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

Jonas Sicking jonas at sicking.cc
Fri Mar 12 16:19:55 PST 2010

On Fri, Mar 12, 2010 at 3:38 PM, David Levin <levin at google.com> wrote:
> On Fri, Mar 12, 2010 at 2:35 PM, Jonas Sicking <jonas at sicking.cc> 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.
> There is the other scenario I mentioned, but I'll see what I can do about
> separately working up a proposal for adding those methods because they were
> next on my list to deal with. (fromBlob/load may be enough for this.)

Note that the other proposals that have been made has put toBlob on
HTMLCanvasElement, not on the context. That makes the most sense for
the main-thread canvas as that way its available on all contexts.

/ Jonas

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