three.js/examples/js/PRNG.js

// Park-Miller-Carta Pseudo-Random Number Generator
// https://github.com/pnitsch/BitmapData.js/blob/master/js/BitmapData.js

var PRNG = function () {

	this.seed = 1;
	this.next = function() { return (this.gen() / 2147483647); };
	this.nextRange = function(min, max)	{ return min + ((max - min) * this.next()) };
	this.gen = function() { return this.seed = (this.seed * 16807) % 2147483647; };

};