3 Copyright (C) 2016-2017 Duane Robertson <duane@duanerobertson.com>
4 Copyright (C) 2016-2017 paramat
6 Based on Valleys Mapgen by Gael de Sailly
7 (https://forum.minetest.net/viewtopic.php?f=9&t=11430)
8 and mapgen_v7, mapgen_flat by kwolekr and paramat.
10 Licensing changed by permission of Gael de Sailly.
12 This program is free software; you can redistribute it and/or modify
13 it under the terms of the GNU Lesser General Public License as published by
14 the Free Software Foundation; either version 2.1 of the License, or
15 (at your option) any later version.
17 This program is distributed in the hope that it will be useful,
18 but WITHOUT ANY WARRANTY; without even the implied warranty of
19 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20 GNU Lesser General Public License for more details.
22 You should have received a copy of the GNU Lesser General Public License along
23 with this program; if not, write to the Free Software Foundation, Inc.,
24 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
34 #include "voxelalgorithms.h"
35 #include "settings.h" // For g_settings
37 #include "dungeongen.h"
40 #include "mg_decoration.h"
41 #include "mapgen_valleys.h"
48 //#include "util/timetaker.h"
49 //#include "profiler.h"
52 //static Profiler mapgen_prof;
53 //Profiler *mapgen_profiler = &mapgen_prof;
55 static FlagDesc flagdesc_mapgen_valleys[] = {
56 {"altitude_chill", MGVALLEYS_ALT_CHILL},
57 {"humid_rivers", MGVALLEYS_HUMID_RIVERS},
61 ///////////////////////////////////////////////////////////////////////////////
64 MapgenValleys::MapgenValleys(int mapgenid, MapgenValleysParams *params, EmergeManager *emerge)
65 : MapgenBasic(mapgenid, params, emerge)
67 // NOTE: MapgenValleys has a hard dependency on BiomeGenOriginal
68 m_bgen = (BiomeGenOriginal *)biomegen;
70 BiomeParamsOriginal *bp = (BiomeParamsOriginal *)params->bparams;
72 spflags = params->spflags;
73 altitude_chill = params->altitude_chill;
74 large_cave_depth = params->large_cave_depth;
75 lava_features_lim = rangelim(params->lava_features, 0, 10);
76 massive_cave_depth = params->massive_cave_depth;
77 river_depth_bed = params->river_depth + 1.f;
78 river_size_factor = params->river_size / 100.f;
79 water_features_lim = rangelim(params->water_features, 0, 10);
80 cave_width = params->cave_width;
83 noise_filler_depth = new Noise(¶ms->np_filler_depth, seed, csize.X, csize.Z);
84 noise_inter_valley_slope = new Noise(¶ms->np_inter_valley_slope, seed, csize.X, csize.Z);
85 noise_rivers = new Noise(¶ms->np_rivers, seed, csize.X, csize.Z);
86 noise_terrain_height = new Noise(¶ms->np_terrain_height, seed, csize.X, csize.Z);
87 noise_valley_depth = new Noise(¶ms->np_valley_depth, seed, csize.X, csize.Z);
88 noise_valley_profile = new Noise(¶ms->np_valley_profile, seed, csize.X, csize.Z);
91 // 1-up 1-down overgeneration
92 noise_inter_valley_fill = new Noise(¶ms->np_inter_valley_fill, seed, csize.X, csize.Y + 2, csize.Z);
93 // 1-down overgeneraion
94 noise_cave1 = new Noise(¶ms->np_cave1, seed, csize.X, csize.Y + 1, csize.Z);
95 noise_cave2 = new Noise(¶ms->np_cave2, seed, csize.X, csize.Y + 1, csize.Z);
96 noise_massive_caves = new Noise(¶ms->np_massive_caves, seed, csize.X, csize.Y + 1, csize.Z);
98 humid_rivers = (spflags & MGVALLEYS_HUMID_RIVERS);
99 use_altitude_chill = (spflags & MGVALLEYS_ALT_CHILL);
100 humidity_adjust = bp->np_humidity.offset - 50.f;
