src/mapgen_v5.cpp

   1 /*
   2 Minetest
   3 Copyright (C) 2010-2015 kwolekr, Ryan Kwolek <kwolekr@minetest.net>
   4 Copyright (C) 2010-2015 paramat, Matt Gregory
   5
   6 This program is free software; you can redistribute it and/or modify
   7 it under the terms of the GNU Lesser General Public License as published by
   8 the Free Software Foundation; either version 2.1 of the License, or
   9 (at your option) any later version.
  10
  11 This program is distributed in the hope that it will be useful,
  12 but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 GNU Lesser General Public License for more details.
  15
  16 You should have received a copy of the GNU Lesser General Public License along
  17 with this program; if not, write to the Free Software Foundation, Inc.,
  18 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  19 */
  20
  21
  22 #include "mapgen.h"
  23 #include "voxel.h"
  24 #include "noise.h"
  25 #include "mapblock.h"
  26 #include "mapnode.h"
  27 #include "map.h"
  28 #include "content_sao.h"
  29 #include "nodedef.h"
  30 #include "voxelalgorithms.h"
  31 //#include "profiler.h" // For TimeTaker
  32 #include "settings.h" // For g_settings
  33 #include "emerge.h"
  34 #include "dungeongen.h"
  35 #include "cavegen.h"
  36 #include "treegen.h"
  37 #include "mg_biome.h"
  38 #include "mg_ore.h"
  39 #include "mg_decoration.h"
  40 #include "mapgen_v5.h"
  41
  42
  43 FlagDesc flagdesc_mapgen_v5[] = {
  44         {NULL,         0}
  45 };
  46
  47
  48 MapgenV5::MapgenV5(int mapgenid, MapgenParams *params, EmergeManager *emerge)
  49         : Mapgen(mapgenid, params, emerge)
  50 {
  51         this->m_emerge = emerge;
  52         this->bmgr     = emerge->biomemgr;
  53
  54         // amount of elements to skip for the next index
  55         // for noise/height/biome maps (not vmanip)
  56         this->ystride = csize.X;
  57         // 1-down overgeneration
  58         this->zstride_1d = csize.X * (csize.Y + 1);
  59
  60         this->biomemap  = new u8[csize.X * csize.Z];
  61         this->heightmap = new s16[csize.X * csize.Z];
  62         this->heatmap   = NULL;
  63         this->humidmap  = NULL;
  64
  65         MapgenV5Params *sp = (MapgenV5Params *)params->sparams;
  66         this->spflags      = sp->spflags;
  67
  68         // Terrain noise
  69         noise_filler_depth = new Noise(&sp->np_filler_depth, seed, csize.X, csize.Z);
  70         noise_factor       = new Noise(&sp->np_factor,       seed, csize.X, csize.Z);
  71         noise_height       = new Noise(&sp->np_height,       seed, csize.X, csize.Z);
  72
  73         // 3D terrain noise
  74         // 1-up 1-down overgeneration
  75         noise_ground = new Noise(&sp->np_ground, seed, csize.X, csize.Y + 2, csize.Z);
  76         // 1-down overgeneraion
  77         noise_cave1  = new Noise(&sp->np_cave1,  seed, csize.X, csize.Y + 1, csize.Z);
  78         noise_cave2  = new Noise(&sp->np_cave2,  seed, csize.X, csize.Y + 1, csize.Z);
  79
  80         // Biome noise
  81         noise_heat           = new Noise(&params->np_biome_heat,           seed, csize.X, csize.Z);
  82         noise_humidity       = new Noise(&params->np_biome_humidity,       seed, csize.X, csize.Z);
  83         noise_heat_blend     = new Noise(&params->np_biome_heat_blend,     seed, csize.X, csize.Z);
  84         noise_humidity_blend = new Noise(&params->np_biome_humidity_blend, seed, csize.X, csize.Z);
  85
  86         //// Resolve nodes to be used
  87         INodeDefManager *ndef = emerge->ndef;
  88
  89         c_stone                = ndef->getId("mapgen_stone");
  90         c_water_source         = ndef->getId("mapgen_water_source");
  91         c_lava_source          = ndef->getId("mapgen_lava_source");
  92         c_desert_stone         = ndef->getId("mapgen_desert_stone");
  93         c_ice                  = ndef->getId("mapgen_ice");
  94         c_sandstone            = ndef->getId("mapgen_sandstone");
  95
  96         c_cobble               = ndef->getId("mapgen_cobble");
  97         c_stair_cobble         = ndef->getId("mapgen_stair_cobble");
