tools/quake3/q3map2/facebsp.c

   1 /* -------------------------------------------------------------------------------
   2
   3 Copyright (C) 1999-2006 Id Software, Inc. and contributors.
   4 For a list of contributors, see the accompanying CONTRIBUTORS file.
   5
   6 This file is part of GtkRadiant.
   7
   8 GtkRadiant is free software; you can redistribute it and/or modify
   9 it under the terms of the GNU General Public License as published by
  10 the Free Software Foundation; either version 2 of the License, or
  11 (at your option) any later version.
  12
  13 GtkRadiant is distributed in the hope that it will be useful,
  14 but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 GNU General Public License for more details.
  17
  18 You should have received a copy of the GNU General Public License
  19 along with GtkRadiant; if not, write to the Free Software
  20 Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  21
  22 ----------------------------------------------------------------------------------
  23
  24 This code has been altered significantly from its original form, to support
  25 several games based on the Quake III Arena engine, in the form of "Q3Map2."
  26
  27 ------------------------------------------------------------------------------- */
  28
  29
  30
  31 /* marker */
  32 #define FACEBSP_C
  33
  34
  35
  36 /* dependencies */
  37 #include "q3map2.h"
  38
  39
  40
  41 int                     c_faceLeafs;
  42
  43
  44 /*
  45 ================
  46 AllocBspFace
  47 ================
  48 */
  49 face_t  *AllocBspFace( void ) {
  50         face_t  *f;
  51
  52         f = safe_malloc(sizeof(*f));
  53         memset( f, 0, sizeof(*f) );
  54
  55         return f;
  56 }
  57
  58
  59
  60 /*
  61 ================
  62 FreeBspFace
  63 ================
  64 */
  65 void    FreeBspFace( face_t *f ) {
  66         if ( f->w ) {
  67                 FreeWinding( f->w );
  68         }
  69         free( f );
  70 }
  71
  72
  73
  74 /*
  75 SelectSplitPlaneNum()
  76 finds the best split plane for this node
  77 */
  78
  79 static void SelectSplitPlaneNum( node_t *node, face_t *list, int *splitPlaneNum, int *compileFlags )
  80 {
  81         face_t          *split;
  82         face_t          *check;
  83         face_t          *bestSplit;
  84         int                     splits, facing, front, back;
  85         int                     side;
  86         plane_t         *plane;
  87         int                     value, bestValue;
  88         int                     i;
  89         vec3_t          normal;
  90         float           dist;
  91         int                     planenum;
  92
  93
  94         /* ydnar: set some defaults */
  95         *splitPlaneNum = -1; /* leaf */
  96         *compileFlags = 0;
  97
  98         /* ydnar 2002-06-24: changed this to split on z-axis as well */
  99         /* ydnar 2002-09-21: changed blocksize to be a vector, so mappers can specify a 3 element value */
 100
 101         /* if it is crossing a block boundary, force a split */
 102         for( i = 0; i < 3; i++ )
 103         {
 104                 if( blockSize[ i ] <= 0 )
 105                         continue;
 106                 dist = blockSize[ i ] * (floor( node->mins[ i ] / blockSize[ i ] ) + 1);
 107                 if( node->maxs[ i ] > dist )
 108                 {
 109                         VectorClear( normal );
 110                         normal[ i ] = 1;
 111                         planenum = FindFloatPlane( normal, dist, 0, NULL );
 112                         *splitPlaneNum = planenum;
 113                         return;
 114                 }
 115         }
 116
 117         /* pick one of the face planes */
 118         bestValue = -99999;
 119         bestSplit = list;
 120
 121         for( split = list; split; split = split->next )
 122                 split->checked = qfalse;
 123
 124         for( split = list; split; split = split->next )
 125         {
 126                 if ( split->checked )
 127                         continue;
 128
 129                 plane = &mapplanes[ split->planenum ];
 130                 splits = 0;
 131                 facing = 0;
 132                 front = 0;
 133                 back = 0;
 134                 for ( check = list ; check ; check = check->next ) {
 135                         if ( check->planenum == split->planenum ) {
 136                                 facing++;
 137                                 check->checked = qtrue; // won't need to test this plane again
 138                                 continue;
 139                         }
 140                         side = WindingOnPlaneSide( check->w, plane->normal, plane->dist );
 141                         if ( side == SIDE_CROSS ) {
 142                                 splits++;
 143                         } else if ( side == SIDE_FRONT ) {
 144                                 front++;
 145                         } else if ( side == SIDE_BACK ) {
 146                                 back++;
 147                         }
 148                 }
 149                 value =  5*facing - 5*splits; // - abs(front-back);
 150                 if ( plane->type < 3 ) {
 151                         value+=5;               // axial is better
 152                 }
