collision.c

   1
   2 #include "quakedef.h"
   3 #include "polygon.h"
   4
   5 #define COLLISION_SNAPSCALE (32.0f)
   6 #define COLLISION_SNAP (1.0f / COLLISION_SNAPSCALE)
   7 #define COLLISION_SNAP2 (2.0f / COLLISION_SNAPSCALE)
   8 #define COLLISION_PLANE_DIST_EPSILON (2.0f / COLLISION_SNAPSCALE)
   9
  10 cvar_t collision_impactnudge = {0, "collision_impactnudge", "0.03125", "how much to back off from the impact"};
  11 cvar_t collision_startnudge = {0, "collision_startnudge", "0", "how much to bias collision trace start"};
  12 cvar_t collision_endnudge = {0, "collision_endnudge", "0", "how much to bias collision trace end"};
  13 cvar_t collision_enternudge = {0, "collision_enternudge", "0", "how much to bias collision entry fraction"};
  14 cvar_t collision_leavenudge = {0, "collision_leavenudge", "0", "how much to bias collision exit fraction"};
  15 cvar_t collision_prefernudgedfraction = {0, "collision_prefernudgedfraction", "1", "whether to sort collision events by nudged fraction (1) or real fraction (0)"};
  16
  17 void Collision_Init (void)
  18 {
  19         Cvar_RegisterVariable(&collision_impactnudge);
  20         Cvar_RegisterVariable(&collision_startnudge);
  21         Cvar_RegisterVariable(&collision_endnudge);
  22         Cvar_RegisterVariable(&collision_enternudge);
  23         Cvar_RegisterVariable(&collision_leavenudge);
  24         Cvar_RegisterVariable(&collision_prefernudgedfraction);
  25 }
  26
  27
  28
  29
  30
  31
  32
  33
  34
  35
  36
  37
  38
  39
  40 void Collision_PrintBrushAsQHull(colbrushf_t *brush, const char *name)
  41 {
  42         int i;
  43         Con_Printf("3 %s\n%i\n", name, brush->numpoints);
  44         for (i = 0;i < brush->numpoints;i++)
  45                 Con_Printf("%f %f %f\n", brush->points[i].v[0], brush->points[i].v[1], brush->points[i].v[2]);
  46         // FIXME: optimize!
  47         Con_Printf("4\n%i\n", brush->numplanes);
  48         for (i = 0;i < brush->numplanes;i++)
  49                 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);
  50 }
  51
  52 void Collision_ValidateBrush(colbrushf_t *brush)
  53 {
  54         int j, k, pointsoffplanes, pointonplanes, pointswithinsufficientplanes, printbrush;
  55         float d;
  56         printbrush = false;
  57         if (!brush->numpoints)
  58         {
  59                 Con_Print("Collision_ValidateBrush: brush with no points!\n");
  60                 printbrush = true;
  61         }
  62 #if 0
  63         // it's ok for a brush to have one point and no planes...
  64         if (brush->numplanes == 0 && brush->numpoints != 1)
  65         {
  66                 Con_Print("Collision_ValidateBrush: brush with no planes and more than one point!\n");
  67                 printbrush = true;
  68         }
  69 #endif
  70         if (brush->numplanes)
  71         {
  72                 pointsoffplanes = 0;
  73                 pointswithinsufficientplanes = 0;
  74                 for (k = 0;k < brush->numplanes;k++)
  75                         if (DotProduct(brush->planes[k].normal, brush->planes[k].normal) < 0.0001f)
  76                                 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);
  77                 for (j = 0;j < brush->numpoints;j++)
  78                 {
  79                         pointonplanes = 0;
  80                         for (k = 0;k < brush->numplanes;k++)
  81                         {
  82                                 d = DotProduct(brush->points[j].v, brush->planes[k].normal) - brush->planes[k].dist;
  83                                 if (d > COLLISION_PLANE_DIST_EPSILON)
  84                                 {
  85                                         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);
  86                                         printbrush = true;
  87                                 }
  88                                 if (fabs(d) > COLLISION_PLANE_DIST_EPSILON)
  89                                         pointsoffplanes++;
  90                                 else
  91                                         pointonplanes++;
  92                         }
  93                         if (pointonplanes < 3)
  94                                 pointswithinsufficientplanes++;
  95                 }
  96                 if (pointswithinsufficientplanes)
  97                 {
  98                         Con_Print("Collision_ValidateBrush: some points have insufficient planes, every point must be on at least 3 planes to form a corner.\n");
  99                         printbrush = true;
 100                 }
 101                 if (pointsoffplanes == 0) // all points are on all planes
 102                 {
 103                         Con_Print("Collision_ValidateBrush: all points lie on all planes (degenerate, no brush volume!)\n");
 104                         printbrush = true;
 105                 }
 106         }
 107         if (printbrush)
 108                 Collision_PrintBrushAsQHull(brush, "unnamed");
 109 }
 110
 111 float nearestplanedist_float(const float *normal, const colpointf_t *points, int numpoints)
 112 {
 113         float dist, bestdist;
 114         if (!numpoints)
 115                 return 0;
 116         bestdist = DotProduct(points->v, normal);
 117         points++;
 118         while(--numpoints)
 119         {
 120                 dist = DotProduct(points->v, normal);
 121                 bestdist = min(bestdist, dist);
 122                 points++;
 123         }
 124         return bestdist;
 125 }
 126
 127 float furthestplanedist_float(const float *normal, const colpointf_t *points, int numpoints)
 128 {
 129         float dist, bestdist;
 130         if (!numpoints)
 131                 return 0;
 132         bestdist = DotProduct(points->v, normal);
 133         points++;
 134         while(--numpoints)
 135         {
 136                 dist = DotProduct(points->v, normal);
 137                 bestdist = max(bestdist, dist);
 138                 points++;
 139         }
 140         return bestdist;
 141 }
 142
 143
 144 colbrushf_t *Collision_NewBrushFromPlanes(mempool_t *mempool, int numoriginalplanes, const colplanef_t *originalplanes, int supercontents)
 145 {
 146         // TODO: planesbuf could be replaced by a remapping table
 147         int j, k, m, w, xyzflags;
 148         int numpointsbuf = 0, maxpointsbuf = 256, numplanesbuf = 0, maxplanesbuf = 256, numelementsbuf = 0, maxelementsbuf = 256;
 149         double maxdist;
 150         colbrushf_t *brush;
 151         colpointf_t pointsbuf[256];
 152         colplanef_t planesbuf[256];
 153         int elementsbuf[1024];
 154         int polypointbuf[256];
 155         int pmaxpoints = 64;
 156         int pnumpoints;
 157         double p[2][3*64];
 158 #if 0
 159         // enable these if debugging to avoid seeing garbage in unused data
 160         memset(pointsbuf, 0, sizeof(pointsbuf));
 161         memset(planesbuf, 0, sizeof(planesbuf));
 162         memset(elementsbuf, 0, sizeof(elementsbuf));
 163         memset(polypointbuf, 0, sizeof(polypointbuf));
 164         memset(p, 0, sizeof(p));
 165 #endif
 166         // figure out how large a bounding box we need to properly compute this brush
 167         maxdist = 0;
 168         for (j = 0;j < numoriginalplanes;j++)
 169                 maxdist = max(maxdist, fabs(originalplanes[j].dist));
 170         // now make it large enough to enclose the entire brush, and round it off to a reasonable multiple of 1024
 171         maxdist = floor(maxdist * (4.0 / 1024.0) + 2) * 1024.0;
 172         // construct a collision brush (points, planes, and renderable mesh) from
 173         // a set of planes, this also optimizes out any unnecessary planes (ones
 174         // whose polygon is clipped away by the other planes)
 175         for (j = 0;j < numoriginalplanes;j++)
 176         {
 177                 // add the plane uniquely (no duplicates)
 178                 for (k = 0;k < numplanesbuf;k++)
 179                         if (VectorCompare(planesbuf[k].normal, originalplanes[j].normal) && planesbuf[k].dist == originalplanes[j].dist)
 180                                 break;
 181                 // if the plane is a duplicate, skip it
 182                 if (k < numplanesbuf)
 183                         continue;
 184                 // check if there are too many and skip the brush
 185                 if (numplanesbuf >= maxplanesbuf)
 186                 {
 187                         Con_DPrint("Collision_NewBrushFromPlanes: failed to build collision brush: too many planes for buffer\n");
 188                         return NULL;
 189                 }
 190
 191                 // add the new plane
 192                 VectorCopy(originalplanes[j].normal, planesbuf[numplanesbuf].normal);
 193                 planesbuf[numplanesbuf].dist = originalplanes[j].dist;
 194                 planesbuf[numplanesbuf].q3surfaceflags = originalplanes[j].q3surfaceflags;
 195                 planesbuf[numplanesbuf].texture = originalplanes[j].texture;
 196                 numplanesbuf++;
 197
 198                 // create a large polygon from the plane
 199                 w = 0;
 200                 PolygonD_QuadForPlane(p[w], originalplanes[j].normal[0], originalplanes[j].normal[1], originalplanes[j].normal[2], originalplanes[j].dist, maxdist);
 201                 pnumpoints = 4;
 202                 // clip it by all other planes
 203                 for (k = 0;k < numoriginalplanes && pnumpoints >= 3 && pnumpoints <= pmaxpoints;k++)
 204                 {
 205                         // skip the plane this polygon
 206                         // (nothing happens if it is processed, this is just an optimization)
 207                         if (k != j)
 208                         {
 209                                 // we want to keep the inside of the brush plane so we flip
 210                                 // the cutting plane
 211                                 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);
 212                                 w = !w;
 213                         }
 214                 }
 215
 216                 // if nothing is left, skip it
 217                 if (pnumpoints < 3)
 218                 {
 219                         //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);
 220                         continue;
 221                 }
 222
 223                 for (k = 0;k < pnumpoints;k++)
 224                 {
 225                         int l, m;
 226                         m = 0;
 227                         for (l = 0;l < numoriginalplanes;l++)
 228                                 if (fabs(DotProduct(&p[w][k*3], originalplanes[l].normal) - originalplanes[l].dist) < COLLISION_PLANE_DIST_EPSILON)
 229                                         m++;
 230                         if (m < 3)
 231                                 break;
 232                 }
 233                 if (k < pnumpoints)
 234                 {
 235                         Con_DPrintf("Collision_NewBrushFromPlanes: warning: polygon point does not lie on at least 3 planes\n");
 236                         //return NULL;
 237                 }
