macos high window content flickering

[Sega-Zero]

Running a GUILiteDemo on macOS Monterey and see a lot of flickering, see a screencast below

https://user-images.githubusercontent.com/2203199/170736990-d0a73d4e-fa59-4ff4-a896-3ab073c05ef9.mp4

it's a bit slower at the time I was recording it, but after some idle running, the flicker increases. Also, rendering stops when selecting a menu.

[idea4good]

Thanks for your issue report, maybe we use a wrong rendering API for macos