[filter-effects] Filter primitive subregions and input clipping

Hi folks,

Iím wondering why the spec says that filter primitive subregions clip their input.

Implementations donít do it, and Iím struggling to find a benefit of it. IMO, we should remove this requirement.

I agree with Stephen Whiteís statement last time this was discussed [1]:
"I suppose you could make the argument that if you had only output clipping, you could always achieve input-and-output clipping by inserting a no-op node (e.g., FEOffset) with the filter primitive subregion set to the same values as the child node, e.g.  http://jsfiddle.net/C6zSD/3/. Whereas if you have input-and-input clipping, there's no easy way to achieve output clipping only."

According to my tests (posted on a related spec bug [2]):
- Safari, Firefox, and Chrome do not clip the input to a filter primitive to its primitive subregion. IE11 was inconclusive; I think I ran into a different bug.
- Safari, Firefox, IE11, and Chrome all clip the input to a filter to its filter region.



[1]: http://lists.w3.org/Archives/Public/public-fx/2013JulSep/0082.html
[2]: https://www.w3.org/Bugs/Public/show_bug.cgi?id=26432

Received on Monday, 3 November 2014 23:31:45 UTC