portals.c

   1
   2 #include "quakedef.h"
   3
   4 #define MAXRECURSIVEPORTALPLANES 1024
   5 #define MAXRECURSIVEPORTALS 256
   6
   7 static tinyplane_t portalplanes[MAXRECURSIVEPORTALPLANES];
   8 static int ranoutofportalplanes;
   9 static int ranoutofportals;
  10 static float portaltemppoints[2][256][3];
  11 static float portaltemppoints2[256][3];
  12 static int portal_markid = 0;
  13 static float boxpoints[4*3];
  14
  15 int Portal_ClipPolygonToPlane(float *in, float *out, int inpoints, int maxoutpoints, tinyplane_t *p)
  16 {
  17         int i, outpoints, prevside, side;
  18         float *prevpoint, prevdist, dist, dot;
  19
  20         if (inpoints < 3)
  21                 return inpoints;
  22         // begin with the last point, then enter the loop with the first point as current
  23         prevpoint = in + 3 * (inpoints - 1);
  24         prevdist = DotProduct(prevpoint, p->normal) - p->dist;
  25         prevside = prevdist >= 0 ? SIDE_FRONT : SIDE_BACK;
  26         i = 0;
  27         outpoints = 0;
  28         goto begin;
  29         for (;i < inpoints;i++)
  30         {
  31                 prevpoint = in;
  32                 prevdist = dist;
  33                 prevside = side;
  34                 in += 3;
  35
  36 begin:
  37                 dist = DotProduct(in, p->normal) - p->dist;
  38                 side = dist >= 0 ? SIDE_FRONT : SIDE_BACK;
  39
  40                 if (prevside == SIDE_FRONT)
  41                 {
  42                         if (outpoints >= maxoutpoints)
  43                                 return -1;
  44                         VectorCopy(prevpoint, out);
  45                         out += 3;
  46                         outpoints++;
  47                         if (side == SIDE_FRONT)
  48                                 continue;
  49                 }
  50                 else if (side == SIDE_BACK)
  51                         continue;
  52
  53                 // generate a split point
  54                 if (outpoints >= maxoutpoints)
  55                         return -1;
  56                 dot = prevdist / (prevdist - dist);
  57                 out[0] = prevpoint[0] + dot * (in[0] - prevpoint[0]);
  58                 out[1] = prevpoint[1] + dot * (in[1] - prevpoint[1]);
  59                 out[2] = prevpoint[2] + dot * (in[2] - prevpoint[2]);
  60                 out += 3;
  61                 outpoints++;
  62         }
  63
  64         return outpoints;
  65 }
  66
  67
  68 int Portal_PortalThroughPortalPlanes(tinyplane_t *clipplanes, int clipnumplanes, float *targpoints, int targnumpoints, float *out, int maxpoints)
  69 {
  70         int numpoints, i;
  71         if (targnumpoints < 3)
  72                 return targnumpoints;
  73         if (maxpoints < 3)
  74                 return -1;
  75         numpoints = targnumpoints;
  76         memcpy(&portaltemppoints[0][0][0], targpoints, numpoints * 3 * sizeof(float));
  77         for (i = 0;i < clipnumplanes;i++)
  78         {
  79                 numpoints = Portal_ClipPolygonToPlane(&portaltemppoints[0][0][0], &portaltemppoints[1][0][0], numpoints, 256, clipplanes + i);
  80                 if (numpoints < 3)
  81                         return numpoints;
  82                 memcpy(&portaltemppoints[0][0][0], &portaltemppoints[1][0][0], numpoints * 3 * sizeof(float));
  83         }
  84         if (numpoints > maxpoints)
  85                 return -1;
  86         memcpy(out, &portaltemppoints[0][0][0], numpoints * 3 * sizeof(float));
  87         return numpoints;
  88 }
  89
  90 int Portal_RecursiveFlowSearch (mleaf_t *leaf, vec3_t eye, int firstclipplane, int numclipplanes)
  91 {
  92         mportal_t *p;
  93         int newpoints, i, prev;
  94         vec3_t center, v1, v2;
  95         tinyplane_t *newplanes;
  96
  97         if (leaf->portalmarkid == portal_markid)
  98                 return true;
  99
 100         // follow portals into other leafs
 101         for (p = leaf->portals;p;p = p->next)
 102         {
 103                 // only flow through portals facing away from the viewer
 104                 if (PlaneDiff(eye, (&p->plane)) < 0)
 105                 {
 106                         newpoints = Portal_PortalThroughPortalPlanes(&portalplanes[firstclipplane], numclipplanes, (float *) p->points, p->numpoints, &portaltemppoints2[0][0], 256);
 107                         if (newpoints < 3)
 108                                 continue;
 109                         else if (firstclipplane + numclipplanes + newpoints > MAXRECURSIVEPORTALPLANES)
 110                                 ranoutofportalplanes = true;
 111                         else
