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.
33 #include "content_sao.h"
35 #include "voxelalgorithms.h"
36 #include "settings.h" // For g_settings
38 #include "dungeongen.h"
41 #include "mg_decoration.h"
42 #include "mapgen_valleys.h"
49 //#include "util/timetaker.h"
50 //#include "profiler.h"
53 //static Profiler mapgen_prof;
54 //Profiler *mapgen_profiler = &mapgen_prof;
56 static FlagDesc flagdesc_mapgen_valleys[] = {
57 {"altitude_chill", MGVALLEYS_ALT_CHILL},
58 {"humid_rivers", MGVALLEYS_HUMID_RIVERS},
62 ///////////////////////////////////////////////////////////////////////////////
65 MapgenValleys::MapgenValleys(int mapgenid, MapgenValleysParams *params, EmergeManager *emerge)
66 : MapgenBasic(mapgenid, params, emerge)
68 // NOTE: MapgenValleys has a hard dependency on BiomeGenOriginal
69 m_bgen = (BiomeGenOriginal *)biomegen;
71 BiomeParamsOriginal *bp = (BiomeParamsOriginal *)params->bparams;
73 spflags = params->spflags;
74 altitude_chill = params->altitude_chill;
75 large_cave_depth = params->large_cave_depth;
76 lava_features_lim = rangelim(params->lava_features, 0, 10);
77 massive_cave_depth = params->massive_cave_depth;
78 river_depth_bed = params->river_depth + 1.f;
79 river_size_factor = params->river_size / 100.f;
80 water_features_lim = rangelim(params->water_features, 0, 10);
81 cave_width = params->cave_width;
84 noise_filler_depth = new Noise(¶ms->np_filler_depth, seed, csize.X, csize.Z);
85 noise_inter_valley_slope = new Noise(¶ms->np_inter_valley_slope, seed, csize.X, csize.Z);
86 noise_rivers = new Noise(¶ms->np_rivers, seed, csize.X, csize.Z);
87 noise_terrain_height = new Noise(¶ms->np_terrain_height, seed, csize.X, csize.Z);
88 noise_valley_depth = new Noise(¶ms->np_valley_depth, seed, csize.X, csize.Z);
89 noise_valley_profile = new Noise(¶ms->np_valley_profile, seed, csize.X, csize.Z);
92 // 1-up 1-down overgeneration
93 noise_inter_valley_fill = new Noise(¶ms->np_inter_valley_fill, seed, csize.X, csize.Y + 2, csize.Z);
94 // 1-down overgeneraion
95 noise_cave1 = new Noise(¶ms->np_cave1, seed, csize.X, csize.Y + 1, csize.Z);
96 noise_cave2 = new Noise(¶ms->np_cave2, seed, csize.X, csize.Y + 1, csize.Z);
97 noise_massive_caves = new Noise(¶ms->np_massive_caves, seed, csize.X, csize.Y + 1, csize.Z);
99 humid_rivers = (spflags & MGVALLEYS_HUMID_RIVERS);
100 use_altitude_chill = (spflags & MGVALLEYS_ALT_CHILL);
101 humidity_adjust = bp->np_humidity.offset - 50.f;
103 // a small chance of overflows if the settings are very high
104 cave_water_max_height = water_level + MYMAX(0, water_features_lim - 4) * 50;
105 lava_max_height = water_level + MYMAX(0, lava_features_lim - 4) * 50;
107 tcave_cache = new float[csize.Y + 2];
111 MapgenValleys::~MapgenValleys()
115 delete noise_filler_depth;
116 delete noise_inter_valley_fill;
117 delete noise_inter_valley_slope;
119 delete noise_massive_caves;
120 delete noise_terrain_height;
121 delete noise_valley_depth;
122 delete noise_valley_profile;
124 delete[] tcave_cache;
128 MapgenValleysParams::MapgenValleysParams()
130 np_cave1 = NoiseParams(0, 12, v3f(61, 61, 61), 52534, 3, 0.5, 2.0);
131 np_cave2 = NoiseParams(0, 12, v3f(67, 67, 67), 10325, 3, 0.5, 2.0);
132 np_filler_depth = NoiseParams(0.f, 1.2f, v3f(256, 256, 256), 1605, 3, 0.5f, 2.f);
133 np_inter_valley_fill = NoiseParams(0.f, 1.f, v3f(256, 512, 256), 1993, 6, 0.8f, 2.f);
134 np_inter_valley_slope = NoiseParams(0.5f, 0.5f, v3f(128, 128, 128), 746, 1, 1.f, 2.f);
135 np_rivers = NoiseParams(0.f, 1.f, v3f(256, 256, 256), -6050, 5, 0.6f, 2.f);
