Procedural renderer type glitches out on macOS

[peterdijkstra]

Main demo window works fine...

But problems start when things like comboboxes are being opened. When opening another example from the Examples drop down it looks like this

Happens on both the old rendering pipeline and the new URP

[goncalo]

Attempted a fix in bd446ba.

[peterdijkstra]

Seems to work 99% fine now! I am seeing some very slight very subtle glitchy things for 1 frame when manipulating the UI sometimes, but that's definitely not stopping this from being usable. I will try to capture a video of it later.

In any case, thanks!!

[mjkkirschner]

I am on Mac OS as well and see the subtle glitches as well, I would be interested in helping to track this down but don't know enough about imgui/unity procedural apis to be of much use.

It does only seem to happen when hovering over certain controls or interacting - moving windows does not seem to cause it.