src/mapgen_v7.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 "profiler.h"
  31 #include "settings.h" // For g_settings
  32 #include "main.h" // For g_profiler
  33 #include "emerge.h"
  34 #include "dungeongen.h"
  35 #include "cavegen.h"
  36 #include "treegen.h"
  37 #include "biome.h"
  38 #include "mapgen_v7.h"
  39
  40
  41 FlagDesc flagdesc_mapgen_v7[] = {
  42         {"mountains", MGV7_MOUNTAINS},
  43         {"ridges",    MGV7_RIDGES},
  44         {NULL,        0}
  45 };
  46
  47 ///////////////////////////////////////////////////////////////////////////////
  48
  49
  50 MapgenV7::MapgenV7(int mapgenid, MapgenParams *params, EmergeManager *emerge) {
  51         this->generating  = false;
  52         this->id     = mapgenid;
  53         this->emerge = emerge;
  54         this->bmgr   = emerge->biomedef;
  55
  56         this->seed        = (int)params->seed;
  57         this->water_level = params->water_level;
  58         this->flags       = params->flags;
  59         this->gennotify   = emerge->gennotify;
  60
  61         this->csize   = v3s16(1, 1, 1) * params->chunksize * MAP_BLOCKSIZE;
  62
  63         // amount of elements to skip for the next index
  64         // for noise/height/biome maps (not vmanip)
  65         this->ystride = csize.X;
  66         this->zstride = csize.X * csize.Y;
  67
  68         this->biomemap  = new u8[csize.X * csize.Z];
  69         this->heightmap = new s16[csize.X * csize.Z];
  70         this->ridge_heightmap = new s16[csize.X * csize.Z];
  71
  72         MapgenV7Params *sp = (MapgenV7Params *)params->sparams;
  73
  74         // Terrain noise
  75         noise_terrain_base    = new Noise(&sp->np_terrain_base,    seed, csize.X, csize.Z);
  76         noise_terrain_alt     = new Noise(&sp->np_terrain_alt,     seed, csize.X, csize.Z);
  77         noise_terrain_persist = new Noise(&sp->np_terrain_persist, seed, csize.X, csize.Z);
  78         noise_height_select   = new Noise(&sp->np_height_select,   seed, csize.X, csize.Z);
  79         noise_filler_depth    = new Noise(&sp->np_filler_depth,    seed, csize.X, csize.Z);
  80         noise_mount_height    = new Noise(&sp->np_mount_height,    seed, csize.X, csize.Z);
  81         noise_ridge_uwater    = new Noise(&sp->np_ridge_uwater,    seed, csize.X, csize.Z);
  82
  83         // 3d terrain noise
  84         noise_mountain = new Noise(&sp->np_mountain, seed, csize.X, csize.Y, csize.Z);
  85         noise_ridge    = new Noise(&sp->np_ridge,    seed, csize.X, csize.Y, csize.Z);
  86
  87         // Biome noise
  88         noise_heat     = new Noise(bmgr->np_heat,     seed, csize.X, csize.Z);
  89         noise_humidity = new Noise(bmgr->np_humidity, seed, csize.X, csize.Z);
  90 }
  91
  92
  93 MapgenV7::~MapgenV7() {
  94         delete noise_terrain_base;
  95         delete noise_terrain_persist;
  96         delete noise_height_select;
  97         delete noise_terrain_alt;
  98         delete noise_filler_depth;
  99         delete noise_mount_height;
 100         delete noise_ridge_uwater;
 101         delete noise_mountain;
 102         delete noise_ridge;
 103
 104         delete noise_heat;
 105         delete noise_humidity;
 106
 107         delete[] ridge_heightmap;
 108         delete[] heightmap;
 109         delete[] biomemap;
 110 }
 111
 112
 113 MapgenV7Params::MapgenV7Params() {
 114         spflags = MGV7_MOUNTAINS | MGV7_RIDGES;
