[csswg-drafts] [css-transforms-2][cssom-view] Define hit testing behavior for 3D transformed elements (#3997)

mikokm has just created a new issue for https://github.com/w3c/csswg-drafts:

== [css-transforms-2][cssom-view] Define hit testing behavior for 3D transformed elements ==
Related to #2325.
css-transforms-2: https://drafts.csswg.org/css-transforms-2/
cssom-view: https://drafts.csswg.org/cssom-view/#dom-document-elementfrompoint

The expected behavior of doing a hit test on a page with CSS 3D transformed elements is that the top-most element is returned first.

It seems that this is not how Chrome and Safari work. In this [testcase](https://bug1517388.bmoattachments.org/attachment.cgi?id=9066418), an element is rotated so that it intersects with its preserve-3d parent plane at z=0. The blue area is from the parent element (not link), and the white area is from the transformed child element (link). On Chrome and Safari both of the areas are clickable, on Firefox only the blue area is clickable.

This was found by [webcompat](https://github.com/webcompat/web-bugs/issues/21171). The hit testing behavior of 3D transformed elements should be defined, so that this browser interoperability issue can be fixed.



Please view or discuss this issue at https://github.com/w3c/csswg-drafts/issues/3997 using your GitHub account

Received on Monday, 3 June 2019 12:25:21 UTC