src/mapgen/mapgen_carpathian.cpp

   1 /*
   2 Minetest
   3 Copyright (C) 2017-2019 vlapsley, Vaughan Lapsley <vlapsley@gmail.com>
   4 Copyright (C) 2017-2019 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 <cmath>
  23 #include "mapgen.h"
  24 #include "voxel.h"
  25 #include "noise.h"
  26 #include "mapblock.h"
  27 #include "mapnode.h"
  28 #include "map.h"
  29 #include "content_sao.h"
  30 #include "nodedef.h"
  31 #include "voxelalgorithms.h"
  32 //#include "profiler.h" // For TimeTaker
  33 #include "settings.h" // For g_settings
  34 #include "emerge.h"
  35 #include "dungeongen.h"
  36 #include "cavegen.h"
  37 #include "mg_biome.h"
  38 #include "mg_ore.h"
  39 #include "mg_decoration.h"
  40 #include "mapgen_carpathian.h"
  41
  42
  43 FlagDesc flagdesc_mapgen_carpathian[] = {
  44         {"caverns", MGCARPATHIAN_CAVERNS},
  45         {"rivers",  MGCARPATHIAN_RIVERS},
  46         {NULL,      0}
  47 };
  48
  49
  50 ///////////////////////////////////////////////////////////////////////////////
  51
  52
  53 MapgenCarpathian::MapgenCarpathian(MapgenCarpathianParams *params, EmergeManager *emerge)
  54         : MapgenBasic(MAPGEN_CARPATHIAN, params, emerge)
  55 {
  56         base_level       = params->base_level;
  57         river_width      = params->river_width;
  58         river_depth      = params->river_depth;
  59         valley_width     = params->valley_width;
  60
  61         spflags          = params->spflags;
  62         cave_width       = params->cave_width;
  63         large_cave_depth = params->large_cave_depth;
  64         lava_depth       = params->lava_depth;
  65         cavern_limit     = params->cavern_limit;
  66         cavern_taper     = params->cavern_taper;
  67         cavern_threshold = params->cavern_threshold;
  68         dungeon_ymin     = params->dungeon_ymin;
  69         dungeon_ymax     = params->dungeon_ymax;
  70
  71         grad_wl = 1 - water_level;
  72
  73         //// 2D Terrain noise
  74         noise_filler_depth  = new Noise(&params->np_filler_depth,  seed, csize.X, csize.Z);
  75         noise_height1       = new Noise(&params->np_height1,       seed, csize.X, csize.Z);
  76         noise_height2       = new Noise(&params->np_height2,       seed, csize.X, csize.Z);
  77         noise_height3       = new Noise(&params->np_height3,       seed, csize.X, csize.Z);
  78         noise_height4       = new Noise(&params->np_height4,       seed, csize.X, csize.Z);
  79         noise_hills_terrain = new Noise(&params->np_hills_terrain, seed, csize.X, csize.Z);
  80         noise_ridge_terrain = new Noise(&params->np_ridge_terrain, seed, csize.X, csize.Z);
  81         noise_step_terrain  = new Noise(&params->np_step_terrain,  seed, csize.X, csize.Z);
  82         noise_hills         = new Noise(&params->np_hills,         seed, csize.X, csize.Z);
  83         noise_ridge_mnt     = new Noise(&params->np_ridge_mnt,     seed, csize.X, csize.Z);
  84         noise_step_mnt      = new Noise(&params->np_step_mnt,      seed, csize.X, csize.Z);
  85         if (spflags & MGCARPATHIAN_RIVERS)
  86                 noise_rivers    = new Noise(&params->np_rivers,        seed, csize.X, csize.Z);
  87
  88         //// 3D terrain noise
  89         // 1 up 1 down overgeneration
  90         noise_mnt_var = new Noise(&params->np_mnt_var, seed, csize.X, csize.Y + 2, csize.Z);
  91
  92         //// Cave noise
  93         MapgenBasic::np_cave1  = params->np_cave1;
  94         MapgenBasic::np_cave2  = params->np_cave2;
  95         MapgenBasic::np_cavern = params->np_cavern;