 115
 116         np_terrain_base    = NoiseParams(4,    70,  v3f(300, 300, 300), 82341, 6, 0.7);
 117         np_terrain_alt     = NoiseParams(4,    25,  v3f(600, 600, 600), 5934,  5, 0.6);
 118         np_terrain_persist = NoiseParams(0.6,  0.1, v3f(500, 500, 500), 539,   3, 0.6);
 119         np_height_select   = NoiseParams(-0.5, 1,   v3f(250, 250, 250), 4213,  5, 0.69);
 120         np_filler_depth    = NoiseParams(0,    1.2, v3f(150, 150, 150), 261,   4, 0.7);
 121         np_mount_height    = NoiseParams(100,  30,  v3f(500, 500, 500), 72449, 4, 0.6);
 122         np_ridge_uwater    = NoiseParams(0,    1,   v3f(500, 500, 500), 85039, 4, 0.6);
 123         np_mountain        = NoiseParams(0,    1,   v3f(250, 350, 250), 5333,  5, 0.68);
 124         np_ridge           = NoiseParams(0,    1,   v3f(100, 100, 100), 6467,  4, 0.75);
 125 }
 126
 127
 128 void MapgenV7Params::readParams(Settings *settings) {
 129         settings->getFlagStrNoEx("mgv7_spflags", spflags, flagdesc_mapgen_v7);
 130
 131         settings->getNoiseParams("mgv7_np_terrain_base",    np_terrain_base);
 132         settings->getNoiseParams("mgv7_np_terrain_alt",     np_terrain_alt);
 133         settings->getNoiseParams("mgv7_np_terrain_persist", np_terrain_persist);
 134         settings->getNoiseParams("mgv7_np_height_select",   np_height_select);
 135         settings->getNoiseParams("mgv7_np_filler_depth",    np_filler_depth);
 136         settings->getNoiseParams("mgv7_np_mount_height",    np_mount_height);
 137         settings->getNoiseParams("mgv7_np_ridge_uwater",    np_ridge_uwater);
 138         settings->getNoiseParams("mgv7_np_mountain",        np_mountain);
 139         settings->getNoiseParams("mgv7_np_ridge",           np_ridge);
 140 }
 141
 142
 143 void MapgenV7Params::writeParams(Settings *settings) {
 144         settings->setFlagStr("mgv7_spflags", spflags, flagdesc_mapgen_v7, (u32)-1);
 145
 146         settings->setNoiseParams("mgv7_np_terrain_base",    np_terrain_base);
 147         settings->setNoiseParams("mgv7_np_terrain_alt",     np_terrain_alt);
 148         settings->setNoiseParams("mgv7_np_terrain_persist", np_terrain_persist);
 149         settings->setNoiseParams("mgv7_np_height_select",   np_height_select);
 150         settings->setNoiseParams("mgv7_np_filler_depth",    np_filler_depth);
 151         settings->setNoiseParams("mgv7_np_mount_height",    np_mount_height);
 152         settings->setNoiseParams("mgv7_np_ridge_uwater",    np_ridge_uwater);
 153         settings->setNoiseParams("mgv7_np_mountain",        np_mountain);
 154         settings->setNoiseParams("mgv7_np_ridge",           np_ridge);
 155 }
 156
 157
 158 ///////////////////////////////////////
 159
 160
 161 int MapgenV7::getGroundLevelAtPoint(v2s16 p) {
 162         // Base terrain calculation
 163         s16 y = baseTerrainLevelAtPoint(p.X, p.Y);
 164
 165         // Ridge/river terrain calculation
 166         float width = 0.3;
 167         float uwatern = NoisePerlin2DNoTxfm(noise_ridge_uwater->np, p.X, p.Y, seed) * 2;
 168         // actually computing the depth of the ridge is much more expensive;
 169         // if inside a river, simply guess
 170         if (uwatern >= -width && uwatern <= width)
 171                 return water_level - 10;
 172
 173         // Mountain terrain calculation
 174         int iters = 128; // don't even bother iterating more than 128 times..
