src/mapgen_flat.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_flat.h"
  41
  42
  43 FlagDesc flagdesc_mapgen_flat[] = {
  44         {"lakes", MGFLAT_LAKES},
  45         {"hills", MGFLAT_HILLS},
  46         {NULL,    0}
  47 };
  48
  49 ///////////////////////////////////////////////////////////////////////////////////////
  50
  51
  52 MapgenFlat::MapgenFlat(int mapgenid, MapgenParams *params, EmergeManager *emerge)
  53         : Mapgen(mapgenid, params, emerge)
  54 {
  55         this->m_emerge = emerge;
  56         this->bmgr     = emerge->biomemgr;
  57
  58         //// amount of elements to skip for the next index
  59         //// for noise/height/biome maps (not vmanip)
  60         this->ystride = csize.X;
  61         this->zstride = csize.X * (csize.Y + 2);
  62
  63         this->biomemap        = new u8[csize.X * csize.Z];
  64         this->heightmap       = new s16[csize.X * csize.Z];
  65         this->heatmap         = NULL;
  66         this->humidmap        = NULL;
  67
  68         MapgenFlatParams *sp = (MapgenFlatParams *)params->sparams;
  69         this->spflags = sp->spflags;
  70
  71         this->ground_level = sp->ground_level;
  72         this->large_cave_depth = sp->large_cave_depth;
  73         this->lake_threshold = sp->lake_threshold;
  74         this->lake_steepness = sp->lake_steepness;
  75         this->hill_threshold = sp->hill_threshold;
  76         this->hill_steepness = sp->hill_steepness;
  77
  78         //// 2D noise
  79         noise_terrain      = new Noise(&sp->np_terrain,      seed, csize.X, csize.Z);
  80         noise_filler_depth = new Noise(&sp->np_filler_depth, seed, csize.X, csize.Z);
  81
  82         //// 3D noise
  83         noise_cave1 = new Noise(&sp->np_cave1, seed, csize.X, csize.Y + 2, csize.Z);
  84         noise_cave2 = new Noise(&sp->np_cave2, seed, csize.X, csize.Y + 2, csize.Z);
  85
  86         //// Biome noise
  87         noise_heat           = new Noise(&params->np_biome_heat,           seed, csize.X, csize.Z);
  88         noise_humidity       = new Noise(&params->np_biome_humidity,       seed, csize.X, csize.Z);
  89         noise_heat_blend     = new Noise(&params->np_biome_heat_blend,     seed, csize.X, csize.Z);
  90         noise_humidity_blend = new Noise(&params->np_biome_humidity_blend, seed, csize.X, csize.Z);
  91
  92         //// Resolve nodes to be used
  93         INodeDefManager *ndef = emerge->ndef;
  94
  95         c_stone                = ndef->getId("mapgen_stone");
  96         c_water_source         = ndef->getId("mapgen_water_source");
  97         c_lava_source          = ndef->getId("mapgen_lava_source");
  98         c_desert_stone         = ndef->getId("mapgen_desert_stone");
  99         c_ice                  = ndef->getId("mapgen_ice");
 100         c_sandstone            = ndef->getId("mapgen_sandstone");
 101
 102         c_cobble               = ndef->getId("mapgen_cobble");
 103         c_stair_cobble         = ndef->getId("mapgen_stair_cobble");
 104         c_mossycobble          = ndef->getId("mapgen_mossycobble");
 105         c_sandstonebrick       = ndef->getId("mapgen_sandstonebrick");
 106         c_stair_sandstonebrick = ndef->getId("mapgen_stair_sandstonebrick");
 107
 108         if (c_ice == CONTENT_IGNORE)
 109                 c_ice = CONTENT_AIR;
 110         if (c_mossycobble == CONTENT_IGNORE)
 111                 c_mossycobble = c_cobble;
 112         if (c_stair_cobble == CONTENT_IGNORE)
 113                 c_stair_cobble = c_cobble;
 114         if (c_sandstonebrick == CONTENT_IGNORE)
 115                 c_sandstonebrick = c_sandstone;
 116         if (c_stair_sandstonebrick == CONTENT_IGNORE)
 117                 c_stair_sandstonebrick = c_sandstone;
 118 }
 119
 120
 121 MapgenFlat::~MapgenFlat()
 122 {
 123         delete noise_terrain;
 124         delete noise_filler_depth;
 125         delete noise_cave1;
 126         delete noise_cave2;
 127
 128         delete noise_heat;
 129         delete noise_humidity;
 130         delete noise_heat_blend;
 131         delete noise_humidity_blend;
 132
 133         delete[] heightmap;
 134         delete[] biomemap;
 135 }
 136
 137
 138 MapgenFlatParams::MapgenFlatParams()
 139 {
 140         spflags = 0;
