/**
 * A soft-hardware RNG for as3 based on the discrepancy
 * between process time and the system clock.
 *
 * @author hdachev http://blog.controul.com
 */

package com.controul.math.rng
{
	import flash.utils.getTimer;

	public class ClockDrift
	{

		public static const instance : ClockDrift = new ClockDrift ();

		public static function random ( bits : uint = 32 ) : uint
		{
			return instance.random ( bits );
		}

		public function random ( bits : uint = 32 ) : uint
		{
			if ( bits > 32 )
				throw new Error ( this + " @ ClockDrift::random () :    Cannot return more than 32 bits: return type is uint." );

			var r : uint = 0,
				i : uint = 0,
				t : uint = getTimer (),
				n : Number;

			for ( ;; )
			{
				if ( t != ( t = getTimer () ) )
				{
					if ( i & 1 )
						r |= 1;
					bits --;
					if ( bits )
					{
						i = 0;
						r <<= 1;
					}
					else
						break;
				}
				i ++;
			}

			return r;
		}

	}

}