 175         while (iters--) {
 176                 //current point would have been air
 177                 if (!getMountainTerrainAtPoint(p.X, y, p.Y))
 178                         return y;
 179
 180                 y++;
 181         }
 182
 183         return y;
 184 }
 185
 186
 187 void MapgenV7::makeChunk(BlockMakeData *data) {
 188         assert(data->vmanip);
 189         assert(data->nodedef);
 190         assert(data->blockpos_requested.X >= data->blockpos_min.X &&
 191                    data->blockpos_requested.Y >= data->blockpos_min.Y &&
 192                    data->blockpos_requested.Z >= data->blockpos_min.Z);
 193         assert(data->blockpos_requested.X <= data->blockpos_max.X &&
 194                    data->blockpos_requested.Y <= data->blockpos_max.Y &&
 195                    data->blockpos_requested.Z <= data->blockpos_max.Z);
 196
 197         this->generating = true;
 198         this->vm   = data->vmanip;
 199         this->ndef = data->nodedef;
 200         //TimeTaker t("makeChunk");
 201
 202         v3s16 blockpos_min = data->blockpos_min;
 203         v3s16 blockpos_max = data->blockpos_max;
 204         node_min = blockpos_min * MAP_BLOCKSIZE;
 205         node_max = (blockpos_max + v3s16(1, 1, 1)) * MAP_BLOCKSIZE - v3s16(1, 1, 1);
 206         full_node_min = (blockpos_min - 1) * MAP_BLOCKSIZE;
 207         full_node_max = (blockpos_max + 2) * MAP_BLOCKSIZE - v3s16(1, 1, 1);
 208
 209         blockseed = emerge->getBlockSeed(full_node_min);  //////use getBlockSeed2()!
 210
 211         c_stone           = ndef->getId("mapgen_stone");
 212         c_dirt            = ndef->getId("mapgen_dirt");
 213         c_dirt_with_grass = ndef->getId("mapgen_dirt_with_grass");
 214         c_sand            = ndef->getId("mapgen_sand");
 215         c_water_source    = ndef->getId("mapgen_water_source");
 216         c_lava_source     = ndef->getId("mapgen_lava_source");
 217         c_ice             = ndef->getId("default:ice");
 218         if (c_ice == CONTENT_IGNORE)
 219                 c_ice = CONTENT_AIR;
 220
 221         // Make some noise
 222         calculateNoise();
 223
 224         // Generate base terrain, mountains, and ridges with initial heightmaps
 225         s16 stone_surface_max_y = generateTerrain();
 226
 227         updateHeightmap(node_min, node_max);
 228
 229         // Calculate biomes
 230         BiomeNoiseInput binput;
 231         binput.mapsize      = v2s16(csize.X, csize.Z);
 232         binput.heat_map     = noise_heat->result;
 233         binput.humidity_map = noise_humidity->result;
 234         binput.height_map   = heightmap;
 235         bmgr->calcBiomes(&binput, biomemap);
 236
 237         // Actually place the biome-specific nodes and what not
 238         generateBiomes();
 239
 240         if (flags & MG_CAVES)
 241                 generateCaves(stone_surface_max_y);
 242
 243         if (flags & MG_DUNGEONS) {
 244                 DungeonGen dgen(this, NULL);
 245                 dgen.generate(blockseed, full_node_min, full_node_max);
 246         }
 247
 248         for (size_t i = 0; i != emerge->decorations.size(); i++) {
 249                 Decoration *deco = emerge->decorations[i];
 250                 deco->placeDeco(this, blockseed + i, node_min, node_max);
 251         }
 252
 253         for (size_t i = 0; i != emerge->ores.size(); i++) {
 254                 Ore *ore = emerge->ores[i];
 255                 ore->placeOre(this, blockseed + i, node_min, node_max);
 256         }
 257
 258         // Sprinkle some dust on top after everything else was generated
 259         dustTopNodes();
 260
 261         //printf("makeChunk: %dms\n", t.stop());
 262
 263         updateLiquid(&data->transforming_liquid, full_node_min, full_node_max);
 264
 265         if (flags & MG_LIGHT)
 266                 calcLighting(node_min - v3s16(1, 0, 1) * MAP_BLOCKSIZE,
 267                                          node_max + v3s16(1, 0, 1) * MAP_BLOCKSIZE);
 268         //setLighting(node_min - v3s16(1, 0, 1) * MAP_BLOCKSIZE,
 269         //                      node_max + v3s16(1, 0, 1) * MAP_BLOCKSIZE, 0xFF);
 270
 271         this->generating = false;
 272 }
 273
 274