  96         MapgenBasic::np_dungeons = params->np_dungeons;
  97 }
  98
  99
 100 MapgenCarpathian::~MapgenCarpathian()
 101 {
 102         delete noise_filler_depth;
 103         delete noise_height1;
 104         delete noise_height2;
 105         delete noise_height3;
 106         delete noise_height4;
 107         delete noise_hills_terrain;
 108         delete noise_ridge_terrain;
 109         delete noise_step_terrain;
 110         delete noise_hills;
 111         delete noise_ridge_mnt;
 112         delete noise_step_mnt;
 113         if (spflags & MGCARPATHIAN_RIVERS)
 114                 delete noise_rivers;
 115
 116         delete noise_mnt_var;
 117 }
 118
 119
 120 MapgenCarpathianParams::MapgenCarpathianParams():
 121         np_filler_depth  (0,   1,   v3f(128,  128,  128),  261,   3, 0.7,  2.0),
 122         np_height1       (0,   5,   v3f(251,  251,  251),  9613,  5, 0.5,  2.0),
 123         np_height2       (0,   5,   v3f(383,  383,  383),  1949,  5, 0.5,  2.0),
 124         np_height3       (0,   5,   v3f(509,  509,  509),  3211,  5, 0.5,  2.0),
 125         np_height4       (0,   5,   v3f(631,  631,  631),  1583,  5, 0.5,  2.0),
 126         np_hills_terrain (1,   1,   v3f(1301, 1301, 1301), 1692,  5, 0.5,  2.0),
 127         np_ridge_terrain (1,   1,   v3f(1889, 1889, 1889), 3568,  5, 0.5,  2.0),
 128         np_step_terrain  (1,   1,   v3f(1889, 1889, 1889), 4157,  5, 0.5,  2.0),
 129         np_hills         (0,   3,   v3f(257,  257,  257),  6604,  6, 0.5,  2.0),
 130         np_ridge_mnt     (0,   12,  v3f(743,  743,  743),  5520,  6, 0.7,  2.0),
 131         np_step_mnt      (0,   8,   v3f(509,  509,  509),  2590,  6, 0.6,  2.0),
 132         np_rivers        (0,   1,   v3f(1000, 1000, 1000), 85039, 5, 0.6,  2.0),
 133         np_mnt_var       (0,   1,   v3f(499,  499,  499),  2490,  5, 0.55, 2.0),
 134         np_cave1         (0,   12,  v3f(61,   61,   61),   52534, 3, 0.5,  2.0),
 135         np_cave2         (0,   12,  v3f(67,   67,   67),   10325, 3, 0.5,  2.0),
 136         np_cavern        (0,   1,   v3f(384,  128,  384),  723,   5, 0.63, 2.0),
 137         np_dungeons      (0.9, 0.5, v3f(500,  500,  500),  0,     2, 0.8,  2.0)
 138 {
 139 }
 140
 141
 142 void MapgenCarpathianParams::readParams(const Settings *settings)
 143 {
 144         settings->getFlagStrNoEx("mgcarpathian_spflags", spflags, flagdesc_mapgen_carpathian);
 145
 146         settings->getFloatNoEx("mgcarpathian_base_level",   base_level);
 147         settings->getFloatNoEx("mgcarpathian_river_width",  river_width);
 148         settings->getFloatNoEx("mgcarpathian_river_depth",  river_depth);
 149         settings->getFloatNoEx("mgcarpathian_valley_width", valley_width);
 150
 151         settings->getFloatNoEx("mgcarpathian_cave_width",       cave_width);
 152         settings->getS16NoEx("mgcarpathian_large_cave_depth",   large_cave_depth);
 153         settings->getS16NoEx("mgcarpathian_lava_depth",         lava_depth);
 154         settings->getS16NoEx("mgcarpathian_cavern_limit",       cavern_limit);
 155         settings->getS16NoEx("mgcarpathian_cavern_taper",       cavern_taper);
 156         settings->getFloatNoEx("mgcarpathian_cavern_threshold", cavern_threshold);
 157         settings->getS16NoEx("mgcarpathian_dungeon_ymin",       dungeon_ymin);
 158         settings->getS16NoEx("mgcarpathian_dungeon_ymax",       dungeon_ymax);
 159
 160         settings->getNoiseParams("mgcarpathian_np_filler_depth",  np_filler_depth);
 161         settings->getNoiseParams("mgcarpathian_np_height1",       np_height1);
