src/mapgen_valleys.cpp

   1 /*
   2 Minetest Valleys C
   3 Copyright (C) 2010-2015 kwolekr, Ryan Kwolek <kwolekr@minetest.net>
   4 Copyright (C) 2010-2015 paramat, Matt Gregory
   5 Copyright (C) 2016 Duane Robertson <duane@duanerobertson.com>
   6
   7 Based on Valleys Mapgen by Gael de Sailly
   8  (https://forum.minetest.net/viewtopic.php?f=9&t=11430)
   9 and mapgen_v7, mapgen_flat by kwolekr and paramat.
  10
  11 Licensing changed by permission of Gael de Sailly.
  12
  13 This program is free software; you can redistribute it and/or modify
  14 it under the terms of the GNU Lesser General Public License as published by
  15 the Free Software Foundation; either version 2.1 of the License, or
  16 (at your option) any later version.
  17
  18 This program is distributed in the hope that it will be useful,
  19 but WITHOUT ANY WARRANTY; without even the implied warranty of
  20 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  21 GNU Lesser General Public License for more details.
  22
  23 You should have received a copy of the GNU Lesser General Public License along
  24 with this program; if not, write to the Free Software Foundation, Inc.,
  25 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  26 */
  27
  28 #include "mapgen.h"
  29 #include "voxel.h"
  30 #include "noise.h"
  31 #include "mapblock.h"
  32 #include "mapnode.h"
  33 #include "map.h"
  34 #include "content_sao.h"
  35 #include "nodedef.h"
  36 #include "voxelalgorithms.h"
  37 #include "settings.h" // For g_settings
  38 #include "emerge.h"
  39 #include "dungeongen.h"
  40 #include "treegen.h"
  41 #include "mg_biome.h"
  42 #include "mg_ore.h"
  43 #include "mg_decoration.h"
  44 #include "mapgen_valleys.h"
  45 #include "cavegen.h"
  46
  47
  48 //#undef NDEBUG
  49 //#include "assert.h"
  50
  51 //#include "util/timetaker.h"
  52 //#include "profiler.h"
  53
  54
  55 //static Profiler mapgen_prof;
  56 //Profiler *mapgen_profiler = &mapgen_prof;
  57
  58 static FlagDesc flagdesc_mapgen_valleys[] = {
  59         {"altitude_chill", MGVALLEYS_ALT_CHILL},
  60         {"humid_rivers",   MGVALLEYS_HUMID_RIVERS},
  61         {NULL,             0}
  62 };
  63
  64 ///////////////////////////////////////////////////////////////////////////////
  65
  66
  67 MapgenValleys::MapgenValleys(int mapgenid, MapgenParams *params, EmergeManager *emerge)
  68         : MapgenBasic(mapgenid, params, emerge)
  69 {
  70         this->m_emerge = emerge;
  71         this->bmgr     = emerge->biomemgr;
  72
  73         //// amount of elements to skip for the next index
  74         //// for noise/height/biome maps (not vmanip)
  75         this->ystride = csize.X;
  76         this->zstride = csize.X * (csize.Y + 2);
  77         // 1-down overgeneration
  78         this->zstride_1d = csize.X * (csize.Y + 1);
  79
  80         this->heightmap = new s16[csize.X * csize.Z];
  81
  82         this->map_gen_limit = MYMIN(MAX_MAP_GENERATION_LIMIT,
  83                         g_settings->getU16("map_generation_limit"));
  84
  85         MapgenValleysParams *sp = (MapgenValleysParams *)params->sparams;
  86         BiomeParamsOriginal *bp = (BiomeParamsOriginal *)params->bparams;
  87
  88         this->spflags            = sp->spflags;
  89         this->altitude_chill     = sp->altitude_chill;
  90         this->large_cave_depth   = sp->large_cave_depth;
  91         this->lava_features_lim  = rangelim(sp->lava_features, 0, 10);
  92         this->massive_cave_depth = sp->massive_cave_depth;
  93         this->river_depth_bed    = sp->river_depth + 1.f;
  94         this->river_size_factor  = sp->river_size / 100.f;
  95         this->water_features_lim = rangelim(sp->water_features, 0, 10);
  96         this->cave_width         = sp->cave_width;
  97
  98         //// 2D Terrain noise
  99         noise_filler_depth       = new Noise(&sp->np_filler_depth,       seed, csize.X, csize.Z);
 100         noise_inter_valley_slope = new Noise(&sp->np_inter_valley_slope, seed, csize.X, csize.Z);
 101         noise_rivers             = new Noise(&sp->np_rivers,             seed, csize.X, csize.Z);
 102         noise_terrain_height     = new Noise(&sp->np_terrain_height,     seed, csize.X, csize.Z);
 103         noise_valley_depth       = new Noise(&sp->np_valley_depth,       seed, csize.X, csize.Z);