 275 void MapgenV7::calculateNoise() {
 276         //TimeTaker t("calculateNoise", NULL, PRECISION_MICRO);
 277         int x = node_min.X;
 278         int y = node_min.Y;
 279         int z = node_min.Z;
 280
 281         noise_height_select->perlinMap2D(x, z);
 282         noise_height_select->transformNoiseMap();
 283
 284         noise_terrain_persist->perlinMap2D(x, z);
 285         noise_terrain_persist->transformNoiseMap();
 286         float *persistmap = noise_terrain_persist->result;
 287         for (int i = 0; i != csize.X * csize.Z; i++)
 288                 persistmap[i] = rangelim(persistmap[i], 0.4, 0.9);
 289
 290         noise_terrain_base->perlinMap2DModulated(x, z, persistmap);
 291         noise_terrain_base->transformNoiseMap();
 292
 293         noise_terrain_alt->perlinMap2DModulated(x, z, persistmap);
 294         noise_terrain_alt->transformNoiseMap();
 295
 296         noise_filler_depth->perlinMap2D(x, z);
 297
 298         if (spflags & MGV7_MOUNTAINS) {
 299                 noise_mountain->perlinMap3D(x, y, z);
 300                 noise_mount_height->perlinMap2D(x, z);
 301                 noise_mount_height->transformNoiseMap();
 302         }
 303
 304         if (spflags & MGV7_RIDGES) {
 305                 noise_ridge->perlinMap3D(x, y, z);
 306                 noise_ridge_uwater->perlinMap2D(x, z);
 307         }
 308
 309         noise_heat->perlinMap2D(x, z);
 310         noise_humidity->perlinMap2D(x, z);
 311
 312         //printf("calculateNoise: %dus\n", t.stop());
 313 }
 314
 315
 316 Biome *MapgenV7::getBiomeAtPoint(v3s16 p) {
 317         float heat      = NoisePerlin2D(bmgr->np_heat, p.X, p.Z, seed);
 318         float humidity  = NoisePerlin2D(bmgr->np_humidity, p.X, p.Z, seed);
 319         s16 groundlevel = baseTerrainLevelAtPoint(p.X, p.Z);
 320
 321         return bmgr->getBiome(heat, humidity, groundlevel);
 322 }
 323
 324 //needs to be updated
 325 float MapgenV7::baseTerrainLevelAtPoint(int x, int z) {
 326         float hselect = NoisePerlin2D(noise_height_select->np, x, z, seed);
 327         hselect = rangelim(hselect, 0.0, 1.0);
 328
 329         float persist = NoisePerlin2D(noise_terrain_persist->np, x, z, seed);
 330         persist = rangelim(persist, 0.4, 0.9);
 331
 332         noise_terrain_base->np->persist = persist;
 333         float height_base = NoisePerlin2D(noise_terrain_base->np, x, z, seed);
 334
 335         noise_terrain_alt->np->persist = persist;
 336         float height_alt = NoisePerlin2D(noise_terrain_alt->np, x, z, seed);
 337
 338         if (height_alt > height_base)
 339                 return height_alt;
 340
 341         return (height_base * hselect) + (height_alt * (1.0 - hselect));
 342 }
 343
 344
 345 float MapgenV7::baseTerrainLevelFromMap(int index) {
 346         float hselect     = rangelim(noise_height_select->result[index], 0.0, 1.0);
 347         float height_base = noise_terrain_base->result[index];
 348         float height_alt  = noise_terrain_alt->result[index];
 349
 350         if (height_alt > height_base)
 351                 return height_alt;
 352
 353         return (height_base * hselect) + (height_alt * (1.0 - hselect));
 354 }
 355
 356
 357 bool MapgenV7::getMountainTerrainAtPoint(int x, int y, int z) {
 358         float mnt_h_n = NoisePerlin2D(noise_mount_height->np, x, z, seed);
 359         float height_modifier = -((float)y / rangelim(mnt_h_n, 80.0, 150.0));
 360         float mnt_n = NoisePerlin3D(noise_mountain->np, x, y, z, seed);
 361
 362         return mnt_n + height_modifier >= 0.6;
 363 }
 364
 365
 366 bool MapgenV7::getMountainTerrainFromMap(int idx_xyz, int idx_xz, int y) {
 367         float mounthn = noise_mount_height->result[idx_xz];
 368         float height_modifier = -((float)y / rangelim(mounthn, 80.0, 150.0));
 369         return (noise_mountain->result[idx_xyz] + height_modifier >= 0.6);
 370 }
 371
 372
 373 #if 0
 374 void MapgenV7::carveRivers() {
 375         MapNode n_air(CONTENT_AIR), n_water_source(c_water_source);
 376         MapNode n_stone(c_stone);
 377         u32 index = 0;
 378
 379         int river_depth = 4;
 380
 381         for (s16 z = node_min.Z; z <= node_max.Z; z++)