102 // a small chance of overflows if the settings are very high
103 cave_water_max_height = water_level + MYMAX(0, water_features_lim - 4) * 50;
104 lava_max_height = water_level + MYMAX(0, lava_features_lim - 4) * 50;
106 tcave_cache = new float[csize.Y + 2];
110 MapgenValleys::~MapgenValleys()
114 delete noise_filler_depth;
115 delete noise_inter_valley_fill;
116 delete noise_inter_valley_slope;
118 delete noise_massive_caves;
119 delete noise_terrain_height;
120 delete noise_valley_depth;
121 delete noise_valley_profile;
123 delete[] tcave_cache;
127 MapgenValleysParams::MapgenValleysParams():
128 np_cave1 (0, 12, v3f(61, 61, 61), 52534, 3, 0.5, 2.0),
129 np_cave2 (0, 12, v3f(67, 67, 67), 10325, 3, 0.5, 2.0),
130 np_filler_depth (0.f, 1.2f, v3f(256, 256, 256), 1605, 3, 0.5f, 2.f),
131 np_inter_valley_fill (0.f, 1.f, v3f(256, 512, 256), 1993, 6, 0.8f, 2.f),
132 np_inter_valley_slope (0.5f, 0.5f, v3f(128, 128, 128), 746, 1, 1.f, 2.f),
133 np_rivers (0.f, 1.f, v3f(256, 256, 256), -6050, 5, 0.6f, 2.f),
134 np_massive_caves (0.f, 1.f, v3f(768, 256, 768), 59033, 6, 0.63f, 2.f),
135 np_terrain_height (-10.f, 50.f, v3f(1024, 1024, 1024), 5202, 6, 0.4f, 2.f),
136 np_valley_depth (5.f, 4.f, v3f(512, 512, 512), -1914, 1, 1.f, 2.f),
137 np_valley_profile (0.6f, 0.5f, v3f(512, 512, 512), 777, 1, 1.f, 2.f)
142 void MapgenValleysParams::readParams(const Settings *settings)
144 settings->getFlagStrNoEx("mgvalleys_spflags", spflags, flagdesc_mapgen_valleys);
145 settings->getU16NoEx("mgvalleys_altitude_chill", altitude_chill);
146 settings->getS16NoEx("mgvalleys_large_cave_depth", large_cave_depth);
147 settings->getU16NoEx("mgvalleys_lava_features", lava_features);
148 settings->getS16NoEx("mgvalleys_massive_cave_depth", massive_cave_depth);
149 settings->getU16NoEx("mgvalleys_river_depth", river_depth);
150 settings->getU16NoEx("mgvalleys_river_size", river_size);
151 settings->getU16NoEx("mgvalleys_water_features", water_features);
152 settings->getFloatNoEx("mgvalleys_cave_width", cave_width);
154 settings->getNoiseParams("mgvalleys_np_cave1", np_cave1);
155 settings->getNoiseParams("mgvalleys_np_cave2", np_cave2);
156 settings->getNoiseParams("mgvalleys_np_filler_depth", np_filler_depth);
157 settings->getNoiseParams("mgvalleys_np_inter_valley_fill", np_inter_valley_fill);
158 settings->getNoiseParams("mgvalleys_np_inter_valley_slope", np_inter_valley_slope);
159 settings->getNoiseParams("mgvalleys_np_rivers", np_rivers);
160 settings->getNoiseParams("mgvalleys_np_massive_caves", np_massive_caves);
161 settings->getNoiseParams("mgvalleys_np_terrain_height", np_terrain_height);
162 settings->getNoiseParams("mgvalleys_np_valley_depth", np_valley_depth);
163 settings->getNoiseParams("mgvalleys_np_valley_profile", np_valley_profile);
167 void MapgenValleysParams::writeParams(Settings *settings) const
169 settings->setFlagStr("mgvalleys_spflags", spflags, flagdesc_mapgen_valleys, U32_MAX);
170 settings->setU16("mgvalleys_altitude_chill", altitude_chill);
171 settings->setS16("mgvalleys_large_cave_depth", large_cave_depth);
172 settings->setU16("mgvalleys_lava_features", lava_features);
173 settings->setS16("mgvalleys_massive_cave_depth", massive_cave_depth);
174 settings->setU16("mgvalleys_river_depth", river_depth);
175 settings->setU16("mgvalleys_river_size", river_size);
176 settings->setU16("mgvalleys_water_features", water_features);
177 settings->setFloat("mgvalleys_cave_width", cave_width);
