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+/*
+Minetest Valleys C
+Copyright (C) 2016-2017 Duane Robertson <duane@duanerobertson.com>
+Copyright (C) 2016-2017 paramat
+
+Based on Valleys Mapgen by Gael de Sailly
+ (https://forum.minetest.net/viewtopic.php?f=9&t=11430)
+and mapgen_v7, mapgen_flat by kwolekr and paramat.
+
+Licensing changed by permission of Gael de Sailly.
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU Lesser General Public License as published by
+the Free Software Foundation; either version 2.1 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+GNU Lesser General Public License for more details.
+
+You should have received a copy of the GNU Lesser General Public License along
+with this program; if not, write to the Free Software Foundation, Inc.,
+51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+*/
+
+#include "mapgen.h"
+#include "voxel.h"
+#include "noise.h"
+#include "mapblock.h"
+#include "mapnode.h"
+#include "map.h"
+#include "nodedef.h"
+#include "voxelalgorithms.h"
+#include "settings.h" // For g_settings
+#include "emerge.h"
+#include "dungeongen.h"
+#include "mg_biome.h"
+#include "mg_ore.h"
+#include "mg_decoration.h"
+#include "mapgen_valleys.h"
+#include "cavegen.h"
+
+
+//#undef NDEBUG
+//#include "assert.h"
+
+//#include "util/timetaker.h"
+//#include "profiler.h"
+
+
+//static Profiler mapgen_prof;
+//Profiler *mapgen_profiler = &mapgen_prof;
+
+static FlagDesc flagdesc_mapgen_valleys[] = {
+ {"altitude_chill", MGVALLEYS_ALT_CHILL},
+ {"humid_rivers", MGVALLEYS_HUMID_RIVERS},
+ {NULL, 0}
+};
+
+///////////////////////////////////////////////////////////////////////////////
+
+
+MapgenValleys::MapgenValleys(int mapgenid, MapgenValleysParams *params, EmergeManager *emerge)
+ : MapgenBasic(mapgenid, params, emerge)
+{
+ // NOTE: MapgenValleys has a hard dependency on BiomeGenOriginal
+ m_bgen = (BiomeGenOriginal *)biomegen;
+
+ BiomeParamsOriginal *bp = (BiomeParamsOriginal *)params->bparams;
+
+ spflags = params->spflags;
+ altitude_chill = params->altitude_chill;
+ large_cave_depth = params->large_cave_depth;
+ lava_features_lim = rangelim(params->lava_features, 0, 10);
+ massive_cave_depth = params->massive_cave_depth;
+ river_depth_bed = params->river_depth + 1.f;
+ river_size_factor = params->river_size / 100.f;
+ water_features_lim = rangelim(params->water_features, 0, 10);
+ cave_width = params->cave_width;
+
+ //// 2D Terrain noise
+ noise_filler_depth = new Noise(&params->np_filler_depth, seed, csize.X, csize.Z);
+ noise_inter_valley_slope = new Noise(&params->np_inter_valley_slope, seed, csize.X, csize.Z);
+ noise_rivers = new Noise(&params->np_rivers, seed, csize.X, csize.Z);
+ noise_terrain_height = new Noise(&params->np_terrain_height, seed, csize.X, csize.Z);
+ noise_valley_depth = new Noise(&params->np_valley_depth, seed, csize.X, csize.Z);
+ noise_valley_profile = new Noise(&params->np_valley_profile, seed, csize.X, csize.Z);
+
+ //// 3D Terrain noise
+ // 1-up 1-down overgeneration
+ noise_inter_valley_fill = new Noise(&params->np_inter_valley_fill, seed, csize.X, csize.Y + 2, csize.Z);
+ // 1-down overgeneraion