 382         for (s16 x = node_min.X; x <= node_max.X; x++, index++) {
 383                 float terrain_mod  = noise_terrain_mod->result[index];
 384                 NoiseParams *np = noise_terrain_river->np;
 385                 np->persist = noise_terrain_persist->result[index];
 386                 float terrain_river = NoisePerlin2DNoTxfm(np, x, z, seed);
 387                 float height = terrain_river * (1 - abs(terrain_mod)) *
 388                                                 noise_terrain_river->np->scale;
 389                 height = log(height * height); //log(h^3) is pretty interesting for terrain
 390
 391                 s16 y = heightmap[index];
 392                 if (height < 1.0 && y > river_depth &&
 393                         y - river_depth >= node_min.Y && y <= node_max.Y) {
 394
 395                         for (s16 ry = y; ry != y - river_depth; ry--) {
 396                                 u32 vi = vm->m_area.index(x, ry, z);
 397                                 vm->m_data[vi] = n_air;
 398                         }
 399
 400                         u32 vi = vm->m_area.index(x, y - river_depth, z);
 401                         vm->m_data[vi] = n_water_source;
 402                 }
 403         }
 404 }
 405 #endif
 406
 407
 408 int MapgenV7::generateTerrain() {
 409         int ymax = generateBaseTerrain();
 410
 411         if (spflags & MGV7_MOUNTAINS)
 412                 generateMountainTerrain();
 413
 414         if (spflags & MGV7_RIDGES)
 415                 generateRidgeTerrain();
 416
 417         return ymax;
 418 }
 419
 420
 421 int MapgenV7::generateBaseTerrain() {
 422         MapNode n_air(CONTENT_AIR);
 423         MapNode n_stone(c_stone);
 424         MapNode n_water(c_water_source);
 425
 426         int stone_surface_max_y = -MAP_GENERATION_LIMIT;
 427         v3s16 em = vm->m_area.getExtent();
 428         u32 index = 0;
 429
 430         for (s16 z = node_min.Z; z <= node_max.Z; z++)
 431         for (s16 x = node_min.X; x <= node_max.X; x++, index++) {
 432                 float surface_height = baseTerrainLevelFromMap(index);
 433                 s16 surface_y = (s16)surface_height;
 434
 435                 heightmap[index]       = surface_y;
 436                 ridge_heightmap[index] = surface_y;
 437
 438                 if (surface_y > stone_surface_max_y)
 439                         stone_surface_max_y = surface_y;
 440
 441                 u32 i = vm->m_area.index(x, node_min.Y, z);
 442                 for (s16 y = node_min.Y; y <= node_max.Y; y++) {
 443                         if (vm->m_data[i].getContent() == CONTENT_IGNORE) {
 444                                 if (y <= surface_y)
 445                                         vm->m_data[i] = n_stone;
 446                                 else if (y <= water_level)
 447                                         vm->m_data[i] = n_water;
 448                                 else
 449                                         vm->m_data[i] = n_air;
 450                         }
 451                         vm->m_area.add_y(em, i, 1);
 452                 }
 453         }
 454
 455         return stone_surface_max_y;
 456 }
 457
 458
 459 void MapgenV7::generateMountainTerrain() {
 460         if (node_max.Y <= water_level)
 461                 return;
 462
 463         MapNode n_stone(c_stone);
 464         u32 j = 0;
 465
 466         for (s16 z = node_min.Z; z <= node_max.Z; z++)
 467         for (s16 y = node_min.Y; y <= node_max.Y; y++) {
 468                 u32 vi = vm->m_area.index(node_min.X, y, z);
 469                 for (s16 x = node_min.X; x <= node_max.X; x++) {
 470                         int index = (z - node_min.Z) * csize.X + (x - node_min.X);
 471
 472                         if (getMountainTerrainFromMap(j, index, y))
 473                                 vm->m_data[vi] = n_stone;
 474
 475                         vi++;
 476                         j++;
 477                 }
 478         }
 479 }
 480
 481
 482 void MapgenV7::generateRidgeTerrain() {
 483         MapNode n_water(c_water_source);
 484         MapNode n_air(CONTENT_AIR);
 485         u32 index = 0;
 486
 487         for (s16 z = node_min.Z; z <= node_max.Z; z++)
