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->formula = sp->formula;
  71
  72         this->m_iterations = sp->m_iterations;
  73         this->m_scale = sp->m_scale;
  74         this->m_offset = sp->m_offset;
  75         this->m_slice_w = sp->m_slice_w;
  76
  77         this->j_iterations = sp->j_iterations;
  78         this->j_scale = sp->j_scale;
  79         this->j_offset = sp->j_offset;
  80         this->j_slice_w = sp->j_slice_w;
  81         this->julia_x = sp->julia_x;
  82         this->julia_y = sp->julia_y;
  83         this->julia_z = sp->julia_z;
  84         this->julia_w = sp->julia_w;
  85
  86         //// 2D terrain noise
  87         noise_seabed       = new Noise(&sp->np_seabed, seed, csize.X, csize.Z);
  88         noise_filler_depth = new Noise(&sp->np_filler_depth, seed, csize.X, csize.Z);
  89
  90         //// 3D terrain noise
  91         noise_cave1 = new Noise(&sp->np_cave1, seed, csize.X, csize.Y + 2, csize.Z);
  92         noise_cave2 = new Noise(&sp->np_cave2, seed, csize.X, csize.Y + 2, csize.Z);
  93
  94         //// Biome noise
  95         noise_heat           = new Noise(&params->np_biome_heat,           seed, csize.X, csize.Z);
  96         noise_humidity       = new Noise(&params->np_biome_humidity,       seed, csize.X, csize.Z);
  97         noise_heat_blend     = new Noise(&params->np_biome_heat_blend,     seed, csize.X, csize.Z);
  98         noise_humidity_blend = new Noise(&params->np_biome_humidity_blend, seed, csize.X, csize.Z);
  99
 100         //// Resolve nodes to be used
 101         INodeDefManager *ndef = emerge->ndef;
 102
 103         c_stone                = ndef->getId("mapgen_stone");
 104         c_water_source         = ndef->getId("mapgen_water_source");
 105         c_lava_source          = ndef->getId("mapgen_lava_source");
 106         c_desert_stone         = ndef->getId("mapgen_desert_stone");
 107         c_ice                  = ndef->getId("mapgen_ice");
 108         c_sandstone            = ndef->getId("mapgen_sandstone");
 109
 110         c_cobble               = ndef->getId("mapgen_cobble");
 111         c_stair_cobble         = ndef->getId("mapgen_stair_cobble");
 112         c_mossycobble          = ndef->getId("mapgen_mossycobble");
 113         c_sandstonebrick       = ndef->getId("mapgen_sandstonebrick");
 114         c_stair_sandstonebrick = ndef->getId("mapgen_stair_sandstonebrick");
 115
 116         if (c_ice == CONTENT_IGNORE)
 117                 c_ice = CONTENT_AIR;
 118         if (c_mossycobble == CONTENT_IGNORE)
 119                 c_mossycobble = c_cobble;
 120         if (c_stair_cobble == CONTENT_IGNORE)
 121                 c_stair_cobble = c_cobble;
 122         if (c_sandstonebrick == CONTENT_IGNORE)
 123                 c_sandstonebrick = c_sandstone;
 124         if (c_stair_sandstonebrick == CONTENT_IGNORE)
 125                 c_stair_sandstonebrick = c_sandstone;
 126 }
 127
 128
 129 MapgenFractal::~MapgenFractal()
 130 {
 131         delete noise_seabed;
 132         delete noise_filler_depth;
 133         delete noise_cave1;
 134         delete noise_cave2;
 135
 136         delete noise_heat;
 137         delete noise_humidity;
 138         delete noise_heat_blend;
 139         delete noise_humidity_blend;
 140
 141         delete[] heightmap;
 142         delete[] biomemap;
 143 }
 144
 145
 146 MapgenFractalParams::MapgenFractalParams()
 147 {
 148         spflags = 0;
 149
 150         formula = 1;
 151
 152         m_iterations = 9;  // Mandelbrot set only
 153         m_scale = v3f(1024.0, 256.0, 1024.0);
 154         m_offset = v3f(1.75, 0.0, 0.0);
 155         m_slice_w = 0.0;
 156
 157         j_iterations = 9;  // Julia set only
 158         j_scale = v3f(2048.0, 512.0, 2048.0);
 159         j_offset = v3f(0.0, 1.0, 0.0);
 160         j_slice_w = 0.0;