+ noise_cave1 = new Noise(&params->np_cave1, seed, csize.X, csize.Y + 1, csize.Z);
+ noise_cave2 = new Noise(&params->np_cave2, seed, csize.X, csize.Y + 1, csize.Z);
+ noise_massive_caves = new Noise(&params->np_massive_caves, seed, csize.X, csize.Y + 1, csize.Z);
+
+ humid_rivers = (spflags & MGVALLEYS_HUMID_RIVERS);
+ use_altitude_chill = (spflags & MGVALLEYS_ALT_CHILL);
+ humidity_adjust = bp->np_humidity.offset - 50.f;
+
+ // a small chance of overflows if the settings are very high
+ cave_water_max_height = water_level + MYMAX(0, water_features_lim - 4) * 50;
+ lava_max_height = water_level + MYMAX(0, lava_features_lim - 4) * 50;
+
+ tcave_cache = new float[csize.Y + 2];
+}
+
+
+MapgenValleys::~MapgenValleys()
+{
+ delete noise_cave1;
+ delete noise_cave2;
+ delete noise_filler_depth;
+ delete noise_inter_valley_fill;
+ delete noise_inter_valley_slope;
+ delete noise_rivers;
+ delete noise_massive_caves;
+ delete noise_terrain_height;
+ delete noise_valley_depth;
+ delete noise_valley_profile;
+
+ delete[] tcave_cache;
+}
+
+
+MapgenValleysParams::MapgenValleysParams():
+ np_cave1 (0, 12, v3f(61, 61, 61), 52534, 3, 0.5, 2.0),
+ np_cave2 (0, 12, v3f(67, 67, 67), 10325, 3, 0.5, 2.0),
+ np_filler_depth (0.f, 1.2f, v3f(256, 256, 256), 1605, 3, 0.5f, 2.f),
+ np_inter_valley_fill (0.f, 1.f, v3f(256, 512, 256), 1993, 6, 0.8f, 2.f),
+ np_inter_valley_slope (0.5f, 0.5f, v3f(128, 128, 128), 746, 1, 1.f, 2.f),
+ np_rivers (0.f, 1.f, v3f(256, 256, 256), -6050, 5, 0.6f, 2.f),
+ np_massive_caves (0.f, 1.f, v3f(768, 256, 768), 59033, 6, 0.63f, 2.f),
+ np_terrain_height (-10.f, 50.f, v3f(1024, 1024, 1024), 5202, 6, 0.4f, 2.f),
+ np_valley_depth (5.f, 4.f, v3f(512, 512, 512), -1914, 1, 1.f, 2.f),
+ np_valley_profile (0.6f, 0.5f, v3f(512, 512, 512), 777, 1, 1.f, 2.f)
+{
+}
+
+
+void MapgenValleysParams::readParams(const Settings *settings)
+{
+ settings->getFlagStrNoEx("mgvalleys_spflags", spflags, flagdesc_mapgen_valleys);
+ settings->getU16NoEx("mgvalleys_altitude_chill", altitude_chill);
+ settings->getS16NoEx("mgvalleys_large_cave_depth", large_cave_depth);
+ settings->getU16NoEx("mgvalleys_lava_features", lava_features);
+ settings->getS16NoEx("mgvalleys_massive_cave_depth", massive_cave_depth);
+ settings->getU16NoEx("mgvalleys_river_depth", river_depth);
+ settings->getU16NoEx("mgvalleys_river_size", river_size);
+ settings->getU16NoEx("mgvalleys_water_features", water_features);
+ settings->getFloatNoEx("mgvalleys_cave_width", cave_width);
+
+ settings->getNoiseParams("mgvalleys_np_cave1", np_cave1);
+ settings->getNoiseParams("mgvalleys_np_cave2", np_cave2);
+ settings->getNoiseParams("mgvalleys_np_filler_depth", np_filler_depth);
+ settings->getNoiseParams("mgvalleys_np_inter_valley_fill", np_inter_valley_fill);
+ settings->getNoiseParams("mgvalleys_np_inter_valley_slope", np_inter_valley_slope);
+ settings->getNoiseParams("mgvalleys_np_rivers", np_rivers);
+ settings->getNoiseParams("mgvalleys_np_massive_caves", np_massive_caves);
+ settings->getNoiseParams("mgvalleys_np_terrain_height", np_terrain_height);
+ settings->getNoiseParams("mgvalleys_np_valley_depth", np_valley_depth);
