- From: Rik Cabanier <cabanier@gmail.com>
- Date: Fri, 6 Dec 2013 09:28:12 -0800
- To: Dirk Schulze <dschulze@adobe.com>
- Cc: "public-fx@w3.org" <public-fx@w3.org>, www-svg <www-svg@w3.org>
- Message-ID: <CAGN7qDCUT7Vvm+jZFS+K3J4NRV6ObSpGB2afWyeXHJ+c3pU3iA@mail.gmail.com>
On Fri, Dec 6, 2013 at 5:16 AM, Dirk Schulze <dschulze@adobe.com> wrote: > Hi, > > The SVG WG resolved at the F2F in Tokyo this summer that <feBlend> in > Filter Effects should support blending without compositing. This shall > avoid double compositing as it can happen in combination with > BackgroundImage today. [1] > > We did have some difficulties to define the exact way to disable > compositing. There are two different proposal so far: > > 1) Support all compositing operators on <feBlend> > > The idea is that we actually do not disable compositing but allow the > author to use a different compositing operator. The ‘mode’ attribute could > be extended to support compositing modes as well: > > <blending> = [normal | multiply | screen | darken | lighten] || [over | in > | out | atop | xor] > > which could look like this: > > <feBlend mode=“screen atop” in2=“BackgroundImage” /> > Unfortunately, this does not solve the problem. We want to option to skip the compositing step, not to replace it with another one. > > (The compositing values could be replaced by the keywords used by Canvas.) > > 2) Create new attribute ‘compositing' > > SVG does not support boolean attributes yet. Therefore the attribute > ‘compositing' would need values like ‘composite’/’no-compositing’ or simply > ‘true’/‘false’. > > With this attribute the compositing step can just be omitted completely or > switched to source-over compositing following the formulas from CSS > Compositing and Blending. > > > Any preferences? > I think only option 2 is viable. > > [1] http://dev.w3.org/fxtf/filters/#issue-9d31c6c7 >
Received on Friday, 6 December 2013 17:28:40 UTC