179 settings->setNoiseParams("mgvalleys_np_cave1", np_cave1);
180 settings->setNoiseParams("mgvalleys_np_cave2", np_cave2);
181 settings->setNoiseParams("mgvalleys_np_filler_depth", np_filler_depth);
182 settings->setNoiseParams("mgvalleys_np_inter_valley_fill", np_inter_valley_fill);
183 settings->setNoiseParams("mgvalleys_np_inter_valley_slope", np_inter_valley_slope);
184 settings->setNoiseParams("mgvalleys_np_rivers", np_rivers);
185 settings->setNoiseParams("mgvalleys_np_massive_caves", np_massive_caves);
186 settings->setNoiseParams("mgvalleys_np_terrain_height", np_terrain_height);
187 settings->setNoiseParams("mgvalleys_np_valley_depth", np_valley_depth);
188 settings->setNoiseParams("mgvalleys_np_valley_profile", np_valley_profile);
192 ///////////////////////////////////////
195 void MapgenValleys::makeChunk(BlockMakeData *data)
198 assert(data->vmanip);
199 assert(data->nodedef);
200 assert(data->blockpos_requested.X >= data->blockpos_min.X &&
201 data->blockpos_requested.Y >= data->blockpos_min.Y &&
202 data->blockpos_requested.Z >= data->blockpos_min.Z);
203 assert(data->blockpos_requested.X <= data->blockpos_max.X &&
204 data->blockpos_requested.Y <= data->blockpos_max.Y &&
205 data->blockpos_requested.Z <= data->blockpos_max.Z);
207 this->generating = true;
208 this->vm = data->vmanip;
209 this->ndef = data->nodedef;
211 //TimeTaker t("makeChunk");
213 v3s16 blockpos_min = data->blockpos_min;
214 v3s16 blockpos_max = data->blockpos_max;
215 node_min = blockpos_min * MAP_BLOCKSIZE;
216 node_max = (blockpos_max + v3s16(1, 1, 1)) * MAP_BLOCKSIZE - v3s16(1, 1, 1);
217 full_node_min = (blockpos_min - 1) * MAP_BLOCKSIZE;
218 full_node_max = (blockpos_max + 2) * MAP_BLOCKSIZE - v3s16(1, 1, 1);
220 blockseed = getBlockSeed2(full_node_min, seed);
222 // Generate biome noises. Note this must be executed strictly before
223 // generateTerrain, because generateTerrain depends on intermediate
224 // biome-related noises.
225 m_bgen->calcBiomeNoise(node_min);
227 // Generate noise maps and base terrain height.
228 // Modify heat and humidity maps.
231 // Generate base terrain with initial heightmaps
232 s16 stone_surface_max_y = generateTerrain();
234 // Recalculate heightmap
235 updateHeightmap(node_min, node_max);
237 // Place biome-specific nodes and build biomemap
238 MgStoneType mgstone_type;
239 content_t biome_stone;
240 generateBiomes(&mgstone_type, &biome_stone);
243 if (flags & MG_CAVES)
244 generateCaves(stone_surface_max_y, large_cave_depth);
247 if ((flags & MG_DUNGEONS) && node_max.Y < 50)
248 generateDungeons(stone_surface_max_y, mgstone_type, biome_stone);
250 // Generate the registered decorations
251 if (flags & MG_DECORATIONS)
252 m_emerge->decomgr->placeAllDecos(this, blockseed, node_min, node_max);
254 // Generate the registered ores
255 m_emerge->oremgr->placeAllOres(this, blockseed, node_min, node_max);
257 // Sprinkle some dust on top after everything else was generated
260 //TimeTaker tll("liquid_lighting");
262 updateLiquid(&data->transforming_liquid, full_node_min, full_node_max);
264 if (flags & MG_LIGHT)
266 node_min - v3s16(0, 1, 0),
267 node_max + v3s16(0, 1, 0),
271 //mapgen_profiler->avg("liquid_lighting", tll.stop() / 1000.f);
272 //mapgen_profiler->avg("makeChunk", t.stop() / 1000.f);
274 this->generating = false;
278 // Populate the noise tables and do most of the
279 // calculation necessary to determine terrain height.