136 np_massive_caves = NoiseParams(0.f, 1.f, v3f(768, 256, 768), 59033, 6, 0.63f, 2.f);
137 np_terrain_height = NoiseParams(-10.f, 50.f, v3f(1024, 1024, 1024), 5202, 6, 0.4f, 2.f);
138 np_valley_depth = NoiseParams(5.f, 4.f, v3f(512, 512, 512), -1914, 1, 1.f, 2.f);
139 np_valley_profile = NoiseParams(0.6f, 0.5f, v3f(512, 512, 512), 777, 1, 1.f, 2.f);
143 void MapgenValleysParams::readParams(const Settings *settings)
145 settings->getFlagStrNoEx("mgvalleys_spflags", spflags, flagdesc_mapgen_valleys);
146 settings->getU16NoEx("mgvalleys_altitude_chill", altitude_chill);
147 settings->getS16NoEx("mgvalleys_large_cave_depth", large_cave_depth);
148 settings->getU16NoEx("mgvalleys_lava_features", lava_features);
149 settings->getS16NoEx("mgvalleys_massive_cave_depth", massive_cave_depth);
150 settings->getU16NoEx("mgvalleys_river_depth", river_depth);
151 settings->getU16NoEx("mgvalleys_river_size", river_size);
152 settings->getU16NoEx("mgvalleys_water_features", water_features);
153 settings->getFloatNoEx("mgvalleys_cave_width", cave_width);
155 settings->getNoiseParams("mgvalleys_np_cave1", np_cave1);
156 settings->getNoiseParams("mgvalleys_np_cave2", np_cave2);
157 settings->getNoiseParams("mgvalleys_np_filler_depth", np_filler_depth);
158 settings->getNoiseParams("mgvalleys_np_inter_valley_fill", np_inter_valley_fill);
159 settings->getNoiseParams("mgvalleys_np_inter_valley_slope", np_inter_valley_slope);
160 settings->getNoiseParams("mgvalleys_np_rivers", np_rivers);
161 settings->getNoiseParams("mgvalleys_np_massive_caves", np_massive_caves);
162 settings->getNoiseParams("mgvalleys_np_terrain_height", np_terrain_height);
163 settings->getNoiseParams("mgvalleys_np_valley_depth", np_valley_depth);
164 settings->getNoiseParams("mgvalleys_np_valley_profile", np_valley_profile);
168 void MapgenValleysParams::writeParams(Settings *settings) const
170 settings->setFlagStr("mgvalleys_spflags", spflags, flagdesc_mapgen_valleys, U32_MAX);
171 settings->setU16("mgvalleys_altitude_chill", altitude_chill);
172 settings->setS16("mgvalleys_large_cave_depth", large_cave_depth);
173 settings->setU16("mgvalleys_lava_features", lava_features);
174 settings->setS16("mgvalleys_massive_cave_depth", massive_cave_depth);
175 settings->setU16("mgvalleys_river_depth", river_depth);
176 settings->setU16("mgvalleys_river_size", river_size);
177 settings->setU16("mgvalleys_water_features", water_features);
178 settings->setFloat("mgvalleys_cave_width", cave_width);
180 settings->setNoiseParams("mgvalleys_np_cave1", np_cave1);
181 settings->setNoiseParams("mgvalleys_np_cave2", np_cave2);
182 settings->setNoiseParams("mgvalleys_np_filler_depth", np_filler_depth);
183 settings->setNoiseParams("mgvalleys_np_inter_valley_fill", np_inter_valley_fill);
184 settings->setNoiseParams("mgvalleys_np_inter_valley_slope", np_inter_valley_slope);
185 settings->setNoiseParams("mgvalleys_np_rivers", np_rivers);
186 settings->setNoiseParams("mgvalleys_np_massive_caves", np_massive_caves);
187 settings->setNoiseParams("mgvalleys_np_terrain_height", np_terrain_height);
188 settings->setNoiseParams("mgvalleys_np_valley_depth", np_valley_depth);
189 settings->setNoiseParams("mgvalleys_np_valley_profile", np_valley_profile);
193 ///////////////////////////////////////
196 void MapgenValleys::makeChunk(BlockMakeData *data)
199 assert(data->vmanip);
200 assert(data->nodedef);
201 assert(data->blockpos_requested.X >= data->blockpos_min.X &&
202 data->blockpos_requested.Y >= data->blockpos_min.Y &&
