src/mapgen_v5.cpp

   1 /*
   2 Minetest
   3 Copyright (C) 2010-2013 kwolekr, Ryan Kwolek <kwolekr@minetest.net>
   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
  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 "content_sao.h"
  28 #include "nodedef.h"
  29 #include "voxelalgorithms.h"
  30 #include "settings.h" // For g_settings
  31 #include "emerge.h"
  32 #include "dungeongen.h"
  33 #include "cavegen.h"
  34 #include "treegen.h"
  35 #include "mg_biome.h"
  36 #include "mg_ore.h"
  37 #include "mg_decoration.h"
  38 #include "mapgen_v5.h"
  39 #include "util/directiontables.h"
  40
  41
  42 FlagDesc flagdesc_mapgen_v5[] = {
  43         {NULL,         0}
  44 };
  45
  46
  47 MapgenV5::MapgenV5(int mapgenid, MapgenParams *params, EmergeManager *emerge)
  48         : Mapgen(mapgenid, params, emerge)
  49 {
  50         this->m_emerge = emerge;
  51         this->bmgr     = emerge->biomemgr;
  52
  53         // amount of elements to skip for the next index
  54         // for noise/height/biome maps (not vmanip)
  55         this->ystride = csize.X;
  56         this->zstride = csize.X * (csize.Y + 2);
  57
  58         this->biomemap  = new u8[csize.X * csize.Z];
  59         this->heightmap = new s16[csize.X * csize.Z];
  60         this->heatmap   = NULL;
  61         this->humidmap  = NULL;
  62
  63         MapgenV5Params *sp = (MapgenV5Params *)params->sparams;
  64         this->spflags      = sp->spflags;
  65
  66         // Terrain noise
  67         noise_filler_depth = new Noise(&sp->np_filler_depth, seed, csize.X, csize.Z);
  68         noise_factor       = new Noise(&sp->np_factor,       seed, csize.X, csize.Z);
  69         noise_height       = new Noise(&sp->np_height,       seed, csize.X, csize.Z);
  70
  71         // 3D terrain noise
  72         noise_cave1  = new Noise(&sp->np_cave1,  seed, csize.X, csize.Y + 2, csize.Z);
  73         noise_cave2  = new Noise(&sp->np_cave2,  seed, csize.X, csize.Y + 2, csize.Z);
  74         noise_ground = new Noise(&sp->np_ground, seed, csize.X, csize.Y + 2, csize.Z);
  75
  76         // Biome noise
  77         noise_heat           = new Noise(&params->np_biome_heat,           seed, csize.X, csize.Z);
  78         noise_humidity       = new Noise(&params->np_biome_humidity,       seed, csize.X, csize.Z);
  79         noise_heat_blend     = new Noise(&params->np_biome_heat_blend,     seed, csize.X, csize.Z);
  80         noise_humidity_blend = new Noise(&params->np_biome_humidity_blend, seed, csize.X, csize.Z);
  81
  82         //// Resolve nodes to be used
  83         INodeDefManager *ndef = emerge->ndef;
  84
  85         c_stone                = ndef->getId("mapgen_stone");
  86         c_water_source         = ndef->getId("mapgen_water_source");
  87         c_lava_source          = ndef->getId("mapgen_lava_source");
  88         c_desert_stone         = ndef->getId("mapgen_desert_stone");
  89         c_ice                  = ndef->getId("mapgen_ice");
  90         c_sandstone            = ndef->getId("mapgen_sandstone");
  91
  92         c_cobble               = ndef->getId("mapgen_cobble");
  93         c_stair_cobble         = ndef->getId("mapgen_stair_cobble");
  94         c_mossycobble          = ndef->getId("mapgen_mossycobble");
  95         c_sandstonebrick       = ndef->getId("mapgen_sandstonebrick");
  96         c_stair_sandstonebrick = ndef->getId("mapgen_stair_sandstonebrick");
  97
  98         if (c_ice == CONTENT_IGNORE)
  99                 c_ice = CONTENT_AIR;
 100         if (c_mossycobble == CONTENT_IGNORE)
 101                 c_mossycobble = c_cobble;
 102         if (c_stair_cobble == CONTENT_IGNORE)
 103                 c_stair_cobble = c_cobble;
 104         if (c_sandstonebrick == CONTENT_IGNORE)
 105                 c_sandstonebrick = c_sandstone;
 106         if (c_stair_sandstonebrick == CONTENT_IGNORE)
 107                 c_stair_sandstonebrick = c_sandstone;
 108 }
 109
 110
 111 MapgenV5::~MapgenV5()
 112 {
 113         delete noise_filler_depth;
 114         delete noise_factor;
 115         delete noise_height;
 116         delete noise_cave1;
 117         delete noise_cave2;
 118         delete noise_ground;
 119
 120         delete noise_heat;
 121         delete noise_humidity;
