Re: [css-masking] new value for 'mask-clip'

On Oct 26, 2012, at 11:23 AM, Robert O'Callahan <> wrote:

>> On Fri, Oct 26, 2012 at 9:19 PM, Dirk Schulze <> wrote:
>> The ellipse defined by this image would clip on the border box of the container. In absolute coordinates: cx=100, cy=100, rx=100, ry=100. Even with a value 'mask-clip: none', the ellipse would be the size of the container and clip to the border box of the container. But in the case above, you may want the ellipse mask the the whole group and not just the container.
> In CSS you can't do anything with that "whole group box". It doesn't really exist as a concept. (Except, arguably, influencing what you can scroll to in a scrollable container.) I'm not sure we want to introduce it just for the sake of masking here.

That is not correct, we do it for Filter Effects already. And even Firefox does it for mask, clip-path, filter. It is the union of all border boxes of all descendants and the element itself, like the rect for getComputedBoundingRect.


PS: The behavior of Firefox is described in an old specification draft. You may know this guy who wrote it :)

> It would be more convincing if you could come up with an actual use-case.
> Rob
> -- 
> “You have heard that it was said, ‘Love your neighbor and hate your enemy.’ But I tell you, love your enemies and pray for those who persecute you, that you may be children of your Father in heaven. ... If you love those who love you, what reward will you get? Are not even the tax collectors doing that? And if you greet only your own people, what are you doing more than others?" [Matthew 5:43-47]

Received on Friday, 26 October 2012 11:19:34 UTC