src/mapgen_fractal.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_fractal.h"
  41
  42
  43 FlagDesc flagdesc_mapgen_fractal[] = {
  44         {"julia", MGFRACTAL_JULIA},
  45         {NULL,    0}
  46 };
  47
  48 ///////////////////////////////////////////////////////////////////////////////////////
  49
  50
  51 MapgenFractal::MapgenFractal(int mapgenid, MapgenParams *params, EmergeManager *emerge)
  52         : Mapgen(mapgenid, params, emerge)
  53 {
  54         this->m_emerge = emerge;
  55         this->bmgr     = emerge->biomemgr;
  56
  57         //// amount of elements to skip for the next index
  58         //// for noise/height/biome maps (not vmanip)
  59         this->ystride = csize.X;
  60         this->zstride = csize.X * (csize.Y + 2);
  61
  62         this->biomemap        = new u8[csize.X * csize.Z];
  63         this->heightmap       = new s16[csize.X * csize.Z];
  64         this->heatmap         = NULL;
  65         this->humidmap        = NULL;
  66
  67         MapgenFractalParams *sp = (MapgenFractalParams *)params->sparams;
  68         this->spflags = sp->spflags;
  69
  70         this->iterations = sp->iterations;
  71         this->scale = sp->scale;
  72
  73         this->moffset = sp->moffset;
  74         this->mslice_w = sp->mslice_w;
  75
  76         this->joffset = sp->joffset;
  77         this->jslice_w = sp->jslice_w;
  78         this->julia_x = sp->julia_x;
  79         this->julia_y = sp->julia_y;
  80         this->julia_z = sp->julia_z;
  81         this->julia_w = sp->julia_w;
  82
  83         //// 2D terrain noise
  84         noise_seabed = new Noise(&sp->np_seabed, seed, csize.X, csize.Z);
  85
  86         //// 3D terrain noise
  87         noise_cave1 = new Noise(&sp->np_cave1, seed, csize.X, csize.Y + 2, csize.Z);
  88         noise_cave2 = new Noise(&sp->np_cave2, seed, csize.X, csize.Y + 2, csize.Z);
  89
  90         //// Biome noise
  91         noise_heat           = new Noise(&params->np_biome_heat,           seed, csize.X, csize.Z);
  92         noise_humidity       = new Noise(&params->np_biome_humidity,       seed, csize.X, csize.Z);
  93         noise_heat_blend     = new Noise(&params->np_biome_heat_blend,     seed, csize.X, csize.Z);
  94         noise_humidity_blend = new Noise(&params->np_biome_humidity_blend, seed, csize.X, csize.Z);
  95
  96         //// Resolve nodes to be used
  97         INodeDefManager *ndef = emerge->ndef;
  98
  99         c_stone                = ndef->getId("mapgen_stone");
 100         c_water_source         = ndef->getId("mapgen_water_source");
 101         c_lava_source          = ndef->getId("mapgen_lava_source");
 102         c_desert_stone         = ndef->getId("mapgen_desert_stone");
 103         c_ice                  = ndef->getId("mapgen_ice");
 104         c_sandstone            = ndef->getId("mapgen_sandstone");
 105
 106         c_cobble               = ndef->getId("mapgen_cobble");
 107         c_stair_cobble         = ndef->getId("mapgen_stair_cobble");
 108         c_mossycobble          = ndef->getId("mapgen_mossycobble");
 109         c_sandstonebrick       = ndef->getId("mapgen_sandstonebrick");
 110         c_stair_sandstonebrick = ndef->getId("mapgen_stair_sandstonebrick");
 111
 112         if (c_ice == CONTENT_IGNORE)
 113                 c_ice = CONTENT_AIR;
 114         if (c_mossycobble == CONTENT_IGNORE)
 115                 c_mossycobble = c_cobble;
 116         if (c_stair_cobble == CONTENT_IGNORE)
 117                 c_stair_cobble = c_cobble;
 118         if (c_sandstonebrick == CONTENT_IGNORE)
 119                 c_sandstonebrick = c_sandstone;
 120         if (c_stair_sandstonebrick == CONTENT_IGNORE)
 121                 c_stair_sandstonebrick = c_sandstone;
 122 }
 123
 124
 125 MapgenFractal::~MapgenFractal()
 126 {
 127         delete noise_seabed;
 128
 129         delete noise_cave1;
 130         delete noise_cave2;
 131
 132         delete noise_heat;
 133         delete noise_humidity;
 134         delete noise_heat_blend;
 135         delete noise_humidity_blend;
 136
 137         delete[] heightmap;
 138         delete[] biomemap;
 139 }
 140
 141
 142 MapgenFractalParams::MapgenFractalParams()
 143 {
 144         spflags = 0;
 145
 146         iterations = 9;
 147         scale = v3f(1024.0, 256.0, 1024.0);
 148
