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>
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.
11 Licensing changed by permission of Gael de Sailly.
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.
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.
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.
34 #include "content_sao.h"
36 #include "voxelalgorithms.h"
37 #include "settings.h" // For g_settings
39 #include "dungeongen.h"
43 #include "mg_decoration.h"
44 #include "mapgen_valleys.h"
51 //#include "util/timetaker.h"
52 //#include "profiler.h"
55 //static Profiler mapgen_prof;
56 //Profiler *mapgen_profiler = &mapgen_prof;
58 static FlagDesc flagdesc_mapgen_valleys[] = {
59 {"altitude_chill", MGVALLEYS_ALT_CHILL},
60 {"humid_rivers", MGVALLEYS_HUMID_RIVERS},
64 ///////////////////////////////////////////////////////////////////////////////
67 MapgenValleys::MapgenValleys(int mapgenid, MapgenParams *params, EmergeManager *emerge)
68 : MapgenBasic(mapgenid, params, emerge)
70 // NOTE: MapgenValleys has a hard dependency on BiomeGenOriginal
71 this->m_bgen = (BiomeGenOriginal *)biomegen;
73 this->map_gen_limit = MYMIN(MAX_MAP_GENERATION_LIMIT,
74 g_settings->getU16("map_generation_limit"));
76 MapgenValleysParams *sp = (MapgenValleysParams *)params->sparams;
77 BiomeParamsOriginal *bp = (BiomeParamsOriginal *)params->bparams;
79 this->spflags = sp->spflags;
80 this->altitude_chill = sp->altitude_chill;
81 this->large_cave_depth = sp->large_cave_depth;
82 this->lava_features_lim = rangelim(sp->lava_features, 0, 10);
83 this->massive_cave_depth = sp->massive_cave_depth;
84 this->river_depth_bed = sp->river_depth + 1.f;
85 this->river_size_factor = sp->river_size / 100.f;
86 this->water_features_lim = rangelim(sp->water_features, 0, 10);
87 this->cave_width = sp->cave_width;
90 noise_filler_depth = new Noise(&sp->np_filler_depth, seed, csize.X, csize.Z);
91 noise_inter_valley_slope = new Noise(&sp->np_inter_valley_slope, seed, csize.X, csize.Z);
92 noise_rivers = new Noise(&sp->np_rivers, seed, csize.X, csize.Z);
93 noise_terrain_height = new Noise(&sp->np_terrain_height, seed, csize.X, csize.Z);
94 noise_valley_depth = new Noise(&sp->np_valley_depth, seed, csize.X, csize.Z);
95 noise_valley_profile = new Noise(&sp->np_valley_profile, seed, csize.X, csize.Z);
98 // 1-up 1-down overgeneration
99 noise_inter_valley_fill = new Noise(&sp->np_inter_valley_fill, seed, csize.X, csize.Y + 2, csize.Z);
100 // 1-down overgeneraion
101 noise_cave1 = new Noise(&sp->np_cave1, seed, csize.X, csize.Y + 1, csize.Z);
102 noise_cave2 = new Noise(&sp->np_cave2, seed, csize.X, csize.Y + 1, csize.Z);
103 noise_massive_caves = new Noise(&sp->np_massive_caves, seed, csize.X, csize.Y + 1, csize.Z);
105 this->humid_rivers = (spflags & MGVALLEYS_HUMID_RIVERS);
106 this->use_altitude_chill = (spflags & MGVALLEYS_ALT_CHILL);
107 this->humidity_adjust = bp->np_humidity.offset - 50.f;
109 // a small chance of overflows if the settings are very high
110 this->cave_water_max_height = water_level + MYMAX(0, water_features_lim - 4) * 50;
111 this->lava_max_height = water_level + MYMAX(0, lava_features_lim - 4) * 50;
113 tcave_cache = new float[csize.Y + 2];
115 // Resolve content to be used
116 c_lava_source = ndef->getId("mapgen_lava_source");
120 MapgenValleys::~MapgenValleys()
124 delete noise_filler_depth;
125 delete noise_inter_valley_fill;
126 delete noise_inter_valley_slope;
128 delete noise_massive_caves;
129 delete noise_terrain_height;
130 delete noise_valley_depth;
131 delete noise_valley_profile;
133 delete[] tcave_cache;
137 MapgenValleysParams::MapgenValleysParams()
139 spflags = MGVALLEYS_HUMID_RIVERS | MGVALLEYS_ALT_CHILL;
140 altitude_chill = 90; // The altitude at which temperature drops by 20C.
