744                                 {
 745                                         // reduced collision time range
 746                                         enterfrac = f;
 747                                         // if the collision time range is now empty, no collision
 748                                         if (enterfrac > leavefrac)
 749                                                 return;
 750                                         // if the collision would be further away than the trace's
 751                                         // existing collision data, we don't care about this
 752                                         // collision
 753                                         if (enterfrac > trace->realfraction)
 754                                                 return;
 755                                         // calculate the nudged fraction and impact normal we'll
 756                                         // need if we accept this collision later
 757                                         enterfrac2 = (startdist - collision_impactnudge.value) * imove;
 758                                         ie = 1.0f - enterfrac;
 759                                         newimpactplane[0] = startplane[0] * ie + endplane[0] * enterfrac;
 760                                         newimpactplane[1] = startplane[1] * ie + endplane[1] * enterfrac;
 761                                         newimpactplane[2] = startplane[2] * ie + endplane[2] * enterfrac;
 762                                         newimpactplane[3] = startplane[3] * ie + endplane[3] * enterfrac;
 763                                         if (nplane < numplanes1)
 764                                         {
 765                                                 // use the plane from other
 766                                                 nplane2 = nplane;
 767                                                 hitq3surfaceflags = other_start->planes[nplane2].q3surfaceflags;
 768                                                 hittexture = other_start->planes[nplane2].texture;
 769                                         }
 770                                         else if (nplane < numplanes2)
 771                                         {
 772                                                 // use the plane from trace
 773                                                 nplane2 = nplane - numplanes1;
 774                                                 hitq3surfaceflags = trace_start->planes[nplane2].q3surfaceflags;
 775                                                 hittexture = trace_start->planes[nplane2].texture;
 776                                         }
 777                                         else
 778                                         {
 779                                                 hitq3surfaceflags = other_start->q3surfaceflags;
 780                                                 hittexture = other_start->texture;
 781                                         }
 782                                 }
 783                         }
 784                 }
 785                 else
 786                 {
 787                         // moving out of brush
 788                         if (startdist > 0)
 789                                 return;
 790                         if (enddist > 0)
 791                         {
 792                                 // leave
 793                                 f = (startdist + collision_leavenudge.value) / (startdist - enddist);
 794                                 if (f > 1)
 795                                         f = 1;
 796                                 // check if this will reduce the collision time range
 797                                 if (leavefrac > f)
 798                                 {
 799                                         // reduced collision time range
 800                                         leavefrac = f;
 801                                         // if the collision time range is now empty, no collision
 802                                         if (enterfrac > leavefrac)
 803                                                 return;
 804                                 }
 805                         }
 806                 }
 807         }
 808
 809         // at this point we know the trace overlaps the brush because it was not
 810         // rejected at any point in the loop above
 811
 812         // see if the trace started outside the brush or not
 813         if (enterfrac > -1)
 814         {
 815                 // started outside, and overlaps, therefore there is a collision here
 816                 // store out the impact information
 817                 if (trace->hitsupercontentsmask & other_start->supercontents)
 818                 {
 819                         trace->hitsupercontents = other_start->supercontents;
 820                         trace->hitq3surfaceflags = hitq3surfaceflags;
 821                         trace->hittexture = hittexture;
 822                         trace->realfraction = bound(0, enterfrac, 1);
 823                         trace->fraction = bound(0, enterfrac2, 1);
 824                         if (collision_prefernudgedfraction.integer)
 825                                 trace->realfraction = trace->fraction;
 826                         VectorCopy(newimpactplane, trace->plane.normal);
 827                         trace->plane.dist = newimpactplane[3];
 828                 }
 829         }
 830         else
 831         {
 832                 // started inside, update startsolid and friends
 833                 trace->startsupercontents |= other_start->supercontents;
 834                 if (trace->hitsupercontentsmask & other_start->supercontents)
 835                 {
 836                         trace->startsolid = true;
 837                         if (leavefrac < 1)
 838                                 trace->allsolid = true;
 839                         VectorCopy(newimpactplane, trace->plane.normal);
 840                         trace->plane.dist = newimpactplane[3];
 841                         if (trace->startdepth > startdepth)
 842                         {
 843                                 trace->startdepth = startdepth;
 844                                 VectorCopy(startdepthnormal, trace->startdepthnormal);
 845                         }
 846                 }
 847         }
 848 }
 849
 850 // NOTE: start and end of each brush pair must have same numplanes/numpoints
 851 void Collision_TraceLineBrushFloat(trace_t *trace, const vec3_t linestart, const vec3_t lineend, const colbrushf_t *other_start, const colbrushf_t *other_end)
 852 {
 853         int nplane, hitq3surfaceflags = 0;
 854         int numplanes = other_start->numplanes;
 855         vec_t enterfrac = -1, leavefrac = 1, startdist, enddist, ie, f, imove, enterfrac2 = -1;
 856         vec4_t startplane;
 857         vec4_t endplane;
 858         vec4_t newimpactplane;
 859         texture_t *hittexture = NULL;
 860         vec_t startdepth = 1;
 861         vec3_t startdepthnormal;
 862
 863         VectorClear(startdepthnormal);
 864         Vector4Clear(newimpactplane);
 865
 866         // Separating Axis Theorem:
 867         // if a supporting vector (plane normal) can be found that separates two
 868         // objects, they are not colliding.
 869         //
 870         // Minkowski Sum:
 871         // reduce the size of one object to a point while enlarging the other to
 872         // represent the space that point can not occupy.
 873         //
 874         // try every plane we can construct between the two brushes and measure
 875         // the distance between them.
