Azmyth.Procedural.SimplexValueNoise.SimplexValueNoise C# (CSharp) Method

        public SimplexValueNoise(double persistence, double frequency, double amplitude, int octaves, long seed)
            : base(persistence, frequency, amplitude, octaves, seed)
        {
            perm = new short[256];
            short[] source = new short[256];
            for (short i = 0; i < 256; i++)
                source[i] = i;
            seed = seed * 6364136223846793005 + 1442695040888963407;
            seed = seed * 6364136223846793005 + 1442695040888963407;
            seed = seed * 6364136223846793005 + 1442695040888963407;
            for (int i = 255; i >= 0; i--)
            {
                seed = seed * 6364136223846793005 + 1442695040888963407;
                int r = (int)((seed + 31) % (i + 1));
                if (r < 0)
                    r += (i + 1);
                perm[i] = source[r];
                source[r] = source[i];
            }
        }