portals.c

   1
   2 #include "quakedef.h"
   3 #include "polygon.h"
   4
   5 #define MAXRECURSIVEPORTALPLANES 1024
   6 #define MAXRECURSIVEPORTALS 256
   7
   8 static tinyplane_t portalplanes[MAXRECURSIVEPORTALPLANES];
   9 static int ranoutofportalplanes;
  10 static int ranoutofportals;
  11 static float portaltemppoints[2][256][3];
  12 static float portaltemppoints2[256][3];
  13 static int portal_markid = 0;
  14 static float boxpoints[4*3];
  15
  16 static int Portal_PortalThroughPortalPlanes(tinyplane_t *clipplanes, int clipnumplanes, float *targpoints, int targnumpoints, float *out, int maxpoints)
  17 {
  18         int numpoints, i;
  19         if (targnumpoints < 3)
  20                 return targnumpoints;
  21         if (maxpoints < 3)
  22                 return -1;
  23         numpoints = targnumpoints;
  24         memcpy(&portaltemppoints[0][0][0], targpoints, numpoints * 3 * sizeof(float));
  25         for (i = 0;i < clipnumplanes;i++)
  26         {
  27                 PolygonF_Divide(numpoints, &portaltemppoints[0][0][0], clipplanes[i].normal[0], clipplanes[i].normal[1], clipplanes[i].normal[2], clipplanes[i].dist, 1.0f/32.0f, 256, &portaltemppoints[1][0][0], &numpoints, 0, NULL, NULL);
  28                 if (numpoints < 3)
  29                         return numpoints;
  30                 memcpy(&portaltemppoints[0][0][0], &portaltemppoints[1][0][0], numpoints * 3 * sizeof(float));
  31         }
  32         if (numpoints > maxpoints)
  33                 return -1;
  34         memcpy(out, &portaltemppoints[0][0][0], numpoints * 3 * sizeof(float));
  35         return numpoints;
  36 }
  37
  38 static int Portal_RecursiveFlowSearch (mleaf_t *leaf, vec3_t eye, int firstclipplane, int numclipplanes)
  39 {
  40         mportal_t *p;
  41         int newpoints, i, prev;
  42         vec3_t center, v1, v2;
  43         tinyplane_t *newplanes;
  44
  45         if (leaf->portalmarkid == portal_markid)
  46                 return true;
  47
  48         // follow portals into other leafs
  49         for (p = leaf->portals;p;p = p->next)
  50         {
  51                 // only flow through portals facing away from the viewer
  52                 if (PlaneDiff(eye, (&p->plane)) < 0)
  53                 {
  54                         newpoints = Portal_PortalThroughPortalPlanes(&portalplanes[firstclipplane], numclipplanes, (float *) p->points, p->numpoints, &portaltemppoints2[0][0], 256);
  55                         if (newpoints < 3)
  56                                 continue;
  57                         else if (firstclipplane + numclipplanes + newpoints > MAXRECURSIVEPORTALPLANES)
  58                                 ranoutofportalplanes = true;
  59                         else
  60                         {
  61                                 // find the center by averaging
  62                                 VectorClear(center);
  63                                 for (i = 0;i < newpoints;i++)
  64                                         VectorAdd(center, portaltemppoints2[i], center);
  65                                 // ixtable is a 1.0f / N table
  66                                 VectorScale(center, ixtable[newpoints], center);
  67                                 // calculate the planes, and make sure the polygon can see it's own center
  68                                 newplanes = &portalplanes[firstclipplane + numclipplanes];
  69                                 for (prev = newpoints - 1, i = 0;i < newpoints;prev = i, i++)
  70                                 {
  71                                         VectorSubtract(eye, portaltemppoints2[i], v1);
  72                                         VectorSubtract(portaltemppoints2[prev], portaltemppoints2[i], v2);
  73                                         CrossProduct(v1, v2, newplanes[i].normal);
  74                                         VectorNormalize(newplanes[i].normal);
  75                                         newplanes[i].dist = DotProduct(eye, newplanes[i].normal);
  76                                         if (DotProduct(newplanes[i].normal, center) <= newplanes[i].dist)
  77                                         {
  78                                                 // polygon can't see it's own center, discard and use parent portal
  79                                                 break;
  80                                         }
  81                                 }
  82                                 if (i == newpoints)
  83                                 {
  84                                         if (Portal_RecursiveFlowSearch(p->past, eye, firstclipplane + numclipplanes, newpoints))
