title: HTML5: Canvas performs too slow on lower end computers
body: <p>My problem is that my javascript/canvas performs very slowly on lower end computers (Even though they can run even more challenging <a href="http://9elements.com/io/projects/html5/canvas/" rel="nofollow">canvas</a> <a href="http://www.benjoffe.com/code/demos/canvascape/" rel="nofollow">scripts</a> smoothly).
  I'm trying to do a simple animation depending on user selection.</p>
  
  <p>When drawing on the canvas directly proved to be too slow, I draw on a hidden canvas and saved all frames (<code>getImageData</code>) to <code>data</code> and then called <code>animate(1);</code> to draw on my real canvas.</p>
  
  <pre><code>function animate(i){
      if(i &lt; 12){
          ctx2.putImageData(data[i], 0, 0);
          setTimeout(function(){animate(i+1)},1);
      }
  }
  </code></pre>
  
  <p>But even this is too slow. What do I do?</p>