src/mapgen/mapgen_v7.cpp

   1 /*
   2 Minetest
   3 Copyright (C) 2013-2019 kwolekr, Ryan Kwolek <kwolekr@minetest.net>
   4 Copyright (C) 2014-2019 paramat
   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 <cmath>
  24 #include "voxel.h"
  25 #include "noise.h"
  26 #include "mapblock.h"
  27 #include "mapnode.h"
  28 #include "map.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 "mg_biome.h"
  37 #include "mg_ore.h"
  38 #include "mg_decoration.h"
  39 #include "mapgen_v7.h"
  40
  41
  42 FlagDesc flagdesc_mapgen_v7[] = {
  43         {"mountains",   MGV7_MOUNTAINS},
  44         {"ridges",      MGV7_RIDGES},
  45         {"floatlands",  MGV7_FLOATLANDS},
  46         {"caverns",     MGV7_CAVERNS},
  47         {NULL,          0}
  48 };
  49
  50
  51 ////////////////////////////////////////////////////////////////////////////////
  52
  53
  54 MapgenV7::MapgenV7(MapgenV7Params *params, EmergeManager *emerge)
  55         : MapgenBasic(MAPGEN_V7, params, emerge)
  56 {
  57         spflags            = params->spflags;
  58         mount_zero_level   = params->mount_zero_level;
  59
  60         cave_width         = params->cave_width;
  61         large_cave_depth   = params->large_cave_depth;
  62         small_cave_num_min = params->small_cave_num_min;
  63         small_cave_num_max = params->small_cave_num_max;
  64         large_cave_num_min = params->large_cave_num_min;
  65         large_cave_num_max = params->large_cave_num_max;
  66         large_cave_flooded = params->large_cave_flooded;
  67         cavern_limit       = params->cavern_limit;
  68         cavern_taper       = params->cavern_taper;
  69         cavern_threshold   = params->cavern_threshold;
  70         dungeon_ymin       = params->dungeon_ymin;
  71         dungeon_ymax       = params->dungeon_ymax;
  72
  73         // 2D noise
  74         noise_terrain_base =
  75                 new Noise(&params->np_terrain_base,    seed, csize.X, csize.Z);
  76         noise_terrain_alt =
  77                 new Noise(&params->np_terrain_alt,     seed, csize.X, csize.Z);
  78         noise_terrain_persist =
  79                 new Noise(&params->np_terrain_persist, seed, csize.X, csize.Z);
  80         noise_height_select =
  81                 new Noise(&params->np_height_select,   seed, csize.X, csize.Z);
  82         noise_filler_depth =
  83                 new Noise(&params->np_filler_depth,    seed, csize.X, csize.Z);
  84
  85         if (spflags & MGV7_MOUNTAINS) {
  86                 // 2D noise
  87                 noise_mount_height =
  88                         new Noise(&params->np_mount_height, seed, csize.X, csize.Z);
  89                 // 3D noise, 1 up, 1 down overgeneration
  90                 noise_mountain =
  91                         new Noise(&params->np_mountain,     seed, csize.X, csize.Y + 2, csize.Z);
  92         }
  93
  94         if (spflags & MGV7_RIDGES) {
  95                 // 2D noise
  96                 noise_ridge_uwater =
  97                         new Noise(&params->np_ridge_uwater, seed, csize.X, csize.Z);
  98                 // 3D noise, 1 up, 1 down overgeneration
  99                 noise_ridge =
 100                         new Noise(&params->np_ridge,        seed, csize.X, csize.Y + 2, csize.Z);
 101         }
 102
 103         // 3D noise, 1 down overgeneration
 104         MapgenBasic::np_cave1    = params->np_cave1;
 105         MapgenBasic::np_cave2    = params->np_cave2;
 106         MapgenBasic::np_cavern   = params->np_cavern;
 107         // 3D noise
 108         MapgenBasic::np_dungeons = params->np_dungeons;
 109 }
 110
 111
 112 MapgenV7::~MapgenV7()
 113 {
 114         delete noise_terrain_base;
 115         delete noise_terrain_alt;
