src/mapgen_v7.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_v7.h"
  41
  42
  43 FlagDesc flagdesc_mapgen_v7[] = {
  44         {"mountains", MGV7_MOUNTAINS},
  45         {"ridges",    MGV7_RIDGES},
  46         {NULL,        0}
  47 };
  48
  49
  50 ///////////////////////////////////////////////////////////////////////////////
  51
  52
  53 MapgenV7::MapgenV7(int mapgenid, MapgenParams *params, EmergeManager *emerge)
  54         : MapgenBasic(mapgenid, params, emerge)
  55 {
  56         MapgenV7Params *sp = (MapgenV7Params *)params->sparams;
  57
  58         this->spflags    = sp->spflags;
  59         this->cave_width = sp->cave_width;
  60
  61         //// Terrain noise
  62         noise_terrain_base    = new Noise(&sp->np_terrain_base,    seed, csize.X, csize.Z);
  63         noise_terrain_alt     = new Noise(&sp->np_terrain_alt,     seed, csize.X, csize.Z);
  64         noise_terrain_persist = new Noise(&sp->np_terrain_persist, seed, csize.X, csize.Z);
  65         noise_height_select   = new Noise(&sp->np_height_select,   seed, csize.X, csize.Z);
  66         noise_filler_depth    = new Noise(&sp->np_filler_depth,    seed, csize.X, csize.Z);
  67         noise_mount_height    = new Noise(&sp->np_mount_height,    seed, csize.X, csize.Z);
  68         noise_ridge_uwater    = new Noise(&sp->np_ridge_uwater,    seed, csize.X, csize.Z);
  69
  70         //// 3d terrain noise
  71         // 1-up 1-down overgeneration
  72         noise_mountain = new Noise(&sp->np_mountain, seed, csize.X, csize.Y + 2, csize.Z);
  73         noise_ridge    = new Noise(&sp->np_ridge,    seed, csize.X, csize.Y + 2, csize.Z);
  74
  75         MapgenBasic::np_cave1 = sp->np_cave1;
  76         MapgenBasic::np_cave2 = sp->np_cave2;
  77 }
  78
  79
  80 MapgenV7::~MapgenV7()
  81 {
  82         delete noise_terrain_base;
  83         delete noise_terrain_persist;
  84         delete noise_height_select;
  85         delete noise_terrain_alt;
  86         delete noise_filler_depth;
  87         delete noise_mount_height;
  88         delete noise_ridge_uwater;
  89         delete noise_mountain;
  90         delete noise_ridge;
  91 }
  92
  93
  94 MapgenV7Params::MapgenV7Params()
  95 {
  96         spflags    = MGV7_MOUNTAINS | MGV7_RIDGES;
  97         cave_width = 0.2;
  98
  99         np_terrain_base    = NoiseParams(4,    70,  v3f(600,  600,  600),  82341, 5, 0.6,  2.0);
 100         np_terrain_alt     = NoiseParams(4,    25,  v3f(600,  600,  600),  5934,  5, 0.6,  2.0);
 101         np_terrain_persist = NoiseParams(0.6,  0.1, v3f(2000, 2000, 2000), 539,   3, 0.6,  2.0);
 102         np_height_select   = NoiseParams(-8,   16,  v3f(500,  500,  500),  4213,  6, 0.7,  2.0);
 103         np_filler_depth    = NoiseParams(0,    1.2, v3f(150,  150,  150),  261,   3, 0.7,  2.0);
 104         np_mount_height    = NoiseParams(256,  112, v3f(1000, 1000, 1000), 72449, 3, 0.6,  2.0);
 105         np_ridge_uwater    = NoiseParams(0,    1,   v3f(1000, 1000, 1000), 85039, 5, 0.6,  2.0);
 106         np_mountain        = NoiseParams(-0.6, 1,   v3f(250,  350,  250),  5333,  5, 0.63, 2.0);
 107         np_ridge           = NoiseParams(0,    1,   v3f(100,  100,  100),  6467,  4, 0.75, 2.0);
 108         np_cave1           = NoiseParams(0,    12,  v3f(61,   61,   61),   52534, 3, 0.5,  2.0);
 109         np_cave2           = NoiseParams(0,    12,  v3f(67,   67,   67),   10325, 3, 0.5,  2.0);
 110 }
 111
 112
 113 void MapgenV7Params::readParams(const Settings *settings)
 114 {
 115         settings->getFlagStrNoEx("mgv7_spflags",  spflags, flagdesc_mapgen_v7);
 116         settings->getFloatNoEx("mgv7_cave_width", cave_width);
 117
 118         settings->getNoiseParams("mgv7_np_terrain_base",    np_terrain_base);
 119         settings->getNoiseParams("mgv7_np_terrain_alt",     np_terrain_alt);
 120         settings->getNoiseParams("mgv7_np_terrain_persist", np_terrain_persist);
 121         settings->getNoiseParams("mgv7_np_height_select",   np_height_select);