 162         settings->getNoiseParams("mgcarpathian_np_height2",       np_height2);
 163         settings->getNoiseParams("mgcarpathian_np_height3",       np_height3);
 164         settings->getNoiseParams("mgcarpathian_np_height4",       np_height4);
 165         settings->getNoiseParams("mgcarpathian_np_hills_terrain", np_hills_terrain);
 166         settings->getNoiseParams("mgcarpathian_np_ridge_terrain", np_ridge_terrain);
 167         settings->getNoiseParams("mgcarpathian_np_step_terrain",  np_step_terrain);
 168         settings->getNoiseParams("mgcarpathian_np_hills",         np_hills);
 169         settings->getNoiseParams("mgcarpathian_np_ridge_mnt",     np_ridge_mnt);
 170         settings->getNoiseParams("mgcarpathian_np_step_mnt",      np_step_mnt);
 171         settings->getNoiseParams("mgcarpathian_np_rivers",        np_rivers);
 172         settings->getNoiseParams("mgcarpathian_np_mnt_var",       np_mnt_var);
 173         settings->getNoiseParams("mgcarpathian_np_cave1",         np_cave1);
 174         settings->getNoiseParams("mgcarpathian_np_cave2",         np_cave2);
 175         settings->getNoiseParams("mgcarpathian_np_cavern",        np_cavern);
 176         settings->getNoiseParams("mgcarpathian_np_dungeons",      np_dungeons);
 177 }
 178
 179
 180 void MapgenCarpathianParams::writeParams(Settings *settings) const
 181 {
 182         settings->setFlagStr("mgcarpathian_spflags", spflags, flagdesc_mapgen_carpathian, U32_MAX);
 183
 184         settings->setFloat("mgcarpathian_base_level",   base_level);
 185         settings->setFloat("mgcarpathian_river_width",  river_width);
 186         settings->setFloat("mgcarpathian_river_depth",  river_depth);
 187         settings->setFloat("mgcarpathian_valley_width", valley_width);
 188
 189         settings->setFloat("mgcarpathian_cave_width",       cave_width);
 190         settings->setS16("mgcarpathian_large_cave_depth",   large_cave_depth);
 191         settings->setS16("mgcarpathian_lava_depth",         lava_depth);
 192         settings->setS16("mgcarpathian_cavern_limit",       cavern_limit);
 193         settings->setS16("mgcarpathian_cavern_taper",       cavern_taper);
 194         settings->setFloat("mgcarpathian_cavern_threshold", cavern_threshold);
 195         settings->setS16("mgcarpathian_dungeon_ymin",       dungeon_ymin);
 196         settings->setS16("mgcarpathian_dungeon_ymax",       dungeon_ymax);
 197
 198         settings->setNoiseParams("mgcarpathian_np_filler_depth",  np_filler_depth);
 199         settings->setNoiseParams("mgcarpathian_np_height1",       np_height1);
 200         settings->setNoiseParams("mgcarpathian_np_height2",       np_height2);
 201         settings->setNoiseParams("mgcarpathian_np_height3",       np_height3);
 202         settings->setNoiseParams("mgcarpathian_np_height4",       np_height4);
 203         settings->setNoiseParams("mgcarpathian_np_hills_terrain", np_hills_terrain);
 204         settings->setNoiseParams("mgcarpathian_np_ridge_terrain", np_ridge_terrain);
 205         settings->setNoiseParams("mgcarpathian_np_step_terrain",  np_step_terrain);
 206         settings->setNoiseParams("mgcarpathian_np_hills",         np_hills);
 207         settings->setNoiseParams("mgcarpathian_np_ridge_mnt",     np_ridge_mnt);
 208         settings->setNoiseParams("mgcarpathian_np_step_mnt",      np_step_mnt);
 209         settings->setNoiseParams("mgcarpathian_np_rivers",        np_rivers);
 210         settings->setNoiseParams("mgcarpathian_np_mnt_var",       np_mnt_var);
