/*(c) 2006 - 2008 AllenPort Co. All Rights Reserved.
All versions of this code, including the source and executable versions, 
constitute the intellectual property of AllenPort Co., which expressly reserves 
any and all U.S. and foreign rights and benefits to the code under copyright, 
trade secret and any other intellectual property law or international treaty 
whatsoever. Use of the code is subject to the terms and conditions of a separate 
written license agreement, and the code shall not be reproduced, modified, distributed 
or otherwise used in any form or manner whatsoever without obtaining the prior written 
permission of AllenPort Co. Any unauthorized reproduction or distribution of the code, 
or any portion of it, may result in civil and criminal penalties and be prosecuted 
to the fullest extent of the law.*/
// prng4.js - uses Arcfour as a PRNG

function Arcfour() {
  this.i = 0;
  this.j = 0;
  this.S = new Array();
}

// Initialize arcfour context from key, an array of ints, each from [0..255]
function ARC4init(key) {
  var i, j, t;
  for(i = 0; i < 256; ++i)
    this.S[i] = i;
  j = 0;
  for(i = 0; i < 256; ++i) {
    j = (j + this.S[i] + key[i % key.length]) & 255;
    t = this.S[i];
    this.S[i] = this.S[j];
    this.S[j] = t;
  }
  this.i = 0;
  this.j = 0;
}

function ARC4next() {
  var t;
  this.i = (this.i + 1) & 255;
  this.j = (this.j + this.S[this.i]) & 255;
  t = this.S[this.i];
  this.S[this.i] = this.S[this.j];
  this.S[this.j] = t;
  return this.S[(t + this.S[this.i]) & 255];
}

Arcfour.prototype.init = ARC4init;
Arcfour.prototype.next = ARC4next;

// Plug in your RNG constructor here
function prng_newstate() {
  return new Arcfour();
}

// Pool size must be a multiple of 4 and greater than 32.
// An array of bytes the size of the pool will be passed to init()
var rng_psize = 256;
