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