]> git.lizzy.rs Git - dragonfireclient.git/blobdiff - src/mapgen/mapgen_valleys.cpp
Merge pull request #59 from PrairieAstronomer/readme_irrlicht_change
[dragonfireclient.git] / src / mapgen / mapgen_valleys.cpp
index 341ce3137c26c7e4c04037536c33e4fa579332d3..80a99b1f0fd728c16d4a905cdeb2dd5f338ae014 100644 (file)
@@ -1,7 +1,7 @@
 /*
 Minetest
-Copyright (C) 2016-2018 Duane Robertson <duane@duanerobertson.com>
-Copyright (C) 2016-2018 paramat
+Copyright (C) 2016-2019 Duane Robertson <duane@duanerobertson.com>
+Copyright (C) 2016-2019 paramat
 
 Based on Valleys Mapgen by Gael de Sailly
 (https://forum.minetest.net/viewtopic.php?f=9&t=11430)
@@ -24,6 +24,7 @@ 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"
@@ -44,25 +45,22 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include <cmath>
 
 
-static FlagDesc flagdesc_mapgen_valleys[] = {
-       {"altitude_chill", MGVALLEYS_ALT_CHILL},
-       {"humid_rivers",   MGVALLEYS_HUMID_RIVERS},
-       {NULL,             0}
+FlagDesc flagdesc_mapgen_valleys[] = {
+       {"altitude_chill",   MGVALLEYS_ALT_CHILL},
+       {"humid_rivers",     MGVALLEYS_HUMID_RIVERS},
+       {"vary_river_depth", MGVALLEYS_VARY_RIVER_DEPTH},
+       {"altitude_dry",     MGVALLEYS_ALT_DRY},
+       {NULL,               0}
 };
 
 
-////////////////////////////////////////////////////////////////////////////////
-
-
-MapgenValleys::MapgenValleys(int mapgenid, MapgenValleysParams *params,
-       EmergeManager *emerge)
-       : MapgenBasic(mapgenid, params, emerge)
+MapgenValleys::MapgenValleys(MapgenValleysParams *params, EmergeParams *emerge)
+       : MapgenBasic(MAPGEN_VALLEYS, params, emerge)
 {
-       // NOTE: MapgenValleys has a hard dependency on BiomeGenOriginal
+       FATAL_ERROR_IF(biomegen->getType() != BIOMEGEN_ORIGINAL,
+               "MapgenValleys has a hard dependency on BiomeGenOriginal");
        m_bgen = (BiomeGenOriginal *)biomegen;
 
-       BiomeParamsOriginal *bp = (BiomeParamsOriginal *)params->bparams;
-
        spflags            = params->spflags;
        altitude_chill     = params->altitude_chill;
        river_depth_bed    = params->river_depth + 1.0f;
@@ -70,7 +68,11 @@ MapgenValleys::MapgenValleys(int mapgenid, MapgenValleysParams *params,
 
        cave_width         = params->cave_width;
        large_cave_depth   = params->large_cave_depth;
-       lava_depth         = params->lava_depth;
+       small_cave_num_min = params->small_cave_num_min;
+       small_cave_num_max = params->small_cave_num_max;
+       large_cave_num_min = params->large_cave_num_min;
+       large_cave_num_max = params->large_cave_num_max;
+       large_cave_flooded = params->large_cave_flooded;
        cavern_limit       = params->cavern_limit;
        cavern_taper       = params->cavern_taper;
        cavern_threshold   = params->cavern_threshold;
@@ -90,13 +92,10 @@ MapgenValleys::MapgenValleys(int mapgenid, MapgenValleysParams *params,
        noise_inter_valley_fill = new Noise(&params->np_inter_valley_fill,
                seed, csize.X, csize.Y + 2, csize.Z);
        // 1-down overgeneraion
-       MapgenBasic::np_cave1   = params->np_cave1;
-       MapgenBasic::np_cave2   = params->np_cave2;
-       MapgenBasic::np_cavern  = params->np_cavern;
-
-       humid_rivers       = (spflags & MGVALLEYS_HUMID_RIVERS);
-       use_altitude_chill = (spflags & MGVALLEYS_ALT_CHILL);
-       humidity_adjust    = bp->np_humidity.offset - 50.0f;
+       MapgenBasic::np_cave1    = params->np_cave1;
+       MapgenBasic::np_cave2    = params->np_cave2;
+       MapgenBasic::np_cavern   = params->np_cavern;
+       MapgenBasic::np_dungeons = params->np_dungeons;
 }
 
