- From: Tab Atkins Jr. <jackalmage@gmail.com>
- Date: Wed, 20 Apr 2011 12:51:52 -0700
- To: Dean Jackson <dino@apple.com>
- Cc: public-fx@w3.org
On Wed, Apr 20, 2011 at 12:12 PM, Dean Jackson <dino@apple.com> wrote: > On 20/04/2011, at 11:44 AM, Tab Atkins Jr. wrote: >> On Tue, Apr 19, 2011 at 6:14 PM, Dean Jackson <dino@apple.com> wrote: >>> Then I was thinking that these generator effects are similar to other parts of CSS, in particular gradients. There have been some proposals in this area. For example: >>> >>> - WebKit's -webkit-canvas value, which allows an element to use a canvas element as an image in background, border, whatever. >>> - Mozilla's -moz-element, which does the same but with the rendering of any element >>> >>> Examples of generators may be: >>> >>> - checkerboards >>> - stripes >>> - noise >>> - star shines >>> >>> They don't sound too useful in isolation, but graphics artists may feel otherwise. Anyway, the important part of this message is the 3rd paragraph. I don't want to complicate the syntax or implementations. "SVG" filters provide the functionality, so it definitely isn't essential. >> >> Yup, these are just generated images, and should probably be defined >> in the Image Values module. > > Excellent. Are you responsible for that spec? And will you take this on - whatever that means, maybe an email to www-style? Yes, and yes. >> Of the existing Filter primitives that do this, feFlood is already >> doable with the image() function (just doing "image(blue)" produces a >> pure-blue image, because it's the fallback color for an empty list of >> image declarations). feImage is done with the url() function. >> feTurbulence is something we should add, as perlin noise is really >> useful to add a bit of non-uniformity to designs (I've seen a lot of >> recent stuff where a design is done just with gradients, but with a >> noise image laid on top); it should probably be a perlinnoise() >> function or something. > > I think noise() or turbulence() are good names. I don't see a need to be so exact unless we're going to add multiple algorithms. Okay. >> Stripes are already doable with linear gradients. It turns out that >> you can get a checkerboard with just two linear gradients combined >> together <http://leaverou.me/css3patterns/>. > > I'd suggest a new value for this. Just because it is possible doesn't mean we should encourage it. Do you see a chessboard and think "oh, overlapping rotated repeating gradients with hard edges"? I don't disagree; the patterns on that page are all pretty non-obvious at first, until you realize that it's just (ab)using gradients to build things out of right triangles. The only real question is if checkerboards are a useful enough image type to bless with syntax. I'll bring this up in a separate thread. >> I dunno about >> haloes/star shines, but I'm not averse to them if they're useful. > > It's not terribly common, but I can imagine people wanting to bling-up their site header with a little sunburst (which animates across the text as the drop shadow moves in sync). Or use <blink>. > > But I'm a big fan of starting small, especially if you know that you're not making enhancements hard to add at a later stage. So probably no need for this now. Kk. Yeah, new image types aren't hard from a spec standpoint. It's just a question of what's performant to generate with platform libraries. ~TJ
Received on Wednesday, 20 April 2011 19:52:39 UTC