 116         delete noise_terrain_persist;
 117         delete noise_height_select;
 118         delete noise_filler_depth;
 119
 120         if (spflags & MGV7_MOUNTAINS) {
 121                 delete noise_mount_height;
 122                 delete noise_mountain;
 123         }
 124
 125         if (spflags & MGV7_RIDGES) {
 126                 delete noise_ridge_uwater;
 127                 delete noise_ridge;
 128         }
 129 }
 130
 131
 132 MapgenV7Params::MapgenV7Params():
 133         np_terrain_base      (4.0,   70.0,  v3f(600,  600,  600),  82341, 5, 0.6,  2.0),
 134         np_terrain_alt       (4.0,   25.0,  v3f(600,  600,  600),  5934,  5, 0.6,  2.0),
 135         np_terrain_persist   (0.6,   0.1,   v3f(2000, 2000, 2000), 539,   3, 0.6,  2.0),
 136         np_height_select     (-8.0,  16.0,  v3f(500,  500,  500),  4213,  6, 0.7,  2.0),
 137         np_filler_depth      (0.0,   1.2,   v3f(150,  150,  150),  261,   3, 0.7,  2.0),
 138         np_mount_height      (256.0, 112.0, v3f(1000, 1000, 1000), 72449, 3, 0.6,  2.0),
 139         np_ridge_uwater      (0.0,   1.0,   v3f(1000, 1000, 1000), 85039, 5, 0.6,  2.0),
 140         np_mountain          (-0.6,  1.0,   v3f(250,  350,  250),  5333,  5, 0.63, 2.0),
 141         np_ridge             (0.0,   1.0,   v3f(100,  100,  100),  6467,  4, 0.75, 2.0),
 142         np_cavern            (0.0,   1.0,   v3f(384,  128,  384),  723,   5, 0.63, 2.0),
 143         np_cave1             (0.0,   12.0,  v3f(61,   61,   61),   52534, 3, 0.5,  2.0),
 144         np_cave2             (0.0,   12.0,  v3f(67,   67,   67),   10325, 3, 0.5,  2.0),
 145         np_dungeons          (0.9,   0.5,   v3f(500,  500,  500),  0,     2, 0.8,  2.0)
 146 {
 147 }
 148
 149
 150 void MapgenV7Params::readParams(const Settings *settings)
 151 {
 152         settings->getFlagStrNoEx("mgv7_spflags", spflags, flagdesc_mapgen_v7);
 153         settings->getS16NoEx("mgv7_mount_zero_level",       mount_zero_level);
 154         settings->getFloatNoEx("mgv7_cave_width",           cave_width);
 155         settings->getS16NoEx("mgv7_large_cave_depth",       large_cave_depth);
 156         settings->getU16NoEx("mgv7_small_cave_num_min",     small_cave_num_min);
 157         settings->getU16NoEx("mgv7_small_cave_num_max",     small_cave_num_max);
 158         settings->getU16NoEx("mgv7_large_cave_num_min",     large_cave_num_min);
 159         settings->getU16NoEx("mgv7_large_cave_num_max",     large_cave_num_max);
 160         settings->getFloatNoEx("mgv7_large_cave_flooded",   large_cave_flooded);
 161         settings->getS16NoEx("mgv7_cavern_limit",           cavern_limit);
 162         settings->getS16NoEx("mgv7_cavern_taper",           cavern_taper);
 163         settings->getFloatNoEx("mgv7_cavern_threshold",     cavern_threshold);
 164         settings->getS16NoEx("mgv7_dungeon_ymin",           dungeon_ymin);
 165         settings->getS16NoEx("mgv7_dungeon_ymax",           dungeon_ymax);
 166
 167         settings->getNoiseParams("mgv7_np_terrain_base",    np_terrain_base);
 168         settings->getNoiseParams("mgv7_np_terrain_alt",     np_terrain_alt);
 169         settings->getNoiseParams("mgv7_np_terrain_persist", np_terrain_persist);
 170         settings->getNoiseParams("mgv7_np_height_select",   np_height_select);
 171         settings->getNoiseParams("mgv7_np_filler_depth",    np_filler_depth);
 172         settings->getNoiseParams("mgv7_np_mount_height",    np_mount_height);
 173         settings->getNoiseParams("mgv7_np_ridge_uwater",    np_ridge_uwater);
 174         settings->getNoiseParams("mgv7_np_mountain",        np_mountain);
 175         settings->getNoiseParams("mgv7_np_ridge",           np_ridge);
 176         settings->getNoiseParams("mgv7_np_cavern",          np_cavern);
