我正在为我的动画使用画布和 webkitrequestAnimation 框架。但是，动画是即时的，而不是流畅的。它太快了，我看不到任何动画。如何使动画流畅？
<!doctype html>
<html>
<head>
<meta charset="utf-8">
<title>Wave 2</title>
</head>
<body>
<canvas id="canvas" width="400" height="400"></canvas>
<script>
window.onload = function () {
var canvas = document.getElementById('canvas'),
context = canvas.getContext('2d'),
angle = 0,
range = 50,
centerY = canvas.height / 2,
xspeed = 1,
yspeed = 0.05,
xpos = 0,
ypos = centerY;
context.lineWidth = 2;
(function drawFrame () {
window.webkitrequestAnimationFrame(drawFrame, canvas);
context.beginPath();
context.moveTo(xpos, ypos);
//Calculate the new position.
xpos += xspeed;
angle += yspeed;
ypos = centerY + Math.sin(angle) * range;
context.lineTo(xpos, ypos);
context.stroke();
}());
};
</script>
</body>
</html>