280 void MapgenValleys::calculateNoise()
282 //TimeTaker t("calculateNoise", NULL, PRECISION_MICRO);
285 int y = node_min.Y - 1;
288 //TimeTaker tcn("actualNoise");
290 noise_inter_valley_slope->perlinMap2D(x, z);
291 noise_rivers->perlinMap2D(x, z);
292 noise_terrain_height->perlinMap2D(x, z);
293 noise_valley_depth->perlinMap2D(x, z);
294 noise_valley_profile->perlinMap2D(x, z);
296 noise_inter_valley_fill->perlinMap3D(x, y, z);
298 //mapgen_profiler->avg("noisemaps", tcn.stop() / 1000.f);
300 float heat_offset = 0.f;
301 float humidity_scale = 1.f;
303 // Altitude chill tends to reduce the average heat.
304 if (use_altitude_chill)
307 // River humidity tends to increase the humidity range.
309 humidity_scale = 0.8f;
312 for (s32 index = 0; index < csize.X * csize.Z; index++) {
313 m_bgen->heatmap[index] += heat_offset;
314 m_bgen->humidmap[index] *= humidity_scale;
320 for (tn.z = node_min.Z; tn.z <= node_max.Z; tn.z++)
321 for (tn.x = node_min.X; tn.x <= node_max.X; tn.x++, index++) {
322 // The parameters that we actually need to generate terrain
323 // are passed by address (and the return value).
324 tn.terrain_height = noise_terrain_height->result[index];
325 // River noise is replaced with base terrain, which
326 // is basically the height of the water table.
327 tn.rivers = &noise_rivers->result[index];
328 // Valley depth noise is replaced with the valley
329 // number that represents the height of terrain
330 // over rivers and is used to determine about
331 // how close a river is for humidity calculation.
332 tn.valley = &noise_valley_depth->result[index];
333 tn.valley_profile = noise_valley_profile->result[index];
334 // Slope noise is replaced by the calculated slope
335 // which is used to get terrain height in the slow
336 // method, to create sharper mountains.
337 tn.slope = &noise_inter_valley_slope->result[index];
338 tn.inter_valley_fill = noise_inter_valley_fill->result[index];
340 // This is the actual terrain height.
341 float mount = terrainLevelFromNoise(&tn);
342 noise_terrain_height->result[index] = mount;
347 // This keeps us from having to maintain two similar sets of
348 // complicated code to determine ground level.
349 float MapgenValleys::terrainLevelFromNoise(TerrainNoise *tn)
351 // The square function changes the behaviour of this noise:
352 // very often small, and sometimes very high.
353 float valley_d = MYSQUARE(*tn->valley);
355 // valley_d is here because terrain is generally higher where valleys
356 // are deep (mountains). base represents the height of the
357 // rivers, most of the surface is above.
358 float base = tn->terrain_height + valley_d;
360 // "river" represents the distance from the river, in arbitrary units.
361 float river = fabs(*tn->rivers) - river_size_factor;
363 // Use the curve of the function 1-exp(-(x/a)^2) to model valleys.
364 // Making "a" vary (0 < a <= 1) changes the shape of the valleys.
365 // Try it with a geometry software !
366 // (here x = "river" and a = valley_profile).
367 // "valley" represents the height of the terrain, from the rivers.
369 float t = river / tn->valley_profile;
370 *tn->valley = valley_d * (1.f - exp(- MYSQUARE(t)));
373 // approximate height of the terrain at this point
374 float mount = base + *tn->valley;
376 *tn->slope *= *tn->valley;
378 // Rivers are placed where "river" is negative, so where the original
379 // noise value is close to zero.
380 // Base ground is returned as rivers since it's basically the water table.
383 // Use the the function -sqrt(1-x^2) which models a circle.
386 float t = river / river_size_factor + 1;
387 depth = (river_depth_bed * sqrt(MYMAX(0, 1.f - MYSQUARE(t))));
390 // base - depth : height of the bottom of the river
391 // water_level - 3 : don't make rivers below 3 nodes under the surface
392 // We use three because that's as low as the swamp biomes go.
393 // There is no logical equivalent to this using rangelim.
394 mount = MYMIN(MYMAX(base - depth, (float)(water_level - 3)), mount);
396 // Slope has no influence on rivers.
