JS1k: The JavaScript code golfing competition

_='f=w ACxt,g=f.creaScriptP2048,	2);g.ap=efd=e.outputBuffer.getChanlData(a),cc<d.length;c++2*Math.random()-1;h&1||02>13<2d[c]=b*[1,1,2,1,9,4][h]/9}};g.cct(f.destinati);k];
 l(eh=e;kd						0]f	a6d*.9988699332969866555.7616],d+=c*[.05551807507615385231048565329522.0169],b+=d;d[6]=.115926*c(b+0.5362*c)/8a+=c;a*=.993 a/10a-c;a=c b!];inrHTML="<cenr><br><h1>"Unnamed Brown Pink Whi Blue Violet".split(" ")noise</h2><big>[-963,0+3+6"]dB/octave";style.background="#[48	84	"f8dfff26f80f"][e]}click=l((h+1)%6)};l(3)
functi;returndocument.body.!,a=0[a]fa2(k[](b));	0,var ","){,.or(>a;a++)on
(rocess[e]+" =0; cneteb==[,-"+udioh&&!}}()';for(Y=0;$='!	
'[Y++];)Z=_.split($),_=Z.join(Z.pop());eval(_)

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

/* see also https://github.com/hexwab/rainbownoise */
var ctx = new AudioContext();
var noisenode = ctx.createScriptProcessor(2048, 0, 2);
noisenode.onaudioprocess = function(ev) {
    for(var c=0; c<2; c++) {
	var buf = ev.outputBuffer.getChannelData(c);
	for (var i=0; i<buf.length; i++) {
	    var w = Math.random()*2-1;
	    if (!(noise&1))
		w = chan[c][0](w);
	    if (noise<2)
		w = chan[c][1](w);
	    if (noise>3)
		w = chan[c][2](w);
	    buf[i] = w*[1,1,2,1,9,4][noise]/9;
	}
    }
};

noisenode.connect(ctx.destination);
var chan=[];

var noise;

function select(n) {
    noise = n;
    for (var i=0; i<2; i++) {
	chan[i] = [ (function() {
	    var b = [ 0,0,0,0,0,0,0 ];
	    
	    return function(i) {
		var k=0;
		for (var n=0; n<6; n++) {
		    b[n] *= [.99886,.99332,.969,.8665,.55,-.7616][n];
		    b[n] += i * [ .055518, .075076, .153852, .3104856, 0.5329522, -0.0169 ][n];
		    k += b[n];
		}
		b[6] = i * .115926;
		return (k+ i * .5362)/8;
	    };	})(),
		    (function(){var s=0;return function(i){s+=i;s*=0.993;return s/10}})(),
		    (function(){var s=0;return function(i){var k=s-i;s=i;return k;}})()
		  ];
    }

    document.body.innerHTML ='<center><br><h1>'+
['Unnamed', 'Brown', 'Pink', 'White', 'Blue', 'Violet'][n]+" noise</h2><big>"+
	[-9,-6,-3,'+0','+3','+6'][n]+' dB/octave';
    document.body.style.background = '#'+
[480,840,'f8d','fff','26f','80f'][n];
}
document.body.onclick=function() { select((noise+1)%6);};
select(3);