 177         settings->getNoiseParams("mgv7_np_cave1",           np_cave1);
 178         settings->getNoiseParams("mgv7_np_cave2",           np_cave2);
 179         settings->getNoiseParams("mgv7_np_dungeons",        np_dungeons);
 180 }
 181
 182
 183 void MapgenV7Params::writeParams(Settings *settings) const
 184 {
 185         settings->setFlagStr("mgv7_spflags", spflags, flagdesc_mapgen_v7);
 186         settings->setS16("mgv7_mount_zero_level",           mount_zero_level);
 187         settings->setFloat("mgv7_cave_width",               cave_width);
 188         settings->setS16("mgv7_large_cave_depth",           large_cave_depth);
 189         settings->setU16("mgv7_small_cave_num_min",         small_cave_num_min);
 190         settings->setU16("mgv7_small_cave_num_max",         small_cave_num_max);
 191         settings->setU16("mgv7_large_cave_num_min",         large_cave_num_min);
 192         settings->setU16("mgv7_large_cave_num_max",         large_cave_num_max);
 193         settings->setFloat("mgv7_large_cave_flooded",       large_cave_flooded);
 194         settings->setS16("mgv7_cavern_limit",               cavern_limit);
 195         settings->setS16("mgv7_cavern_taper",               cavern_taper);
 196         settings->setFloat("mgv7_cavern_threshold",         cavern_threshold);
 197         settings->setS16("mgv7_dungeon_ymin",               dungeon_ymin);
 198         settings->setS16("mgv7_dungeon_ymax",               dungeon_ymax);
 199
 200         settings->setNoiseParams("mgv7_np_terrain_base",    np_terrain_base);
 201         settings->setNoiseParams("mgv7_np_terrain_alt",     np_terrain_alt);
 202         settings->setNoiseParams("mgv7_np_terrain_persist", np_terrain_persist);
 203         settings->setNoiseParams("mgv7_np_height_select",   np_height_select);
 204         settings->setNoiseParams("mgv7_np_filler_depth",    np_filler_depth);
 205         settings->setNoiseParams("mgv7_np_mount_height",    np_mount_height);
 206         settings->setNoiseParams("mgv7_np_ridge_uwater",    np_ridge_uwater);
 207         settings->setNoiseParams("mgv7_np_mountain",        np_mountain);
 208         settings->setNoiseParams("mgv7_np_ridge",           np_ridge);
 209         settings->setNoiseParams("mgv7_np_cavern",          np_cavern);
 210         settings->setNoiseParams("mgv7_np_cave1",           np_cave1);
 211         settings->setNoiseParams("mgv7_np_cave2",           np_cave2);
 212         settings->setNoiseParams("mgv7_np_dungeons",        np_dungeons);
 213 }
 214
 215
 216 void MapgenV7Params::setDefaultSettings(Settings *settings)
 217 {
 218         settings->setDefault("mgv7_spflags", flagdesc_mapgen_v7,
 219                 MGV7_MOUNTAINS | MGV7_RIDGES | MGV7_CAVERNS);
 220 }
 221
 222
 223 ////////////////////////////////////////////////////////////////////////////////
 224
 225
 226 int MapgenV7::getSpawnLevelAtPoint(v2s16 p)
 227 {
 228         // If rivers are enabled, first check if in a river
 229         if (spflags & MGV7_RIDGES) {
 230                 float width = 0.2f;
 231                 float uwatern = NoisePerlin2D(&noise_ridge_uwater->np, p.X, p.Y, seed) *
 232                         2.0f;
 233                 if (std::fabs(uwatern) <= width)
 234                         return MAX_MAP_GENERATION_LIMIT; // Unsuitable spawn point
 235         }
 236
 237         // Terrain noise 'offset' is the average level of that terrain.
 238         // At least 50% of terrain will be below the higher of base and alt terrain
 239         // 'offset's.
 240         // Raising the maximum spawn level above 'water_level + 16' is necessary
 241         // for when terrain 'offset's are set much higher than water_level.