 141
 142         ground_level = 8;
 143         large_cave_depth = -33;
 144         lake_threshold = -0.45;
 145         lake_steepness = 48.0;
 146         hill_threshold = 0.45;
 147         hill_steepness = 64.0;
 148
 149         np_terrain      = NoiseParams(0, 1,   v3f(600, 600, 600), 7244,  5, 0.6, 2.0);
 150         np_filler_depth = NoiseParams(0, 1.2, v3f(150, 150, 150), 261,   3, 0.7, 2.0);
 151         np_cave1        = NoiseParams(0, 12,  v3f(96,  96,  96),  52534, 4, 0.5, 2.0);
 152         np_cave2        = NoiseParams(0, 12,  v3f(96,  96,  96),  10325, 4, 0.5, 2.0);
 153 }
 154
 155
 156 void MapgenFlatParams::readParams(const Settings *settings)
 157 {
 158         settings->getFlagStrNoEx("mgflat_spflags", spflags, flagdesc_mapgen_flat);
 159
 160         settings->getS16NoEx("mgflat_ground_level",     ground_level);
 161         settings->getS16NoEx("mgflat_large_cave_depth", large_cave_depth);
 162         settings->getFloatNoEx("mgflat_lake_threshold", lake_threshold);
 163         settings->getFloatNoEx("mgflat_lake_steepness", lake_steepness);
 164         settings->getFloatNoEx("mgflat_hill_threshold", hill_threshold);
 165         settings->getFloatNoEx("mgflat_hill_steepness", hill_steepness);
 166
 167         settings->getNoiseParams("mgflat_np_terrain",      np_terrain);
 168         settings->getNoiseParams("mgflat_np_filler_depth", np_filler_depth);
 169         settings->getNoiseParams("mgflat_np_cave1",        np_cave1);
 170         settings->getNoiseParams("mgflat_np_cave2",        np_cave2);
 171 }
 172
 173
 174 void MapgenFlatParams::writeParams(Settings *settings) const
 175 {
 176         settings->setFlagStr("mgflat_spflags", spflags, flagdesc_mapgen_flat, U32_MAX);
 177
 178         settings->setS16("mgflat_ground_level",     ground_level);
 179         settings->setS16("mgflat_large_cave_depth", large_cave_depth);
 180         settings->setFloat("mgflat_lake_threshold", lake_threshold);
 181         settings->setFloat("mgflat_lake_steepness", lake_steepness);
 182         settings->setFloat("mgflat_hill_threshold", hill_threshold);
 183         settings->setFloat("mgflat_hill_steepness", hill_steepness);
 184
 185         settings->setNoiseParams("mgflat_np_terrain",      np_terrain);
 186         settings->setNoiseParams("mgflat_np_filler_depth", np_filler_depth);
 187         settings->setNoiseParams("mgflat_np_cave1",        np_cave1);
 188         settings->setNoiseParams("mgflat_np_cave2",        np_cave2);
 189 }
 190
 191
 192 /////////////////////////////////////////////////////////////////
 193
 194
 195 int MapgenFlat::getSpawnLevelAtPoint(v2s16 p)
 196 {
 197         s16 level_at_point = ground_level;
 198         float n_terrain = NoisePerlin2D(&noise_terrain->np, p.X, p.Y, seed);
 199
 200         if ((spflags & MGFLAT_LAKES) && n_terrain < lake_threshold) {
 201                 level_at_point = ground_level -
 202                         (lake_threshold - n_terrain) * lake_steepness;
 203         } else if ((spflags & MGFLAT_HILLS) && n_terrain > hill_threshold) {
 204                 level_at_point = ground_level +
 205                         (n_terrain - hill_threshold) * hill_steepness;
 206         }
 207
 208         if (ground_level < water_level)  // Ocean world, allow spawn in water
 209                 return MYMAX(level_at_point, water_level);
 210         else if (level_at_point > water_level)
 211                 return level_at_point;  // Spawn on land
 212         else
 213                 return MAX_MAP_GENERATION_LIMIT;  // Unsuitable spawn point
 214 }
 215
 216
 217 void MapgenFlat::makeChunk(BlockMakeData *data)
 218 {
 219         // Pre-conditions
 220         assert(data->vmanip);
 221         assert(data->nodedef);
 222         assert(data->blockpos_requested.X >= data->blockpos_min.X &&
 223                 data->blockpos_requested.Y >= data->blockpos_min.Y &&
 224                 data->blockpos_requested.Z >= data->blockpos_min.Z);
 225         assert(data->blockpos_requested.X <= data->blockpos_max.X &&
 226                 data->blockpos_requested.Y <= data->blockpos_max.Y &&
 227                 data->blockpos_requested.Z <= data->blockpos_max.Z);
 228
 229         this->generating = true;
 230         this->vm   = data->vmanip;