 211         settings->setNoiseParams("mgcarpathian_np_cave1",         np_cave1);
 212         settings->setNoiseParams("mgcarpathian_np_cave2",         np_cave2);
 213         settings->setNoiseParams("mgcarpathian_np_cavern",        np_cavern);
 214         settings->setNoiseParams("mgcarpathian_np_dungeons",      np_dungeons);
 215 }
 216
 217
 218 ////////////////////////////////////////////////////////////////////////////////
 219
 220
 221 // Lerp function
 222 inline float MapgenCarpathian::getLerp(float noise1, float noise2, float mod)
 223 {
 224         return noise1 + mod * (noise2 - noise1);
 225 }
 226
 227 // Steps function
 228 float MapgenCarpathian::getSteps(float noise)
 229 {
 230         float w = 0.5f;
 231         float k = std::floor(noise / w);
 232         float f = (noise - k * w) / w;
 233         float s = std::fmin(2.f * f, 1.f);
 234         return (k + s) * w;
 235 }
 236
 237
 238 ////////////////////////////////////////////////////////////////////////////////
 239
 240
 241 void MapgenCarpathian::makeChunk(BlockMakeData *data)
 242 {
 243         // Pre-conditions
 244         assert(data->vmanip);
 245         assert(data->nodedef);
 246         assert(data->blockpos_requested.X >= data->blockpos_min.X &&
 247                         data->blockpos_requested.Y >= data->blockpos_min.Y &&
 248                         data->blockpos_requested.Z >= data->blockpos_min.Z);
 249         assert(data->blockpos_requested.X <= data->blockpos_max.X &&
 250                         data->blockpos_requested.Y <= data->blockpos_max.Y &&
 251                         data->blockpos_requested.Z <= data->blockpos_max.Z);
 252
 253         this->generating = true;
 254         this->vm = data->vmanip;
 255         this->ndef = data->nodedef;
 256
 257         v3s16 blockpos_min = data->blockpos_min;
 258         v3s16 blockpos_max = data->blockpos_max;
 259         node_min = blockpos_min * MAP_BLOCKSIZE;
 260         node_max = (blockpos_max + v3s16(1, 1, 1)) * MAP_BLOCKSIZE - v3s16(1, 1, 1);
 261         full_node_min = (blockpos_min - 1) * MAP_BLOCKSIZE;
 262         full_node_max = (blockpos_max + 2) * MAP_BLOCKSIZE - v3s16(1, 1, 1);
 263
 264         // Create a block-specific seed
 265         blockseed = getBlockSeed2(full_node_min, seed);
 266
 267         // Generate terrain
 268         s16 stone_surface_max_y = generateTerrain();
 269
 270         // Create heightmap
 271         updateHeightmap(node_min, node_max);
 272
 273         // Init biome generator, place biome-specific nodes, and build biomemap
 274         if (flags & MG_BIOMES) {
 275                 biomegen->calcBiomeNoise(node_min);
 276                 generateBiomes();
 277         }
 278
 279         // Generate tunnels, caverns and large randomwalk caves
 280         if (flags & MG_CAVES) {
 281                 // Generate tunnels first as caverns confuse them
 282                 generateCavesNoiseIntersection(stone_surface_max_y);
 283
 284                 // Generate caverns
 285                 bool near_cavern = false;
 286                 if (spflags & MGCARPATHIAN_CAVERNS)
 287                         near_cavern = generateCavernsNoise(stone_surface_max_y);
 288
 289                 // Generate large randomwalk caves
 290                 if (near_cavern)
 291                         // Disable large randomwalk caves in this mapchunk by setting
 292                         // 'large cave depth' to world base. Avoids excessive liquid in
 293                         // large caverns and floating blobs of overgenerated liquid.