 
@@ -122,25 +121,30 @@ MapgenValleysParams::MapgenValleysParams():
        np_valley_profile     (0.6,   0.50, v3f(512,  512,  512),  777,   1, 1.0,  2.0),
        np_cave1              (0.0,   12.0, v3f(61,   61,   61),   52534, 3, 0.5,  2.0),
        np_cave2              (0.0,   12.0, v3f(67,   67,   67),   10325, 3, 0.5,  2.0),
-       np_cavern             (0.0,   1.0,  v3f(768,  256,  768),  59033, 6, 0.63, 2.0)
+       np_cavern             (0.0,   1.0,  v3f(768,  256,  768),  59033, 6, 0.63, 2.0),
+       np_dungeons           (0.9,   0.5,  v3f(500,  500,  500),  0,     2, 0.8,  2.0)
 {
 }
 
 
 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->getS16NoEx("mgvalleys_lava_depth",         lava_depth);
-       settings->getU16NoEx("mgvalleys_river_depth",        river_depth);
-       settings->getU16NoEx("mgvalleys_river_size",         river_size);
-       settings->getFloatNoEx("mgvalleys_cave_width",       cave_width);
-       settings->getS16NoEx("mgvalleys_cavern_limit",       cavern_limit);
-       settings->getS16NoEx("mgvalleys_cavern_taper",       cavern_taper);
-       settings->getFloatNoEx("mgvalleys_cavern_threshold", cavern_threshold);
-       settings->getS16NoEx("mgvalleys_dungeon_ymin",       dungeon_ymin);
-       settings->getS16NoEx("mgvalleys_dungeon_ymax",       dungeon_ymax);
+       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_small_cave_num_min",   small_cave_num_min);
+       settings->getU16NoEx("mgvalleys_small_cave_num_max",   small_cave_num_max);
+       settings->getU16NoEx("mgvalleys_large_cave_num_min",   large_cave_num_min);
+       settings->getU16NoEx("mgvalleys_large_cave_num_max",   large_cave_num_max);
+       settings->getFloatNoEx("mgvalleys_large_cave_flooded", large_cave_flooded);
+       settings->getU16NoEx("mgvalleys_river_depth",          river_depth);
+       settings->getU16NoEx("mgvalleys_river_size",           river_size);
+       settings->getFloatNoEx("mgvalleys_cave_width",         cave_width);
+       settings->getS16NoEx("mgvalleys_cavern_limit",         cavern_limit);
+       settings->getS16NoEx("mgvalleys_cavern_taper",         cavern_taper);
+       settings->getFloatNoEx("mgvalleys_cavern_threshold",   cavern_threshold);
+       settings->getS16NoEx("mgvalleys_dungeon_ymin",         dungeon_ymin);
+       settings->getS16NoEx("mgvalleys_dungeon_ymax",         dungeon_ymax);
 
        settings->getNoiseParams("mgvalleys_np_filler_depth",       np_filler_depth);
        settings->getNoiseParams("mgvalleys_np_inter_valley_fill",  np_inter_valley_fill);
@@ -153,23 +157,28 @@ void MapgenValleysParams::readParams(const Settings *settings)
        settings->getNoiseParams("mgvalleys_np_cave1",              np_cave1);
        settings->getNoiseParams("mgvalleys_np_cave2",              np_cave2);
        settings->getNoiseParams("mgvalleys_np_cavern",             np_cavern);
+       settings->getNoiseParams("mgvalleys_np_dungeons",           np_dungeons);
 }
 
