public static double[][] getFastNoise2D(
Noise noise,
int xSize,
int zSize,
int samplingRate,
int x,
int y,
int z,
int xZoom,
int zZoom) {
if (samplingRate == 0) {
throw new IllegalArgumentException("samplingRate cannot be 0");
}
if (xSize % samplingRate != 0) {
throw new IllegalArgumentException("xSize % samplingRate must return 0");
}
if (zSize % samplingRate != 0) {
throw new IllegalArgumentException("zSize % samplingRate must return 0");
}
double[][] noiseArray = new double[xSize + 1][zSize + 1];
for (int xx = 0; xx <= xSize; xx += samplingRate) {
noiseArray[xx] = new double[zSize + 1];
for (int zz = 0; zz <= zSize; zz += samplingRate) {
noiseArray[xx][zz] = noise.noise3D((x + xx) >> xZoom, y, (z + zz) >> zZoom);
}
}
for (int xx = 0; xx < xSize; ++xx) {
if (xx % samplingRate != 0) {
noiseArray[xx] = new double[zSize + 1];
}
for (int zz = 0; zz < zSize; ++zz) {
if (xx % samplingRate != 0 || zz % samplingRate != 0) {
int nx = xx / samplingRate * samplingRate;
int nz = zz / samplingRate * samplingRate;
noiseArray[xx][zz] =
Noise.bilinearLerp(
xx,
zz,
noiseArray[nx][nz],
noiseArray[nx][nz + samplingRate],
noiseArray[nx + samplingRate][nz],
noiseArray[nx + samplingRate][nz + samplingRate],
nx,
nx + samplingRate,
nz,
nz + samplingRate);
}
}
}
return noiseArray;
}
