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Re: [whatwg] Counterproposal for canvas in workers

From: Robert O'Callahan <robert@ocallahan.org>
Date: Sun, 20 Oct 2013 09:22:55 +0200
Message-ID: <CAOp6jLb2=WGjtLxE6azc2L4Rg9BRSjcQ2yTM+2ByytcD1XkRcg@mail.gmail.com>
To: Glenn Maynard <glenn@zewt.org>
Cc: "whatwg@whatwg.org" <whatwg@whatwg.org>, Rik Cabanier <cabanier@gmail.com>
On Fri, Oct 18, 2013 at 4:17 PM, Glenn Maynard <glenn@zewt.org> wrote:

> On Thu, Oct 17, 2013 at 10:25 PM, Robert O'Callahan <robert@ocallahan.org
> >wrote:
> > On Fri, Oct 18, 2013 at 3:10 PM, Glenn Maynard <glenn@zewt.org> wrote:
> >>  Also, with the "transferToImageBuffer" approach, if you want to render
> >> from a worker into multiple canvases in the UI thread, you have to post
> >> those ImageBuffers over to the main thread each frame, which has the
> same
> >> (potential) synchronization issues as the transferDrawingBufferToCanvas
> >> proposal.
> >
> > What are those issues? You can do a single postMessage passing a complete
> > set of ImageBItmaps.
> >
>
> See
> http://lists.w3.org/Archives/Public/public-whatwg-archive/2013Oct/0193.html
> .
> I don't know the answer to this; my feeling is that posting to the UI
> thread and scripts in the UI thread may or may not have
> (performance/smoothness) issues, but doing it all in the worker avoids any
> potential for this issue.
>

I'm confused here. You said "if you want to render from a worker into
multiple canvases in the UI thread", which I took to mean that you wanted
to synchronize canvas updates from workers with DOM changes made by the UI
thread. But now you're saying you don't want to do that. So I don't know
what you meant.

Rob
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Received on Sunday, 20 October 2013 07:23:20 UTC

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