Re: [whatwg] Canvas image to blob/dataurl within Worker

(sorry for double email) Just one question about how requestAnimationFrame
is expected to work. Could we get rAF added to workers? Would it be able to
simply fire whenever it does on the main thread, as if it postMessage'd to
the worker every time it was called but without the extra postMessage
latency? To do that I guess workers need to be associated with a window.
For normal workers this seems fine but if OffscreenCanvas is expected to
work in shared or service workers this is a little tricker to define.
Perhaps requestAnimationFrame could be a method on OffscreenCanvas and it
fires based on the window the HTMLCanvasElement it came from is currently
in? Then you have a convenient way to synchronise rendering with the window
it will ultimately be displayed in, without having to know in advance which
window that is.

Ashley



On 8 April 2015 at 16:36, Ashley Gullen <ashley@scirra.com> wrote:

> This looks like it will cover running a HTML5 game engine from a worker
> very nicely and with little performance overhead. Good stuff!
>
> Ashley
>
>
> On 8 April 2015 at 00:41, Kenneth Russell <kbr@google.com> wrote:
>
>> On Wed, Mar 25, 2015 at 6:41 PM, Kenneth Russell <kbr@google.com> wrote:
>> > On Wed, Mar 25, 2015 at 1:22 PM, Robert O'Callahan <
>> robert@ocallahan.org> wrote:
>> >> On Wed, Mar 25, 2015 at 11:41 PM, Anne van Kesteren <annevk@annevk.nl>
>> >> wrote:
>> >>>
>> >>> On Fri, Mar 20, 2015 at 11:15 PM, Robert O'Callahan
>> >>> <robert@ocallahan.org> wrote:
>> >>> > My understanding is that the current consensus proposal for canvas
>> in
>> >>> > Workers is not what's in the spec, but this:
>> >>> > https://wiki.whatwg.org/wiki/WorkerCanvas
>> >>> > See "Canvas in Workers" threads from October 2013 for the
>> discussion.
>> >>> > svn
>> >>> > is failing me but the CanvasProxy proposal in the spec definitely
>> >>> > predates
>> >>> > those threads.
>> >>> >
>> >>> > Ian, unless I'm wrong, it would be helpful to remove the CanvasProxy
>> >>> > stuff
>> >>> > from the spec to avoid confusion.
>> >>> >
>> >>> > That proposal contains WorkerCanvas.toBlob, which needs to be
>> updated to
>> >>> > use promises.
>> >>>
>> >>> There's also https://wiki.whatwg.org/wiki/WorkerCanvas2 it seems. It
>> >>> would be interesting to know what the latest on this is.
>> >>
>> >>
>> >> Right now that appears to be just a copy of WorkerCanvas with some
>> >> boilerplate text added. I assume someone's working on it and will
>> mention it
>> >> on this list if/when they're ready to discuss it :-).
>> >
>> > Yes, apologies for letting it sit there in an incomplete state.
>> > Recently feedback from more browser implementers was gathered about
>> > the WorkerCanvas proposal. I will assemble it into WorkerCanvas2 and
>> > follow up on this thread in a day or two.
>>
>> I apologize for taking so long to update this proposal, but it's now
>> in a reasonable state:
>> https://wiki.whatwg.org/wiki/OffscreenCanvas
>>
>> (Renamed per feedback from Anne -- thanks.)
>>
>> Please offer your feedback. Multiple browser implementers agreed on
>> this form of the API at a recent face-to-face meeting of the WebGL
>> working group, and the proposal should be able to address multiple use
>> cases. I'm very interested in prototyping it to see if it can offer
>> better parallelism.
>>
>> -Ken
>>
>>
>>
>> > -Ken
>> >
>> >
>> >> Rob
>> >> --
>> >> oIo otoeololo oyooouo otohoaoto oaonoyooonoeo owohooo oioso oaonogoroyo
>> >> owoiotoho oao oboroootohoeoro oooro osoiosotoeoro owoiololo oboeo
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>> >> owohooo
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>> o‘oRoaocoao,o’o
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>>
>
>

Received on Wednesday, 8 April 2015 15:47:00 UTC