 122         settings->getNoiseParams("mgv7_np_filler_depth",    np_filler_depth);
 123         settings->getNoiseParams("mgv7_np_mount_height",    np_mount_height);
 124         settings->getNoiseParams("mgv7_np_ridge_uwater",    np_ridge_uwater);
 125         settings->getNoiseParams("mgv7_np_mountain",        np_mountain);
 126         settings->getNoiseParams("mgv7_np_ridge",           np_ridge);
 127         settings->getNoiseParams("mgv7_np_cave1",           np_cave1);
 128         settings->getNoiseParams("mgv7_np_cave2",           np_cave2);
 129 }
 130
 131
 132 void MapgenV7Params::writeParams(Settings *settings) const
 133 {
 134         settings->setFlagStr("mgv7_spflags",  spflags, flagdesc_mapgen_v7, U32_MAX);
 135         settings->setFloat("mgv7_cave_width", cave_width);
 136
 137         settings->setNoiseParams("mgv7_np_terrain_base",    np_terrain_base);
 138         settings->setNoiseParams("mgv7_np_terrain_alt",     np_terrain_alt);
 139         settings->setNoiseParams("mgv7_np_terrain_persist", np_terrain_persist);
 140         settings->setNoiseParams("mgv7_np_height_select",   np_height_select);
 141         settings->setNoiseParams("mgv7_np_filler_depth",    np_filler_depth);
 142         settings->setNoiseParams("mgv7_np_mount_height",    np_mount_height);
 143         settings->setNoiseParams("mgv7_np_ridge_uwater",    np_ridge_uwater);
 144         settings->setNoiseParams("mgv7_np_mountain",        np_mountain);
 145         settings->setNoiseParams("mgv7_np_ridge",           np_ridge);
 146         settings->setNoiseParams("mgv7_np_cave1",           np_cave1);
 147         settings->setNoiseParams("mgv7_np_cave2",           np_cave2);
 148 }
 149
 150
 151 ///////////////////////////////////////////////////////////////////////////////
 152
 153
 154 int MapgenV7::getSpawnLevelAtPoint(v2s16 p)
 155 {
 156         // Base terrain calculation
 157         s16 y = baseTerrainLevelAtPoint(p.X, p.Y);
 158
 159         // Ridge/river terrain calculation
 160         float width = 0.2;
 161         float uwatern = NoisePerlin2D(&noise_ridge_uwater->np, p.X, p.Y, seed) * 2;
 162         // if inside a river this is an unsuitable spawn point
 163         if (fabs(uwatern) <= width)
 164                 return MAX_MAP_GENERATION_LIMIT;
 165
 166         // Mountain terrain calculation
 167         int iters = 128;
 168         while (iters--) {
 169                 if (!getMountainTerrainAtPoint(p.X, y + 1, p.Y)) {  // Air, y is ground level
 170                         if (y <= water_level || y > water_level + 16)
 171                                 return MAX_MAP_GENERATION_LIMIT;  // Unsuitable spawn point
 172                         else
 173                                 return y;
 174                 }
 175                 y++;
 176         }
 177
 178         // Unsuitable spawn point, no ground surface found
 179         return MAX_MAP_GENERATION_LIMIT;
 180 }
 181
 182
 183 void MapgenV7::makeChunk(BlockMakeData *data)
 184 {
 185         // Pre-conditions
 186         assert(data->vmanip);
 187         assert(data->nodedef);
 188         assert(data->blockpos_requested.X >= data->blockpos_min.X &&
 189                 data->blockpos_requested.Y >= data->blockpos_min.Y &&
 190                 data->blockpos_requested.Z >= data->blockpos_min.Z);
 191         assert(data->blockpos_requested.X <= data->blockpos_max.X &&
 192                 data->blockpos_requested.Y <= data->blockpos_max.Y &&
 193                 data->blockpos_requested.Z <= data->blockpos_max.Z);
 194
 195         this->generating = true;
 196         this->vm   = data->vmanip;
 197         this->ndef = data->nodedef;
 198         //TimeTaker t("makeChunk");
 199
 200         v3s16 blockpos_min = data->blockpos_min;
 201         v3s16 blockpos_max = data->blockpos_max;
 202         node_min = blockpos_min * MAP_BLOCKSIZE;
 203         node_max = (blockpos_max + v3s16(1, 1, 1)) * MAP_BLOCKSIZE - v3s16(1, 1, 1);
