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, MapgenValleysParams *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 BiomeParamsOriginal *bp = (BiomeParamsOriginal *)params->bparams;
78 this->spflags = params->spflags;
79 this->altitude_chill = params->altitude_chill;
80 this->large_cave_depth = params->large_cave_depth;
81 this->lava_features_lim = rangelim(params->lava_features, 0, 10);
82 this->massive_cave_depth = params->massive_cave_depth;
83 this->river_depth_bed = params->river_depth + 1.f;
84 this->river_size_factor = params->river_size / 100.f;
85 this->water_features_lim = rangelim(params->water_features, 0, 10);
86 this->cave_width = params->cave_width;
89 noise_filler_depth = new Noise(¶ms->np_filler_depth, seed, csize.X, csize.Z);
90 noise_inter_valley_slope = new Noise(¶ms->np_inter_valley_slope, seed, csize.X, csize.Z);
91 noise_rivers = new Noise(¶ms->np_rivers, seed, csize.X, csize.Z);
92 noise_terrain_height = new Noise(¶ms->np_terrain_height, seed, csize.X, csize.Z);
93 noise_valley_depth = new Noise(¶ms->np_valley_depth, seed, csize.X, csize.Z);
94 noise_valley_profile = new Noise(¶ms->np_valley_profile, seed, csize.X, csize.Z);
97 // 1-up 1-down overgeneration
98 noise_inter_valley_fill = new Noise(¶ms->np_inter_valley_fill, seed, csize.X, csize.Y + 2, csize.Z);
99 // 1-down overgeneraion
100 noise_cave1 = new Noise(¶ms->np_cave1, seed, csize.X, csize.Y + 1, csize.Z);
101 noise_cave2 = new Noise(¶ms->np_cave2, seed, csize.X, csize.Y + 1, csize.Z);
102 noise_massive_caves = new Noise(¶ms->np_massive_caves, seed, csize.X, csize.Y + 1, csize.Z);
104 this->humid_rivers = (spflags & MGVALLEYS_HUMID_RIVERS);
105 this->use_altitude_chill = (spflags & MGVALLEYS_ALT_CHILL);
106 this->humidity_adjust = bp->np_humidity.offset - 50.f;
108 // a small chance of overflows if the settings are very high
109 this->cave_water_max_height = water_level + MYMAX(0, water_features_lim - 4) * 50;
110 this->lava_max_height = water_level + MYMAX(0, lava_features_lim - 4) * 50;
112 tcave_cache = new float[csize.Y + 2];
114 // Resolve content to be used
115 c_lava_source = ndef->getId("mapgen_lava_source");
119 MapgenValleys::~MapgenValleys()
123 delete noise_filler_depth;
124 delete noise_inter_valley_fill;
125 delete noise_inter_valley_slope;
127 delete noise_massive_caves;
128 delete noise_terrain_height;
129 delete noise_valley_depth;
130 delete noise_valley_profile;
132 delete[] tcave_cache;
136 MapgenValleysParams::MapgenValleysParams()
138 spflags = MGVALLEYS_HUMID_RIVERS | MGVALLEYS_ALT_CHILL;
139 altitude_chill = 90; // The altitude at which temperature drops by 20C.
140 large_cave_depth = -33;
141 lava_features = 0; // How often water will occur in caves.
142 massive_cave_depth = -256; // highest altitude of massive caves
143 river_depth = 4; // How deep to carve river channels.
144 river_size = 5; // How wide to make rivers.
145 water_features = 0; // How often water will occur in caves.
