Tiny Java utilities for generating high-quality random int values from a large state array

RandomUtils.java

public class RandomUtils
{
    /**
     * Generates a state array for use with {@link #randomInt(int[])}; this state array will be random using {@code Math.random()}.
     * @return a 129-element int array with contents randomized by {@code Math.random()}
     */
    public static int[] initialState()
    {
        final int[] state = new int[129];
        for(int i = 0; i < 129; i++)
        {
            state[i] = (int)((Math.random() * 2.0 - 1.0) * 0x80000000);
        }
        return state;
    }
    /**
     * Generates a state array for use with {@link #randomInt(int[])}; this state array will be determined by the given {@code seed}.
     * @param seed can be any int; will determine the contents of the returned state, but only 2 to the 32 states will be possible
     * @return a 129-element int array with contents determined by seed
     */
    public static int[] initialState(int seed)
    {
        final int[] state = new int[129];
        for(int i = 0, z; i < 129; i++)
        {
            z = (seed += 0x9E3779B9);
            z = (z ^ (z >>> 16)) * 0x85EBCA6B;
            z = (z ^ (z >>> 13)) * 0xC2B2AE35;
            state[i] = z ^ (z >>> 16);
        }
        return state;
    }
    /**
     * Gets a random number given a large array of state. This should be called with an int array for state that has a
     * length of at least 129, and the array will be altered by this call. There are no restrictions on what the
     * contents of state can be; it can be all 0 on the first call. For the quality to stay intact, it is recommended
     * that {@code state[128]} not be changed except by this method; that element is normally the last one in the
     * recommended size of array, and it is used to store special state that should change in a specific pattern.
     * When used as intended, this should pass stringent tests for random number quality.
     * @param state int array that must have a length of at least 129; contents will be changed
     * @return a pseudo-random int using the given state and choice 
     */
    public static int randomInt(int[] state)
    {
        final int c = (state[128] += 0xB9A2842F);
        return (state[c * 0x85157AF5 >>> 25] += (c >>> (c >>> 28)) * 0x632BE5AB);
    }
}