 112                         {
 113                                 // find the center by averaging
 114                                 VectorClear(center);
 115                                 for (i = 0;i < newpoints;i++)
 116                                         VectorAdd(center, portaltemppoints2[i], center);
 117                                 // ixtable is a 1.0f / N table
 118                                 VectorScale(center, ixtable[newpoints], center);
 119                                 // calculate the planes, and make sure the polygon can see it's own center
 120                                 newplanes = &portalplanes[firstclipplane + numclipplanes];
 121                                 for (prev = newpoints - 1, i = 0;i < newpoints;prev = i, i++)
 122                                 {
 123                                         VectorSubtract(eye, portaltemppoints2[i], v1);
 124                                         VectorSubtract(portaltemppoints2[prev], portaltemppoints2[i], v2);
 125                                         CrossProduct(v1, v2, newplanes[i].normal);
 126                                         VectorNormalizeFast(newplanes[i].normal);
 127                                         newplanes[i].dist = DotProduct(eye, newplanes[i].normal);
 128                                         if (DotProduct(newplanes[i].normal, center) <= newplanes[i].dist)
 129                                         {
 130                                                 // polygon can't see it's own center, discard and use parent portal
 131                                                 break;
 132                                         }
 133                                 }
 134                                 if (i == newpoints)
 135                                 {
 136                                         if (Portal_RecursiveFlowSearch(p->past, eye, firstclipplane + numclipplanes, newpoints))
 137                                                 return true;
 138                                 }
 139                                 else
 140                                 {
 141                                         if (Portal_RecursiveFlowSearch(p->past, eye, firstclipplane, numclipplanes))
 142                                                 return true;
 143                                 }
 144                         }
 145                 }
 146         }
 147
 148         return false;
 149 }
 150
 151 void Portal_PolygonRecursiveMarkLeafs(mnode_t *node, float *polypoints, int numpoints)
 152 {
 153         int i, front;
 154         float *p;
 155
 156 loc0:
 157         if (node->contents < 0)
 158         {
 159                 ((mleaf_t *)node)->portalmarkid = portal_markid;
 160                 return;
 161         }
 162
 163         front = 0;
 164         for (i = 0, p = polypoints;i < numpoints;i++, p += 3)
 165         {
 166                 if (DotProduct(p, node->plane->normal) > node->plane->dist)
 167                         front++;
 168         }
 169         if (front > 0)
 170         {
 171                 if (front == numpoints)
 172                 {
 173                         node = node->children[0];
 174                         goto loc0;
 175                 }
 176                 else
 177                         Portal_PolygonRecursiveMarkLeafs(node->children[0], polypoints, numpoints);
 178         }
 179         node = node->children[1];
 180         goto loc0;
 181 }
 182
 183 int Portal_CheckPolygon(model_t *model, vec3_t eye, float *polypoints, int numpoints)
 184 {
 185         int i, prev, returnvalue;
 186         mleaf_t *eyeleaf;
 187         vec3_t center, v1, v2;
 188
 189         // if there is no model, it can not block visibility
 190         if (model == NULL)
 191                 return true;
 192
 193         portal_markid++;
 194
 195         Mod_CheckLoaded(model);
 196         Portal_PolygonRecursiveMarkLeafs(model->nodes, polypoints, numpoints);
 197
 198         eyeleaf = model->PointInLeaf(model, eye);
 199
 200         // find the center by averaging
 201         VectorClear(center);
 202         for (i = 0;i < numpoints;i++)
 203                 VectorAdd(center, (&polypoints[i * 3]), center);
 204         // ixtable is a 1.0f / N table
 205         VectorScale(center, ixtable[numpoints], center);
 206
 207         // calculate the planes, and make sure the polygon can see it's own center
 208         for (prev = numpoints - 1, i = 0;i < numpoints;prev = i, i++)
 209         {
 210                 VectorSubtract(eye, (&polypoints[i * 3]), v1);
 211                 VectorSubtract((&polypoints[prev * 3]), (&polypoints[i * 3]), v2);