  85                                                 return true;
  86                                 }
  87                                 else
  88                                 {
  89                                         if (Portal_RecursiveFlowSearch(p->past, eye, firstclipplane, numclipplanes))
  90                                                 return true;
  91                                 }
  92                         }
  93                 }
  94         }
  95
  96         return false;
  97 }
  98
  99 static void Portal_PolygonRecursiveMarkLeafs(mnode_t *node, float *polypoints, int numpoints)
 100 {
 101         int i, front;
 102         float *p;
 103
 104 loc0:
 105         if (!node->plane)
 106         {
 107                 ((mleaf_t *)node)->portalmarkid = portal_markid;
 108                 return;
 109         }
 110
 111         front = 0;
 112         for (i = 0, p = polypoints;i < numpoints;i++, p += 3)
 113         {
 114                 if (DotProduct(p, node->plane->normal) > node->plane->dist)
 115                         front++;
 116         }
 117         if (front > 0)
 118         {
 119                 if (front == numpoints)
 120                 {
 121                         node = node->children[0];
 122                         goto loc0;
 123                 }
 124                 else
 125                         Portal_PolygonRecursiveMarkLeafs(node->children[0], polypoints, numpoints);
 126         }
 127         node = node->children[1];
 128         goto loc0;
 129 }
 130
 131 int Portal_CheckPolygon(model_t *model, vec3_t eye, float *polypoints, int numpoints)
 132 {
 133         int i, prev, returnvalue;
 134         mleaf_t *eyeleaf;
 135         vec3_t center, v1, v2;
 136
 137         // if there is no model, it can not block visibility
 138         if (model == NULL || !model->brush.PointInLeaf)
 139                 return true;
 140
 141         portal_markid++;
 142
 143         Mod_CheckLoaded(model);
 144         Portal_PolygonRecursiveMarkLeafs(model->brush.data_nodes, polypoints, numpoints);
 145
 146         eyeleaf = model->brush.PointInLeaf(model, eye);
 147
 148         // find the center by averaging
 149         VectorClear(center);
 150         for (i = 0;i < numpoints;i++)
 151                 VectorAdd(center, (&polypoints[i * 3]), center);
 152         // ixtable is a 1.0f / N table
 153         VectorScale(center, ixtable[numpoints], center);
 154
 155         // calculate the planes, and make sure the polygon can see it's own center
 156         for (prev = numpoints - 1, i = 0;i < numpoints;prev = i, i++)
 157         {
 158                 VectorSubtract(eye, (&polypoints[i * 3]), v1);
 159                 VectorSubtract((&polypoints[prev * 3]), (&polypoints[i * 3]), v2);
 160                 CrossProduct(v1, v2, portalplanes[i].normal);
 161                 VectorNormalize(portalplanes[i].normal);
 162                 portalplanes[i].dist = DotProduct(eye, portalplanes[i].normal);
 163                 if (DotProduct(portalplanes[i].normal, center) <= portalplanes[i].dist)
 164                 {
 165                         // polygon can't see it's own center, discard
 166                         return false;
 167                 }
 168         }
 169
 170         ranoutofportalplanes = false;
 171         ranoutofportals = false;
 172
 173         returnvalue = Portal_RecursiveFlowSearch(eyeleaf, eye, 0, numpoints);
 174
 175         if (ranoutofportalplanes)
 176                 Con_Printf("Portal_RecursiveFlowSearch: ran out of %d plane stack when recursing through portals\n", MAXRECURSIVEPORTALPLANES);
 177         if (ranoutofportals)
 178                 Con_Printf("Portal_RecursiveFlowSearch: ran out of %d portal stack when recursing through portals\n", MAXRECURSIVEPORTALS);
 179
 180         return returnvalue;
 181 }
 182
 183 #define Portal_MinsBoxPolygon(axis, axisvalue, x1, y1, z1, x2, y2, z2, x3, y3, z3, x4, y4, z4) \
 184 {\
 185         if (eye[(axis)] < ((axisvalue) - 0.5f))\
 186         {\
 187                 boxpoints[ 0] = x1;boxpoints[ 1] = y1;boxpoints[ 2] = z1;\
 188                 boxpoints[ 3] = x2;boxpoints[ 4] = y2;boxpoints[ 5] = z2;\
 189                 boxpoints[ 6] = x3;boxpoints[ 7] = y3;boxpoints[ 8] = z3;\
 190                 boxpoints[ 9] = x4;boxpoints[10] = y4;boxpoints[11] = z4;\
 191                 if (Portal_CheckPolygon(model, eye, boxpoints, 4))\
 192                         return true;\
 193         }\
 194 }
 195
 196 #define Portal_MaxsBoxPolygon(axis, axisvalue, x1, y1, z1, x2, y2, z2, x3, y3, z3, x4, y4, z4) \
 197 {\