 122         delete noise_heat_blend;
 123         delete noise_humidity_blend;
 124
 125         delete[] heightmap;
 126         delete[] biomemap;
 127 }
 128
 129
 130 MapgenV5Params::MapgenV5Params()
 131 {
 132         spflags = 0;
 133
 134         np_filler_depth = NoiseParams(0, 1,  v3f(150, 150, 150), 261,    4, 0.7,  2.0);
 135         np_factor       = NoiseParams(0, 1,  v3f(250, 250, 250), 920381, 3, 0.45, 2.0);
 136         np_height       = NoiseParams(0, 10, v3f(250, 250, 250), 84174,  4, 0.5,  2.0);
 137         np_cave1        = NoiseParams(0, 12, v3f(50,  50,  50),  52534,  4, 0.5,  2.0);
 138         np_cave2        = NoiseParams(0, 12, v3f(50,  50,  50),  10325,  4, 0.5,  2.0);
 139         np_ground       = NoiseParams(0, 40, v3f(80,  80,  80),  983240, 4, 0.55, 2.0, NOISE_FLAG_EASED);
 140 }
 141
 142
 143 //#define CAVE_NOISE_SCALE 12.0
 144 //#define CAVE_NOISE_THRESHOLD (1.5/CAVE_NOISE_SCALE) = 0.125
 145
 146
 147 void MapgenV5Params::readParams(const Settings *settings)
 148 {
 149         settings->getFlagStrNoEx("mgv5_spflags", spflags, flagdesc_mapgen_v5);
 150
 151         settings->getNoiseParams("mgv5_np_filler_depth", np_filler_depth);
 152         settings->getNoiseParams("mgv5_np_factor",       np_factor);
 153         settings->getNoiseParams("mgv5_np_height",       np_height);
 154         settings->getNoiseParams("mgv5_np_cave1",        np_cave1);
 155         settings->getNoiseParams("mgv5_np_cave2",        np_cave2);
 156         settings->getNoiseParams("mgv5_np_ground",       np_ground);
 157 }
 158
 159
 160 void MapgenV5Params::writeParams(Settings *settings) const
 161 {
 162         settings->setFlagStr("mgv5_spflags", spflags, flagdesc_mapgen_v5, (u32)-1);
 163
 164         settings->setNoiseParams("mgv5_np_filler_depth", np_filler_depth);
 165         settings->setNoiseParams("mgv5_np_factor",       np_factor);
 166         settings->setNoiseParams("mgv5_np_height",       np_height);
 167         settings->setNoiseParams("mgv5_np_cave1",        np_cave1);
 168         settings->setNoiseParams("mgv5_np_cave2",        np_cave2);
 169         settings->setNoiseParams("mgv5_np_ground",       np_ground);
 170 }
 171
 172
 173 int MapgenV5::getGroundLevelAtPoint(v2s16 p)
 174 {
 175         //TimeTaker t("getGroundLevelAtPoint", NULL, PRECISION_MICRO);
 176
 177         float f = 0.55 + NoisePerlin2D(&noise_factor->np, p.X, p.Y, seed);
 178         if (f < 0.01)
 179                 f = 0.01;
 180         else if (f >= 1.0)
 181                 f *= 1.6;
 182         float h = NoisePerlin2D(&noise_height->np, p.X, p.Y, seed);
 183
 184         s16 search_top = water_level + 15;
 185         s16 search_base = water_level;
 186
 187         s16 level = -31000;
 188         for (s16 y = search_top; y >= search_base; y--) {
 189                 float n_ground = NoisePerlin3D(&noise_ground->np, p.X, y, p.Y, seed);
 190                 if (n_ground * f > y - h) {
 191                         if (y >= search_top - 7)
 192                                 break;
 193                         else
 194                                 level = y;
 195                                 break;
 196                 }
 197         }
 198
 199         //printf("getGroundLevelAtPoint: %dus\n", t.stop());
 200         return level;
 201 }
 202
 203
 204 void MapgenV5::makeChunk(BlockMakeData *data)
 205 {
 206         // Pre-conditions
 207         assert(data->vmanip);
 208         assert(data->nodedef);
 209         assert(data->blockpos_requested.X >= data->blockpos_min.X &&
 210                 data->blockpos_requested.Y >= data->blockpos_min.Y &&
 211                 data->blockpos_requested.Z >= data->blockpos_min.Z);
 212         assert(data->blockpos_requested.X <= data->blockpos_max.X &&
 213                 data->blockpos_requested.Y <= data->blockpos_max.Y &&
 214                 data->blockpos_requested.Z <= data->blockpos_max.Z);
 215
 216         generating = true;
 217         vm   = data->vmanip;
 218         ndef = data->nodedef;
 219         //TimeTaker t("makeChunk");
 220
 221         v3s16 blockpos_min = data->blockpos_min;
 222         v3s16 blockpos_max = data->blockpos_max;
 223         node_min = blockpos_min * MAP_BLOCKSIZE;