 
 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->setS16("mgvalleys_lava_depth",         lava_depth);
-       settings->setU16("mgvalleys_river_depth",        river_depth);
-       settings->setU16("mgvalleys_river_size",         river_size);
-       settings->setFloat("mgvalleys_cave_width",       cave_width);
-       settings->setS16("mgvalleys_cavern_limit",       cavern_limit);
-       settings->setS16("mgvalleys_cavern_taper",       cavern_taper);
-       settings->setFloat("mgvalleys_cavern_threshold", cavern_threshold);
-       settings->setS16("mgvalleys_dungeon_ymin",       dungeon_ymin);
-       settings->setS16("mgvalleys_dungeon_ymax",       dungeon_ymax);
+       settings->setFlagStr("mgvalleys_spflags", spflags, flagdesc_mapgen_valleys);
+       settings->setU16("mgvalleys_altitude_chill",       altitude_chill);
+       settings->setS16("mgvalleys_large_cave_depth",     large_cave_depth);
+       settings->setU16("mgvalleys_small_cave_num_min",   small_cave_num_min);
+       settings->setU16("mgvalleys_small_cave_num_max",   small_cave_num_max);
+       settings->setU16("mgvalleys_large_cave_num_min",   large_cave_num_min);
+       settings->setU16("mgvalleys_large_cave_num_max",   large_cave_num_max);
+       settings->setFloat("mgvalleys_large_cave_flooded", large_cave_flooded);
+       settings->setU16("mgvalleys_river_depth",          river_depth);
+       settings->setU16("mgvalleys_river_size",           river_size);
+       settings->setFloat("mgvalleys_cave_width",         cave_width);
+       settings->setS16("mgvalleys_cavern_limit",         cavern_limit);
+       settings->setS16("mgvalleys_cavern_taper",         cavern_taper);
+       settings->setFloat("mgvalleys_cavern_threshold",   cavern_threshold);
+       settings->setS16("mgvalleys_dungeon_ymin",         dungeon_ymin);
+       settings->setS16("mgvalleys_dungeon_ymax",         dungeon_ymax);
 
        settings->setNoiseParams("mgvalleys_np_filler_depth",       np_filler_depth);
        settings->setNoiseParams("mgvalleys_np_inter_valley_fill",  np_inter_valley_fill);
@@ -182,10 +191,19 @@ void MapgenValleysParams::writeParams(Settings *settings) const
        settings->setNoiseParams("mgvalleys_np_cave1",              np_cave1);
        settings->setNoiseParams("mgvalleys_np_cave2",              np_cave2);
        settings->setNoiseParams("mgvalleys_np_cavern",             np_cavern);
+       settings->setNoiseParams("mgvalleys_np_dungeons",           np_dungeons);
+}
+
+
+void MapgenValleysParams::setDefaultSettings(Settings *settings)
+{
+       settings->setDefault("mgvalleys_spflags", flagdesc_mapgen_valleys,
+               MGVALLEYS_ALT_CHILL | MGVALLEYS_HUMID_RIVERS |
+               MGVALLEYS_VARY_RIVER_DEPTH | MGVALLEYS_ALT_DRY);
 }
 
 
-////////////////////////////////////////////////////////////////////////////////
+/////////////////////////////////////////////////////////////////
 
 
 void MapgenValleys::makeChunk(BlockMakeData *data)
@@ -193,12 +211,6 @@ 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);
 
        //TimeTaker t("makeChunk");
 
@@ -220,19 +232,16 @@ void MapgenValleys::makeChunk(BlockMakeData *data)
        // 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
+       // Generate terrain
        s16 stone_surface_max_y = generateTerrain();
 
-       // Recalculate heightmap
+       // Create heightmap
        updateHeightmap(node_min, node_max);
 
        // Place biome-specific nodes and build biomemap
-       if (flags & MG_BIOMES)
+       if (flags & MG_BIOMES) {
                generateBiomes();
+       }
 
        // Generate tunnels, caverns and large randomwalk caves
        if (flags & MG_CAVES) {
@@ -253,18 +262,18 @@ void MapgenValleys::makeChunk(BlockMakeData *data)
                        generateCavesRandomWalk(stone_surface_max_y, large_cave_depth);
        }
 
+       // Generate the registered ores
+       if (flags & MG_ORES)
+               m_emerge->oremgr->placeAllOres(this, blockseed, node_min, node_max);
+
        // Dungeon creation
-       if ((flags & MG_DUNGEONS) && full_node_min.Y >= dungeon_ymin &&
-                       full_node_max.Y <= dungeon_ymax)
+       if (flags & MG_DUNGEONS)
                generateDungeons(stone_surface_max_y);
 