148 np_cave1 = NoiseParams(0, 12, v3f(61, 61, 61), 52534, 3, 0.5, 2.0);
149 np_cave2 = NoiseParams(0, 12, v3f(67, 67, 67), 10325, 3, 0.5, 2.0);
150 np_filler_depth = NoiseParams(0.f, 1.2f, v3f(256, 256, 256), 1605, 3, 0.5f, 2.f);
151 np_inter_valley_fill = NoiseParams(0.f, 1.f, v3f(256, 512, 256), 1993, 6, 0.8f, 2.f);
152 np_inter_valley_slope = NoiseParams(0.5f, 0.5f, v3f(128, 128, 128), 746, 1, 1.f, 2.f);
153 np_rivers = NoiseParams(0.f, 1.f, v3f(256, 256, 256), -6050, 5, 0.6f, 2.f);
154 np_massive_caves = NoiseParams(0.f, 1.f, v3f(768, 256, 768), 59033, 6, 0.63f, 2.f);
155 np_terrain_height = NoiseParams(-10.f, 50.f, v3f(1024, 1024, 1024), 5202, 6, 0.4f, 2.f);
156 np_valley_depth = NoiseParams(5.f, 4.f, v3f(512, 512, 512), -1914, 1, 1.f, 2.f);
157 np_valley_profile = NoiseParams(0.6f, 0.5f, v3f(512, 512, 512), 777, 1, 1.f, 2.f);
161 void MapgenValleysParams::readParams(const Settings *settings)
163 settings->getFlagStrNoEx("mgvalleys_spflags", spflags, flagdesc_mapgen_valleys);
164 settings->getU16NoEx("mgvalleys_altitude_chill", altitude_chill);
165 settings->getS16NoEx("mgvalleys_large_cave_depth", large_cave_depth);
166 settings->getU16NoEx("mgvalleys_lava_features", lava_features);
167 settings->getS16NoEx("mgvalleys_massive_cave_depth", massive_cave_depth);
168 settings->getU16NoEx("mgvalleys_river_depth", river_depth);
169 settings->getU16NoEx("mgvalleys_river_size", river_size);
170 settings->getU16NoEx("mgvalleys_water_features", water_features);
171 settings->getFloatNoEx("mgvalleys_cave_width", cave_width);
173 settings->getNoiseParams("mgvalleys_np_cave1", np_cave1);
174 settings->getNoiseParams("mgvalleys_np_cave2", np_cave2);
175 settings->getNoiseParams("mgvalleys_np_filler_depth", np_filler_depth);
176 settings->getNoiseParams("mgvalleys_np_inter_valley_fill", np_inter_valley_fill);
177 settings->getNoiseParams("mgvalleys_np_inter_valley_slope", np_inter_valley_slope);
178 settings->getNoiseParams("mgvalleys_np_rivers", np_rivers);
179 settings->getNoiseParams("mgvalleys_np_massive_caves", np_massive_caves);
180 settings->getNoiseParams("mgvalleys_np_terrain_height", np_terrain_height);
181 settings->getNoiseParams("mgvalleys_np_valley_depth", np_valley_depth);
182 settings->getNoiseParams("mgvalleys_np_valley_profile", np_valley_profile);
186 void MapgenValleysParams::writeParams(Settings *settings) const
188 settings->setFlagStr("mgvalleys_spflags", spflags, flagdesc_mapgen_valleys, U32_MAX);
189 settings->setU16("mgvalleys_altitude_chill", altitude_chill);
190 settings->setS16("mgvalleys_large_cave_depth", large_cave_depth);
191 settings->setU16("mgvalleys_lava_features", lava_features);
192 settings->setS16("mgvalleys_massive_cave_depth", massive_cave_depth);
193 settings->setU16("mgvalleys_river_depth", river_depth);
194 settings->setU16("mgvalleys_river_size", river_size);
195 settings->setU16("mgvalleys_water_features", water_features);
196 settings->setFloat("mgvalleys_cave_width", cave_width);
198 settings->setNoiseParams("mgvalleys_np_cave1", np_cave1);
199 settings->setNoiseParams("mgvalleys_np_cave2", np_cave2);
200 settings->setNoiseParams("mgvalleys_np_filler_depth", np_filler_depth);