 294                         generateCavesRandomWalk(stone_surface_max_y,
 295                                 -MAX_MAP_GENERATION_LIMIT);
 296                 else
 297                         generateCavesRandomWalk(stone_surface_max_y, large_cave_depth);
 298         }
 299
 300         // Generate the registered ores
 301         m_emerge->oremgr->placeAllOres(this, blockseed, node_min, node_max);
 302
 303         // Generate dungeons
 304         if ((flags & MG_DUNGEONS) && full_node_min.Y >= dungeon_ymin &&
 305                         full_node_max.Y <= dungeon_ymax)
 306                 generateDungeons(stone_surface_max_y);
 307
 308         // Generate the registered decorations
 309         if (flags & MG_DECORATIONS)
 310                 m_emerge->decomgr->placeAllDecos(this, blockseed, node_min, node_max);
 311
 312         // Sprinkle some dust on top after everything else was generated
 313         if (flags & MG_BIOMES)
 314                 dustTopNodes();
 315
 316         // Update liquids
 317         updateLiquid(&data->transforming_liquid, full_node_min, full_node_max);
 318
 319         // Calculate lighting
 320         if (flags & MG_LIGHT) {
 321                 calcLighting(node_min - v3s16(0, 1, 0), node_max + v3s16(0, 1, 0),
 322                                 full_node_min, full_node_max);
 323         }
 324
 325         this->generating = false;
 326 }
 327
 328
 329 ////////////////////////////////////////////////////////////////////////////////
 330
 331
 332 int MapgenCarpathian::getSpawnLevelAtPoint(v2s16 p)
 333 {
 334         // If rivers are enabled, first check if in a river channel
 335         if (spflags & MGCARPATHIAN_RIVERS) {
 336                 float river = std::fabs(NoisePerlin2D(&noise_rivers->np, p.X, p.Y, seed)) -
 337                         river_width;
 338                 if (river < 0.0f)
 339                         return MAX_MAP_GENERATION_LIMIT; // Unsuitable spawn point
 340         }
 341
 342         float height1 = NoisePerlin2D(&noise_height1->np, p.X, p.Y, seed);
 343         float height2 = NoisePerlin2D(&noise_height2->np, p.X, p.Y, seed);
 344         float height3 = NoisePerlin2D(&noise_height3->np, p.X, p.Y, seed);
 345         float height4 = NoisePerlin2D(&noise_height4->np, p.X, p.Y, seed);
 346
 347         float hterabs = std::fabs(NoisePerlin2D(&noise_hills_terrain->np, p.X, p.Y, seed));
 348         float n_hills = NoisePerlin2D(&noise_hills->np, p.X, p.Y, seed);
 349         float hill_mnt = hterabs * hterabs * hterabs * n_hills * n_hills;
 350
 351         float rterabs = std::fabs(NoisePerlin2D(&noise_ridge_terrain->np, p.X, p.Y, seed));
 352         float n_ridge_mnt = NoisePerlin2D(&noise_ridge_mnt->np, p.X, p.Y, seed);
 353         float ridge_mnt = rterabs * rterabs * rterabs * (1.0f - std::fabs(n_ridge_mnt));
 354
 355         float sterabs = std::fabs(NoisePerlin2D(&noise_step_terrain->np, p.X, p.Y, seed));
 356         float n_step_mnt = NoisePerlin2D(&noise_step_mnt->np, p.X, p.Y, seed);
 357         float step_mnt = sterabs * sterabs * sterabs * getSteps(n_step_mnt);
 358
 359         float valley = 1.0f;
 360         float river = 0.0f;
 361
 362         if ((spflags & MGCARPATHIAN_RIVERS) && node_max.Y >= water_level - 16) {
 363                 river = std::fabs(NoisePerlin2D(&noise_rivers->np, p.X, p.Y, seed)) - river_width;
 364                 if (river <= valley_width) {
 365                         // Within river valley
 366                         if (river < 0.0f) {
 367                                 // River channel
 368                                 valley = river;
 369                         } else {
 370                                 // Valley slopes.
 371                                 // 0 at river edge, 1 at valley edge.