 488         for (s16 y = node_min.Y; y <= node_max.Y; y++) {
 489                 u32 vi = vm->m_area.index(node_min.X, y, z);
 490                 for (s16 x = node_min.X; x <= node_max.X; x++, index++, vi++) {
 491                         int j = (z - node_min.Z) * csize.X + (x - node_min.X);
 492
 493                         if (heightmap[j] < water_level - 4)
 494                                 continue;
 495
 496                         float widthn = (noise_terrain_persist->result[j] - 0.6) / 0.1;
 497                         //widthn = rangelim(widthn, -0.05, 0.5);
 498
 499                         float width = 0.3; // TODO: figure out acceptable perlin noise values
 500                         float uwatern = noise_ridge_uwater->result[j] * 2;
 501                         if (uwatern < -width || uwatern > width)
 502                                 continue;
 503
 504                         float height_mod = (float)(y + 17) / 2.5;
 505                         float width_mod  = (width - fabs(uwatern));
 506                         float nridge = noise_ridge->result[index] * (float)y / 7.0;
 507
 508                         if (y < water_level)
 509                                 nridge = -fabs(nridge) * 3.0 * widthn * 0.3;
 510
 511                         if (nridge + width_mod * height_mod < 0.6)
 512                                 continue;
 513
 514                         if (y < ridge_heightmap[j])
 515                                 ridge_heightmap[j] = y - 1;
 516
 517                         vm->m_data[vi] = (y > water_level) ? n_air : n_water;
 518                 }
 519         }
 520 }
 521
 522
 523 void MapgenV7::generateBiomes() {
 524         if (node_max.Y < water_level)
 525                 return;
 526
 527         MapNode n_air(CONTENT_AIR);
 528         MapNode n_stone(c_stone);
 529         MapNode n_water(c_water_source);
 530
 531         v3s16 em = vm->m_area.getExtent();
 532         u32 index = 0;
 533
 534         for (s16 z = node_min.Z; z <= node_max.Z; z++)
 535         for (s16 x = node_min.X; x <= node_max.X; x++, index++) {
 536                 Biome *biome  = bmgr->biomes[biomemap[index]];
 537                 s16 dfiller   = biome->depth_filler + noise_filler_depth->result[index];
 538                 s16 y0_top    = biome->depth_top;
 539                 s16 y0_filler = biome->depth_filler + biome->depth_top + dfiller;
 540
 541                 s16 nplaced = 0;
 542                 u32 i = vm->m_area.index(x, node_max.Y, z);
 543
 544                 content_t c_above = vm->m_data[i + em.X].getContent();
 545                 bool have_air = c_above == CONTENT_AIR;
 546
 547                 for (s16 y = node_max.Y; y >= node_min.Y; y--) {
 548                         content_t c = vm->m_data[i].getContent();
 549
 550                         // It could be the case that the elevation is equal to the chunk
 551                         // boundary, but the chunk above has not been generated yet
 552                         if (y == node_max.Y && c_above == CONTENT_IGNORE &&
 553                                 y == heightmap[index] && c == c_stone) {
 554                                 int j = (z - node_min.Z) * zstride +
 555                                                 (y - node_min.Y) * ystride +
 556                                                 (x - node_min.X);
 557                                 have_air = !getMountainTerrainFromMap(j, index, y);
 558                         }
 559
 560                         if (c == c_stone && have_air) {
 561                                 content_t c_below = vm->m_data[i - em.X].getContent();
 562
 563                                 if (c_below != CONTENT_AIR) {
 564                                         if (nplaced < y0_top) {
 565                                                 // A hack to prevent dirt_with_grass from being
 566                                                 // placed below water.  TODO: fix later
 567                                                 content_t c_place = ((y < water_level) &&
 568                                                                 (biome->c_top == c_dirt_with_grass)) ?