201 settings->setNoiseParams("mgvalleys_np_inter_valley_fill", np_inter_valley_fill);
202 settings->setNoiseParams("mgvalleys_np_inter_valley_slope", np_inter_valley_slope);
203 settings->setNoiseParams("mgvalleys_np_rivers", np_rivers);
204 settings->setNoiseParams("mgvalleys_np_massive_caves", np_massive_caves);
205 settings->setNoiseParams("mgvalleys_np_terrain_height", np_terrain_height);
206 settings->setNoiseParams("mgvalleys_np_valley_depth", np_valley_depth);
207 settings->setNoiseParams("mgvalleys_np_valley_profile", np_valley_profile);
211 ///////////////////////////////////////
214 void MapgenValleys::makeChunk(BlockMakeData *data)
217 assert(data->vmanip);
218 assert(data->nodedef);
219 assert(data->blockpos_requested.X >= data->blockpos_min.X &&
220 data->blockpos_requested.Y >= data->blockpos_min.Y &&
221 data->blockpos_requested.Z >= data->blockpos_min.Z);
222 assert(data->blockpos_requested.X <= data->blockpos_max.X &&
223 data->blockpos_requested.Y <= data->blockpos_max.Y &&
224 data->blockpos_requested.Z <= data->blockpos_max.Z);
226 this->generating = true;
227 this->vm = data->vmanip;
228 this->ndef = data->nodedef;
230 //TimeTaker t("makeChunk");
232 v3s16 blockpos_min = data->blockpos_min;
233 v3s16 blockpos_max = data->blockpos_max;
234 node_min = blockpos_min * MAP_BLOCKSIZE;
235 node_max = (blockpos_max + v3s16(1, 1, 1)) * MAP_BLOCKSIZE - v3s16(1, 1, 1);
236 full_node_min = (blockpos_min - 1) * MAP_BLOCKSIZE;
237 full_node_max = (blockpos_max + 2) * MAP_BLOCKSIZE - v3s16(1, 1, 1);
239 blockseed = getBlockSeed2(full_node_min, seed);
241 // Generate biome noises. Note this must be executed strictly before
242 // generateTerrain, because generateTerrain depends on intermediate
243 // biome-related noises.
244 m_bgen->calcBiomeNoise(node_min);
246 // Generate noise maps and base terrain height.
247 // Modify heat and humidity maps.
250 // Generate base terrain with initial heightmaps
251 s16 stone_surface_max_y = generateTerrain();
253 // Recalculate heightmap
254 updateHeightmap(node_min, node_max);
256 // Place biome-specific nodes and build biomemap
257 MgStoneType stone_type = generateBiomes();
260 if (flags & MG_CAVES)
261 generateCaves(stone_surface_max_y, large_cave_depth);
264 if ((flags & MG_DUNGEONS) && node_max.Y < 50)
265 generateDungeons(stone_surface_max_y, stone_type);
267 // Generate the registered decorations
268 if (flags & MG_DECORATIONS)
269 m_emerge->decomgr->placeAllDecos(this, blockseed, node_min, node_max);
271 // Generate the registered ores
272 m_emerge->oremgr->placeAllOres(this, blockseed, node_min, node_max);
274 // Sprinkle some dust on top after everything else was generated
277 //TimeTaker tll("liquid_lighting");
279 updateLiquid(&data->transforming_liquid, full_node_min, full_node_max);
281 if (flags & MG_LIGHT)
283 node_min - v3s16(0, 1, 0),
284 node_max + v3s16(0, 1, 0),
288 //mapgen_profiler->avg("liquid_lighting", tll.stop() / 1000.f);
289 //mapgen_profiler->avg("makeChunk", t.stop() / 1000.f);
291 this->generating = false;
295 // Populate the noise tables and do most of the
296 // calculation necessary to determine terrain height.