 242         s16 max_spawn_y = std::fmax(std::fmax(noise_terrain_alt->np.offset,
 243                         noise_terrain_base->np.offset),
 244                         water_level + 16);
 245         // Base terrain calculation
 246         s16 y = baseTerrainLevelAtPoint(p.X, p.Y);
 247
 248         // If mountains are disabled, terrain level is base terrain level.
 249         // Avoids mid-air spawn where mountain terrain would have been.
 250         if (!(spflags & MGV7_MOUNTAINS)) {
 251                 if (y < water_level || y > max_spawn_y)
 252                         return MAX_MAP_GENERATION_LIMIT; // Unsuitable spawn point
 253
 254                 // y + 2 because y is surface level and due to biome 'dust'
 255                 return y + 2;
 256         }
 257
 258         // Search upwards for first node without mountain terrain
 259         int iters = 256;
 260         while (iters > 0 && y <= max_spawn_y) {
 261                 if (!getMountainTerrainAtPoint(p.X, y + 1, p.Y)) {
 262                         if (y <= water_level || y > max_spawn_y)
 263                                 return MAX_MAP_GENERATION_LIMIT; // Unsuitable spawn point
 264
 265                         // y + 1 due to biome 'dust'
 266                         return y + 1;
 267                 }
 268                 y++;
 269                 iters--;
 270         }
 271
 272         // Unsuitable spawn point
 273         return MAX_MAP_GENERATION_LIMIT;
 274 }
 275
 276
 277 void MapgenV7::makeChunk(BlockMakeData *data)
 278 {
 279         // Pre-conditions
 280         assert(data->vmanip);
 281         assert(data->nodedef);
 282         assert(data->blockpos_requested.X >= data->blockpos_min.X &&
 283                 data->blockpos_requested.Y >= data->blockpos_min.Y &&
 284                 data->blockpos_requested.Z >= data->blockpos_min.Z);
 285         assert(data->blockpos_requested.X <= data->blockpos_max.X &&
 286                 data->blockpos_requested.Y <= data->blockpos_max.Y &&
 287                 data->blockpos_requested.Z <= data->blockpos_max.Z);
 288
 289         //TimeTaker t("makeChunk");
 290
 291         this->generating = true;
 292         this->vm = data->vmanip;
 293         this->ndef = data->nodedef;
 294
 295         v3s16 blockpos_min = data->blockpos_min;
 296         v3s16 blockpos_max = data->blockpos_max;
 297         node_min = blockpos_min * MAP_BLOCKSIZE;
 298         node_max = (blockpos_max + v3s16(1, 1, 1)) * MAP_BLOCKSIZE - v3s16(1, 1, 1);
 299         full_node_min = (blockpos_min - 1) * MAP_BLOCKSIZE;
 300         full_node_max = (blockpos_max + 2) * MAP_BLOCKSIZE - v3s16(1, 1, 1);
 301
 302         blockseed = getBlockSeed2(full_node_min, seed);
 303
 304         // Generate base and mountain terrain
 305         s16 stone_surface_max_y = generateTerrain();
 306
 307         // Generate rivers
 308         if (spflags & MGV7_RIDGES)
 309                 generateRidgeTerrain();
 310
 311         // Create heightmap
 312         updateHeightmap(node_min, node_max);
 313
 314         // Init biome generator, place biome-specific nodes, and build biomemap
 315         if (flags & MG_BIOMES) {
 316                 biomegen->calcBiomeNoise(node_min);
 317                 generateBiomes();
 318         }
 319
 320         // Generate tunnels, caverns and large randomwalk caves
 321         if (flags & MG_CAVES) {
 322                 // Generate tunnels first as caverns confuse them
 323                 generateCavesNoiseIntersection(stone_surface_max_y);
 324
 325                 // Generate caverns
 326                 bool near_cavern = false;
 327                 if (spflags & MGV7_CAVERNS)
 328                         near_cavern = generateCavernsNoise(stone_surface_max_y);
 329
 330                 // Generate large randomwalk caves
 331                 if (near_cavern)
 332                         // Disable large randomwalk caves in this mapchunk by setting
 333                         // 'large cave depth' to world base. Avoids excessive liquid in
 334                         // large caverns and floating blobs of overgenerated liquid.
