internal static Double interpolate_X_4( Double x, Double y, Double z, Double w, Double xs, Int32 x0, Int32 x1, Int32 iy, Int32 iz, Int32 iw, Int32 seed, WorkerNoise4 noisefunc) { var v1 = noisefunc(x, y, z, w, x0, iy, iz, iw, seed); var v2 = noisefunc(x, y, z, w, x1, iy, iz, iw, seed); return Lerp(xs, v1, v2); }