 876         for (nplane = 0;nplane < numplanes;nplane++)
 877         {
 878                 VectorCopy(other_start->planes[nplane].normal, startplane);
 879                 startplane[3] = other_start->planes[nplane].dist;
 880                 VectorCopy(other_end->planes[nplane].normal, endplane);
 881                 endplane[3] = other_end->planes[nplane].dist;
 882                 startdist = DotProduct(linestart, startplane) - startplane[3] - collision_startnudge.value;
 883                 enddist = DotProduct(lineend, endplane) - endplane[3] - collision_endnudge.value;
 884                 //Con_Printf("%c%i: startdist = %f, enddist = %f, startdist / (startdist - enddist) = %f\n", nplane2 != nplane ? 'b' : 'a', nplane2, startdist, enddist, startdist / (startdist - enddist));
 885
 886                 // aside from collisions, this is also used for error correction
 887                 if (startdist < collision_impactnudge.value && (startdepth < startdist || startdepth == 1))
 888                 {
 889                         startdepth = startdist;
 890                         VectorCopy(startplane, startdepthnormal);
 891                 }
 892
 893                 if (startdist >= -collision_impactnudge.value && enddist >= startdist)
 894                         return;
 895                 if (startdist <= 0 && enddist <= 0)
 896                         continue;
 897                 if (startdist > enddist)
 898                 {
 899                         // moving into brush
 900                         if (enddist >= collision_enternudge.value)
 901                                 return;
 902                         if (startdist > 0)
 903                         {
 904                                 // enter
 905                                 imove = 1 / (startdist - enddist);
 906                                 f = (startdist - collision_enternudge.value) * imove;
 907                                 if (f < 0)
 908                                         f = 0;
 909                                 // check if this will reduce the collision time range
 910                                 if (enterfrac < f)
 911                                 {
 912                                         // reduced collision time range
 913                                         enterfrac = f;
 914                                         // if the collision time range is now empty, no collision
 915                                         if (enterfrac > leavefrac)
 916                                                 return;
 917                                         // if the collision would be further away than the trace's
 918                                         // existing collision data, we don't care about this
 919                                         // collision
 920                                         if (enterfrac > trace->realfraction)
 921                                                 return;
 922                                         // calculate the nudged fraction and impact normal we'll
 923                                         // need if we accept this collision later
 924                                         enterfrac2 = (startdist - collision_impactnudge.value) * imove;
 925                                         ie = 1.0f - enterfrac;
 926                                         newimpactplane[0] = startplane[0] * ie + endplane[0] * enterfrac;
 927                                         newimpactplane[1] = startplane[1] * ie + endplane[1] * enterfrac;
 928                                         newimpactplane[2] = startplane[2] * ie + endplane[2] * enterfrac;
 929                                         newimpactplane[3] = startplane[3] * ie + endplane[3] * enterfrac;
 930                                         hitq3surfaceflags = other_start->planes[nplane].q3surfaceflags;
 931                                         hittexture = other_start->planes[nplane].texture;
 932                                 }
 933                         }
 934                 }
 935                 else
 936                 {
 937                         // moving out of brush
 938                         if (startdist > 0)
 939                                 return;
 940                         if (enddist > 0)
 941                         {
 942                                 // leave
 943                                 f = (startdist + collision_leavenudge.value) / (startdist - enddist);
 944                                 if (f > 1)
 945                                         f = 1;
 946                                 // check if this will reduce the collision time range
 947                                 if (leavefrac > f)
 948                                 {
 949                                         // reduced collision time range
 950                                         leavefrac = f;
 951                                         // if the collision time range is now empty, no collision
 952                                         if (enterfrac > leavefrac)
 953                                                 return;
 954                                 }
 955                         }
 956                 }
 957         }
 958
 959         // at this point we know the trace overlaps the brush because it was not
 960         // rejected at any point in the loop above
 961
 962         // see if the trace started outside the brush or not
 963         if (enterfrac > -1)
 964         {
 965                 // started outside, and overlaps, therefore there is a collision here
 966                 // store out the impact information
 967                 if (trace->hitsupercontentsmask & other_start->supercontents)
 968                 {
 969                         trace->hitsupercontents = other_start->supercontents;
 970                         trace->hitq3surfaceflags = hitq3surfaceflags;
 971                         trace->hittexture = hittexture;
 972                         trace->realfraction = bound(0, enterfrac, 1);
 973                         trace->fraction = bound(0, enterfrac2, 1);
 974                         if (collision_prefernudgedfraction.integer)
 975                                 trace->realfraction = trace->fraction;
 976                         VectorCopy(newimpactplane, trace->plane.normal);
 977                         trace->plane.dist = newimpactplane[3];
 978                 }
 979         }
 980         else
 981         {
 982                 // started inside, update startsolid and friends
 983                 trace->startsupercontents |= other_start->supercontents;
 984                 if (trace->hitsupercontentsmask & other_start->supercontents)
 985                 {
 986                         trace->startsolid = true;
 987                         if (leavefrac < 1)
 988                                 trace->allsolid = true;
 989                         VectorCopy(newimpactplane, trace->plane.normal);
 990                         trace->plane.dist = newimpactplane[3];