 569                                                                  c_dirt : biome->c_top;
 570
 571                                                 vm->m_data[i] = MapNode(c_place);
 572                                                 nplaced++;
 573                                         } else if (nplaced < y0_filler && nplaced >= y0_top) {
 574                                                 vm->m_data[i] = MapNode(biome->c_filler);
 575                                                 nplaced++;
 576                                         } else {
 577                                                 have_air = false;
 578                                                 nplaced  = 0;
 579                                         }
 580                                 }
 581                         } else if (c == c_water_source) {
 582                                 have_air = true;
 583                                 nplaced = 0;
 584                                 vm->m_data[i] = MapNode(biome->c_water);
 585                         } else if (c == CONTENT_AIR) {
 586                                 have_air = true;
 587                                 nplaced = 0;
 588                         }
 589
 590                         vm->m_area.add_y(em, i, -1);
 591                 }
 592         }
 593 }
 594
 595
 596 void MapgenV7::dustTopNodes() {
 597         v3s16 em = vm->m_area.getExtent();
 598         u32 index = 0;
 599
 600         if (water_level > node_max.Y)
 601                 return;
 602
 603         for (s16 z = node_min.Z; z <= node_max.Z; z++)
 604         for (s16 x = node_min.X; x <= node_max.X; x++, index++) {
 605                 Biome *biome = bmgr->biomes[biomemap[index]];
 606
 607                 if (biome->c_dust == CONTENT_IGNORE)
 608                         continue;
 609
 610                 s16 y = node_max.Y;
 611                 u32 vi = vm->m_area.index(x, y, z);
 612                 for (; y >= node_min.Y; y--) {
 613                         if (vm->m_data[vi].getContent() != CONTENT_AIR)
 614                                 break;
 615
 616                         vm->m_area.add_y(em, vi, -1);
 617                 }
 618
 619                 content_t c = vm->m_data[vi].getContent();
 620                 if (c == biome->c_water && biome->c_dust_water != CONTENT_IGNORE) {
 621                         if (y < node_min.Y)
 622                                 continue;
 623
 624                         vm->m_data[vi] = MapNode(biome->c_dust_water);
 625                 } else if (!ndef->get(c).buildable_to && c != CONTENT_IGNORE) {
 626                         if (y == node_max.Y)
 627                                 continue;
 628
 629                         vm->m_area.add_y(em, vi, 1);
 630                         vm->m_data[vi] = MapNode(biome->c_dust);
 631                 }
 632         }
 633 }
 634
 635
 636 #if 0
 637 void MapgenV7::addTopNodes() {
 638         v3s16 em = vm->m_area.getExtent();
 639         s16 ntopnodes;
 640         u32 index = 0;
 641
 642         for (s16 z = node_min.Z; z <= node_max.Z; z++)
 643         for (s16 x = node_min.X; x <= node_max.X; x++, index++) {
 644                 Biome *biome = bmgr->biomes[biomemap[index]];
 645
 646                 //////////////////// First, add top nodes below the ridge
 647                 s16 y = ridge_heightmap[index];
 648
 649                 // This cutoff is good enough, but not perfect.
