title: How to make a rotating gradient (on a circle)?
body: <p>I create a simple circle with the arc function:</p>
  
  <pre><code>/* ctx is the 2d context */ 
  ctx.beginPath();
    var gradient = ctx.createLinearGradient(0, 0, this.radius, this.radius);
    gradient.addColorStop(0, '#FF0000');
    gradient.addColorStop(1, '#FFFFFF');
    ctx.lineWidth = 10;
  
    ctx.arc(this.radius, this.radius, this.radius, 0, 2*Math.PI, true);
    ctx.strokeStyle = gradient;
  ctx.stroke();
  </code></pre>
  
  <p>So I want to rotate the gradient, is that possible?
  I've tried with <em>ctx.rotate(x)</em> but that rotates the whole circle!</p>