141 large_cave_depth = -33;
142 lava_features = 0; // How often water will occur in caves.
143 massive_cave_depth = -256; // highest altitude of massive caves
144 river_depth = 4; // How deep to carve river channels.
145 river_size = 5; // How wide to make rivers.
146 water_features = 0; // How often water will occur in caves.
149 np_cave1 = NoiseParams(0, 12, v3f(61, 61, 61), 52534, 3, 0.5, 2.0);
150 np_cave2 = NoiseParams(0, 12, v3f(67, 67, 67), 10325, 3, 0.5, 2.0);
151 np_filler_depth = NoiseParams(0.f, 1.2f, v3f(256, 256, 256), 1605, 3, 0.5f, 2.f);
152 np_inter_valley_fill = NoiseParams(0.f, 1.f, v3f(256, 512, 256), 1993, 6, 0.8f, 2.f);
153 np_inter_valley_slope = NoiseParams(0.5f, 0.5f, v3f(128, 128, 128), 746, 1, 1.f, 2.f);
154 np_rivers = NoiseParams(0.f, 1.f, v3f(256, 256, 256), -6050, 5, 0.6f, 2.f);
155 np_massive_caves = NoiseParams(0.f, 1.f, v3f(768, 256, 768), 59033, 6, 0.63f, 2.f);
156 np_terrain_height = NoiseParams(-10.f, 50.f, v3f(1024, 1024, 1024), 5202, 6, 0.4f, 2.f);
157 np_valley_depth = NoiseParams(5.f, 4.f, v3f(512, 512, 512), -1914, 1, 1.f, 2.f);
158 np_valley_profile = NoiseParams(0.6f, 0.5f, v3f(512, 512, 512), 777, 1, 1.f, 2.f);
162 void MapgenValleysParams::readParams(const Settings *settings)
164 settings->getFlagStrNoEx("mgvalleys_spflags", spflags, flagdesc_mapgen_valleys);
165 settings->getU16NoEx("mgvalleys_altitude_chill", altitude_chill);
166 settings->getS16NoEx("mgvalleys_large_cave_depth", large_cave_depth);
167 settings->getU16NoEx("mgvalleys_lava_features", lava_features);
168 settings->getS16NoEx("mgvalleys_massive_cave_depth", massive_cave_depth);
169 settings->getU16NoEx("mgvalleys_river_depth", river_depth);
170 settings->getU16NoEx("mgvalleys_river_size", river_size);
171 settings->getU16NoEx("mgvalleys_water_features", water_features);
172 settings->getFloatNoEx("mgvalleys_cave_width", cave_width);
174 settings->getNoiseParams("mgvalleys_np_cave1", np_cave1);
175 settings->getNoiseParams("mgvalleys_np_cave2", np_cave2);
176 settings->getNoiseParams("mgvalleys_np_filler_depth", np_filler_depth);
177 settings->getNoiseParams("mgvalleys_np_inter_valley_fill", np_inter_valley_fill);
178 settings->getNoiseParams("mgvalleys_np_inter_valley_slope", np_inter_valley_slope);
179 settings->getNoiseParams("mgvalleys_np_rivers", np_rivers);
180 settings->getNoiseParams("mgvalleys_np_massive_caves", np_massive_caves);
181 settings->getNoiseParams("mgvalleys_np_terrain_height", np_terrain_height);
182 settings->getNoiseParams("mgvalleys_np_valley_depth", np_valley_depth);
183 settings->getNoiseParams("mgvalleys_np_valley_profile", np_valley_profile);
187 void MapgenValleysParams::writeParams(Settings *settings) const
189 settings->setFlagStr("mgvalleys_spflags", spflags, flagdesc_mapgen_valleys, U32_MAX);
190 settings->setU16("mgvalleys_altitude_chill", altitude_chill);
191 settings->setS16("mgvalleys_large_cave_depth", large_cave_depth);
192 settings->setU16("mgvalleys_lava_features", lava_features);
193 settings->setS16("mgvalleys_massive_cave_depth", massive_cave_depth);
194 settings->setU16("mgvalleys_river_depth", river_depth);
195 settings->setU16("mgvalleys_river_size", river_size);
196 settings->setU16("mgvalleys_water_features", water_features);