 372                                 float riversc = river / valley_width;
 373                                 // Smoothstep
 374                                 valley = riversc * riversc * (3.0f - 2.0f * riversc);
 375                         }
 376                 }
 377         }
 378
 379         bool solid_below = false;
 380         u8 cons_non_solid = 0; // consecutive non-solid nodes
 381
 382         for (s16 y = water_level; y <= water_level + 32; y++) {
 383                 float mnt_var = NoisePerlin3D(&noise_mnt_var->np, p.X, y, p.Y, seed);
 384                 float hill1 = getLerp(height1, height2, mnt_var);
 385                 float hill2 = getLerp(height3, height4, mnt_var);
 386                 float hill3 = getLerp(height3, height2, mnt_var);
 387                 float hill4 = getLerp(height1, height4, mnt_var);
 388
 389                 float hilliness = std::fmax(std::fmin(hill1, hill2), std::fmin(hill3, hill4));
 390                 float hills = hill_mnt * hilliness;
 391                 float ridged_mountains = ridge_mnt * hilliness;
 392                 float step_mountains = step_mnt * hilliness;
 393
 394                 s32 grad = 1 - y;
 395
 396                 float mountains = hills + ridged_mountains + step_mountains;
 397                 float surface_level = base_level + mountains + grad;
 398
 399                 if ((spflags & MGCARPATHIAN_RIVERS) && river <= valley_width) {
 400                         if (valley < 0.0f) {
 401                                 // River channel
 402                                 surface_level = std::fmin(surface_level,
 403                                         water_level - std::sqrt(-valley) * river_depth);
 404                         } else if (surface_level > water_level) {
 405                                 // Valley slopes
 406                                 surface_level = water_level + (surface_level - water_level) * valley;
 407                         }
 408                 }
 409
 410                 if (y < surface_level) { //TODO '<=' fix from generateTerrain()
 411                         // solid node
 412                         solid_below = true;
 413                         cons_non_solid = 0;
 414                 } else {
 415                         // non-solid node
 416                         cons_non_solid++;
 417                         if (cons_non_solid == 3 && solid_below)
 418                                 return y - 1;
 419                 }
 420         }
 421
 422         return MAX_MAP_GENERATION_LIMIT; // No suitable spawn point found
 423 }
 424
 425
 426 ////////////////////////////////////////////////////////////////////////////////
 427
 428
 429 int MapgenCarpathian::generateTerrain()
 430 {
 431         MapNode mn_air(CONTENT_AIR);
 432         MapNode mn_stone(c_stone);
 433         MapNode mn_water(c_water_source);
 434
 435         // Calculate noise for terrain generation
 436         noise_height1->perlinMap2D(node_min.X, node_min.Z);
 437         noise_height2->perlinMap2D(node_min.X, node_min.Z);
 438         noise_height3->perlinMap2D(node_min.X, node_min.Z);
 439         noise_height4->perlinMap2D(node_min.X, node_min.Z);
 440         noise_hills_terrain->perlinMap2D(node_min.X, node_min.Z);
 441         noise_ridge_terrain->perlinMap2D(node_min.X, node_min.Z);
 442         noise_step_terrain->perlinMap2D(node_min.X, node_min.Z);
 443         noise_hills->perlinMap2D(node_min.X, node_min.Z);
 444         noise_ridge_mnt->perlinMap2D(node_min.X, node_min.Z);
 445         noise_step_mnt->perlinMap2D(node_min.X, node_min.Z);
 446         noise_mnt_var->perlinMap3D(node_min.X, node_min.Y - 1, node_min.Z);
 447
 448         if (spflags & MGCARPATHIAN_RIVERS)
 449                 noise_rivers->perlinMap2D(node_min.X, node_min.Z);
 450
 451         //// Place nodes
 452         const v3s16 &em = vm->m_area.getExtent();
 453         s16 stone_surface_max_y = -MAX_MAP_GENERATION_LIMIT;
 454         u32 index2d = 0;
 455
 456         for (s16 z = node_min.Z; z <= node_max.Z; z++)
 457         for (s16 x = node_min.X; x <= node_max.X; x++, index2d++) {
 458                 // Hill/Mountain height (hilliness)
 459                 float height1 = noise_height1->result[index2d];
 460                 float height2 = noise_height2->result[index2d];
 461                 float height3 = noise_height3->result[index2d];
 462                 float height4 = noise_height4->result[index2d];
 463
 464                 // Rolling hills
 465                 float hterabs = std::fabs(noise_hills_terrain->result[index2d]);
 466                 float n_hills = noise_hills->result[index2d];
 467                 float hill_mnt = hterabs * hterabs * hterabs * n_hills * n_hills;
 468
 469                 // Ridged mountains
 470                 float rterabs = std::fabs(noise_ridge_terrain->result[index2d]);
 471                 float n_ridge_mnt = noise_ridge_mnt->result[index2d];
 472                 float ridge_mnt = rterabs * rterabs * rterabs *
 473                         (1.0f - std::fabs(n_ridge_mnt));
 474
 475                 // Step (terraced) mountains
 476                 float sterabs = std::fabs(noise_step_terrain->result[index2d]);
 477                 float n_step_mnt = noise_step_mnt->result[index2d];
 478                 float step_mnt = sterabs * sterabs * sterabs * getSteps(n_step_mnt);
 479
 480                 // Rivers
 481                 float valley = 1.0f;
 482                 float river = 0.0f;
 483
 484                 if ((spflags & MGCARPATHIAN_RIVERS) && node_max.Y >= water_level - 16) {
 485                         river = std::fabs(noise_rivers->result[index2d]) - river_width;
 486                         if (river <= valley_width) {
 487                                 // Within river valley
 488                                 if (river < 0.0f) {
 489                                         // River channel
 490                                         valley = river;
 491                                 } else {
 492                                         // Valley slopes.
