src/dungeongen.cpp

   1 /*
   2 Minetest
   3 Copyright (C) 2010-2013 celeron55, Perttu Ahola <celeron55@gmail.com>
   4
   5 This program is free software; you can redistribute it and/or modify
   6 it under the terms of the GNU Lesser General Public License as published by
   7 the Free Software Foundation; either version 2.1 of the License, or
   8 (at your option) any later version.
   9
  10 This program is distributed in the hope that it will be useful,
  11 but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 GNU Lesser General Public License for more details.
  14
  15 You should have received a copy of the GNU Lesser General Public License along
  16 with this program; if not, write to the Free Software Foundation, Inc.,
  17 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  18 */
  19
  20 #include "dungeongen.h"
  21 #include "mapgen.h"
  22 #include "voxel.h"
  23 #include "noise.h"
  24 #include "mapblock.h"
  25 #include "mapnode.h"
  26 #include "map.h"
  27 #include "nodedef.h"
  28 #include "profiler.h"
  29 #include "settings.h"
  30
  31 //#define DGEN_USE_TORCHES
  32
  33 NoiseParams nparams_dungeon_rarity(0.0, 1.0, v3f(500.0, 500.0, 500.0), 0, 2, 0.8, 2.0);
  34 NoiseParams nparams_dungeon_wetness(0.0, 1.0, v3f(40.0, 40.0, 40.0), 32474, 4, 1.1, 2.0);
  35 NoiseParams nparams_dungeon_density(0.0, 1.0, v3f(2.5, 2.5, 2.5), 0, 2, 1.4, 2.0);
  36
  37
  38 ///////////////////////////////////////////////////////////////////////////////
  39
  40
  41 DungeonGen::DungeonGen(Mapgen *mapgen, DungeonParams *dparams) {
  42         this->mg = mapgen;
  43         this->vm = mapgen->vm;
  44
  45 #ifdef DGEN_USE_TORCHES
  46         c_torch  = ndef->getId("default:torch");
  47 #endif
  48
  49         if (dparams) {
  50                 memcpy(&dp, dparams, sizeof(dp));
  51         } else {
  52                 dp.c_water  = mg->ndef->getId("mapgen_water_source");
  53                 dp.c_cobble = mg->ndef->getId("mapgen_cobble");
  54                 dp.c_moss   = mg->ndef->getId("mapgen_mossycobble");
  55                 dp.c_stair  = mg->ndef->getId("mapgen_stair_cobble");
  56
  57                 dp.diagonal_dirs = false;
  58                 dp.mossratio  = 3.0;
  59                 dp.holesize   = v3s16(1, 2, 1);
  60                 dp.roomsize   = v3s16(0,0,0);
  61                 dp.notifytype = GENNOTIFY_DUNGEON;
  62
  63                 dp.np_rarity  = nparams_dungeon_rarity;
  64                 dp.np_wetness = nparams_dungeon_wetness;
  65                 dp.np_density = nparams_dungeon_density;
  66         }
  67 }
  68
  69
  70 void DungeonGen::generate(u32 bseed, v3s16 nmin, v3s16 nmax) {
  71         //TimeTaker t("gen dungeons");
  72         if (NoisePerlin3D(&dp.np_rarity, nmin.X, nmin.Y, nmin.Z, mg->seed) < 0.2)
  73                 return;
  74
  75         this->blockseed = bseed;
  76         random.seed(bseed + 2);
  77
  78         // Dungeon generator doesn't modify places which have this set
  79         vm->clearFlag(VMANIP_FLAG_DUNGEON_INSIDE | VMANIP_FLAG_DUNGEON_PRESERVE);
  80
  81         bool no_float = !g_settings->getBool("enable_floating_dungeons");
  82
  83         // Set all air and water (and optionally ignore) to be untouchable
  84         // to make dungeons open to caves and open air
  85         for (s16 z = nmin.Z; z <= nmax.Z; z++) {
  86                 for (s16 y = nmin.Y; y <= nmax.Y; y++) {
  87                         u32 i = vm->m_area.index(nmin.X, y, z);
  88                         for (s16 x = nmin.X; x <= nmax.X; x++) {
  89                                 content_t c = vm->m_data[i].getContent();
  90                                 if (c == CONTENT_AIR || c == dp.c_water
  91                                                 || (no_float && c == CONTENT_IGNORE))