 212                 CrossProduct(v1, v2, portalplanes[i].normal);
 213                 VectorNormalizeFast(portalplanes[i].normal);
 214                 portalplanes[i].dist = DotProduct(eye, portalplanes[i].normal);
 215                 if (DotProduct(portalplanes[i].normal, center) <= portalplanes[i].dist)
 216                 {
 217                         // polygon can't see it's own center, discard
 218                         return false;
 219                 }
 220         }
 221
 222         ranoutofportalplanes = false;
 223         ranoutofportals = false;
 224
 225         returnvalue = Portal_RecursiveFlowSearch(eyeleaf, eye, 0, numpoints);
 226
 227         if (ranoutofportalplanes)
 228                 Con_Printf("Portal_RecursiveFlowSearch: ran out of %d plane stack when recursing through portals\n", MAXRECURSIVEPORTALPLANES);
 229         if (ranoutofportals)
 230                 Con_Printf("Portal_RecursiveFlowSearch: ran out of %d portal stack when recursing through portals\n", MAXRECURSIVEPORTALS);
 231
 232         return returnvalue;
 233 }
 234
 235 #define Portal_MinsBoxPolygon(axis, axisvalue, x1, y1, z1, x2, y2, z2, x3, y3, z3, x4, y4, z4) \
 236 {\
 237         if (eye[(axis)] < ((axisvalue) - 0.5f))\
 238         {\
 239                 boxpoints[ 0] = x1;boxpoints[ 1] = y1;boxpoints[ 2] = z1;\
 240                 boxpoints[ 3] = x2;boxpoints[ 4] = y2;boxpoints[ 5] = z2;\
 241                 boxpoints[ 6] = x3;boxpoints[ 7] = y3;boxpoints[ 8] = z3;\
 242                 boxpoints[ 9] = x4;boxpoints[10] = y4;boxpoints[11] = z4;\
 243                 if (Portal_CheckPolygon(model, eye, boxpoints, 4))\
 244                         return true;\
 245         }\
 246 }
 247
 248 #define Portal_MaxsBoxPolygon(axis, axisvalue, x1, y1, z1, x2, y2, z2, x3, y3, z3, x4, y4, z4) \
 249 {\
 250         if (eye[(axis)] > ((axisvalue) + 0.5f))\
 251         {\
 252                 boxpoints[ 0] = x1;boxpoints[ 1] = y1;boxpoints[ 2] = z1;\
 253                 boxpoints[ 3] = x2;boxpoints[ 4] = y2;boxpoints[ 5] = z2;\
 254                 boxpoints[ 6] = x3;boxpoints[ 7] = y3;boxpoints[ 8] = z3;\
 255                 boxpoints[ 9] = x4;boxpoints[10] = y4;boxpoints[11] = z4;\
 256                 if (Portal_CheckPolygon(model, eye, boxpoints, 4))\
 257                         return true;\
 258         }\
 259 }
 260
 261 int Portal_CheckBox(model_t *model, vec3_t eye, vec3_t a, vec3_t b)
 262 {
 263         if (eye[0] >= (a[0] - 1.0f) && eye[0] < (b[0] + 1.0f)
 264          && eye[1] >= (a[1] - 1.0f) && eye[1] < (b[1] + 1.0f)
 265          && eye[2] >= (a[2] - 1.0f) && eye[2] < (b[2] + 1.0f))
 266                 return true;
 267
 268         Portal_MinsBoxPolygon
 269         (
 270                 0, a[0],
 271                 a[0], a[1], a[2],
 272                 a[0], b[1], a[2],
 273                 a[0], b[1], b[2],
 274                 a[0], a[1], b[2]
 275         );
 276         Portal_MaxsBoxPolygon
 277         (
 278                 0, b[0],
 279                 b[0], b[1], a[2],
 280                 b[0], a[1], a[2],
 281                 b[0], a[1], b[2],
 282                 b[0], b[1], b[2]
 283         );
 284         Portal_MinsBoxPolygon
 285         (
 286                 1, a[1],
 287                 b[0], a[1], a[2],
 288                 a[0], a[1], a[2],
 289                 a[0], a[1], b[2],
 290                 b[0], a[1], b[2]
 291         );
 292         Portal_MaxsBoxPolygon
 293         (
 294                 1, b[1],
 295                 a[0], b[1], a[2],
 296                 b[0], b[1], a[2],
 297                 b[0], b[1], b[2],
 298                 a[0], b[1], b[2]
 299         );
 300         Portal_MinsBoxPolygon
 301         (
 302                 2, a[2],
 303                 a[0], a[1], a[2],
 304                 b[0], a[1], a[2],
 305                 b[0], b[1], a[2],
 306                 a[0], b[1], a[2]
 307         );
 308         Portal_MaxsBoxPolygon
 309         (
 310                 2, b[2],
 311                 b[0], a[1], b[2],
 312                 a[0], a[1], b[2],
 313                 a[0], b[1], b[2],
 314                 b[0], b[1], b[2]
 315         );
 316
 317         return false;
 318 }
 319
 320 vec3_t trianglepoints[3];
 321
 322 typedef struct portalrecursioninfo_s
 323 {
 324         int exact;
 325         int numfrustumplanes;
 326         float nradius;
 327         qbyte *surfacemark;
 328         qbyte *leafmark;
 329         model_t *model;
 330         vec3_t eye;
 331 }
 332 portalrecursioninfo_t;
 333
 334 void Portal_RecursiveFlow_ExactMarkSurfaces(portalrecursioninfo_t *info, int *mark, int nummarksurfaces, int firstclipplane, int numclipplanes)
