[css-round-display][media-queries] Media query polygons

Hi,

I was reading the spec for CSS Round Display and saw the note about how to
detect different shape screens. I'm not aware of the technical limitations
for media queries so ignore me if I'm talking nonsense.

Currently the spec uses (device-radius: 50%) which is probably going to be
the most common use-case. I was wondering if, to keep it simple but still
powerful, the other shapes could be queried by using the same syntax as
clip-path? That would allow it to be as simple or complex as required, and
for some use-cases the same shape could be used elsewhere with ease.

Of course, I may be going over old ground but thought it might be worth
dropping a note.

Cheers,
Shane