 238
 239                 // check if there are too many polygon vertices for buffer
 240                 if (pnumpoints > pmaxpoints)
 241                 {
 242                         Con_DPrint("Collision_NewBrushFromPlanes: failed to build collision brush: too many points for buffer\n");
 243                         return NULL;
 244                 }
 245
 246                 // check if there are too many triangle elements for buffer
 247                 if (numelementsbuf + (pnumpoints - 2) * 3 > maxelementsbuf)
 248                 {
 249                         Con_DPrint("Collision_NewBrushFromPlanes: failed to build collision brush: too many triangle elements for buffer\n");
 250                         return NULL;
 251                 }
 252
 253                 for (k = 0;k < pnumpoints;k++)
 254                 {
 255                         float v[3];
 256                         // downgrade to float precision before comparing
 257                         VectorCopy(&p[w][k*3], v);
 258
 259                         // check if there is already a matching point (no duplicates)
 260                         for (m = 0;m < numpointsbuf;m++)
 261                                 if (VectorDistance2(v, pointsbuf[m].v) < COLLISION_SNAP2)
 262                                         break;
 263
 264                         // if there is no match, add a new one
 265                         if (m == numpointsbuf)
 266                         {
 267                                 // check if there are too many and skip the brush
 268                                 if (numpointsbuf >= maxpointsbuf)
 269                                 {
 270                                         Con_DPrint("Collision_NewBrushFromPlanes: failed to build collision brush: too many points for buffer\n");
 271                                         return NULL;
 272                                 }
 273                                 // add the new one
 274                                 VectorCopy(&p[w][k*3], pointsbuf[numpointsbuf].v);
 275                                 numpointsbuf++;
 276                         }
 277
 278                         // store the index into a buffer
 279                         polypointbuf[k] = m;
 280                 }
 281
 282                 // add the triangles for the polygon
 283                 // (this particular code makes a triangle fan)
 284                 for (k = 0;k < pnumpoints - 2;k++)
 285                 {
 286                         elementsbuf[numelementsbuf++] = polypointbuf[0];
 287                         elementsbuf[numelementsbuf++] = polypointbuf[k + 1];
 288                         elementsbuf[numelementsbuf++] = polypointbuf[k + 2];
 289                 }
 290         }
 291
 292         // if nothing is left, there's nothing to allocate
 293         if (numplanesbuf < 4)
 294         {
 295                 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);
 296                 return NULL;
 297         }
 298
 299         // if no triangles or points could be constructed, then this routine failed but the brush is not discarded
 300         if (numelementsbuf < 12 || numpointsbuf < 4)
 301                 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);
 302
 303         // validate plane distances
 304         for (j = 0;j < numplanesbuf;j++)
 305         {
 306                 float d = furthestplanedist_float(planesbuf[j].normal, pointsbuf, numpointsbuf);
 307                 if (fabs(planesbuf[j].dist - d) > COLLISION_PLANE_DIST_EPSILON)
 308                         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);
 309         }
 310
 311         // allocate the brush and copy to it
 312         brush = (colbrushf_t *)Mem_Alloc(mempool, sizeof(colbrushf_t) + sizeof(colpointf_t) * numpointsbuf + sizeof(colplanef_t) * numplanesbuf + sizeof(int) * numelementsbuf);
 313         brush->supercontents = supercontents;
 314         brush->numplanes = numplanesbuf;
 315         brush->numpoints = numpointsbuf;
 316         brush->numtriangles = numelementsbuf / 3;
 317         brush->planes = (colplanef_t *)(brush + 1);
 318         brush->points = (colpointf_t *)(brush->planes + brush->numplanes);
 319         brush->elements = (int *)(brush->points + brush->numpoints);
 320         for (j = 0;j < brush->numpoints;j++)
 321         {
 322                 brush->points[j].v[0] = pointsbuf[j].v[0];
 323                 brush->points[j].v[1] = pointsbuf[j].v[1];
 324                 brush->points[j].v[2] = pointsbuf[j].v[2];
 325         }
 326         for (j = 0;j < brush->numplanes;j++)
 327         {
 328                 brush->planes[j].normal[0] = planesbuf[j].normal[0];
 329                 brush->planes[j].normal[1] = planesbuf[j].normal[1];
 330                 brush->planes[j].normal[2] = planesbuf[j].normal[2];
 331                 brush->planes[j].dist = planesbuf[j].dist;
 332                 brush->planes[j].q3surfaceflags = planesbuf[j].q3surfaceflags;
 333                 brush->planes[j].texture = planesbuf[j].texture;
 334         }
 335         for (j = 0;j < brush->numtriangles * 3;j++)
 336                 brush->elements[j] = elementsbuf[j];
 337
 338         xyzflags = 0;
 339         VectorClear(brush->mins);
 340         VectorClear(brush->maxs);
 341         for (j = 0;j < min(6, numoriginalplanes);j++)
 342         {
 343                      if (originalplanes[j].normal[0] ==  1) {xyzflags |=  1;brush->maxs[0] =  originalplanes[j].dist;}
 344                 else if (originalplanes[j].normal[0] == -1) {xyzflags |=  2;brush->mins[0] = -originalplanes[j].dist;}
 345                 else if (originalplanes[j].normal[1] ==  1) {xyzflags |=  4;brush->maxs[1] =  originalplanes[j].dist;}
 346                 else if (originalplanes[j].normal[1] == -1) {xyzflags |=  8;brush->mins[1] = -originalplanes[j].dist;}
 347                 else if (originalplanes[j].normal[2] ==  1) {xyzflags |= 16;brush->maxs[2] =  originalplanes[j].dist;}
 348                 else if (originalplanes[j].normal[2] == -1) {xyzflags |= 32;brush->mins[2] = -originalplanes[j].dist;}
 349         }
 350         // if not all xyzflags were set, then this is not a brush from q3map/q3map2, and needs reconstruction of the bounding box
 351         // (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)
 352         if (xyzflags != 63)
 353         {
 354                 VectorCopy(brush->points[0].v, brush->mins);
 355                 VectorCopy(brush->points[0].v, brush->maxs);
 356                 for (j = 1;j < brush->numpoints;j++)
 357                 {
 358                         brush->mins[0] = min(brush->mins[0], brush->points[j].v[0]);
 359                         brush->mins[1] = min(brush->mins[1], brush->points[j].v[1]);
 360                         brush->mins[2] = min(brush->mins[2], brush->points[j].v[2]);
 361                         brush->maxs[0] = max(brush->maxs[0], brush->points[j].v[0]);
 362                         brush->maxs[1] = max(brush->maxs[1], brush->points[j].v[1]);
 363                         brush->maxs[2] = max(brush->maxs[2], brush->points[j].v[2]);
 364                 }
 365         }
 366         brush->mins[0] -= 1;
 367         brush->mins[1] -= 1;
 368         brush->mins[2] -= 1;
 369         brush->maxs[0] += 1;
 370         brush->maxs[1] += 1;
 371         brush->maxs[2] += 1;
 372         Collision_ValidateBrush(brush);
 373         return brush;
 374 }
 375
 376
 377
 378 void Collision_CalcPlanesForPolygonBrushFloat(colbrushf_t *brush)
 379 {
 380         int i;
 381         float edge0[3], edge1[3], edge2[3], normal[3], dist, bestdist;
 382         colpointf_t *p, *p2;
 383
 384         // FIXME: these probably don't actually need to be normalized if the collision code does not care
 385         if (brush->numpoints == 3)
 386         {
 387                 // optimized triangle case
 388                 TriangleNormal(brush->points[0].v, brush->points[1].v, brush->points[2].v, brush->planes[0].normal);
 389                 if (DotProduct(brush->planes[0].normal, brush->planes[0].normal) < 0.0001f)
 390                 {
 391                         // there's no point in processing a degenerate triangle (GIGO - Garbage In, Garbage Out)
 392                         brush->numplanes = 0;
 393                         return;
 394                 }
 395                 else
 396                 {
 397                         brush->numplanes = 5;
 398                         VectorNormalize(brush->planes[0].normal);
 399                         brush->planes[0].dist = DotProduct(brush->points->v, brush->planes[0].normal);
 400                         VectorNegate(brush->planes[0].normal, brush->planes[1].normal);
 401                         brush->planes[1].dist = -brush->planes[0].dist;
 402                         VectorSubtract(brush->points[2].v, brush->points[0].v, edge0);
 403                         VectorSubtract(brush->points[0].v, brush->points[1].v, edge1);
 404                         VectorSubtract(brush->points[1].v, brush->points[2].v, edge2);
 405 #if 1
 406                         {
 407                                 float projectionnormal[3], projectionedge0[3], projectionedge1[3], projectionedge2[3];
 408                                 int i, best;
 409                                 float dist, bestdist;
 410                                 bestdist = fabs(brush->planes[0].normal[0]);
 411                                 best = 0;
 412                                 for (i = 1;i < 3;i++)
 413                                 {
 414                                         dist = fabs(brush->planes[0].normal[i]);
 415                                         if (bestdist < dist)
 416                                         {
 417                                                 bestdist = dist;
 418                                                 best = i;
 419                                         }
 420                                 }
 421                                 VectorClear(projectionnormal);
 422                                 if (brush->planes[0].normal[best] < 0)
 423                                         projectionnormal[best] = -1;
 424                                 else
 425                                         projectionnormal[best] = 1;
 426                                 VectorCopy(edge0, projectionedge0);
 427                                 VectorCopy(edge1, projectionedge1);
 428                                 VectorCopy(edge2, projectionedge2);
 429                                 projectionedge0[best] = 0;
 430                                 projectionedge1[best] = 0;
 431                                 projectionedge2[best] = 0;
 432                                 CrossProduct(projectionedge0, projectionnormal, brush->planes[2].normal);
 433                                 CrossProduct(projectionedge1, projectionnormal, brush->planes[3].normal);
 434                                 CrossProduct(projectionedge2, projectionnormal, brush->planes[4].normal);
 435                         }
 436 #else
 437                         CrossProduct(edge0, brush->planes->normal, brush->planes[2].normal);