  92                                         vm->m_flags[i] |= VMANIP_FLAG_DUNGEON_PRESERVE;
  93                                 i++;
  94                         }
  95                 }
  96         }
  97
  98         // Add it
  99         makeDungeon(v3s16(1,1,1) * MAP_BLOCKSIZE);
 100
 101         // Convert some cobble to mossy cobble
 102         if (dp.mossratio != 0.0) {
 103                 for (s16 z = nmin.Z; z <= nmax.Z; z++)
 104                 for (s16 y = nmin.Y; y <= nmax.Y; y++) {
 105                         u32 i = vm->m_area.index(nmin.X, y, z);
 106                         for (s16 x = nmin.X; x <= nmax.X; x++) {
 107                                 if (vm->m_data[i].getContent() == dp.c_cobble) {
 108                                         float wetness = NoisePerlin3D(&dp.np_wetness, x, y, z, mg->seed);
 109                                         float density = NoisePerlin3D(&dp.np_density, x, y, z, blockseed);
 110                                         if (density < wetness / dp.mossratio)
 111                                                 vm->m_data[i].setContent(dp.c_moss);
 112                                 }
 113                                 i++;
 114                         }
 115                 }
 116         }
 117
 118         //printf("== gen dungeons: %dms\n", t.stop());
 119 }
 120
 121
 122 void DungeonGen::makeDungeon(v3s16 start_padding)
 123 {
 124         v3s16 areasize = vm->m_area.getExtent();
 125         v3s16 roomsize;
 126         v3s16 roomplace;
 127
 128         /*
 129                 Find place for first room
 130         */
 131         bool fits = false;
 132         for (u32 i = 0; i < 100 && !fits; i++)
 133         {
 134                 bool is_large_room = ((random.next() & 3) == 1);
 135                 roomsize = is_large_room ?
 136                         v3s16(random.range(8, 16),random.range(8, 16),random.range(8, 16)) :
 137                         v3s16(random.range(4,  8),random.range(4,  6),random.range(4, 8));
 138                 roomsize += dp.roomsize;
 139
 140                 // start_padding is used to disallow starting the generation of
 141                 // a dungeon in a neighboring generation chunk
 142                 roomplace = vm->m_area.MinEdge + start_padding + v3s16(
 143                         random.range(0,areasize.X-roomsize.X-1-start_padding.X),
 144                         random.range(0,areasize.Y-roomsize.Y-1-start_padding.Y),
 145                         random.range(0,areasize.Z-roomsize.Z-1-start_padding.Z));
 146
 147                 /*
 148                         Check that we're not putting the room to an unknown place,
 149                         otherwise it might end up floating in the air
 150                 */
 151                 fits = true;
 152                 for (s16 z = 1; z < roomsize.Z - 1; z++)
 153                 for (s16 y = 1; y < roomsize.Y - 1; y++)
 154                 for (s16 x = 1; x < roomsize.X - 1; x++)
 155                 {
 156                         v3s16 p = roomplace + v3s16(x, y, z);
 157                         u32 vi = vm->m_area.index(p);
 158                         if ((vm->m_flags[vi] & VMANIP_FLAG_DUNGEON_INSIDE) ||
 159                                 vm->m_data[vi].getContent() == CONTENT_IGNORE) {
 160                                 fits = false;
 161                                 break;
 162                         }
 163                 }
 164         }
 165         // No place found
 166         if (fits == false)
 167                 return;
 168
 169         /*
 170                 Stores the center position of the last room made, so that
 171                 a new corridor can be started from the last room instead of
 172                 the new room, if chosen so.
