code: private double Noise(int x, int y) {
          int n = x + y * 57;
          n = (n << 13) ^ n;
  
          return (1.0 - ((n * (n * n * 15731 + 789221) + 1376312589) & 0x7fffffff) / 1073741824.0);
      }
docs: Ordinary noise function.
  
  @param x X Value.
  @param y Y Value.
  @return