 104         noise_valley_profile     = new Noise(&sp->np_valley_profile,     seed, csize.X, csize.Z);
 105
 106         //// 3D Terrain noise
 107         // 1-up 1-down overgeneration
 108         noise_inter_valley_fill = new Noise(&sp->np_inter_valley_fill, seed, csize.X, csize.Y + 2, csize.Z);
 109         // 1-down overgeneraion
 110         noise_cave1             = new Noise(&sp->np_cave1,             seed, csize.X, csize.Y + 1, csize.Z);
 111         noise_cave2             = new Noise(&sp->np_cave2,             seed, csize.X, csize.Y + 1, csize.Z);
 112         noise_massive_caves     = new Noise(&sp->np_massive_caves,     seed, csize.X, csize.Y + 1, csize.Z);
 113
 114         //// Initialize biome generator
 115         // NOTE: valleys mapgen can only use BiomeGenOriginal
 116         biomegen = emerge->biomemgr->createBiomeGen(
 117                 BIOMEGEN_ORIGINAL, params->bparams, csize);
 118         biomemap = biomegen->biomemap;
 119         m_bgen = (BiomeGenOriginal *)biomegen;
 120
 121         this->humid_rivers       = (spflags & MGVALLEYS_HUMID_RIVERS);
 122         this->use_altitude_chill = (spflags & MGVALLEYS_ALT_CHILL);
 123         this->humidity_adjust    = bp->np_humidity.offset - 50.f;
 124
 125         // a small chance of overflows if the settings are very high
 126         this->cave_water_max_height = water_level + MYMAX(0, water_features_lim - 4) * 50;
 127         this->lava_max_height       = water_level + MYMAX(0, lava_features_lim - 4) * 50;
 128
 129         tcave_cache = new float[csize.Y + 2];
 130
 131         //// Resolve nodes to be used
 132         c_cobble               = ndef->getId("mapgen_cobble");
 133         c_desert_stone         = ndef->getId("mapgen_desert_stone");
 134         c_dirt                 = ndef->getId("mapgen_dirt");
 135         c_lava_source          = ndef->getId("mapgen_lava_source");
 136         c_mossycobble          = ndef->getId("mapgen_mossycobble");
 137         c_river_water_source   = ndef->getId("mapgen_river_water_source");
 138         c_sand                 = ndef->getId("mapgen_sand");
 139         c_sandstonebrick       = ndef->getId("mapgen_sandstonebrick");
 140         c_sandstone            = ndef->getId("mapgen_sandstone");
 141         c_stair_cobble         = ndef->getId("mapgen_stair_cobble");
 142         c_stair_sandstonebrick = ndef->getId("mapgen_stair_sandstonebrick");
 143         c_stone                = ndef->getId("mapgen_stone");
 144         c_water_source         = ndef->getId("mapgen_water_source");
 145
 146         if (c_mossycobble == CONTENT_IGNORE)
 147                 c_mossycobble = c_cobble;
 148         if (c_river_water_source == CONTENT_IGNORE)
 149                 c_river_water_source = c_water_source;
 150         if (c_sand == CONTENT_IGNORE)
 151                 c_sand = c_stone;
 152         if (c_sandstonebrick == CONTENT_IGNORE)
 153                 c_sandstonebrick = c_sandstone;
 154         if (c_stair_cobble == CONTENT_IGNORE)
 155                 c_stair_cobble = c_cobble;
 156         if (c_stair_sandstonebrick == CONTENT_IGNORE)
 157                 c_stair_sandstonebrick = c_sandstone;
 158 }
 159
 160
 161 MapgenValleys::~MapgenValleys()
 162 {
 163         delete noise_cave1;
 164         delete noise_cave2;
 165         delete noise_filler_depth;
 166         delete noise_inter_valley_fill;
 167         delete noise_inter_valley_slope;
 168         delete noise_rivers;
 169         delete noise_massive_caves;
 170         delete noise_terrain_height;
 171         delete noise_valley_depth;
 172         delete noise_valley_profile;
 173
 174         delete biomegen;
 175
 176         delete[] heightmap;
 177         delete[] tcave_cache;
 178 }
 179
 180
 181 MapgenValleysParams::MapgenValleysParams()
 182 {
 183         spflags            = MGVALLEYS_HUMID_RIVERS | MGVALLEYS_ALT_CHILL;
 184         altitude_chill     = 90; // The altitude at which temperature drops by 20C.
 185         large_cave_depth   = -33;
 186         lava_features      = 0;  // How often water will occur in caves.
 187         massive_cave_depth = -256;  // highest altitude of massive caves
 188         river_depth        = 4;  // How deep to carve river channels.
 189         river_size         = 5;  // How wide to make rivers.
 190         water_features     = 0;  // How often water will occur in caves.