 149         moffset = v3f(1.75, 0.0, 0.0);  // Mandelbrot set only
 150         mslice_w = 0.0;
 151
 152         joffset = v3f(0.0, 1.0, 0.0);  // Julia set only
 153         jslice_w = 0.0;
 154         julia_x = 0.33;
 155         julia_y = 0.33;
 156         julia_z = 0.33;
 157         julia_w = 0.33;
 158
 159         np_seabed = NoiseParams(-14, 9,  v3f(600, 600, 600), 41900, 5, 0.6, 2.0);
 160         np_cave1  = NoiseParams(0,   12, v3f(128, 128, 128), 52534, 4, 0.5, 2.0);
 161         np_cave2  = NoiseParams(0,   12, v3f(128, 128, 128), 10325, 4, 0.5, 2.0);
 162 }
 163
 164
 165 void MapgenFractalParams::readParams(const Settings *settings)
 166 {
 167         settings->getFlagStrNoEx("mgfractal_spflags", spflags, flagdesc_mapgen_fractal);
 168
 169         settings->getU16NoEx("mgfractal_iterations", iterations);
 170         settings->getV3FNoEx("mgfractal_scale", scale);
 171
 172         settings->getV3FNoEx("mgfractal_moffset", moffset);
 173         settings->getFloatNoEx("mgfractal_mslice_w", mslice_w);
 174
 175         settings->getV3FNoEx("mgfractal_joffset", joffset);
 176         settings->getFloatNoEx("mgfractal_jslice_w", jslice_w);
 177         settings->getFloatNoEx("mgfractal_julia_x", julia_x);
 178         settings->getFloatNoEx("mgfractal_julia_y", julia_y);
 179         settings->getFloatNoEx("mgfractal_julia_z", julia_z);
 180         settings->getFloatNoEx("mgfractal_julia_w", julia_w);
 181
 182         settings->getNoiseParams("mgfractal_np_seabed", np_seabed);
 183         settings->getNoiseParams("mgfractal_np_cave1", np_cave1);
 184         settings->getNoiseParams("mgfractal_np_cave2", np_cave2);
 185 }
 186
 187
 188 void MapgenFractalParams::writeParams(Settings *settings) const
 189 {
 190         settings->setFlagStr("mgfractal_spflags", spflags, flagdesc_mapgen_fractal, U32_MAX);
 191
 192         settings->setU16("mgfractal_iterations", iterations);
 193         settings->setV3F("mgfractal_scale", scale);
 194
 195         settings->setV3F("mgfractal_moffset", moffset);
 196         settings->setFloat("mgfractal_mslice_w", mslice_w);
 197
 198         settings->setV3F("mgfractal_joffset", joffset);
 199         settings->setFloat("mgfractal_jslice_w", jslice_w);
 200         settings->setFloat("mgfractal_julia_x", julia_x);
 201         settings->setFloat("mgfractal_julia_y", julia_y);
 202         settings->setFloat("mgfractal_julia_z", julia_z);
 203         settings->setFloat("mgfractal_julia_w", julia_w);
 204
 205         settings->setNoiseParams("mgfractal_np_seabed", np_seabed);
 206         settings->setNoiseParams("mgfractal_np_cave1", np_cave1);
 207         settings->setNoiseParams("mgfractal_np_cave2", np_cave2);
 208 }
 209
 210
 211 /////////////////////////////////////////////////////////////////
 212
 213
 214 int MapgenFractal::getGroundLevelAtPoint(v2s16 p)
 215 {
 216         s16 search_start = 128;
 217         s16 search_end = -128;
 218
 219         for (s16 y = search_start; y >= search_end; y--) {
 220                 if (getFractalAtPoint(p.X, y, p.Y))
 221                         return y;
 222         }
 223
 224         return -MAX_MAP_GENERATION_LIMIT;
 225 }
 226
 227
 228 void MapgenFractal::makeChunk(BlockMakeData *data)
 229 {
 230         // Pre-conditions
 231         assert(data->vmanip);
 232         assert(data->nodedef);
 233         assert(data->blockpos_requested.X >= data->blockpos_min.X &&
 234                 data->blockpos_requested.Y >= data->blockpos_min.Y &&
 235                 data->blockpos_requested.Z >= data->blockpos_min.Z);
 236         assert(data->blockpos_requested.X <= data->blockpos_max.X &&
 237                 data->blockpos_requested.Y <= data->blockpos_max.Y &&
 238                 data->blockpos_requested.Z <= data->blockpos_max.Z);
 239
 240         this->generating = true;
 241         this->vm   = data->vmanip;
 242         this->ndef = data->nodedef;
 243         //TimeTaker t("makeChunk");
 244
 245         v3s16 blockpos_min = data->blockpos_min;
 246         v3s16 blockpos_max = data->blockpos_max;
 247         node_min = blockpos_min * MAP_BLOCKSIZE;
 248         node_max = (blockpos_max + v3s16(1, 1, 1)) * MAP_BLOCKSIZE - v3s16(1, 1, 1);
 249         full_node_min = (blockpos_min - 1) * MAP_BLOCKSIZE;
 250         full_node_max = (blockpos_max + 2) * MAP_BLOCKSIZE - v3s16(1, 1, 1);