 173         */
 174         v3s16 last_room_center = roomplace + v3s16(roomsize.X / 2, 1, roomsize.Z / 2);
 175
 176         u32 room_count = random.range(2, 16);
 177         for (u32 i = 0; i < room_count; i++)
 178         {
 179                 // Make a room to the determined place
 180                 makeRoom(roomsize, roomplace);
 181
 182                 v3s16 room_center = roomplace + v3s16(roomsize.X / 2, 1, roomsize.Z / 2);
 183                 mg->gennotify.addEvent(dp.notifytype, room_center);
 184
 185 #ifdef DGEN_USE_TORCHES
 186                 // Place torch at room center (for testing)
 187                 vm->m_data[vm->m_area.index(room_center)] = MapNode(c_torch);
 188 #endif
 189
 190                 // Quit if last room
 191                 if (i == room_count - 1)
 192                         break;
 193
 194                 // Determine walker start position
 195
 196                 bool start_in_last_room = (random.range(0, 2) != 0);
 197
 198                 v3s16 walker_start_place;
 199
 200                 if (start_in_last_room) {
 201                         walker_start_place = last_room_center;
 202                 } else {
 203                         walker_start_place = room_center;
 204                         // Store center of current room as the last one
 205                         last_room_center = room_center;
 206                 }
 207
 208                 // Create walker and find a place for a door
 209                 v3s16 doorplace;
 210                 v3s16 doordir;
 211
 212                 m_pos = walker_start_place;
 213                 if (!findPlaceForDoor(doorplace, doordir))
 214                         return;
 215
 216                 if (random.range(0,1) == 0)
 217                         // Make the door
 218                         makeDoor(doorplace, doordir);
 219                 else
 220                         // Don't actually make a door
 221                         doorplace -= doordir;
 222
 223                 // Make a random corridor starting from the door
 224                 v3s16 corridor_end;
 225                 v3s16 corridor_end_dir;
 226                 makeCorridor(doorplace, doordir, corridor_end, corridor_end_dir);
 227
 228                 // Find a place for a random sized room
 229                 roomsize = v3s16(random.range(4,8),random.range(4,6),random.range(4,8));
 230                 roomsize += dp.roomsize;
 231
 232                 m_pos = corridor_end;
 233                 m_dir = corridor_end_dir;
 234                 if (!findPlaceForRoomDoor(roomsize, doorplace, doordir, roomplace))
 235                         return;
 236
 237                 if (random.range(0,1) == 0)
 238                         // Make the door
 239                         makeDoor(doorplace, doordir);
 240                 else
 241                         // Don't actually make a door
 242                         roomplace -= doordir;
 243
 244         }
 245 }
 246
 247
 248 void DungeonGen::makeRoom(v3s16 roomsize, v3s16 roomplace)
 249 {
 250         MapNode n_cobble(dp.c_cobble);
 251         MapNode n_air(CONTENT_AIR);
 252
 253         // Make +-X walls
 254         for (s16 z = 0; z < roomsize.Z; z++)
 255         for (s16 y = 0; y < roomsize.Y; y++)
 256         {
 257                 {
 258                         v3s16 p = roomplace + v3s16(0, y, z);
 259                         if (vm->m_area.contains(p) == false)
 260                                 continue;
 261                         u32 vi = vm->m_area.index(p);
 262                         if (vm->m_flags[vi] & VMANIP_FLAG_DUNGEON_UNTOUCHABLE)
 263                                 continue;
 264                         vm->m_data[vi] = n_cobble;
 265                 }
 266                 {
 267                         v3s16 p = roomplace + v3s16(roomsize.X - 1, y, z);
 268                         if (vm->m_area.contains(p) == false)
 269                                 continue;
 270                         u32 vi = vm->m_area.index(p);
 271                         if (vm->m_flags[vi] & VMANIP_FLAG_DUNGEON_UNTOUCHABLE)
 272                                 continue;
 273                         vm->m_data[vi] = n_cobble;
 274                 }
 275         }
 276
 277         // Make +-Z walls
 278         for (s16 x = 0; x < roomsize.X; x++)