 161         julia_x = 0.33;
 162         julia_y = 0.33;
 163         julia_z = 0.33;
 164         julia_w = 0.33;
 165
 166         np_seabed       = NoiseParams(-14, 9,   v3f(600, 600, 600), 41900, 5, 0.6, 2.0);
 167         np_filler_depth = NoiseParams(0,   1.2, v3f(150, 150, 150), 261,   3, 0.7, 2.0);
 168         np_cave1        = NoiseParams(0,   12,  v3f(128, 128, 128), 52534, 4, 0.5, 2.0);
 169         np_cave2        = NoiseParams(0,   12,  v3f(128, 128, 128), 10325, 4, 0.5, 2.0);
 170 }
 171
 172
 173 void MapgenFractalParams::readParams(const Settings *settings)
 174 {
 175         settings->getFlagStrNoEx("mgfractal_spflags", spflags, flagdesc_mapgen_fractal);
 176
 177         settings->getU16NoEx("mgfractal_formula", formula);
 178
 179         settings->getU16NoEx("mgfractal_m_iterations", m_iterations);
 180         settings->getV3FNoEx("mgfractal_m_scale", m_scale);
 181         settings->getV3FNoEx("mgfractal_m_offset", m_offset);
 182         settings->getFloatNoEx("mgfractal_m_slice_w", m_slice_w);
 183
 184         settings->getU16NoEx("mgfractal_j_iterations", j_iterations);
 185         settings->getV3FNoEx("mgfractal_j_scale", j_scale);
 186         settings->getV3FNoEx("mgfractal_j_offset", j_offset);
 187         settings->getFloatNoEx("mgfractal_j_slice_w", j_slice_w);
 188         settings->getFloatNoEx("mgfractal_julia_x", julia_x);
 189         settings->getFloatNoEx("mgfractal_julia_y", julia_y);
 190         settings->getFloatNoEx("mgfractal_julia_z", julia_z);
 191         settings->getFloatNoEx("mgfractal_julia_w", julia_w);
 192
 193         settings->getNoiseParams("mgfractal_np_seabed", np_seabed);
 194         settings->getNoiseParams("mgfractal_np_filler_depth", np_filler_depth);
 195         settings->getNoiseParams("mgfractal_np_cave1", np_cave1);
 196         settings->getNoiseParams("mgfractal_np_cave2", np_cave2);
 197 }
 198
 199
 200 void MapgenFractalParams::writeParams(Settings *settings) const
 201 {
 202         settings->setFlagStr("mgfractal_spflags", spflags, flagdesc_mapgen_fractal, U32_MAX);
 203
 204         settings->setU16("mgfractal_formula", formula);
 205
 206         settings->setU16("mgfractal_m_iterations", m_iterations);
 207         settings->setV3F("mgfractal_m_scale", m_scale);
 208         settings->setV3F("mgfractal_m_offset", m_offset);
 209         settings->setFloat("mgfractal_m_slice_w", m_slice_w);
 210
 211         settings->setU16("mgfractal_j_iterations", j_iterations);
 212         settings->setV3F("mgfractal_j_scale", j_scale);
 213         settings->setV3F("mgfractal_j_offset", j_offset);
 214         settings->setFloat("mgfractal_j_slice_w", j_slice_w);
 215         settings->setFloat("mgfractal_julia_x", julia_x);
 216         settings->setFloat("mgfractal_julia_y", julia_y);
 217         settings->setFloat("mgfractal_julia_z", julia_z);
 218         settings->setFloat("mgfractal_julia_w", julia_w);
 219
 220         settings->setNoiseParams("mgfractal_np_seabed", np_seabed);
 221         settings->setNoiseParams("mgfractal_np_filler_depth", np_filler_depth);
 222         settings->setNoiseParams("mgfractal_np_cave1", np_cave1);
 223         settings->setNoiseParams("mgfractal_np_cave2", np_cave2);
 224 }
 225
 226
 227 /////////////////////////////////////////////////////////////////
 228
 229
 230 int MapgenFractal::getGroundLevelAtPoint(v2s16 p)
 231 {
 232         s16 search_start = 128;
 233         s16 search_end = -128;
 234
 235         for (s16 y = search_start; y >= search_end; y--) {
 236                 if (getFractalAtPoint(p.X, y, p.Y))
 237                         return y;
 238         }
 239
 240         return -MAX_MAP_GENERATION_LIMIT;
 241 }
 242
 243
 244 void MapgenFractal::makeChunk(BlockMakeData *data)
 245 {
 246         // Pre-conditions
 247         assert(data->vmanip);
 248         assert(data->nodedef);
