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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 19:18:28 -0700
Message-ID: <4FB1BCF4.7020003@jumis.com>
To: Boris Zbarsky <bzbarsky@MIT.EDU>
CC: "Gregg Tavares (勤)" <gman@google.com>, public-webapps@w3.org
On 5/14/2012 7:09 PM, Boris Zbarsky wrote:
> On 5/14/12 10:00 PM, Charles Pritchard wrote:
>> What would web fonts do in this situation, in Mozilla?
>
> Probably cry.  ;)
>
>> If I've confirmed that a font is loaded in the main thread, would it 
>> be available to a
>> worker for use in rendering?
>
> Not without some pretty serious reworking.  Which might need to happen.
>
> Of course basic text layout would also not be available without some 
> serious reworking (e.g. making the textrun cache threadsafe or 
> creating per-thread textrun caches or something), so the question of 
> web fonts is somewhat academic at the moment.
>

I meant solely for Canvas 2d.

I can live with staying away from fillText/strokeText on a worker thread 
if I'm loading fonts.
It's been broken on the main thread anyway, requiring intermediate 
Canvas surfaces for some operations.

...

SVG image and drawImage is mixed anyway; we can't transfer the data 
between threads as drawImage SVG will usually flag the Canvas as dirty 
in implementations.

We could just use Canvas 2d to handle pattern uploads for WebGL. Seems 
like that'd work without requiring fancy footwork to gain Picture/Image 
support in the worker.
SVG images would get fixed some other day.


-Charles
Received on Tuesday, 15 May 2012 02:18:52 GMT

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