203 data->blockpos_requested.Z >= data->blockpos_min.Z);
204 assert(data->blockpos_requested.X <= data->blockpos_max.X &&
205 data->blockpos_requested.Y <= data->blockpos_max.Y &&
206 data->blockpos_requested.Z <= data->blockpos_max.Z);
208 this->generating = true;
209 this->vm = data->vmanip;
210 this->ndef = data->nodedef;
212 //TimeTaker t("makeChunk");
214 v3s16 blockpos_min = data->blockpos_min;
215 v3s16 blockpos_max = data->blockpos_max;
216 node_min = blockpos_min * MAP_BLOCKSIZE;
217 node_max = (blockpos_max + v3s16(1, 1, 1)) * MAP_BLOCKSIZE - v3s16(1, 1, 1);
218 full_node_min = (blockpos_min - 1) * MAP_BLOCKSIZE;
219 full_node_max = (blockpos_max + 2) * MAP_BLOCKSIZE - v3s16(1, 1, 1);
221 blockseed = getBlockSeed2(full_node_min, seed);
223 // Generate biome noises. Note this must be executed strictly before
224 // generateTerrain, because generateTerrain depends on intermediate
225 // biome-related noises.
226 m_bgen->calcBiomeNoise(node_min);
228 // Generate noise maps and base terrain height.
229 // Modify heat and humidity maps.
232 // Generate base terrain with initial heightmaps
233 s16 stone_surface_max_y = generateTerrain();
235 // Recalculate heightmap
236 updateHeightmap(node_min, node_max);
238 // Place biome-specific nodes and build biomemap
239 MgStoneType stone_type = generateBiomes(water_level - 1);
242 if (flags & MG_CAVES)
243 generateCaves(stone_surface_max_y, large_cave_depth);
246 if ((flags & MG_DUNGEONS) && node_max.Y < 50)
247 generateDungeons(stone_surface_max_y, stone_type);
249 // Generate the registered decorations
250 if (flags & MG_DECORATIONS)
251 m_emerge->decomgr->placeAllDecos(this, blockseed,
252 node_min, node_max, water_level - 1);
254 // Generate the registered ores
255 m_emerge->oremgr->placeAllOres(this, blockseed,
256 node_min, node_max, water_level - 1);
258 // Sprinkle some dust on top after everything else was generated
261 //TimeTaker tll("liquid_lighting");
263 updateLiquid(&data->transforming_liquid, full_node_min, full_node_max);
265 if (flags & MG_LIGHT)
267 node_min - v3s16(0, 1, 0),
268 node_max + v3s16(0, 1, 0),
272 //mapgen_profiler->avg("liquid_lighting", tll.stop() / 1000.f);
273 //mapgen_profiler->avg("makeChunk", t.stop() / 1000.f);
275 this->generating = false;
279 // Populate the noise tables and do most of the
280 // calculation necessary to determine terrain height.
281 void MapgenValleys::calculateNoise()
283 //TimeTaker t("calculateNoise", NULL, PRECISION_MICRO);
286 int y = node_min.Y - 1;
289 //TimeTaker tcn("actualNoise");
291 noise_inter_valley_slope->perlinMap2D(x, z);
292 noise_rivers->perlinMap2D(x, z);
293 noise_terrain_height->perlinMap2D(x, z);
294 noise_valley_depth->perlinMap2D(x, z);
295 noise_valley_profile->perlinMap2D(x, z);
297 noise_inter_valley_fill->perlinMap3D(x, y, z);
299 //mapgen_profiler->avg("noisemaps", tcn.stop() / 1000.f);
301 float heat_offset = 0.f;
302 float humidity_scale = 1.f;
304 // Altitude chill tends to reduce the average heat.
305 if (use_altitude_chill)
308 // River humidity tends to increase the humidity range.
310 humidity_scale = 0.8f;
313 for (s32 index = 0; index < csize.X * csize.Z; index++) {
314 m_bgen->heatmap[index] += heat_offset;
315 m_bgen->humidmap[index] *= humidity_scale;
321 for (tn.z = node_min.Z; tn.z <= node_max.Z; tn.z++)
322 for (tn.x = node_min.X; tn.x <= node_max.X; tn.x++, index++) {
323 // The parameters that we actually need to generate terrain
324 // are passed by address (and the return value).