 251
 252         blockseed = getBlockSeed2(full_node_min, seed);
 253
 254         // Make some noise
 255         calculateNoise();
 256
 257         // Generate base terrain, mountains, and ridges with initial heightmaps
 258         s16 stone_surface_max_y = generateTerrain();
 259
 260         // Create heightmap
 261         updateHeightmap(node_min, node_max);
 262
 263         // Create biomemap at heightmap surface
 264         bmgr->calcBiomes(csize.X, csize.Z, noise_heat->result,
 265                 noise_humidity->result, heightmap, biomemap);
 266
 267         // Actually place the biome-specific nodes
 268         MgStoneType stone_type = generateBiomes(noise_heat->result, noise_humidity->result);
 269
 270         if (flags & MG_CAVES)
 271                 generateCaves(stone_surface_max_y);
 272
 273         if ((flags & MG_DUNGEONS) && (stone_surface_max_y >= node_min.Y)) {
 274                 DungeonParams dp;
 275
 276                 dp.np_rarity  = nparams_dungeon_rarity;
 277                 dp.np_density = nparams_dungeon_density;
 278                 dp.np_wetness = nparams_dungeon_wetness;
 279                 dp.c_water    = c_water_source;
 280                 if (stone_type == STONE) {
 281                         dp.c_cobble = c_cobble;
 282                         dp.c_moss   = c_mossycobble;
 283                         dp.c_stair  = c_stair_cobble;
 284
 285                         dp.diagonal_dirs = false;
 286                         dp.mossratio     = 3.0;
 287                         dp.holesize      = v3s16(1, 2, 1);
 288                         dp.roomsize      = v3s16(0, 0, 0);
 289                         dp.notifytype    = GENNOTIFY_DUNGEON;
 290                 } else if (stone_type == DESERT_STONE) {
 291                         dp.c_cobble = c_desert_stone;
 292                         dp.c_moss   = c_desert_stone;
 293                         dp.c_stair  = c_desert_stone;
 294
 295                         dp.diagonal_dirs = true;
 296                         dp.mossratio     = 0.0;
 297                         dp.holesize      = v3s16(2, 3, 2);
 298                         dp.roomsize      = v3s16(2, 5, 2);
 299                         dp.notifytype    = GENNOTIFY_TEMPLE;
 300                 } else if (stone_type == SANDSTONE) {
 301                         dp.c_cobble = c_sandstonebrick;
 302                         dp.c_moss   = c_sandstonebrick;
 303                         dp.c_stair  = c_sandstonebrick;
 304
 305                         dp.diagonal_dirs = false;
 306                         dp.mossratio     = 0.0;
 307                         dp.holesize      = v3s16(2, 2, 2);
 308                         dp.roomsize      = v3s16(2, 0, 2);
 309                         dp.notifytype    = GENNOTIFY_DUNGEON;
 310                 }
 311
 312                 DungeonGen dgen(this, &dp);
 313                 dgen.generate(blockseed, full_node_min, full_node_max);
 314         }
 315
 316         // Generate the registered decorations
 317         m_emerge->decomgr->placeAllDecos(this, blockseed, node_min, node_max);
 318
 319         // Generate the registered ores
 320         m_emerge->oremgr->placeAllOres(this, blockseed, node_min, node_max);
 321
 322         // Sprinkle some dust on top after everything else was generated
 323         dustTopNodes();
 324
 325         //printf("makeChunk: %dms\n", t.stop());
 326
 327         updateLiquid(&data->transforming_liquid, full_node_min, full_node_max);
 328
 329         if (flags & MG_LIGHT)
 330                 calcLighting(node_min - v3s16(0, 1, 0), node_max + v3s16(0, 1, 0),
 331                         full_node_min, full_node_max);
 332
 333         //setLighting(node_min - v3s16(1, 0, 1) * MAP_BLOCKSIZE,
 334         //                      node_max + v3s16(1, 0, 1) * MAP_BLOCKSIZE, 0xFF);
 335
 336         this->generating = false;
 337 }
 338
 339
 340 void MapgenFractal::calculateNoise()
 341 {
 342         //TimeTaker t("calculateNoise", NULL, PRECISION_MICRO);
 343         int x = node_min.X;
 344         int y = node_min.Y - 1;
 345         int z = node_min.Z;
 346
 347         noise_seabed->perlinMap2D(x, z);
 348
 349         if (flags & MG_CAVES) {
 350                 noise_cave1->perlinMap3D(x, y, z);
 351                 noise_cave2->perlinMap3D(x, y, z);