 191         cave_width         = 0.3;
 192
 193         np_cave1              = NoiseParams(0,     12,   v3f(96,   96,   96),   52534, 4, 0.5,   2.0);
 194         np_cave2              = NoiseParams(0,     12,   v3f(96,   96,   96),   10325, 4, 0.5,   2.0);
 195         np_filler_depth       = NoiseParams(0.f,   1.2f, v3f(256,  256,  256),  1605,  3, 0.5f,  2.f);
 196         np_inter_valley_fill  = NoiseParams(0.f,   1.f,  v3f(256,  512,  256),  1993,  6, 0.8f,  2.f);
 197         np_inter_valley_slope = NoiseParams(0.5f,  0.5f, v3f(128,  128,  128),  746,   1, 1.f,   2.f);
 198         np_rivers             = NoiseParams(0.f,   1.f,  v3f(256,  256,  256),  -6050, 5, 0.6f,  2.f);
 199         np_massive_caves      = NoiseParams(0.f,   1.f,  v3f(768,  256,  768),  59033, 6, 0.63f, 2.f);
 200         np_terrain_height     = NoiseParams(-10.f, 50.f, v3f(1024, 1024, 1024), 5202,  6, 0.4f,  2.f);
 201         np_valley_depth       = NoiseParams(5.f,   4.f,  v3f(512,  512,  512),  -1914, 1, 1.f,   2.f);
 202         np_valley_profile     = NoiseParams(0.6f,  0.5f, v3f(512,  512,  512),  777,   1, 1.f,   2.f);
 203 }
 204
 205
 206 void MapgenValleysParams::readParams(const Settings *settings)
 207 {
 208         settings->getFlagStrNoEx("mgvalleys_spflags",        spflags, flagdesc_mapgen_valleys);
 209         settings->getU16NoEx("mgvalleys_altitude_chill",     altitude_chill);
 210         settings->getS16NoEx("mgvalleys_large_cave_depth",   large_cave_depth);
 211         settings->getU16NoEx("mgvalleys_lava_features",      lava_features);
 212         settings->getS16NoEx("mgvalleys_massive_cave_depth", massive_cave_depth);
 213         settings->getU16NoEx("mgvalleys_river_depth",        river_depth);
 214         settings->getU16NoEx("mgvalleys_river_size",         river_size);
 215         settings->getU16NoEx("mgvalleys_water_features",     water_features);
 216         settings->getFloatNoEx("mgvalleys_cave_width",       cave_width);
 217
 218         settings->getNoiseParams("mgvalleys_np_cave1",              np_cave1);
 219         settings->getNoiseParams("mgvalleys_np_cave2",              np_cave2);
 220         settings->getNoiseParams("mgvalleys_np_filler_depth",       np_filler_depth);
 221         settings->getNoiseParams("mgvalleys_np_inter_valley_fill",  np_inter_valley_fill);
 222         settings->getNoiseParams("mgvalleys_np_inter_valley_slope", np_inter_valley_slope);
 223         settings->getNoiseParams("mgvalleys_np_rivers",             np_rivers);
 224         settings->getNoiseParams("mgvalleys_np_massive_caves",      np_massive_caves);
 225         settings->getNoiseParams("mgvalleys_np_terrain_height",     np_terrain_height);
 226         settings->getNoiseParams("mgvalleys_np_valley_depth",       np_valley_depth);
 227         settings->getNoiseParams("mgvalleys_np_valley_profile",     np_valley_profile);
 228 }
 229
 230
 231 void MapgenValleysParams::writeParams(Settings *settings) const
 232 {
 233         settings->setFlagStr("mgvalleys_spflags",        spflags, flagdesc_mapgen_valleys, U32_MAX);
 234         settings->setU16("mgvalleys_altitude_chill",     altitude_chill);
 235         settings->setS16("mgvalleys_large_cave_depth",   large_cave_depth);
 236         settings->setU16("mgvalleys_lava_features",      lava_features);
 237         settings->setS16("mgvalleys_massive_cave_depth", massive_cave_depth);
 238         settings->setU16("mgvalleys_river_depth",        river_depth);
 239         settings->setU16("mgvalleys_river_size",         river_size);
 240         settings->setU16("mgvalleys_water_features",     water_features);
 241         settings->setFloat("mgvalleys_cave_width",       cave_width);
 242
 243         settings->setNoiseParams("mgvalleys_np_cave1",              np_cave1);
 244         settings->setNoiseParams("mgvalleys_np_cave2",              np_cave2);
 245         settings->setNoiseParams("mgvalleys_np_filler_depth",       np_filler_depth);
 246         settings->setNoiseParams("mgvalleys_np_inter_valley_fill",  np_inter_valley_fill);
 247         settings->setNoiseParams("mgvalleys_np_inter_valley_slope", np_inter_valley_slope);
 248         settings->setNoiseParams("mgvalleys_np_rivers",             np_rivers);
 249         settings->setNoiseParams("mgvalleys_np_massive_caves",      np_massive_caves);
 250         settings->setNoiseParams("mgvalleys_np_terrain_height",     np_terrain_height);
 251         settings->setNoiseParams("mgvalleys_np_valley_depth",       np_valley_depth);
 252         settings->setNoiseParams("mgvalleys_np_valley_profile",     np_valley_profile);
 253 }
 254
 255
 256 ///////////////////////////////////////
 257
 258
 259 void MapgenValleys::makeChunk(BlockMakeData *data)
 260 {
 261         // Pre-conditions
 262         assert(data->vmanip);
 263         assert(data->nodedef);
 264         assert(data->blockpos_requested.X >= data->blockpos_min.X &&
 265                 data->blockpos_requested.Y >= data->blockpos_min.Y &&
 266                 data->blockpos_requested.Z >= data->blockpos_min.Z);
 267         assert(data->blockpos_requested.X <= data->blockpos_max.X &&
 268                 data->blockpos_requested.Y <= data->blockpos_max.Y &&
 269                 data->blockpos_requested.Z <= data->blockpos_max.Z);
 270
 271         this->generating = true;
 272         this->vm = data->vmanip;
 273         this->ndef = data->nodedef;
 274
 275         //TimeTaker t("makeChunk");
 276
 277         v3s16 blockpos_min = data->blockpos_min;
 278         v3s16 blockpos_max = data->blockpos_max;
 279         node_min = blockpos_min * MAP_BLOCKSIZE;
 280         node_max = (blockpos_max + v3s16(1, 1, 1)) * MAP_BLOCKSIZE - v3s16(1, 1, 1);
 281         full_node_min = (blockpos_min - 1) * MAP_BLOCKSIZE;
 282         full_node_max = (blockpos_max + 2) * MAP_BLOCKSIZE - v3s16(1, 1, 1);
 283
 284         blockseed = getBlockSeed2(full_node_min, seed);
 285
 286         // Generate noise maps and base terrain height.