 438                         CrossProduct(edge1, brush->planes->normal, brush->planes[3].normal);
 439                         CrossProduct(edge2, brush->planes->normal, brush->planes[4].normal);
 440 #endif
 441                         VectorNormalize(brush->planes[2].normal);
 442                         VectorNormalize(brush->planes[3].normal);
 443                         VectorNormalize(brush->planes[4].normal);
 444                         brush->planes[2].dist = DotProduct(brush->points[2].v, brush->planes[2].normal);
 445                         brush->planes[3].dist = DotProduct(brush->points[0].v, brush->planes[3].normal);
 446                         brush->planes[4].dist = DotProduct(brush->points[1].v, brush->planes[4].normal);
 447
 448                         if (developer.integer >= 100)
 449                         {
 450                                 // validation code
 451 #if 0
 452                                 float temp[3];
 453
 454                                 VectorSubtract(brush->points[0].v, brush->points[1].v, edge0);
 455                                 VectorSubtract(brush->points[2].v, brush->points[1].v, edge1);
 456                                 CrossProduct(edge0, edge1, normal);
 457                                 VectorNormalize(normal);
 458                                 VectorSubtract(normal, brush->planes[0].normal, temp);
 459                                 if (VectorLength(temp) > 0.01f)
 460                                         Con_Printf("Collision_CalcPlanesForPolygonBrushFloat: TriangleNormal gave wrong answer (%f %f %f != correct answer %f %f %f)\n", brush->planes->normal[0], brush->planes->normal[1], brush->planes->normal[2], normal[0], normal[1], normal[2]);
 461                                 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)
 462                                         Con_Printf("Collision_CalcPlanesForPolygonBrushFloat: plane 1 (%f %f %f %f) is not opposite plane 0 (%f %f %f %f)\n", brush->planes[1].normal[0], brush->planes[1].normal[1], brush->planes[1].normal[2], brush->planes[1].dist, brush->planes[0].normal[0], brush->planes[0].normal[1], brush->planes[0].normal[2], brush->planes[0].dist);
 463 #if 0
 464                                 if (fabs(DotProduct(brush->planes[2].normal, brush->planes[0].normal)) > 0.01f)
 465                                         Con_Printf("Collision_CalcPlanesForPolygonBrushFloat: plane 2 (%f %f %f %f) is not perpendicular to plane 0 (%f %f %f %f)\n", brush->planes[2].normal[0], brush->planes[2].normal[1], brush->planes[2].normal[2], brush->planes[2].dist, brush->planes[0].normal[0], brush->planes[0].normal[1], brush->planes[0].normal[2], brush->planes[2].dist);
 466                                 if (fabs(DotProduct(brush->planes[3].normal, brush->planes[0].normal)) > 0.01f)
 467                                         Con_Printf("Collision_CalcPlanesForPolygonBrushFloat: plane 3 (%f %f %f %f) is not perpendicular to plane 0 (%f %f %f %f)\n", brush->planes[3].normal[0], brush->planes[3].normal[1], brush->planes[3].normal[2], brush->planes[3].dist, brush->planes[0].normal[0], brush->planes[0].normal[1], brush->planes[0].normal[2], brush->planes[3].dist);
 468                                 if (fabs(DotProduct(brush->planes[4].normal, brush->planes[0].normal)) > 0.01f)
 469                                         Con_Printf("Collision_CalcPlanesForPolygonBrushFloat: plane 4 (%f %f %f %f) is not perpendicular to plane 0 (%f %f %f %f)\n", brush->planes[4].normal[0], brush->planes[4].normal[1], brush->planes[4].normal[2], brush->planes[4].dist, brush->planes[0].normal[0], brush->planes[0].normal[1], brush->planes[0].normal[2], brush->planes[4].dist);
 470                                 if (fabs(DotProduct(brush->planes[2].normal, edge0)) > 0.01f)
 471                                         Con_Printf("Collision_CalcPlanesForPolygonBrushFloat: plane 2 (%f %f %f %f) is not perpendicular to edge 0 (%f %f %f to %f %f %f)\n", brush->planes[2].normal[0], brush->planes[2].normal[1], brush->planes[2].normal[2], brush->planes[2].dist, brush->points[2].v[0], brush->points[2].v[1], brush->points[2].v[2], brush->points[0].v[0], brush->points[0].v[1], brush->points[0].v[2]);
 472                                 if (fabs(DotProduct(brush->planes[3].normal, edge1)) > 0.01f)
 473                                         Con_Printf("Collision_CalcPlanesForPolygonBrushFloat: plane 3 (%f %f %f %f) is not perpendicular to edge 1 (%f %f %f to %f %f %f)\n", brush->planes[3].normal[0], brush->planes[3].normal[1], brush->planes[3].normal[2], brush->planes[3].dist, brush->points[0].v[0], brush->points[0].v[1], brush->points[0].v[2], brush->points[1].v[0], brush->points[1].v[1], brush->points[1].v[2]);
 474                                 if (fabs(DotProduct(brush->planes[4].normal, edge2)) > 0.01f)
 475                                         Con_Printf("Collision_CalcPlanesForPolygonBrushFloat: plane 4 (%f %f %f %f) is not perpendicular to edge 2 (%f %f %f to %f %f %f)\n", brush->planes[4].normal[0], brush->planes[4].normal[1], brush->planes[4].normal[2], brush->planes[4].dist, brush->points[1].v[0], brush->points[1].v[1], brush->points[1].v[2], brush->points[2].v[0], brush->points[2].v[1], brush->points[2].v[2]);
 476 #endif
 477 #endif
 478                                 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)
 479                                         Con_Printf("Collision_CalcPlanesForPolygonBrushFloat: edges (%f %f %f to %f %f %f to %f %f %f) off front plane 0 (%f %f %f %f)\n", brush->points[0].v[0], brush->points[0].v[1], brush->points[0].v[2], brush->points[1].v[0], brush->points[1].v[1], brush->points[1].v[2], brush->points[2].v[0], brush->points[2].v[1], brush->points[2].v[2], brush->planes[0].normal[0], brush->planes[0].normal[1], brush->planes[0].normal[2], brush->planes[0].dist);
 480                                 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)
 481                                         Con_Printf("Collision_CalcPlanesForPolygonBrushFloat: edges (%f %f %f to %f %f %f to %f %f %f) off back plane 1 (%f %f %f %f)\n", brush->points[0].v[0], brush->points[0].v[1], brush->points[0].v[2], brush->points[1].v[0], brush->points[1].v[1], brush->points[1].v[2], brush->points[2].v[0], brush->points[2].v[1], brush->points[2].v[2], brush->planes[1].normal[0], brush->planes[1].normal[1], brush->planes[1].normal[2], brush->planes[1].dist);
 482                                 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)
 483                                         Con_Printf("Collision_CalcPlanesForPolygonBrushFloat: edge 0 (%f %f %f to %f %f %f) off front plane 2 (%f %f %f %f)\n", brush->points[2].v[0], brush->points[2].v[1], brush->points[2].v[2], brush->points[0].v[0], brush->points[0].v[1], brush->points[0].v[2], brush->planes[2].normal[0], brush->planes[2].normal[1], brush->planes[2].normal[2], brush->planes[2].dist);
 484                                 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)
 485                                         Con_Printf("Collision_CalcPlanesForPolygonBrushFloat: edge 0 (%f %f %f to %f %f %f) off front plane 2 (%f %f %f %f)\n", brush->points[0].v[0], brush->points[0].v[1], brush->points[0].v[2], brush->points[1].v[0], brush->points[1].v[1], brush->points[1].v[2], brush->planes[3].normal[0], brush->planes[3].normal[1], brush->planes[3].normal[2], brush->planes[3].dist);
 486                                 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)
 487                                         Con_Printf("Collision_CalcPlanesForPolygonBrushFloat: edge 0 (%f %f %f to %f %f %f) off front plane 2 (%f %f %f %f)\n", brush->points[1].v[0], brush->points[1].v[1], brush->points[1].v[2], brush->points[2].v[0], brush->points[2].v[1], brush->points[2].v[2], brush->planes[4].normal[0], brush->planes[4].normal[1], brush->planes[4].normal[2], brush->planes[4].dist);
 488                         }
 489                 }
 490         }
 491         else
 492         {
 493                 // choose best surface normal for polygon's plane
 494                 bestdist = 0;
 495                 for (i = 0, p = brush->points + 1;i < brush->numpoints - 2;i++, p++)
 496                 {
 497                         VectorSubtract(p[-1].v, p[0].v, edge0);
 498                         VectorSubtract(p[1].v, p[0].v, edge1);
 499                         CrossProduct(edge0, edge1, normal);
 500                         //TriangleNormal(p[-1].v, p[0].v, p[1].v, normal);
 501                         dist = DotProduct(normal, normal);
 502                         if (i == 0 || bestdist < dist)
 503                         {
 504                                 bestdist = dist;
 505                                 VectorCopy(normal, brush->planes->normal);
 506                         }
 507                 }
 508                 if (bestdist < 0.0001f)
 509                 {
 510                         // there's no point in processing a degenerate triangle (GIGO - Garbage In, Garbage Out)
 511                         brush->numplanes = 0;
 512                         return;
 513                 }
 514                 else
 515                 {
 516                         brush->numplanes = brush->numpoints + 2;
 517                         VectorNormalize(brush->planes->normal);
 518                         brush->planes->dist = DotProduct(brush->points->v, brush->planes->normal);
 519
 520                         // negate plane to create other side
 521                         VectorNegate(brush->planes[0].normal, brush->planes[1].normal);
 522                         brush->planes[1].dist = -brush->planes[0].dist;
 523                         for (i = 0, p = brush->points + (brush->numpoints - 1), p2 = brush->points;i < brush->numpoints;i++, p = p2, p2++)
 524                         {
 525                                 VectorSubtract(p->v, p2->v, edge0);
 526                                 CrossProduct(edge0, brush->planes->normal, brush->planes[i + 2].normal);
 527                                 VectorNormalize(brush->planes[i + 2].normal);
 528                                 brush->planes[i + 2].dist = DotProduct(p->v, brush->planes[i + 2].normal);
 529                         }
 530                 }
 531         }
 532
 533         if (developer.integer >= 100)
 534         {
 535                 // validity check - will be disabled later
 536                 Collision_ValidateBrush(brush);
 537                 for (i = 0;i < brush->numplanes;i++)
 538                 {
 539                         int j;
 540                         for (j = 0, p = brush->points;j < brush->numpoints;j++, p++)
 541                                 if (DotProduct(p->v, brush->planes[i].normal) > brush->planes[i].dist + COLLISION_PLANE_DIST_EPSILON)
 542                                         Con_Printf("Error in brush plane generation, plane %i\n", i);
 543                 }
 544         }
 545 }
 546
 547 colbrushf_t *Collision_AllocBrushFromPermanentPolygonFloat(mempool_t *mempool, int numpoints, float *points, int supercontents)
 548 {
 549         colbrushf_t *brush;