 224         node_max = (blockpos_max + v3s16(1, 1, 1)) * MAP_BLOCKSIZE - v3s16(1, 1, 1);
 225         full_node_min = (blockpos_min - 1) * MAP_BLOCKSIZE;
 226         full_node_max = (blockpos_max + 2) * MAP_BLOCKSIZE - v3s16(1, 1, 1);
 227
 228         // Create a block-specific seed
 229         blockseed = getBlockSeed2(full_node_min, seed);
 230
 231         // Make some noise
 232         calculateNoise();
 233
 234         // Generate base terrain
 235         s16 stone_surface_max_y = generateBaseTerrain();
 236
 237         // Create heightmap
 238         updateHeightmap(node_min, node_max);
 239
 240         // Create biomemap at heightmap surface
 241         bmgr->calcBiomes(csize.X, csize.Z, noise_heat->result,
 242                 noise_humidity->result, heightmap, biomemap);
 243
 244         // Actually place the biome-specific nodes
 245         MgStoneType stone_type = generateBiomes(noise_heat->result, noise_humidity->result);
 246
 247         // Generate caves
 248         if ((flags & MG_CAVES) && (stone_surface_max_y >= node_min.Y))
 249                 generateCaves(stone_surface_max_y);
 250
 251         // Generate dungeons and desert temples
 252         if ((flags & MG_DUNGEONS) && (stone_surface_max_y >= node_min.Y)) {
 253                 DungeonParams dp;
 254
 255                 dp.np_rarity  = nparams_dungeon_rarity;
 256                 dp.np_density = nparams_dungeon_density;
 257                 dp.np_wetness = nparams_dungeon_wetness;
 258                 dp.c_water    = c_water_source;
 259                 if (stone_type == STONE) {
 260                         dp.c_cobble = c_cobble;
 261                         dp.c_moss   = c_mossycobble;
 262                         dp.c_stair  = c_stair_cobble;
 263
 264                         dp.diagonal_dirs = false;
 265                         dp.mossratio     = 3.0;
 266                         dp.holesize      = v3s16(1, 2, 1);
 267                         dp.roomsize      = v3s16(0, 0, 0);
 268                         dp.notifytype    = GENNOTIFY_DUNGEON;
 269                 } else if (stone_type == DESERT_STONE) {
 270                         dp.c_cobble = c_desert_stone;
 271                         dp.c_moss   = c_desert_stone;
 272                         dp.c_stair  = c_desert_stone;
 273
 274                         dp.diagonal_dirs = true;
 275                         dp.mossratio     = 0.0;
 276                         dp.holesize      = v3s16(2, 3, 2);
 277                         dp.roomsize      = v3s16(2, 5, 2);
 278                         dp.notifytype    = GENNOTIFY_TEMPLE;
 279                 } else if (stone_type == SANDSTONE) {
 280                         dp.c_cobble = c_sandstonebrick;
 281                         dp.c_moss   = c_sandstonebrick;
 282                         dp.c_stair  = c_sandstonebrick;
 283
 284                         dp.diagonal_dirs = false;
 285                         dp.mossratio     = 0.0;
 286                         dp.holesize      = v3s16(2, 2, 2);
 287                         dp.roomsize      = v3s16(2, 0, 2);
 288                         dp.notifytype    = GENNOTIFY_DUNGEON;
 289                 }
 290
 291                 DungeonGen dgen(this, &dp);
 292                 dgen.generate(blockseed, full_node_min, full_node_max);
 293         }
 294
 295         // Generate the registered decorations
 296         m_emerge->decomgr->placeAllDecos(this, blockseed, node_min, node_max);
 297
 298         // Generate the registered ores
 299         m_emerge->oremgr->placeAllOres(this, blockseed, node_min, node_max);
 300
 301         // Sprinkle some dust on top after everything else was generated
 302         dustTopNodes();
 303
 304         //printf("makeChunk: %dms\n", t.stop());
 305
 306         // Add top and bottom side of water to transforming_liquid queue
 307         updateLiquid(&data->transforming_liquid, full_node_min, full_node_max);
 308
 309         // Calculate lighting
 310         if (flags & MG_LIGHT) {
 311                 calcLighting(node_min - v3s16(0, 1, 0), node_max + v3s16(0, 1, 0),
 312                         full_node_min, full_node_max);
 313         }
 314
 315         this->generating = false;
 316 }
 317
 318
 319 void MapgenV5::calculateNoise()