+ settings->getNoiseParams("mgvalleys_np_valley_profile", np_valley_profile);
+}
+
+
+void MapgenValleysParams::writeParams(Settings *settings) const
+{
+ settings->setFlagStr("mgvalleys_spflags", spflags, flagdesc_mapgen_valleys, U32_MAX);
+ settings->setU16("mgvalleys_altitude_chill", altitude_chill);
+ settings->setS16("mgvalleys_large_cave_depth", large_cave_depth);
+ settings->setU16("mgvalleys_lava_features", lava_features);
+ settings->setS16("mgvalleys_massive_cave_depth", massive_cave_depth);
+ settings->setU16("mgvalleys_river_depth", river_depth);
+ settings->setU16("mgvalleys_river_size", river_size);
+ settings->setU16("mgvalleys_water_features", water_features);
+ settings->setFloat("mgvalleys_cave_width", cave_width);
+
+ settings->setNoiseParams("mgvalleys_np_cave1", np_cave1);
+ settings->setNoiseParams("mgvalleys_np_cave2", np_cave2);
+ settings->setNoiseParams("mgvalleys_np_filler_depth", np_filler_depth);
+ settings->setNoiseParams("mgvalleys_np_inter_valley_fill", np_inter_valley_fill);
+ settings->setNoiseParams("mgvalleys_np_inter_valley_slope", np_inter_valley_slope);
+ settings->setNoiseParams("mgvalleys_np_rivers", np_rivers);
+ settings->setNoiseParams("mgvalleys_np_massive_caves", np_massive_caves);
+ settings->setNoiseParams("mgvalleys_np_terrain_height", np_terrain_height);
+ settings->setNoiseParams("mgvalleys_np_valley_depth", np_valley_depth);
+ settings->setNoiseParams("mgvalleys_np_valley_profile", np_valley_profile);
+}
+
+
+///////////////////////////////////////
+
+
+void MapgenValleys::makeChunk(BlockMakeData *data)
+{
+ // Pre-conditions
+ assert(data->vmanip);
+ assert(data->nodedef);
+ assert(data->blockpos_requested.X >= data->blockpos_min.X &&
+ data->blockpos_requested.Y >= data->blockpos_min.Y &&
+ data->blockpos_requested.Z >= data->blockpos_min.Z);
+ assert(data->blockpos_requested.X <= data->blockpos_max.X &&
+ data->blockpos_requested.Y <= data->blockpos_max.Y &&
+ data->blockpos_requested.Z <= data->blockpos_max.Z);
+
+ this->generating = true;
+ this->vm = data->vmanip;
+ this->ndef = data->nodedef;
+
+ //TimeTaker t("makeChunk");
+
+ v3s16 blockpos_min = data->blockpos_min;
+ v3s16 blockpos_max = data->blockpos_max;
+ node_min = blockpos_min * MAP_BLOCKSIZE;
+ node_max = (blockpos_max + v3s16(1, 1, 1)) * MAP_BLOCKSIZE - v3s16(1, 1, 1);
+ full_node_min = (blockpos_min - 1) * MAP_BLOCKSIZE;
+ full_node_max = (blockpos_max + 2) * MAP_BLOCKSIZE - v3s16(1, 1, 1);
+
+ blockseed = getBlockSeed2(full_node_min, seed);
+
+ // Generate biome noises. Note this must be executed strictly before
+ // generateTerrain, because generateTerrain depends on intermediate
+ // biome-related noises.
+ m_bgen->calcBiomeNoise(node_min);
+
+ // Generate noise maps and base terrain height.
+ // Modify heat and humidity maps.
+ calculateNoise();
+
+ // Generate base terrain with initial heightmaps
+ s16 stone_surface_max_y = generateTerrain();
+
+ // Recalculate heightmap
+ updateHeightmap(node_min, node_max);
+
+ // Place biome-specific nodes and build biomemap
+ MgStoneType mgstone_type;
+ content_t biome_stone;
+ generateBiomes(&mgstone_type, &biome_stone);
+
+ // Cave creation.
