[webvtt] Allow compositing and blending properties on `::cue` (#518)

SebastianZ has just created a new issue for https://github.com/w3c/webvtt:

== Allow compositing and blending properties on `::cue` ==
The [Compositing and Blending spec.](https://drafts.fxtf.org/compositing-2/) defines different properties related to compositing and blending the backgrounds of an element or the element as a whole with its backdrop. Specifically, those are `background-blend-mode`, `mix-blend-mode` and `isolation`.

I think, especially the first two make sense to support.
`background-blend-mode` allows to apply different blending effects between the backgrounds of an element. So it goes hand in hand with the properties related to the `background` shorthand, which are already supported. (And note that this property _is_ actually already supported in Gecko.)
`mix-blend-mode` allows to apply different blending effects onto the element itself with its backrop.
`isolate` puts an element into an isolated group for compositing. Though I don't know if that's actually useful in the WebVTT context.

Sebastian

Please view or discuss this issue at https://github.com/w3c/webvtt/issues/518 using your GitHub account


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Received on Thursday, 17 August 2023 21:15:58 UTC