On Thu, Mar 14, 2013 at 12:46 PM, Dean Jackson <d...@apple.com> wrote:
> I'm not sure I like this proposal. Why is canvas special? Why doesn't > <img> get an opaque attribute (or flag)? Why not every element? > > I don't think the performance benefit, which is mostly going to be on very > limited hardware, is worth changing the rendering model that is consistent > across every other part of the Web. > This is why a context creation parameter .... getContext("...", {alpha:false}) makes sense. It's labeling the content as having no alpha. Just like a JPG has no alpha. You don't specify the optimization, you just specify the content. The UA can decide if it can optimize on its own. > > Dean > > On 15/03/2013, at 4:53 AM, Stephen White <senorbla...@chromium.org> wrote: > > Hi Dirk, > > There have been at least five options considered, with contributions from > Chromium, Adobe and Mozilla so far. The moz-opaque idea was first floated > by Robert O'Callahan from Mozilla, and Ian Hickson offered to spec it if > another browser vendor wanted to implement it. I took him up on that > offer, and have made my humble effort to massage it into a concrete > proposal in the linked message above. > > After proposing it here, the alternative suggestion is to sync it up with > the WebGL syntax, and use a context creation object at getContext() time > rather than an attribute on the <canvas> element. I have no strong > feelings about this either way, and I'm working on a patch to try out the > WebGL approach (I already have a WebKit patch which implements the > platform-independent parts of the opaque attribute approach). However, if > we do go that way, I'd prefer not to make this proposal conditional on > changes to the WebGL spec, concerns which I've outlined over on what-wg. > > Stephen > > > On Wed, Mar 13, 2013 at 12:30 PM, Dirk Schulze <dschu...@adobe.com> wrote: > >> This is a very long thread and I did not see any conclusions or agreement >> on this thread. Can you summarize the topic and the status on the >> acceptance level please? >> >> Greetings, >> Dirk >> >> On Mar 13, 2013, at 9:15 AM, Stephen White <senorbla...@chromium.org> >> wrote: >> >> > Hi WebKittens, >> > >> > I'm planning to implement the canvas "opaque" attribute, as proposed >> here: >> http://lists.w3.org/Archives/Public/public-whatwg-archive/2013Mar/0109.html >> . >> > >> > This is an attribute that causes the allocation of an opaque backing >> store for <canvas>, allowing optimizations at the time the canvas is >> composited into the page, such as disabling blending and culling obscured >> content. It is based on the moz-opaque attribute currently shipping in >> Firefox. >> > >> > I'll be placing the feature behind the build-time flag >> ENABLE(OPAQUE_CANVAS). >> > >> > Let me know if you have any comments or concerns. >> > >> > Stephen >> > _______________________________________________ >> > webkit-dev mailing list >> > webkit-dev@lists.webkit.org >> > https://lists.webkit.org/mailman/listinfo/webkit-dev >> >> > _______________________________________________ > webkit-dev mailing list > webkit-dev@lists.webkit.org > https://lists.webkit.org/mailman/listinfo/webkit-dev > > > > _______________________________________________ > webkit-dev mailing list > webkit-dev@lists.webkit.org > https://lists.webkit.org/mailman/listinfo/webkit-dev > >
_______________________________________________ webkit-dev mailing list webkit-dev@lists.webkit.org https://lists.webkit.org/mailman/listinfo/webkit-dev