 550         brush = (colbrushf_t *)Mem_Alloc(mempool, sizeof(colbrushf_t) + sizeof(colplanef_t) * (numpoints + 2));
 551         brush->supercontents = supercontents;
 552         brush->numpoints = numpoints;
 553         brush->numplanes = numpoints + 2;
 554         brush->planes = (colplanef_t *)(brush + 1);
 555         brush->points = (colpointf_t *)points;
 556         Sys_Error("Collision_AllocBrushFromPermanentPolygonFloat: FIXME: this code needs to be updated to generate a mesh...");
 557         return brush;
 558 }
 559
 560 // NOTE: start and end of each brush pair must have same numplanes/numpoints
 561 void Collision_TraceBrushBrushFloat(trace_t *trace, const colbrushf_t *thisbrush_start, const colbrushf_t *thisbrush_end, const colbrushf_t *thatbrush_start, const colbrushf_t *thatbrush_end)
 562 {
 563         int nplane, nplane2, hitq3surfaceflags = 0;
 564         float enterfrac = -1, leavefrac = 1, d1, d2, f, imove, newimpactnormal[3], enterfrac2 = -1;
 565         const colplanef_t *startplane, *endplane;
 566         texture_t *hittexture = NULL;
 567
 568         VectorClear(newimpactnormal);
 569
 570         for (nplane = 0;nplane < thatbrush_start->numplanes + thisbrush_start->numplanes;nplane++)
 571         {
 572                 nplane2 = nplane;
 573                 if (nplane2 >= thatbrush_start->numplanes)
 574                 {
 575                         nplane2 -= thatbrush_start->numplanes;
 576                         startplane = thisbrush_start->planes + nplane2;
 577                         endplane = thisbrush_end->planes + nplane2;
 578                         if (developer.integer >= 100)
 579                         {
 580                                 // any brush with degenerate planes is not worth handling
 581                                 if (DotProduct(startplane->normal, startplane->normal) < 0.9f || DotProduct(endplane->normal, endplane->normal) < 0.9f)
 582                                 {
 583                                         Con_Print("Collision_TraceBrushBrushFloat: degenerate thisbrush plane!\n");
 584                                         return;
 585                                 }
 586                                 f = furthestplanedist_float(startplane->normal, thisbrush_start->points, thisbrush_start->numpoints);
 587                                 if (fabs(f - startplane->dist) > COLLISION_PLANE_DIST_EPSILON)
 588                                         Con_Printf("startplane->dist %f != calculated %f (thisbrush_start)\n", startplane->dist, f);
 589                         }
 590                         d1 = nearestplanedist_float(startplane->normal, thisbrush_start->points, thisbrush_start->numpoints) - furthestplanedist_float(startplane->normal, thatbrush_start->points, thatbrush_start->numpoints) - collision_startnudge.value;
 591                         d2 = nearestplanedist_float(endplane->normal, thisbrush_end->points, thisbrush_end->numpoints) - furthestplanedist_float(endplane->normal, thatbrush_end->points, thatbrush_end->numpoints) - collision_endnudge.value;
 592                 }
 593                 else
 594                 {
 595                         startplane = thatbrush_start->planes + nplane2;
 596                         endplane = thatbrush_end->planes + nplane2;
 597                         if (developer.integer >= 100)
 598                         {
 599                                 // any brush with degenerate planes is not worth handling
 600                                 if (DotProduct(startplane->normal, startplane->normal) < 0.9f || DotProduct(endplane->normal, endplane->normal) < 0.9f)
 601                                 {
 602                                         Con_Print("Collision_TraceBrushBrushFloat: degenerate thatbrush plane!\n");
 603                                         return;
 604                                 }
 605                                 f = furthestplanedist_float(startplane->normal, thatbrush_start->points, thatbrush_start->numpoints);
 606                                 if (fabs(f - startplane->dist) > COLLISION_PLANE_DIST_EPSILON)
 607                                         Con_Printf("startplane->dist %f != calculated %f (thatbrush_start)\n", startplane->dist, f);
 608                         }
 609                         d1 = nearestplanedist_float(startplane->normal, thisbrush_start->points, thisbrush_start->numpoints) - startplane->dist - collision_startnudge.value;
 610                         d2 = nearestplanedist_float(endplane->normal, thisbrush_end->points, thisbrush_end->numpoints) - endplane->dist - collision_endnudge.value;
 611                 }
 612                 //Con_Printf("%c%i: d1 = %f, d2 = %f, d1 / (d1 - d2) = %f\n", nplane2 != nplane ? 'b' : 'a', nplane2, d1, d2, d1 / (d1 - d2));
 613
 614                 if (d1 > d2)
 615                 {
 616                         // moving into brush
 617                         if (d2 > 0)
 618                                 return;
 619                         if (d1 > 0)
 620                         {
 621                                 // enter
 622                                 imove = 1 / (d1 - d2);
 623                                 f = (d1 - collision_enternudge.value) * imove;
 624                                 // check if this will reduce the collision time range
 625                                 if (enterfrac < f)
 626                                 {
 627                                         // reduced collision time range
 628                                         enterfrac = f;
 629                                         // if the collision time range is now empty, no collision
 630                                         if (enterfrac > leavefrac)
 631                                                 return;
 632                                         // if the collision would be further away than the trace's
 633                                         // existing collision data, we don't care about this
 634                                         // collision
 635                                         if (enterfrac > trace->realfraction)
 636                                                 return;
 637                                         // calculate the nudged fraction and impact normal we'll
 638                                         // need if we accept this collision later
 639                                         enterfrac2 = f - collision_impactnudge.value * imove;
 640                                         VectorLerp(startplane->normal, enterfrac, endplane->normal, newimpactnormal);
 641                                         hitq3surfaceflags = startplane->q3surfaceflags;
 642                                         hittexture = startplane->texture;
 643                                 }
 644                         }
 645                 }
 646                 else
 647                 {
 648                         // moving out of brush
 649                         if (d1 > 0)
 650                                 return;
 651                         if (d2 > 0)
 652                         {
 653                                 // leave
 654                                 f = (d1 + collision_leavenudge.value) / (d1 - d2);
 655                                 // check if this will reduce the collision time range
 656                                 if (leavefrac > f)
 657                                 {
 658                                         // reduced collision time range
 659                                         leavefrac = f;
 660                                         // if the collision time range is now empty, no collision
 661                                         if (enterfrac > leavefrac)
 662                                                 return;
 663                                 }
 664                         }
 665                 }
 666         }
 667
 668         // at this point we know the trace overlaps the brush because it was not
 669         // rejected at any point in the loop above
 670
 671         // see if this brush can block the trace or not according to contents
 672         if (trace->hitsupercontentsmask & thatbrush_start->supercontents)
 673         {
 674                 if (enterfrac == -1)
 675                 {
 676                         trace->startsupercontents |= thatbrush_start->supercontents;
 677                         trace->startsolid = true;
 678                         if (leavefrac < 1)
 679                                 trace->allsolid = true;
 680                 }
 681                 // store out the impact information
 682                 trace->hitsupercontents = thatbrush_start->supercontents;
 683                 trace->hitq3surfaceflags = hitq3surfaceflags;
 684                 trace->hittexture = hittexture;
 685                 trace->realfraction = bound(0, enterfrac, 1);
 686                 trace->fraction = bound(0, enterfrac2, 1);
 687                 if (collision_prefernudgedfraction.integer)
 688                         trace->realfraction = trace->fraction;
 689                 VectorCopy(newimpactnormal, trace->plane.normal);
 690         }
 691         else
 692         {
 693                 // this brush can not block the trace, but it can update start contents
 694                 if (enterfrac == -1)
 695                         trace->startsupercontents |= thatbrush_start->supercontents;
 696         }
 697 }
 698
 699 // NOTE: start and end brush pair must have same numplanes/numpoints
 700 void Collision_TraceLineBrushFloat(trace_t *trace, const vec3_t linestart, const vec3_t lineend, const colbrushf_t *thatbrush_start, const colbrushf_t *thatbrush_end)
 701 {
 702         int nplane, hitq3surfaceflags = 0;
 703         float enterfrac = -1, leavefrac = 1, d1, d2, f, imove, newimpactnormal[3], enterfrac2 = -1;
 704         const colplanef_t *startplane, *endplane;
 705         texture_t *hittexture = NULL;
 706
 707         VectorClear(newimpactnormal);
 708
 709         for (nplane = 0;nplane < thatbrush_start->numplanes;nplane++)
 710         {
 711                 startplane = thatbrush_start->planes + nplane;
 712                 endplane = thatbrush_end->planes + nplane;
 713                 d1 = DotProduct(startplane->normal, linestart) - startplane->dist - collision_startnudge.value;
 714                 d2 = DotProduct(endplane->normal, lineend) - endplane->dist - collision_endnudge.value;
 715                 if (developer.integer >= 100)
 716                 {
 717                         // any brush with degenerate planes is not worth handling
 718                         if (DotProduct(startplane->normal, startplane->normal) < 0.9f || DotProduct(endplane->normal, endplane->normal) < 0.9f)
 719                         {
 720                                 Con_Print("Collision_TraceLineBrushFloat: degenerate plane!\n");
 721                                 return;
 722                         }
 723                         if (thatbrush_start->numpoints)
 724                         {
 725                                 f = furthestplanedist_float(startplane->normal, thatbrush_start->points, thatbrush_start->numpoints);