 231         this->ndef = data->nodedef;
 232         //TimeTaker t("makeChunk");
 233
 234         v3s16 blockpos_min = data->blockpos_min;
 235         v3s16 blockpos_max = data->blockpos_max;
 236         node_min = blockpos_min * MAP_BLOCKSIZE;
 237         node_max = (blockpos_max + v3s16(1, 1, 1)) * MAP_BLOCKSIZE - v3s16(1, 1, 1);
 238         full_node_min = (blockpos_min - 1) * MAP_BLOCKSIZE;
 239         full_node_max = (blockpos_max + 2) * MAP_BLOCKSIZE - v3s16(1, 1, 1);
 240
 241         blockseed = getBlockSeed2(full_node_min, seed);
 242
 243         // Make some noise
 244         calculateNoise();
 245
 246         // Generate base terrain, mountains, and ridges with initial heightmaps
 247         s16 stone_surface_max_y = generateTerrain();
 248
 249         // Create heightmap
 250         updateHeightmap(node_min, node_max);
 251
 252         // Create biomemap at heightmap surface
 253         bmgr->calcBiomes(csize.X, csize.Z, noise_heat->result,
 254                 noise_humidity->result, heightmap, biomemap);
 255
 256         // Actually place the biome-specific nodes
 257         MgStoneType stone_type = generateBiomes(noise_heat->result, noise_humidity->result);
 258
 259         if (flags & MG_CAVES)
 260                 generateCaves(stone_surface_max_y);
 261
 262         if ((flags & MG_DUNGEONS) && (stone_surface_max_y >= node_min.Y)) {
 263                 DungeonParams dp;
 264
 265                 dp.np_rarity  = nparams_dungeon_rarity;
 266                 dp.np_density = nparams_dungeon_density;
 267                 dp.np_wetness = nparams_dungeon_wetness;
 268                 dp.c_water    = c_water_source;
 269                 if (stone_type == STONE) {
 270                         dp.c_cobble = c_cobble;
 271                         dp.c_moss   = c_mossycobble;
 272                         dp.c_stair  = c_stair_cobble;
 273
 274                         dp.diagonal_dirs = false;
 275                         dp.mossratio     = 3.0;
 276                         dp.holesize      = v3s16(1, 2, 1);
 277                         dp.roomsize      = v3s16(0, 0, 0);
 278                         dp.notifytype    = GENNOTIFY_DUNGEON;
 279                 } else if (stone_type == DESERT_STONE) {
 280                         dp.c_cobble = c_desert_stone;
 281                         dp.c_moss   = c_desert_stone;
 282                         dp.c_stair  = c_desert_stone;
 283
 284                         dp.diagonal_dirs = true;
 285                         dp.mossratio     = 0.0;
 286                         dp.holesize      = v3s16(2, 3, 2);
 287                         dp.roomsize      = v3s16(2, 5, 2);
 288                         dp.notifytype    = GENNOTIFY_TEMPLE;
 289                 } else if (stone_type == SANDSTONE) {
 290                         dp.c_cobble = c_sandstonebrick;
 291                         dp.c_moss   = c_sandstonebrick;
 292                         dp.c_stair  = c_sandstonebrick;
 293
 294                         dp.diagonal_dirs = false;
 295                         dp.mossratio     = 0.0;
 296                         dp.holesize      = v3s16(2, 2, 2);
 297                         dp.roomsize      = v3s16(2, 0, 2);
 298                         dp.notifytype    = GENNOTIFY_DUNGEON;
 299                 }
 300
 301                 DungeonGen dgen(this, &dp);
 302                 dgen.generate(blockseed, full_node_min, full_node_max);
 303         }
 304
 305         // Generate the registered decorations
 306         if (flags & MG_DECORATIONS)
 307                 m_emerge->decomgr->placeAllDecos(this, blockseed, node_min, node_max);
 308
 309         // Generate the registered ores
 310         m_emerge->oremgr->placeAllOres(this, blockseed, node_min, node_max);
 311
 312         // Sprinkle some dust on top after everything else was generated
 313         dustTopNodes();
 314
 315         //printf("makeChunk: %dms\n", t.stop());
 316
 317         updateLiquid(&data->transforming_liquid, full_node_min, full_node_max);
 318
 319         if (flags & MG_LIGHT)
 320                 calcLighting(node_min - v3s16(0, 1, 0), node_max + v3s16(0, 1, 0),
 321                         full_node_min, full_node_max);
 322