 204         full_node_min = (blockpos_min - 1) * MAP_BLOCKSIZE;
 205         full_node_max = (blockpos_max + 2) * MAP_BLOCKSIZE - v3s16(1, 1, 1);
 206
 207         blockseed = getBlockSeed2(full_node_min, seed);
 208
 209         // Generate base and mountain terrain
 210         // An initial heightmap is no longer created here for use in generateRidgeTerrain()
 211         s16 stone_surface_max_y = generateTerrain();
 212
 213         // Generate rivers
 214         if (spflags & MGV7_RIDGES)
 215                 generateRidgeTerrain();
 216
 217         // Create heightmap
 218         updateHeightmap(node_min, node_max);
 219
 220         // Init biome generator, place biome-specific nodes, and build biomemap
 221         biomegen->calcBiomeNoise(node_min);
 222         MgStoneType stone_type = generateBiomes();
 223
 224         if (flags & MG_CAVES)
 225                 generateCaves(stone_surface_max_y, water_level);
 226
 227         if (flags & MG_DUNGEONS)
 228                 generateDungeons(stone_surface_max_y, stone_type);
 229
 230         // Generate the registered decorations
 231         if (flags & MG_DECORATIONS)
 232                 m_emerge->decomgr->placeAllDecos(this, blockseed, node_min, node_max);
 233
 234         // Generate the registered ores
 235         m_emerge->oremgr->placeAllOres(this, blockseed, node_min, node_max);
 236
 237         // Sprinkle some dust on top after everything else was generated
 238         dustTopNodes();
 239
 240         //printf("makeChunk: %dms\n", t.stop());
 241
 242         updateLiquid(&data->transforming_liquid, full_node_min, full_node_max);
 243
 244         if (flags & MG_LIGHT)
 245                 calcLighting(node_min - v3s16(0, 1, 0), node_max + v3s16(0, 1, 0),
 246                         full_node_min, full_node_max);
 247
 248         //setLighting(node_min - v3s16(1, 0, 1) * MAP_BLOCKSIZE,
 249         //                      node_max + v3s16(1, 0, 1) * MAP_BLOCKSIZE, 0xFF);
 250
 251         this->generating = false;
 252 }
 253
 254
 255 float MapgenV7::baseTerrainLevelAtPoint(s16 x, s16 z)
 256 {
 257         float hselect = NoisePerlin2D(&noise_height_select->np, x, z, seed);
 258         hselect = rangelim(hselect, 0.0, 1.0);
 259
 260         float persist = NoisePerlin2D(&noise_terrain_persist->np, x, z, seed);
 261
 262         noise_terrain_base->np.persist = persist;
 263         float height_base = NoisePerlin2D(&noise_terrain_base->np, x, z, seed);
 264
 265         noise_terrain_alt->np.persist = persist;
 266         float height_alt = NoisePerlin2D(&noise_terrain_alt->np, x, z, seed);
 267
 268         if (height_alt > height_base)
 269                 return height_alt;
 270
 271         return (height_base * hselect) + (height_alt * (1.0 - hselect));
 272 }
 273
 274
 275 float MapgenV7::baseTerrainLevelFromMap(int index)
 276 {
 277         float hselect     = rangelim(noise_height_select->result[index], 0.0, 1.0);
 278         float height_base = noise_terrain_base->result[index];
 279         float height_alt  = noise_terrain_alt->result[index];
 280
 281         if (height_alt > height_base)
 282                 return height_alt;
 283
 284         return (height_base * hselect) + (height_alt * (1.0 - hselect));
 285 }
 286
 287
 288 bool MapgenV7::getMountainTerrainAtPoint(s16 x, s16 y, s16 z)
 289 {
 290         float mnt_h_n = NoisePerlin2D(&noise_mount_height->np, x, z, seed);
 291         float density_gradient = -((float)y / mnt_h_n);
 292         float mnt_n = NoisePerlin3D(&noise_mountain->np, x, y, z, seed);
 293
 294         return mnt_n + density_gradient >= 0.0;
 295 }
 296
 297
 298 bool MapgenV7::getMountainTerrainFromMap(int idx_xyz, int idx_xz, s16 y)
 299 {
 300         float mounthn = noise_mount_height->result[idx_xz];
 301         float density_gradient = -((float)y / mounthn);
 302         float mountn = noise_mountain->result[idx_xyz];
 303