 650                 // It will cut off potentially placed top nodes at chunk boundaries
 651                 if (y < node_min.Y)
 652                         continue;
 653                 if (y > node_max.Y) {
 654                         y = node_max.Y; // Let's see if we can still go downward anyway
 655                         u32 vi = vm->m_area.index(x, y, z);
 656                         content_t c = vm->m_data[vi].getContent();
 657                         if (ndef->get(c).walkable)
 658                                 continue;
 659                 }
 660
 661                 // N.B.  It is necessary to search downward since ridge_heightmap[i]
 662                 // might not be the actual height, just the lowest part in the chunk
 663                 // where a ridge had been carved
 664                 u32 i = vm->m_area.index(x, y, z);
 665                 for (; y >= node_min.Y; y--) {
 666                         content_t c = vm->m_data[i].getContent();
 667                         if (ndef->get(c).walkable)
 668                                 break;
 669                         vm->m_area.add_y(em, i, -1);
 670                 }
 671
 672                 if (y != node_min.Y - 1 && y >= water_level) {
 673                         ridge_heightmap[index] = y; //update ridgeheight
 674                         ntopnodes = biome->top_depth;
 675                         for (; y <= node_max.Y && ntopnodes; y++) {
 676                                 ntopnodes--;
 677                                 vm->m_data[i] = MapNode(biome->c_top);
 678                                 vm->m_area.add_y(em, i, 1);
 679                         }
 680                         // If dirt, grow grass on it.
 681                         if (y > water_level - 10 &&
 682                                 vm->m_data[i].getContent() == CONTENT_AIR) {
 683                                 vm->m_area.add_y(em, i, -1);
 684                                 if (vm->m_data[i].getContent() == c_dirt)
 685                                         vm->m_data[i] = MapNode(c_dirt_with_grass);
 686                         }
 687                 }
 688
 689                 //////////////////// Now, add top nodes on top of the ridge
 690                 y = heightmap[index];
 691                 if (y > node_max.Y) {
 692                         y = node_max.Y; // Let's see if we can still go downward anyway
 693                         u32 vi = vm->m_area.index(x, y, z);
 694                         content_t c = vm->m_data[vi].getContent();
 695                         if (ndef->get(c).walkable)
 696                                 continue;
 697                 }
 698
 699                 i = vm->m_area.index(x, y, z);
 700                 for (; y >= node_min.Y; y--) {
 701                         content_t c = vm->m_data[i].getContent();
 702                         if (ndef->get(c).walkable)
 703                                 break;
 704                         vm->m_area.add_y(em, i, -1);
 705                 }
 706
 707                 if (y != node_min.Y - 1) {
 708                         ntopnodes = biome->top_depth;
 709                         // Let's see if we've already added it...
 710                         if (y == ridge_heightmap[index] + ntopnodes - 1)
 711                                 continue;
 712
 713                         for (; y <= node_max.Y && ntopnodes; y++) {
 714                                 ntopnodes--;
 715                                 vm->m_data[i] = MapNode(biome->c_top);
 716                                 vm->m_area.add_y(em, i, 1);
 717                         }
 718                         // If dirt, grow grass on it.
 719                         if (y > water_level - 10 &&
 720                                 vm->m_data[i].getContent() == CONTENT_AIR) {
 721                                 vm->m_area.add_y(em, i, -1);
 722                                 if (vm->m_data[i].getContent() == c_dirt)
 723                                         vm->m_data[i] = MapNode(c_dirt_with_grass);
 724                         }
 725                 }
 726         }
 727 }
 728 #endif
 729
 730
 731 NoiseParams nparams_v7_def_cave(6, 6.0, v3f(250.0, 250.0, 250.0), 34329, 3, 0.50);
 732
 733 void MapgenV7::generateCaves(int max_stone_y) {
 734         PseudoRandom ps(blockseed + 21343);
 735
 736         int volume_nodes = (node_max.X - node_min.X + 1) *
 737                                            (node_max.Y - node_min.Y + 1) *
 738                                            (node_max.Z - node_min.Z + 1);
 739         float cave_amount = NoisePerlin2D(&nparams_v7_def_cave,
 740                                                                 node_min.X, node_min.Y, seed);
 741
 742         u32 caves_count = MYMAX(0.0, cave_amount) * volume_nodes / 250000;
 743         for (u32 i = 0; i < caves_count; i++) {
 744                 CaveV7 cave(this, &ps, false);
 745                 cave.makeCave(node_min, node_max, max_stone_y);
 746         }
 747
 748         u32 bruises_count = (ps.range(1, 8) == 1) ? ps.range(0, ps.range(0, 2)) : 1;
 749         for (u32 i = 0; i < bruises_count; i++) {
 750                 CaveV7 cave(this, &ps, true);
 751                 cave.makeCave(node_min, node_max, max_stone_y);
 752         }
 753 }