        // 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
        if (flags & MG_BIOMES)
                dustTopNodes();
@@ -281,235 +290,151 @@ void MapgenValleys::makeChunk(BlockMakeData *data)
 }
 
 
-void MapgenValleys::calculateNoise()
-{
-       int x = node_min.X;
-       int y = node_min.Y - 1;
-       int z = node_min.Z;
-
-       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);
-
-       float heat_offset = 0.0f;
-       float humidity_scale = 1.0f;
-       // Altitude chill tends to reduce the average heat.
-       if (use_altitude_chill)
-               heat_offset = 5.0f;
-       // 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 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;
-       }
-}
-
-
-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
-       float river = std::fabs(*tn->rivers) - river_size_factor;
-
-       // Use the curve of the function 1-exp(-(x/a)^2) to model valleys.
-       // "valley" represents the height of the terrain, from the rivers.
-       float tv = std::fmax(river / tn->valley_profile, 0.0f);
-       *tn->valley = valley_d * (1.0f - std::exp(-MYSQUARE(tv)));
-
-       // Approximate height of the terrain at this point
-       float mount = base + *tn->valley;
-
-       *tn->slope *= *tn->valley;
-
-       // Base ground is returned as rivers since it's basically the water table.
-       *tn->rivers = base;
-
-       // Rivers are placed where "river" is negative, so where the original noise
-       // value is close to zero.
-       if (river < 0.0f) {
-               // Use the the function -sqrt(1-x^2) which models a circle
-               float tr = river / river_size_factor + 1.0f;
-               float depth = (river_depth_bed *
-                       std::sqrt(std::fmax(0.0f, 1.0f - MYSQUARE(tr))));
-
-               // 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 =
-                       std::fmin(std::fmax(base - depth, (float)(water_level - 3)), mount);
-
-               // Slope has no influence on rivers
-               *tn->slope = 0.0f;
-       }
-
-       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)
+int MapgenValleys::getSpawnLevelAtPoint(v2s16 p)
 {
-       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 = std::fmax((float)(y - 1), mount);
-                       break;
+       // Check if in a river channel
+       float n_rivers = NoisePerlin2D(&noise_rivers->np, p.X, p.Y, seed);
+       if (std::fabs(n_rivers) <= river_size_factor)
+               // Unsuitable spawn point
+               return MAX_MAP_GENERATION_LIMIT;
+
+       float n_slope          = NoisePerlin2D(&noise_inter_valley_slope->np, p.X, p.Y, seed);
+       float n_terrain_height = NoisePerlin2D(&noise_terrain_height->np, p.X, p.Y, seed);
+       float n_valley         = NoisePerlin2D(&noise_valley_depth->np, p.X, p.Y, seed);
+       float n_valley_profile = NoisePerlin2D(&noise_valley_profile->np, p.X, p.Y, seed);
+
+       float valley_d = n_valley * n_valley;
+       float base = n_terrain_height + valley_d;
+       float river = std::fabs(n_rivers) - river_size_factor;
+       float tv = std::fmax(river / n_valley_profile, 0.0f);
+       float valley_h = valley_d * (1.0f - std::exp(-tv * tv));
+       float surface_y = base + valley_h;
+       float slope = n_slope * valley_h;
+       float river_y = base - 1.0f;
+
+       // Raising the maximum spawn level above 'water_level + 16' is necessary for custom
+       // parameters that set average terrain level much higher than water_level.
+       s16 max_spawn_y = std::fmax(
+               noise_terrain_height->np.offset +
+               noise_valley_depth->np.offset * noise_valley_depth->np.offset,
+               water_level + 16);
+
+       // Starting spawn search at max_spawn_y + 128 ensures 128 nodes of open
+       // space above spawn position. Avoids spawning in possibly sealed voids.
+       for (s16 y = max_spawn_y + 128; y >= water_level; y--) {
+               float n_fill = NoisePerlin3D(&noise_inter_valley_fill->np, p.X, y, p.Y, seed);
+               float surface_delta = (float)y - surface_y;
+               float density = slope * n_fill - surface_delta;
+
+               if (density > 0.0f) {  // If solid
+                       // Sometimes surface level is below river water level in places that are not
+                       // river channels.
+                       if (y < water_level || y > max_spawn_y || y < (s16)river_y)
+                               // Unsuitable spawn point
+                               return MAX_MAP_GENERATION_LIMIT;
+
+                       // y + 2 because y is surface and due to biome 'dust' nodes.
+                       return y + 2;
                }
        }
-
-       return mount;
-}
-
-
-int MapgenValleys::getSpawnLevelAtPoint(v2s16 p)
-{
-       // Check if in a river
-       float rivers = NoisePerlin2D(&noise_rivers->np, p.X, p.Y, seed);
-       if (std::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 + 16)
-               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 = 0.0f;
-
-       return adjustedTerrainLevelFromNoise(&tn);
+       // Unsuitable spawn position, no ground found
+       return MAX_MAP_GENERATION_LIMIT;
 }
 