297 void MapgenValleys::calculateNoise()
299 //TimeTaker t("calculateNoise", NULL, PRECISION_MICRO);
302 int y = node_min.Y - 1;
305 //TimeTaker tcn("actualNoise");
307 noise_inter_valley_slope->perlinMap2D(x, z);
308 noise_rivers->perlinMap2D(x, z);
309 noise_terrain_height->perlinMap2D(x, z);
310 noise_valley_depth->perlinMap2D(x, z);
311 noise_valley_profile->perlinMap2D(x, z);
313 noise_inter_valley_fill->perlinMap3D(x, y, z);
315 //mapgen_profiler->avg("noisemaps", tcn.stop() / 1000.f);
317 float heat_offset = 0.f;
318 float humidity_scale = 1.f;
320 // Altitude chill tends to reduce the average heat.
321 if (use_altitude_chill)
324 // River humidity tends to increase the humidity range.
326 humidity_scale = 0.8f;
329 for (s32 index = 0; index < csize.X * csize.Z; index++) {
330 m_bgen->heatmap[index] += heat_offset;
331 m_bgen->humidmap[index] *= humidity_scale;
337 for (tn.z = node_min.Z; tn.z <= node_max.Z; tn.z++)
338 for (tn.x = node_min.X; tn.x <= node_max.X; tn.x++, index++) {
339 // The parameters that we actually need to generate terrain
340 // are passed by address (and the return value).
341 tn.terrain_height = noise_terrain_height->result[index];
342 // River noise is replaced with base terrain, which
343 // is basically the height of the water table.
344 tn.rivers = &noise_rivers->result[index];
345 // Valley depth noise is replaced with the valley
346 // number that represents the height of terrain
347 // over rivers and is used to determine about
348 // how close a river is for humidity calculation.
349 tn.valley = &noise_valley_depth->result[index];
350 tn.valley_profile = noise_valley_profile->result[index];
351 // Slope noise is replaced by the calculated slope
352 // which is used to get terrain height in the slow
353 // method, to create sharper mountains.
354 tn.slope = &noise_inter_valley_slope->result[index];
355 tn.inter_valley_fill = noise_inter_valley_fill->result[index];
357 // This is the actual terrain height.
358 float mount = terrainLevelFromNoise(&tn);
359 noise_terrain_height->result[index] = mount;
364 // This keeps us from having to maintain two similar sets of
365 // complicated code to determine ground level.
366 float MapgenValleys::terrainLevelFromNoise(TerrainNoise *tn)
368 // The square function changes the behaviour of this noise:
369 // very often small, and sometimes very high.
370 float valley_d = MYSQUARE(*tn->valley);
372 // valley_d is here because terrain is generally higher where valleys
373 // are deep (mountains). base represents the height of the
374 // rivers, most of the surface is above.
375 float base = tn->terrain_height + valley_d;
377 // "river" represents the distance from the river, in arbitrary units.
378 float river = fabs(*tn->rivers) - river_size_factor;
380 // Use the curve of the function 1-exp(-(x/a)^2) to model valleys.
381 // Making "a" vary (0 < a <= 1) changes the shape of the valleys.
382 // Try it with a geometry software !
383 // (here x = "river" and a = valley_profile).
384 // "valley" represents the height of the terrain, from the rivers.
386 float t = river / tn->valley_profile;
387 *tn->valley = valley_d * (1.f - exp(- MYSQUARE(t)));
390 // approximate height of the terrain at this point
391 float mount = base + *tn->valley;
393 *tn->slope *= *tn->valley;
395 // Rivers are placed where "river" is negative, so where the original
396 // noise value is close to zero.
397 // Base ground is returned as rivers since it's basically the water table.
400 // Use the the function -sqrt(1-x^2) which models a circle.
403 float t = river / river_size_factor + 1;
404 depth = (river_depth_bed * sqrt(MYMAX(0, 1.f - MYSQUARE(t))));
407 // base - depth : height of the bottom of the river
408 // water_level - 3 : don't make rivers below 3 nodes under the surface
409 // We use three because that's as low as the swamp biomes go.
410 // There is no logical equivalent to this using rangelim.