 320 {
 321         //TimeTaker t("calculateNoise", NULL, PRECISION_MICRO);
 322         int x = node_min.X;
 323         int y = node_min.Y - 1;
 324         int z = node_min.Z;
 325
 326         noise_factor->perlinMap2D(x, z);
 327         noise_height->perlinMap2D(x, z);
 328         noise_ground->perlinMap3D(x, y, z);
 329
 330         if (flags & MG_CAVES) {
 331                 noise_cave1->perlinMap3D(x, y, z);
 332                 noise_cave2->perlinMap3D(x, y, z);
 333         }
 334
 335         noise_filler_depth->perlinMap2D(x, z);
 336         noise_heat->perlinMap2D(x, z);
 337         noise_humidity->perlinMap2D(x, z);
 338         noise_heat_blend->perlinMap2D(x, z);
 339         noise_humidity_blend->perlinMap2D(x, z);
 340
 341         for (s32 i = 0; i < csize.X * csize.Z; i++) {
 342                 noise_heat->result[i] += noise_heat_blend->result[i];
 343                 noise_humidity->result[i] += noise_humidity_blend->result[i];
 344         }
 345
 346         heatmap = noise_heat->result;
 347         humidmap = noise_humidity->result;
 348         //printf("calculateNoise: %dus\n", t.stop());
 349 }
 350
 351
 352 //bool is_cave(u32 index) {
 353 //      double d1 = contour(noise_cave1->result[index]);
 354 //      double d2 = contour(noise_cave2->result[index]);
 355 //      return d1*d2 > CAVE_NOISE_THRESHOLD;
 356 //}
 357
 358 //bool val_is_ground(v3s16 p, u32 index, u32 index2d) {
 359 //      double f = 0.55 + noise_factor->result[index2d];
 360 //      if(f < 0.01)
 361 //              f = 0.01;
 362 //      else if(f >= 1.0)
 363 //              f *= 1.6;
 364 //      double h = WATER_LEVEL + 10 * noise_height->result[index2d];
 365 //      return (noise_ground->result[index] * f > (double)p.Y - h);
 366 //}
 367
 368
 369 int MapgenV5::generateBaseTerrain()
 370 {
 371         u32 index = 0;
 372         u32 index2d = 0;
 373         int stone_surface_max_y = -MAP_GENERATION_LIMIT;
 374
 375         for (s16 z=node_min.Z; z<=node_max.Z; z++) {
 376                 for (s16 y=node_min.Y - 1; y<=node_max.Y + 1; y++) {
 377                         u32 i = vm->m_area.index(node_min.X, y, z);
 378                         for (s16 x=node_min.X; x<=node_max.X; x++, i++, index++, index2d++) {
 379                                 if (vm->m_data[i].getContent() != CONTENT_IGNORE)
 380                                         continue;
 381
 382                                 float f = 0.55 + noise_factor->result[index2d];
 383                                 if (f < 0.01)
 384                                         f = 0.01;
 385                                 else if (f >= 1.0)
 386                                         f *= 1.6;
 387                                 float h = noise_height->result[index2d];
 388
 389                                 if (noise_ground->result[index] * f < y - h) {
 390                                         if (y <= water_level)
 391                                                 vm->m_data[i] = MapNode(c_water_source);
 392                                         else
 393                                                 vm->m_data[i] = MapNode(CONTENT_AIR);
 394                                 } else {
 395                                         vm->m_data[i] = MapNode(c_stone);
 396                                         if (y > stone_surface_max_y)
 397                                                 stone_surface_max_y = y;
 398                                 }
 399                         }
 400                         index2d -= ystride;
 401                 }
 402                 index2d += ystride;
 403         }
 404
 405         return stone_surface_max_y;
 406 }
 407
 408
 409 MgStoneType MapgenV5::generateBiomes(float *heat_map, float *humidity_map)
 410 {
 411         v3s16 em = vm->m_area.getExtent();
 412         u32 index = 0;
 413         MgStoneType stone_type = STONE;
 414
 415         for (s16 z = node_min.Z; z <= node_max.Z; z++)
 416         for (s16 x = node_min.X; x <= node_max.X; x++, index++) {
 417                 Biome *biome = NULL;
 418                 u16 depth_top = 0;
 419                 u16 base_filler = 0;
 420                 u16 depth_water_top = 0;
 421                 u32 vi = vm->m_area.index(x, node_max.Y, z);
