W3C home > Mailing lists > Public > whatwg@whatwg.org > March 2010

[whatwg] Offscreen canvas (or canvas for web workers).

From: Maciej Stachowiak <mjs@apple.com>
Date: Fri, 12 Mar 2010 17:25:11 -0800
Message-ID: <71A64C40-E5BE-4FB6-B962-DF90CABBD034@apple.com>

On Mar 12, 2010, at 2:35 PM, Jonas Sicking wrote:

> On Fri, Mar 12, 2010 at 12:46 PM, Oliver Hunt <oliver at apple.com>  
> wrote:
>>
>> On Mar 12, 2010, at 12:16 PM, Jonas Sicking wrote:
>>> I'm not saying that the proposed API is bad. It just doesn't seem to
>>> solve the (seemingly most commonly requested) use case of
>>> rotating/scaling images. So if we want to solve those use cases we
>>> need to either come up with a separate API for that, or extend this
>>> proposal to solve that use case somehow.
>>
>> Just for reference I think one thing that people are forgetting  
>> that there is a difference between
>> being computationally faster, and being more responsive.
>
> As I mentioned in my email, if you look at the steps listed, enough of
> them happen *on the main thread* that you're spending far more of the
> main threads CPU cycles than you'd like. Possibly even more than doing
> all the resizing on the main thread.
>
> With the other improvements suggested by David things do definitely
> look different, but those are not in a proposal yet.

In general a copy is a fair bit faster than an image rotate or resize,  
though I don't know if it is faster enough for reasonable image sizes  
to matter.

Regards,
Maciej
Received on Friday, 12 March 2010 17:25:11 UTC

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