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Re: exposing CANVAS or something like it to Web Workers

From: Charles Pritchard <chuck@jumis.com>
Date: Mon, 14 May 2012 13:32:12 -0700
Message-ID: <4FB16BCC.3070704@jumis.com>
To: "Gregg Tavares (勤)" <gman@google.com>
CC: Web Applications Working Group WG <public-webapps@w3.org>
On 5/14/2012 1:01 PM, Gregg Tavares (勤) wrote:
> I'd like to work on exposing something like CANVAS to web workers.
>
> Ideally how over it works I'd like to be able to
>
> *) get a 2d context in a web worker
> *) get a WebGL context in a web worker
> *) download images in a web worker and the images with both 2d 
> contexts and WebGL contexts
>
> Any thoughts?

As far as implementation, I'd love to be able to pass webkit's 
document.getCSSCanvasContext('2d') around.
It seems like a safe place to experiment.

I can get a lot done with CanvasPattern as a transferable, without 
needing to add Image (or video) into the worker context.

Notes:
1. getCSSCanvasContext is non-standard. It works with CSS image 
-webkit-canvas.
2. I heard that a more generic "-moz-element()" paint server is supposed 
to replace -webkit-canvas in time.
3. Passing the CSS canvas context would let me render off-frame and 
update a canvas visible on the document automatically.

Canvas -should- have toBlob and a typed array buffer for ImageData.
They are both useful for passing image data back to the main frame.


 From my experience with WebGL, I think it should be considered with 
added care and lower priority.
There are stability, speed and memory issues. WebGL in workers seems to 
augment 2d, are there other big benefits?


-Charles
Received on Monday, 14 May 2012 20:32:38 GMT

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