 726                                 if (fabs(f - startplane->dist) > COLLISION_PLANE_DIST_EPSILON)
 727                                         Con_Printf("startplane->dist %f != calculated %f\n", startplane->dist, f);
 728                         }
 729                 }
 730
 731                 if (d1 > d2)
 732                 {
 733                         // moving into brush
 734                         if (d2 > 0)
 735                                 return;
 736                         if (d1 > 0)
 737                         {
 738                                 // enter
 739                                 imove = 1 / (d1 - d2);
 740                                 f = (d1 - collision_enternudge.value) * imove;
 741                                 // check if this will reduce the collision time range
 742                                 if (enterfrac < f)
 743                                 {
 744                                         // reduced collision time range
 745                                         enterfrac = f;
 746                                         // if the collision time range is now empty, no collision
 747                                         if (enterfrac > leavefrac)
 748                                                 return;
 749                                         // if the collision would be further away than the trace's
 750                                         // existing collision data, we don't care about this
 751                                         // collision
 752                                         if (enterfrac > trace->realfraction)
 753                                                 return;
 754                                         // calculate the nudged fraction and impact normal we'll
 755                                         // need if we accept this collision later
 756                                         enterfrac2 = f - collision_impactnudge.value * imove;
 757                                         VectorLerp(startplane->normal, enterfrac, endplane->normal, newimpactnormal);
 758                                         hitq3surfaceflags = startplane->q3surfaceflags;
 759                                         hittexture = startplane->texture;
 760                                 }
 761                         }
 762                 }
 763                 else
 764                 {
 765                         // moving out of brush
 766                         if (d1 > 0)
 767                                 return;
 768                         if (d2 > 0)
 769                         {
 770                                 // leave
 771                                 f = (d1 + collision_leavenudge.value) / (d1 - d2);
 772                                 // check if this will reduce the collision time range
 773                                 if (leavefrac > f)
 774                                 {
 775                                         // reduced collision time range
 776                                         leavefrac = f;
 777                                         // if the collision time range is now empty, no collision
 778                                         if (enterfrac > leavefrac)
 779                                                 return;
 780                                 }
 781                         }
 782                 }
 783         }
 784
 785         // at this point we know the trace overlaps the brush because it was not
 786         // rejected at any point in the loop above
 787
 788         // see if this brush can block the trace or not according to contents
 789         if (trace->hitsupercontentsmask & thatbrush_start->supercontents)
 790         {
 791                 if (enterfrac == -1)
 792                 {
 793                         trace->startsupercontents |= thatbrush_start->supercontents;
 794                         trace->startsolid = true;
 795                         if (leavefrac < 1)
 796                                 trace->allsolid = true;
 797                 }
 798                 // store out the impact information
 799                 trace->hitsupercontents = thatbrush_start->supercontents;
 800                 trace->hitq3surfaceflags = hitq3surfaceflags;
 801                 trace->hittexture = hittexture;
 802                 trace->realfraction = bound(0, enterfrac, 1);
 803                 trace->fraction = bound(0, enterfrac2, 1);
 804                 if (collision_prefernudgedfraction.integer)
 805                         trace->realfraction = trace->fraction;
 806                 VectorCopy(newimpactnormal, trace->plane.normal);
 807         }
 808         else
 809         {
 810                 // this brush can not block the trace, but it can update start contents
 811                 if (enterfrac == -1)
 812                         trace->startsupercontents |= thatbrush_start->supercontents;
 813         }
 814 }
 815
 816 void Collision_TracePointBrushFloat(trace_t *trace, const vec3_t point, const colbrushf_t *thatbrush)
 817 {
 818         int nplane;
 819         const colplanef_t *plane;
 820
 821         for (nplane = 0, plane = thatbrush->planes;nplane < thatbrush->numplanes;nplane++, plane++)
 822                 if (DotProduct(plane->normal, point) > plane->dist)
 823                         return;
 824
 825         trace->startsupercontents |= thatbrush->supercontents;
 826         if (trace->hitsupercontentsmask & thatbrush->supercontents)
 827         {
 828                 trace->startsolid = true;
 829                 trace->allsolid = true;
 830         }
 831 }
 832
 833 static colpointf_t polyf_points[256];
 834 static colplanef_t polyf_planes[256 + 2];
 835 static colbrushf_t polyf_brush;
 836
 837 void Collision_SnapCopyPoints(int numpoints, const colpointf_t *in, colpointf_t *out, float fractionprecision, float invfractionprecision)
 838 {
 839         while (numpoints--)
 840         {
 841                 out->v[0] = floor(in->v[0] * fractionprecision + 0.5f) * invfractionprecision;
 842                 out->v[1] = floor(in->v[1] * fractionprecision + 0.5f) * invfractionprecision;
 843                 out->v[2] = floor(in->v[2] * fractionprecision + 0.5f) * invfractionprecision;
 844         }
 845 }
 846
 847 void Collision_TraceBrushPolygonFloat(trace_t *trace, const colbrushf_t *thisbrush_start, const colbrushf_t *thisbrush_end, int numpoints, const float *points, int supercontents)
 848 {
 849         if (numpoints > 256)
 850         {
 851                 Con_Print("Polygon with more than 256 points not supported yet (fixme!)\n");
 852                 return;
 853         }
 854         polyf_brush.numpoints = numpoints;
 855         polyf_brush.numplanes = numpoints + 2;
 856         //polyf_brush.points = (colpointf_t *)points;
 857         polyf_brush.planes = polyf_planes;
 858         polyf_brush.supercontents = supercontents;
 859         polyf_brush.points = polyf_points;
 860         Collision_SnapCopyPoints(numpoints, (colpointf_t *)points, polyf_points, COLLISION_SNAPSCALE, COLLISION_SNAP);
 861         Collision_CalcPlanesForPolygonBrushFloat(&polyf_brush);
 862         //Collision_PrintBrushAsQHull(&polyf_brush, "polyf_brush");
 863         Collision_TraceBrushBrushFloat(trace, thisbrush_start, thisbrush_end, &polyf_brush, &polyf_brush);
 864 }
 865
 866 void Collision_TraceBrushTriangleMeshFloat(trace_t *trace, const colbrushf_t *thisbrush_start, const colbrushf_t *thisbrush_end, int numtriangles, const int *element3i, const float *vertex3f, int supercontents, int q3surfaceflags, texture_t *texture, const vec3_t segmentmins, const vec3_t segmentmaxs)
 867 {
 868         int i;
 869         float facemins[3], facemaxs[3];
 870         polyf_brush.numpoints = 3;
 871         polyf_brush.numplanes = 5;
 872         polyf_brush.points = polyf_points;
 873         polyf_brush.planes = polyf_planes;
 874         polyf_brush.supercontents = supercontents;
 875         for (i = 0;i < polyf_brush.numplanes;i++)
 876         {
 877                 polyf_brush.planes[i].q3surfaceflags = q3surfaceflags;
 878                 polyf_brush.planes[i].texture = texture;
 879         }
 880         for (i = 0;i < numtriangles;i++, element3i += 3)
 881         {
 882                 VectorCopy(vertex3f + element3i[0] * 3, polyf_points[0].v);
 883                 VectorCopy(vertex3f + element3i[1] * 3, polyf_points[1].v);
 884                 VectorCopy(vertex3f + element3i[2] * 3, polyf_points[2].v);
 885                 Collision_SnapCopyPoints(3, polyf_points, polyf_points, COLLISION_SNAPSCALE, COLLISION_SNAP);
 886                 facemins[0] = min(polyf_points[0].v[0], min(polyf_points[1].v[0], polyf_points[2].v[0]));
 887                 facemins[1] = min(polyf_points[0].v[1], min(polyf_points[1].v[1], polyf_points[2].v[1]));
 888                 facemins[2] = min(polyf_points[0].v[2], min(polyf_points[1].v[2], polyf_points[2].v[2]));
 889                 facemaxs[0] = max(polyf_points[0].v[0], max(polyf_points[1].v[0], polyf_points[2].v[0]));
 890                 facemaxs[1] = max(polyf_points[0].v[1], max(polyf_points[1].v[1], polyf_points[2].v[1]));
 891                 facemaxs[2] = max(polyf_points[0].v[2], max(polyf_points[1].v[2], polyf_points[2].v[2]));
 892                 if (BoxesOverlap(segmentmins, segmentmaxs, facemins, facemaxs))
 893                 {
 894                         Collision_CalcPlanesForPolygonBrushFloat(&polyf_brush);
 895                         //Collision_PrintBrushAsQHull(&polyf_brush, "polyf_brush");
 896                         Collision_TraceBrushBrushFloat(trace, thisbrush_start, thisbrush_end, &polyf_brush, &polyf_brush);
 897                 }
 898         }
 899 }
 900
 901 void Collision_TraceLinePolygonFloat(trace_t *trace, const vec3_t linestart, const vec3_t lineend, int numpoints, const float *points, int supercontents)
 902 {
 903         if (numpoints > 256)
 904         {
 905                 Con_Print("Polygon with more than 256 points not supported yet (fixme!)\n");
 906                 return;
 907         }
 908         polyf_brush.numpoints = numpoints;
 909         polyf_brush.numplanes = numpoints + 2;
 910         //polyf_brush.points = (colpointf_t *)points;
 911         polyf_brush.points = polyf_points;
 912         Collision_SnapCopyPoints(numpoints, (colpointf_t *)points, polyf_points, COLLISION_SNAPSCALE, COLLISION_SNAP);
 913         polyf_brush.planes = polyf_planes;
 914         polyf_brush.supercontents = supercontents;
 915         Collision_CalcPlanesForPolygonBrushFloat(&polyf_brush);
 916         //Collision_PrintBrushAsQHull(&polyf_brush, "polyf_brush");
 917         Collision_TraceLineBrushFloat(trace, linestart, lineend, &polyf_brush, &polyf_brush);
 918 }
 919
 920 void Collision_TraceLineTriangleMeshFloat(trace_t *trace, const vec3_t linestart, const vec3_t lineend, int numtriangles, const int *element3i, const float *vertex3f, int supercontents, int q3surfaceflags, texture_t *texture, const vec3_t segmentmins, const vec3_t segmentmaxs)
 921 {
 922         int i;
 923 #if 1
 924         // FIXME: snap vertices?