 991                         if (trace->startdepth > startdepth)
 992                         {
 993                                 trace->startdepth = startdepth;
 994                                 VectorCopy(startdepthnormal, trace->startdepthnormal);
 995                         }
 996                 }
 997         }
 998 }
 999
1000 qboolean Collision_PointInsideBrushFloat(const vec3_t point, const colbrushf_t *brush)
1001 {
1002         int nplane;
1003         const colplanef_t *plane;
1004
1005         if (!BoxesOverlap(point, point, brush->mins, brush->maxs))
1006                 return false;
1007         for (nplane = 0, plane = brush->planes;nplane < brush->numplanes;nplane++, plane++)
1008                 if (DotProduct(plane->normal, point) > plane->dist)
1009                         return false;
1010         return true;
1011 }
1012
1013 void Collision_TracePointBrushFloat(trace_t *trace, const vec3_t point, const colbrushf_t *thatbrush)
1014 {
1015         if (!Collision_PointInsideBrushFloat(point, thatbrush))
1016                 return;
1017
1018         trace->startsupercontents |= thatbrush->supercontents;
1019         if (trace->hitsupercontentsmask & thatbrush->supercontents)
1020         {
1021                 trace->startsolid = true;
1022                 trace->allsolid = true;
1023         }
1024 }
1025
1026 void Collision_SnapCopyPoints(int numpoints, const colpointf_t *in, colpointf_t *out, float fractionprecision, float invfractionprecision)
1027 {
1028         int i;
1029         for (i = 0;i < numpoints;i++)
1030         {
1031                 out[i].v[0] = floor(in[i].v[0] * fractionprecision + 0.5f) * invfractionprecision;
1032                 out[i].v[1] = floor(in[i].v[1] * fractionprecision + 0.5f) * invfractionprecision;
1033                 out[i].v[2] = floor(in[i].v[2] * fractionprecision + 0.5f) * invfractionprecision;
1034         }
1035 }
1036
1037 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 stride, float *bbox6f, int supercontents, int q3surfaceflags, texture_t *texture, const vec3_t segmentmins, const vec3_t segmentmaxs)
1038 {
1039         int i;
1040         colpointf_t points[3];
1041         colpointf_t edgedirs[3];
1042         colplanef_t planes[5];
1043         colbrushf_t brush;
1044         memset(&brush, 0, sizeof(brush));
1045         brush.isaabb = false;
1046         brush.hasaabbplanes = false;
1047         brush.numpoints = 3;
1048         brush.numedgedirs = 3;
1049         brush.numplanes = 5;
1050         brush.points = points;
1051         brush.edgedirs = edgedirs;
1052         brush.planes = planes;
1053         brush.supercontents = supercontents;
1054         brush.q3surfaceflags = q3surfaceflags;
1055         brush.texture = texture;
1056         for (i = 0;i < brush.numplanes;i++)
1057         {
1058                 brush.planes[i].q3surfaceflags = q3surfaceflags;
1059                 brush.planes[i].texture = texture;
1060         }
1061         if(stride > 0)
1062         {
1063                 int k, cnt, tri;
1064                 cnt = (numtriangles + stride - 1) / stride;
1065                 for(i = 0; i < cnt; ++i)
1066                 {
1067                         if(BoxesOverlap(bbox6f + i * 6, bbox6f + i * 6 + 3, segmentmins, segmentmaxs))
1068                         {
1069                                 for(k = 0; k < stride; ++k)
1070                                 {
1071                                         tri = i * stride + k;
1072                                         if(tri >= numtriangles)
1073                                                 break;
1074                                         VectorCopy(vertex3f + element3i[tri * 3 + 0] * 3, points[0].v);
1075                                         VectorCopy(vertex3f + element3i[tri * 3 + 1] * 3, points[1].v);
1076                                         VectorCopy(vertex3f + element3i[tri * 3 + 2] * 3, points[2].v);
1077                                         Collision_SnapCopyPoints(brush.numpoints, points, points, COLLISION_SNAPSCALE, COLLISION_SNAP);
1078                                         Collision_CalcEdgeDirsForPolygonBrushFloat(&brush);
1079                                         Collision_CalcPlanesForPolygonBrushFloat(&brush);
1080                                         //Collision_PrintBrushAsQHull(&brush, "brush");
1081                                         Collision_TraceBrushBrushFloat(trace, thisbrush_start, thisbrush_end, &brush, &brush);
1082                                 }
1083                         }
1084                 }
1085         }
1086         else if(stride == 0)
1087         {
1088                 for (i = 0;i < numtriangles;i++, element3i += 3)
1089                 {
1090                         if (TriangleOverlapsBox(vertex3f + element3i[0]*3, vertex3f + element3i[1]*3, vertex3f + element3i[2]*3, segmentmins, segmentmaxs))
1091                         {
1092                                 VectorCopy(vertex3f + element3i[0] * 3, points[0].v);
1093                                 VectorCopy(vertex3f + element3i[1] * 3, points[1].v);
1094                                 VectorCopy(vertex3f + element3i[2] * 3, points[2].v);
1095                                 Collision_SnapCopyPoints(brush.numpoints, points, points, COLLISION_SNAPSCALE, COLLISION_SNAP);
1096                                 Collision_CalcEdgeDirsForPolygonBrushFloat(&brush);
1097                                 Collision_CalcPlanesForPolygonBrushFloat(&brush);
1098                                 //Collision_PrintBrushAsQHull(&brush, "brush");
1099                                 Collision_TraceBrushBrushFloat(trace, thisbrush_start, thisbrush_end, &brush, &brush);
1100                         }
1101                 }
1102         }
1103         else
1104         {
1105                 for (i = 0;i < numtriangles;i++, element3i += 3)
1106                 {
1107                         VectorCopy(vertex3f + element3i[0] * 3, points[0].v);
1108                         VectorCopy(vertex3f + element3i[1] * 3, points[1].v);
1109                         VectorCopy(vertex3f + element3i[2] * 3, points[2].v);
1110                         Collision_SnapCopyPoints(brush.numpoints, points, points, COLLISION_SNAPSCALE, COLLISION_SNAP);
1111                         Collision_CalcEdgeDirsForPolygonBrushFloat(&brush);
1112                         Collision_CalcPlanesForPolygonBrushFloat(&brush);
1113                         //Collision_PrintBrushAsQHull(&brush, "brush");
1114                         Collision_TraceBrushBrushFloat(trace, thisbrush_start, thisbrush_end, &brush, &brush);
1115                 }
1116         }
1117 }
1118
1119 void Collision_TraceLineTriangleMeshFloat(trace_t *trace, const vec3_t linestart, const vec3_t lineend, int numtriangles, const int *element3i, const float *vertex3f, int stride, float *bbox6f, int supercontents, int q3surfaceflags, texture_t *texture, const vec3_t segmentmins, const vec3_t segmentmaxs)
1120 {
1121         int i;
1122         // FIXME: snap vertices?