+ if (flags & MG_CAVES)
+ generateCaves(stone_surface_max_y, large_cave_depth);
+
+ // Dungeon creation
+ if ((flags & MG_DUNGEONS) && node_max.Y < 50)
+ generateDungeons(stone_surface_max_y, mgstone_type, biome_stone);
+
+ // Generate the registered decorations
+ if (flags & MG_DECORATIONS)
+ m_emerge->decomgr->placeAllDecos(this, blockseed, node_min, node_max);
+
+ // Generate the registered ores
+ m_emerge->oremgr->placeAllOres(this, blockseed, node_min, node_max);
+
+ // Sprinkle some dust on top after everything else was generated
+ dustTopNodes();
+
+ //TimeTaker tll("liquid_lighting");
+
+ updateLiquid(&data->transforming_liquid, full_node_min, full_node_max);
+
+ if (flags & MG_LIGHT)
+ calcLighting(
+ node_min - v3s16(0, 1, 0),
+ node_max + v3s16(0, 1, 0),
+ full_node_min,
+ full_node_max);
+
+ //mapgen_profiler->avg("liquid_lighting", tll.stop() / 1000.f);
+ //mapgen_profiler->avg("makeChunk", t.stop() / 1000.f);
+
+ this->generating = false;
+}
+
+
+// Populate the noise tables and do most of the
+// calculation necessary to determine terrain height.
+void MapgenValleys::calculateNoise()
+{
+ //TimeTaker t("calculateNoise", NULL, PRECISION_MICRO);
+
+ int x = node_min.X;
+ int y = node_min.Y - 1;
+ int z = node_min.Z;
+
+ //TimeTaker tcn("actualNoise");
+
+ noise_inter_valley_slope->perlinMap2D(x, z);
+ noise_rivers->perlinMap2D(x, z);
+ noise_terrain_height->perlinMap2D(x, z);
+ noise_valley_depth->perlinMap2D(x, z);
+ noise_valley_profile->perlinMap2D(x, z);
+
+ noise_inter_valley_fill->perlinMap3D(x, y, z);
+
+ //mapgen_profiler->avg("noisemaps", tcn.stop() / 1000.f);
+
+ float heat_offset = 0.f;
+ float humidity_scale = 1.f;
+
+ // Altitude chill tends to reduce the average heat.
+ if (use_altitude_chill)
+ heat_offset = 5.f;
+
+ // River humidity tends to increase the humidity range.
+ if (humid_rivers) {
+ humidity_scale = 0.8f;
+ }
+
+ for (s32 index = 0; index < csize.X * csize.Z; index++) {
+ m_bgen->heatmap[index] += heat_offset;
+ m_bgen->humidmap[index] *= humidity_scale;
+ }
+
+ TerrainNoise tn;
+
+ u32 index = 0;
+ for (tn.z = node_min.Z; tn.z <= node_max.Z; tn.z++)
+ for (tn.x = node_min.X; tn.x <= node_max.X; tn.x++, index++) {
+ // The parameters that we actually need to generate terrain
+ // are passed by address (and the return value).
+ tn.terrain_height = noise_terrain_height->result[index];
+ // River noise is replaced with base terrain, which
+ // is basically the height of the water table.
+ tn.rivers = &noise_rivers->result[index];
+ // Valley depth noise is replaced with the valley
+ // number that represents the height of terrain
+ // over rivers and is used to determine about
+ // how close a river is for humidity calculation.
+ tn.valley = &noise_valley_depth->result[index];
+ tn.valley_profile = noise_valley_profile->result[index];
+ // Slope noise is replaced by the calculated slope
+ // which is used to get terrain height in the slow
+ // method, to create sharper mountains.
+ tn.slope = &noise_inter_valley_slope->result[index];
+ tn.inter_valley_fill = noise_inter_valley_fill->result[index];
+
+ // This is the actual terrain height.
+ float mount = terrainLevelFromNoise(&tn);
+ noise_terrain_height->result[index] = mount;
+ }
+}
+
+
+// This keeps us from having to maintain two similar sets of
+// complicated code to determine ground level.
+float MapgenValleys::terrainLevelFromNoise(TerrainNoise *tn)
+{
+ // The square function changes the behaviour of this noise:
+ // very often small, and sometimes very high.
