On May 20, 2010, at 6:24 PM, Robert O'Callahan wrote:

> On Fri, May 21, 2010 at 12:50 PM, Maciej Stachowiak <[email protected]> wrote:
> I'd also love to hear from Mike Shaver and others from the original thread 
> what they think of this API proposal.
>  
> I think Shaver's feedback still applies: on any device with a GPU, we can 
> optimize canvas and/or rendering enough that scaling images is no problem on 
> the main thread. So this API would have a short useful lifetime ... possibly 
> negative.
> 
> Coming thread full circle, I now think there are good use cases for 
> off-main-thread canvas, in particular with WebGL, but I guess that deserves 
> its own thread again :-).

As far as I can tell, the proposed API doesn't enable resizing off the main 
thread. It is an API on HTMLImageElement so you can't call it from a worker. 
And it returns synchronously so the main thread has to block until the resize 
is done regardless. It returns a Blob, so I suppose it may be possible that the 
intent is to make a magical blob that's actually backed by a background thread 
asynchronous computation instead of data. That wasn't clear to me from the 
proposal. It would be a little weird.

Regards,
Maciej

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