generate-numbers.js

/**
 * @author KurozeroPB
 */
class Numbers {
    /**
     * Create a new instance
     * @param {Number|Number[]} seed
     */
    constructor(seed) {
        if (seed == undefined) {
            seed = new Date().getTime();
        }

        this.N = 624;
        this.M = 397;
        this.MATRIX_A = 0x9908b0df;
        this.UPPER_MASK = 0x80000000;
        this.LOWER_MASK = 0x7fffffff;

        this.mt = new Array(this.N);
        this.mti = this.N + 1;

        if (seed instanceof Array) {
            this.init_by_array(seed, seed.length);
        } else {
            this.init_seed(seed);
        }
    }

    /**
     * Initialize with number
     * @param {Number} sd
     */
    init_seed(sd) {
        this.mt[0] = sd >>> 0;
        for (this.mti = 1; this.mti < this.N; this.mti++) {
            var s = this.mt[this.mti - 1] ^ (this.mt[this.mti - 1] >>> 30);
            this.mt[this.mti] = (((((s & 0xffff0000) >>> 16) * 1812433253) << 16) + (s & 0x0000ffff) * 1812433253) + this.mti;
            this.mt[this.mti] >>>= 0;
        }
    }

    /**
     * Initialize with number array
     * @param {Number[]} init_key
     * @param {Number} key_length
     */
    init_by_array(init_key, key_length) {
        var i, j, k;
        this.init_seed(19650218);
        i = 1;
        j = 0;
        k = (this.N > key_length ? this.N : key_length);
        for (; k; k--) {
            var s1 = this.mt[i - 1] ^ (this.mt[i - 1] >>> 30);
            this.mt[i] = (this.mt[i] ^ (((((s1 & 0xffff0000) >>> 16) * 1664525) << 16) + ((s1 & 0x0000ffff) * 1664525))) + init_key[j] + j;
            this.mt[i] >>>= 0;
            i++;
            j++;
            if (i >= this.N) {
                this.mt[0] = this.mt[this.N - 1];
                i = 1;
            }
            if (j >= key_length) j = 0;
        }
        for (k = this.N - 1; k; k--) {
            var s2 = this.mt[i - 1] ^ (this.mt[i - 1] >>> 30);
            this.mt[i] = (this.mt[i] ^ (((((s2 & 0xffff0000) >>> 16) * 1566083941) << 16) + (s2 & 0x0000ffff) * 1566083941)) - i;
            this.mt[i] >>>= 0;
            i++;
            if (i >= this.N) {
                this.mt[0] = this.mt[this.N - 1];
                i = 1;
            }
        }

        this.mt[0] = 0x80000000;
    }

    /**
     * Generates a random number on [0,0xffffffff] interval
     * @returns {Number}
     */
    random_int() {
        var y;
        var mag01 = [0x0, this.MATRIX_A];

        if (this.mti >= this.N) {
            var kk;

            if (this.mti == this.N + 1) this.init_seed(5489);

            for (kk = 0; kk < this.N - this.M; kk++) {
                y = (this.mt[kk] & this.UPPER_MASK) | (this.mt[kk + 1] & this.LOWER_MASK);
                this.mt[kk] = this.mt[kk + this.M] ^ (y >>> 1) ^ mag01[y & 0x1];
            }
            for (; kk < this.N - 1; kk++) {
                y = (this.mt[kk] & this.UPPER_MASK) | (this.mt[kk + 1] & this.LOWER_MASK);
                this.mt[kk] = this.mt[kk + (this.M - this.N)] ^ (y >>> 1) ^ mag01[y & 0x1];
            }
            y = (this.mt[this.N - 1] & this.UPPER_MASK) | (this.mt[0] & this.LOWER_MASK);
            this.mt[this.N - 1] = this.mt[this.M - 1] ^ (y >>> 1) ^ mag01[y & 0x1];

            this.mti = 0;
        }

        y = this.mt[this.mti++];

        y ^= (y >>> 11);
        y ^= (y << 7) & 0x9d2c5680;
        y ^= (y << 15) & 0xefc60000;
        y ^= (y >>> 18);

        return y >>> 0;
    }

    /**
     * Generates a random number on [0,0x7fffffff] interval
     * @returns {Number}
     */
    random_int31() {
        return (this.random_int() >>> 1);
    }

    /**
     * Generates a random number on [0,1] real-interval
     * @returns {Number}
     */
    random_incl() {
        return this.random_int() * (1.0 / 4294967295.0);
    }

    /**
     * Generates a random number on [0,1] real-interval
     * @returns {Number}
     */
    random() {
        return this.random_int() * (1.0 / 4294967296.0);
    }

    /**
     * Generates a random number on [0,1] real-interval
     * @returns {Number}
     */
    random_excl() {
        return (this.random_int() + 0.5) * (1.0 / 4294967296.0);
    }

    /**
     * Generates a random number on [0,1] with 53-bit resolution
     * @returns {Number}
     */
    random_long() {
        var a = this.random_int() >>> 5, b = this.random_int() >>> 6;
        return (a * 67108864.0 + b) * (1.0 / 9007199254740992.0);
    }
}