325 tn.terrain_height = noise_terrain_height->result[index];
326 // River noise is replaced with base terrain, which
327 // is basically the height of the water table.
328 tn.rivers = &noise_rivers->result[index];
329 // Valley depth noise is replaced with the valley
330 // number that represents the height of terrain
331 // over rivers and is used to determine about
332 // how close a river is for humidity calculation.
333 tn.valley = &noise_valley_depth->result[index];
334 tn.valley_profile = noise_valley_profile->result[index];
335 // Slope noise is replaced by the calculated slope
336 // which is used to get terrain height in the slow
337 // method, to create sharper mountains.
338 tn.slope = &noise_inter_valley_slope->result[index];
339 tn.inter_valley_fill = noise_inter_valley_fill->result[index];
341 // This is the actual terrain height.
342 float mount = terrainLevelFromNoise(&tn);
343 noise_terrain_height->result[index] = mount;
348 // This keeps us from having to maintain two similar sets of
349 // complicated code to determine ground level.
350 float MapgenValleys::terrainLevelFromNoise(TerrainNoise *tn)
352 // The square function changes the behaviour of this noise:
353 // very often small, and sometimes very high.
354 float valley_d = MYSQUARE(*tn->valley);
356 // valley_d is here because terrain is generally higher where valleys
357 // are deep (mountains). base represents the height of the
358 // rivers, most of the surface is above.
359 float base = tn->terrain_height + valley_d;
361 // "river" represents the distance from the river, in arbitrary units.
362 float river = fabs(*tn->rivers) - river_size_factor;
364 // Use the curve of the function 1-exp(-(x/a)^2) to model valleys.
365 // Making "a" vary (0 < a <= 1) changes the shape of the valleys.
366 // Try it with a geometry software !
367 // (here x = "river" and a = valley_profile).
368 // "valley" represents the height of the terrain, from the rivers.
370 float t = river / tn->valley_profile;
371 *tn->valley = valley_d * (1.f - exp(- MYSQUARE(t)));
374 // approximate height of the terrain at this point
375 float mount = base + *tn->valley;
377 *tn->slope *= *tn->valley;
379 // Rivers are placed where "river" is negative, so where the original
380 // noise value is close to zero.
381 // Base ground is returned as rivers since it's basically the water table.
384 // Use the the function -sqrt(1-x^2) which models a circle.
387 float t = river / river_size_factor + 1;
388 depth = (river_depth_bed * sqrt(MYMAX(0, 1.f - MYSQUARE(t))));
391 // base - depth : height of the bottom of the river
392 // water_level - 3 : don't make rivers below 3 nodes under the surface
393 // We use three because that's as low as the swamp biomes go.
394 // There is no logical equivalent to this using rangelim.
395 mount = MYMIN(MYMAX(base - depth, (float)(water_level - 3)), mount);
397 // Slope has no influence on rivers.
405 // This avoids duplicating the code in terrainLevelFromNoise, adding
406 // only the final step of terrain generation without a noise map.
407 float MapgenValleys::adjustedTerrainLevelFromNoise(TerrainNoise *tn)
409 float mount = terrainLevelFromNoise(tn);
410 s16 y_start = myround(mount);
412 for (s16 y = y_start; y <= y_start + 1000; y++) {
413 float fill = NoisePerlin3D(&noise_inter_valley_fill->np, tn->x, y, tn->z, seed);
415 if (fill * *tn->slope < y - mount) {
416 mount = MYMAX(y - 1, mount);
425 int MapgenValleys::getSpawnLevelAtPoint(v2s16 p)
427 // Check to make sure this isn't a request for a location in a river.
428 float rivers = NoisePerlin2D(&noise_rivers->np, p.X, p.Y, seed);
429 if (fabs(rivers) < river_size_factor)
430 return MAX_MAP_GENERATION_LIMIT; // Unsuitable spawn point
432 s16 level_at_point = terrainLevelAtPoint(p.X, p.Y);
433 if (level_at_point <= water_level ||
434 level_at_point > water_level + 32)
435 return MAX_MAP_GENERATION_LIMIT; // Unsuitable spawn point
437 return level_at_point;
441 float MapgenValleys::terrainLevelAtPoint(s16 x, s16 z)
445 float rivers = NoisePerlin2D(&noise_rivers->np, x, z, seed);
446 float valley = NoisePerlin2D(&noise_valley_depth->np, x, z, seed);
447 float inter_valley_slope = NoisePerlin2D(&noise_inter_valley_slope->np, x, z, seed);
451 tn.terrain_height = NoisePerlin2D(&noise_terrain_height->np, x, z, seed);
454 tn.valley_profile = NoisePerlin2D(&noise_valley_profile->np, x, z, seed);
455 tn.slope = &inter_valley_slope;
456 tn.inter_valley_fill = 0.f;
458 return adjustedTerrainLevelFromNoise(&tn);
462 int MapgenValleys::generateTerrain()
464 // Raising this reduces the rate of evaporation.