 249         assert(data->blockpos_requested.X >= data->blockpos_min.X &&
 250                 data->blockpos_requested.Y >= data->blockpos_min.Y &&
 251                 data->blockpos_requested.Z >= data->blockpos_min.Z);
 252         assert(data->blockpos_requested.X <= data->blockpos_max.X &&
 253                 data->blockpos_requested.Y <= data->blockpos_max.Y &&
 254                 data->blockpos_requested.Z <= data->blockpos_max.Z);
 255
 256         this->generating = true;
 257         this->vm   = data->vmanip;
 258         this->ndef = data->nodedef;
 259         TimeTaker t("makeChunk");
 260
 261         v3s16 blockpos_min = data->blockpos_min;
 262         v3s16 blockpos_max = data->blockpos_max;
 263         node_min = blockpos_min * MAP_BLOCKSIZE;
 264         node_max = (blockpos_max + v3s16(1, 1, 1)) * MAP_BLOCKSIZE - v3s16(1, 1, 1);
 265         full_node_min = (blockpos_min - 1) * MAP_BLOCKSIZE;
 266         full_node_max = (blockpos_max + 2) * MAP_BLOCKSIZE - v3s16(1, 1, 1);
 267
 268         blockseed = getBlockSeed2(full_node_min, seed);
 269
 270         // Make some noise
 271         calculateNoise();
 272
 273         // Generate base terrain, mountains, and ridges with initial heightmaps
 274         s16 stone_surface_max_y = generateTerrain();
 275
 276         // Create heightmap
 277         updateHeightmap(node_min, node_max);
 278
 279         // Create biomemap at heightmap surface
 280         bmgr->calcBiomes(csize.X, csize.Z, noise_heat->result,
 281                 noise_humidity->result, heightmap, biomemap);
 282
 283         // Actually place the biome-specific nodes
 284         MgStoneType stone_type = generateBiomes(noise_heat->result, noise_humidity->result);
 285
 286         if (flags & MG_CAVES)
 287                 generateCaves(stone_surface_max_y);
 288
 289         if ((flags & MG_DUNGEONS) && (stone_surface_max_y >= node_min.Y)) {
 290                 DungeonParams dp;
 291
 292                 dp.np_rarity  = nparams_dungeon_rarity;
 293                 dp.np_density = nparams_dungeon_density;
 294                 dp.np_wetness = nparams_dungeon_wetness;
 295                 dp.c_water    = c_water_source;
 296                 if (stone_type == STONE) {
 297                         dp.c_cobble = c_cobble;
 298                         dp.c_moss   = c_mossycobble;
 299                         dp.c_stair  = c_stair_cobble;
 300
 301                         dp.diagonal_dirs = false;
 302                         dp.mossratio     = 3.0;
 303                         dp.holesize      = v3s16(1, 2, 1);
 304                         dp.roomsize      = v3s16(0, 0, 0);
 305                         dp.notifytype    = GENNOTIFY_DUNGEON;
 306                 } else if (stone_type == DESERT_STONE) {
 307                         dp.c_cobble = c_desert_stone;
 308                         dp.c_moss   = c_desert_stone;
 309                         dp.c_stair  = c_desert_stone;
 310
 311                         dp.diagonal_dirs = true;
 312                         dp.mossratio     = 0.0;
 313                         dp.holesize      = v3s16(2, 3, 2);
 314                         dp.roomsize      = v3s16(2, 5, 2);
 315                         dp.notifytype    = GENNOTIFY_TEMPLE;
 316                 } else if (stone_type == SANDSTONE) {
 317                         dp.c_cobble = c_sandstonebrick;
 318                         dp.c_moss   = c_sandstonebrick;
 319                         dp.c_stair  = c_sandstonebrick;
 320
 321                         dp.diagonal_dirs = false;
 322                         dp.mossratio     = 0.0;
 323                         dp.holesize      = v3s16(2, 2, 2);
 324                         dp.roomsize      = v3s16(2, 0, 2);
 325                         dp.notifytype    = GENNOTIFY_DUNGEON;
 326                 }