 153                 value += split->priority;               // prioritize hints higher
 154
 155                 if ( value > bestValue ) {
 156                         bestValue = value;
 157                         bestSplit = split;
 158                 }
 159         }
 160
 161         /* nothing, we have a leaf */
 162         if( bestValue == -99999 )
 163                 return;
 164
 165         /* set best split data */
 166         *splitPlaneNum = bestSplit->planenum;
 167         *compileFlags = bestSplit->compileFlags;
 168 }
 169
 170
 171
 172 /*
 173 CountFaceList()
 174 counts bsp faces in the linked list
 175 */
 176
 177 int     CountFaceList( face_t *list )
 178 {
 179         int             c;
 180
 181
 182         c = 0;
 183         for( list; list != NULL; list = list->next )
 184                 c++;
 185         return c;
 186 }
 187
 188
 189
 190 /*
 191 BuildFaceTree_r()
 192 recursively builds the bsp, splitting on face planes
 193 */
 194
 195 void BuildFaceTree_r( node_t *node, face_t *list )
 196 {
 197         face_t          *split;
 198         face_t          *next;
 199         int                     side;
 200         plane_t         *plane;
 201         face_t          *newFace;
 202         face_t          *childLists[2];
 203         winding_t       *frontWinding, *backWinding;
 204         int                     i;
 205         int                     splitPlaneNum, compileFlags;
 206
 207
 208         /* count faces left */
 209         i = CountFaceList( list );
 210
 211         /* select the best split plane */
 212         SelectSplitPlaneNum( node, list, &splitPlaneNum, &compileFlags );
 213
 214         /* if we don't have any more faces, this is a node */
 215         if ( splitPlaneNum == -1 )
 216         {
 217                 node->planenum = PLANENUM_LEAF;
 218                 c_faceLeafs++;
 219                 return;
 220         }
 221
 222         /* partition the list */
 223         node->planenum = splitPlaneNum;
 224         node->compileFlags = compileFlags;
 225         plane = &mapplanes[ splitPlaneNum ];
 226         childLists[0] = NULL;
 227         childLists[1] = NULL;
 228         for( split = list; split; split = next )
 229         {
 230                 /* set next */
 231                 next = split->next;
 232
 233                 /* don't split by identical plane */
 234                 if( split->planenum == node->planenum )
 235                 {
 236                         FreeBspFace( split );
 237                         continue;
 238                 }
 239
 240                 /* determine which side the face falls on */
 241                 side = WindingOnPlaneSide( split->w, plane->normal, plane->dist );
 242
 243                 /* switch on side */
 244                 if( side == SIDE_CROSS )
 245                 {
 246                         ClipWindingEpsilon( split->w, plane->normal, plane->dist, CLIP_EPSILON * 2,
 247                                 &frontWinding, &backWinding );
 248                         if( frontWinding ) {
 249                                 newFace = AllocBspFace();
 250                                 newFace->w = frontWinding;
 251                                 newFace->next = childLists[0];
 252                                 newFace->planenum = split->planenum;
 253                                 newFace->priority = split->priority;
 254                                 newFace->compileFlags = split->compileFlags;
 255                                 childLists[0] = newFace;
 256                         }
 257                         if( backWinding ) {
 258                                 newFace = AllocBspFace();
 259                                 newFace->w = backWinding;
 260                                 newFace->next = childLists[1];
 261                                 newFace->planenum = split->planenum;
 262                                 newFace->priority = split->priority;
 263                                 newFace->compileFlags = split->compileFlags;
 264                                 childLists[1] = newFace;
 265                         }
 266                         FreeBspFace( split );
 267                 } else if ( side == SIDE_FRONT ) {
 268                         split->next = childLists[0];
 269                         childLists[0] = split;
 270                 } else if ( side == SIDE_BACK ) {
 271                         split->next = childLists[1];
 272                         childLists[1] = split;
 273                 }
 274         }
 275
 276
 277         // recursively process children
 278         for ( i = 0 ; i < 2 ; i++ ) {
 279                 node->children[i] = AllocNode();
 280                 node->children[i]->parent = node;
 281                 VectorCopy( node->mins, node->children[i]->mins );
 282                 VectorCopy( node->maxs, node->children[i]->maxs );
 283         }
 284
 285         for ( i = 0 ; i < 3 ; i++ ) {
 286                 if ( plane->normal[i] == 1 ) {
 287                         node->children[0]->mins[i] = plane->dist;
 288                         node->children[1]->maxs[i] = plane->dist;
 289                         break;
 290                 }
 291         }
 292
 293         for ( i = 0 ; i < 2 ; i++ ) {
 294                 BuildFaceTree_r ( node->children[i], childLists[i]);
