JS1k: The JavaScript code golfing competition

var WIDTH=640,HEIGHT=400,context,zzdir=-1,canvas=document.getElementById("c");canvas.width=WIDTH;canvas.height=HEIGHT;context=canvas.getContext("2d");function draw(a,b,c,d,e){context.strokeStyle="rgb("+b+","+c+","+d+")";context.beginPath();y=(HEIGHT/2-e)*Math.sin(Math.PI*2*(a/WIDTH))+HEIGHT/2;context.moveTo(0,y);for(var f=0;f<WIDTH;f+=10){y=(HEIGHT/2-e)*Math.sin(Math.PI*2*((f+a)/WIDTH))+HEIGHT/2;context.lineTo(f,y);context.moveTo(f,y)}context.stroke();context.closePath();a--;e+=zzdir;if(a<=0)a=WIDTH;if(e<=0)zzdir=1;if(e>=HEIGHT)zzdir=-1;b+=Math.round(Math.sin(a)*20)-10;c+=Math.round(Math.cos(a)*20)-10;d+=Math.round(Math.tan(a)*20)-10;if(b>255||b<0)b=Math.round(Math.random()*255);if(c<0||c>255)c=Math.round(Math.random()*255);if(d<0||d>255)d=Math.round(Math.random()*255);call="draw("+a+","+b+","+c+","+d+","+e+")";setTimeout(call,0)}draw(WIDTH,Math.round(Math.random()*255),Math.round(Math.random()*255),Math.round(Math.random()*255),HEIGHT);

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

var WIDTH = 640;
var HEIGHT = 400;
var context;
var zzdir = -1;
	
var canvas = document.getElementById("c");
canvas.width = WIDTH;
canvas.height = HEIGHT;
context = canvas.getContext("2d");

function draw(z, red, green, blue, zz) {
	context.strokeStyle = "rgb(" + red + "," + green + "," + blue + ")";

	context.beginPath();
	y = ((HEIGHT/2-zz) * Math.sin((Math.PI*2)*(z/WIDTH))) + HEIGHT/2;
	context.moveTo(0, y);
	for(var x = 0; x < WIDTH; x+=10) {
		y = (HEIGHT/2-zz) * Math.sin((Math.PI*2)*((x+z)/WIDTH)) + HEIGHT/2;
		context.lineTo(x,y);
		context.moveTo(x,y);
	}
	context.stroke();
	context.closePath();
	
	z--;
	zz += zzdir;
	if(z <= 0) {
		z = WIDTH;
	}
	if(zz <= 0) {
		zzdir = 1;
	}
	if(zz >= HEIGHT) {
		zzdir = -1;
	}
	red+=Math.round(Math.sin(z)*20)-10;
	green+=Math.round(Math.cos(z)*20)-10;
	blue+=Math.round(Math.tan(z)*20)-10;
	if(red > 255 || red < 0) {
		red = Math.round(Math.random()*255);
	}
	if(green < 0 || green > 255) {
		green = Math.round(Math.random()*255);
	}
	if(blue < 0 || blue > 255) {
		blue = Math.round(Math.random()*255);
	}
	call = "draw(" + z + "," + red + "," + green + "," + blue + "," + zz + ")";
	setTimeout(call, 0);
}

draw(WIDTH, Math.round(Math.random()*255), Math.round(Math.random()*255), Math.round(Math.random()*255), HEIGHT);