 925         for (i = 0;i < numtriangles;i++, element3i += 3)
 926                 Collision_TraceLineTriangleFloat(trace, linestart, lineend, vertex3f + element3i[0] * 3, vertex3f + element3i[1] * 3, vertex3f + element3i[2] * 3, supercontents, q3surfaceflags, texture);
 927 #else
 928         polyf_brush.numpoints = 3;
 929         polyf_brush.numplanes = 5;
 930         polyf_brush.points = polyf_points;
 931         polyf_brush.planes = polyf_planes;
 932         polyf_brush.supercontents = supercontents;
 933         for (i = 0;i < polyf_brush.numplanes;i++)
 934         {
 935                 polyf_brush.planes[i].supercontents = supercontents;
 936                 polyf_brush.planes[i].q3surfaceflags = q3surfaceflags;
 937                 polyf_brush.planes[i].texture = texture;
 938         }
 939         for (i = 0;i < numtriangles;i++, element3i += 3)
 940         {
 941                 float facemins[3], facemaxs[3];
 942                 VectorCopy(vertex3f + element3i[0] * 3, polyf_points[0].v);
 943                 VectorCopy(vertex3f + element3i[1] * 3, polyf_points[1].v);
 944                 VectorCopy(vertex3f + element3i[2] * 3, polyf_points[2].v);
 945                 Collision_SnapCopyPoints(numpoints, polyf_points, polyf_points, COLLISION_SNAPSCALE, COLLISION_SNAP);
 946                 facemins[0] = min(polyf_points[0].v[0], min(polyf_points[1].v[0], polyf_points[2].v[0]));
 947                 facemins[1] = min(polyf_points[0].v[1], min(polyf_points[1].v[1], polyf_points[2].v[1]));
 948                 facemins[2] = min(polyf_points[0].v[2], min(polyf_points[1].v[2], polyf_points[2].v[2]));
 949                 facemaxs[0] = max(polyf_points[0].v[0], max(polyf_points[1].v[0], polyf_points[2].v[0]));
 950                 facemaxs[1] = max(polyf_points[0].v[1], max(polyf_points[1].v[1], polyf_points[2].v[1]));
 951                 facemaxs[2] = max(polyf_points[0].v[2], max(polyf_points[1].v[2], polyf_points[2].v[2]));
 952                 if (BoxesOverlap(segmentmins, segmentmaxs, facemins, facemaxs))
 953                 {
 954                         Collision_CalcPlanesForPolygonBrushFloat(&polyf_brush);
 955                         //Collision_PrintBrushAsQHull(&polyf_brush, "polyf_brush");
 956                         Collision_TraceLineBrushFloat(trace, linestart, lineend, &polyf_brush, &polyf_brush);
 957                 }
 958         }
 959 #endif
 960 }
 961
 962
 963 static colpointf_t polyf_pointsstart[256], polyf_pointsend[256];
 964 static colplanef_t polyf_planesstart[256 + 2], polyf_planesend[256 + 2];
 965 static colbrushf_t polyf_brushstart, polyf_brushend;
 966
 967 void Collision_TraceBrushPolygonTransformFloat(trace_t *trace, const colbrushf_t *thisbrush_start, const colbrushf_t *thisbrush_end, int numpoints, const float *points, const matrix4x4_t *polygonmatrixstart, const matrix4x4_t *polygonmatrixend, int supercontents, int q3surfaceflags, texture_t *texture)
 968 {
 969         int i;
 970         if (numpoints > 256)
 971         {
 972                 Con_Print("Polygon with more than 256 points not supported yet (fixme!)\n");
 973                 return;
 974         }
 975         polyf_brushstart.numpoints = numpoints;
 976         polyf_brushstart.numplanes = numpoints + 2;
 977         polyf_brushstart.points = polyf_pointsstart;//(colpointf_t *)points;
 978         polyf_brushstart.planes = polyf_planesstart;
 979         polyf_brushstart.supercontents = supercontents;
 980         for (i = 0;i < numpoints;i++)
 981                 Matrix4x4_Transform(polygonmatrixstart, points + i * 3, polyf_brushstart.points[i].v);
 982         polyf_brushend.numpoints = numpoints;
 983         polyf_brushend.numplanes = numpoints + 2;
 984         polyf_brushend.points = polyf_pointsend;//(colpointf_t *)points;
 985         polyf_brushend.planes = polyf_planesend;
 986         polyf_brushend.supercontents = supercontents;
 987         for (i = 0;i < numpoints;i++)
 988                 Matrix4x4_Transform(polygonmatrixend, points + i * 3, polyf_brushend.points[i].v);
 989         for (i = 0;i < polyf_brushstart.numplanes;i++)
 990         {
 991                 polyf_brushstart.planes[i].q3surfaceflags = q3surfaceflags;
 992                 polyf_brushstart.planes[i].texture = texture;
 993         }
 994         Collision_SnapCopyPoints(numpoints, polyf_pointsstart, polyf_pointsstart, COLLISION_SNAPSCALE, COLLISION_SNAP);
 995         Collision_SnapCopyPoints(numpoints, polyf_pointsend, polyf_pointsend, COLLISION_SNAPSCALE, COLLISION_SNAP);
 996         Collision_CalcPlanesForPolygonBrushFloat(&polyf_brushstart);
 997         Collision_CalcPlanesForPolygonBrushFloat(&polyf_brushend);
 998
 999         //Collision_PrintBrushAsQHull(&polyf_brushstart, "polyf_brushstart");
1000         //Collision_PrintBrushAsQHull(&polyf_brushend, "polyf_brushend");
1001
1002         Collision_TraceBrushBrushFloat(trace, thisbrush_start, thisbrush_end, &polyf_brushstart, &polyf_brushend);
1003 }
1004
1005
1006
1007 #define MAX_BRUSHFORBOX 16
1008 static int brushforbox_index = 0;
1009 static colpointf_t brushforbox_point[MAX_BRUSHFORBOX*8];
1010 static colplanef_t brushforbox_plane[MAX_BRUSHFORBOX*6];
1011 static colbrushf_t brushforbox_brush[MAX_BRUSHFORBOX];
1012 static colbrushf_t brushforpoint_brush[MAX_BRUSHFORBOX];
1013
1014 void Collision_InitBrushForBox(void)
1015 {
1016         int i;
1017         for (i = 0;i < MAX_BRUSHFORBOX;i++)
1018         {
1019                 brushforbox_brush[i].numpoints = 8;
1020                 brushforbox_brush[i].numplanes = 6;
1021                 brushforbox_brush[i].points = brushforbox_point + i * 8;
1022                 brushforbox_brush[i].planes = brushforbox_plane + i * 6;
1023                 brushforpoint_brush[i].numpoints = 1;
1024                 brushforpoint_brush[i].numplanes = 0;
1025                 brushforpoint_brush[i].points = brushforbox_point + i * 8;
1026                 brushforpoint_brush[i].planes = brushforbox_plane + i * 6;
1027         }
1028 }
1029
1030 colbrushf_t *Collision_BrushForBox(const matrix4x4_t *matrix, const vec3_t mins, const vec3_t maxs, int supercontents, int q3surfaceflags, texture_t *texture)
1031 {
1032         int i, j;
1033         vec3_t v;
1034         colbrushf_t *brush;
1035         if (brushforbox_brush[0].numpoints == 0)
1036                 Collision_InitBrushForBox();
1037         // FIXME: these probably don't actually need to be normalized if the collision code does not care
1038         if (VectorCompare(mins, maxs))
1039         {
1040                 // point brush
1041                 brush = brushforpoint_brush + ((brushforbox_index++) % MAX_BRUSHFORBOX);
1042                 VectorCopy(mins, brush->points->v);
1043         }
1044         else
1045         {
1046                 brush = brushforbox_brush + ((brushforbox_index++) % MAX_BRUSHFORBOX);
1047                 // FIXME: optimize
1048                 for (i = 0;i < 8;i++)
1049                 {
1050                         v[0] = i & 1 ? maxs[0] : mins[0];
1051                         v[1] = i & 2 ? maxs[1] : mins[1];
1052                         v[2] = i & 4 ? maxs[2] : mins[2];
1053                         Matrix4x4_Transform(matrix, v, brush->points[i].v);
1054                 }
1055                 // FIXME: optimize!