 287         calculateNoise();
 288
 289         // Generate biome noises.  Note this must be executed strictly before
 290         // generateTerrain, because generateTerrain depends on intermediate
 291         // biome-related noises.
 292         biomegen->calcBiomeNoise(node_min);
 293
 294         // Generate base terrain with initial heightmaps
 295         s16 stone_surface_max_y = generateTerrain();
 296
 297         // Build biomemap
 298         biomegen->getBiomes(heightmap);
 299
 300         // Place biome-specific nodes
 301         MgStoneType stone_type = generateBiomes();
 302
 303         // Cave creation.
 304         if (flags & MG_CAVES)
 305                 generateCaves(stone_surface_max_y, large_cave_depth);
 306
 307         // Dungeon creation
 308         if ((flags & MG_DUNGEONS) && node_max.Y < 50 && (stone_surface_max_y >= node_min.Y)) {
 309                 DungeonParams dp;
 310
 311                 dp.np_rarity  = nparams_dungeon_rarity;
 312                 dp.np_density = nparams_dungeon_density;
 313                 dp.np_wetness = nparams_dungeon_wetness;
 314                 dp.c_water    = c_water_source;
 315                 if (stone_type == MGSTONE_STONE) {
 316                         dp.c_cobble = c_cobble;
 317                         dp.c_moss   = c_mossycobble;
 318                         dp.c_stair  = c_stair_cobble;
 319
 320                         dp.diagonal_dirs = false;
 321                         dp.mossratio     = 3.f;
 322                         dp.holesize      = v3s16(1, 2, 1);
 323                         dp.roomsize      = v3s16(0, 0, 0);
 324                         dp.notifytype    = GENNOTIFY_DUNGEON;
 325                 } else if (stone_type == MGSTONE_DESERT_STONE) {
 326                         dp.c_cobble = c_desert_stone;
 327                         dp.c_moss   = c_desert_stone;
 328                         dp.c_stair  = c_desert_stone;
 329
 330                         dp.diagonal_dirs = true;
 331                         dp.mossratio     = 0.f;
 332                         dp.holesize      = v3s16(2, 3, 2);
 333                         dp.roomsize      = v3s16(2, 5, 2);
 334                         dp.notifytype    = GENNOTIFY_TEMPLE;
 335                 } else if (stone_type == MGSTONE_SANDSTONE) {
 336                         dp.c_cobble = c_sandstonebrick;
 337                         dp.c_moss   = c_sandstonebrick;
 338                         dp.c_stair  = c_sandstonebrick;
 339
 340                         dp.diagonal_dirs = false;
 341                         dp.mossratio     = 0.f;
 342                         dp.holesize      = v3s16(2, 2, 2);
 343                         dp.roomsize      = v3s16(2, 0, 2);
 344                         dp.notifytype    = GENNOTIFY_DUNGEON;
 345                 }
 346
 347                 DungeonGen dgen(this, &dp);
 348                 dgen.generate(blockseed, full_node_min, full_node_max);
 349         }
 350
 351         // Generate the registered decorations
 352         if (flags & MG_DECORATIONS)
 353                 m_emerge->decomgr->placeAllDecos(this, blockseed, node_min, node_max);
 354
 355         // Generate the registered ores
 356         m_emerge->oremgr->placeAllOres(this, blockseed, node_min, node_max);
 357
 358         // Sprinkle some dust on top after everything else was generated
 359         dustTopNodes();
 360
 361         //TimeTaker tll("liquid_lighting");
 362
 363         updateLiquid(&data->transforming_liquid, full_node_min, full_node_max);
 364
 365         if (flags & MG_LIGHT)
 366                 calcLighting(
 367                                 node_min - v3s16(0, 1, 0),
 368                                 node_max + v3s16(0, 1, 0),
 369                                 full_node_min,
 370                                 full_node_max);
 371
 372         //mapgen_profiler->avg("liquid_lighting", tll.stop() / 1000.f);
 373         //mapgen_profiler->avg("makeChunk", t.stop() / 1000.f);
 374
 375         this->generating = false;
 376 }
 377
 378
 379 // Populate the noise tables and do most of the
 380 // calculation necessary to determine terrain height.