 323         //setLighting(node_min - v3s16(1, 0, 1) * MAP_BLOCKSIZE,
 324         //                      node_max + v3s16(1, 0, 1) * MAP_BLOCKSIZE, 0xFF);
 325
 326         this->generating = false;
 327 }
 328
 329
 330 void MapgenFlat::calculateNoise()
 331 {
 332         //TimeTaker t("calculateNoise", NULL, PRECISION_MICRO);
 333         s16 x = node_min.X;
 334         s16 z = node_min.Z;
 335
 336         if ((spflags & MGFLAT_LAKES) || (spflags & MGFLAT_HILLS))
 337                 noise_terrain->perlinMap2D(x, z);
 338
 339         // Cave noises are calculated in generateCaves()
 340         // only if solid terrain is present in mapchunk
 341
 342         noise_filler_depth->perlinMap2D(x, z);
 343         noise_heat->perlinMap2D(x, z);
 344         noise_humidity->perlinMap2D(x, z);
 345         noise_heat_blend->perlinMap2D(x, z);
 346         noise_humidity_blend->perlinMap2D(x, z);
 347
 348         for (s32 i = 0; i < csize.X * csize.Z; i++) {
 349                 noise_heat->result[i] += noise_heat_blend->result[i];
 350                 noise_humidity->result[i] += noise_humidity_blend->result[i];
 351         }
 352
 353         heatmap = noise_heat->result;
 354         humidmap = noise_humidity->result;
 355         //printf("calculateNoise: %dus\n", t.stop());
 356 }
 357
 358
 359 s16 MapgenFlat::generateTerrain()
 360 {
 361         MapNode n_air(CONTENT_AIR);
 362         MapNode n_stone(c_stone);
 363         MapNode n_water(c_water_source);
 364
 365         v3s16 em = vm->m_area.getExtent();
 366         s16 stone_surface_max_y = -MAX_MAP_GENERATION_LIMIT;
 367         u32 ni2d = 0;
 368
 369         for (s16 z = node_min.Z; z <= node_max.Z; z++)
 370         for (s16 x = node_min.X; x <= node_max.X; x++, ni2d++) {
 371                 s16 stone_level = ground_level;
 372                 float n_terrain = 0.0f;
 373
 374                 if ((spflags & MGFLAT_LAKES) || (spflags & MGFLAT_HILLS))
 375                         n_terrain = noise_terrain->result[ni2d];
 376
 377                 if ((spflags & MGFLAT_LAKES) && n_terrain < lake_threshold) {
 378                         s16 depress = (lake_threshold - n_terrain) * lake_steepness;
 379                         stone_level = ground_level - depress;
 380                 } else if ((spflags & MGFLAT_HILLS) && n_terrain > hill_threshold) {
 381                         s16 rise = (n_terrain - hill_threshold) * hill_steepness;
 382                         stone_level = ground_level + rise;
 383                 }
 384
 385                 u32 vi = vm->m_area.index(x, node_min.Y - 1, z);
 386                 for (s16 y = node_min.Y - 1; y <= node_max.Y + 1; y++) {
 387                         if (vm->m_data[vi].getContent() == CONTENT_IGNORE) {
 388                                 if (y <= stone_level) {
 389                                         vm->m_data[vi] = n_stone;
 390                                         if (y > stone_surface_max_y)
 391                                                 stone_surface_max_y = y;
 392                                 } else if (y <= water_level) {
 393                                         vm->m_data[vi] = n_water;
 394                                 } else {
 395                                         vm->m_data[vi] = n_air;
 396                                 }
 397                         }
 398                         vm->m_area.add_y(em, vi, 1);
 399                 }
 400         }
 401
 402         return stone_surface_max_y;
 403 }
 404
 405
 406 MgStoneType MapgenFlat::generateBiomes(float *heat_map, float *humidity_map)
 407 {
 408         v3s16 em = vm->m_area.getExtent();
 409         u32 index = 0;
 410         MgStoneType stone_type = STONE;
 411
 412         for (s16 z = node_min.Z; z <= node_max.Z; z++)
 413         for (s16 x = node_min.X; x <= node_max.X; x++, index++) {
 414                 Biome *biome = NULL;
 415                 u16 depth_top = 0;
 416                 u16 base_filler = 0;
 417                 u16 depth_water_top = 0;
 418                 u32 vi = vm->m_area.index(x, node_max.Y, z);
 419
 420                 // Check node at base of mapchunk above, either a node of a previously
 421                 // generated mapchunk or if not, a node of overgenerated base terrain.