 279         for (s16 y = 0; y < roomsize.Y; y++)
 280         {
 281                 {
 282                         v3s16 p = roomplace + v3s16(x, y, 0);
 283                         if (vm->m_area.contains(p) == false)
 284                                 continue;
 285                         u32 vi = vm->m_area.index(p);
 286                         if (vm->m_flags[vi] & VMANIP_FLAG_DUNGEON_UNTOUCHABLE)
 287                                 continue;
 288                         vm->m_data[vi] = n_cobble;
 289                 }
 290                 {
 291                         v3s16 p = roomplace + v3s16(x, y, roomsize.Z - 1);
 292                         if (vm->m_area.contains(p) == false)
 293                                 continue;
 294                         u32 vi = vm->m_area.index(p);
 295                         if (vm->m_flags[vi] & VMANIP_FLAG_DUNGEON_UNTOUCHABLE)
 296                                 continue;
 297                         vm->m_data[vi] = n_cobble;
 298                 }
 299         }
 300
 301         // Make +-Y walls (floor and ceiling)
 302         for (s16 z = 0; z < roomsize.Z; z++)
 303         for (s16 x = 0; x < roomsize.X; x++)
 304         {
 305                 {
 306                         v3s16 p = roomplace + v3s16(x, 0, z);
 307                         if (vm->m_area.contains(p) == false)
 308                                 continue;
 309                         u32 vi = vm->m_area.index(p);
 310                         if (vm->m_flags[vi] & VMANIP_FLAG_DUNGEON_UNTOUCHABLE)
 311                                 continue;
 312                         vm->m_data[vi] = n_cobble;
 313                 }
 314                 {
 315                         v3s16 p = roomplace + v3s16(x,roomsize. Y - 1, z);
 316                         if (vm->m_area.contains(p) == false)
 317                                 continue;
 318                         u32 vi = vm->m_area.index(p);
 319                         if (vm->m_flags[vi] & VMANIP_FLAG_DUNGEON_UNTOUCHABLE)
 320                                 continue;
 321                         vm->m_data[vi] = n_cobble;
 322                 }
 323         }
 324
 325         // Fill with air
 326         for (s16 z = 1; z < roomsize.Z - 1; z++)
 327         for (s16 y = 1; y < roomsize.Y - 1; y++)
 328         for (s16 x = 1; x < roomsize.X - 1; x++)
 329         {
 330                 v3s16 p = roomplace + v3s16(x, y, z);
 331                 if (vm->m_area.contains(p) == false)
 332                         continue;
 333                 u32 vi = vm->m_area.index(p);
 334                 vm->m_flags[vi] |= VMANIP_FLAG_DUNGEON_UNTOUCHABLE;
 335                 vm->m_data[vi]   = n_air;
 336         }
 337 }
 338
 339
 340 void DungeonGen::makeFill(v3s16 place, v3s16 size,
 341                 u8 avoid_flags, MapNode n, u8 or_flags)
 342 {
 343         for (s16 z = 0; z < size.Z; z++)
 344         for (s16 y = 0; y < size.Y; y++)
 345         for (s16 x = 0; x < size.X; x++)
 346         {
 347                 v3s16 p = place + v3s16(x, y, z);
 348                 if (vm->m_area.contains(p) == false)
 349                         continue;
 350                 u32 vi = vm->m_area.index(p);
 351                 if (vm->m_flags[vi] & avoid_flags)
 352                         continue;
 353                 vm->m_flags[vi] |= or_flags;
 354                 vm->m_data[vi]   = n;
 355         }
 356 }
 357
 358
 359 void DungeonGen::makeHole(v3s16 place)
 360 {
 361         makeFill(place, dp.holesize, 0,
 362                 MapNode(CONTENT_AIR), VMANIP_FLAG_DUNGEON_INSIDE);
 363 }
 364
 365
 366 void DungeonGen::makeDoor(v3s16 doorplace, v3s16 doordir)
 367 {
 368         makeHole(doorplace);
 369
 370 #ifdef DGEN_USE_TORCHES
 371         // Place torch (for testing)
 372         vm->m_data[vm->m_area.index(doorplace)] = MapNode(c_torch);
 373 #endif
 374 }
 375
 376
 377 void DungeonGen::makeCorridor(v3s16 doorplace,
 378                 v3s16 doordir, v3s16 &result_place, v3s16 &result_dir)
 379 {
 380         makeHole(doorplace);
 381         v3s16 p0 = doorplace;
 382         v3s16 dir = doordir;
 383         u32 length;
 384         /*if (random.next() % 2)
 385                 length = random.range(1, 13);
 386         else
 387                 length = random.range(1, 6);*/
 388         length = random.range(1, 13);