 304         return mountn + density_gradient >= 0.0;
 305 }
 306
 307
 308 int MapgenV7::generateTerrain()
 309 {
 310         MapNode n_air(CONTENT_AIR);
 311         MapNode n_stone(c_stone);
 312         MapNode n_water(c_water_source);
 313
 314         //// Calculate noise for terrain generation
 315         noise_terrain_persist->perlinMap2D(node_min.X, node_min.Z);
 316         float *persistmap = noise_terrain_persist->result;
 317
 318         noise_terrain_base->perlinMap2D(node_min.X, node_min.Z, persistmap);
 319         noise_terrain_alt->perlinMap2D(node_min.X, node_min.Z, persistmap);
 320         noise_height_select->perlinMap2D(node_min.X, node_min.Z);
 321
 322         if (spflags & MGV7_MOUNTAINS) {
 323                 noise_mountain->perlinMap3D(node_min.X, node_min.Y - 1, node_min.Z);
 324                 noise_mount_height->perlinMap2D(node_min.X, node_min.Z);
 325         }
 326
 327         //// Place nodes
 328         v3s16 em = vm->m_area.getExtent();
 329         s16 stone_surface_max_y = -MAX_MAP_GENERATION_LIMIT;
 330         u32 index2d = 0;
 331
 332         for (s16 z = node_min.Z; z <= node_max.Z; z++)
 333         for (s16 x = node_min.X; x <= node_max.X; x++, index2d++) {
 334                 s16 surface_y = baseTerrainLevelFromMap(index2d);
 335
 336                 if (surface_y > stone_surface_max_y)
 337                         stone_surface_max_y = surface_y;
 338
 339                 u32 vi = vm->m_area.index(x, node_min.Y - 1, z);
 340                 u32 index3d = (z - node_min.Z) * zstride_1u1d + (x - node_min.X);
 341
 342                 for (s16 y = node_min.Y - 1; y <= node_max.Y + 1; y++) {
 343                         if (vm->m_data[vi].getContent() == CONTENT_IGNORE) {
 344                                 if (y <= surface_y) {
 345                                         vm->m_data[vi] = n_stone;  // Base terrain
 346                                 } else if ((spflags & MGV7_MOUNTAINS) &&
 347                                                 getMountainTerrainFromMap(index3d, index2d, y)) {
 348                                         vm->m_data[vi] = n_stone;  // Mountain terrain
 349                                         if (y > stone_surface_max_y)
 350                                                 stone_surface_max_y = y;
 351                                 } else if (y <= water_level) {
 352                                         vm->m_data[vi] = n_water;
 353                                 } else {
 354                                         vm->m_data[vi] = n_air;
 355                                 }
 356                         }
 357                         vm->m_area.add_y(em, vi, 1);
 358                         index3d += ystride;
 359                 }
 360         }
 361
 362         return stone_surface_max_y;
 363 }
 364
 365
 366 void MapgenV7::generateRidgeTerrain()
 367 {
 368         if (node_max.Y < water_level - 16)
 369                 return;
 370
 371         noise_ridge->perlinMap3D(node_min.X, node_min.Y - 1, node_min.Z);
 372         noise_ridge_uwater->perlinMap2D(node_min.X, node_min.Z);
 373
 374         MapNode n_water(c_water_source);
 375         MapNode n_air(CONTENT_AIR);
 376         u32 index = 0;
 377         float width = 0.2;
 378
 379         for (s16 z = node_min.Z; z <= node_max.Z; z++)
 380         for (s16 y = node_min.Y - 1; y <= node_max.Y + 1; y++) {
 381                 u32 vi = vm->m_area.index(node_min.X, y, z);
 382                 for (s16 x = node_min.X; x <= node_max.X; x++, index++, vi++) {
 383                         int j = (z - node_min.Z) * csize.X + (x - node_min.X);
 384
 385                         float uwatern = noise_ridge_uwater->result[j] * 2;
 386                         if (fabs(uwatern) > width)
 387                                 continue;
 388
 389                         float altitude = y - water_level;
 390                         float height_mod = (altitude + 17) / 2.5;