 422                 content_t c_above = vm->m_data[vi + em.X].getContent();
 423                 bool air_above = c_above == CONTENT_AIR;
 424                 bool water_above = c_above == c_water_source;
 425
 426                 // If there is air or water above enable top/filler placement, otherwise force
 427                 // nplaced to stone level by setting a number exceeding any possible filler depth.
 428                 u16 nplaced = (air_above || water_above) ? 0 : U16_MAX;
 429
 430
 431                 for (s16 y = node_max.Y; y >= node_min.Y; y--) {
 432                         content_t c = vm->m_data[vi].getContent();
 433
 434                         // Biome is recalculated each time an upper surface is detected while
 435                         // working down a column. The selected biome then remains in effect for
 436                         // all nodes below until the next surface and biome recalculation.
 437                         // Biome is recalculated:
 438                         // 1. At the surface of stone below air or water.
 439                         // 2. At the surface of water below air.
 440                         // 3. When stone or water is detected but biome has not yet been calculated.
 441                         if ((c == c_stone && (air_above || water_above || !biome)) ||
 442                                         (c == c_water_source && (air_above || !biome))) {
 443                                 biome = bmgr->getBiome(heat_map[index], humidity_map[index], y);
 444                                 depth_top = biome->depth_top;
 445                                 base_filler = MYMAX(depth_top + biome->depth_filler
 446                                         + noise_filler_depth->result[index], 0);
 447                                 depth_water_top = biome->depth_water_top;
 448
 449                                 // Detect stone type for dungeons during every biome calculation.
 450                                 // This is more efficient than detecting per-node and will not
 451                                 // miss any desert stone or sandstone biomes.
 452                                 if (biome->c_stone == c_desert_stone)
 453                                         stone_type = DESERT_STONE;
 454                                 else if (biome->c_stone == c_sandstone)
 455                                         stone_type = SANDSTONE;
 456                         }
 457
 458                         if (c == c_stone) {
 459                                 content_t c_below = vm->m_data[vi - em.X].getContent();
 460
 461                                 // If the node below isn't solid, make this node stone, so that
 462                                 // any top/filler nodes above are structurally supported.
 463                                 // This is done by aborting the cycle of top/filler placement
 464                                 // immediately by forcing nplaced to stone level.
 465                                 if (c_below == CONTENT_AIR || c_below == c_water_source)
 466                                         nplaced = U16_MAX;
 467
 468                                 if (nplaced < depth_top) {
 469                                         vm->m_data[vi] = MapNode(biome->c_top);
 470                                         nplaced++;
 471                                 } else if (nplaced < base_filler) {
 472                                         vm->m_data[vi] = MapNode(biome->c_filler);
 473                                         nplaced++;
 474                                 } else {
 475                                         vm->m_data[vi] = MapNode(biome->c_stone);
 476                                 }
 477
 478                                 air_above = false;
 479                                 water_above = false;
 480                         } else if (c == c_water_source) {
 481                                 vm->m_data[vi] = MapNode((y > (s32)(water_level - depth_water_top)) ?