 422
 423                 // Check node at base of mapchunk above, either a node of a previously
 424                 // generated mapchunk or if not, a node of overgenerated base terrain.
 425                 content_t c_above = vm->m_data[vi + em.X].getContent();
 426                 bool air_above = c_above == CONTENT_AIR;
 427                 bool water_above = c_above == c_water_source;
 428
 429                 // If there is air or water above enable top/filler placement, otherwise force
 430                 // nplaced to stone level by setting a number exceeding any possible filler depth.
 431                 u16 nplaced = (air_above || water_above) ? 0 : (u16)-1;
 432
 433                 for (s16 y = node_max.Y; y >= node_min.Y; y--) {
 434                         content_t c = vm->m_data[vi].getContent();
 435
 436                         // Biome is recalculated each time an upper surface is detected while
 437                         // working down a column. The selected biome then remains in effect for
 438                         // all nodes below until the next surface and biome recalculation.
 439                         // Biome is recalculated:
 440                         // 1. At the surface of stone below air or water.
 441                         // 2. At the surface of water below air.
 442                         // 3. When stone or water is detected but biome has not yet been calculated.
 443                         if ((c == c_stone && (air_above || water_above || !biome)) ||
 444                                         (c == c_water_source && (air_above || !biome))) {
 445                                 biome = bmgr->getBiome(heat_map[index], humidity_map[index], y);
 446                                 depth_top = biome->depth_top;
 447                                 base_filler = MYMAX(depth_top + biome->depth_filler
 448                                                 + noise_filler_depth->result[index], 0);
 449                                 depth_water_top = biome->depth_water_top;
 450
 451                                 // Detect stone type for dungeons during every biome calculation.
 452                                 // This is more efficient than detecting per-node and will not
 453                                 // miss any desert stone or sandstone biomes.
 454                                 if (biome->c_stone == c_desert_stone)
 455                                         stone_type = DESERT_STONE;
 456                                 else if (biome->c_stone == c_sandstone)
 457                                         stone_type = SANDSTONE;
 458                         }
 459
 460                         if (c == c_stone) {
 461                                 content_t c_below = vm->m_data[vi - em.X].getContent();
 462
 463                                 // If the node below isn't solid, make this node stone, so that
 464                                 // any top/filler nodes above are structurally supported.
 465                                 // This is done by aborting the cycle of top/filler placement
 466                                 // immediately by forcing nplaced to stone level.
 467                                 if (c_below == CONTENT_AIR || c_below == c_water_source)
 468                                         nplaced = (u16)-1;
 469
 470                                 if (nplaced < depth_top) {
 471                                         vm->m_data[vi] = MapNode(biome->c_top);
 472                                         nplaced++;
 473                                 } else if (nplaced < base_filler) {
 474                                         vm->m_data[vi] = MapNode(biome->c_filler);
 475                                         nplaced++;
 476                                 } else {
 477                                         vm->m_data[vi] = MapNode(biome->c_stone);
 478                                 }
 479
 480                                 air_above = false;
 481                                 water_above = false;
 482                         } else if (c == c_water_source) {
 483                                 vm->m_data[vi] = MapNode((y > (s32)(water_level - depth_water_top)) ?
