1655224 - (backface-visibility-bugs) [meta] Improve backface-visibility spec and implementation

Status: NEW

(Core :: Web Painting, task, P5)

Description

[Matt Woodrow (:mattwoodrow)]

The current spec defines backface-visibility as potentially affecting the visibility of the ‘element’ with the property, but it seems to make more sense as stacking-context grouping property that applies the effect to the element and all descendants.

WebKit/blink currently implement backface-visibility as a compositing layer, which hides the backface of the element and most descendants, but not descendants whose containing block is an ancestor of the element with backface-visibility:hidden. This can allow descendants to not be hidden, even when the element with backface-visibility:hidden is a stacking context.

Gecko implements backface-visibility as an element-only effect, and doesn’t apply to any descendants. The exception is if the element creates a stacking context through some other property (usually transform), in which case the backface of the stacking context as a whole is hidden.

The current WebKit/blink behaviour is dependent on implementation specific details, and the Gecko behaviour has known webcompat issues.

This bug tracks figuring out the best way to resolve this, and then the implementation of the solution.

Explainer doc, including proposed solutions: https://docs.google.com/document/d/12C5heW6ecNJKiBoWByZtBHjzTgBQf3Z0aoQfeO1wexQ

Comment 1

[BugBot [:suhaib / :marco/ :calixte]]

The meta keyword is there, the bug doesn't depend on other bugs and there is no activity for 12 months.
:tnikkel, maybe it's time to close this bug?

Comment 2

[BugBot [:suhaib / :marco/ :calixte]]

The meta keyword is there, the bug doesn't depend on other bugs and there is no activity for 12 months.
:tnikkel, maybe it's time to close this bug?

Comment 3

[Timothy Nikkel (:tnikkel)]

Please bugbot, just stop filling my inbox.