+ float valley_d = MYSQUARE(*tn->valley);
+
+ // valley_d is here because terrain is generally higher where valleys
+ // are deep (mountains). base represents the height of the
+ // rivers, most of the surface is above.
+ float base = tn->terrain_height + valley_d;
+
+ // "river" represents the distance from the river, in arbitrary units.
+ float river = fabs(*tn->rivers) - river_size_factor;
+
+ // Use the curve of the function 1-exp(-(x/a)^2) to model valleys.
+ // Making "a" vary (0 < a <= 1) changes the shape of the valleys.
+ // Try it with a geometry software !
+ // (here x = "river" and a = valley_profile).
+ // "valley" represents the height of the terrain, from the rivers.
+ {
+ float t = river / tn->valley_profile;
+ *tn->valley = valley_d * (1.f - exp(- MYSQUARE(t)));
+ }
+
+ // approximate height of the terrain at this point
+ float mount = base + *tn->valley;
+
+ *tn->slope *= *tn->valley;
+
+ // Rivers are placed where "river" is negative, so where the original
+ // noise value is close to zero.
+ // Base ground is returned as rivers since it's basically the water table.
+ *tn->rivers = base;
+ if (river < 0.f) {
+ // Use the the function -sqrt(1-x^2) which models a circle.
+ float depth;
+ {
+ float t = river / river_size_factor + 1;
+ depth = (river_depth_bed * sqrt(MYMAX(0, 1.f - MYSQUARE(t))));
+ }
+
+ // base - depth : height of the bottom of the river
+ // water_level - 3 : don't make rivers below 3 nodes under the surface
+ // We use three because that's as low as the swamp biomes go.
+ // There is no logical equivalent to this using rangelim.
+ mount = MYMIN(MYMAX(base - depth, (float)(water_level - 3)), mount);
+
+ // Slope has no influence on rivers.
+ *tn->slope = 0.f;
+ }
+
+ return mount;
+}
+
+
+// This avoids duplicating the code in terrainLevelFromNoise, adding
+// only the final step of terrain generation without a noise map.
+float MapgenValleys::adjustedTerrainLevelFromNoise(TerrainNoise *tn)
+{
+ float mount = terrainLevelFromNoise(tn);
+ s16 y_start = myround(mount);
+
+ for (s16 y = y_start; y <= y_start + 1000; y++) {
+ float fill = NoisePerlin3D(&noise_inter_valley_fill->np, tn->x, y, tn->z, seed);
+
+ if (fill * *tn->slope < y - mount) {
+ mount = MYMAX(y - 1, mount);
+ break;
+ }
+ }
+
+ return mount;
+}
+
+
+int MapgenValleys::getSpawnLevelAtPoint(v2s16 p)
+{
+ // Check to make sure this isn't a request for a location in a river.
+ float rivers = NoisePerlin2D(&noise_rivers->np, p.X, p.Y, seed);
+ if (fabs(rivers) < river_size_factor)
+ return MAX_MAP_GENERATION_LIMIT; // Unsuitable spawn point
+
+ s16 level_at_point = terrainLevelAtPoint(p.X, p.Y);
+ if (level_at_point <= water_level ||
+ level_at_point > water_level + 32)
+ return MAX_MAP_GENERATION_LIMIT; // Unsuitable spawn point
+
+ return level_at_point;
+}
+
+
+float MapgenValleys::terrainLevelAtPoint(s16 x, s16 z)
+{
+ TerrainNoise tn;
+
+ float rivers = NoisePerlin2D(&noise_rivers->np, x, z, seed);
+ float valley = NoisePerlin2D(&noise_valley_depth->np, x, z, seed);
+ float inter_valley_slope = NoisePerlin2D(&noise_inter_valley_slope->np, x, z, seed);
+
+ tn.x = x;
+ tn.z = z;
+ tn.terrain_height = NoisePerlin2D(&noise_terrain_height->np, x, z, seed);
+ tn.rivers = &rivers;
+ tn.valley = &valley;
+ tn.valley_profile = NoisePerlin2D(&noise_valley_profile->np, x, z, seed);
+ tn.slope = &inter_valley_slope;
+ tn.inter_valley_fill = 0.f;
+
+ return adjustedTerrainLevelFromNoise(&tn);
+}
+
+
+int MapgenValleys::generateTerrain()
+{
+ // Raising this reduces the rate of evaporation.
