// 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;