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-rw-r--r--src/mapgen/mapgen_valleys.cpp368
1 files changed, 126 insertions, 242 deletions
diff --git a/src/mapgen/mapgen_valleys.cpp b/src/mapgen/mapgen_valleys.cpp
index 5f9267875..a27a31201 100644
--- a/src/mapgen/mapgen_valleys.cpp
+++ b/src/mapgen/mapgen_valleys.cpp
@@ -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"
@@ -53,9 +54,6 @@ FlagDesc flagdesc_mapgen_valleys[] = {
};
-////////////////////////////////////////////////////////////////////////////////
-
-
MapgenValleys::MapgenValleys(int mapgenid, MapgenValleysParams *params,
EmergeManager *emerge)
: MapgenBasic(mapgenid, params, emerge)
@@ -63,8 +61,6 @@ MapgenValleys::MapgenValleys(int mapgenid, MapgenValleysParams *params,
// 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;
river_depth_bed = params->river_depth + 1.0f;
@@ -95,8 +91,6 @@ MapgenValleys::MapgenValleys(int mapgenid, MapgenValleysParams *params,
MapgenBasic::np_cave1 = params->np_cave1;
MapgenBasic::np_cave2 = params->np_cave2;
MapgenBasic::np_cavern = params->np_cavern;
-
- humidity_adjust = bp->np_humidity.offset - 50.0f;
}
@@ -185,9 +179,6 @@ void MapgenValleysParams::writeParams(Settings *settings) const
}
-////////////////////////////////////////////////////////////////////////////////
-
-
void MapgenValleys::makeChunk(BlockMakeData *data)
{
// Pre-conditions
@@ -220,19 +211,16 @@ 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) {
@@ -281,244 +269,151 @@ 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 (spflags & MGVALLEYS_ALT_CHILL)
- heat_offset = 5.0f;
- // River humidity tends to increase the humidity range.
- if (spflags & MGVALLEYS_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)
-{
- float mount = terrainLevelFromNoise(tn);
- float result = mount;
- s16 y_start = myround(mount);
- float fill =
- NoisePerlin3D(&noise_inter_valley_fill->np, tn->x, y_start, tn->z, seed);
- bool is_ground = fill * *tn->slope >= y_start - mount;
- s16 search_direction = is_ground ? 1 : -1;
-
- for (s16 i = 1; i <= 1000; i++) {
- s16 y = y_start + i * search_direction;
- fill =
- NoisePerlin3D(&noise_inter_valley_fill->np, tn->x, y, tn->z, seed);
-
- bool was_ground = is_ground;
- is_ground = fill * *tn->slope >= y - mount;
- if (is_ground)
- result = y;
- if (is_ground != was_ground)
- break;
- }
-
- return result;
-}
-
-
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
-
- // +1 to account for biome dust that can be 1 node deep
- return level_at_point + 1;
-}
-
-
-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);
+ // 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;
+ }
+ }
+ // 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);
+ 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 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;
+ }
// Optionally vary river depth according to heat and humidity
if (spflags & MGVALLEYS_VARY_RIVER_DEPTH) {
- float heat = ((spflags & MGVALLEYS_ALT_CHILL) &&
- (surface_y > 0.0f || river_y > 0.0f)) ?
- t_heat - alt_to_heat *
- std::fmax(surface_y, river_y) / altitude_chill :
+ 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 = (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
@@ -529,26 +424,13 @@ 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(noise_rivers->result[index_2d],
- (float)heightmap[index_2d]);
- float water_depth = (t_alt - river_y) / humidity_dropoff;
+ 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));
}
@@ -556,21 +438,23 @@ int MapgenValleys::generateTerrain()
// Optionally decrease humidity with altitude
if (spflags & MGVALLEYS_ALT_DRY) {
// Ground height ignoring riverbeds
- float t_alt = std::fmax(noise_rivers->result[index_2d],
- (float)heightmap[index_2d]);
- 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->humidmap[index_2d] -=
- alt_to_humid * t_alt / altitude_chill;
+ (t_alt - water_level) * 10.0f / 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 (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;
}
}