 352         }
 353
 354         noise_heat->perlinMap2D(x, z);
 355         noise_humidity->perlinMap2D(x, z);
 356         noise_heat_blend->perlinMap2D(x, z);
 357         noise_humidity_blend->perlinMap2D(x, z);
 358
 359         for (s32 i = 0; i < csize.X * csize.Z; i++) {
 360                 noise_heat->result[i] += noise_heat_blend->result[i];
 361                 noise_humidity->result[i] += noise_humidity_blend->result[i];
 362         }
 363
 364         heatmap = noise_heat->result;
 365         humidmap = noise_humidity->result;
 366         //printf("calculateNoise: %dus\n", t.stop());
 367 }
 368
 369
 370 bool MapgenFractal::getFractalAtPoint(s16 x, s16 y, s16 z)
 371 {
 372         float cx, cy, cz, cw, ox, oy, oz, ow;
 373
 374         if (spflags & MGFRACTAL_JULIA) {  // Julia set
 375                 cx = julia_x;
 376                 cy = julia_y;
 377                 cz = julia_z;
 378                 cw = julia_w;
 379                 ox = (float)x / scale.X - joffset.X;
 380                 oy = (float)y / scale.Y - joffset.Y;
 381                 oz = (float)z / scale.Z - joffset.Z;
 382                 ow = jslice_w;
 383         } else {  // Mandelbrot set
 384                 cx = (float)x / scale.X - moffset.X;
 385                 cy = (float)y / scale.Y - moffset.Y;
 386                 cz = (float)z / scale.Z - moffset.Z;
 387                 cw = mslice_w;
 388                 ox = 0.0f;
 389                 oy = 0.0f;
 390                 oz = 0.0f;
 391                 ow = 0.0f;
 392         }
 393
 394         for (u16 iter = 0; iter < iterations; iter++) {
 395                 // 4D "Roundy" Mandelbrot set
 396                 float nx = ox * ox - oy * oy - oz * oz - ow * ow + cx;
 397                 float ny = 2.0f * (ox * oy + oz * ow) + cy;
 398                 float nz = 2.0f * (ox * oz + oy * ow) + cz;
 399                 float nw = 2.0f * (ox * ow + oy * oz) + cw;
 400
 401                 if (nx * nx + ny * ny + nz * nz + nw * nw > 4.0f)
 402                         return false;
 403
 404                 ox = nx;
 405                 oy = ny;
 406                 oz = nz;
 407                 ow = nw;
 408         }
 409
 410         return true;
 411 }
 412
 413
 414 s16 MapgenFractal::generateTerrain()
 415 {
 416         MapNode n_air(CONTENT_AIR);
 417         MapNode n_stone(c_stone);
 418         MapNode n_water(c_water_source);
 419
 420         s16 stone_surface_max_y = -MAX_MAP_GENERATION_LIMIT;
 421         u32 index2d = 0;
 422
 423         for (s16 z = node_min.Z; z <= node_max.Z; z++) {
 424                 for (s16 y = node_min.Y - 1; y <= node_max.Y + 1; y++) {
 425                         u32 vi = vm->m_area.index(node_min.X, y, z);
 426                         for (s16 x = node_min.X; x <= node_max.X; x++, vi++, index2d++) {
 427                                 if (vm->m_data[vi].getContent() == CONTENT_IGNORE) {
 428                                         s16 seabed_height = noise_seabed->result[index2d];
 429
 430                                         if (y <= seabed_height || getFractalAtPoint(x, y, z)) {
 431                                                 vm->m_data[vi] = n_stone;
 432                                                 if (y > stone_surface_max_y)
 433                                                         stone_surface_max_y = y;
 434                                         } else if (y <= water_level) {
 435                                                 vm->m_data[vi] = n_water;
 436                                         } else {
 437                                                 vm->m_data[vi] = n_air;
 438                                         }
 439                                 }
 440                         }
 441                         index2d -= ystride;
 442                 }
 443                 index2d += ystride;
 444         }
 445
 446         return stone_surface_max_y;
 447 }
 448
 449
 450 MgStoneType MapgenFractal::generateBiomes(float *heat_map, float *humidity_map)
 451 {
 452         v3s16 em = vm->m_area.getExtent();
 453         u32 index = 0;
 454         MgStoneType stone_type = STONE;
 455
 456         for (s16 z = node_min.Z; z <= node_max.Z; z++)
 457         for (s16 x = node_min.X; x <= node_max.X; x++, index++) {
 458                 Biome *biome = NULL;