 482                                                 biome->c_water_top : biome->c_water);
 483                                 nplaced = 0;  // Enable top/filler placement for next surface
 484                                 air_above = false;
 485                                 water_above = true;
 486                         } else if (c == CONTENT_AIR) {
 487                                 nplaced = 0;  // Enable top/filler placement for next surface
 488                                 air_above = true;
 489                                 water_above = false;
 490                         } else {  // Possible various nodes overgenerated from neighbouring mapchunks
 491                                 nplaced = U16_MAX;  // Disable top/filler placement
 492                                 air_above = false;
 493                                 water_above = false;
 494                         }
 495
 496                         vm->m_area.add_y(em, vi, -1);
 497                 }
 498         }
 499
 500         return stone_type;
 501 }
 502
 503
 504 void MapgenFlat::dustTopNodes()
 505 {
 506         if (node_max.Y < water_level)
 507                 return;
 508
 509         v3s16 em = vm->m_area.getExtent();
 510         u32 index = 0;
 511
 512         for (s16 z = node_min.Z; z <= node_max.Z; z++)
 513         for (s16 x = node_min.X; x <= node_max.X; x++, index++) {
 514                 Biome *biome = (Biome *)bmgr->getRaw(biomemap[index]);
 515
 516                 if (biome->c_dust == CONTENT_IGNORE)
 517                         continue;
 518
 519                 u32 vi = vm->m_area.index(x, full_node_max.Y, z);
 520                 content_t c_full_max = vm->m_data[vi].getContent();
 521                 s16 y_start;
 522
 523                 if (c_full_max == CONTENT_AIR) {
 524                         y_start = full_node_max.Y - 1;
 525                 } else if (c_full_max == CONTENT_IGNORE) {
 526                         vi = vm->m_area.index(x, node_max.Y + 1, z);
 527                         content_t c_max = vm->m_data[vi].getContent();
 528
 529                         if (c_max == CONTENT_AIR)
 530                                 y_start = node_max.Y;
 531                         else
 532                                 continue;
 533                 } else {
 534                         continue;
 535                 }
 536
 537                 vi = vm->m_area.index(x, y_start, z);
 538                 for (s16 y = y_start; y >= node_min.Y - 1; y--) {
 539                         if (vm->m_data[vi].getContent() != CONTENT_AIR)
 540                                 break;
 541
 542                         vm->m_area.add_y(em, vi, -1);
 543                 }
 544
 545                 content_t c = vm->m_data[vi].getContent();
 546                 if (!ndef->get(c).buildable_to && c != CONTENT_IGNORE && c != biome->c_dust) {
 547                         vm->m_area.add_y(em, vi, 1);
 548                         vm->m_data[vi] = MapNode(biome->c_dust);
 549                 }
 550         }
 551 }
 552
 553
 554 void MapgenFlat::generateCaves(s16 max_stone_y)
 555 {
 556         if (max_stone_y < node_min.Y)
 557                 return;
 558
 559         noise_cave1->perlinMap3D(node_min.X, node_min.Y - 1, node_min.Z);
 560         noise_cave2->perlinMap3D(node_min.X, node_min.Y - 1, node_min.Z);
 561
 562         v3s16 em = vm->m_area.getExtent();
 563         u32 index2d = 0;
 564
 565         for (s16 z = node_min.Z; z <= node_max.Z; z++)
 566         for (s16 x = node_min.X; x <= node_max.X; x++, index2d++) {
 567                 bool column_is_open = false;  // Is column open to overground
 568                 u32 vi = vm->m_area.index(x, node_max.Y + 1, z);
 569                 u32 index3d = (z - node_min.Z) * zstride + (csize.Y + 1) * ystride +
 570                         (x - node_min.X);
 571                 // Biome of column
 572                 Biome *biome = (Biome *)bmgr->getRaw(biomemap[index2d]);
 573
 574                 for (s16 y = node_max.Y + 1; y >= node_min.Y - 1;
 575                                 y--, index3d -= ystride, vm->m_area.add_y(em, vi, -1)) {
 576                         content_t c = vm->m_data[vi].getContent();
 577                         if (c == CONTENT_AIR || c == biome->c_water_top ||
 578                                         c == biome->c_water) {
 579                                 column_is_open = true;
 580                                 continue;
 581                         }
 582                         // Ground
 583                         float d1 = contour(noise_cave1->result[index3d]);
 584                         float d2 = contour(noise_cave2->result[index3d]);
 585                         if (d1 * d2 > 0.3f && ndef->get(c).is_ground_content) {
 586                                 // In tunnel and ground content, excavate
 587                                 vm->m_data[vi] = MapNode(CONTENT_AIR);
 588                         } else if (column_is_open &&
 589                                         (c == biome->c_filler || c == biome->c_stone)) {
 590                                 // Tunnel entrance floor
 591                                 vm->m_data[vi] = MapNode(biome->c_top);
 592                                 column_is_open = false;
 593                         } else {
 594                                 column_is_open = false;
 595                         }
 596                 }
 597         }
 598
 599         if (node_max.Y > large_cave_depth)
 600                 return;
 601
 602         PseudoRandom ps(blockseed + 21343);
 603         u32 bruises_count = ps.range(0, 2);
 604         for (u32 i = 0; i < bruises_count; i++) {
 605                 CaveV5 cave(this, &ps);
 606                 cave.makeCave(node_min, node_max, max_stone_y);
 607         }
 608 }