+ static const float evaporation = 300.f;
+ // from the lua
+ static const float humidity_dropoff = 4.f;
+ // constant to convert altitude chill (compatible with lua) to heat
+ static const float alt_to_heat = 20.f;
+ // humidity reduction by altitude
+ static const float alt_to_humid = 10.f;
+
+ MapNode n_air(CONTENT_AIR);
+ MapNode n_river_water(c_river_water_source);
+ MapNode n_stone(c_stone);
+ MapNode n_water(c_water_source);
+
+ const v3s16 &em = vm->m_area.getExtent();
+ s16 surface_max_y = -MAX_MAP_GENERATION_LIMIT;
+ u32 index_2d = 0;
+
+ for (s16 z = node_min.Z; z <= node_max.Z; z++)
+ for (s16 x = node_min.X; x <= node_max.X; x++, index_2d++) {
+ float river_y = noise_rivers->result[index_2d];
+ float surface_y = noise_terrain_height->result[index_2d];
+ float slope = noise_inter_valley_slope->result[index_2d];
+ float t_heat = m_bgen->heatmap[index_2d];
+
+ heightmap[index_2d] = -MAX_MAP_GENERATION_LIMIT;
+
+ if (surface_y > surface_max_y)
+ surface_max_y = ceil(surface_y);
+
+ if (humid_rivers) {
+ // Derive heat from (base) altitude. This will be most correct
+ // at rivers, since other surface heights may vary below.
+ if (use_altitude_chill && (surface_y > 0.f || river_y > 0.f))
+ t_heat -= alt_to_heat * MYMAX(surface_y, river_y) / altitude_chill;
+
+ // If humidity is low or heat is high, lower the water table.
+ float delta = m_bgen->humidmap[index_2d] - 50.f;
+ if (delta < 0.f) {
+ float t_evap = (t_heat - 32.f) / evaporation;
+ river_y += delta * MYMAX(t_evap, 0.08f);
+ }
+ }
+
+ u32 index_3d = (z - node_min.Z) * zstride_1u1d + (x - node_min.X);
+ u32 index_data = vm->m_area.index(x, node_min.Y - 1, z);
+
+ // Mapgens concern themselves with stone and water.
+ for (s16 y = node_min.Y - 1; y <= node_max.Y + 1; y++) {
+ if (vm->m_data[index_data].getContent() == CONTENT_IGNORE) {
+ float fill = noise_inter_valley_fill->result[index_3d];
+ float surface_delta = (float)y - surface_y;
+ bool river = y + 1 < river_y;
+
+ if (slope * fill > surface_delta) {
+ // ground
+ vm->m_data[index_data] = n_stone;
+ if (y > heightmap[index_2d])
+ heightmap[index_2d] = y;
+ if (y > surface_max_y)
+ surface_max_y = y;
+ } else if (y <= water_level) {
+ // sea
+ vm->m_data[index_data] = n_water;
+ } else if (river) {
+ // river
+ vm->m_data[index_data] = n_river_water;
+ } else { // air
+ vm->m_data[index_data] = n_air;
+ }
+ }
+
+ vm->m_area.add_y(em, index_data, 1);
+ index_3d += ystride;
+ }
+
+ if (heightmap[index_2d] == -MAX_MAP_GENERATION_LIMIT) {
+ s16 surface_y_int = myround(surface_y);
+ if (surface_y_int > node_max.Y + 1 || surface_y_int < node_min.Y - 1) {
+ // If surface_y is outside the chunk, it's good enough.
+ heightmap[index_2d] = surface_y_int;
+ } else {
+ // If the ground is outside of this chunk, but surface_y
+ // is within the chunk, give a value outside.
+ heightmap[index_2d] = node_min.Y - 2;
+ }
+ }
+
+ if (humid_rivers) {
+ // Use base ground (water table) in a riverbed, to
+ // avoid an unnatural rise in humidity.
