Re: [fxtf-drafts] [filter-effects-1] What is the visual effect of filter() on the document element?

I have updated the proposal to take into account feedback from last time.

The new proposal treats the root element like any other stacking context, except that:
* The background paints onto the infinite canvas
* The output of its stacking context is blended with a solid-color white layer, if it's the root frame document of an application, and otherwise it blends with the enclosing stacking context of the containing document
* Order of application of graphical operations is not changed from spec 
* Takes into account transparency of iframes and even the root
* Supports clipping of root elements

Details and testcases:
https://docs.google.com/document/d/1IyRSnYISIUORuLnTkkOZN-42ypr70Naz-s-Mp4l4rxI/edit#

To answer two anticipated questions related to discussion:

Q: Why is there still a solid white layer for the root element of the root document? 
A: It's solid because of the desire to not directly blend any web content with "OS" pixels outside the developer's application. With the proposed approach, web content will blend with white, resulting in an opaque result (and a consistent result for web content, due to spec of white). If alpha is then applied to this result and mixed with OS pixels, that will work fine. If web content is embedded into a larger application, then this constraint could easily be relaxed, treating the root document like an iframe.

Q: (from prior WG discussion) Do iframes support clipping?
A: Chrome, for example, does support clip-path and CSS clip on the <html> element of an iframe.



-- 
GitHub Notification of comment by chrishtr
Please view or discuss this issue at https://github.com/w3c/fxtf-drafts/issues/282#issuecomment-431718402 using your GitHub account

Received on Monday, 22 October 2018 00:45:21 UTC