  98         c_mossycobble          = ndef->getId("mapgen_mossycobble");
  99         c_sandstonebrick       = ndef->getId("mapgen_sandstonebrick");
 100         c_stair_sandstonebrick = ndef->getId("mapgen_stair_sandstonebrick");
 101
 102         if (c_ice == CONTENT_IGNORE)
 103                 c_ice = CONTENT_AIR;
 104         if (c_mossycobble == CONTENT_IGNORE)
 105                 c_mossycobble = c_cobble;
 106         if (c_stair_cobble == CONTENT_IGNORE)
 107                 c_stair_cobble = c_cobble;
 108         if (c_sandstonebrick == CONTENT_IGNORE)
 109                 c_sandstonebrick = c_sandstone;
 110         if (c_stair_sandstonebrick == CONTENT_IGNORE)
 111                 c_stair_sandstonebrick = c_sandstone;
 112 }
 113
 114
 115 MapgenV5::~MapgenV5()
 116 {
 117         delete noise_filler_depth;
 118         delete noise_factor;
 119         delete noise_height;
 120         delete noise_cave1;
 121         delete noise_cave2;
 122         delete noise_ground;
 123
 124         delete noise_heat;
 125         delete noise_humidity;
 126         delete noise_heat_blend;
 127         delete noise_humidity_blend;
 128
 129         delete[] heightmap;
 130         delete[] biomemap;
 131 }
 132
 133
 134 MapgenV5Params::MapgenV5Params()
 135 {
 136         spflags = 0;
 137
 138         np_filler_depth = NoiseParams(0, 1,  v3f(150, 150, 150), 261,    4, 0.7,  2.0);
 139         np_factor       = NoiseParams(0, 1,  v3f(250, 250, 250), 920381, 3, 0.45, 2.0);
 140         np_height       = NoiseParams(0, 10, v3f(250, 250, 250), 84174,  4, 0.5,  2.0);
 141         np_cave1        = NoiseParams(0, 12, v3f(50,  50,  50),  52534,  4, 0.5,  2.0);
 142         np_cave2        = NoiseParams(0, 12, v3f(50,  50,  50),  10325,  4, 0.5,  2.0);
 143         np_ground       = NoiseParams(0, 40, v3f(80,  80,  80),  983240, 4, 0.55, 2.0, NOISE_FLAG_EASED);
 144 }
 145
 146
 147 //#define CAVE_NOISE_SCALE 12.0
 148 //#define CAVE_NOISE_THRESHOLD (1.5/CAVE_NOISE_SCALE) = 0.125
 149
 150
 151 void MapgenV5Params::readParams(const Settings *settings)
 152 {
 153         settings->getFlagStrNoEx("mgv5_spflags", spflags, flagdesc_mapgen_v5);
 154
 155         settings->getNoiseParams("mgv5_np_filler_depth", np_filler_depth);
 156         settings->getNoiseParams("mgv5_np_factor",       np_factor);
 157         settings->getNoiseParams("mgv5_np_height",       np_height);
 158         settings->getNoiseParams("mgv5_np_cave1",        np_cave1);
 159         settings->getNoiseParams("mgv5_np_cave2",        np_cave2);
 160         settings->getNoiseParams("mgv5_np_ground",       np_ground);
 161 }
 162
 163
 164 void MapgenV5Params::writeParams(Settings *settings) const
 165 {
 166         settings->setFlagStr("mgv5_spflags", spflags, flagdesc_mapgen_v5, U32_MAX);
 167
 168         settings->setNoiseParams("mgv5_np_filler_depth", np_filler_depth);
 169         settings->setNoiseParams("mgv5_np_factor",       np_factor);
 170         settings->setNoiseParams("mgv5_np_height",       np_height);
 171         settings->setNoiseParams("mgv5_np_cave1",        np_cave1);
 172         settings->setNoiseParams("mgv5_np_cave2",        np_cave2);
 173         settings->setNoiseParams("mgv5_np_ground",       np_ground);
 174 }
 175
 176
 177 int MapgenV5::getSpawnLevelAtPoint(v2s16 p)
 178 {
 179         //TimeTaker t("getGroundLevelAtPoint", NULL, PRECISION_MICRO);
 180
 181         float f = 0.55 + NoisePerlin2D(&noise_factor->np, p.X, p.Y, seed);
 182         if (f < 0.01)
 183                 f = 0.01;
 184         else if (f >= 1.0)
 185                 f *= 1.6;
 186         float h = NoisePerlin2D(&noise_height->np, p.X, p.Y, seed);
 187
 188         for (s16 y = 128; y >= -128; y--) {
 189                 float n_ground = NoisePerlin3D(&noise_ground->np, p.X, y, p.Y, seed);
 190
 191                 if (n_ground * f > y - h) {  // If solid
 192                         // If either top 2 nodes of search are solid this is inside a
 193                         // mountain or floatland with possibly no space for the player to spawn.
