Re: generators in filters (or maybe even "anywhere there are images")

Hi Dean,

Love the onion link!

Most people don't associate generated images with filter effects so I agree
with Tab that these belong in the image values module and not in filters
module.
It's unclear to me if they're useful enough to warrant their own CSS syntax
as opposed to just use SVG.

Rik

On Tue, Apr 19, 2011 at 6:44 PM, Tab Atkins Jr. <jackalmage@gmail.com>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.
>
> 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.
>
> 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 dunno about
> haloes/star shines, but I'm not averse to them if they're useful.
>
> ~TJ
>
>