 335 {
 336         int i, j, *elements;
 337         msurface_t *surf;
 338         surfmesh_t *surfmesh;
 339         for (i = 0;i < nummarksurfaces;i++, mark++)
 340         {
 341                 if (!info->surfacemark[*mark])
 342                 {
 343                         surf = info->model->surfaces + *mark;
 344                         if (surf->poly_numverts)
 345                         {
 346                                 if (surf->flags & SURF_PLANEBACK)
 347                                 {
 348                                         if (DotProduct(info->eye, surf->plane->normal) > surf->plane->dist)
 349                                                 continue;
 350                                 }
 351                                 else
 352                                 {
 353                                         if (DotProduct(info->eye, surf->plane->normal) < surf->plane->dist)
 354                                                 continue;
 355                                 }
 356                                 if (Portal_PortalThroughPortalPlanes(&portalplanes[firstclipplane], numclipplanes, surf->poly_verts, surf->poly_numverts, &portaltemppoints2[0][0], 256) < 3)
 357                                         continue;
 358                         }
 359                         else
 360                         {
 361                                 for (surfmesh = surf->mesh;surfmesh;surfmesh = surfmesh->chain)
 362                                 {
 363                                         for (j = 0, elements = surfmesh->element3i;j < surfmesh->numtriangles;j++, elements += 3)
 364                                         {
 365                                                 VectorCopy((surfmesh->vertex3f + elements[0] * 3), trianglepoints[0]);
 366                                                 VectorCopy((surfmesh->vertex3f + elements[1] * 3), trianglepoints[1]);
 367                                                 VectorCopy((surfmesh->vertex3f + elements[2] * 3), trianglepoints[2]);
 368                                                 if (PointInfrontOfTriangle(info->eye, trianglepoints[0], trianglepoints[1], trianglepoints[2])
 369                                                  && Portal_PortalThroughPortalPlanes(&portalplanes[firstclipplane], numclipplanes, trianglepoints[0], 3, &portaltemppoints2[0][0], 256) >= 3)
 370                                                         break;
 371                                         }
 372                                         if (j < surfmesh->numtriangles)
 373                                                 break;
 374                                 }
 375                                 if (surfmesh == NULL)
 376                                         continue;
 377                         }
 378                         info->surfacemark[*mark] = true;
 379                 }
 380         }
 381 }
 382
 383 void Portal_RecursiveFlow (portalrecursioninfo_t *info, mleaf_t *leaf, int firstclipplane, int numclipplanes)
 384 {
 385         mportal_t *p;
 386         int newpoints, i, prev;
 387         float dist;
 388         vec3_t center, v1, v2;
 389         tinyplane_t *newplanes;
 390
 391         if (info->leafmark)
 392                 info->leafmark[leaf - info->model->leafs] = true;
 393
 394         // mark surfaces in leaf that can be seen through portal
 395         if (leaf->nummarksurfaces && info->surfacemark)
 396         {
 397                 if (info->exact)
 398                         Portal_RecursiveFlow_ExactMarkSurfaces(info, leaf->firstmarksurface, leaf->nummarksurfaces, firstclipplane, numclipplanes);
 399                 else
 400                         for (i = 0;i < leaf->nummarksurfaces;i++)
 401                                 info->surfacemark[leaf->firstmarksurface[i]] = true;
 402         }
 403
 404         // follow portals into other leafs
 405         for (p = leaf->portals;p;p = p->next)
 406         {
 407                 // only flow through portals facing away from the viewer
 408                 dist = PlaneDiff(info->eye, (&p->plane));
 409                 if (dist < 0 && dist >= info->nradius)
 410                 {
 411                         newpoints = Portal_PortalThroughPortalPlanes(&portalplanes[firstclipplane], numclipplanes, (float *) p->points, p->numpoints, &portaltemppoints2[0][0], 256);
 412                         if (newpoints < 3)
 413                                 continue;
 414                         else if (firstclipplane + numclipplanes + newpoints > MAXRECURSIVEPORTALPLANES)