 459                 u16 depth_top = 0;
 460                 u16 base_filler = 0;
 461                 u16 depth_water_top = 0;
 462                 u32 vi = vm->m_area.index(x, node_max.Y, z);
 463
 464                 // Check node at base of mapchunk above, either a node of a previously
 465                 // generated mapchunk or if not, a node of overgenerated base terrain.
 466                 content_t c_above = vm->m_data[vi + em.X].getContent();
 467                 bool air_above = c_above == CONTENT_AIR;
 468                 bool water_above = c_above == c_water_source;
 469
 470                 // If there is air or water above enable top/filler placement, otherwise force
 471                 // nplaced to stone level by setting a number exceeding any possible filler depth.
 472                 u16 nplaced = (air_above || water_above) ? 0 : U16_MAX;
 473
 474
 475                 for (s16 y = node_max.Y; y >= node_min.Y; y--) {
 476                         content_t c = vm->m_data[vi].getContent();
 477
 478                         // Biome is recalculated each time an upper surface is detected while
 479                         // working down a column. The selected biome then remains in effect for
 480                         // all nodes below until the next surface and biome recalculation.
 481                         // Biome is recalculated:
 482                         // 1. At the surface of stone below air or water.
 483                         // 2. At the surface of water below air.
 484                         // 3. When stone or water is detected but biome has not yet been calculated.
 485                         if ((c == c_stone && (air_above || water_above || !biome)) ||
 486                                         (c == c_water_source && (air_above || !biome))) {
 487                                 biome = bmgr->getBiome(heat_map[index], humidity_map[index], y);
 488                                 depth_top = biome->depth_top;
 489                                 base_filler = depth_top + biome->depth_filler;
 490                                 depth_water_top = biome->depth_water_top;
 491
 492                                 // Detect stone type for dungeons during every biome calculation.
 493                                 // This is more efficient than detecting per-node and will not
 494                                 // miss any desert stone or sandstone biomes.
 495                                 if (biome->c_stone == c_desert_stone)
 496                                         stone_type = DESERT_STONE;
 497                                 else if (biome->c_stone == c_sandstone)
 498                                         stone_type = SANDSTONE;
 499                         }
 500
 501                         if (c == c_stone) {
 502                                 content_t c_below = vm->m_data[vi - em.X].getContent();
 503
 504                                 // If the node below isn't solid, make this node stone, so that
 505                                 // any top/filler nodes above are structurally supported.
 506                                 // This is done by aborting the cycle of top/filler placement
 507                                 // immediately by forcing nplaced to stone level.
 508                                 if (c_below == CONTENT_AIR || c_below == c_water_source)
 509                                         nplaced = U16_MAX;
 510
 511                                 if (nplaced < depth_top) {
 512                                         vm->m_data[vi] = MapNode(biome->c_top);
 513                                         nplaced++;
 514                                 } else if (nplaced < base_filler) {
 515                                         vm->m_data[vi] = MapNode(biome->c_filler);
 516                                         nplaced++;
 517                                 } else {
 518                                         vm->m_data[vi] = MapNode(biome->c_stone);
 519                                 }
 520
 521                                 air_above = false;
 522                                 water_above = false;
 523                         } else if (c == c_water_source) {
 524                                 vm->m_data[vi] = MapNode((y > (s32)(water_level - depth_water_top)) ?