404 // This avoids duplicating the code in terrainLevelFromNoise, adding
405 // only the final step of terrain generation without a noise map.
406 float MapgenValleys::adjustedTerrainLevelFromNoise(TerrainNoise *tn)
408 float mount = terrainLevelFromNoise(tn);
409 s16 y_start = myround(mount);
411 for (s16 y = y_start; y <= y_start + 1000; y++) {
412 float fill = NoisePerlin3D(&noise_inter_valley_fill->np, tn->x, y, tn->z, seed);
414 if (fill * *tn->slope < y - mount) {
415 mount = MYMAX(y - 1, mount);
424 int MapgenValleys::getSpawnLevelAtPoint(v2s16 p)
426 // Check to make sure this isn't a request for a location in a river.
427 float rivers = NoisePerlin2D(&noise_rivers->np, p.X, p.Y, seed);
428 if (fabs(rivers) < river_size_factor)
429 return MAX_MAP_GENERATION_LIMIT; // Unsuitable spawn point
431 s16 level_at_point = terrainLevelAtPoint(p.X, p.Y);
432 if (level_at_point <= water_level ||
433 level_at_point > water_level + 32)
434 return MAX_MAP_GENERATION_LIMIT; // Unsuitable spawn point
436 return level_at_point;
440 float MapgenValleys::terrainLevelAtPoint(s16 x, s16 z)
444 float rivers = NoisePerlin2D(&noise_rivers->np, x, z, seed);
445 float valley = NoisePerlin2D(&noise_valley_depth->np, x, z, seed);
446 float inter_valley_slope = NoisePerlin2D(&noise_inter_valley_slope->np, x, z, seed);
450 tn.terrain_height = NoisePerlin2D(&noise_terrain_height->np, x, z, seed);
453 tn.valley_profile = NoisePerlin2D(&noise_valley_profile->np, x, z, seed);
454 tn.slope = &inter_valley_slope;
455 tn.inter_valley_fill = 0.f;
457 return adjustedTerrainLevelFromNoise(&tn);
461 int MapgenValleys::generateTerrain()
463 // Raising this reduces the rate of evaporation.
464 static const float evaporation = 300.f;
466 static const float humidity_dropoff = 4.f;
467 // constant to convert altitude chill (compatible with lua) to heat
468 static const float alt_to_heat = 20.f;
469 // humidity reduction by altitude
470 static const float alt_to_humid = 10.f;
472 MapNode n_air(CONTENT_AIR);
473 MapNode n_river_water(c_river_water_source);
474 MapNode n_stone(c_stone);
475 MapNode n_water(c_water_source);
477 const v3s16 &em = vm->m_area.getExtent();
478 s16 surface_max_y = -MAX_MAP_GENERATION_LIMIT;
481 for (s16 z = node_min.Z; z <= node_max.Z; z++)
482 for (s16 x = node_min.X; x <= node_max.X; x++, index_2d++) {
483 float river_y = noise_rivers->result[index_2d];
484 float surface_y = noise_terrain_height->result[index_2d];
485 float slope = noise_inter_valley_slope->result[index_2d];
486 float t_heat = m_bgen->heatmap[index_2d];
488 heightmap[index_2d] = -MAX_MAP_GENERATION_LIMIT;
490 if (surface_y > surface_max_y)
491 surface_max_y = ceil(surface_y);
494 // Derive heat from (base) altitude. This will be most correct
495 // at rivers, since other surface heights may vary below.
496 if (use_altitude_chill && (surface_y > 0.f || river_y > 0.f))
497 t_heat -= alt_to_heat * MYMAX(surface_y, river_y) / altitude_chill;
499 // If humidity is low or heat is high, lower the water table.
500 float delta = m_bgen->humidmap[index_2d] - 50.f;
502 float t_evap = (t_heat - 32.f) / evaporation;
503 river_y += delta * MYMAX(t_evap, 0.08f);
507 u32 index_3d = (z - node_min.Z) * zstride_1u1d + (x - node_min.X);
508 u32 index_data = vm->m_area.index(x, node_min.Y - 1, z);
510 // Mapgens concern themselves with stone and water.