 327
 328                 DungeonGen dgen(this, &dp);
 329                 dgen.generate(blockseed, full_node_min, full_node_max);
 330         }
 331
 332         // Generate the registered decorations
 333         m_emerge->decomgr->placeAllDecos(this, blockseed, node_min, node_max);
 334
 335         // Generate the registered ores
 336         m_emerge->oremgr->placeAllOres(this, blockseed, node_min, node_max);
 337
 338         // Sprinkle some dust on top after everything else was generated
 339         dustTopNodes();
 340
 341         printf("makeChunk: %dms\n", t.stop());
 342
 343         updateLiquid(&data->transforming_liquid, full_node_min, full_node_max);
 344
 345         if (flags & MG_LIGHT)
 346                 calcLighting(node_min - v3s16(0, 1, 0), node_max + v3s16(0, 1, 0),
 347                         full_node_min, full_node_max);
 348
 349         //setLighting(node_min - v3s16(1, 0, 1) * MAP_BLOCKSIZE,
 350         //                      node_max + v3s16(1, 0, 1) * MAP_BLOCKSIZE, 0xFF);
 351
 352         this->generating = false;
 353 }
 354
 355
 356 void MapgenFractal::calculateNoise()
 357 {
 358         //TimeTaker t("calculateNoise", NULL, PRECISION_MICRO);
 359         int x = node_min.X;
 360         int y = node_min.Y - 1;
 361         int z = node_min.Z;
 362
 363         noise_seabed->perlinMap2D(x, z);
 364         noise_filler_depth->perlinMap2D(x, z);
 365
 366         if (flags & MG_CAVES) {
 367                 noise_cave1->perlinMap3D(x, y, z);
 368                 noise_cave2->perlinMap3D(x, y, z);
 369         }
 370
 371         noise_heat->perlinMap2D(x, z);
 372         noise_humidity->perlinMap2D(x, z);
 373         noise_heat_blend->perlinMap2D(x, z);
 374         noise_humidity_blend->perlinMap2D(x, z);
 375
 376         for (s32 i = 0; i < csize.X * csize.Z; i++) {
 377                 noise_heat->result[i] += noise_heat_blend->result[i];
 378                 noise_humidity->result[i] += noise_humidity_blend->result[i];
 379         }
 380
 381         heatmap = noise_heat->result;
 382         humidmap = noise_humidity->result;
 383         //printf("calculateNoise: %dus\n", t.stop());
 384 }
 385
 386
 387 bool MapgenFractal::getFractalAtPoint(s16 x, s16 y, s16 z)
 388 {
 389         float cx, cy, cz, cw, ox, oy, oz, ow;
 390
 391         if (spflags & MGFRACTAL_JULIA) {  // Julia set
 392                 cx = julia_x;
 393                 cy = julia_y;
 394                 cz = julia_z;
 395                 cw = julia_w;
 396                 ox = (float)x / j_scale.X - j_offset.X;
 397                 oy = (float)y / j_scale.Y - j_offset.Y;
 398                 oz = (float)z / j_scale.Z - j_offset.Z;
 399                 ow = j_slice_w;
 400         } else {  // Mandelbrot set
 401                 cx = (float)x / m_scale.X - m_offset.X;
 402                 cy = (float)y / m_scale.Y - m_offset.Y;
 403                 cz = (float)z / m_scale.Z - m_offset.Z;
 404                 cw = m_slice_w;
 405                 ox = 0.0f;
 406                 oy = 0.0f;
 407                 oz = 0.0f;
 408                 ow = 0.0f;
 409         }
 410
 411         u16 iterations = spflags & MGFRACTAL_JULIA ? j_iterations : m_iterations;
 412
 413         for (u16 iter = 0; iter < iterations; iter++) {
 414                 float nx = 0.0f;
 415                 float ny = 0.0f;
 416                 float nz = 0.0f;
 417                 float nw = 0.0f;
 418
 419                 if (formula == 1) {  // 4D "Roundy" Mandelbrot Set
 420                         nx = ox * ox - oy * oy - oz * oz - ow * ow + cx;
 421                         ny = 2.0f * (ox * oy + oz * ow) + cy;
 422                         nz = 2.0f * (ox * oz + oy * ow) + cz;
 423                         nw = 2.0f * (ox * ow + oy * oz) + cw;
 424                 } else if (formula == 2) {  // 4D "Squarry" Mandelbrot Set
