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