 
 int MapgenValleys::generateTerrain()
 {
-       // Raising this reduces the rate of evaporation
-       static const float evaporation = 300.0f;
-       static const float humidity_dropoff = 4.0f;
-       // Constant to convert altitude chill to heat
-       static const float alt_to_heat = 20.0f;
-       // Humidity reduction by altitude
-       static const float alt_to_humid = 10.0f;
-
        MapNode n_air(CONTENT_AIR);
        MapNode n_river_water(c_river_water_source);
        MapNode n_stone(c_stone);
        MapNode n_water(c_water_source);
 
+       noise_inter_valley_slope->perlinMap2D(node_min.X, node_min.Z);
+       noise_rivers->perlinMap2D(node_min.X, node_min.Z);
+       noise_terrain_height->perlinMap2D(node_min.X, node_min.Z);
+       noise_valley_depth->perlinMap2D(node_min.X, node_min.Z);
+       noise_valley_profile->perlinMap2D(node_min.X, node_min.Z);
+
+       noise_inter_valley_fill->perlinMap3D(node_min.X, node_min.Y - 1, node_min.Z);
+
        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 = std::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 > 0.0f || river_y > 0.0f))
-                               t_heat -= alt_to_heat *
-                                       std::fmax(surface_y, river_y) / altitude_chill;
+               float n_slope          = noise_inter_valley_slope->result[index_2d];
+               float n_rivers         = noise_rivers->result[index_2d];
+               float n_terrain_height = noise_terrain_height->result[index_2d];
+               float n_valley         = noise_valley_depth->result[index_2d];
+               float n_valley_profile = noise_valley_profile->result[index_2d];
+
+               float valley_d = n_valley * n_valley;
+               // 'base' represents the level of the river banks
+               float base = n_terrain_height + valley_d;
+               // 'river' represents the distance from the river edge
+               float river = std::fabs(n_rivers) - river_size_factor;
+               // Use the curve of the function 1-exp(-(x/a)^2) to model valleys.
+               // 'valley_h' represents the height of the terrain, from the rivers.
+               float tv = std::fmax(river / n_valley_profile, 0.0f);
+               float valley_h = valley_d * (1.0f - std::exp(-tv * tv));
+               // Approximate height of the terrain
+               float surface_y = base + valley_h;
+               float slope = n_slope * valley_h;
+               // River water surface is 1 node below river banks
+               float river_y = base - 1.0f;
+
+               // Rivers are placed where 'river' is negative
+               if (river < 0.0f) {
+                       // Use the function -sqrt(1-x^2) which models a circle
+                       float tr = river / river_size_factor + 1.0f;
+                       float depth = (river_depth_bed *
+                               std::sqrt(std::fmax(0.0f, 1.0f - tr * tr)));
+                       // There is no logical equivalent to this using rangelim
+                       surface_y = std::fmin(
+                               std::fmax(base - depth, (float)(water_level - 3)),
+                               surface_y);
+                       slope = 0.0f;
+               }
 