465 static const float evaporation = 300.f;
467 static const float humidity_dropoff = 4.f;
468 // constant to convert altitude chill (compatible with lua) to heat
469 static const float alt_to_heat = 20.f;
470 // humidity reduction by altitude
471 static const float alt_to_humid = 10.f;
473 MapNode n_air(CONTENT_AIR);
474 MapNode n_river_water(c_river_water_source);
475 MapNode n_stone(c_stone);
476 MapNode n_water(c_water_source);
478 v3s16 em = vm->m_area.getExtent();
479 s16 surface_max_y = -MAX_MAP_GENERATION_LIMIT;
482 for (s16 z = node_min.Z; z <= node_max.Z; z++)
483 for (s16 x = node_min.X; x <= node_max.X; x++, index_2d++) {
484 float river_y = noise_rivers->result[index_2d];
485 float surface_y = noise_terrain_height->result[index_2d];
486 float slope = noise_inter_valley_slope->result[index_2d];
487 float t_heat = m_bgen->heatmap[index_2d];
489 heightmap[index_2d] = -MAX_MAP_GENERATION_LIMIT;
491 if (surface_y > surface_max_y)
492 surface_max_y = ceil(surface_y);
495 // Derive heat from (base) altitude. This will be most correct
496 // at rivers, since other surface heights may vary below.
497 if (use_altitude_chill && (surface_y > 0.f || river_y > 0.f))
498 t_heat -= alt_to_heat * MYMAX(surface_y, river_y) / altitude_chill;
500 // If humidity is low or heat is high, lower the water table.
501 float delta = m_bgen->humidmap[index_2d] - 50.f;
503 float t_evap = (t_heat - 32.f) / evaporation;
504 river_y += delta * MYMAX(t_evap, 0.08f);
508 u32 index_3d = (z - node_min.Z) * zstride_1u1d + (x - node_min.X);
509 u32 index_data = vm->m_area.index(x, node_min.Y - 1, z);
511 // Mapgens concern themselves with stone and water.
512 for (s16 y = node_min.Y - 1; y <= node_max.Y + 1; y++) {
513 if (vm->m_data[index_data].getContent() == CONTENT_IGNORE) {
514 float fill = noise_inter_valley_fill->result[index_3d];
515 float surface_delta = (float)y - surface_y;
516 bool river = y + 1 < river_y;
518 if (slope * fill > surface_delta) {
520 vm->m_data[index_data] = n_stone;
521 if (y > heightmap[index_2d])
522 heightmap[index_2d] = y;
523 if (y > surface_max_y)
525 } else if (y <= water_level) {
527 vm->m_data[index_data] = n_water;
530 vm->m_data[index_data] = n_river_water;
532 vm->m_data[index_data] = n_air;
536 vm->m_area.add_y(em, index_data, 1);
540 if (heightmap[index_2d] == -MAX_MAP_GENERATION_LIMIT) {
541 s16 surface_y_int = myround(surface_y);
542 if (surface_y_int > node_max.Y + 1 || surface_y_int < node_min.Y - 1) {
543 // If surface_y is outside the chunk, it's good enough.
544 heightmap[index_2d] = surface_y_int;
546 // If the ground is outside of this chunk, but surface_y
547 // is within the chunk, give a value outside.
548 heightmap[index_2d] = node_min.Y - 2;
553 // Use base ground (water table) in a riverbed, to
554 // avoid an unnatural rise in humidity.
555 float t_alt = MYMAX(noise_rivers->result[index_2d], (float)heightmap[index_2d]);
556 float humid = m_bgen->humidmap[index_2d];
557 float water_depth = (t_alt - river_y) / humidity_dropoff;
558 humid *= 1.f + pow(0.5f, MYMAX(water_depth, 1.f));
560 // Reduce humidity with altitude (ignoring riverbeds).
561 // This is similar to the lua version's seawater adjustment,
562 // but doesn't increase the base humidity, which causes
563 // problems with the default biomes.