197 settings->setFloat("mgvalleys_cave_width", cave_width);
199 settings->setNoiseParams("mgvalleys_np_cave1", np_cave1);
200 settings->setNoiseParams("mgvalleys_np_cave2", np_cave2);
201 settings->setNoiseParams("mgvalleys_np_filler_depth", np_filler_depth);
202 settings->setNoiseParams("mgvalleys_np_inter_valley_fill", np_inter_valley_fill);
203 settings->setNoiseParams("mgvalleys_np_inter_valley_slope", np_inter_valley_slope);
204 settings->setNoiseParams("mgvalleys_np_rivers", np_rivers);
205 settings->setNoiseParams("mgvalleys_np_massive_caves", np_massive_caves);
206 settings->setNoiseParams("mgvalleys_np_terrain_height", np_terrain_height);
207 settings->setNoiseParams("mgvalleys_np_valley_depth", np_valley_depth);
208 settings->setNoiseParams("mgvalleys_np_valley_profile", np_valley_profile);
212 ///////////////////////////////////////
215 void MapgenValleys::makeChunk(BlockMakeData *data)
218 assert(data->vmanip);
219 assert(data->nodedef);
220 assert(data->blockpos_requested.X >= data->blockpos_min.X &&
221 data->blockpos_requested.Y >= data->blockpos_min.Y &&
222 data->blockpos_requested.Z >= data->blockpos_min.Z);
223 assert(data->blockpos_requested.X <= data->blockpos_max.X &&
224 data->blockpos_requested.Y <= data->blockpos_max.Y &&
225 data->blockpos_requested.Z <= data->blockpos_max.Z);
227 this->generating = true;
228 this->vm = data->vmanip;
229 this->ndef = data->nodedef;
231 //TimeTaker t("makeChunk");
233 v3s16 blockpos_min = data->blockpos_min;
234 v3s16 blockpos_max = data->blockpos_max;
235 node_min = blockpos_min * MAP_BLOCKSIZE;
236 node_max = (blockpos_max + v3s16(1, 1, 1)) * MAP_BLOCKSIZE - v3s16(1, 1, 1);
237 full_node_min = (blockpos_min - 1) * MAP_BLOCKSIZE;
238 full_node_max = (blockpos_max + 2) * MAP_BLOCKSIZE - v3s16(1, 1, 1);
240 blockseed = getBlockSeed2(full_node_min, seed);
242 // Generate noise maps and base terrain height.
245 // Generate biome noises. Note this must be executed strictly before
246 // generateTerrain, because generateTerrain depends on intermediate
247 // biome-related noises.
248 m_bgen->calcBiomeNoise(node_min);
250 // Generate base terrain with initial heightmaps
251 s16 stone_surface_max_y = generateTerrain();
253 // Place biome-specific nodes and build biomemap
254 MgStoneType stone_type = generateBiomes();
257 if (flags & MG_CAVES)
258 generateCaves(stone_surface_max_y, large_cave_depth);
261 if ((flags & MG_DUNGEONS) && node_max.Y < 50)
262 generateDungeons(stone_surface_max_y, stone_type);
264 // Generate the registered decorations
265 if (flags & MG_DECORATIONS)
266 m_emerge->decomgr->placeAllDecos(this, blockseed, node_min, node_max);
268 // Generate the registered ores
269 m_emerge->oremgr->placeAllOres(this, blockseed, node_min, node_max);
271 // Sprinkle some dust on top after everything else was generated
274 //TimeTaker tll("liquid_lighting");
276 updateLiquid(&data->transforming_liquid, full_node_min, full_node_max);
278 if (flags & MG_LIGHT)
280 node_min - v3s16(0, 1, 0),
281 node_max + v3s16(0, 1, 0),
285 //mapgen_profiler->avg("liquid_lighting", tll.stop() / 1000.f);
286 //mapgen_profiler->avg("makeChunk", t.stop() / 1000.f);
288 this->generating = false;
292 // Populate the noise tables and do most of the
293 // calculation necessary to determine terrain height.