 194                         if (y >= 127) {
 195                                 return MAX_MAP_GENERATION_LIMIT;  // Unsuitable spawn point
 196                         } else {  // Ground below at least 2 nodes of empty space
 197                                 if (y <= water_level || y > water_level + 16)
 198                                         return MAX_MAP_GENERATION_LIMIT;  // Unsuitable spawn point
 199                                 else
 200                                         return y;
 201                         }
 202                 }
 203         }
 204
 205         //printf("getGroundLevelAtPoint: %dus\n", t.stop());
 206         return MAX_MAP_GENERATION_LIMIT;  // Unsuitable spawn position, no ground found
 207 }
 208
 209
 210 void MapgenV5::makeChunk(BlockMakeData *data)
 211 {
 212         // Pre-conditions
 213         assert(data->vmanip);
 214         assert(data->nodedef);
 215         assert(data->blockpos_requested.X >= data->blockpos_min.X &&
 216                 data->blockpos_requested.Y >= data->blockpos_min.Y &&
 217                 data->blockpos_requested.Z >= data->blockpos_min.Z);
 218         assert(data->blockpos_requested.X <= data->blockpos_max.X &&
 219                 data->blockpos_requested.Y <= data->blockpos_max.Y &&
 220                 data->blockpos_requested.Z <= data->blockpos_max.Z);
 221
 222         this->generating = true;
 223         this->vm   = data->vmanip;
 224         this->ndef = data->nodedef;
 225         //TimeTaker t("makeChunk");
 226
 227         v3s16 blockpos_min = data->blockpos_min;
 228         v3s16 blockpos_max = data->blockpos_max;
 229         node_min = blockpos_min * MAP_BLOCKSIZE;
 230         node_max = (blockpos_max + v3s16(1, 1, 1)) * MAP_BLOCKSIZE - v3s16(1, 1, 1);
 231         full_node_min = (blockpos_min - 1) * MAP_BLOCKSIZE;
 232         full_node_max = (blockpos_max + 2) * MAP_BLOCKSIZE - v3s16(1, 1, 1);
 233
 234         // Create a block-specific seed
 235         blockseed = getBlockSeed2(full_node_min, seed);
 236
 237         // Make some noise
 238         calculateNoise();
 239
 240         // Generate base terrain
 241         s16 stone_surface_max_y = generateBaseTerrain();
 242
 243         // Create heightmap
 244         updateHeightmap(node_min, node_max);
 245
 246         // Create biomemap at heightmap surface
 247         bmgr->calcBiomes(csize.X, csize.Z, noise_heat->result,
 248                 noise_humidity->result, heightmap, biomemap);
 249
 250         // Actually place the biome-specific nodes
 251         MgStoneType stone_type = generateBiomes(noise_heat->result, noise_humidity->result);
 252
 253         // Generate caves
 254         if ((flags & MG_CAVES) && (stone_surface_max_y >= node_min.Y))
 255                 generateCaves(stone_surface_max_y);
 256
 257         // Generate dungeons and desert temples
 258         if ((flags & MG_DUNGEONS) && (stone_surface_max_y >= node_min.Y)) {
 259                 DungeonParams dp;
 260
 261                 dp.np_rarity  = nparams_dungeon_rarity;
 262                 dp.np_density = nparams_dungeon_density;
 263                 dp.np_wetness = nparams_dungeon_wetness;
 264                 dp.c_water    = c_water_source;
 265                 if (stone_type == STONE) {
 266                         dp.c_cobble = c_cobble;
 267                         dp.c_moss   = c_mossycobble;
 268                         dp.c_stair  = c_stair_cobble;
 269
 270                         dp.diagonal_dirs = false;
 271                         dp.mossratio     = 3.0;
 272                         dp.holesize      = v3s16(1, 2, 1);
 273                         dp.roomsize      = v3s16(0, 0, 0);
 274                         dp.notifytype    = GENNOTIFY_DUNGEON;
 275                 } else if (stone_type == DESERT_STONE) {