 425                         nx = ox * ox - oy * oy - oz * oz - ow * ow + cx;
 426                         ny = 2.0f * (ox * oy + oz * ow) + cy;
 427                         nz = 2.0f * (ox * oz + oy * ow) + cz;
 428                         nw = 2.0f * (ox * ow - oy * oz) + cw;
 429                 } else if (formula == 3) {  // 4D "Mandy Cousin" Mandelbrot Set
 430                         nx = ox * ox - oy * oy - oz * oz + ow * ow + cx;
 431                         ny = 2.0f * (ox * oy + oz * ow) + cy;
 432                         nz = 2.0f * (ox * oz + oy * ow) + cz;
 433                         nw = 2.0f * (ox * ow + oy * oz) + cw;
 434                 } else if (formula == 4) {  // 4D Mandelbrot Set Variation
 435                         nx = ox * ox - oy * oy - oz * oz - ow * ow + cx;
 436                         ny = 2.0f * (ox * oy + oz * ow) + cy;
 437                         nz = 2.0f * (ox * oz - oy * ow) + cz;
 438                         nw = 2.0f * (ox * ow + oy * oz) + cw;
 439                 }
 440
 441                 if (nx * nx + ny * ny + nz * nz + nw * nw > 4.0f)
 442                         return false;
 443
 444                 ox = nx;
 445                 oy = ny;
 446                 oz = nz;
 447                 ow = nw;
 448         }
 449
 450         return true;
 451 }
 452
 453
 454 s16 MapgenFractal::generateTerrain()
 455 {
 456         MapNode n_air(CONTENT_AIR);
 457         MapNode n_stone(c_stone);
 458         MapNode n_water(c_water_source);
 459
 460         s16 stone_surface_max_y = -MAX_MAP_GENERATION_LIMIT;
 461         u32 index2d = 0;
 462
 463         for (s16 z = node_min.Z; z <= node_max.Z; z++) {
 464                 for (s16 y = node_min.Y - 1; y <= node_max.Y + 1; y++) {
 465                         u32 vi = vm->m_area.index(node_min.X, y, z);
 466                         for (s16 x = node_min.X; x <= node_max.X; x++, vi++, index2d++) {
 467                                 if (vm->m_data[vi].getContent() == CONTENT_IGNORE) {
 468                                         s16 seabed_height = noise_seabed->result[index2d];
 469
 470                                         if (y <= seabed_height || getFractalAtPoint(x, y, z)) {
 471                                                 vm->m_data[vi] = n_stone;
 472                                                 if (y > stone_surface_max_y)
 473                                                         stone_surface_max_y = y;
 474                                         } else if (y <= water_level) {
 475                                                 vm->m_data[vi] = n_water;
 476                                         } else {
 477                                                 vm->m_data[vi] = n_air;
 478                                         }
 479                                 }
 480                         }
 481                         index2d -= ystride;
 482                 }
 483                 index2d += ystride;
 484         }
 485
 486         return stone_surface_max_y;
 487 }
 488
 489
 490 MgStoneType MapgenFractal::generateBiomes(float *heat_map, float *humidity_map)
 491 {
 492         v3s16 em = vm->m_area.getExtent();
 493         u32 index = 0;
 494         MgStoneType stone_type = STONE;
 495
 496         for (s16 z = node_min.Z; z <= node_max.Z; z++)
 497         for (s16 x = node_min.X; x <= node_max.X; x++, index++) {
 498                 Biome *biome = NULL;
 499                 u16 depth_top = 0;
 500                 u16 base_filler = 0;
 501                 u16 depth_water_top = 0;
 502                 u32 vi = vm->m_area.index(x, node_max.Y, z);
 503
 504                 // Check node at base of mapchunk above, either a node of a previously
 505                 // generated mapchunk or if not, a node of overgenerated base terrain.
