- From: Justin Novosad <junov@chromium.org>
- Date: Tue, 18 Dec 2012 11:36:17 -0500
- To: Kevin Gadd <kevin.gadd@gmail.com>
- Cc: Vladimir Vukicevic <vladimir@pobox.com>, Rik Cabanier <cabanier@gmail.com>, whatwg@lists.whatwg.org, Jeff Muizelaar <jmuizelaar@mozilla.com>, Ian Hickson <ian@hixie.ch>, robert@ocallahan.org
> > > >> Each time you wait for that callback, won't any pending drawing >> operations to your canvas get flushed, resulting in the scene slowly >> rendering onscreen? >> > > Another great reason to batch the calls, as described above. > Another solution is to use an offscreen canvas. > > >> >> -kg >> >> On Tue, Dec 18, 2012 at 7:39 AM, Justin Novosad <junov@chromium.org> >> wrote: >> > On Tue, Dec 18, 2012 at 10:17 AM, Kevin Gadd <kevin.gadd@gmail.com> >> wrote: >> >> >> >> Sorry, upon reading over the ImageBitmap part of the spec again I'm >> >> confused: Why is constructing an ImageBitmap asynchronous? I thought >> >> any decoding isn't supposed to happen until drawImage, so I don't >> >> really understand why this operation involves a callback and a delay. >> > >> > >> > The image may have to be downloaded, which is a good reason for being >> async. >> > >> >> >> >> Making ImageBitmap creation async means that you *cannot* use this as >> >> a replacement for drawImage source rectangles unless you know all >> >> possible source rectangles in advance. This is not possible for many, >> >> many use cases (scrolling through a bitmap would be one trivial >> >> example). >> > >> > >> > I am not sure I understand the problem. If you need synchronous >> behavior, >> > you can just make the app wait for the callback to be called. >> > >> > -Justin >> > >> >> >> >> On Tue, Dec 18, 2012 at 7:12 AM, Kevin Gadd <kevin.gadd@gmail.com> >> wrote: >> >> > Is it possible to expose the width/height of an ImageBitmap, or even >> >> > expose all the rectangle coordinates? Exposing width/height would be >> >> > nice for parity with Image and Canvas when writing functions that >> >> > accept any drawable image source. >> >> > >> >> > Thanks for the prompt action here, this looks like a straightforward >> >> > solution. >> >> > >> >> > -kg >> >> > >> >> > On Tue, Dec 18, 2012 at 7:03 AM, Justin Novosad <junov@chromium.org> >> >> > wrote: >> >> >> Thanks Ian. >> >> >> http://html5.org/tools/web-apps-tracker?from=7588&to=7589 >> >> >> >> >> >> On Tue, Dec 18, 2012 at 1:04 AM, Robert O'Callahan >> >> >> <robert@ocallahan.org> >> >> >> wrote: >> >> >>> >> >> >>> On Tue, Dec 18, 2012 at 6:57 PM, Rik Cabanier <cabanier@gmail.com> >> >> >>> wrote: >> >> >>>> >> >> >>>> Does it matter that this solution is in the image world and not 2d >> >> >>>> canvas? It seems that this will have a bigger impact on the >> browser's >> >> >>>> codebase since it spans images and canvas. >> >> >>> >> >> >>> >> >> >>> I think that's a good thing --- it's more generally useful. >> >> >>> >> >> >>> Note that Ian has adopted this approach (via an ImageBitmap >> >> >>> constructor). >> >> >>> >> >> >>> >> >> >>> Rob >> >> >>> -- >> >> >>> Jesus called them together and said, “You know that the rulers of >> the >> >> >>> Gentiles lord it over them, and their high officials exercise >> >> >>> authority over >> >> >>> them. Not so with you. Instead, whoever wants to become great among >> >> >>> you must >> >> >>> be your servant, and whoever wants to be first must be your slave — >> >> >>> just as >> >> >>> the Son of Man did not come to be served, but to serve, and to give >> >> >>> his life >> >> >>> as a ransom for many.” [Matthew 20:25-28] >> >> >>> >> >> >> >> >> > >> >> > >> >> > >> >> > -- >> >> > -kg >> >> >> >> >> >> >> >> -- >> >> -kg >> > >> > >> >> >> >> -- >> -kg >> > >
Received on Tuesday, 18 December 2012 16:36:48 UTC