 381 void MapgenValleys::calculateNoise()
 382 {
 383         //TimeTaker t("calculateNoise", NULL, PRECISION_MICRO);
 384
 385         int x = node_min.X;
 386         int y = node_min.Y - 1;
 387         int z = node_min.Z;
 388
 389         //TimeTaker tcn("actualNoise");
 390
 391         noise_inter_valley_slope->perlinMap2D(x, z);
 392         noise_rivers->perlinMap2D(x, z);
 393         noise_terrain_height->perlinMap2D(x, z);
 394         noise_valley_depth->perlinMap2D(x, z);
 395         noise_valley_profile->perlinMap2D(x, z);
 396
 397         noise_inter_valley_fill->perlinMap3D(x, y, z);
 398
 399         //mapgen_profiler->avg("noisemaps", tcn.stop() / 1000.f);
 400
 401         float heat_offset = 0.f;
 402         float humidity_scale = 1.f;
 403
 404         // Altitude chill tends to reduce the average heat.
 405         if (use_altitude_chill)
 406                 heat_offset = 5.f;
 407
 408         // River humidity tends to increase the humidity range.
 409         if (humid_rivers) {
 410                 humidity_scale = 0.8f;
 411         }
 412
 413         for (s32 index = 0; index < csize.X * csize.Z; index++) {
 414                 m_bgen->heatmap[index] += heat_offset;
 415                 m_bgen->humidmap[index] *= humidity_scale;
 416         }
 417
 418         TerrainNoise tn;
 419
 420         u32 index = 0;
 421         for (tn.z = node_min.Z; tn.z <= node_max.Z; tn.z++)
 422         for (tn.x = node_min.X; tn.x <= node_max.X; tn.x++, index++) {
 423                 // The parameters that we actually need to generate terrain
 424                 //  are passed by address (and the return value).
 425                 tn.terrain_height    = noise_terrain_height->result[index];
 426                 // River noise is replaced with base terrain, which
 427                 // is basically the height of the water table.
 428                 tn.rivers            = &noise_rivers->result[index];
 429                 // Valley depth noise is replaced with the valley
 430                 // number that represents the height of terrain
 431                 // over rivers and is used to determine about
 432                 // how close a river is for humidity calculation.
 433                 tn.valley            = &noise_valley_depth->result[index];
 434                 tn.valley_profile    = noise_valley_profile->result[index];
 435                 // Slope noise is replaced by the calculated slope
 436                 // which is used to get terrain height in the slow
 437                 // method, to create sharper mountains.
 438                 tn.slope             = &noise_inter_valley_slope->result[index];
 439                 tn.inter_valley_fill = noise_inter_valley_fill->result[index];
 440
 441                 // This is the actual terrain height.
 442                 float mount = terrainLevelFromNoise(&tn);
 443                 noise_terrain_height->result[index] = mount;
 444         }
 445 }
 446
 447
 448 // This keeps us from having to maintain two similar sets of
 449 //  complicated code to determine ground level.
 450 float MapgenValleys::terrainLevelFromNoise(TerrainNoise *tn)
 451 {
 452         // The square function changes the behaviour of this noise:
 453         //  very often small, and sometimes very high.
 454         float valley_d = MYSQUARE(*tn->valley);
 455
 456         // valley_d is here because terrain is generally higher where valleys
 457         //  are deep (mountains). base represents the height of the
 458         //  rivers, most of the surface is above.
 459         float base = tn->terrain_height + valley_d;
 460
 461         // "river" represents the distance from the river, in arbitrary units.
 462         float river = fabs(*tn->rivers) - river_size_factor;
 463
 464         // Use the curve of the function 1-exp(-(x/a)^2) to model valleys.
 465         //  Making "a" vary (0 < a <= 1) changes the shape of the valleys.
 466         //  Try it with a geometry software !
 467         //   (here x = "river" and a = valley_profile).
 468         //  "valley" represents the height of the terrain, from the rivers.
 469         {
 470                 float t = river / tn->valley_profile;
 471                 *tn->valley = valley_d * (1.f - exp(- MYSQUARE(t)));
 472         }
 473
 474         // approximate height of the terrain at this point
 475         float mount = base + *tn->valley;
 476
 477         *tn->slope *= *tn->valley;
 478
 479         // Rivers are placed where "river" is negative, so where the original
 480         //  noise value is close to zero.
 481         // Base ground is returned as rivers since it's basically the water table.
 482         *tn->rivers = base;
 483         if (river < 0.f) {
 484                 // Use the the function -sqrt(1-x^2) which models a circle.
 485                 float depth;
 486                 {
 487                         float t = river / river_size_factor + 1;
 488                         depth = (river_depth_bed * sqrt(MYMAX(0, 1.f - MYSQUARE(t))));
 489                 }
 490
 491                 // base - depth : height of the bottom of the river
 492                 // water_level - 3 : don't make rivers below 3 nodes under the surface
 493                 // We use three because that's as low as the swamp biomes go.
 494                 // There is no logical equivalent to this using rangelim.
 495                 mount = MYMIN(MYMAX(base - depth, (float)(water_level - 3)), mount);
 496
 497                 // Slope has no influence on rivers.
 498                 *tn->slope = 0.f;
 499         }
 500
 501         return mount;
 502 }
 503
 504
 505 // This avoids duplicating the code in terrainLevelFromNoise, adding
 506 // only the final step of terrain generation without a noise map.