 506                 content_t c_above = vm->m_data[vi + em.X].getContent();
 507                 bool air_above = c_above == CONTENT_AIR;
 508                 bool water_above = c_above == c_water_source;
 509
 510                 // If there is air or water above enable top/filler placement, otherwise force
 511                 // nplaced to stone level by setting a number exceeding any possible filler depth.
 512                 u16 nplaced = (air_above || water_above) ? 0 : U16_MAX;
 513
 514
 515                 for (s16 y = node_max.Y; y >= node_min.Y; y--) {
 516                         content_t c = vm->m_data[vi].getContent();
 517
 518                         // Biome is recalculated each time an upper surface is detected while
 519                         // working down a column. The selected biome then remains in effect for
 520                         // all nodes below until the next surface and biome recalculation.
 521                         // Biome is recalculated:
 522                         // 1. At the surface of stone below air or water.
 523                         // 2. At the surface of water below air.
 524                         // 3. When stone or water is detected but biome has not yet been calculated.
 525                         if ((c == c_stone && (air_above || water_above || !biome)) ||
 526                                         (c == c_water_source && (air_above || !biome))) {
 527                                 biome = bmgr->getBiome(heat_map[index], humidity_map[index], y);
 528                                 depth_top = biome->depth_top;
 529                                 base_filler = MYMAX(depth_top + biome->depth_filler
 530                                         + noise_filler_depth->result[index], 0);
 531                                 depth_water_top = biome->depth_water_top;
 532
 533                                 // Detect stone type for dungeons during every biome calculation.
 534                                 // This is more efficient than detecting per-node and will not
 535                                 // miss any desert stone or sandstone biomes.
 536                                 if (biome->c_stone == c_desert_stone)
 537                                         stone_type = DESERT_STONE;
 538                                 else if (biome->c_stone == c_sandstone)
 539                                         stone_type = SANDSTONE;
 540                         }
 541
 542                         if (c == c_stone) {
 543                                 content_t c_below = vm->m_data[vi - em.X].getContent();
 544
 545                                 // If the node below isn't solid, make this node stone, so that
 546                                 // any top/filler nodes above are structurally supported.
 547                                 // This is done by aborting the cycle of top/filler placement
 548                                 // immediately by forcing nplaced to stone level.
 549                                 if (c_below == CONTENT_AIR || c_below == c_water_source)
 550                                         nplaced = U16_MAX;
 551
 552                                 if (nplaced < depth_top) {
 553                                         vm->m_data[vi] = MapNode(biome->c_top);
 554                                         nplaced++;
 555                                 } else if (nplaced < base_filler) {
 556                                         vm->m_data[vi] = MapNode(biome->c_filler);
 557                                         nplaced++;
 558                                 } else {
 559                                         vm->m_data[vi] = MapNode(biome->c_stone);
 560                                 }
 561
 562                                 air_above = false;
 563                                 water_above = false;
 564                         } else if (c == c_water_source) {
 565                                 vm->m_data[vi] = MapNode((y > (s32)(water_level - depth_water_top)) ?