411 mount = MYMIN(MYMAX(base - depth, (float)(water_level - 3)), mount);
413 // Slope has no influence on rivers.
421 // This avoids duplicating the code in terrainLevelFromNoise, adding
422 // only the final step of terrain generation without a noise map.
423 float MapgenValleys::adjustedTerrainLevelFromNoise(TerrainNoise *tn)
425 float mount = terrainLevelFromNoise(tn);
426 s16 y_start = myround(mount);
428 for (s16 y = y_start; y <= y_start + 1000; y++) {
429 float fill = NoisePerlin3D(&noise_inter_valley_fill->np, tn->x, y, tn->z, seed);
431 if (fill * *tn->slope < y - mount) {
432 mount = MYMAX(y - 1, mount);
441 int MapgenValleys::getSpawnLevelAtPoint(v2s16 p)
443 // Check to make sure this isn't a request for a location in a river.
444 float rivers = NoisePerlin2D(&noise_rivers->np, p.X, p.Y, seed);
445 if (fabs(rivers) < river_size_factor)
446 return MAX_MAP_GENERATION_LIMIT; // Unsuitable spawn point
448 s16 level_at_point = terrainLevelAtPoint(p.X, p.Y);
449 if (level_at_point <= water_level ||
450 level_at_point > water_level + 32)
451 return MAX_MAP_GENERATION_LIMIT; // Unsuitable spawn point
453 return level_at_point;
457 float MapgenValleys::terrainLevelAtPoint(s16 x, s16 z)
461 float rivers = NoisePerlin2D(&noise_rivers->np, x, z, seed);
462 float valley = NoisePerlin2D(&noise_valley_depth->np, x, z, seed);
463 float inter_valley_slope = NoisePerlin2D(&noise_inter_valley_slope->np, x, z, seed);
467 tn.terrain_height = NoisePerlin2D(&noise_terrain_height->np, x, z, seed);
470 tn.valley_profile = NoisePerlin2D(&noise_valley_profile->np, x, z, seed);
471 tn.slope = &inter_valley_slope;
472 tn.inter_valley_fill = 0.f;
474 return adjustedTerrainLevelFromNoise(&tn);
478 int MapgenValleys::generateTerrain()
480 // Raising this reduces the rate of evaporation.
481 static const float evaporation = 300.f;
483 static const float humidity_dropoff = 4.f;
484 // constant to convert altitude chill (compatible with lua) to heat
485 static const float alt_to_heat = 20.f;
486 // humidity reduction by altitude
487 static const float alt_to_humid = 10.f;
489 MapNode n_air(CONTENT_AIR);
490 MapNode n_river_water(c_river_water_source);
491 MapNode n_stone(c_stone);
492 MapNode n_water(c_water_source);
494 v3s16 em = vm->m_area.getExtent();
495 s16 surface_max_y = -MAX_MAP_GENERATION_LIMIT;
498 for (s16 z = node_min.Z; z <= node_max.Z; z++)
499 for (s16 x = node_min.X; x <= node_max.X; x++, index_2d++) {
500 float river_y = noise_rivers->result[index_2d];
501 float surface_y = noise_terrain_height->result[index_2d];
502 float slope = noise_inter_valley_slope->result[index_2d];
503 float t_heat = m_bgen->heatmap[index_2d];
505 heightmap[index_2d] = -MAX_MAP_GENERATION_LIMIT;
507 if (surface_y > surface_max_y)
508 surface_max_y = ceil(surface_y);
511 // Derive heat from (base) altitude. This will be most correct
512 // at rivers, since other surface heights may vary below.
513 if (use_altitude_chill && (surface_y > 0.f || river_y > 0.f))
514 t_heat -= alt_to_heat * MYMAX(surface_y, river_y) / altitude_chill;
516 // If humidity is low or heat is high, lower the water table.