1056                 for (i = 0;i < 6;i++)
1057                 {
1058                         VectorClear(v);
1059                         v[i >> 1] = i & 1 ? 1 : -1;
1060                         Matrix4x4_Transform3x3(matrix, v, brush->planes[i].normal);
1061                         VectorNormalize(brush->planes[i].normal);
1062                 }
1063         }
1064         brush->supercontents = supercontents;
1065         for (j = 0;j < brush->numplanes;j++)
1066         {
1067                 brush->planes[j].q3surfaceflags = q3surfaceflags;
1068                 brush->planes[j].texture = texture;
1069                 brush->planes[j].dist = furthestplanedist_float(brush->planes[j].normal, brush->points, brush->numpoints);
1070         }
1071         VectorCopy(brush->points[0].v, brush->mins);
1072         VectorCopy(brush->points[0].v, brush->maxs);
1073         for (j = 1;j < brush->numpoints;j++)
1074         {
1075                 brush->mins[0] = min(brush->mins[0], brush->points[j].v[0]);
1076                 brush->mins[1] = min(brush->mins[1], brush->points[j].v[1]);
1077                 brush->mins[2] = min(brush->mins[2], brush->points[j].v[2]);
1078                 brush->maxs[0] = max(brush->maxs[0], brush->points[j].v[0]);
1079                 brush->maxs[1] = max(brush->maxs[1], brush->points[j].v[1]);
1080                 brush->maxs[2] = max(brush->maxs[2], brush->points[j].v[2]);
1081         }
1082         brush->mins[0] -= 1;
1083         brush->mins[1] -= 1;
1084         brush->mins[2] -= 1;
1085         brush->maxs[0] += 1;
1086         brush->maxs[1] += 1;
1087         brush->maxs[2] += 1;
1088         Collision_ValidateBrush(brush);
1089         return brush;
1090 }
1091
1092 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)
1093 {
1094         colbrushf_t *boxbrush, *thisbrush_start, *thisbrush_end;
1095         vec3_t startmins, startmaxs, endmins, endmaxs;
1096
1097         // create brushes for the collision
1098         VectorAdd(start, mins, startmins);
1099         VectorAdd(start, maxs, startmaxs);
1100         VectorAdd(end, mins, endmins);
1101         VectorAdd(end, maxs, endmaxs);
1102         boxbrush = Collision_BrushForBox(&identitymatrix, cmins, cmaxs, supercontents, q3surfaceflags, texture);
1103         thisbrush_start = Collision_BrushForBox(&identitymatrix, startmins, startmaxs, 0, 0, NULL);
1104         thisbrush_end = Collision_BrushForBox(&identitymatrix, endmins, endmaxs, 0, 0, NULL);
1105
1106         memset(trace, 0, sizeof(trace_t));
1107         trace->hitsupercontentsmask = hitsupercontentsmask;
1108         trace->fraction = 1;
1109         trace->realfraction = 1;
1110         trace->allsolid = true;
1111         Collision_TraceBrushBrushFloat(trace, thisbrush_start, thisbrush_end, boxbrush, boxbrush);
1112 }
1113
1114 //pseudocode for detecting line/sphere overlap without calculating an impact point
1115 //linesphereorigin = sphereorigin - linestart;linediff = lineend - linestart;linespherefrac = DotProduct(linesphereorigin, linediff) / DotProduct(linediff, linediff);return VectorLength2(linesphereorigin - bound(0, linespherefrac, 1) * linediff) >= sphereradius*sphereradius;
1116
1117 // LordHavoc: currently unused, but tested
1118 // note: this can be used for tracing a moving sphere vs a stationary sphere,
1119 // by simply adding the moving sphere's radius to the sphereradius parameter,
1120 // all the results are correct (impactpoint, impactnormal, and fraction)
1121 float Collision_ClipTrace_Line_Sphere(double *linestart, double *lineend, double *sphereorigin, double sphereradius, double *impactpoint, double *impactnormal)
1122 {
1123         double dir[3], scale, v[3], deviationdist, impactdist, linelength;
1124         // make sure the impactpoint and impactnormal are valid even if there is
1125         // no collision
1126         VectorCopy(lineend, impactpoint);
1127         VectorClear(impactnormal);
1128         // calculate line direction
1129         VectorSubtract(lineend, linestart, dir);
1130         // normalize direction
1131         linelength = VectorLength(dir);
1132         if (linelength)
1133         {
1134                 scale = 1.0 / linelength;
1135                 VectorScale(dir, scale, dir);
1136         }
1137         // this dotproduct calculates the distance along the line at which the
1138         // sphere origin is (nearest point to the sphere origin on the line)
1139         impactdist = DotProduct(sphereorigin, dir) - DotProduct(linestart, dir);
1140         // calculate point on line at that distance, and subtract the
1141         // sphereorigin from it, so we have a vector to measure for the distance
1142         // of the line from the sphereorigin (deviation, how off-center it is)
1143         VectorMA(linestart, impactdist, dir, v);
1144         VectorSubtract(v, sphereorigin, v);
1145         deviationdist = VectorLength2(v);
1146         // if outside the radius, it's a miss for sure
1147         // (we do this comparison using squared radius to avoid a sqrt)
1148         if (deviationdist > sphereradius*sphereradius)
1149                 return 1; // miss (off to the side)
1150         // nudge back to find the correct impact distance
1151         impactdist += deviationdist - sphereradius;
1152         if (impactdist >= linelength)
1153                 return 1; // miss (not close enough)
1154         if (impactdist < 0)
1155                 return 1; // miss (linestart is past or inside sphere)
1156         // calculate new impactpoint
1157         VectorMA(linestart, impactdist, dir, impactpoint);
1158         // calculate impactnormal (surface normal at point of impact)
1159         VectorSubtract(impactpoint, sphereorigin, impactnormal);
1160         // normalize impactnormal
1161         VectorNormalize(impactnormal);
1162         // return fraction of movement distance
1163         return impactdist / linelength;
1164 }
1165
1166 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)
1167 {
1168 #if 1
1169         // more optimized
1170         float d1, d2, d, f, impact[3], edgenormal[3], faceplanenormal[3], faceplanedist, faceplanenormallength2, edge01[3], edge21[3], edge02[3];
1171
1172         // this function executes:
1173         // 32 ops when line starts behind triangle
1174         // 38 ops when line ends infront of triangle
1175         // 43 ops when line fraction is already closer than this triangle
1176         // 72 ops when line is outside edge 01
1177         // 92 ops when line is outside edge 21
1178         // 115 ops when line is outside edge 02
1179         // 123 ops when line impacts triangle and updates trace results
1180
1181         // this code is designed for clockwise triangles, conversion to
1182         // counterclockwise would require swapping some things around...
1183         // it is easier to simply swap the point0 and point2 parameters to this
1184         // function when calling it than it is to rewire the internals.
1185
1186         // calculate the faceplanenormal of the triangle, this represents the front side
1187         // 15 ops
1188         VectorSubtract(point0, point1, edge01);
1189         VectorSubtract(point2, point1, edge21);
1190         CrossProduct(edge01, edge21, faceplanenormal);
1191         // there's no point in processing a degenerate triangle (GIGO - Garbage In, Garbage Out)
1192         // 6 ops
1193         faceplanenormallength2 = DotProduct(faceplanenormal, faceplanenormal);
1194         if (faceplanenormallength2 < 0.0001f)
1195                 return;
1196         // calculate the distance
1197         // 5 ops
1198         faceplanedist = DotProduct(point0, faceplanenormal);
1199
1200         // if start point is on the back side there is no collision
1201         // (we don't care about traces going through the triangle the wrong way)
1202
1203         // calculate the start distance
1204         // 6 ops
1205         d1 = DotProduct(faceplanenormal, linestart);
1206         if (d1 <= faceplanedist)
1207                 return;
1208
1209         // calculate the end distance
1210         // 6 ops
1211         d2 = DotProduct(faceplanenormal, lineend);
1212         // if both are in front, there is no collision
1213         if (d2 >= faceplanedist)
1214                 return;
1215
1216         // from here on we know d1 is >= 0 and d2 is < 0
1217         // this means the line starts infront and ends behind, passing through it
1218
1219         // calculate the recipricol of the distance delta,
1220         // so we can use it multiple times cheaply (instead of division)
1221         // 2 ops
1222         d = 1.0f / (d1 - d2);
1223         // calculate the impact fraction by taking the start distance (> 0)
1224         // and subtracting the face plane distance (this is the distance of the
1225         // triangle along that same normal)
1226         // then multiply by the recipricol distance delta
1227         // 2 ops
1228         f = (d1 - faceplanedist) * d;
1229         // skip out if this impact is further away than previous ones
1230         // 1 ops
1231         if (f > trace->realfraction)
1232                 return;
1233         // calculate the perfect impact point for classification of insidedness
1234         // 9 ops
1235         impact[0] = linestart[0] + f * (lineend[0] - linestart[0]);
1236         impact[1] = linestart[1] + f * (lineend[1] - linestart[1]);
1237         impact[2] = linestart[2] + f * (lineend[2] - linestart[2]);
1238
1239         // calculate the edge normal and reject if impact is outside triangle
1240         // (an edge normal faces away from the triangle, to get the desired normal
1241         //  a crossproduct with the faceplanenormal is used, and because of the way
1242         // the insidedness comparison is written it does not need to be normalized)
1243
1244         // first use the two edges from the triangle plane math
1245         // the other edge only gets calculated if the point survives that long
1246
1247         // 20 ops
1248         CrossProduct(edge01, faceplanenormal, edgenormal);
1249         if (DotProduct(impact, edgenormal) > DotProduct(point1, edgenormal))
1250                 return;
1251
1252         // 20 ops
1253         CrossProduct(faceplanenormal, edge21, edgenormal);
1254         if (DotProduct(impact, edgenormal) > DotProduct(point2, edgenormal))
1255                 return;
1256
1257         // 23 ops
1258         VectorSubtract(point0, point2, edge02);
1259         CrossProduct(faceplanenormal, edge02, edgenormal);
1260         if (DotProduct(impact, edgenormal) > DotProduct(point0, edgenormal))
1261                 return;
1262
1263         // 8 ops (rare)
1264
1265         // store the new trace fraction
1266         trace->realfraction = f;
1267
1268         // calculate a nudged fraction to keep it out of the surface
1269         // (the main fraction remains perfect)
1270         trace->fraction = f - collision_impactnudge.value * d;
1271
1272         if (collision_prefernudgedfraction.integer)
1273                 trace->realfraction = trace->fraction;
1274
1275         // store the new trace plane (because collisions only happen from
1276         // the front this is always simply the triangle normal, never flipped)
1277         d = 1.0 / sqrt(faceplanenormallength2);
1278         VectorScale(faceplanenormal, d, trace->plane.normal);
1279         trace->plane.dist = faceplanedist * d;
1280
1281         trace->hitsupercontents = supercontents;
1282         trace->hitq3surfaceflags = q3surfaceflags;
1283         trace->hittexture = texture;
1284 #else
1285         float d1, d2, d, f, fnudged, impact[3], edgenormal[3], faceplanenormal[3], faceplanedist, edge[3];
1286
1287         // this code is designed for clockwise triangles, conversion to
1288         // counterclockwise would require swapping some things around...