 493                                         // 0 at river edge, 1 at valley edge.
 494                                         float riversc = river / valley_width;
 495                                         // Smoothstep
 496                                         valley = riversc * riversc * (3.0f - 2.0f * riversc);
 497                                 }
 498                         }
 499                 }
 500
 501                 // Initialise 3D noise index and voxelmanip index to column base
 502                 u32 index3d = (z - node_min.Z) * zstride_1u1d + (x - node_min.X);
 503                 u32 vi = vm->m_area.index(x, node_min.Y - 1, z);
 504
 505                 for (s16 y = node_min.Y - 1; y <= node_max.Y + 1;
 506                                 y++,
 507                                 index3d += ystride,
 508                                 VoxelArea::add_y(em, vi, 1)) {
 509                         if (vm->m_data[vi].getContent() != CONTENT_IGNORE)
 510                                 continue;
 511
 512                         // Combine height noises and apply 3D variation
 513                         float mnt_var = noise_mnt_var->result[index3d];
 514                         float hill1 = getLerp(height1, height2, mnt_var);
 515                         float hill2 = getLerp(height3, height4, mnt_var);
 516                         float hill3 = getLerp(height3, height2, mnt_var);
 517                         float hill4 = getLerp(height1, height4, mnt_var);
 518
 519                         // 'hilliness' determines whether hills/mountains are
 520                         // small or large
 521                         float hilliness =
 522                                 std::fmax(std::fmin(hill1, hill2), std::fmin(hill3, hill4));
 523                         float hills = hill_mnt * hilliness;
 524                         float ridged_mountains = ridge_mnt * hilliness;
 525                         float step_mountains = step_mnt * hilliness;
 526
 527                         // Gradient & shallow seabed
 528                         s32 grad = (y < water_level) ? grad_wl + (water_level - y) * 3 :
 529                                 1 - y;
 530
 531                         // Final terrain level
 532                         float mountains = hills + ridged_mountains + step_mountains;
 533                         float surface_level = base_level + mountains + grad;
 534
 535                         // Rivers
 536                         if ((spflags & MGCARPATHIAN_RIVERS) && node_max.Y >= water_level - 16 &&
 537                                         river <= valley_width) {
 538                                 if (valley < 0.0f) {
 539                                         // River channel
 540                                         surface_level = std::fmin(surface_level,
 541                                                 water_level - std::sqrt(-valley) * river_depth);
 542                                 } else if (surface_level > water_level) {
 543                                         // Valley slopes
 544                                         surface_level = water_level + (surface_level - water_level) * valley;
 545                                 }
 546                         }
 547
 548                         if (y < surface_level) { //TODO '<='
 549                                 vm->m_data[vi] = mn_stone; // Stone
 550                                 if (y > stone_surface_max_y)
 551                                         stone_surface_max_y = y;
 552                         } else if (y <= water_level) {
 553                                 vm->m_data[vi] = mn_water; // Sea water
 554                         } else {
 555                                 vm->m_data[vi] = mn_air; // Air
 556                         }
 557                 }
 558         }
 559
 560         return stone_surface_max_y;
 561 }