517 float delta = m_bgen->humidmap[index_2d] - 50.f;
519 float t_evap = (t_heat - 32.f) / evaporation;
520 river_y += delta * MYMAX(t_evap, 0.08f);
524 u32 index_3d = (z - node_min.Z) * zstride_1u1d + (x - node_min.X);
525 u32 index_data = vm->m_area.index(x, node_min.Y - 1, z);
527 // Mapgens concern themselves with stone and water.
528 for (s16 y = node_min.Y - 1; y <= node_max.Y + 1; y++) {
529 if (vm->m_data[index_data].getContent() == CONTENT_IGNORE) {
530 float fill = noise_inter_valley_fill->result[index_3d];
531 float surface_delta = (float)y - surface_y;
532 bool river = y + 1 < river_y;
534 if (slope * fill > surface_delta) {
536 vm->m_data[index_data] = n_stone;
537 if (y > heightmap[index_2d])
538 heightmap[index_2d] = y;
539 if (y > surface_max_y)
541 } else if (y <= water_level) {
543 vm->m_data[index_data] = n_water;
546 vm->m_data[index_data] = n_river_water;
548 vm->m_data[index_data] = n_air;
552 vm->m_area.add_y(em, index_data, 1);
556 if (heightmap[index_2d] == -MAX_MAP_GENERATION_LIMIT) {
557 s16 surface_y_int = myround(surface_y);
558 if (surface_y_int > node_max.Y + 1 || surface_y_int < node_min.Y - 1) {
559 // If surface_y is outside the chunk, it's good enough.
560 heightmap[index_2d] = surface_y_int;
562 // If the ground is outside of this chunk, but surface_y
563 // is within the chunk, give a value outside.
564 heightmap[index_2d] = node_min.Y - 2;
569 // Use base ground (water table) in a riverbed, to
570 // avoid an unnatural rise in humidity.
571 float t_alt = MYMAX(noise_rivers->result[index_2d], (float)heightmap[index_2d]);
572 float humid = m_bgen->humidmap[index_2d];
573 float water_depth = (t_alt - river_y) / humidity_dropoff;
574 humid *= 1.f + pow(0.5f, MYMAX(water_depth, 1.f));
576 // Reduce humidity with altitude (ignoring riverbeds).
577 // This is similar to the lua version's seawater adjustment,
578 // but doesn't increase the base humidity, which causes
579 // problems with the default biomes.
581 humid -= alt_to_humid * t_alt / altitude_chill;
583 m_bgen->humidmap[index_2d] = humid;
586 // Assign the heat adjusted by any changed altitudes.
587 // The altitude will change about half the time.
588 if (use_altitude_chill) {
589 // ground height ignoring riverbeds
590 float t_alt = MYMAX(noise_rivers->result[index_2d], (float)heightmap[index_2d]);
591 if (humid_rivers && heightmap[index_2d] == (s16)myround(surface_y))
592 // The altitude hasn't changed. Use the first result.
593 m_bgen->heatmap[index_2d] = t_heat;
594 else if (t_alt > 0.f)
595 m_bgen->heatmap[index_2d] -= alt_to_heat * t_alt / altitude_chill;
599 return surface_max_y;
602 void MapgenValleys::generateCaves(s16 max_stone_y, s16 large_cave_depth)
604 if (max_stone_y < node_min.Y)
607 noise_cave1->perlinMap3D(node_min.X, node_min.Y - 1, node_min.Z);
608 noise_cave2->perlinMap3D(node_min.X, node_min.Y - 1, node_min.Z);
610 PseudoRandom ps(blockseed + 72202);
612 MapNode n_air(CONTENT_AIR);
613 MapNode n_lava(c_lava_source);
614 MapNode n_water(c_river_water_source);
616 v3s16 em = vm->m_area.getExtent();
618 // Cave blend distance near YMIN, YMAX
619 const float massive_cave_blend = 128.f;
620 // noise threshold for massive caves
621 const float massive_cave_threshold = 0.6f;
622 // mct: 1 = small rare caves, 0.5 1/3rd ground volume, 0 = 1/2 ground volume.