 391                         float width_mod  = width - fabs(uwatern);
 392                         float nridge = noise_ridge->result[index] * MYMAX(altitude, 0) / 7.0;
 393
 394                         if (nridge + width_mod * height_mod < 0.6)
 395                                 continue;
 396
 397                         vm->m_data[vi] = (y > water_level) ? n_air : n_water;
 398                 }
 399         }
 400 }
 401
 402
 403 ////////////////////////////////////////////////////////////////////////////////
 404 //// Code Boneyard
 405 ////
 406 //// Much of the stuff here has potential to become useful again at some point
 407 //// in the future, but we don't want it to get lost or forgotten in version
 408 //// control.
 409 ////
 410
 411 #if 0
 412 int MapgenV7::generateMountainTerrain(s16 ymax)
 413 {
 414         MapNode n_stone(c_stone);
 415         u32 j = 0;
 416
 417         for (s16 z = node_min.Z; z <= node_max.Z; z++)
 418         for (s16 y = node_min.Y - 1; y <= node_max.Y + 1; y++) {
 419                 u32 vi = vm->m_area.index(node_min.X, y, z);
 420                 for (s16 x = node_min.X; x <= node_max.X; x++) {
 421                         int index = (z - node_min.Z) * csize.X + (x - node_min.X);
 422                         content_t c = vm->m_data[vi].getContent();
 423
 424                         if (getMountainTerrainFromMap(j, index, y)
 425                                         && (c == CONTENT_AIR || c == c_water_source)) {
 426                                 vm->m_data[vi] = n_stone;
 427                                 if (y > ymax)
 428                                         ymax = y;
 429                         }
 430
 431                         vi++;
 432                         j++;
 433                 }
 434         }
 435
 436         return ymax;
 437 }
 438 #endif
 439
 440
 441 #if 0
 442 void MapgenV7::carveRivers() {
 443         MapNode n_air(CONTENT_AIR), n_water_source(c_water_source);
 444         MapNode n_stone(c_stone);
 445         u32 index = 0;
 446
 447         int river_depth = 4;
 448
 449         for (s16 z = node_min.Z; z <= node_max.Z; z++)
 450         for (s16 x = node_min.X; x <= node_max.X; x++, index++) {
 451                 float terrain_mod  = noise_terrain_mod->result[index];
 452                 NoiseParams *np = noise_terrain_river->np;
 453                 np.persist = noise_terrain_persist->result[index];
 454                 float terrain_river = NoisePerlin2DNoTxfm(np, x, z, seed);
 455                 float height = terrain_river * (1 - abs(terrain_mod)) *
 456                                                 noise_terrain_river->np.scale;
 457                 height = log(height * height); //log(h^3) is pretty interesting for terrain
 458
 459                 s16 y = heightmap[index];
 460                 if (height < 1.0 && y > river_depth &&
 461                         y - river_depth >= node_min.Y && y <= node_max.Y) {
 462
 463                         for (s16 ry = y; ry != y - river_depth; ry--) {
 464                                 u32 vi = vm->m_area.index(x, ry, z);
 465                                 vm->m_data[vi] = n_air;
 466                         }
 467
 468                         u32 vi = vm->m_area.index(x, y - river_depth, z);
 469                         vm->m_data[vi] = n_water_source;
 470                 }
 471         }
 472 }
 473 #endif
 474
 475
 476 #if 0
 477 void MapgenV7::addTopNodes()
 478 {
 479         v3s16 em = vm->m_area.getExtent();
 480         s16 ntopnodes;
 481         u32 index = 0;
 482
 483         for (s16 z = node_min.Z; z <= node_max.Z; z++)
 484         for (s16 x = node_min.X; x <= node_max.X; x++, index++) {
 485                 Biome *biome = bmgr->biomes[biomemap[index]];
 486
 487                 //////////////////// First, add top nodes below the ridge
 488                 s16 y = ridge_heightmap[index];
 489
 490                 // This cutoff is good enough, but not perfect.
