examples/09_relative_values.html

<!DOCTYPE html>
<html lang="en">
	<head>
		<title>Tween.js / relative values</title>
		<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
		<link href="css/style.css" media="screen" rel="stylesheet" type="text/css" />
		<style type="text/css">
			.box {
				width: 100px;
				height: 100px;
				margin: 10px;
				padding: 10px;
				display: inline-block;
				float: left;
			}
			#target1 {
				background: #fcc;
			}
		</style>
		<script src="../src/Tween.js"></script>
		<script src="js/RequestAnimationFrame.js"></script>
		<script>
			window.onload = function() {
				init();
				animate();
			}

			function init() {
				var target1 = document.getElementById( 'target1' ),
					tween1 = new TWEEN.Tween( target1.dataset )
						.to( { top: "+20", left: "-20" }, 1000 )
						.repeat( 5 )
						.delay( 500 )
						.easing( TWEEN.Easing.Exponential.In )
						.onUpdate( function() {
							updateBox( target1, this );
						})
						.start();
					
					updateBox( target1, target1.dataset );
			}

			function animate( time ) {

				requestAnimationFrame( animate );

				TWEEN.update( time );

			}

			function updateBox( box, params ) {
				var field,
					s = box.style;
				for (field in params) {
					s[field] = params[field] + "px";
				}
			}

		</script>
	</head>
	<body>
		<div id="info">
			<h1><a href="http://github.com/tweenjs/tween.js">tween.js</a></h1>
			<h2>09 _ relative values</h2>
			<p>Tweening to relative values, with repeat.</p>
		</div>
		<div style="position: absolute; left: 400px; ">
			<div id="target1" style="position: absolute;" data-top="150" class="box">
			</div>
		</div>
	</body>
</html>