 484                                                 biome->c_water_top : biome->c_water);
 485                                 nplaced = 0;  // Enable top/filler placement for next surface
 486                                 air_above = false;
 487                                 water_above = true;
 488                         } else if (c == CONTENT_AIR) {
 489                                 nplaced = 0;  // Enable top/filler placement for next surface
 490                                 air_above = true;
 491                                 water_above = false;
 492                         } else {  // Possible various nodes overgenerated from neighbouring mapchunks
 493                                 nplaced = (u16)-1;  // Disable top/filler placement
 494                                 air_above = false;
 495                                 water_above = false;
 496                         }
 497
 498                         vm->m_area.add_y(em, vi, -1);
 499                 }
 500         }
 501
 502         return stone_type;
 503 }
 504
 505
 506 void MapgenV5::generateCaves(int max_stone_y)
 507 {
 508         if (max_stone_y >= node_min.Y) {
 509                 u32 index = 0;
 510
 511                 for (s16 z = node_min.Z; z <= node_max.Z; z++)
 512                 for (s16 y = node_min.Y - 1; y <= node_max.Y + 1; y++) {
 513                         u32 i = vm->m_area.index(node_min.X, y, z);
 514                         for (s16 x = node_min.X; x <= node_max.X; x++, i++, index++) {
 515                                 float d1 = contour(noise_cave1->result[index]);
 516                                 float d2 = contour(noise_cave2->result[index]);
 517                                 if (d1*d2 > 0.125) {
 518                                         content_t c = vm->m_data[i].getContent();
 519                                         if (!ndef->get(c).is_ground_content || c == CONTENT_AIR)
 520                                                 continue;
 521
 522                                         vm->m_data[i] = MapNode(CONTENT_AIR);
 523                                 }
 524                         }
 525                 }
 526         }
 527
 528         if (node_max.Y > LARGE_CAVE_DEPTH)
 529                 return;
 530
 531         PseudoRandom ps(blockseed + 21343);
 532         u32 bruises_count = (ps.range(1, 4) == 1) ? ps.range(1, 2) : 0;
 533         for (u32 i = 0; i < bruises_count; i++) {
 534                 CaveV5 cave(this, &ps);
 535                 cave.makeCave(node_min, node_max, max_stone_y);
 536         }
 537 }
 538
 539
 540 void MapgenV5::dustTopNodes()
 541 {
 542         if (node_max.Y < water_level)
 543                 return;
 544
 545         v3s16 em = vm->m_area.getExtent();
 546         u32 index = 0;
 547
 548         for (s16 z = node_min.Z; z <= node_max.Z; z++)
 549         for (s16 x = node_min.X; x <= node_max.X; x++, index++) {
 550                 Biome *biome = (Biome *)bmgr->getRaw(biomemap[index]);
 551
 552                 if (biome->c_dust == CONTENT_IGNORE)
 553                         continue;
 554
 555                 u32 vi = vm->m_area.index(x, full_node_max.Y, z);
 556                 content_t c_full_max = vm->m_data[vi].getContent();
 557                 s16 y_start;
 558
 559                 if (c_full_max == CONTENT_AIR) {
 560                         y_start = full_node_max.Y - 1;
 561                 } else if (c_full_max == CONTENT_IGNORE) {
 562                         vi = vm->m_area.index(x, node_max.Y + 1, z);
 563                         content_t c_max = vm->m_data[vi].getContent();
 564
 565                         if (c_max == CONTENT_AIR)
 566                                 y_start = node_max.Y;
 567                         else
 568                                 continue;
 569                 } else {
 570                         continue;
 571                 }
 572
 573                 vi = vm->m_area.index(x, y_start, z);
 574                 for (s16 y = y_start; y >= node_min.Y - 1; y--) {
 575                         if (vm->m_data[vi].getContent() != CONTENT_AIR)
 576                                 break;
 577
 578                         vm->m_area.add_y(em, vi, -1);
 579                 }
 580
 581                 content_t c = vm->m_data[vi].getContent();
 582                 if (!ndef->get(c).buildable_to && c != CONTENT_IGNORE && c != biome->c_dust) {
 583                         vm->m_area.add_y(em, vi, 1);
 584                         vm->m_data[vi] = MapNode(biome->c_dust);
 585                 }
 586         }
 587 }
 588