 566                                                 biome->c_water_top : biome->c_water);
 567                                 nplaced = 0;  // Enable top/filler placement for next surface
 568                                 air_above = false;
 569                                 water_above = true;
 570                         } else if (c == CONTENT_AIR) {
 571                                 nplaced = 0;  // Enable top/filler placement for next surface
 572                                 air_above = true;
 573                                 water_above = false;
 574                         } else {  // Possible various nodes overgenerated from neighbouring mapchunks
 575                                 nplaced = U16_MAX;  // Disable top/filler placement
 576                                 air_above = false;
 577                                 water_above = false;
 578                         }
 579
 580                         vm->m_area.add_y(em, vi, -1);
 581                 }
 582         }
 583
 584         return stone_type;
 585 }
 586
 587
 588 void MapgenFractal::dustTopNodes()
 589 {
 590         if (node_max.Y < water_level)
 591                 return;
 592
 593         v3s16 em = vm->m_area.getExtent();
 594         u32 index = 0;
 595
 596         for (s16 z = node_min.Z; z <= node_max.Z; z++)
 597         for (s16 x = node_min.X; x <= node_max.X; x++, index++) {
 598                 Biome *biome = (Biome *)bmgr->getRaw(biomemap[index]);
 599
 600                 if (biome->c_dust == CONTENT_IGNORE)
 601                         continue;
 602
 603                 u32 vi = vm->m_area.index(x, full_node_max.Y, z);
 604                 content_t c_full_max = vm->m_data[vi].getContent();
 605                 s16 y_start;
 606
 607                 if (c_full_max == CONTENT_AIR) {
 608                         y_start = full_node_max.Y - 1;
 609                 } else if (c_full_max == CONTENT_IGNORE) {
 610                         vi = vm->m_area.index(x, node_max.Y + 1, z);
 611                         content_t c_max = vm->m_data[vi].getContent();
 612
 613                         if (c_max == CONTENT_AIR)
 614                                 y_start = node_max.Y;
 615                         else
 616                                 continue;
 617                 } else {
 618                         continue;
 619                 }
 620
 621                 vi = vm->m_area.index(x, y_start, z);
 622                 for (s16 y = y_start; y >= node_min.Y - 1; y--) {
 623                         if (vm->m_data[vi].getContent() != CONTENT_AIR)
 624                                 break;
 625
 626                         vm->m_area.add_y(em, vi, -1);
 627                 }
 628
 629                 content_t c = vm->m_data[vi].getContent();
 630                 if (!ndef->get(c).buildable_to && c != CONTENT_IGNORE && c != biome->c_dust) {
 631                         vm->m_area.add_y(em, vi, 1);
 632                         vm->m_data[vi] = MapNode(biome->c_dust);
 633                 }
 634         }
 635 }
 636
 637
 638 void MapgenFractal::generateCaves(s16 max_stone_y)
 639 {
 640         if (max_stone_y >= node_min.Y) {
 641                 u32 index = 0;
 642
 643                 for (s16 z = node_min.Z; z <= node_max.Z; z++)
 644                 for (s16 y = node_min.Y - 1; y <= node_max.Y + 1; y++) {
 645                         u32 vi = vm->m_area.index(node_min.X, y, z);
 646                         for (s16 x = node_min.X; x <= node_max.X; x++, vi++, index++) {
 647                                 float d1 = contour(noise_cave1->result[index]);
 648                                 float d2 = contour(noise_cave2->result[index]);
 649                                 if (d1 * d2 > 0.4f) {
 650                                         content_t c = vm->m_data[vi].getContent();
 651                                         if (!ndef->get(c).is_ground_content || c == CONTENT_AIR)
 652                                                 continue;
 653
 654                                         vm->m_data[vi] = MapNode(CONTENT_AIR);
 655                                 }
 656                         }
 657                 }
 658         }
 659
 660         if (node_max.Y > MGFRACTAL_LARGE_CAVE_DEPTH)
 661                 return;
 662
 663         PseudoRandom ps(blockseed + 21343);
 664         u32 bruises_count = (ps.range(1, 4) == 1) ? ps.range(1, 2) : 0;
 665         for (u32 i = 0; i < bruises_count; i++) {
 666                 CaveV5 cave(this, &ps);
 667                 cave.makeCave(node_min, node_max, max_stone_y);
 668         }
 669 }