 198         if (eye[(axis)] > ((axisvalue) + 0.5f))\
 199         {\
 200                 boxpoints[ 0] = x1;boxpoints[ 1] = y1;boxpoints[ 2] = z1;\
 201                 boxpoints[ 3] = x2;boxpoints[ 4] = y2;boxpoints[ 5] = z2;\
 202                 boxpoints[ 6] = x3;boxpoints[ 7] = y3;boxpoints[ 8] = z3;\
 203                 boxpoints[ 9] = x4;boxpoints[10] = y4;boxpoints[11] = z4;\
 204                 if (Portal_CheckPolygon(model, eye, boxpoints, 4))\
 205                         return true;\
 206         }\
 207 }
 208
 209 int Portal_CheckBox(model_t *model, vec3_t eye, vec3_t a, vec3_t b)
 210 {
 211         if (eye[0] >= (a[0] - 1.0f) && eye[0] < (b[0] + 1.0f)
 212          && eye[1] >= (a[1] - 1.0f) && eye[1] < (b[1] + 1.0f)
 213          && eye[2] >= (a[2] - 1.0f) && eye[2] < (b[2] + 1.0f))
 214                 return true;
 215
 216         Portal_MinsBoxPolygon
 217         (
 218                 0, a[0],
 219                 a[0], a[1], a[2],
 220                 a[0], b[1], a[2],
 221                 a[0], b[1], b[2],
 222                 a[0], a[1], b[2]
 223         );
 224         Portal_MaxsBoxPolygon
 225         (
 226                 0, b[0],
 227                 b[0], b[1], a[2],
 228                 b[0], a[1], a[2],
 229                 b[0], a[1], b[2],
 230                 b[0], b[1], b[2]
 231         );
 232         Portal_MinsBoxPolygon
 233         (
 234                 1, a[1],
 235                 b[0], a[1], a[2],
 236                 a[0], a[1], a[2],
 237                 a[0], a[1], b[2],
 238                 b[0], a[1], b[2]
 239         );
 240         Portal_MaxsBoxPolygon
 241         (
 242                 1, b[1],
 243                 a[0], b[1], a[2],
 244                 b[0], b[1], a[2],
 245                 b[0], b[1], b[2],
 246                 a[0], b[1], b[2]
 247         );
 248         Portal_MinsBoxPolygon
 249         (
 250                 2, a[2],
 251                 a[0], a[1], a[2],
 252                 b[0], a[1], a[2],
 253                 b[0], b[1], a[2],
 254                 a[0], b[1], a[2]
 255         );
 256         Portal_MaxsBoxPolygon
 257         (
 258                 2, b[2],
 259                 b[0], a[1], b[2],
 260                 a[0], a[1], b[2],
 261                 a[0], b[1], b[2],
 262                 b[0], b[1], b[2]
 263         );
 264
 265         return false;
 266 }
 267
 268 typedef struct portalrecursioninfo_s
 269 {
 270         int exact;
 271         int numfrustumplanes;
 272         vec3_t boxmins;
 273         vec3_t boxmaxs;
 274         int numsurfaces;
 275         int *surfacelist;
 276         qbyte *surfacepvs;
 277         int numleafs;
 278         int *leaflist;
 279         qbyte *leafpvs;
 280         model_t *model;
 281         vec3_t eye;
 282         float *updateleafsmins;
 283         float *updateleafsmaxs;
 284 }
 285 portalrecursioninfo_t;
 286
 287 static void Portal_RecursiveFlow (portalrecursioninfo_t *info, mleaf_t *leaf, int firstclipplane, int numclipplanes)
 288 {
 289         mportal_t *p;
 290         int newpoints, i, prev;
 291         float dist;
 292         vec3_t center;
 293         tinyplane_t *newplanes;
 294
 295         for (i = 0;i < 3;i++)
 296         {
 297                 if (info->updateleafsmins && info->updateleafsmins[i] > leaf->mins[i]) info->updateleafsmins[i] = leaf->mins[i];
 298                 if (info->updateleafsmaxs && info->updateleafsmaxs[i] < leaf->maxs[i]) info->updateleafsmaxs[i] = leaf->maxs[i];
 299         }
 300
 301
 302         if (info->leafpvs)
 303         {
 304                 int leafindex = leaf - info->model->brush.data_leafs;
 305                 if (!CHECKPVSBIT(info->leafpvs, leafindex))
 306                 {
 307                         SETPVSBIT(info->leafpvs, leafindex);
 308                         info->leaflist[info->numleafs++] = leafindex;
 309                 }
 310         }
 311
 312         // mark surfaces in leaf that can be seen through portal
 313         if (leaf->numleafsurfaces && info->surfacepvs)
 314         {
 315                 for (i = 0;i < leaf->numleafsurfaces;i++)
 316                 {
 317                         int surfaceindex = leaf->firstleafsurface[i];
 318                         if (!CHECKPVSBIT(info->surfacepvs, surfaceindex))
 319                         {
 320                                 msurface_t *surface = info->model->data_surfaces + surfaceindex;
 321                                 if (BoxesOverlap(surface->mins, surface->maxs, info->boxmins, info->boxmaxs))
 322                                 {
 323                                         if (info->exact)