1123         if(stride > 0)
1124         {
1125                 int k, cnt, tri;
1126                 cnt = (numtriangles + stride - 1) / stride;
1127                 for(i = 0; i < cnt; ++i)
1128                 {
1129                         if(BoxesOverlap(bbox6f + i * 6, bbox6f + i * 6 + 3, segmentmins, segmentmaxs))
1130                         {
1131                                 for(k = 0; k < stride; ++k)
1132                                 {
1133                                         tri = i * stride + k;
1134                                         if(tri >= numtriangles)
1135                                                 break;
1136                                         Collision_TraceLineTriangleFloat(trace, linestart, lineend, vertex3f + element3i[tri * 3 + 0] * 3, vertex3f + element3i[tri * 3 + 1] * 3, vertex3f + element3i[tri * 3 + 2] * 3, supercontents, q3surfaceflags, texture);
1137                                 }
1138                         }
1139                 }
1140         }
1141         else
1142         {
1143                 for (i = 0;i < numtriangles;i++, element3i += 3)
1144                         Collision_TraceLineTriangleFloat(trace, linestart, lineend, vertex3f + element3i[0] * 3, vertex3f + element3i[1] * 3, vertex3f + element3i[2] * 3, supercontents, q3surfaceflags, texture);
1145         }
1146 }
1147
1148 void Collision_BrushForBox(colboxbrushf_t *boxbrush, const vec3_t mins, const vec3_t maxs, int supercontents, int q3surfaceflags, texture_t *texture)
1149 {
1150         int i;
1151         memset(boxbrush, 0, sizeof(*boxbrush));
1152         boxbrush->brush.isaabb = true;
1153         boxbrush->brush.hasaabbplanes = true;
1154         boxbrush->brush.points = boxbrush->points;
1155         boxbrush->brush.edgedirs = boxbrush->edgedirs;
1156         boxbrush->brush.planes = boxbrush->planes;
1157         boxbrush->brush.supercontents = supercontents;
1158         boxbrush->brush.q3surfaceflags = q3surfaceflags;
1159         boxbrush->brush.texture = texture;
1160         if (VectorCompare(mins, maxs))
1161         {
1162                 // point brush
1163                 boxbrush->brush.numpoints = 1;
1164                 boxbrush->brush.numedgedirs = 0;
1165                 boxbrush->brush.numplanes = 0;
1166                 VectorCopy(mins, boxbrush->brush.points[0].v);
1167         }
1168         else
1169         {
1170                 boxbrush->brush.numpoints = 8;
1171                 boxbrush->brush.numedgedirs = 3;
1172                 boxbrush->brush.numplanes = 6;
1173                 // there are 8 points on a box
1174                 // there are 3 edgedirs on a box (both signs are tested in collision)
1175                 // there are 6 planes on a box
1176                 VectorSet(boxbrush->brush.points[0].v, mins[0], mins[1], mins[2]);
1177                 VectorSet(boxbrush->brush.points[1].v, maxs[0], mins[1], mins[2]);
1178                 VectorSet(boxbrush->brush.points[2].v, mins[0], maxs[1], mins[2]);
1179                 VectorSet(boxbrush->brush.points[3].v, maxs[0], maxs[1], mins[2]);
1180                 VectorSet(boxbrush->brush.points[4].v, mins[0], mins[1], maxs[2]);
1181                 VectorSet(boxbrush->brush.points[5].v, maxs[0], mins[1], maxs[2]);
1182                 VectorSet(boxbrush->brush.points[6].v, mins[0], maxs[1], maxs[2]);
1183                 VectorSet(boxbrush->brush.points[7].v, maxs[0], maxs[1], maxs[2]);
1184                 VectorSet(boxbrush->brush.edgedirs[0].v, 1, 0, 0);
1185                 VectorSet(boxbrush->brush.edgedirs[1].v, 0, 1, 0);
1186                 VectorSet(boxbrush->brush.edgedirs[2].v, 0, 0, 1);
1187                 VectorSet(boxbrush->brush.planes[0].normal, -1,  0,  0);boxbrush->brush.planes[0].dist = -mins[0];
1188                 VectorSet(boxbrush->brush.planes[1].normal,  1,  0,  0);boxbrush->brush.planes[1].dist =  maxs[0];
1189                 VectorSet(boxbrush->brush.planes[2].normal,  0, -1,  0);boxbrush->brush.planes[2].dist = -mins[1];
1190                 VectorSet(boxbrush->brush.planes[3].normal,  0,  1,  0);boxbrush->brush.planes[3].dist =  maxs[1];
1191                 VectorSet(boxbrush->brush.planes[4].normal,  0,  0, -1);boxbrush->brush.planes[4].dist = -mins[2];
1192                 VectorSet(boxbrush->brush.planes[5].normal,  0,  0,  1);boxbrush->brush.planes[5].dist =  maxs[2];
1193                 for (i = 0;i < 6;i++)
1194                 {
1195                         boxbrush->brush.planes[i].q3surfaceflags = q3surfaceflags;
1196                         boxbrush->brush.planes[i].texture = texture;
1197                 }
1198         }
1199         boxbrush->brush.supercontents = supercontents;
1200         boxbrush->brush.q3surfaceflags = q3surfaceflags;
1201         boxbrush->brush.texture = texture;
1202         VectorSet(boxbrush->brush.mins, mins[0] - 1, mins[1] - 1, mins[2] - 1);
1203         VectorSet(boxbrush->brush.maxs, maxs[0] + 1, maxs[1] + 1, maxs[2] + 1);
1204         Collision_ValidateBrush(&boxbrush->brush);
1205 }
1206
1207 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, int supercontents, int q3surfaceflags, texture_t *texture)
1208 {
1209         colboxbrushf_t boxbrush, thisbrush_start, thisbrush_end;
1210         vec3_t startmins, startmaxs, endmins, endmaxs;
1211
1212         // create brushes for the collision
1213         VectorAdd(start, mins, startmins);
1214         VectorAdd(start, maxs, startmaxs);
1215         VectorAdd(end, mins, endmins);
1216         VectorAdd(end, maxs, endmaxs);
1217         Collision_BrushForBox(&boxbrush, cmins, cmaxs, supercontents, q3surfaceflags, texture);
1218         Collision_BrushForBox(&thisbrush_start, startmins, startmaxs, 0, 0, NULL);
1219         Collision_BrushForBox(&thisbrush_end, endmins, endmaxs, 0, 0, NULL);
1220
1221         memset(trace, 0, sizeof(trace_t));
1222         trace->hitsupercontentsmask = hitsupercontentsmask;
1223         trace->fraction = 1;
1224         trace->realfraction = 1;
1225         trace->allsolid = true;
1226         Collision_TraceBrushBrushFloat(trace, &thisbrush_start.brush, &thisbrush_end.brush, &boxbrush.brush, &boxbrush.brush);
1227 }
1228
1229 //pseudocode for detecting line/sphere overlap without calculating an impact point
1230 //linesphereorigin = sphereorigin - linestart;linediff = lineend - linestart;linespherefrac = DotProduct(linesphereorigin, linediff) / DotProduct(linediff, linediff);return VectorLength2(linesphereorigin - bound(0, linespherefrac, 1) * linediff) >= sphereradius*sphereradius;
1231
1232 // LordHavoc: currently unused, but tested
1233 // note: this can be used for tracing a moving sphere vs a stationary sphere,
1234 // by simply adding the moving sphere's radius to the sphereradius parameter,
1235 // all the results are correct (impactpoint, impactnormal, and fraction)
1236 float Collision_ClipTrace_Line_Sphere(double *linestart, double *lineend, double *sphereorigin, double sphereradius, double *impactpoint, double *impactnormal)
1237 {
1238         double dir[3], scale, v[3], deviationdist, impactdist, linelength;
1239         // make sure the impactpoint and impactnormal are valid even if there is
1240         // no collision
1241         VectorCopy(lineend, impactpoint);
1242         VectorClear(impactnormal);
1243         // calculate line direction
1244         VectorSubtract(lineend, linestart, dir);
1245         // normalize direction
1246         linelength = VectorLength(dir);
1247         if (linelength)
1248         {
1249                 scale = 1.0 / linelength;
1250                 VectorScale(dir, scale, dir);
1251         }
1252         // this dotproduct calculates the distance along the line at which the