294 void MapgenValleys::calculateNoise()
296 //TimeTaker t("calculateNoise", NULL, PRECISION_MICRO);
299 int y = node_min.Y - 1;
302 //TimeTaker tcn("actualNoise");
304 noise_inter_valley_slope->perlinMap2D(x, z);
305 noise_rivers->perlinMap2D(x, z);
306 noise_terrain_height->perlinMap2D(x, z);
307 noise_valley_depth->perlinMap2D(x, z);
308 noise_valley_profile->perlinMap2D(x, z);
310 noise_inter_valley_fill->perlinMap3D(x, y, z);
312 //mapgen_profiler->avg("noisemaps", tcn.stop() / 1000.f);
314 float heat_offset = 0.f;
315 float humidity_scale = 1.f;
317 // Altitude chill tends to reduce the average heat.
318 if (use_altitude_chill)
321 // River humidity tends to increase the humidity range.
323 humidity_scale = 0.8f;
326 for (s32 index = 0; index < csize.X * csize.Z; index++) {
327 m_bgen->heatmap[index] += heat_offset;
328 m_bgen->humidmap[index] *= humidity_scale;
334 for (tn.z = node_min.Z; tn.z <= node_max.Z; tn.z++)
335 for (tn.x = node_min.X; tn.x <= node_max.X; tn.x++, index++) {
336 // The parameters that we actually need to generate terrain
337 // are passed by address (and the return value).
338 tn.terrain_height = noise_terrain_height->result[index];
339 // River noise is replaced with base terrain, which
340 // is basically the height of the water table.
341 tn.rivers = &noise_rivers->result[index];
342 // Valley depth noise is replaced with the valley
343 // number that represents the height of terrain
344 // over rivers and is used to determine about
345 // how close a river is for humidity calculation.
346 tn.valley = &noise_valley_depth->result[index];
347 tn.valley_profile = noise_valley_profile->result[index];
348 // Slope noise is replaced by the calculated slope
349 // which is used to get terrain height in the slow
350 // method, to create sharper mountains.
351 tn.slope = &noise_inter_valley_slope->result[index];
352 tn.inter_valley_fill = noise_inter_valley_fill->result[index];
354 // This is the actual terrain height.
355 float mount = terrainLevelFromNoise(&tn);
356 noise_terrain_height->result[index] = mount;
361 // This keeps us from having to maintain two similar sets of
362 // complicated code to determine ground level.
363 float MapgenValleys::terrainLevelFromNoise(TerrainNoise *tn)
365 // The square function changes the behaviour of this noise:
366 // very often small, and sometimes very high.
367 float valley_d = MYSQUARE(*tn->valley);
369 // valley_d is here because terrain is generally higher where valleys
370 // are deep (mountains). base represents the height of the
371 // rivers, most of the surface is above.
372 float base = tn->terrain_height + valley_d;
374 // "river" represents the distance from the river, in arbitrary units.
375 float river = fabs(*tn->rivers) - river_size_factor;
377 // Use the curve of the function 1-exp(-(x/a)^2) to model valleys.
378 // Making "a" vary (0 < a <= 1) changes the shape of the valleys.
379 // Try it with a geometry software !
380 // (here x = "river" and a = valley_profile).
381 // "valley" represents the height of the terrain, from the rivers.
383 float t = river / tn->valley_profile;
384 *tn->valley = valley_d * (1.f - exp(- MYSQUARE(t)));
387 // approximate height of the terrain at this point
388 float mount = base + *tn->valley;
390 *tn->slope *= *tn->valley;
392 // Rivers are placed where "river" is negative, so where the original
393 // noise value is close to zero.
394 // Base ground is returned as rivers since it's basically the water table.
397 // Use the the function -sqrt(1-x^2) which models a circle.
400 float t = river / river_size_factor + 1;
401 depth = (river_depth_bed * sqrt(MYMAX(0, 1.f - MYSQUARE(t))));
404 // base - depth : height of the bottom of the river
405 // water_level - 3 : don't make rivers below 3 nodes under the surface
406 // We use three because that's as low as the swamp biomes go.
407 // There is no logical equivalent to this using rangelim.
408 mount = MYMIN(MYMAX(base - depth, (float)(water_level - 3)), mount);
410 // Slope has no influence on rivers.
418 // This avoids duplicating the code in terrainLevelFromNoise, adding
419 // only the final step of terrain generation without a noise map.