 507 float MapgenValleys::adjustedTerrainLevelFromNoise(TerrainNoise *tn)
 508 {
 509         float mount = terrainLevelFromNoise(tn);
 510         s16 y_start = myround(mount);
 511
 512         for (s16 y = y_start; y <= y_start + 1000; y++) {
 513                 float fill = NoisePerlin3D(&noise_inter_valley_fill->np, tn->x, y, tn->z, seed);
 514
 515                 if (fill * *tn->slope < y - mount) {
 516                         mount = MYMAX(y - 1, mount);
 517                         break;
 518                 }
 519         }
 520
 521         return mount;
 522 }
 523
 524
 525 int MapgenValleys::getSpawnLevelAtPoint(v2s16 p)
 526 {
 527         // Check to make sure this isn't a request for a location in a river.
 528         float rivers = NoisePerlin2D(&noise_rivers->np, p.X, p.Y, seed);
 529         if (fabs(rivers) < river_size_factor)
 530                 return MAX_MAP_GENERATION_LIMIT;  // Unsuitable spawn point
 531
 532         s16 level_at_point = terrainLevelAtPoint(p.X, p.Y);
 533         if (level_at_point <= water_level ||
 534                         level_at_point > water_level + 32)
 535                 return MAX_MAP_GENERATION_LIMIT;  // Unsuitable spawn point
 536         else
 537                 return level_at_point;
 538 }
 539
 540
 541 float MapgenValleys::terrainLevelAtPoint(s16 x, s16 z)
 542 {
 543         TerrainNoise tn;
 544
 545         float rivers = NoisePerlin2D(&noise_rivers->np, x, z, seed);
 546         float valley = NoisePerlin2D(&noise_valley_depth->np, x, z, seed);
 547         float inter_valley_slope = NoisePerlin2D(&noise_inter_valley_slope->np, x, z, seed);
 548
 549         tn.x                 = x;
 550         tn.z                 = z;
 551         tn.terrain_height    = NoisePerlin2D(&noise_terrain_height->np, x, z, seed);
 552         tn.rivers            = &rivers;
 553         tn.valley            = &valley;
 554         tn.valley_profile    = NoisePerlin2D(&noise_valley_profile->np, x, z, seed);
 555         tn.slope             = &inter_valley_slope;
 556         tn.inter_valley_fill = 0.f;
 557
 558         return adjustedTerrainLevelFromNoise(&tn);
 559 }
 560
 561
 562 int MapgenValleys::generateTerrain()
 563 {
 564         // Raising this reduces the rate of evaporation.
 565         static const float evaporation = 300.f;
 566         // from the lua
 567         static const float humidity_dropoff = 4.f;
 568         // constant to convert altitude chill (compatible with lua) to heat
 569         static const float alt_to_heat = 20.f;
 570         // humidity reduction by altitude
 571         static const float alt_to_humid = 10.f;
 572
 573         MapNode n_air(CONTENT_AIR);
 574         MapNode n_river_water(c_river_water_source);
 575         MapNode n_sand(c_sand);
 576         MapNode n_stone(c_stone);
 577         MapNode n_water(c_water_source);
 578
 579         v3s16 em = vm->m_area.getExtent();
 580         s16 surface_max_y = -MAX_MAP_GENERATION_LIMIT;
 581         u32 index_2d = 0;
 582
 583         for (s16 z = node_min.Z; z <= node_max.Z; z++)
 584         for (s16 x = node_min.X; x <= node_max.X; x++, index_2d++) {
 585                 float river_y = noise_rivers->result[index_2d];
 586                 float surface_y = noise_terrain_height->result[index_2d];
 587                 float slope = noise_inter_valley_slope->result[index_2d];
 588                 float t_heat = m_bgen->heatmap[index_2d];
 589
 590                 heightmap[index_2d] = -MAX_MAP_GENERATION_LIMIT;
 591
 592                 if (surface_y > surface_max_y)
 593                         surface_max_y = ceil(surface_y);
 594
 595                 if (humid_rivers) {
 596                         // Derive heat from (base) altitude. This will be most correct
 597                         // at rivers, since other surface heights may vary below.
 598                         if (use_altitude_chill && (surface_y > 0.f || river_y > 0.f))
 599                                 t_heat -= alt_to_heat * MYMAX(surface_y, river_y) / altitude_chill;
 600
 601                         // If humidity is low or heat is high, lower the water table.
 602                         float delta = m_bgen->humidmap[index_2d] - 50.f;
 603                         if (delta < 0.f) {
 604                                 float t_evap = (t_heat - 32.f) / evaporation;
 605                                 river_y += delta * MYMAX(t_evap, 0.08f);
 606                         }
 607                 }
 608
 609                 u32 index_3d = (z - node_min.Z) * zstride + (x - node_min.X);
 610                 u32 index_data = vm->m_area.index(x, node_min.Y - 1, z);
 611
 612                 // Mapgens concern themselves with stone and water.