 276                         dp.c_cobble = c_desert_stone;
 277                         dp.c_moss   = c_desert_stone;
 278                         dp.c_stair  = c_desert_stone;
 279
 280                         dp.diagonal_dirs = true;
 281                         dp.mossratio     = 0.0;
 282                         dp.holesize      = v3s16(2, 3, 2);
 283                         dp.roomsize      = v3s16(2, 5, 2);
 284                         dp.notifytype    = GENNOTIFY_TEMPLE;
 285                 } else if (stone_type == SANDSTONE) {
 286                         dp.c_cobble = c_sandstonebrick;
 287                         dp.c_moss   = c_sandstonebrick;
 288                         dp.c_stair  = c_sandstonebrick;
 289
 290                         dp.diagonal_dirs = false;
 291                         dp.mossratio     = 0.0;
 292                         dp.holesize      = v3s16(2, 2, 2);
 293                         dp.roomsize      = v3s16(2, 0, 2);
 294                         dp.notifytype    = GENNOTIFY_DUNGEON;
 295                 }
 296
 297                 DungeonGen dgen(this, &dp);
 298                 dgen.generate(blockseed, full_node_min, full_node_max);
 299         }
 300
 301         // Generate the registered decorations
 302         if (flags & MG_DECORATIONS)
 303                 m_emerge->decomgr->placeAllDecos(this, blockseed, node_min, node_max);
 304
 305         // Generate the registered ores
 306         m_emerge->oremgr->placeAllOres(this, blockseed, node_min, node_max);
 307
 308         // Sprinkle some dust on top after everything else was generated
 309         dustTopNodes();
 310
 311         //printf("makeChunk: %dms\n", t.stop());
 312
 313         // Add top and bottom side of water to transforming_liquid queue
 314         updateLiquid(&data->transforming_liquid, full_node_min, full_node_max);
 315
 316         // Calculate lighting
 317         if (flags & MG_LIGHT) {
 318                 calcLighting(node_min - v3s16(0, 1, 0), node_max + v3s16(0, 1, 0),
 319                         full_node_min, full_node_max);
 320         }
 321
 322         this->generating = false;
 323 }
 324
 325
 326 void MapgenV5::calculateNoise()
 327 {
 328         //TimeTaker t("calculateNoise", NULL, PRECISION_MICRO);
 329         s16 x = node_min.X;
 330         s16 y = node_min.Y - 1;
 331         s16 z = node_min.Z;
 332
 333         noise_factor->perlinMap2D(x, z);
 334         noise_height->perlinMap2D(x, z);
 335         noise_ground->perlinMap3D(x, y, z);
 336
 337         // Cave noises are calculated in generateCaves()
 338         // only if solid terrain is present in mapchunk
 339
 340         noise_filler_depth->perlinMap2D(x, z);
 341         noise_heat->perlinMap2D(x, z);
 342         noise_humidity->perlinMap2D(x, z);
 343         noise_heat_blend->perlinMap2D(x, z);
 344         noise_humidity_blend->perlinMap2D(x, z);
 345
 346         for (s32 i = 0; i < csize.X * csize.Z; i++) {
 347                 noise_heat->result[i] += noise_heat_blend->result[i];
 348                 noise_humidity->result[i] += noise_humidity_blend->result[i];
 349         }
 350
 351         heatmap = noise_heat->result;
 352         humidmap = noise_humidity->result;
 353         //printf("calculateNoise: %dus\n", t.stop());
 354 }
 355
 356
 357 //bool is_cave(u32 index) {
 358 //      double d1 = contour(noise_cave1->result[index]);
 359 //      double d2 = contour(noise_cave2->result[index]);
 360 //      return d1*d2 > CAVE_NOISE_THRESHOLD;
 361 //}
 362
 363 //bool val_is_ground(v3s16 p, u32 index, u32 index2d) {
 364 //      double f = 0.55 + noise_factor->result[index2d];
 365 //      if(f < 0.01)
 366 //              f = 0.01;
 367 //      else if(f >= 1.0)
 368 //              f *= 1.6;