420 float MapgenValleys::adjustedTerrainLevelFromNoise(TerrainNoise *tn)
422 float mount = terrainLevelFromNoise(tn);
423 s16 y_start = myround(mount);
425 for (s16 y = y_start; y <= y_start + 1000; y++) {
426 float fill = NoisePerlin3D(&noise_inter_valley_fill->np, tn->x, y, tn->z, seed);
428 if (fill * *tn->slope < y - mount) {
429 mount = MYMAX(y - 1, mount);
438 int MapgenValleys::getSpawnLevelAtPoint(v2s16 p)
440 // Check to make sure this isn't a request for a location in a river.
441 float rivers = NoisePerlin2D(&noise_rivers->np, p.X, p.Y, seed);
442 if (fabs(rivers) < river_size_factor)
443 return MAX_MAP_GENERATION_LIMIT; // Unsuitable spawn point
445 s16 level_at_point = terrainLevelAtPoint(p.X, p.Y);
446 if (level_at_point <= water_level ||
447 level_at_point > water_level + 32)
448 return MAX_MAP_GENERATION_LIMIT; // Unsuitable spawn point
450 return level_at_point;
454 float MapgenValleys::terrainLevelAtPoint(s16 x, s16 z)
458 float rivers = NoisePerlin2D(&noise_rivers->np, x, z, seed);
459 float valley = NoisePerlin2D(&noise_valley_depth->np, x, z, seed);
460 float inter_valley_slope = NoisePerlin2D(&noise_inter_valley_slope->np, x, z, seed);
464 tn.terrain_height = NoisePerlin2D(&noise_terrain_height->np, x, z, seed);
467 tn.valley_profile = NoisePerlin2D(&noise_valley_profile->np, x, z, seed);
468 tn.slope = &inter_valley_slope;
469 tn.inter_valley_fill = 0.f;
471 return adjustedTerrainLevelFromNoise(&tn);
475 int MapgenValleys::generateTerrain()
477 // Raising this reduces the rate of evaporation.
478 static const float evaporation = 300.f;
480 static const float humidity_dropoff = 4.f;
481 // constant to convert altitude chill (compatible with lua) to heat
482 static const float alt_to_heat = 20.f;
483 // humidity reduction by altitude
484 static const float alt_to_humid = 10.f;
486 MapNode n_air(CONTENT_AIR);
487 MapNode n_river_water(c_river_water_source);
488 MapNode n_stone(c_stone);
489 MapNode n_water(c_water_source);
491 v3s16 em = vm->m_area.getExtent();
492 s16 surface_max_y = -MAX_MAP_GENERATION_LIMIT;
495 for (s16 z = node_min.Z; z <= node_max.Z; z++)
496 for (s16 x = node_min.X; x <= node_max.X; x++, index_2d++) {
497 float river_y = noise_rivers->result[index_2d];
498 float surface_y = noise_terrain_height->result[index_2d];
499 float slope = noise_inter_valley_slope->result[index_2d];
500 float t_heat = m_bgen->heatmap[index_2d];
502 heightmap[index_2d] = -MAX_MAP_GENERATION_LIMIT;
504 if (surface_y > surface_max_y)
505 surface_max_y = ceil(surface_y);
508 // Derive heat from (base) altitude. This will be most correct
509 // at rivers, since other surface heights may vary below.
510 if (use_altitude_chill && (surface_y > 0.f || river_y > 0.f))
511 t_heat -= alt_to_heat * MYMAX(surface_y, river_y) / altitude_chill;
513 // If humidity is low or heat is high, lower the water table.
514 float delta = m_bgen->humidmap[index_2d] - 50.f;
516 float t_evap = (t_heat - 32.f) / evaporation;
517 river_y += delta * MYMAX(t_evap, 0.08f);
521 u32 index_3d = (z - node_min.Z) * zstride_1u1d + (x - node_min.X);
522 u32 index_data = vm->m_area.index(x, node_min.Y - 1, z);
524 // Mapgens concern themselves with stone and water.
