/*
* ByteWarrior library for playing and exporting bytebeat tunes in your browser
* by Multiversum
* Usage: new ByteWarrior(pattern_string, sampleRate, duration), then call play() and pause() methods
* Pattern string is mandatory, you can omit all other parameters, then their defaults will be:
* sample rate - 8000 Hz, duration - 16 sec
* pattern_string accepts a JS expression from single 't' parameter
* The following functions can be specified without Math: sin, cos, tan, floor, ceil
* Example:
* var bb = new ByteWarrior("((t<<1)^((t<<18)+(t>>7)&t>>12))|t>>(4-(1^7&(t>>19)))|t>>7"); bb.play()
* Export to WAV is done with accessing wavedata parameter:
* var bb = new ByteWarrior(pattern,8000,120);
* var wavDataURI = bb.wavedata;
* This library is public domain. Have fun!
*/

ByteWarrior = function(pstring, sampleRate, duration) {
	this.rate = sampleRate||8000;
	this.duration = duration||16;
	this.pattern = eval("(function(t){return "+pstring.replace(/sin|cos|tan|floor|ceil/g,function(s){return "Math."+s})+"})");
	this.audio = new Audio();
	this.toWav = function(){
		var nsamples = this.duration*this.rate,
			i2b=function(v){return [0xFF&v,0xFF&(v>>8),0xFF&(v>>16),0xFF&(v>>24)]},
			wave=[].concat([82,73,70,70],i2b(44+nsamples),
			[87,65,86,69,102,109,116,32,16,0,0,0,1,0,1,0],i2b(this.rate),i2b(this.rate),
			[1,0,8,0,100,97,116,97],i2b(nsamples));
		for(var t=0;t<nsamples;t++)wave.push(0xFF&this.pattern(t));
		return "data:audio/x-wav;base64,"+btoa(wave.reduce(function(a,b){return a+String.fromCharCode(b)},''))
	};
	this.audio.src = this.wavedata = this.toWav();
	this.play = function(){this.audio.play()};
	this.pause = function(){this.audio.pause()}
}