- From: Tab Atkins Jr. <jackalmage@gmail.com>
- Date: Thu, 13 Aug 2015 14:19:39 -0700
- To: Amelia Bellamy-Royds <amelia.bellamy.royds@gmail.com>
- Cc: "L. David Baron" <dbaron@dbaron.org>, "www-style@w3.org list" <www-style@w3.org>, "www-svg@w3.org list" <www-svg@w3.org>, Dirk Schulze <dschulze@adobe.com>
On Wed, Aug 12, 2015 at 4:23 PM, Amelia Bellamy-Royds <amelia.bellamy.royds@gmail.com> wrote: > I do not know of any user agent that has implemented transitions from one > SVG gradient to another (except by animating the SVG gradient <stop> > elements themselves), so changing the draft text should not be problematic. > > (I don't have an Apple device to test with at the moment; if someone wants > to give it a go to confirm please let us know.) > > The SMIL behavior was to animate changes in a url(#paint) reference in > discrete switches. Many implementations are currently buggy even doing > that, and I'm not sure whether any do it for CSS animations/transitions yet > (i.e., whether they animate it in the sense that the change is affected by a > transition delay or step function, or applies at all when specified in > keyframes). > > As much as it sounds nice to be able to transition between SVG gradients, I > agree with the arguments relating to the lack of specifiable intermediate > values. The only way you could define an intermediate value would be if you > mapped both initial and final SVG gradients to CSS gradient functions and > transitioned the functions. That is currently not practical because there > are features of SVG gradients which cannot yet be represented in CSS > gradient functions. It also just sounds like an implementation headache: > what if the DOM or styles for the SVG gradient elements were also changing? Nah, they'd just fall into the generic <image> bucket, and cross-fading between animated elements is well-defined. > I like the idea of applying cross-fade transitions to SVG paint server > content. That should address most use cases with acceptably smooth results. > It may be worth discussing how the scaling as well as fading transition > would apply to an SVG pattern (i.e., is it treated as a single image or a > tiled image? if tiled, how do you incorporate pattern transformations?). Nothing special needs to be done for transitioning - it falls out of CSS's handling of SVG paint servers. And that's defined by the Images 4 spec. ~TJ
Received on Thursday, 13 August 2015 21:20:26 UTC