 324                                         {
 325                                                 int j;
 326                                                 const int *elements;
 327                                                 const float *vertex3f;
 328                                                 float v[9], trimins[3], trimaxs[3];
 329                                                 vertex3f = surface->groupmesh->data_vertex3f;
 330                                                 elements = (surface->groupmesh->data_element3i + 3 * surface->num_firsttriangle);
 331                                                 for (j = 0;j < surface->num_triangles;j++, elements += 3)
 332                                                 {
 333                                                         VectorCopy(vertex3f + elements[0] * 3, v + 0);
 334                                                         VectorCopy(vertex3f + elements[1] * 3, v + 3);
 335                                                         VectorCopy(vertex3f + elements[2] * 3, v + 6);
 336                                                         if (PointInfrontOfTriangle(info->eye, v + 0, v + 3, v + 6))
 337                                                         {
 338                                                                 trimins[0] = min(v[0], min(v[3], v[6]));
 339                                                                 trimaxs[0] = max(v[0], max(v[3], v[6]));
 340                                                                 trimins[1] = min(v[1], min(v[4], v[7]));
 341                                                                 trimaxs[1] = max(v[1], max(v[4], v[7]));
 342                                                                 trimins[2] = min(v[2], min(v[5], v[8]));
 343                                                                 trimaxs[2] = max(v[2], max(v[5], v[8]));
 344                                                                 if (BoxesOverlap(trimins, trimaxs, info->boxmins, info->boxmaxs) && Portal_PortalThroughPortalPlanes(&portalplanes[firstclipplane], numclipplanes, v, 3, &portaltemppoints2[0][0], 256) >= 3)
 345                                                                 {
 346                                                                         SETPVSBIT(info->surfacepvs, surfaceindex);
 347                                                                         info->surfacelist[info->numsurfaces++] = surfaceindex;
 348                                                                         break;
 349                                                                 }
 350                                                         }
 351                                                 }
 352                                         }
 353                                         else
 354                                         {
 355                                                 SETPVSBIT(info->surfacepvs, surfaceindex);
 356                                                 info->surfacelist[info->numsurfaces++] = surfaceindex;
 357                                         }
 358                                 }
 359                         }
 360                 }
 361         }
 362
 363         // follow portals into other leafs
 364         for (p = leaf->portals;p;p = p->next)
 365         {
 366                 // only flow through portals facing the viewer
 367                 dist = PlaneDiff(info->eye, (&p->plane));
 368                 if (dist < 0 && BoxesOverlap(p->past->mins, p->past->maxs, info->boxmins, info->boxmaxs))
 369                 {
 370                         newpoints = Portal_PortalThroughPortalPlanes(&portalplanes[firstclipplane], numclipplanes, (float *) p->points, p->numpoints, &portaltemppoints2[0][0], 256);
 371                         if (newpoints < 3)
 372                                 continue;
 373                         else if (firstclipplane + numclipplanes + newpoints > MAXRECURSIVEPORTALPLANES)
 374                                 ranoutofportalplanes = true;
 375                         else
 376                         {
 377                                 // find the center by averaging
 378                                 VectorClear(center);
 379                                 for (i = 0;i < newpoints;i++)
 380                                         VectorAdd(center, portaltemppoints2[i], center);
 381                                 // ixtable is a 1.0f / N table
 382                                 VectorScale(center, ixtable[newpoints], center);
 383                                 // calculate the planes, and make sure the polygon can see its own center