565 humid -= alt_to_humid * t_alt / altitude_chill;
567 m_bgen->humidmap[index_2d] = humid;
570 // Assign the heat adjusted by any changed altitudes.
571 // The altitude will change about half the time.
572 if (use_altitude_chill) {
573 // ground height ignoring riverbeds
574 float t_alt = MYMAX(noise_rivers->result[index_2d], (float)heightmap[index_2d]);
575 if (humid_rivers && heightmap[index_2d] == (s16)myround(surface_y))
576 // The altitude hasn't changed. Use the first result.
577 m_bgen->heatmap[index_2d] = t_heat;
578 else if (t_alt > 0.f)
579 m_bgen->heatmap[index_2d] -= alt_to_heat * t_alt / altitude_chill;
583 return surface_max_y;
586 void MapgenValleys::generateCaves(s16 max_stone_y, s16 large_cave_depth)
588 if (max_stone_y < node_min.Y)
591 noise_cave1->perlinMap3D(node_min.X, node_min.Y - 1, node_min.Z);
592 noise_cave2->perlinMap3D(node_min.X, node_min.Y - 1, node_min.Z);
594 PseudoRandom ps(blockseed + 72202);
596 MapNode n_air(CONTENT_AIR);
597 MapNode n_lava(c_lava_source);
598 MapNode n_water(c_river_water_source);
600 v3s16 em = vm->m_area.getExtent();
602 // Cave blend distance near YMIN, YMAX
603 const float massive_cave_blend = 128.f;
604 // noise threshold for massive caves
605 const float massive_cave_threshold = 0.6f;
606 // mct: 1 = small rare caves, 0.5 1/3rd ground volume, 0 = 1/2 ground volume.
608 float yblmin = -mapgen_limit + massive_cave_blend * 1.5f;
609 float yblmax = massive_cave_depth - massive_cave_blend * 1.5f;
610 bool made_a_big_one = false;
612 // Cache the tcave values as they only vary by altitude.
613 if (node_max.Y <= massive_cave_depth) {
614 noise_massive_caves->perlinMap3D(node_min.X, node_min.Y - 1, node_min.Z);
616 for (s16 y = node_min.Y - 1; y <= node_max.Y; y++) {
617 float tcave = massive_cave_threshold;
620 float t = (yblmin - y) / massive_cave_blend;
621 tcave += MYSQUARE(t);
622 } else if (y > yblmax) {
623 float t = (y - yblmax) / massive_cave_blend;
624 tcave += MYSQUARE(t);
627 tcave_cache[y - node_min.Y + 1] = tcave;
631 // lava_depth varies between one and ten as you approach
632 // the bottom of the world.
633 s16 lava_depth = ceil((lava_max_height - node_min.Y + 1) * 10.f / mapgen_limit);
634 // This allows random lava spawns to be less common at the surface.
635 s16 lava_chance = MYCUBE(lava_features_lim) * lava_depth;
636 // water_depth varies between ten and one on the way down.
637 s16 water_depth = ceil((mapgen_limit - abs(node_min.Y) + 1) * 10.f / mapgen_limit);
638 // This allows random water spawns to be more common at the surface.
639 s16 water_chance = MYCUBE(water_features_lim) * water_depth;
641 // Reduce the odds of overflows even further.
642 if (node_max.Y > water_level) {
648 for (s16 z = node_min.Z; z <= node_max.Z; z++)
649 for (s16 x = node_min.X; x <= node_max.X; x++, index_2d++) {
650 Biome *biome = (Biome *)m_bmgr->getRaw(biomemap[index_2d]);
651 bool tunnel_air_above = false;
652 bool is_under_river = false;
653 bool underground = false;
654 u32 index_data = vm->m_area.index(x, node_max.Y, z);
655 u32 index_3d = (z - node_min.Z) * zstride_1d + csize.Y * ystride + (x - node_min.X);
657 // Dig caves on down loop to check for air above.
658 // Don't excavate the overgenerated stone at node_max.Y + 1,
659 // this creates a 'roof' over the tunnel, preventing light in
660 // tunnels at mapchunk borders when generating mapchunks upwards.
661 // This 'roof' is removed when the mapchunk above is generated.
662 for (s16 y = node_max.Y; y >= node_min.Y - 1; y--,
664 vm->m_area.add_y(em, index_data, -1)) {
666 float terrain = noise_terrain_height->result[index_2d];
669 if (y > terrain + 10)
671 else 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);