The clip function

• Arguments to the function
• An example

The clip function can be used when you want to restrict any drawing to a particular area of the canvas. You draw a path without stroking or filling it, call the clip function and then any further drawing will be restricted to that area. There is (currently) no resetClip function so you need to save the state of the canvas before you clip it and then restore it when you're finished - as the example shows.

In the latest canvas specification you can also give the function a Path2D object to clip to which specifies the clipping area. This isn't implemented in most browsers yet though.

Arguments to the function

• Optionally you can specify a Path2D object to be clipped to. If not given the default path is clipped to.
  
  Clip to the default path:

  context.clip();

  Clip to the given Path2D object:

  context.clip(path);

An example

<script>
    window.onload = function ()
    {
        var canvas  = document.getElementById("cvs");
        var context = canvas.getContext('2d');
        
        context.save();
            
            context.beginPath();
            context.rect(50,50,50,50);
            context.clip();
    
            // Because the canvas is currently clipped only part of the rectangle is drawn on the canvas
            context.fillRect(0,0,600,250);
    
        context.restore();
    }
</script>