 369 //      double h = WATER_LEVEL + 10 * noise_height->result[index2d];
 370 //      return (noise_ground->result[index] * f > (double)p.Y - h);
 371 //}
 372
 373
 374 int MapgenV5::generateBaseTerrain()
 375 {
 376         u32 index = 0;
 377         u32 index2d = 0;
 378         int stone_surface_max_y = -MAX_MAP_GENERATION_LIMIT;
 379
 380         for (s16 z=node_min.Z; z<=node_max.Z; z++) {
 381                 for (s16 y=node_min.Y - 1; y<=node_max.Y + 1; y++) {
 382                         u32 vi = vm->m_area.index(node_min.X, y, z);
 383                         for (s16 x=node_min.X; x<=node_max.X; x++, vi++, index++, index2d++) {
 384                                 if (vm->m_data[vi].getContent() != CONTENT_IGNORE)
 385                                         continue;
 386
 387                                 float f = 0.55 + noise_factor->result[index2d];
 388                                 if (f < 0.01)
 389                                         f = 0.01;
 390                                 else if (f >= 1.0)
 391                                         f *= 1.6;
 392                                 float h = noise_height->result[index2d];
 393
 394                                 if (noise_ground->result[index] * f < y - h) {
 395                                         if (y <= water_level)
 396                                                 vm->m_data[vi] = MapNode(c_water_source);
 397                                         else
 398                                                 vm->m_data[vi] = MapNode(CONTENT_AIR);
 399                                 } else {
 400                                         vm->m_data[vi] = MapNode(c_stone);
 401                                         if (y > stone_surface_max_y)
 402                                                 stone_surface_max_y = y;
 403                                 }
 404                         }
 405                         index2d -= ystride;
 406                 }
 407                 index2d += ystride;
 408         }
 409
 410         return stone_surface_max_y;
 411 }
 412
 413
 414 MgStoneType MapgenV5::generateBiomes(float *heat_map, float *humidity_map)
 415 {
 416         v3s16 em = vm->m_area.getExtent();
 417         u32 index = 0;
 418         MgStoneType stone_type = STONE;
 419
 420         for (s16 z = node_min.Z; z <= node_max.Z; z++)
 421         for (s16 x = node_min.X; x <= node_max.X; x++, index++) {
 422                 Biome *biome = NULL;
 423                 u16 depth_top = 0;
 424                 u16 base_filler = 0;
 425                 u16 depth_water_top = 0;
 426                 u32 vi = vm->m_area.index(x, node_max.Y, z);
 427
 428                 // Check node at base of mapchunk above, either a node of a previously
 429                 // generated mapchunk or if not, a node of overgenerated base terrain.
 430                 content_t c_above = vm->m_data[vi + em.X].getContent();
 431                 bool air_above = c_above == CONTENT_AIR;
 432                 bool water_above = c_above == c_water_source;
 433
 434                 // If there is air or water above enable top/filler placement, otherwise force
 435                 // nplaced to stone level by setting a number exceeding any possible filler depth.
 436                 u16 nplaced = (air_above || water_above) ? 0 : U16_MAX;
 437
 438                 for (s16 y = node_max.Y; y >= node_min.Y; y--) {
 439                         content_t c = vm->m_data[vi].getContent();
 440
 441                         // Biome is recalculated each time an upper surface is detected while
 442                         // working down a column. The selected biome then remains in effect for
 443                         // all nodes below until the next surface and biome recalculation.