1289         // it is easier to simply swap the point0 and point2 parameters to this
1290         // function when calling it than it is to rewire the internals.
1291
1292         // calculate the unnormalized faceplanenormal of the triangle,
1293         // this represents the front side
1294         TriangleNormal(point0, point1, point2, faceplanenormal);
1295         // there's no point in processing a degenerate triangle
1296         // (GIGO - Garbage In, Garbage Out)
1297         if (DotProduct(faceplanenormal, faceplanenormal) < 0.0001f)
1298                 return;
1299         // calculate the unnormalized distance
1300         faceplanedist = DotProduct(point0, faceplanenormal);
1301
1302         // calculate the unnormalized start distance
1303         d1 = DotProduct(faceplanenormal, linestart) - faceplanedist;
1304         // if start point is on the back side there is no collision
1305         // (we don't care about traces going through the triangle the wrong way)
1306         if (d1 <= 0)
1307                 return;
1308
1309         // calculate the unnormalized end distance
1310         d2 = DotProduct(faceplanenormal, lineend) - faceplanedist;
1311         // if both are in front, there is no collision
1312         if (d2 >= 0)
1313                 return;
1314
1315         // from here on we know d1 is >= 0 and d2 is < 0
1316         // this means the line starts infront and ends behind, passing through it
1317
1318         // calculate the recipricol of the distance delta,
1319         // so we can use it multiple times cheaply (instead of division)
1320         d = 1.0f / (d1 - d2);
1321         // calculate the impact fraction by taking the start distance (> 0)
1322         // and subtracting the face plane distance (this is the distance of the
1323         // triangle along that same normal)
1324         // then multiply by the recipricol distance delta
1325         f = d1 * d;
1326         // skip out if this impact is further away than previous ones
1327         if (f > trace->realfraction)
1328                 return;
1329         // calculate the perfect impact point for classification of insidedness
1330         impact[0] = linestart[0] + f * (lineend[0] - linestart[0]);
1331         impact[1] = linestart[1] + f * (lineend[1] - linestart[1]);
1332         impact[2] = linestart[2] + f * (lineend[2] - linestart[2]);
1333
1334         // calculate the edge normal and reject if impact is outside triangle
1335         // (an edge normal faces away from the triangle, to get the desired normal
1336         //  a crossproduct with the faceplanenormal is used, and because of the way
1337         // the insidedness comparison is written it does not need to be normalized)
1338
1339         VectorSubtract(point2, point0, edge);
1340         CrossProduct(edge, faceplanenormal, edgenormal);
1341         if (DotProduct(impact, edgenormal) > DotProduct(point0, edgenormal))
1342                 return;
1343
1344         VectorSubtract(point0, point1, edge);
1345         CrossProduct(edge, faceplanenormal, edgenormal);
1346         if (DotProduct(impact, edgenormal) > DotProduct(point1, edgenormal))
1347                 return;
1348
1349         VectorSubtract(point1, point2, edge);
1350         CrossProduct(edge, faceplanenormal, edgenormal);
1351         if (DotProduct(impact, edgenormal) > DotProduct(point2, edgenormal))
1352                 return;
1353
1354         // store the new trace fraction
1355         trace->realfraction = bound(0, f, 1);
1356
1357         // store the new trace plane (because collisions only happen from
1358         // the front this is always simply the triangle normal, never flipped)
1359         VectorNormalize(faceplanenormal);
1360         VectorCopy(faceplanenormal, trace->plane.normal);
1361         trace->plane.dist = DotProduct(point0, faceplanenormal);
1362
1363         // calculate the normalized start and end distances
1364         d1 = DotProduct(trace->plane.normal, linestart) - trace->plane.dist;
1365         d2 = DotProduct(trace->plane.normal, lineend) - trace->plane.dist;
1366
1367         // calculate a nudged fraction to keep it out of the surface
1368         // (the main fraction remains perfect)
1369         fnudged = (d1 - collision_impactnudge.value) / (d1 - d2);
1370         trace->fraction = bound(0, fnudged, 1);
1371
1372         // store the new trace endpos
1373         // not needed, it's calculated later when the trace is finished
1374         //trace->endpos[0] = linestart[0] + fnudged * (lineend[0] - linestart[0]);
1375         //trace->endpos[1] = linestart[1] + fnudged * (lineend[1] - linestart[1]);
1376         //trace->endpos[2] = linestart[2] + fnudged * (lineend[2] - linestart[2]);
1377         trace->hitsupercontents = supercontents;
1378         trace->hitq3surfaceflags = q3surfaceflags;
1379         trace->hittexture = texture;
1380 #endif
1381 }
1382
1383 typedef struct colbspnode_s
1384 {
1385         mplane_t plane;
1386         struct colbspnode_s *children[2];
1387         // the node is reallocated or split if max is reached
1388         int numcolbrushf;
1389         int maxcolbrushf;
1390         colbrushf_t **colbrushflist;
1391         //int numcolbrushd;
1392         //int maxcolbrushd;
1393         //colbrushd_t **colbrushdlist;
1394 }
1395 colbspnode_t;
1396
1397 typedef struct colbsp_s
1398 {
1399         mempool_t *mempool;
1400         colbspnode_t *nodes;
1401 }
1402 colbsp_t;
1403
1404 colbsp_t *Collision_CreateCollisionBSP(mempool_t *mempool)
1405 {
1406         colbsp_t *bsp;
1407         bsp = (colbsp_t *)Mem_Alloc(mempool, sizeof(colbsp_t));
1408         bsp->mempool = mempool;
1409         bsp->nodes = (colbspnode_t *)Mem_Alloc(bsp->mempool, sizeof(colbspnode_t));
1410         return bsp;
1411 }
1412
1413 void Collision_FreeCollisionBSPNode(colbspnode_t *node)
1414 {
1415         if (node->children[0])
1416                 Collision_FreeCollisionBSPNode(node->children[0]);
1417         if (node->children[1])
1418                 Collision_FreeCollisionBSPNode(node->children[1]);
1419         while (--node->numcolbrushf)
1420                 Mem_Free(node->colbrushflist[node->numcolbrushf]);
1421         //while (--node->numcolbrushd)
1422         //      Mem_Free(node->colbrushdlist[node->numcolbrushd]);
1423         Mem_Free(node);
1424 }
1425
1426 void Collision_FreeCollisionBSP(colbsp_t *bsp)
1427 {
1428         Collision_FreeCollisionBSPNode(bsp->nodes);
1429         Mem_Free(bsp);
1430 }
1431
1432 void Collision_BoundingBoxOfBrushTraceSegment(const colbrushf_t *start, const colbrushf_t *end, vec3_t mins, vec3_t maxs, float startfrac, float endfrac)
1433 {
1434         int i;
1435         colpointf_t *ps, *pe;
1436         float tempstart[3], tempend[3];
1437         VectorLerp(start->points[0].v, startfrac, end->points[0].v, mins);
1438         VectorCopy(mins, maxs);
1439         for (i = 0, ps = start->points, pe = end->points;i < start->numpoints;i++, ps++, pe++)
1440         {
1441                 VectorLerp(ps->v, startfrac, pe->v, tempstart);
1442                 VectorLerp(ps->v, endfrac, pe->v, tempend);
1443                 mins[0] = min(mins[0], min(tempstart[0], tempend[0]));
1444                 mins[1] = min(mins[1], min(tempstart[1], tempend[1]));
1445                 mins[2] = min(mins[2], min(tempstart[2], tempend[2]));
1446                 maxs[0] = min(maxs[0], min(tempstart[0], tempend[0]));
1447                 maxs[1] = min(maxs[1], min(tempstart[1], tempend[1]));
1448                 maxs[2] = min(maxs[2], min(tempstart[2], tempend[2]));
1449         }
1450         mins[0] -= 1;
1451         mins[1] -= 1;
1452         mins[2] -= 1;
1453         maxs[0] += 1;
1454         maxs[1] += 1;
1455         maxs[2] += 1;
1456 }
1457