Files
VoxelEngine/World/WorldGen/VoronoiCells.cs
MDietermann e034d10339 feat(world-gen): larger biomes, smooth height blending, capped mountains; centralize tunables in Configuration
Terrain feel: biome regions ~10x larger (Voronoi cell size 96->960); terrain height now eases across biome borders via a Voronoi distance blend (smooth, and ~25x cheaper than the old 169-sample box blur); mountains capped to ~2/3 world height and gentled (ridged amplitude/frequency lowered), snow line lowered to match.

Centralization: ~27 world-gen/render tuning constants (biome amplitudes & frequencies, climate-noise frequencies/octaves, biome-selection thresholds, blend width, cell size, filler depth, snow line, camera near plane, spawn offset, overlay scale) hoisted from scattered literals into a region-organized, fully-commented Configuration. Configuration is threaded into NoiseSource, the biomes, BiomeRegistry, BiomeMap (+Classify), TerrainSampler, WorldGenerator (+BlockAt filler depth), and Camera via Player. Defaults equal the prior values, so generation is unchanged; worldgen tests updated for the new constructor signatures.
2026-06-03 16:27:06 +02:00

101 lines
3.4 KiB
C#

namespace VoxelEngine.World.WorldGen;
// A jittered-grid Voronoi partition. Pure integer-hash based, fully deterministic.
public sealed class VoronoiCells
{
public readonly record struct Cell(int Id, float CenterX, float CenterZ);
private readonly int _seed;
private readonly float _cellSize;
public VoronoiCells(int seed, float cellSize)
{
this._seed = seed;
this._cellSize = cellSize;
}
public Cell Nearest(float x, float z)
{
int gx = (int)MathF.Floor(x / this._cellSize);
int gz = (int)MathF.Floor(z / this._cellSize);
float bestDist = float.MaxValue;
int bestId = 0;
float bestCx = 0f, bestCz = 0f;
for (int oz = -1; oz <= 1; oz++)
for (int ox = -1; ox <= 1; ox++)
{
int cgx = gx + ox;
int cgz = gz + oz;
float jitterX = Jitter(cgx, cgz, this._seed);
float jitterZ = Jitter(cgx, cgz, this._seed + 9871);
float cx = (cgx + jitterX) * this._cellSize;
float cz = (cgz + jitterZ) * this._cellSize;
float dx = cx - x, dz = cz - z;
float dist = dx * dx + dz * dz;
if (dist < bestDist)
{
bestDist = dist;
bestId = (int)Hash(cgx, cgz, this._seed);
bestCx = cx;
bestCz = cz;
}
}
return new Cell(bestId, bestCx, bestCz);
}
public readonly record struct NearestPair(Cell First, Cell Second, float FirstDist, float SecondDist);
// The two nearest cells to (x,z) with their (Euclidean) distances. Used to
// ease terrain height across the border between adjacent biome cells. Same
// 3x3 jittered-grid search as Nearest — the two closest centres always fall
// within that neighbourhood for jitter in [0,1).
public NearestPair NearestTwo(float x, float z)
{
int gx = (int)MathF.Floor(x / this._cellSize);
int gz = (int)MathF.Floor(z / this._cellSize);
float best = float.MaxValue, second = float.MaxValue;
Cell bestCell = default, secondCell = default;
for (int oz = -1; oz <= 1; oz++)
for (int ox = -1; ox <= 1; ox++)
{
int cgx = gx + ox;
int cgz = gz + oz;
float jitterX = Jitter(cgx, cgz, this._seed);
float jitterZ = Jitter(cgx, cgz, this._seed + 9871);
float cx = (cgx + jitterX) * this._cellSize;
float cz = (cgz + jitterZ) * this._cellSize;
float dx = cx - x, dz = cz - z;
float dist = dx * dx + dz * dz;
Cell cell = new((int)Hash(cgx, cgz, this._seed), cx, cz);
if (dist < best)
{
second = best; secondCell = bestCell;
best = dist; bestCell = cell;
}
else if (dist < second)
{
second = dist; secondCell = cell;
}
}
return new NearestPair(bestCell, secondCell,
MathF.Sqrt(best), MathF.Sqrt(second));
}
private static float Jitter(int x, int z, int seed)
=> (Hash(x, z, seed) & 0xFFFFFF) / (float)0x1000000; // [0,1)
private static uint Hash(int x, int z, int seed)
{
unchecked
{
uint h = (uint)(x * 374761393 + z * 668265263 + seed * 362437);
h = (h ^ (h >> 13)) * 1274126177u;
return h ^ (h >> 16);
}
}
}