 389         u32 partlength = random.range(1, 13);
 390         u32 partcount = 0;
 391         s16 make_stairs = 0;
 392
 393         if (random.next() % 2 == 0 && partlength >= 3)
 394                 make_stairs = random.next() % 2 ? 1 : -1;
 395
 396         for (u32 i = 0; i < length; i++) {
 397                 v3s16 p = p0 + dir;
 398                 if (partcount != 0)
 399                         p.Y += make_stairs;
 400
 401                 if (vm->m_area.contains(p) == true &&
 402                         vm->m_area.contains(p + v3s16(0, 1, 0)) == true) {
 403                         if (make_stairs) {
 404                                 makeFill(p + v3s16(-1, -1, -1), dp.holesize + v3s16(2, 3, 2),
 405                                                 VMANIP_FLAG_DUNGEON_UNTOUCHABLE, MapNode(dp.c_cobble), 0);
 406                                 makeHole(p);
 407                                 makeHole(p - dir);
 408
 409                                 // TODO: fix stairs code so it works 100% (quite difficult)
 410
 411                                 // exclude stairs from the bottom step
 412                                 // exclude stairs from diagonal steps
 413                                 if (((dir.X ^ dir.Z) & 1) &&
 414                                         (((make_stairs ==  1) && i != 0) ||
 415                                         ((make_stairs == -1) && i != length - 1))) {
 416                                         // rotate face 180 deg if making stairs backwards
 417                                         int facedir = dir_to_facedir(dir * make_stairs);
 418
 419                                         u32 vi = vm->m_area.index(p.X - dir.X, p.Y - 1, p.Z - dir.Z);
 420                                         if (vm->m_data[vi].getContent() == dp.c_cobble)
 421                                                 vm->m_data[vi] = MapNode(dp.c_stair, 0, facedir);
 422
 423                                         vi = vm->m_area.index(p.X, p.Y, p.Z);
 424                                         if (vm->m_data[vi].getContent() == dp.c_cobble)
 425                                                 vm->m_data[vi] = MapNode(dp.c_stair, 0, facedir);
 426                                 }
 427                         } else {
 428                                 makeFill(p + v3s16(-1, -1, -1), dp.holesize + v3s16(2, 2, 2),
 429                                                 VMANIP_FLAG_DUNGEON_UNTOUCHABLE, MapNode(dp.c_cobble), 0);
 430                                 makeHole(p);
 431                         }
 432
 433                         p0 = p;
 434                 } else {
 435                         // Can't go here, turn away
 436                         dir = turn_xz(dir, random.range(0, 1));
 437                         make_stairs = -make_stairs;
 438                         partcount = 0;
 439                         partlength = random.range(1, length);
 440                         continue;
 441                 }
 442
 443                 partcount++;
 444                 if (partcount >= partlength) {
 445                         partcount = 0;
 446
 447                         dir = random_turn(random, dir);
 448
 449                         partlength = random.range(1,length);
 450
 451                         make_stairs = 0;
 452                         if (random.next() % 2 == 0 && partlength >= 3)
 453                                 make_stairs = random.next() % 2 ? 1 : -1;
 454                 }
 455         }
 456         result_place = p0;
 457         result_dir = dir;
 458 }
 459
 460
 461 bool DungeonGen::findPlaceForDoor(v3s16 &result_place, v3s16 &result_dir)
 462 {
 463         for (u32 i = 0; i < 100; i++)
 464         {
 465                 v3s16 p = m_pos + m_dir;
 466                 v3s16 p1 = p + v3s16(0, 1, 0);
 467                 if (vm->m_area.contains(p) == false
 468                  || vm->m_area.contains(p1) == false
 469                  || i % 4 == 0)
 470                 {
 471                         randomizeDir();
 472                         continue;
 473                 }
 474                 if (vm->getNodeNoExNoEmerge(p).getContent()  == dp.c_cobble
 475                  && vm->getNodeNoExNoEmerge(p1).getContent() == dp.c_cobble)
 476                 {
 477                         // Found wall, this is a good place!