 444                         // Biome is recalculated:
 445                         // 1. At the surface of stone below air or water.
 446                         // 2. At the surface of water below air.
 447                         // 3. When stone or water is detected but biome has not yet been calculated.
 448                         if ((c == c_stone && (air_above || water_above || !biome)) ||
 449                                         (c == c_water_source && (air_above || !biome))) {
 450                                 biome = bmgr->getBiome(heat_map[index], humidity_map[index], y);
 451                                 depth_top = biome->depth_top;
 452                                 base_filler = MYMAX(depth_top + biome->depth_filler
 453                                                 + noise_filler_depth->result[index], 0);
 454                                 depth_water_top = biome->depth_water_top;
 455
 456                                 // Detect stone type for dungeons during every biome calculation.
 457                                 // This is more efficient than detecting per-node and will not
 458                                 // miss any desert stone or sandstone biomes.
 459                                 if (biome->c_stone == c_desert_stone)
 460                                         stone_type = DESERT_STONE;
 461                                 else if (biome->c_stone == c_sandstone)
 462                                         stone_type = SANDSTONE;
 463                         }
 464
 465                         if (c == c_stone) {
 466                                 content_t c_below = vm->m_data[vi - em.X].getContent();
 467
 468                                 // If the node below isn't solid, make this node stone, so that
 469                                 // any top/filler nodes above are structurally supported.
 470                                 // This is done by aborting the cycle of top/filler placement
 471                                 // immediately by forcing nplaced to stone level.
 472                                 if (c_below == CONTENT_AIR || c_below == c_water_source)
 473                                         nplaced = U16_MAX;
 474
 475                                 if (nplaced < depth_top) {
 476                                         vm->m_data[vi] = MapNode(biome->c_top);
 477                                         nplaced++;
 478                                 } else if (nplaced < base_filler) {
 479                                         vm->m_data[vi] = MapNode(biome->c_filler);
 480                                         nplaced++;
 481                                 } else {
 482                                         vm->m_data[vi] = MapNode(biome->c_stone);
 483                                 }
 484
 485                                 air_above = false;
 486                                 water_above = false;
 487                         } else if (c == c_water_source) {
 488                                 vm->m_data[vi] = MapNode((y > (s32)(water_level - depth_water_top)) ?
 489                                                 biome->c_water_top : biome->c_water);
 490                                 nplaced = 0;  // Enable top/filler placement for next surface
 491                                 air_above = false;
 492                                 water_above = true;
 493                         } else if (c == CONTENT_AIR) {
 494                                 nplaced = 0;  // Enable top/filler placement for next surface
 495                                 air_above = true;
 496                                 water_above = false;
 497                         } else {  // Possible various nodes overgenerated from neighbouring mapchunks
 498                                 nplaced = U16_MAX;  // Disable top/filler placement
 499                                 air_above = false;
 500                                 water_above = false;
 501                         }
 502
 503                         vm->m_area.add_y(em, vi, -1);
 504                 }
 505         }
 506
 507         return stone_type;
 508 }
 509
 510
 511 void MapgenV5::dustTopNodes()
 512 {
 513         if (node_max.Y < water_level)
 514                 return;
 515
 516         v3s16 em = vm->m_area.getExtent();
 517         u32 index = 0;
 518
 519         for (s16 z = node_min.Z; z <= node_max.Z; z++)
 520         for (s16 x = node_min.X; x <= node_max.X; x++, index++) {
 521                 Biome *biome = (Biome *)bmgr->getRaw(biomemap[index]);
 522
 523                 if (biome->c_dust == CONTENT_IGNORE)
 524                         continue;
 525
 526                 u32 vi = vm->m_area.index(x, full_node_max.Y, z);
 527                 content_t c_full_max = vm->m_data[vi].getContent();