 491                 // It will cut off potentially placed top nodes at chunk boundaries
 492                 if (y < node_min.Y)
 493                         continue;
 494                 if (y > node_max.Y) {
 495                         y = node_max.Y; // Let's see if we can still go downward anyway
 496                         u32 vi = vm->m_area.index(x, y, z);
 497                         content_t c = vm->m_data[vi].getContent();
 498                         if (ndef->get(c).walkable)
 499                                 continue;
 500                 }
 501
 502                 // N.B.  It is necessary to search downward since ridge_heightmap[i]
 503                 // might not be the actual height, just the lowest part in the chunk
 504                 // where a ridge had been carved
 505                 u32 i = vm->m_area.index(x, y, z);
 506                 for (; y >= node_min.Y; y--) {
 507                         content_t c = vm->m_data[i].getContent();
 508                         if (ndef->get(c).walkable)
 509                                 break;
 510                         vm->m_area.add_y(em, i, -1);
 511                 }
 512
 513                 if (y != node_min.Y - 1 && y >= water_level) {
 514                         ridge_heightmap[index] = y; //update ridgeheight
 515                         ntopnodes = biome->top_depth;
 516                         for (; y <= node_max.Y && ntopnodes; y++) {
 517                                 ntopnodes--;
 518                                 vm->m_data[i] = MapNode(biome->c_top);
 519                                 vm->m_area.add_y(em, i, 1);
 520                         }
 521                         // If dirt, grow grass on it.
 522                         if (y > water_level - 10 &&
 523                                 vm->m_data[i].getContent() == CONTENT_AIR) {
 524                                 vm->m_area.add_y(em, i, -1);
 525                                 if (vm->m_data[i].getContent() == c_dirt)
 526                                         vm->m_data[i] = MapNode(c_dirt_with_grass);
 527                         }
 528                 }
 529
 530                 //////////////////// Now, add top nodes on top of the ridge
 531                 y = heightmap[index];
 532                 if (y > node_max.Y) {
 533                         y = node_max.Y; // Let's see if we can still go downward anyway
 534                         u32 vi = vm->m_area.index(x, y, z);
 535                         content_t c = vm->m_data[vi].getContent();
 536                         if (ndef->get(c).walkable)
 537                                 continue;
 538                 }
 539
 540                 i = vm->m_area.index(x, y, z);
 541                 for (; y >= node_min.Y; y--) {
 542                         content_t c = vm->m_data[i].getContent();
 543                         if (ndef->get(c).walkable)
 544                                 break;
 545                         vm->m_area.add_y(em, i, -1);
 546                 }
 547
 548                 if (y != node_min.Y - 1) {
 549                         ntopnodes = biome->top_depth;
 550                         // Let's see if we've already added it...
 551                         if (y == ridge_heightmap[index] + ntopnodes - 1)
 552                                 continue;
 553
 554                         for (; y <= node_max.Y && ntopnodes; y++) {
 555                                 ntopnodes--;
 556                                 vm->m_data[i] = MapNode(biome->c_top);
 557                                 vm->m_area.add_y(em, i, 1);
 558                         }
 559                         // If dirt, grow grass on it.
 560                         if (y > water_level - 10 &&
 561                                 vm->m_data[i].getContent() == CONTENT_AIR) {
 562                                 vm->m_area.add_y(em, i, -1);
 563                                 if (vm->m_data[i].getContent() == c_dirt)
 564                                         vm->m_data[i] = MapNode(c_dirt_with_grass);
 565                         }
 566                 }
 567         }
 568 }
 569 #endif