 478                         result_place = p;
 479                         result_dir = m_dir;
 480                         // Randomize next direction
 481                         randomizeDir();
 482                         return true;
 483                 }
 484                 /*
 485                         Determine where to move next
 486                 */
 487                 // Jump one up if the actual space is there
 488                 if (vm->getNodeNoExNoEmerge(p+v3s16(0,0,0)).getContent() == dp.c_cobble
 489                  && vm->getNodeNoExNoEmerge(p+v3s16(0,1,0)).getContent() == CONTENT_AIR
 490                  && vm->getNodeNoExNoEmerge(p+v3s16(0,2,0)).getContent() == CONTENT_AIR)
 491                         p += v3s16(0,1,0);
 492                 // Jump one down if the actual space is there
 493                 if (vm->getNodeNoExNoEmerge(p+v3s16(0,1,0)).getContent() == dp.c_cobble
 494                  && vm->getNodeNoExNoEmerge(p+v3s16(0,0,0)).getContent() == CONTENT_AIR
 495                  && vm->getNodeNoExNoEmerge(p+v3s16(0,-1,0)).getContent() == CONTENT_AIR)
 496                         p += v3s16(0,-1,0);
 497                 // Check if walking is now possible
 498                 if (vm->getNodeNoExNoEmerge(p).getContent() != CONTENT_AIR
 499                  || vm->getNodeNoExNoEmerge(p+v3s16(0,1,0)).getContent() != CONTENT_AIR)
 500                 {
 501                         // Cannot continue walking here
 502                         randomizeDir();
 503                         continue;
 504                 }
 505                 // Move there
 506                 m_pos = p;
 507         }
 508         return false;
 509 }
 510
 511
 512 bool DungeonGen::findPlaceForRoomDoor(v3s16 roomsize, v3s16 &result_doorplace,
 513                 v3s16 &result_doordir, v3s16 &result_roomplace)
 514 {
 515         for (s16 trycount = 0; trycount < 30; trycount++)
 516         {
 517                 v3s16 doorplace;
 518                 v3s16 doordir;
 519                 bool r = findPlaceForDoor(doorplace, doordir);
 520                 if (r == false)
 521                         continue;
 522                 v3s16 roomplace;
 523                 // X east, Z north, Y up
 524 #if 1
 525                 if (doordir == v3s16(1, 0, 0)) // X+
 526                         roomplace = doorplace +
 527                                         v3s16(0, -1, random.range(-roomsize.Z + 2, -2));
 528                 if (doordir == v3s16(-1, 0, 0)) // X-
 529                         roomplace = doorplace +
 530                                         v3s16(-roomsize.X + 1, -1, random.range(-roomsize.Z + 2, -2));
 531                 if (doordir == v3s16(0, 0, 1)) // Z+
 532                         roomplace = doorplace +
 533                                         v3s16(random.range(-roomsize.X + 2, -2), -1, 0);
 534                 if (doordir == v3s16(0, 0, -1)) // Z-
 535                         roomplace = doorplace +
 536                                         v3s16(random.range(-roomsize.X + 2, -2), -1, -roomsize.Z + 1);
 537 #endif
 538 #if 0
 539                 if (doordir == v3s16(1, 0, 0)) // X+
 540                         roomplace = doorplace + v3s16(0, -1, -roomsize.Z / 2);
 541                 if (doordir == v3s16(-1, 0, 0)) // X-
 542                         roomplace = doorplace + v3s16(-roomsize.X+1,-1,-roomsize.Z / 2);
 543                 if (doordir == v3s16(0, 0, 1)) // Z+
 544                         roomplace = doorplace + v3s16(-roomsize.X / 2, -1, 0);
