public static double[] getFastNoise1D(
Noise noise, int xSize, int samplingRate, int x, int y, int z) {
if (samplingRate == 0) {
throw new IllegalArgumentException("samplingRate cannot be 0");
}
if (xSize % samplingRate != 0) {
throw new IllegalArgumentException("xSize % samplingRate must return 0");
}
double[] noiseArray = new double[xSize + 1];
for (int xx = 0; xx <= xSize; xx += samplingRate) {
noiseArray[xx] = noise.noise3D(xx + x, y, z);
}
for (int xx = 0; xx < xSize; ++xx) {
if (xx % samplingRate != 0) {
int nx = xx / samplingRate * samplingRate;
noiseArray[nx] =
Noise.linearLerp(
xx, nx, nx + samplingRate, noiseArray[nx], noiseArray[nx + samplingRate]);
}
}
return noiseArray;
}
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;
}
public static double[][][] getFastNoise3D(
Noise noise,
int xSize,
int ySize,
int zSize,
int xSamplingRate,
int ySamplingRate,
int zSamplingRate,
int x,
int y,
int z) {
if (xSamplingRate == 0) {
throw new IllegalArgumentException("xSamplingRate cannot be 0");
}
if (zSamplingRate == 0) {
throw new IllegalArgumentException("zSamplingRate cannot be 0");
}
if (ySamplingRate == 0) {
throw new IllegalArgumentException("ySamplingRate cannot be 0");
}
if (xSize % xSamplingRate != 0) {
throw new IllegalArgumentException("xSize % xSamplingRate must return 0");
}
if (zSize % zSamplingRate != 0) {
throw new IllegalArgumentException("zSize % zSamplingRate must return 0");
}
if (ySize % ySamplingRate != 0) {
throw new IllegalArgumentException("ySize % ySamplingRate must return 0");
}
double[][][] noiseArray = new double[xSize + 1][zSize + 1][ySize + 1];
for (int xx = 0; xx <= xSize; xx += xSamplingRate) {
for (int zz = 0; zz <= zSize; zz += zSamplingRate) {
for (int yy = 0; yy <= ySize; yy += ySamplingRate) {
noiseArray[xx][zz][yy] = noise.noise3D(x + xx, y + yy, z + zz, true);
}
}
}
for (int xx = 0; xx < xSize; ++xx) {
for (int zz = 0; zz < zSize; ++zz) {
for (int yy = 0; yy < ySize; ++yy) {
if (xx % xSamplingRate != 0 || zz % zSamplingRate != 0 || yy % ySamplingRate != 0) {
int nx = xx / xSamplingRate * xSamplingRate;
int ny = yy / ySamplingRate * ySamplingRate;
int nz = zz / zSamplingRate * zSamplingRate;
int nnx = nx + xSamplingRate;
int nny = ny + ySamplingRate;
int nnz = nz + zSamplingRate;
double dx1 = ((double) (nnx - xx) / (double) (nnx - nx));
double dx2 = ((double) (xx - nx) / (double) (nnx - nx));
double dy1 = ((double) (nny - yy) / (double) (nny - ny));
double dy2 = ((double) (yy - ny) / (double) (nny - ny));
noiseArray[xx][zz][yy] =
((double) (nnz - zz) / (double) (nnz - nz))
* (dy1 * (dx1 * noiseArray[nx][nz][ny] + dx2 * noiseArray[nnx][nz][ny])
+ dy2
* (dx1 * noiseArray[nx][nz][nny] + dx2 * noiseArray[nnx][nz][nny]))
+ ((double) (zz - nz) / (double) (nnz - nz))
* (dy1 * (dx1 * noiseArray[nx][nnz][ny] + dx2 * noiseArray[nnx][nnz][ny])
+ dy2
* (dx1 * noiseArray[nx][nnz][nny]
+ dx2 * noiseArray[nnx][nnz][nny]));
}
}
}
}
return noiseArray;
}