1253         // sphere origin is (nearest point to the sphere origin on the line)
1254         impactdist = DotProduct(sphereorigin, dir) - DotProduct(linestart, dir);
1255         // calculate point on line at that distance, and subtract the
1256         // sphereorigin from it, so we have a vector to measure for the distance
1257         // of the line from the sphereorigin (deviation, how off-center it is)
1258         VectorMA(linestart, impactdist, dir, v);
1259         VectorSubtract(v, sphereorigin, v);
1260         deviationdist = VectorLength2(v);
1261         // if outside the radius, it's a miss for sure
1262         // (we do this comparison using squared radius to avoid a sqrt)
1263         if (deviationdist > sphereradius*sphereradius)
1264                 return 1; // miss (off to the side)
1265         // nudge back to find the correct impact distance
1266         impactdist -= sphereradius - deviationdist/sphereradius;
1267         if (impactdist >= linelength)
1268                 return 1; // miss (not close enough)
1269         if (impactdist < 0)
1270                 return 1; // miss (linestart is past or inside sphere)
1271         // calculate new impactpoint
1272         VectorMA(linestart, impactdist, dir, impactpoint);
1273         // calculate impactnormal (surface normal at point of impact)
1274         VectorSubtract(impactpoint, sphereorigin, impactnormal);
1275         // normalize impactnormal
1276         VectorNormalize(impactnormal);
1277         // return fraction of movement distance
1278         return impactdist / linelength;
1279 }
1280
1281 void Collision_TraceLineTriangleFloat(trace_t *trace, const vec3_t linestart, const vec3_t lineend, const float *point0, const float *point1, const float *point2, int supercontents, int q3surfaceflags, texture_t *texture)
1282 {
1283 #if 1
1284         // more optimized
1285         float d1, d2, d, f, impact[3], edgenormal[3], faceplanenormal[3], faceplanedist, faceplanenormallength2, edge01[3], edge21[3], edge02[3];
1286
1287         // this function executes:
1288         // 32 ops when line starts behind triangle
1289         // 38 ops when line ends infront of triangle
1290         // 43 ops when line fraction is already closer than this triangle
1291         // 72 ops when line is outside edge 01
1292         // 92 ops when line is outside edge 21
1293         // 115 ops when line is outside edge 02
1294         // 123 ops when line impacts triangle and updates trace results
1295
1296         // this code is designed for clockwise triangles, conversion to
1297         // counterclockwise would require swapping some things around...
1298         // it is easier to simply swap the point0 and point2 parameters to this
1299         // function when calling it than it is to rewire the internals.
1300
1301         // calculate the faceplanenormal of the triangle, this represents the front side
1302         // 15 ops
1303         VectorSubtract(point0, point1, edge01);
1304         VectorSubtract(point2, point1, edge21);
1305         CrossProduct(edge01, edge21, faceplanenormal);
1306         // there's no point in processing a degenerate triangle (GIGO - Garbage In, Garbage Out)
1307         // 6 ops
1308         faceplanenormallength2 = DotProduct(faceplanenormal, faceplanenormal);
1309         if (faceplanenormallength2 < 0.0001f)
1310                 return;
1311         // calculate the distance
1312         // 5 ops
1313         faceplanedist = DotProduct(point0, faceplanenormal);
1314
1315         // if start point is on the back side there is no collision
1316         // (we don't care about traces going through the triangle the wrong way)
1317
1318         // calculate the start distance
1319         // 6 ops
1320         d1 = DotProduct(faceplanenormal, linestart);
1321         if (d1 <= faceplanedist)
1322                 return;
1323
1324         // calculate the end distance
1325         // 6 ops
1326         d2 = DotProduct(faceplanenormal, lineend);
1327         // if both are in front, there is no collision
1328         if (d2 >= faceplanedist)
1329                 return;
1330
1331         // from here on we know d1 is >= 0 and d2 is < 0
1332         // this means the line starts infront and ends behind, passing through it
1333
1334         // calculate the recipricol of the distance delta,
1335         // so we can use it multiple times cheaply (instead of division)
1336         // 2 ops
1337         d = 1.0f / (d1 - d2);
1338         // calculate the impact fraction by taking the start distance (> 0)
1339         // and subtracting the face plane distance (this is the distance of the
1340         // triangle along that same normal)
1341         // then multiply by the recipricol distance delta
1342         // 2 ops
1343         f = (d1 - faceplanedist) * d;
1344         // skip out if this impact is further away than previous ones
1345         // 1 ops
1346         if (f > trace->realfraction)
1347                 return;
1348         // calculate the perfect impact point for classification of insidedness
1349         // 9 ops
1350         impact[0] = linestart[0] + f * (lineend[0] - linestart[0]);
1351         impact[1] = linestart[1] + f * (lineend[1] - linestart[1]);
1352         impact[2] = linestart[2] + f * (lineend[2] - linestart[2]);
1353
1354         // calculate the edge normal and reject if impact is outside triangle
1355         // (an edge normal faces away from the triangle, to get the desired normal
1356         //  a crossproduct with the faceplanenormal is used, and because of the way
1357         // the insidedness comparison is written it does not need to be normalized)
1358
1359         // first use the two edges from the triangle plane math
1360         // the other edge only gets calculated if the point survives that long
1361
1362         // 20 ops
1363         CrossProduct(edge01, faceplanenormal, edgenormal);
1364         if (DotProduct(impact, edgenormal) > DotProduct(point1, edgenormal))
1365                 return;
1366
1367         // 20 ops
1368         CrossProduct(faceplanenormal, edge21, edgenormal);
1369         if (DotProduct(impact, edgenormal) > DotProduct(point2, edgenormal))
1370                 return;
1371
1372         // 23 ops
1373         VectorSubtract(point0, point2, edge02);
1374         CrossProduct(faceplanenormal, edge02, edgenormal);
1375         if (DotProduct(impact, edgenormal) > DotProduct(point0, edgenormal))
1376                 return;
1377
1378         // 8 ops (rare)
1379
1380         // store the new trace fraction
1381         trace->realfraction = f;
1382
1383         // calculate a nudged fraction to keep it out of the surface
1384         // (the main fraction remains perfect)
1385         trace->fraction = f - collision_impactnudge.value * d;
1386
1387         if (collision_prefernudgedfraction.integer)
1388                 trace->realfraction = trace->fraction;
1389
1390         // store the new trace plane (because collisions only happen from
1391         // the front this is always simply the triangle normal, never flipped)
1392         d = 1.0 / sqrt(faceplanenormallength2);
1393         VectorScale(faceplanenormal, d, trace->plane.normal);
1394         trace->plane.dist = faceplanedist * d;
1395
1396         trace->hitsupercontents = supercontents;
1397         trace->hitq3surfaceflags = q3surfaceflags;
1398         trace->hittexture = texture;
1399 #else
1400         float d1, d2, d, f, fnudged, impact[3], edgenormal[3], faceplanenormal[3], faceplanedist, edge[3];
1401
1402         // this code is designed for clockwise triangles, conversion to
1403         // counterclockwise would require swapping some things around...