 335                         generateCavesRandomWalk(stone_surface_max_y,
 336                                 -MAX_MAP_GENERATION_LIMIT);
 337                 else
 338                         generateCavesRandomWalk(stone_surface_max_y, large_cave_depth);
 339         }
 340
 341         // Generate the registered ores
 342         m_emerge->oremgr->placeAllOres(this, blockseed, node_min, node_max);
 343
 344         // Generate dungeons
 345         if (flags & MG_DUNGEONS)
 346                 generateDungeons(stone_surface_max_y);
 347
 348         // Generate the registered decorations
 349         if (flags & MG_DECORATIONS)
 350                 m_emerge->decomgr->placeAllDecos(this, blockseed, node_min, node_max);
 351
 352         // Sprinkle some dust on top after everything else was generated
 353         if (flags & MG_BIOMES)
 354                 dustTopNodes();
 355
 356         // Update liquids
 357         updateLiquid(&data->transforming_liquid, full_node_min, full_node_max);
 358
 359         // Calculate lighting
 360         // TODO disable in and just below floatlands
 361         bool propagate_shadow = true;
 362
 363         if (flags & MG_LIGHT)
 364                 calcLighting(node_min - v3s16(0, 1, 0), node_max + v3s16(0, 1, 0),
 365                         full_node_min, full_node_max, propagate_shadow);
 366
 367         this->generating = false;
 368
 369         //printf("makeChunk: %lums\n", t.stop());
 370 }
 371
 372
 373 ////////////////////////////////////////////////////////////////////////////////
 374
 375
 376 float MapgenV7::baseTerrainLevelAtPoint(s16 x, s16 z)
 377 {
 378         float hselect = NoisePerlin2D(&noise_height_select->np, x, z, seed);
 379         hselect = rangelim(hselect, 0.0f, 1.0f);
 380
 381         float persist = NoisePerlin2D(&noise_terrain_persist->np, x, z, seed);
 382
 383         noise_terrain_base->np.persist = persist;
 384         float height_base = NoisePerlin2D(&noise_terrain_base->np, x, z, seed);
 385
 386         noise_terrain_alt->np.persist = persist;
 387         float height_alt = NoisePerlin2D(&noise_terrain_alt->np, x, z, seed);
 388
 389         if (height_alt > height_base)
 390                 return height_alt;
 391
 392         return (height_base * hselect) + (height_alt * (1.0f - hselect));
 393 }
 394
 395
 396 float MapgenV7::baseTerrainLevelFromMap(int index)
 397 {
 398         float hselect = rangelim(noise_height_select->result[index], 0.0f, 1.0f);
 399         float height_base = noise_terrain_base->result[index];
 400         float height_alt = noise_terrain_alt->result[index];
 401
 402         if (height_alt > height_base)
 403                 return height_alt;
 404
 405         return (height_base * hselect) + (height_alt * (1.0f - hselect));
 406 }
 407
 408
 409 bool MapgenV7::getMountainTerrainAtPoint(s16 x, s16 y, s16 z)
 410 {
 411         float mnt_h_n =
 412                 std::fmax(NoisePerlin2D(&noise_mount_height->np, x, z, seed), 1.0f);
 413         float density_gradient = -((float)(y - mount_zero_level) / mnt_h_n);
 414         float mnt_n = NoisePerlin3D(&noise_mountain->np, x, y, z, seed);
 415
 416         return mnt_n + density_gradient >= 0.0f;
 417 }
 418
 419
 420 bool MapgenV7::getMountainTerrainFromMap(int idx_xyz, int idx_xz, s16 y)
 421 {
 422         float mounthn = std::fmax(noise_mount_height->result[idx_xz], 1.0f);
 423         float density_gradient = -((float)(y - mount_zero_level) / mounthn);
 424         float mountn = noise_mountain->result[idx_xyz];
 425
 426         return mountn + density_gradient >= 0.0f;
 427 }
 428
 429
 430 int MapgenV7::generateTerrain()
 431 {
 432         MapNode n_air(CONTENT_AIR);
 433         MapNode n_stone(c_stone);
 434         MapNode n_water(c_water_source);
 435
 436         //// Calculate noise for terrain generation
 437         noise_terrain_persist->perlinMap2D(node_min.X, node_min.Z);
 438         float *persistmap = noise_terrain_persist->result;
 439
 440         noise_terrain_base->perlinMap2D(node_min.X, node_min.Z, persistmap);
 441         noise_terrain_alt->perlinMap2D(node_min.X, node_min.Z, persistmap);
 442         noise_height_select->perlinMap2D(node_min.X, node_min.Z);