624 float yblmin = -map_gen_limit + massive_cave_blend * 1.5f;
625 float yblmax = massive_cave_depth - massive_cave_blend * 1.5f;
626 bool made_a_big_one = false;
628 // Cache the tcave values as they only vary by altitude.
629 if (node_max.Y <= massive_cave_depth) {
630 noise_massive_caves->perlinMap3D(node_min.X, node_min.Y - 1, node_min.Z);
632 for (s16 y = node_min.Y - 1; y <= node_max.Y; y++) {
633 float tcave = massive_cave_threshold;
636 float t = (yblmin - y) / massive_cave_blend;
637 tcave += MYSQUARE(t);
638 } else if (y > yblmax) {
639 float t = (y - yblmax) / massive_cave_blend;
640 tcave += MYSQUARE(t);
643 tcave_cache[y - node_min.Y + 1] = tcave;
647 // lava_depth varies between one and ten as you approach
648 // the bottom of the world.
649 s16 lava_depth = ceil((lava_max_height - node_min.Y + 1) * 10.f / map_gen_limit);
650 // This allows random lava spawns to be less common at the surface.
651 s16 lava_chance = MYCUBE(lava_features_lim) * lava_depth;
652 // water_depth varies between ten and one on the way down.
653 s16 water_depth = ceil((map_gen_limit - abs(node_min.Y) + 1) * 10.f / map_gen_limit);
654 // This allows random water spawns to be more common at the surface.
655 s16 water_chance = MYCUBE(water_features_lim) * water_depth;
657 // Reduce the odds of overflows even further.
658 if (node_max.Y > water_level) {
664 for (s16 z = node_min.Z; z <= node_max.Z; z++)
665 for (s16 x = node_min.X; x <= node_max.X; x++, index_2d++) {
666 Biome *biome = (Biome *)m_bmgr->getRaw(biomemap[index_2d]);
667 bool tunnel_air_above = false;
668 bool is_under_river = 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 // Detect river water to place riverbed nodes in tunnels
701 if (c == biome->c_river_water)
702 is_under_river = true;
704 float d1 = contour(noise_cave1->result[index_3d]);
705 float d2 = contour(noise_cave2->result[index_3d]);
707 if (d1 * d2 > cave_width && ndef->get(c).is_ground_content) {
709 vm->m_data[index_data] = n_air;
710 tunnel_air_above = true;
711 } else if (c == biome->c_filler || c == biome->c_stone) {
712 if (tunnel_air_above) {
713 // at the tunnel floor
714 s16 sr = ps.range(0, 39);
716 vm->m_area.add_y(em, j, 1);
718 if (sr > terrain - y) {
719 // Put biome nodes in tunnels near the surface
721 vm->m_data[index_data] = MapNode(biome->c_riverbed);
722 else if (underground)
723 vm->m_data[index_data] = MapNode(biome->c_filler);
725 vm->m_data[index_data] = MapNode(biome->c_top);
726 } else if (sr < 3 && underground) {
728 if (lava_features_lim > 0 && y <= lava_max_height
729 && c == biome->c_stone && sr < lava_chance)
730 vm->m_data[j] = n_lava;
734 // If sr < 0 then we should have already placed lava --
735 // don't immediately dump water on it.
736 if (water_features_lim > 0 && y <= cave_water_max_height
737 && sr >= 0 && sr < water_chance)
738 vm->m_data[j] = n_water;
742 tunnel_air_above = false;
745 tunnel_air_above = false;
750 if (node_max.Y <= large_cave_depth && !made_a_big_one) {
751 u32 bruises_count = ps.range(0, 2);
752 for (u32 i = 0; i < bruises_count; i++) {
753 CavesRandomWalk cave(ndef, &gennotify, seed, water_level,
754 c_water_source, c_lava_source);
756 cave.makeCave(vm, node_min, node_max, &ps, true, max_stone_y, heightmap);