1404         // it is easier to simply swap the point0 and point2 parameters to this
1405         // function when calling it than it is to rewire the internals.
1406
1407         // calculate the unnormalized faceplanenormal of the triangle,
1408         // this represents the front side
1409         TriangleNormal(point0, point1, point2, faceplanenormal);
1410         // there's no point in processing a degenerate triangle
1411         // (GIGO - Garbage In, Garbage Out)
1412         if (DotProduct(faceplanenormal, faceplanenormal) < 0.0001f)
1413                 return;
1414         // calculate the unnormalized distance
1415         faceplanedist = DotProduct(point0, faceplanenormal);
1416
1417         // calculate the unnormalized start distance
1418         d1 = DotProduct(faceplanenormal, linestart) - faceplanedist;
1419         // if start point is on the back side there is no collision
1420         // (we don't care about traces going through the triangle the wrong way)
1421         if (d1 <= 0)
1422                 return;
1423
1424         // calculate the unnormalized end distance
1425         d2 = DotProduct(faceplanenormal, lineend) - faceplanedist;
1426         // if both are in front, there is no collision
1427         if (d2 >= 0)
1428                 return;
1429
1430         // from here on we know d1 is >= 0 and d2 is < 0
1431         // this means the line starts infront and ends behind, passing through it
1432
1433         // calculate the recipricol of the distance delta,
1434         // so we can use it multiple times cheaply (instead of division)
1435         d = 1.0f / (d1 - d2);
1436         // calculate the impact fraction by taking the start distance (> 0)
1437         // and subtracting the face plane distance (this is the distance of the
1438         // triangle along that same normal)
1439         // then multiply by the recipricol distance delta
1440         f = d1 * d;
1441         // skip out if this impact is further away than previous ones
1442         if (f > trace->realfraction)
1443                 return;
1444         // calculate the perfect impact point for classification of insidedness
1445         impact[0] = linestart[0] + f * (lineend[0] - linestart[0]);
1446         impact[1] = linestart[1] + f * (lineend[1] - linestart[1]);
1447         impact[2] = linestart[2] + f * (lineend[2] - linestart[2]);
1448
1449         // calculate the edge normal and reject if impact is outside triangle
1450         // (an edge normal faces away from the triangle, to get the desired normal
1451         //  a crossproduct with the faceplanenormal is used, and because of the way
1452         // the insidedness comparison is written it does not need to be normalized)
1453
1454         VectorSubtract(point2, point0, edge);
1455         CrossProduct(edge, faceplanenormal, edgenormal);
1456         if (DotProduct(impact, edgenormal) > DotProduct(point0, edgenormal))
1457                 return;
1458
1459         VectorSubtract(point0, point1, edge);
1460         CrossProduct(edge, faceplanenormal, edgenormal);
1461         if (DotProduct(impact, edgenormal) > DotProduct(point1, edgenormal))
1462                 return;
1463
1464         VectorSubtract(point1, point2, edge);
1465         CrossProduct(edge, faceplanenormal, edgenormal);
1466         if (DotProduct(impact, edgenormal) > DotProduct(point2, edgenormal))
1467                 return;
1468
1469         // store the new trace fraction
1470         trace->realfraction = bound(0, f, 1);
1471
1472         // store the new trace plane (because collisions only happen from
1473         // the front this is always simply the triangle normal, never flipped)
1474         VectorNormalize(faceplanenormal);
1475         VectorCopy(faceplanenormal, trace->plane.normal);
1476         trace->plane.dist = DotProduct(point0, faceplanenormal);
1477
1478         // calculate the normalized start and end distances
1479         d1 = DotProduct(trace->plane.normal, linestart) - trace->plane.dist;
1480         d2 = DotProduct(trace->plane.normal, lineend) - trace->plane.dist;
1481
1482         // calculate a nudged fraction to keep it out of the surface
1483         // (the main fraction remains perfect)
1484         fnudged = (d1 - collision_impactnudge.value) / (d1 - d2);
1485         trace->fraction = bound(0, fnudged, 1);
1486
1487         // store the new trace endpos
1488         // not needed, it's calculated later when the trace is finished
1489         //trace->endpos[0] = linestart[0] + fnudged * (lineend[0] - linestart[0]);
1490         //trace->endpos[1] = linestart[1] + fnudged * (lineend[1] - linestart[1]);
1491         //trace->endpos[2] = linestart[2] + fnudged * (lineend[2] - linestart[2]);
1492         trace->hitsupercontents = supercontents;
1493         trace->hitq3surfaceflags = q3surfaceflags;
1494         trace->hittexture = texture;
1495 #endif
1496 }
1497
1498 typedef struct colbspnode_s
1499 {
1500         mplane_t plane;
1501         struct colbspnode_s *children[2];
1502         // the node is reallocated or split if max is reached
1503         int numcolbrushf;
1504         int maxcolbrushf;
1505         colbrushf_t **colbrushflist;
1506         //int numcolbrushd;
1507         //int maxcolbrushd;
1508         //colbrushd_t **colbrushdlist;
1509 }
1510 colbspnode_t;
1511
1512 typedef struct colbsp_s
1513 {
1514         mempool_t *mempool;
1515         colbspnode_t *nodes;
1516 }
1517 colbsp_t;
1518
1519 colbsp_t *Collision_CreateCollisionBSP(mempool_t *mempool)
1520 {
1521         colbsp_t *bsp;
1522         bsp = (colbsp_t *)Mem_Alloc(mempool, sizeof(colbsp_t));
1523         bsp->mempool = mempool;
1524         bsp->nodes = (colbspnode_t *)Mem_Alloc(bsp->mempool, sizeof(colbspnode_t));
1525         return bsp;
1526 }
1527
1528 void Collision_FreeCollisionBSPNode(colbspnode_t *node)