 528                 s16 y_start;
 529
 530                 if (c_full_max == CONTENT_AIR) {
 531                         y_start = full_node_max.Y - 1;
 532                 } else if (c_full_max == CONTENT_IGNORE) {
 533                         vi = vm->m_area.index(x, node_max.Y + 1, z);
 534                         content_t c_max = vm->m_data[vi].getContent();
 535
 536                         if (c_max == CONTENT_AIR)
 537                                 y_start = node_max.Y;
 538                         else
 539                                 continue;
 540                 } else {
 541                         continue;
 542                 }
 543
 544                 vi = vm->m_area.index(x, y_start, z);
 545                 for (s16 y = y_start; y >= node_min.Y - 1; y--) {
 546                         if (vm->m_data[vi].getContent() != CONTENT_AIR)
 547                                 break;
 548
 549                         vm->m_area.add_y(em, vi, -1);
 550                 }
 551
 552                 content_t c = vm->m_data[vi].getContent();
 553                 if (!ndef->get(c).buildable_to && c != CONTENT_IGNORE && c != biome->c_dust) {
 554                         vm->m_area.add_y(em, vi, 1);
 555                         vm->m_data[vi] = MapNode(biome->c_dust);
 556                 }
 557         }
 558 }
 559
 560
 561 void MapgenV5::generateCaves(int max_stone_y)
 562 {
 563         if (max_stone_y < node_min.Y)
 564                 return;
 565
 566         noise_cave1->perlinMap3D(node_min.X, node_min.Y - 1, node_min.Z);
 567         noise_cave2->perlinMap3D(node_min.X, node_min.Y - 1, node_min.Z);
 568
 569         v3s16 em = vm->m_area.getExtent();
 570         u32 index2d = 0;
 571
 572         for (s16 z = node_min.Z; z <= node_max.Z; z++)
 573         for (s16 x = node_min.X; x <= node_max.X; x++, index2d++) {
 574                 bool column_is_open = false;  // Is column open to overground
 575                 bool is_tunnel = false;  // Is tunnel or tunnel floor
 576                 // Indexes at column top (node_max.Y)
 577                 u32 vi = vm->m_area.index(x, node_max.Y, z);
 578                 u32 index3d = (z - node_min.Z) * zstride_1d + csize.Y * ystride +
 579                         (x - node_min.X);
 580                 // Biome of column
 581                 Biome *biome = (Biome *)bmgr->getRaw(biomemap[index2d]);
 582
 583                 // Don't excavate the overgenerated stone at node_max.Y + 1,
 584                 // this creates a 'roof' over the tunnel, preventing light in
 585                 // tunnels at mapchunk borders when generating mapchunks upwards.
 586                 // This 'roof' is removed when the mapchunk above is generated.
 587                 for (s16 y = node_max.Y; y >= node_min.Y - 1; y--,
 588                                 index3d -= ystride,
 589                                 vm->m_area.add_y(em, vi, -1)) {
 590
 591                         content_t c = vm->m_data[vi].getContent();
 592                         if (c == CONTENT_AIR || c == biome->c_water_top ||
 593                                         c == biome->c_water) {
 594                                 column_is_open = true;
 595                                 continue;
 596                         }
 597                         // Ground
 598                         float d1 = contour(noise_cave1->result[index3d]);
 599                         float d2 = contour(noise_cave2->result[index3d]);
 600
 601                         if (d1 * d2 > 0.125f && ndef->get(c).is_ground_content) {
 602                                 // In tunnel and ground content, excavate
 603                                 vm->m_data[vi] = MapNode(CONTENT_AIR);
 604                                 is_tunnel = true;
 605                         } else {
 606                                 // Not in tunnel or not ground content
 607                                 if (is_tunnel && column_is_open &&
 608                                                 (c == biome->c_filler || c == biome->c_stone))
 609                                         // Tunnel entrance floor
 610                                         vm->m_data[vi] = MapNode(biome->c_top);
 611
 612                                 column_is_open = false;
 613                                 is_tunnel = false;
 614                         }
 615                 }
 616         }
 617
 618         if (node_max.Y > MGV5_LARGE_CAVE_DEPTH)
 619                 return;
 620
 621         PseudoRandom ps(blockseed + 21343);
 622         u32 bruises_count = ps.range(0, 2);
 623         for (u32 i = 0; i < bruises_count; i++) {
 624                 CaveV5 cave(this, &ps);
 625                 cave.makeCave(node_min, node_max, max_stone_y);
 626         }
 627 }