Re: Filters on HTML question

Dean Jackson was going to draft a preliminary spec for CSS filters but he
didn't submitted it yet.

I believe the thinking was to define filter similar to how Explorer defines
them and not similar SVG like your proposal.
So, more like:

filter: emboss(params), dropshadow(params),...

We haven't discussed the compositing but your suggestion sounds reasonable.


On Wed, Mar 30, 2011 at 9:28 AM, Patrick Dengler <> wrote:

> I know some good progress was made here.  I believe last we talked there
> were some input/layering issues around filters on HTML. Have we considered:
> (If we follow the painting , from draft spec)
> How the 'filter' property applies to content formatted by CSS (e.g HTML)
> The application of the ‘filter’ property to an element formatted by CSS
> establishes a pseudo-stacking-context the same way that CSS 'opacity' does,
> and all the element's boxes are rendered together as a group with the filter
> effect applied to the group as a whole.
> The ‘filter’ property has no effect on the geometry of the target element's
> CSS boxes, even though ‘filter’ can cause painting outside of an element's
> border-box.
> The compositing model follows the SVG compositing model: first any filter
> effect is applied, then any clipping, masking and/or group opacity. These
> effects all apply after any other CSS effects such as 'clip'. As per SVG,
> the application of ‘filter’ has no effect on mouse event hit-testing.
> =>Then if we created a filter shortcut syntax:
>        filter= url(#) {shortcut}
>                none - presumes ‘in’ expressed by SVG filter; and if SVG
> Filter has none, it presumes SourceGraphic (which maps to ‘content’ below)
>                background – overrides ‘in’ on SVG Filters using the
> background layer in HTML
>                border – overrides ‘in’ on SVG Filter and uses the border
>                content – includes all content / children of the elements
> that are in that z-index
> so  filter:url(#textShadow) content
> I'd love to hear feedback here and make some movement (unless I missed
> some)

Received on Wednesday, 30 March 2011 16:53:25 UTC