525 for (s16 y = node_min.Y - 1; y <= node_max.Y + 1; y++) {
526 if (vm->m_data[index_data].getContent() == CONTENT_IGNORE) {
527 float fill = noise_inter_valley_fill->result[index_3d];
528 float surface_delta = (float)y - surface_y;
529 bool river = y + 1 < river_y;
531 if (slope * fill > surface_delta) {
533 vm->m_data[index_data] = n_stone;
534 if (y > heightmap[index_2d])
535 heightmap[index_2d] = y;
536 if (y > surface_max_y)
538 } else if (y <= water_level) {
540 vm->m_data[index_data] = n_water;
543 vm->m_data[index_data] = n_river_water;
545 vm->m_data[index_data] = n_air;
549 vm->m_area.add_y(em, index_data, 1);
553 // This happens if we're generating a chunk that doesn't
554 // contain the terrain surface, in which case, we need
555 // to set heightmap to a value outside of the chunk,
556 // to avoid confusing lua mods that use heightmap.
557 if (heightmap[index_2d] == -MAX_MAP_GENERATION_LIMIT) {
558 s16 surface_y_int = myround(surface_y);
559 if (surface_y_int > node_max.Y + 1 || surface_y_int < node_min.Y - 1) {
560 // If surface_y is outside the chunk, it's good enough.
561 heightmap[index_2d] = surface_y_int;
563 // If the ground is outside of this chunk, but surface_y
564 // is within the chunk, give a value outside.
565 heightmap[index_2d] = node_min.Y - 2;
570 // Use base ground (water table) in a riverbed, to
571 // avoid an unnatural rise in humidity.
572 float t_alt = MYMAX(noise_rivers->result[index_2d], (float)heightmap[index_2d]);
573 float humid = m_bgen->humidmap[index_2d];
574 float water_depth = (t_alt - river_y) / humidity_dropoff;
575 humid *= 1.f + pow(0.5f, MYMAX(water_depth, 1.f));
577 // Reduce humidity with altitude (ignoring riverbeds).
578 // This is similar to the lua version's seawater adjustment,
579 // but doesn't increase the base humidity, which causes
580 // problems with the default biomes.
582 humid -= alt_to_humid * t_alt / altitude_chill;
584 m_bgen->humidmap[index_2d] = humid;
587 // Assign the heat adjusted by any changed altitudes.
588 // The altitude will change about half the time.
589 if (use_altitude_chill) {
590 // ground height ignoring riverbeds
591 float t_alt = MYMAX(noise_rivers->result[index_2d], (float)heightmap[index_2d]);
592 if (humid_rivers && heightmap[index_2d] == (s16)myround(surface_y))
593 // The altitude hasn't changed. Use the first result.
594 m_bgen->heatmap[index_2d] = t_heat;
595 else if (t_alt > 0.f)
596 m_bgen->heatmap[index_2d] -= alt_to_heat * t_alt / altitude_chill;
600 return surface_max_y;
603 void MapgenValleys::generateCaves(s16 max_stone_y, s16 large_cave_depth)
605 if (max_stone_y < node_min.Y)
608 noise_cave1->perlinMap3D(node_min.X, node_min.Y - 1, node_min.Z);
609 noise_cave2->perlinMap3D(node_min.X, node_min.Y - 1, node_min.Z);
611 PseudoRandom ps(blockseed + 72202);
613 MapNode n_air(CONTENT_AIR);
614 MapNode n_lava(c_lava_source);
615 MapNode n_water(c_river_water_source);
617 v3s16 em = vm->m_area.getExtent();
619 // Cave blend distance near YMIN, YMAX
620 const float massive_cave_blend = 128.f;
621 // noise threshold for massive caves
622 const float massive_cave_threshold = 0.6f;
623 // mct: 1 = small rare caves, 0.5 1/3rd ground volume, 0 = 1/2 ground volume.
625 float yblmin = -map_gen_limit + massive_cave_blend * 1.5f;
626 float yblmax = massive_cave_depth - massive_cave_blend * 1.5f;
627 bool made_a_big_one = false;
629 // Cache the tcave values as they only vary by altitude.
630 if (node_max.Y <= massive_cave_depth) {
631 noise_massive_caves->perlinMap3D(node_min.X, node_min.Y - 1, node_min.Z);
633 for (s16 y = node_min.Y - 1; y <= node_max.Y; y++) {
634 float tcave = massive_cave_threshold;
637 float t = (yblmin - y) / massive_cave_blend;
638 tcave += MYSQUARE(t);
639 } else if (y > yblmax) {
640 float t = (y - yblmax) / massive_cave_blend;
641 tcave += MYSQUARE(t);
644 tcave_cache[y - node_min.Y + 1] = tcave;
648 // lava_depth varies between one and ten as you approach
649 // the bottom of the world.