 384                                 newplanes = &portalplanes[firstclipplane + numclipplanes];
 385                                 for (prev = newpoints - 1, i = 0;i < newpoints;prev = i, i++)
 386                                 {
 387                                         TriangleNormal(portaltemppoints2[prev], portaltemppoints2[i], info->eye, newplanes[i].normal);
 388                                         VectorNormalize(newplanes[i].normal);
 389                                         newplanes[i].dist = DotProduct(info->eye, newplanes[i].normal);
 390                                         if (DotProduct(newplanes[i].normal, center) <= newplanes[i].dist)
 391                                         {
 392                                                 // polygon can't see its own center, discard and use parent portal
 393                                                 break;
 394                                         }
 395                                 }
 396                                 if (i == newpoints)
 397                                         Portal_RecursiveFlow(info, p->past, firstclipplane + numclipplanes, newpoints);
 398                                 else
 399                                         Portal_RecursiveFlow(info, p->past, firstclipplane, numclipplanes);
 400                         }
 401                 }
 402         }
 403 }
 404
 405 static void Portal_RecursiveFindLeafForFlow(portalrecursioninfo_t *info, mnode_t *node)
 406 {
 407         if (node->plane)
 408         {
 409                 float f = DotProduct(info->eye, node->plane->normal) - node->plane->dist;
 410                 if (f > -0.1)
 411                         Portal_RecursiveFindLeafForFlow(info, node->children[0]);
 412                 if (f < 0.1)
 413                         Portal_RecursiveFindLeafForFlow(info, node->children[1]);
 414         }
 415         else
 416         {
 417                 mleaf_t *leaf = (mleaf_t *)node;
 418                 if (leaf->clusterindex >= 0)
 419                         Portal_RecursiveFlow(info, leaf, 0, info->numfrustumplanes);
 420         }
 421 }
 422
 423 void Portal_Visibility(model_t *model, const vec3_t eye, int *leaflist, qbyte *leafpvs, int *numleafspointer, int *surfacelist, qbyte *surfacepvs, int *numsurfacespointer, const mplane_t *frustumplanes, int numfrustumplanes, int exact, const float *boxmins, const float *boxmaxs, float *updateleafsmins, float *updateleafsmaxs)
 424 {
 425         int i;
 426         portalrecursioninfo_t info;
 427
 428         // if there is no model, it can not block visibility
 429         if (model == NULL)
 430         {
 431                 Con_Print("Portal_Visibility: NULL model\n");
 432                 return;
 433         }
 434
 435         Mod_CheckLoaded(model);
 436
 437         if (!model->brush.data_nodes)
 438         {
 439                 Con_Print("Portal_Visibility: not a brush model\n");
 440                 return;
 441         }
 442
 443         // put frustum planes (if any) into tinyplane format at start of buffer
 444         for (i = 0;i < numfrustumplanes;i++)
 445         {
 446                 VectorCopy(frustumplanes[i].normal, portalplanes[i].normal);
 447                 portalplanes[i].dist = frustumplanes[i].dist;
 448         }
 449
 450         ranoutofportalplanes = false;
 451         ranoutofportals = false;
 452
 453         VectorCopy(boxmins, info.boxmins);
 454         VectorCopy(boxmaxs, info.boxmaxs);
 455         info.exact = exact;
 456         info.numsurfaces = 0;
 457         info.surfacelist = surfacelist;
 458         info.surfacepvs = surfacepvs;
 459         info.numleafs = 0;
 460         info.leaflist = leaflist;
 461         info.leafpvs = leafpvs;
 462         info.model = model;
 463         VectorCopy(eye, info.eye);
 464         info.numfrustumplanes = numfrustumplanes;
 465         info.updateleafsmins = updateleafsmins;
 466         info.updateleafsmaxs = updateleafsmaxs;
 467
 468         Portal_RecursiveFindLeafForFlow(&info, model->brush.data_nodes);
 469
 470         if (ranoutofportalplanes)
 471                 Con_Printf("Portal_RecursiveFlow: ran out of %d plane stack when recursing through portals\n", MAXRECURSIVEPORTALPLANES);
 472         if (ranoutofportals)
 473                 Con_Printf("Portal_RecursiveFlow: ran out of %d portal stack when recursing through portals\n", MAXRECURSIVEPORTALS);
 474         if (numsurfacespointer)
 475                 *numsurfacespointer = info.numsurfaces;
 476         if (numleafspointer)
 477                 *numleafspointer = info.numleafs;
 478 }
 479