 295         }
 296 }
 297
 298
 299 /*
 300 ================
 301 FaceBSP
 302
 303 List will be freed before returning
 304 ================
 305 */
 306 tree_t *FaceBSP( face_t *list ) {
 307         tree_t          *tree;
 308         face_t  *face;
 309         int                     i;
 310         int                     count;
 311
 312         Sys_FPrintf (SYS_VRB, "--- FaceBSP ---\n" );
 313
 314         tree = AllocTree ();
 315
 316         count = 0;
 317         for( face = list; face != NULL; face = face->next )
 318         {
 319                 count++;
 320                 for( i = 0; i < face->w->numpoints; i++ )
 321                 {
 322                         AddPointToBounds( face->w->p[ i ], tree->mins, tree->maxs );
 323                 }
 324         }
 325         Sys_FPrintf( SYS_VRB, "%9d faces\n", count );
 326
 327         tree->headnode = AllocNode();
 328         VectorCopy( tree->mins, tree->headnode->mins );
 329         VectorCopy( tree->maxs, tree->headnode->maxs );
 330         c_faceLeafs = 0;
 331
 332         BuildFaceTree_r ( tree->headnode, list );
 333
 334         Sys_FPrintf( SYS_VRB, "%9d leafs\n", c_faceLeafs );
 335
 336         return tree;
 337 }
 338
 339
 340
 341 /*
 342 MakeStructuralBSPFaceList()
 343 get structural brush faces
 344 */
 345
 346 face_t *MakeStructuralBSPFaceList( brush_t *list )
 347 {
 348         brush_t         *b;
 349         int                     i;
 350         side_t          *s;
 351         winding_t       *w;
 352         face_t          *f, *flist;
 353
 354
 355         flist = NULL;
 356         for( b = list; b != NULL; b = b->next )
 357         {
 358                 if( b->detail )
 359                         continue;
 360
 361                 for( i = 0; i < b->numsides; i++ )
 362                 {
 363                         /* get side and winding */
 364                         s = &b->sides[ i ];
 365                         w = s->winding;
 366                         if( w == NULL )
 367                                 continue;
 368
 369                         /* ydnar: skip certain faces */
 370                         if( s->compileFlags & C_SKIP )
 371                                 continue;
 372
 373                         /* allocate a face */
 374                         f = AllocBspFace();
 375                         f->w = CopyWinding( w );
 376                         f->planenum = s->planenum & ~1;
 377                         f->compileFlags = s->compileFlags;      /* ydnar */
 378
 379                         /* ydnar: set priority */
 380                         f->priority = 0;
 381                         if( f->compileFlags & C_HINT )
 382                                 f->priority += HINT_PRIORITY;
 383                         if( f->compileFlags & C_ANTIPORTAL )
 384                                 f->priority += ANTIPORTAL_PRIORITY;
 385                         if( f->compileFlags & C_AREAPORTAL )
 386                                 f->priority += AREAPORTAL_PRIORITY;
 387
 388                         /* get next face */
 389                         f->next = flist;
 390                         flist = f;
 391                 }
 392         }
 393
 394         return flist;
 395 }
 396
 397
 398
 399 /*
 400 MakeVisibleBSPFaceList()
 401 get visible brush faces
 402 */
 403
 404 face_t *MakeVisibleBSPFaceList( brush_t *list )
 405 {
 406         brush_t         *b;
 407         int                     i;
 408         side_t          *s;
 409         winding_t       *w;
 410         face_t          *f, *flist;
 411
 412
 413         flist = NULL;
 414         for( b = list; b != NULL; b = b->next )
 415         {
 416                 if( b->detail )
 417                         continue;
 418
 419                 for( i = 0; i < b->numsides; i++ )
 420                 {
 421                         /* get side and winding */
 422                         s = &b->sides[ i ];
 423                         w = s->visibleHull;
 424                         if( w == NULL )
 425                                 continue;
 426
 427                         /* ydnar: skip certain faces */
 428                         if( s->compileFlags & C_SKIP )
 429                                 continue;
 430
 431                         /* allocate a face */
 432                         f = AllocBspFace();
 433                         f->w = CopyWinding( w );
 434                         f->planenum = s->planenum & ~1;
 435                         f->compileFlags = s->compileFlags;      /* ydnar */
 436
 437                         /* ydnar: set priority */
 438                         f->priority = 0;
 439                         if( f->compileFlags & C_HINT )
 440                                 f->priority += HINT_PRIORITY;
 441                         if( f->compileFlags & C_ANTIPORTAL )
 442                                 f->priority += ANTIPORTAL_PRIORITY;
 443                         if( f->compileFlags & C_AREAPORTAL )
 444                                 f->priority += AREAPORTAL_PRIORITY;
 445
 446                         /* get next face */
 447                         f->next = flist;
 448                         flist = f;
 449                 }
 450         }
 451
 452         return flist;
 453 }
 454