+ float t_alt = MYMAX(noise_rivers->result[index_2d], (float)heightmap[index_2d]);
+ float humid = m_bgen->humidmap[index_2d];
+ float water_depth = (t_alt - river_y) / humidity_dropoff;
+ humid *= 1.f + pow(0.5f, MYMAX(water_depth, 1.f));
+
+ // Reduce humidity with altitude (ignoring riverbeds).
+ // This is similar to the lua version's seawater adjustment,
+ // but doesn't increase the base humidity, which causes
+ // problems with the default biomes.
+ if (t_alt > 0.f)
+ humid -= alt_to_humid * t_alt / altitude_chill;
+
+ m_bgen->humidmap[index_2d] = humid;
+ }
+
+ // Assign the heat adjusted by any changed altitudes.
+ // The altitude will change about half the time.
+ if (use_altitude_chill) {
+ // ground height ignoring riverbeds
+ float t_alt = MYMAX(noise_rivers->result[index_2d], (float)heightmap[index_2d]);
+ if (humid_rivers && heightmap[index_2d] == (s16)myround(surface_y))
+ // The altitude hasn't changed. Use the first result.
+ m_bgen->heatmap[index_2d] = t_heat;
+ else if (t_alt > 0.f)
+ m_bgen->heatmap[index_2d] -= alt_to_heat * t_alt / altitude_chill;
+ }
+ }
+
+ return surface_max_y;
+}
+
+void MapgenValleys::generateCaves(s16 max_stone_y, s16 large_cave_depth)
+{
+ if (max_stone_y < node_min.Y)
+ return;
+
+ noise_cave1->perlinMap3D(node_min.X, node_min.Y - 1, node_min.Z);
+ noise_cave2->perlinMap3D(node_min.X, node_min.Y - 1, node_min.Z);
+
+ PseudoRandom ps(blockseed + 72202);
+
+ MapNode n_air(CONTENT_AIR);
+ MapNode n_lava(c_lava_source);
+ MapNode n_water(c_river_water_source);
+
+ const v3s16 &em = vm->m_area.getExtent();
+
+ // Cave blend distance near YMIN, YMAX
+ const float massive_cave_blend = 128.f;
+ // noise threshold for massive caves
+ const float massive_cave_threshold = 0.6f;
+ // mct: 1 = small rare caves, 0.5 1/3rd ground volume, 0 = 1/2 ground volume.
+
+ float yblmin = -mapgen_limit + massive_cave_blend * 1.5f;
+ float yblmax = massive_cave_depth - massive_cave_blend * 1.5f;
+ bool made_a_big_one = false;
+
+ // Cache the tcave values as they only vary by altitude.
+ if (node_max.Y <= massive_cave_depth) {
+ noise_massive_caves->perlinMap3D(node_min.X, node_min.Y - 1, node_min.Z);
+
+ for (s16 y = node_min.Y - 1; y <= node_max.Y; y++) {
+ float tcave = massive_cave_threshold;
+
+ if (y < yblmin) {
+ float t = (yblmin - y) / massive_cave_blend;
+ tcave += MYSQUARE(t);
+ } else if (y > yblmax) {
+ float t = (y - yblmax) / massive_cave_blend;
+ tcave += MYSQUARE(t);
+ }
+
+ tcave_cache[y - node_min.Y + 1] = tcave;
+ }
+ }
+
+ // lava_depth varies between one and ten as you approach
+ // the bottom of the world.
+ s16 lava_depth = ceil((lava_max_height - node_min.Y + 1) * 10.f / mapgen_limit);
+ // This allows random lava spawns to be less common at the surface.
+ s16 lava_chance = MYCUBE(lava_features_lim) * lava_depth;
+ // water_depth varies between ten and one on the way down.
+ s16 water_depth = ceil((mapgen_limit - abs(node_min.Y) + 1) * 10.f / mapgen_limit);
+ // This allows random water spawns to be more common at the surface.
+ s16 water_chance = MYCUBE(water_features_lim) * water_depth;
+
+ // Reduce the odds of overflows even further.