 545                 if (doordir == v3s16(0, 0, -1)) // Z-
 546                         roomplace = doorplace + v3s16(-roomsize.X / 2, -1, -roomsize.Z + 1);
 547 #endif
 548
 549                 // Check fit
 550                 bool fits = true;
 551                 for (s16 z = 1; z < roomsize.Z - 1; z++)
 552                 for (s16 y = 1; y < roomsize.Y - 1; y++)
 553                 for (s16 x = 1; x < roomsize.X - 1; x++)
 554                 {
 555                         v3s16 p = roomplace + v3s16(x, y, z);
 556                         if (vm->m_area.contains(p) == false)
 557                         {
 558                                 fits = false;
 559                                 break;
 560                         }
 561                         if (vm->m_flags[vm->m_area.index(p)]
 562                                         & VMANIP_FLAG_DUNGEON_INSIDE)
 563                         {
 564                                 fits = false;
 565                                 break;
 566                         }
 567                 }
 568                 if(fits == false)
 569                 {
 570                         // Find new place
 571                         continue;
 572                 }
 573                 result_doorplace = doorplace;
 574                 result_doordir   = doordir;
 575                 result_roomplace = roomplace;
 576                 return true;
 577         }
 578         return false;
 579 }
 580
 581
 582 v3s16 rand_ortho_dir(PseudoRandom &random, bool diagonal_dirs)
 583 {
 584         // Make diagonal directions somewhat rare
 585         if (diagonal_dirs && (random.next() % 4 == 0)) {
 586                 v3s16 dir;
 587                 int trycount = 0;
 588
 589                 do {
 590                         trycount++;
 591                         dir = v3s16(random.next() % 3 - 1, 0, random.next() % 3 - 1);
 592                 } while ((dir.X == 0 && dir.Z == 0) && trycount < 10);
 593
 594                 return dir;
 595         } else {
 596                 if (random.next() % 2 == 0)
 597                         return random.next() % 2 ? v3s16(-1, 0, 0) : v3s16(1, 0, 0);
 598                 else
 599                         return random.next() % 2 ? v3s16(0, 0, -1) : v3s16(0, 0, 1);
 600         }
 601 }
 602
 603
 604 v3s16 turn_xz(v3s16 olddir, int t)
 605 {
 606         v3s16 dir;
 607         if (t == 0)
 608         {
 609                 // Turn right
 610                 dir.X = olddir.Z;
 611                 dir.Z = -olddir.X;
 612                 dir.Y = olddir.Y;
 613         }
 614         else
 615         {
 616                 // Turn left
 617                 dir.X = -olddir.Z;
 618                 dir.Z = olddir.X;
 619                 dir.Y = olddir.Y;
 620         }
 621         return dir;
 622 }
 623
 624
 625 v3s16 random_turn(PseudoRandom &random, v3s16 olddir)
 626 {
 627         int turn = random.range(0, 2);
 628         v3s16 dir;
 629         if (turn == 0)
 630         {
 631                 // Go straight
 632                 dir = olddir;
 633         }
 634         else if (turn == 1)
 635                 // Turn right
 636                 dir = turn_xz(olddir, 0);
 637         else
 638                 // Turn left
 639                 dir = turn_xz(olddir, 1);
 640         return dir;
 641 }
 642
 643
 644 int dir_to_facedir(v3s16 d) {
 645         if (abs(d.X) > abs(d.Z))
 646                 return d.X < 0 ? 3 : 1;
 647         else
 648                 return d.Z < 0 ? 2 : 0;
 649 }