 525                                                 biome->c_water_top : biome->c_water);
 526                                 nplaced = 0;  // Enable top/filler placement for next surface
 527                                 air_above = false;
 528                                 water_above = true;
 529                         } else if (c == CONTENT_AIR) {
 530                                 nplaced = 0;  // Enable top/filler placement for next surface
 531                                 air_above = true;
 532                                 water_above = false;
 533                         } else {  // Possible various nodes overgenerated from neighbouring mapchunks
 534                                 nplaced = U16_MAX;  // Disable top/filler placement
 535                                 air_above = false;
 536                                 water_above = false;
 537                         }
 538
 539                         vm->m_area.add_y(em, vi, -1);
 540                 }
 541         }
 542
 543         return stone_type;
 544 }
 545
 546
 547 void MapgenFractal::dustTopNodes()
 548 {
 549         if (node_max.Y < water_level)
 550                 return;
 551
 552         v3s16 em = vm->m_area.getExtent();
 553         u32 index = 0;
 554
 555         for (s16 z = node_min.Z; z <= node_max.Z; z++)
 556         for (s16 x = node_min.X; x <= node_max.X; x++, index++) {
 557                 Biome *biome = (Biome *)bmgr->getRaw(biomemap[index]);
 558
 559                 if (biome->c_dust == CONTENT_IGNORE)
 560                         continue;
 561
 562                 u32 vi = vm->m_area.index(x, full_node_max.Y, z);
 563                 content_t c_full_max = vm->m_data[vi].getContent();
 564                 s16 y_start;
 565
 566                 if (c_full_max == CONTENT_AIR) {
 567                         y_start = full_node_max.Y - 1;
 568                 } else if (c_full_max == CONTENT_IGNORE) {
 569                         vi = vm->m_area.index(x, node_max.Y + 1, z);
 570                         content_t c_max = vm->m_data[vi].getContent();
 571
 572                         if (c_max == CONTENT_AIR)
 573                                 y_start = node_max.Y;
 574                         else
 575                                 continue;
 576                 } else {
 577                         continue;
 578                 }
 579
 580                 vi = vm->m_area.index(x, y_start, z);
 581                 for (s16 y = y_start; y >= node_min.Y - 1; y--) {
 582                         if (vm->m_data[vi].getContent() != CONTENT_AIR)
 583                                 break;
 584
 585                         vm->m_area.add_y(em, vi, -1);
 586                 }
 587
 588                 content_t c = vm->m_data[vi].getContent();
 589                 if (!ndef->get(c).buildable_to && c != CONTENT_IGNORE && c != biome->c_dust) {
 590                         vm->m_area.add_y(em, vi, 1);
 591                         vm->m_data[vi] = MapNode(biome->c_dust);
 592                 }
 593         }
 594 }
 595
 596
 597 void MapgenFractal::generateCaves(s16 max_stone_y)
 598 {
 599         if (max_stone_y >= node_min.Y) {
 600                 u32 index = 0;
 601
 602                 for (s16 z = node_min.Z; z <= node_max.Z; z++)
 603                 for (s16 y = node_min.Y - 1; y <= node_max.Y + 1; y++) {
 604                         u32 vi = vm->m_area.index(node_min.X, y, z);
 605                         for (s16 x = node_min.X; x <= node_max.X; x++, vi++, index++) {
 606                                 float d1 = contour(noise_cave1->result[index]);
 607                                 float d2 = contour(noise_cave2->result[index]);
 608                                 if (d1 * d2 > 0.4f) {
 609                                         content_t c = vm->m_data[vi].getContent();
 610                                         if (!ndef->get(c).is_ground_content || c == CONTENT_AIR)
 611                                                 continue;
 612
 613                                         vm->m_data[vi] = MapNode(CONTENT_AIR);
 614                                 }
 615                         }
 616                 }
 617         }
 618
 619         if (node_max.Y > MGFRACTAL_LARGE_CAVE_DEPTH)
 620                 return;
 621
 622         PseudoRandom ps(blockseed + 21343);
 623         u32 bruises_count = (ps.range(1, 4) == 1) ? ps.range(1, 2) : 0;
 624         for (u32 i = 0; i < bruises_count; i++) {
 625                 CaveFractal cave(this, &ps);
 626                 cave.makeCave(node_min, node_max, max_stone_y);
 627         }
 628 }