+ if (node_max.Y > water_level) {
+ lava_chance /= 3;
+ water_chance /= 3;
+ }
+
+ u32 index_2d = 0;
+ for (s16 z = node_min.Z; z <= node_max.Z; z++)
+ for (s16 x = node_min.X; x <= node_max.X; x++, index_2d++) {
+ Biome *biome = (Biome *)m_bmgr->getRaw(biomemap[index_2d]);
+ bool tunnel_air_above = false;
+ bool is_under_river = false;
+ bool underground = false;
+ u32 index_data = vm->m_area.index(x, node_max.Y, z);
+ u32 index_3d = (z - node_min.Z) * zstride_1d + csize.Y * ystride + (x - node_min.X);
+
+ // Dig caves on down loop to check for air above.
+ // Don't excavate the overgenerated stone at node_max.Y + 1,
+ // this creates a 'roof' over the tunnel, preventing light in
+ // tunnels at mapchunk borders when generating mapchunks upwards.
+ // This 'roof' is removed when the mapchunk above is generated.
+ for (s16 y = node_max.Y; y >= node_min.Y - 1; y--,
+ index_3d -= ystride,
+ vm->m_area.add_y(em, index_data, -1)) {
+
+ float terrain = noise_terrain_height->result[index_2d];
+
+ // Saves some time.
+ if (y > terrain + 10)
+ continue;
+
+ if (y < terrain - 40)
+ underground = true;
+
+ // Dig massive caves.
+ if (node_max.Y <= massive_cave_depth
+ && noise_massive_caves->result[index_3d]
+ > tcave_cache[y - node_min.Y + 1]) {
+ vm->m_data[index_data] = n_air;
+ made_a_big_one = true;
+ continue;
+ }
+
+ content_t c = vm->m_data[index_data].getContent();
+ // Detect river water to place riverbed nodes in tunnels
+ if (c == biome->c_river_water)
+ is_under_river = true;
+
+ float d1 = contour(noise_cave1->result[index_3d]);
+ float d2 = contour(noise_cave2->result[index_3d]);
+
+ if (d1 * d2 > cave_width && ndef->get(c).is_ground_content) {
+ // in a tunnel
+ vm->m_data[index_data] = n_air;
+ tunnel_air_above = true;
+ } else if (c == biome->c_filler || c == biome->c_stone) {
+ if (tunnel_air_above) {
+ // at the tunnel floor
+ s16 sr = ps.range(0, 39);
+ u32 j = index_data;
+ vm->m_area.add_y(em, j, 1);
+
+ if (sr > terrain - y) {
+ // Put biome nodes in tunnels near the surface
+ if (is_under_river)
+ vm->m_data[index_data] = MapNode(biome->c_riverbed);
+ else if (underground)
+ vm->m_data[index_data] = MapNode(biome->c_filler);
+ else
+ vm->m_data[index_data] = MapNode(biome->c_top);
+ } else if (sr < 3 && underground) {
+ sr = abs(ps.next());
+ if (lava_features_lim > 0 && y <= lava_max_height
+ && c == biome->c_stone && sr < lava_chance)
+ vm->m_data[j] = n_lava;
+
+ sr -= lava_chance;
+
+ // If sr < 0 then we should have already placed lava --
+ // don't immediately dump water on it.
+ if (water_features_lim > 0 && y <= cave_water_max_height
+ && sr >= 0 && sr < water_chance)
+ vm->m_data[j] = n_water;
+ }
+ }
+
+ tunnel_air_above = false;
+ underground = true;
+ } else {
+ tunnel_air_above = false;
+ }
+ }
+ }
+
+ if (node_max.Y <= large_cave_depth && !made_a_big_one) {
+ u32 bruises_count = ps.range(0, 2);
+ for (u32 i = 0; i < bruises_count; i++) {
+ CavesRandomWalk cave(ndef, &gennotify, seed, water_level,
+ c_water_source, c_lava_source, lava_max_height);
+
+ cave.makeCave(vm, node_min, node_max, &ps, true, max_stone_y, heightmap);
+ }
+ }
+}