Re: [csswg-drafts] [css-anchor-position-1] position-visibility: anchors-visible should be clear about when is visibility determined (#12732)

> It doesn't? Safari does it during the style / layout loop afaict.

Blink does do it during the loop, via special internal versions of `IntersectionObserver`, like I mentioned above (that's what kDeliverDuringPostLayoutSteps does).

> But that's not what the spec says to do (that accounts for a lot more than scrolling overflow, like overflow: clip, clip-path, etc).

Hmm I think you're right, sorry about that. So consistency with `IntersectionObserver`'s notion of clipping (which includes clip-path and so on) is an advantage. Upon further reflection, I  actually prefer not having to implement and optimize a whole new code path that will be hot during scroll intersections. A lot of effort went into optimizing `IntersectionObserver`.

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Received on Monday, 29 September 2025 21:33:05 UTC