 613                 for (s16 y = node_min.Y - 1; y <= node_max.Y + 1; y++) {
 614                         if (vm->m_data[index_data].getContent() == CONTENT_IGNORE) {
 615                                 float fill = noise_inter_valley_fill->result[index_3d];
 616                                 float surface_delta = (float)y - surface_y;
 617                                 bool river = y + 1 < river_y;
 618
 619                                 if (fabs(surface_delta) <= 0.5f && y > water_level && river) {
 620                                         // river bottom
 621                                         vm->m_data[index_data] = n_sand;
 622                                 } else if (slope * fill > surface_delta) {
 623                                         // ground
 624                                         vm->m_data[index_data] = n_stone;
 625                                         if (y > heightmap[index_2d])
 626                                                 heightmap[index_2d] = y;
 627                                         if (y > surface_max_y)
 628                                                 surface_max_y = y;
 629                                 } else if (y <= water_level) {
 630                                         // sea
 631                                         vm->m_data[index_data] = n_water;
 632                                 } else if (river) {
 633                                         // river
 634                                         vm->m_data[index_data] = n_river_water;
 635                                 } else {
 636                                         vm->m_data[index_data] = n_air;
 637                                 }
 638                         }
 639
 640                         vm->m_area.add_y(em, index_data, 1);
 641                         index_3d += ystride;
 642                 }
 643
 644                 // This happens if we're generating a chunk that doesn't
 645                 // contain the terrain surface, in which case, we need
 646                 // to set heightmap to a value outside of the chunk,
 647                 // to avoid confusing lua mods that use heightmap.
 648                 if (heightmap[index_2d] == -MAX_MAP_GENERATION_LIMIT) {
 649                         s16 surface_y_int = myround(surface_y);
 650                         if (surface_y_int > node_max.Y + 1 || surface_y_int < node_min.Y - 1) {
 651                                 // If surface_y is outside the chunk, it's good enough.
 652                                 heightmap[index_2d] = surface_y_int;
 653                         } else {
 654                                 // If the ground is outside of this chunk, but surface_y
 655                                 // is within the chunk, give a value outside.
 656                                 heightmap[index_2d] = node_min.Y - 2;
 657                         }
 658                 }
 659
 660                 if (humid_rivers) {
 661                         // Use base ground (water table) in a riverbed, to
 662                         // avoid an unnatural rise in humidity.
 663                         float t_alt = MYMAX(noise_rivers->result[index_2d], (float)heightmap[index_2d]);
 664                         float humid = m_bgen->humidmap[index_2d];
 665                         float water_depth = (t_alt - river_y) / humidity_dropoff;
 666                         humid *= 1.f + pow(0.5f, MYMAX(water_depth, 1.f));
 667
 668                         // Reduce humidity with altitude (ignoring riverbeds).
 669                         // This is similar to the lua version's seawater adjustment,
 670                         // but doesn't increase the base humidity, which causes
 671                         // problems with the default biomes.
 672                         if (t_alt > 0.f)
 673                                 humid -= alt_to_humid * t_alt / altitude_chill;
 674
 675                         m_bgen->humidmap[index_2d] = humid;
 676                 }
 677
 678                 // Assign the heat adjusted by any changed altitudes.
 679                 // The altitude will change about half the time.
 680                 if (use_altitude_chill) {
 681                         // ground height ignoring riverbeds
 682                         float t_alt = MYMAX(noise_rivers->result[index_2d], (float)heightmap[index_2d]);
 683                         if (humid_rivers && heightmap[index_2d] == (s16)myround(surface_y))
 684                                 // The altitude hasn't changed. Use the first result.
 685                                 m_bgen->heatmap[index_2d] = t_heat;
 686                         else if (t_alt > 0.f)
 687                                 m_bgen->heatmap[index_2d] -= alt_to_heat * t_alt / altitude_chill;
 688                 }
 689         }
 690
 691         return surface_max_y;
 692 }
 693
 694 void MapgenValleys::generateCaves(s16 max_stone_y, s16 large_cave_depth)
 695 {
 696         if (max_stone_y < node_min.Y)
 697                 return;
 698
 699         noise_cave1->perlinMap3D(node_min.X, node_min.Y - 1, node_min.Z);
 700         noise_cave2->perlinMap3D(node_min.X, node_min.Y - 1, node_min.Z);
 701
 702         PseudoRandom ps(blockseed + 72202);
 703
 704         MapNode n_air(CONTENT_AIR);
 705         MapNode n_lava(c_lava_source);
 706         MapNode n_water(c_river_water_source);
 707
 708         v3s16 em = vm->m_area.getExtent();
 709
 710         // Cave blend distance near YMIN, YMAX
 711         const float massive_cave_blend = 128.f;
 712         // noise threshold for massive caves
 713         const float massive_cave_threshold = 0.6f;
 714         // mct: 1 = small rare caves, 0.5 1/3rd ground volume, 0 = 1/2 ground volume.
 715
 716         float yblmin = -map_gen_limit + massive_cave_blend * 1.5f;
 717         float yblmax = massive_cave_depth - massive_cave_blend * 1.5f;
 718         bool made_a_big_one = false;
 719
 720         // Cache the tcave values as they only vary by altitude.
 721         if (node_max.Y <= massive_cave_depth) {
 722                 noise_massive_caves->perlinMap3D(node_min.X, node_min.Y - 1, node_min.Z);
 723
 724                 for (s16 y = node_min.Y - 1; y <= node_max.Y; y++) {
 725                         float tcave = massive_cave_threshold;
 726
 727                         if (y < yblmin) {
 728                                 float t = (yblmin - y) / massive_cave_blend;
 729                                 tcave += MYSQUARE(t);
 730                         } else if (y > yblmax) {
 731                                 float t = (y - yblmax) / massive_cave_blend;
 732                                 tcave += MYSQUARE(t);
 733                         }
 734
 735                         tcave_cache[y - node_min.Y + 1] = tcave;
 736                 }
 737         }
 738
 739         // lava_depth varies between one and ten as you approach
 740         //  the bottom of the world.
