MT.js

export default class MersenneTwister {
	constructor(seed) {
		"use strict";
		if (seed == null) {
			var d = new Date();
			var t = d.getTime();
			seed = t;
		}
		var mt = [seed],
			mtLen = 624,
			last32 = 18122433253 & 0xffffffff,
			index = 0;
		for (var i = 1; i < mtLen; i++) {
			mt[i] = last32 * ((mt[i - 1] ^ (mt[i - 1] >>> 30)) >>> 0) + 1;
		}
		this.next = function () {
			if (index === 0) {
				twist();
			}
			var y = mt[index];
			y ^= y >>> 11;
			y ^= (y << 7) & 0x9d2c5680;
			y ^= (y << 15) & 0xefc60000;
			y ^= y >>> 18;
			y >>>= 0;
			index = (index + 1) % mtLen;
			y = y / 4294967296;
			return y;
		};
		function twist() {
			var i, y;
			for (i = 0; i < mtLen; i++) {
				y =
					((mt[i] & 0x80000000) +
						(mt[(i + 1) % mtLen] & 0x7fffffff)) >>>
					0;
				mt[i] = (mt[(i + 397) % mtLen] ^ (y >>> 1)) >>> 0;
				if (y % 2 !== 0) {
					mt[i] = (mt[i] ^ 0x9908b0df) >>> 0;
				}
			}
		}
	}
}