1529 {
1530         if (node->children[0])
1531                 Collision_FreeCollisionBSPNode(node->children[0]);
1532         if (node->children[1])
1533                 Collision_FreeCollisionBSPNode(node->children[1]);
1534         while (--node->numcolbrushf)
1535                 Mem_Free(node->colbrushflist[node->numcolbrushf]);
1536         //while (--node->numcolbrushd)
1537         //      Mem_Free(node->colbrushdlist[node->numcolbrushd]);
1538         Mem_Free(node);
1539 }
1540
1541 void Collision_FreeCollisionBSP(colbsp_t *bsp)
1542 {
1543         Collision_FreeCollisionBSPNode(bsp->nodes);
1544         Mem_Free(bsp);
1545 }
1546
1547 void Collision_BoundingBoxOfBrushTraceSegment(const colbrushf_t *start, const colbrushf_t *end, vec3_t mins, vec3_t maxs, float startfrac, float endfrac)
1548 {
1549         int i;
1550         colpointf_t *ps, *pe;
1551         float tempstart[3], tempend[3];
1552         VectorLerp(start->points[0].v, startfrac, end->points[0].v, mins);
1553         VectorCopy(mins, maxs);
1554         for (i = 0, ps = start->points, pe = end->points;i < start->numpoints;i++, ps++, pe++)
1555         {
1556                 VectorLerp(ps->v, startfrac, pe->v, tempstart);
1557                 VectorLerp(ps->v, endfrac, pe->v, tempend);
1558                 mins[0] = min(mins[0], min(tempstart[0], tempend[0]));
1559                 mins[1] = min(mins[1], min(tempstart[1], tempend[1]));
1560                 mins[2] = min(mins[2], min(tempstart[2], tempend[2]));
1561                 maxs[0] = min(maxs[0], min(tempstart[0], tempend[0]));
1562                 maxs[1] = min(maxs[1], min(tempstart[1], tempend[1]));
1563                 maxs[2] = min(maxs[2], min(tempstart[2], tempend[2]));
1564         }
1565         mins[0] -= 1;
1566         mins[1] -= 1;
1567         mins[2] -= 1;
1568         maxs[0] += 1;
1569         maxs[1] += 1;
1570         maxs[2] += 1;
1571 }
1572
1573 //===========================================
1574
1575 void Collision_ClipToGenericEntity(trace_t *trace, dp_model_t *model, const frameblend_t *frameblend, const skeleton_t *skeleton, const vec3_t bodymins, const vec3_t bodymaxs, int bodysupercontents, matrix4x4_t *matrix, matrix4x4_t *inversematrix, const vec3_t start, const vec3_t mins, const vec3_t maxs, const vec3_t end, int hitsupercontentsmask)
1576 {
1577         float starttransformed[3], endtransformed[3];
1578
1579         memset(trace, 0, sizeof(*trace));
1580         trace->fraction = trace->realfraction = 1;
1581
1582         Matrix4x4_Transform(inversematrix, start, starttransformed);
1583         Matrix4x4_Transform(inversematrix, end, endtransformed);
1584 #if COLLISIONPARANOID >= 3
1585         Con_Printf("trans(%f %f %f -> %f %f %f, %f %f %f -> %f %f %f)", start[0], start[1], start[2], starttransformed[0], starttransformed[1], starttransformed[2], end[0], end[1], end[2], endtransformed[0], endtransformed[1], endtransformed[2]);
1586 #endif
1587
1588         if (model && model->TraceBox)
1589                 model->TraceBox(model, frameblend, skeleton, trace, starttransformed, mins, maxs, endtransformed, hitsupercontentsmask);
1590         else
1591                 Collision_ClipTrace_Box(trace, bodymins, bodymaxs, starttransformed, mins, maxs, endtransformed, hitsupercontentsmask, bodysupercontents, 0, NULL);
1592         trace->fraction = bound(0, trace->fraction, 1);
1593         trace->realfraction = bound(0, trace->realfraction, 1);
1594
1595         VectorLerp(start, trace->fraction, end, trace->endpos);
1596         // transform plane
1597         // NOTE: this relies on plane.dist being directly after plane.normal
1598         Matrix4x4_TransformPositivePlane(matrix, trace->plane.normal[0], trace->plane.normal[1], trace->plane.normal[2], trace->plane.dist, trace->plane.normal);
1599 }
1600
1601 void Collision_ClipToWorld(trace_t *trace, dp_model_t *model, const vec3_t start, const vec3_t mins, const vec3_t maxs, const vec3_t end, int hitsupercontents)
1602 {
1603         memset(trace, 0, sizeof(*trace));
1604         trace->fraction = trace->realfraction = 1;
1605         if (model && model->TraceBox)
1606                 model->TraceBox(model, NULL, NULL, trace, start, mins, maxs, end, hitsupercontents);
1607         trace->fraction = bound(0, trace->fraction, 1);
1608         trace->realfraction = bound(0, trace->realfraction, 1);
1609         VectorLerp(start, trace->fraction, end, trace->endpos);
1610 }
1611
1612 void Collision_ClipLineToGenericEntity(trace_t *trace, dp_model_t *model, const frameblend_t *frameblend, const skeleton_t *skeleton, const vec3_t bodymins, const vec3_t bodymaxs, int bodysupercontents, matrix4x4_t *matrix, matrix4x4_t *inversematrix, const vec3_t start, const vec3_t end, int hitsupercontentsmask)
1613 {
1614         float starttransformed[3], endtransformed[3];
1615
1616         memset(trace, 0, sizeof(*trace));
1617         trace->fraction = trace->realfraction = 1;
1618
1619         Matrix4x4_Transform(inversematrix, start, starttransformed);
1620         Matrix4x4_Transform(inversematrix, end, endtransformed);
1621 #if COLLISIONPARANOID >= 3
1622         Con_Printf("trans(%f %f %f -> %f %f %f, %f %f %f -> %f %f %f)", start[0], start[1], start[2], starttransformed[0], starttransformed[1], starttransformed[2], end[0], end[1], end[2], endtransformed[0], endtransformed[1], endtransformed[2]);
1623 #endif
1624
1625         if (model && model->TraceLine)
1626                 model->TraceLine(model, frameblend, skeleton, trace, starttransformed, endtransformed, hitsupercontentsmask);
1627         else
1628                 Collision_ClipTrace_Box(trace, bodymins, bodymaxs, starttransformed, vec3_origin, vec3_origin, endtransformed, hitsupercontentsmask, bodysupercontents, 0, NULL);
1629         trace->fraction = bound(0, trace->fraction, 1);