650 s16 lava_depth = ceil((lava_max_height - node_min.Y + 1) * 10.f / map_gen_limit);
651 // This allows random lava spawns to be less common at the surface.
652 s16 lava_chance = MYCUBE(lava_features_lim) * lava_depth;
653 // water_depth varies between ten and one on the way down.
654 s16 water_depth = ceil((map_gen_limit - abs(node_min.Y) + 1) * 10.f / map_gen_limit);
655 // This allows random water spawns to be more common at the surface.
656 s16 water_chance = MYCUBE(water_features_lim) * water_depth;
658 // Reduce the odds of overflows even further.
659 if (node_max.Y > water_level) {
665 for (s16 z = node_min.Z; z <= node_max.Z; z++)
666 for (s16 x = node_min.X; x <= node_max.X; x++, index_2d++) {
667 Biome *biome = (Biome *)m_bmgr->getRaw(biomemap[index_2d]);
668 bool tunnel_air_above = false;
669 bool underground = false;
670 u32 index_data = vm->m_area.index(x, node_max.Y, z);
671 u32 index_3d = (z - node_min.Z) * zstride_1d + csize.Y * ystride + (x - node_min.X);
673 // Dig caves on down loop to check for air above.
674 // Don't excavate the overgenerated stone at node_max.Y + 1,
675 // this creates a 'roof' over the tunnel, preventing light in
676 // tunnels at mapchunk borders when generating mapchunks upwards.
677 // This 'roof' is removed when the mapchunk above is generated.
678 for (s16 y = node_max.Y; y >= node_min.Y - 1; y--,
680 vm->m_area.add_y(em, index_data, -1)) {
682 float terrain = noise_terrain_height->result[index_2d];
685 if (y > terrain + 10)
687 else if (y < terrain - 40)
690 // Dig massive caves.
691 if (node_max.Y <= massive_cave_depth
692 && noise_massive_caves->result[index_3d]
693 > tcave_cache[y - node_min.Y + 1]) {
694 vm->m_data[index_data] = n_air;
695 made_a_big_one = true;
699 content_t c = vm->m_data[index_data].getContent();
700 float d1 = contour(noise_cave1->result[index_3d]);
701 float d2 = contour(noise_cave2->result[index_3d]);
703 // River water is not set as ground content
704 // in the default game. This can produce strange results
705 // when a tunnel undercuts a river. However, that's not for
706 // the mapgen to correct. Fix it in lua.
708 if (d1 * d2 > cave_width && ndef->get(c).is_ground_content) {
710 vm->m_data[index_data] = n_air;
711 tunnel_air_above = true;
712 } else if (c == biome->c_filler || c == biome->c_stone) {
713 if (tunnel_air_above) {
714 // at the tunnel floor
715 s16 sr = ps.range(0, 39);
717 vm->m_area.add_y(em, j, 1);
719 if (sr > terrain - y) {
720 // Put dirt in tunnels near the surface.
722 vm->m_data[index_data] = MapNode(biome->c_filler);
724 vm->m_data[index_data] = MapNode(biome->c_top);
725 } else if (sr < 3 && underground) {
727 if (lava_features_lim > 0 && y <= lava_max_height
728 && c == biome->c_stone && sr < lava_chance)
729 vm->m_data[j] = n_lava;
733 // If sr < 0 then we should have already placed lava --
734 // don't immediately dump water on it.
735 if (water_features_lim > 0 && y <= cave_water_max_height
736 && sr >= 0 && sr < water_chance)
737 vm->m_data[j] = n_water;
741 tunnel_air_above = false;
744 tunnel_air_above = false;
749 if (node_max.Y <= large_cave_depth && !made_a_big_one) {
750 u32 bruises_count = ps.range(0, 2);
751 for (u32 i = 0; i < bruises_count; i++) {
752 CavesRandomWalk cave(ndef, &gennotify, seed, water_level,
753 c_water_source, c_lava_source);
755 cave.makeCave(vm, node_min, node_max, &ps, true, max_stone_y, heightmap);