-                       // If humidity is low or heat is high, lower the water table
+               // Optionally vary river depth according to heat and humidity
+               if (spflags & MGVALLEYS_VARY_RIVER_DEPTH) {
+                       float t_heat = m_bgen->heatmap[index_2d];
+                       float heat = (spflags & MGVALLEYS_ALT_CHILL) ?
+                               // Match heat value calculated below in
+                               // 'Optionally decrease heat with altitude'.
+                               // In rivers, 'ground height ignoring riverbeds' is 'base'.
+                               // As this only affects river water we can assume y > water_level.
+                               t_heat + 5.0f - (base - water_level) * 20.0f / altitude_chill :
+                               t_heat;
                        float delta = m_bgen->humidmap[index_2d] - 50.0f;
                        if (delta < 0.0f) {
-                               float t_evap = (t_heat - 32.0f) / evaporation;
+                               float t_evap = (heat - 32.0f) / 300.0f;
                                river_y += delta * std::fmax(t_evap, 0.08f);
                        }
                }
 
+               // Highest solid node in column
+               s16 column_max_y = surface_y;
                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);
 
                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 n_fill = noise_inter_valley_fill->result[index_3d];
                                float surface_delta = (float)y - surface_y;
-                               bool river = y < river_y - 1;
+                               // Density = density noise + density gradient
+                               float density = slope * n_fill - surface_delta;
 
-                               if (slope * fill > surface_delta) {
+                               if (density > 0.0f) {
                                        vm->m_data[index_data] = n_stone; // Stone
-                                       if (y > heightmap[index_2d])
-                                               heightmap[index_2d] = y;
                                        if (y > surface_max_y)
                                                surface_max_y = y;
+                                       if (y > column_max_y)
+                                               column_max_y = y;
                                } else if (y <= water_level) {
                                        vm->m_data[index_data] = n_water; // Water
-                               } else if (river) {
+                               } else if (y <= (s16)river_y) {
                                        vm->m_data[index_data] = n_river_water; // River water
                                } else {
                                        vm->m_data[index_data] = n_air; // Air
@@ -520,49 +445,37 @@ int MapgenValleys::generateTerrain()
                        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;
-                       }
+               // Optionally increase humidity around rivers
+               if (spflags & MGVALLEYS_HUMID_RIVERS) {
+                       // Compensate to avoid increasing average humidity
+                       m_bgen->humidmap[index_2d] *= 0.8f;
+                       // Ground height ignoring riverbeds
+                       float t_alt = std::fmax(base, (float)column_max_y);
+                       float water_depth = (t_alt - base) / 4.0f;
+                       m_bgen->humidmap[index_2d] *=
+                               1.0f + std::pow(0.5f, std::fmax(water_depth, 1.0f));
                }
 
-               if (humid_rivers) {
-                       // Use base ground (water table) in a riverbed, to avoid an
-                       // unnatural rise in humidity.
-                       float t_alt = std::fmax(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 *= 1.0f + std::pow(0.5f, std::fmax(water_depth, 1.0f));
-
-                       // Reduce humidity with altitude (ignoring riverbeds)
-                       if (t_alt > 0.0f)
-                               humid -= alt_to_humid * t_alt / altitude_chill;
-
-                       m_bgen->humidmap[index_2d] = humid;
+               // Optionally decrease humidity with altitude
+               if (spflags & MGVALLEYS_ALT_DRY) {
+                       // Ground height ignoring riverbeds
+                       float t_alt = std::fmax(base, (float)column_max_y);
+                       // Only decrease above water_level
+                       if (t_alt > water_level)
+                               m_bgen->humidmap[index_2d] -=
+                                       (t_alt - water_level) * 10.0f / altitude_chill;
                }
 
-               // Assign the heat adjusted by any changed altitudes.
-               // The altitude will change about half the time.
-               if (use_altitude_chill) {
+               // Optionally decrease heat with altitude
+               if (spflags & MGVALLEYS_ALT_CHILL) {
+                       // Compensate to avoid reducing the average heat
+                       m_bgen->heatmap[index_2d] += 5.0f;
                        // Ground height ignoring riverbeds
-                       float t_alt = std::fmax(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 > 0.0f)
+                       float t_alt = std::fmax(base, (float)column_max_y);
+                       // Only decrease above water_level
+                       if (t_alt > water_level)
                                m_bgen->heatmap[index_2d] -=
-                                       alt_to_heat * t_alt / altitude_chill;
+                                       (t_alt - water_level) * 20.0f / altitude_chill;
                }
        }