511 for (s16 y = node_min.Y - 1; y <= node_max.Y + 1; y++) {
512 if (vm->m_data[index_data].getContent() == CONTENT_IGNORE) {
513 float fill = noise_inter_valley_fill->result[index_3d];
514 float surface_delta = (float)y - surface_y;
515 bool river = y + 1 < river_y;
517 if (slope * fill > surface_delta) {
519 vm->m_data[index_data] = n_stone;
520 if (y > heightmap[index_2d])
521 heightmap[index_2d] = y;
522 if (y > surface_max_y)
524 } else if (y <= water_level) {
526 vm->m_data[index_data] = n_water;
529 vm->m_data[index_data] = n_river_water;
531 vm->m_data[index_data] = n_air;
535 vm->m_area.add_y(em, index_data, 1);
539 if (heightmap[index_2d] == -MAX_MAP_GENERATION_LIMIT) {
540 s16 surface_y_int = myround(surface_y);
541 if (surface_y_int > node_max.Y + 1 || surface_y_int < node_min.Y - 1) {
542 // If surface_y is outside the chunk, it's good enough.
543 heightmap[index_2d] = surface_y_int;
545 // If the ground is outside of this chunk, but surface_y
546 // is within the chunk, give a value outside.
547 heightmap[index_2d] = node_min.Y - 2;
552 // Use base ground (water table) in a riverbed, to
553 // avoid an unnatural rise in humidity.
554 float t_alt = MYMAX(noise_rivers->result[index_2d], (float)heightmap[index_2d]);
555 float humid = m_bgen->humidmap[index_2d];
556 float water_depth = (t_alt - river_y) / humidity_dropoff;
557 humid *= 1.f + pow(0.5f, MYMAX(water_depth, 1.f));
559 // Reduce humidity with altitude (ignoring riverbeds).
560 // This is similar to the lua version's seawater adjustment,
561 // but doesn't increase the base humidity, which causes
562 // problems with the default biomes.
564 humid -= alt_to_humid * t_alt / altitude_chill;
566 m_bgen->humidmap[index_2d] = humid;
569 // Assign the heat adjusted by any changed altitudes.
570 // The altitude will change about half the time.
571 if (use_altitude_chill) {
572 // ground height ignoring riverbeds
573 float t_alt = MYMAX(noise_rivers->result[index_2d], (float)heightmap[index_2d]);
574 if (humid_rivers && heightmap[index_2d] == (s16)myround(surface_y))
575 // The altitude hasn't changed. Use the first result.
576 m_bgen->heatmap[index_2d] = t_heat;
577 else if (t_alt > 0.f)
578 m_bgen->heatmap[index_2d] -= alt_to_heat * t_alt / altitude_chill;
582 return surface_max_y;
585 void MapgenValleys::generateCaves(s16 max_stone_y, s16 large_cave_depth)
587 if (max_stone_y < node_min.Y)
590 noise_cave1->perlinMap3D(node_min.X, node_min.Y - 1, node_min.Z);
591 noise_cave2->perlinMap3D(node_min.X, node_min.Y - 1, node_min.Z);
593 PseudoRandom ps(blockseed + 72202);
595 MapNode n_air(CONTENT_AIR);
596 MapNode n_lava(c_lava_source);
597 MapNode n_water(c_river_water_source);
599 const v3s16 &em = vm->m_area.getExtent();
601 // Cave blend distance near YMIN, YMAX
602 const float massive_cave_blend = 128.f;
603 // noise threshold for massive caves
604 const float massive_cave_threshold = 0.6f;
605 // mct: 1 = small rare caves, 0.5 1/3rd ground volume, 0 = 1/2 ground volume.
607 float yblmin = -mapgen_limit + massive_cave_blend * 1.5f;
608 float yblmax = massive_cave_depth - massive_cave_blend * 1.5f;
609 bool made_a_big_one = false;
611 // Cache the tcave values as they only vary by altitude.
612 if (node_max.Y <= massive_cave_depth) {
613 noise_massive_caves->perlinMap3D(node_min.X, node_min.Y - 1, node_min.Z);
615 for (s16 y = node_min.Y - 1; y <= node_max.Y; y++) {
616 float tcave = massive_cave_threshold;
619 float t = (yblmin - y) / massive_cave_blend;
620 tcave += MYSQUARE(t);
621 } else if (y > yblmax) {
622 float t = (y - yblmax) / massive_cave_blend;
623 tcave += MYSQUARE(t);
626 tcave_cache[y - node_min.Y + 1] = tcave;
630 // lava_depth varies between one and ten as you approach
631 // the bottom of the world.