 443
 444         if (spflags & MGV7_MOUNTAINS) {
 445                 noise_mount_height->perlinMap2D(node_min.X, node_min.Z);
 446                 noise_mountain->perlinMap3D(node_min.X, node_min.Y - 1, node_min.Z);
 447         }
 448
 449         //// Place nodes
 450         const v3s16 &em = vm->m_area.getExtent();
 451         s16 stone_surface_max_y = -MAX_MAP_GENERATION_LIMIT;
 452         u32 index2d = 0;
 453
 454         for (s16 z = node_min.Z; z <= node_max.Z; z++)
 455         for (s16 x = node_min.X; x <= node_max.X; x++, index2d++) {
 456                 s16 surface_y = baseTerrainLevelFromMap(index2d);
 457                 if (surface_y > stone_surface_max_y)
 458                         stone_surface_max_y = surface_y;
 459
 460                 u32 vi = vm->m_area.index(x, node_min.Y - 1, z);
 461                 u32 index3d = (z - node_min.Z) * zstride_1u1d + (x - node_min.X);
 462
 463                 for (s16 y = node_min.Y - 1; y <= node_max.Y + 1;
 464                                 y++,
 465                                 index3d += ystride,
 466                                 VoxelArea::add_y(em, vi, 1)) {
 467                         if (vm->m_data[vi].getContent() != CONTENT_IGNORE)
 468                                 continue;
 469
 470                         if (y <= surface_y) {
 471                                 vm->m_data[vi] = n_stone; // Base terrain
 472                         } else if ((spflags & MGV7_MOUNTAINS) &&
 473                                         getMountainTerrainFromMap(index3d, index2d, y)) {
 474                                 vm->m_data[vi] = n_stone; // Mountain terrain
 475                                 if (y > stone_surface_max_y)
 476                                         stone_surface_max_y = y;
 477                         } else if (y <= water_level) {
 478                                 vm->m_data[vi] = n_water;
 479                         } else {
 480                                 vm->m_data[vi] = n_air;
 481                         }
 482                 }
 483         }
 484
 485         return stone_surface_max_y;
 486 }
 487
 488
 489 void MapgenV7::generateRidgeTerrain()
 490 {
 491         // TODO disable river canyons in floatlands
 492         if (node_max.Y < water_level - 16)
 493                 return;
 494
 495         noise_ridge->perlinMap3D(node_min.X, node_min.Y - 1, node_min.Z);
 496         noise_ridge_uwater->perlinMap2D(node_min.X, node_min.Z);
 497
 498         MapNode n_water(c_water_source);
 499         MapNode n_air(CONTENT_AIR);
 500         u32 index3d = 0;
 501         float width = 0.2f;
 502
 503         for (s16 z = node_min.Z; z <= node_max.Z; z++)
 504         for (s16 y = node_min.Y - 1; y <= node_max.Y + 1; y++) {
 505                 u32 vi = vm->m_area.index(node_min.X, y, z);
 506                 for (s16 x = node_min.X; x <= node_max.X; x++, index3d++, vi++) {
 507                         u32 index2d = (z - node_min.Z) * csize.X + (x - node_min.X);
 508                         float uwatern = noise_ridge_uwater->result[index2d] * 2.0f;
 509                         if (std::fabs(uwatern) > width)
 510                                 continue;
 511                         // Optimises, but also avoids removing nodes placed by mods in
 512                         // 'on-generated', when generating outside mapchunk.
 513                         content_t c = vm->m_data[vi].getContent();
 514                         if (c != c_stone)
 515                                 continue;
 516
 517                         float altitude = y - water_level;
 518                         float height_mod = (altitude + 17.0f) / 2.5f;
 519                         float width_mod = width - std::fabs(uwatern);
 520                         float nridge = noise_ridge->result[index3d] *
 521                                 std::fmax(altitude, 0.0f) / 7.0f;
 522                         if (nridge + width_mod * height_mod < 0.6f)
 523                                 continue;
 524
 525                         vm->m_data[vi] = (y > water_level) ? n_air : n_water;
 526                 }
 527         }
 528 }