 415                                 ranoutofportalplanes = true;
 416                         else
 417                         {
 418                                 // find the center by averaging
 419                                 VectorClear(center);
 420                                 for (i = 0;i < newpoints;i++)
 421                                         VectorAdd(center, portaltemppoints2[i], center);
 422                                 // ixtable is a 1.0f / N table
 423                                 VectorScale(center, ixtable[newpoints], center);
 424                                 // calculate the planes, and make sure the polygon can see it's own center
 425                                 newplanes = &portalplanes[firstclipplane + numclipplanes];
 426                                 for (prev = newpoints - 1, i = 0;i < newpoints;prev = i, i++)
 427                                 {
 428                                         VectorSubtract(info->eye, portaltemppoints2[i], v1);
 429                                         VectorSubtract(portaltemppoints2[prev], portaltemppoints2[i], v2);
 430                                         CrossProduct(v1, v2, newplanes[i].normal);
 431                                         VectorNormalizeFast(newplanes[i].normal);
 432                                         newplanes[i].dist = DotProduct(info->eye, newplanes[i].normal);
 433                                         if (DotProduct(newplanes[i].normal, center) <= newplanes[i].dist)
 434                                         {
 435                                                 // polygon can't see it's own center, discard and use parent portal
 436                                                 break;
 437                                         }
 438                                 }
 439                                 if (i == newpoints)
 440                                         Portal_RecursiveFlow(info, p->past, firstclipplane + numclipplanes, newpoints);
 441                                 else
 442                                         Portal_RecursiveFlow(info, p->past, firstclipplane, numclipplanes);
 443                         }
 444                 }
 445         }
 446 }
 447
 448 void Portal_RecursiveFindLeafForFlow(portalrecursioninfo_t *info, mnode_t *node)
 449 {
 450         if (node->contents)
 451         {
 452                 if (node->contents != CONTENTS_SKY && node->contents != CONTENTS_SOLID)
 453                         Portal_RecursiveFlow(info, (mleaf_t *)node, 0, info->numfrustumplanes);
 454         }
 455         else
 456         {
 457                 float f = DotProduct(info->eye, node->plane->normal) - node->plane->dist;
 458                 if (f > -0.1)
 459                         Portal_RecursiveFindLeafForFlow(info, node->children[0]);
 460                 if (f < 0.1)
 461                         Portal_RecursiveFindLeafForFlow(info, node->children[1]);
 462         }
 463 }
 464
 465 void Portal_Visibility(model_t *model, const vec3_t eye, qbyte *leafmark, qbyte *surfacemark, const mplane_t *frustumplanes, int numfrustumplanes, int exact, float radius)
 466 {
 467         int i;
 468         portalrecursioninfo_t info;
 469
 470         // if there is no model, it can not block visibility
 471         if (model == NULL)
 472                 Host_Error("Portal_Visibility: NULL model\n");
 473
 474         Mod_CheckLoaded(model);
 475
 476         if (model->type != mod_brush)
 477                 Host_Error("Portal_Visibility: not a brush model\n");
 478
 479         // put frustum planes (if any) into tinyplane format at start of buffer
 480         for (i = 0;i < numfrustumplanes;i++)
 481         {
 482                 VectorCopy(frustumplanes[i].normal, portalplanes[i].normal);
 483                 portalplanes[i].dist = frustumplanes[i].dist;
 484         }
 485
 486         ranoutofportalplanes = false;
 487         ranoutofportals = false;
 488
 489         info.nradius = -radius;
 490         info.exact = exact;
 491         info.surfacemark = surfacemark;
 492         info.leafmark = leafmark;
 493         info.model = model;
 494         VectorCopy(eye, info.eye);
 495         info.numfrustumplanes = numfrustumplanes;
 496
 497         Portal_RecursiveFindLeafForFlow(&info, model->nodes);
 498
 499         if (ranoutofportalplanes)
 500                 Con_Printf("Portal_RecursiveFlow: ran out of %d plane stack when recursing through portals\n", MAXRECURSIVEPORTALPLANES);
 501         if (ranoutofportals)
 502                 Con_Printf("Portal_RecursiveFlow: ran out of %d portal stack when recursing through portals\n", MAXRECURSIVEPORTALS);
 503 }
 504