632 s16 lava_depth = ceil((lava_max_height - node_min.Y + 1) * 10.f / mapgen_limit);
633 // This allows random lava spawns to be less common at the surface.
634 s16 lava_chance = MYCUBE(lava_features_lim) * lava_depth;
635 // water_depth varies between ten and one on the way down.
636 s16 water_depth = ceil((mapgen_limit - abs(node_min.Y) + 1) * 10.f / mapgen_limit);
637 // This allows random water spawns to be more common at the surface.
638 s16 water_chance = MYCUBE(water_features_lim) * water_depth;
640 // Reduce the odds of overflows even further.
641 if (node_max.Y > water_level) {
647 for (s16 z = node_min.Z; z <= node_max.Z; z++)
648 for (s16 x = node_min.X; x <= node_max.X; x++, index_2d++) {
649 Biome *biome = (Biome *)m_bmgr->getRaw(biomemap[index_2d]);
650 bool tunnel_air_above = false;
651 bool is_under_river = false;
652 bool underground = false;
653 u32 index_data = vm->m_area.index(x, node_max.Y, z);
654 u32 index_3d = (z - node_min.Z) * zstride_1d + csize.Y * ystride + (x - node_min.X);
656 // Dig caves on down loop to check for air above.
657 // Don't excavate the overgenerated stone at node_max.Y + 1,
658 // this creates a 'roof' over the tunnel, preventing light in
659 // tunnels at mapchunk borders when generating mapchunks upwards.
660 // This 'roof' is removed when the mapchunk above is generated.
661 for (s16 y = node_max.Y; y >= node_min.Y - 1; y--,
663 vm->m_area.add_y(em, index_data, -1)) {
665 float terrain = noise_terrain_height->result[index_2d];
668 if (y > terrain + 10)
671 if (y < terrain - 40)
674 // Dig massive caves.
675 if (node_max.Y <= massive_cave_depth
676 && noise_massive_caves->result[index_3d]
677 > tcave_cache[y - node_min.Y + 1]) {
678 vm->m_data[index_data] = n_air;
679 made_a_big_one = true;
683 content_t c = vm->m_data[index_data].getContent();
684 // Detect river water to place riverbed nodes in tunnels
685 if (c == biome->c_river_water)
686 is_under_river = true;
688 float d1 = contour(noise_cave1->result[index_3d]);
689 float d2 = contour(noise_cave2->result[index_3d]);
691 if (d1 * d2 > cave_width && ndef->get(c).is_ground_content) {
693 vm->m_data[index_data] = n_air;
694 tunnel_air_above = true;
695 } else if (c == biome->c_filler || c == biome->c_stone) {
696 if (tunnel_air_above) {
697 // at the tunnel floor
698 s16 sr = ps.range(0, 39);
700 vm->m_area.add_y(em, j, 1);
702 if (sr > terrain - y) {
703 // Put biome nodes in tunnels near the surface
705 vm->m_data[index_data] = MapNode(biome->c_riverbed);
706 else if (underground)
707 vm->m_data[index_data] = MapNode(biome->c_filler);
709 vm->m_data[index_data] = MapNode(biome->c_top);
710 } else if (sr < 3 && underground) {
712 if (lava_features_lim > 0 && y <= lava_max_height
713 && c == biome->c_stone && sr < lava_chance)
714 vm->m_data[j] = n_lava;
718 // If sr < 0 then we should have already placed lava --
719 // don't immediately dump water on it.
720 if (water_features_lim > 0 && y <= cave_water_max_height
721 && sr >= 0 && sr < water_chance)
722 vm->m_data[j] = n_water;
726 tunnel_air_above = false;
729 tunnel_air_above = false;
734 if (node_max.Y <= large_cave_depth && !made_a_big_one) {
735 u32 bruises_count = ps.range(0, 2);
736 for (u32 i = 0; i < bruises_count; i++) {
737 CavesRandomWalk cave(ndef, &gennotify, seed, water_level,
738 c_water_source, c_lava_source, lava_max_height);
740 cave.makeCave(vm, node_min, node_max, &ps, true, max_stone_y, heightmap);