 741         s16 lava_depth = ceil((lava_max_height - node_min.Y + 1) * 10.f / map_gen_limit);
 742         // This allows random lava spawns to be less common at the surface.
 743         s16 lava_chance = MYCUBE(lava_features_lim) * lava_depth;
 744         // water_depth varies between ten and one on the way down.
 745         s16 water_depth = ceil((map_gen_limit - abs(node_min.Y) + 1) * 10.f / map_gen_limit);
 746         // This allows random water spawns to be more common at the surface.
 747         s16 water_chance = MYCUBE(water_features_lim) * water_depth;
 748
 749         // Reduce the odds of overflows even further.
 750         if (node_max.Y > water_level) {
 751                 lava_chance /= 3;
 752                 water_chance /= 3;
 753         }
 754
 755         u32 index_2d = 0;
 756         for (s16 z = node_min.Z; z <= node_max.Z; z++)
 757         for (s16 x = node_min.X; x <= node_max.X; x++, index_2d++) {
 758                 Biome *biome = (Biome *)bmgr->getRaw(biomemap[index_2d]);
 759                 bool tunnel_air_above = false;
 760                 bool underground = false;
 761                 u32 index_data = vm->m_area.index(x, node_max.Y, z);
 762                 u32 index_3d = (z - node_min.Z) * zstride_1d + csize.Y * ystride + (x - node_min.X);
 763
 764                 // Dig caves on down loop to check for air above.
 765                 // Don't excavate the overgenerated stone at node_max.Y + 1,
 766                 // this creates a 'roof' over the tunnel, preventing light in
 767                 // tunnels at mapchunk borders when generating mapchunks upwards.
 768                 // This 'roof' is removed when the mapchunk above is generated.
 769                 for (s16 y = node_max.Y; y >= node_min.Y - 1; y--,
 770                                 index_3d -= ystride,
 771                                 vm->m_area.add_y(em, index_data, -1)) {
 772
 773                         float terrain = noise_terrain_height->result[index_2d];
 774
 775                         // Saves some time.
 776                         if (y > terrain + 10)
 777                                 continue;
 778                         else if (y < terrain - 40)
 779                                 underground = true;
 780
 781                         // Dig massive caves.
 782                         if (node_max.Y <= massive_cave_depth
 783                                         && noise_massive_caves->result[index_3d]
 784                                         > tcave_cache[y - node_min.Y + 1]) {
 785                                 vm->m_data[index_data] = n_air;
 786                                 made_a_big_one = true;
 787                                 continue;
 788                         }
 789
 790                         content_t c = vm->m_data[index_data].getContent();
 791                         float d1 = contour(noise_cave1->result[index_3d]);
 792                         float d2 = contour(noise_cave2->result[index_3d]);
 793
 794                         // River water is not set as ground content
 795                         // in the default game. This can produce strange results
 796                         // when a tunnel undercuts a river. However, that's not for
 797                         // the mapgen to correct. Fix it in lua.
 798
 799                         if (d1 * d2 > cave_width && ndef->get(c).is_ground_content) {
 800                                 // in a tunnel
 801                                 vm->m_data[index_data] = n_air;
 802                                 tunnel_air_above = true;
 803                         } else if (c == biome->c_filler || c == biome->c_stone) {
 804                                 if (tunnel_air_above) {
 805                                         // at the tunnel floor
 806                                         s16 sr = ps.range(0, 39);
 807                                         u32 j = index_data;
 808                                         vm->m_area.add_y(em, j, 1);
 809
 810                                         if (sr > terrain - y) {
 811                                                 // Put dirt in tunnels near the surface.
 812                                                 if (underground)
 813                                                         vm->m_data[index_data] = MapNode(biome->c_filler);
 814                                                 else
 815                                                         vm->m_data[index_data] = MapNode(biome->c_top);
 816                                         } else if (sr < 3 && underground) {
 817                                                 sr = abs(ps.next());
 818                                                 if (lava_features_lim > 0 && y <= lava_max_height
 819                                                                 && c == biome->c_stone && sr < lava_chance)
 820                                                         vm->m_data[j] = n_lava;
 821
 822                                                 sr -= lava_chance;
 823
 824                                                 // If sr < 0 then we should have already placed lava --
 825                                                 // don't immediately dump water on it.
 826                                                 if (water_features_lim > 0 && y <= cave_water_max_height
 827                                                                 && sr >= 0 && sr < water_chance)
 828                                                         vm->m_data[j] = n_water;
 829                                         }
 830                                 }
 831
 832                                 tunnel_air_above = false;
 833                                 underground = true;
 834                         } else {
 835                                 tunnel_air_above = false;
 836                         }
 837                 }
 838         }
 839
 840         if (node_max.Y <= large_cave_depth && !made_a_big_one) {
 841                 u32 bruises_count = ps.range(0, 2);
 842                 for (u32 i = 0; i < bruises_count; i++) {
 843                         CavesRandomWalk cave(ndef, &gennotify, seed, water_level,
 844                                 c_water_source, c_lava_source);
 845
 846                         cave.makeCave(vm, node_min, node_max, &ps, true, max_stone_y, heightmap);
 847                 }
 848         }
 849 }