- From: Robert O'Callahan <robert@ocallahan.org>
- Date: Fri, 13 Dec 2013 18:24:14 +1300
- To: Rik Cabanier <cabanier@gmail.com>
- Cc: James Robinson <jamesr@google.com>, www-svg <www-svg@w3.org>, www-style list <www-style@w3.org>, "public-fx@w3.org" <public-fx@w3.org>
- Message-ID: <CAOp6jLaC9tfMuSFVy8iOfbkHSRY8UrHYpduo4AmQCzs+Moj7rQ@mail.gmail.com>
On Fri, Dec 13, 2013 at 4:50 PM, Rik Cabanier <cabanier@gmail.com> wrote: > On Thu, Dec 12, 2013 at 7:29 PM, Robert O'Callahan <robert@ocallahan.org>wrote: > >> On Fri, Dec 13, 2013 at 4:13 PM, Rik Cabanier <cabanier@gmail.com> wrote: >> >>> No, the spec should not refer to blogs. Also, this is not 'potentially' >>> useful as the absence of this description has caused confusion in the past. >>> >> >> I agree with James. Having the spec define behavior that is never used by >> any Web feature is very confusing. >> >> Section 4 is not really needed at all since the HTML5 canvas spec defines >> the canvas compositing behavior. >> > > Can you point where that is defined in the canvas spec? > http://www.whatwg.org/specs/web-apps/current-work/multipage/the-canvas-element.html#drawing-model > > >> If you want the Compositing and Blending spec to define new compositing >> modes for canvas, then define a list of operators that the HTML canvas spec >> can refer to, but don't define globalCompositeOperation here. Don't even >> mention canvas here. >> > > It's needed because the canvas spec doesn't say anything about how > compositing should happen. > I don't want to break canvas by removing this. > All you need to define for canvas is the per-pixel compositing behavior. > > Another very important reason is also that if this property/behavior is >>> included in the spec, the W3C patent policy will apply. >>> >> >> Describing something in a W3C spec that is not actually used by any >> features in that spec, just so we can get the patent policy to apply to it, >> borders on bad faith. >> > > It *is* being used. > Where? Pointing to "clip to self" saying "don't do this" does not constitute a use. > Also, future spec might want to refer to this. Another example is the > proposal for masking in canvas which has an option for clip-to-self. It > would be unfortunate that we would have to rev the compositing spec to > progress canvas or filters. > If a future spec will use it, the future spec can define it. Any use of clip-to-self will have to define what the clip-to-self region is for each drawing operation, which is not necessarily easy to do. It certainly shouldn't be done by saying the clip-to-self region is where alpha > 0, for the reasons James pointed out near the beginning of this thread. Rob -- Jtehsauts tshaei dS,o n" Wohfy Mdaon yhoaus eanuttehrotraiitny eovni le atrhtohu gthot sf oirng iyvoeu rs ihnesa.r"t sS?o Whhei csha iids teoa stiheer :p atroa lsyazye,d 'mYaonu,r "sGients uapr,e tfaokreg iyvoeunr, 'm aotr atnod sgaoy ,h o'mGee.t" uTph eann dt hwea lmka'n? gBoutt uIp waanndt wyeonut thoo mken.o w
Received on Friday, 13 December 2013 05:24:47 UTC