1630         trace->realfraction = bound(0, trace->realfraction, 1);
1631
1632         VectorLerp(start, trace->fraction, end, trace->endpos);
1633         // transform plane
1634         // NOTE: this relies on plane.dist being directly after plane.normal
1635         Matrix4x4_TransformPositivePlane(matrix, trace->plane.normal[0], trace->plane.normal[1], trace->plane.normal[2], trace->plane.dist, trace->plane.normal);
1636 }
1637
1638 void Collision_ClipLineToWorld(trace_t *trace, dp_model_t *model, const vec3_t start, const vec3_t end, int hitsupercontents)
1639 {
1640         memset(trace, 0, sizeof(*trace));
1641         trace->fraction = trace->realfraction = 1;
1642         if (model && model->TraceLine)
1643                 model->TraceLine(model, NULL, NULL, trace, start, end, hitsupercontents);
1644         trace->fraction = bound(0, trace->fraction, 1);
1645         trace->realfraction = bound(0, trace->realfraction, 1);
1646         VectorLerp(start, trace->fraction, end, trace->endpos);
1647 }
1648
1649 void Collision_ClipPointToGenericEntity(trace_t *trace, dp_model_t *model, const frameblend_t *frameblend, const skeleton_t *skeleton, const vec3_t bodymins, const vec3_t bodymaxs, int bodysupercontents, matrix4x4_t *matrix, matrix4x4_t *inversematrix, const vec3_t start, int hitsupercontentsmask)
1650 {
1651         float starttransformed[3];
1652
1653         memset(trace, 0, sizeof(*trace));
1654         trace->fraction = trace->realfraction = 1;
1655
1656         Matrix4x4_Transform(inversematrix, start, starttransformed);
1657 #if COLLISIONPARANOID >= 3
1658         Con_Printf("trans(%f %f %f -> %f %f %f)", start[0], start[1], start[2], starttransformed[0], starttransformed[1], starttransformed[2]);
1659 #endif
1660
1661         if (model && model->TracePoint)
1662                 model->TracePoint(model, NULL, NULL, trace, starttransformed, hitsupercontentsmask);
1663         else
1664                 Collision_ClipTrace_Point(trace, bodymins, bodymaxs, starttransformed, hitsupercontentsmask, bodysupercontents, 0, NULL);
1665
1666         VectorCopy(start, trace->endpos);
1667         // transform plane
1668         // NOTE: this relies on plane.dist being directly after plane.normal
1669         Matrix4x4_TransformPositivePlane(matrix, trace->plane.normal[0], trace->plane.normal[1], trace->plane.normal[2], trace->plane.dist, trace->plane.normal);
1670 }
1671
1672 void Collision_ClipPointToWorld(trace_t *trace, dp_model_t *model, const vec3_t start, int hitsupercontents)
1673 {
1674         memset(trace, 0, sizeof(*trace));
1675         trace->fraction = trace->realfraction = 1;
1676         if (model && model->TracePoint)
1677                 model->TracePoint(model, NULL, NULL, trace, start, hitsupercontents);
1678         VectorCopy(start, trace->endpos);
1679 }
1680
1681 void Collision_CombineTraces(trace_t *cliptrace, const trace_t *trace, void *touch, qboolean isbmodel)
1682 {
1683         // take the 'best' answers from the new trace and combine with existing data
1684         if (trace->allsolid)
1685                 cliptrace->allsolid = true;
1686         if (trace->startsolid)
1687         {
1688                 if (isbmodel)
1689                         cliptrace->bmodelstartsolid = true;
1690                 cliptrace->startsolid = true;
1691                 if (cliptrace->realfraction == 1)
1692                         cliptrace->ent = touch;
1693                 if (cliptrace->startdepth > trace->startdepth)
1694                 {
1695                         cliptrace->startdepth = trace->startdepth;
1696                         VectorCopy(trace->startdepthnormal, cliptrace->startdepthnormal);
1697                 }
1698         }
1699         // don't set this except on the world, because it can easily confuse
1700         // monsters underwater if there's a bmodel involved in the trace
1701         // (inopen && inwater is how they check water visibility)
1702         //if (trace->inopen)
1703         //      cliptrace->inopen = true;
1704         if (trace->inwater)
1705                 cliptrace->inwater = true;
1706         if ((trace->realfraction <= cliptrace->realfraction) && (VectorLength2(trace->plane.normal) > 0))
1707         {
1708                 cliptrace->fraction = trace->fraction;
1709                 cliptrace->realfraction = trace->realfraction;
1710                 VectorCopy(trace->endpos, cliptrace->endpos);
1711                 cliptrace->plane = trace->plane;
1712                 cliptrace->ent = touch;
1713                 cliptrace->hitsupercontents = trace->hitsupercontents;
1714                 cliptrace->hitq3surfaceflags = trace->hitq3surfaceflags;
1715                 cliptrace->hittexture = trace->hittexture;
1716         }
1717         cliptrace->startsupercontents |= trace->startsupercontents;
1718 }
1719
1720 void Collision_ShortenTrace(trace_t *trace, float shorten_factor, const vec3_t end)
1721 {
1722         // now undo our moving end 1 qu farther...
1723         trace->fraction = bound(trace->fraction, trace->fraction / shorten_factor - 1e-6, 1); // we subtract 1e-6 to guard for roundoff errors
1724         trace->realfraction = bound(trace->realfraction, trace->realfraction / shorten_factor - 1e-6, 1); // we subtract 1e-6 to guard for roundoff errors
1725         if(trace->fraction >= 1) // trace would NOT hit if not expanded!
1726         {
1727                 trace->fraction = 1;
1728                 trace->realfraction = 1;
1729                 VectorCopy(end, trace->endpos);
1730                 memset(&trace->plane, 0, sizeof(trace->plane));
1731                 trace->ent = NULL;
1732                 trace->hitsupercontentsmask = 0;
1733                 trace->hitsupercontents = 0;
1734                 trace->hitq3surfaceflags = 0;
1735                 trace->hittexture = NULL;
1736         }
1737 }