Robert Flack

> In this case, we're just using the promise for its timing aspect. Additionally, the promise can be passed an argument which includes the completion status of the scroll so...

> > Ok, I also wondered about that, but @flackr wrote Web Animations 1, and some things I needed to update were actually there, so not sure whether this was...

I think this also needs to add the animation trigger to [The Animation interface](https://drafts.csswg.org/web-animations-2/#the-animation-interface).

Apologies I think this is a duplicate of #9452 so I'll close in favor of that tracking issue which has a bit more history.

> * Any reason to prefer `offset( ) offset( )` over `offset( , )`? I guess the latter maps better to a single delay value that is expected today, or...

> It used to be common for scroll-linked animations, which were all based on `ScrollTimeline`-like implementations, to use a start offset (delay) and pixel-duration (duration), rather then an end offset...

I suspect this is a nice to have but that we could not support the new properties and values in the short-hand for the initial version.

@dbaron I see you did some analysis of usage of `auto` for https://github.com/w3c/csswg-drafts/issues/7431#issuecomment-1177688302. My read from that is that you didn't find `@keyframes auto` in your Cluster Telemetry runs suggesting...

> There are a bunch of demos I built for https://www.bram.us/2023/10/23/css-scroll-detection/ that depend only on the _active_ scroll direction (and also scroll speed). Once you stop scrolling, the effect no...

> +1 to [@flackr](https://github.com/flackr). That's usually the case, so probably solving velocity will solve more cases. If we want to persist the velocity past the `scrollend` point then we should...