Rendering of floating polygons that overlay the map, for UI elements

[daseinlaser]

Hello,
Are there any ways to use Maplibre-native (Android) to overlay floating polygons over the displayed map? For example a rectangle, drawn over the map in a fixed location relative to the screen. If not, I plan to either extend Maplibre-native with such functionality, or to overlay the Maplibre MapView with my own UI view in my application. I am pretty sure that one can draw polygons on the map using Maplibre-native, but I believe that those are positioned according to location within the map.

[stefankarschti]

Hi! I'm working on enabling the users to emit custom drawables in custom drawable map layers. Various primitive types can be created, I started with polylines. Matrix is arbitrary, therefore you could draw polygons relative to the viewport if that's what's needed.
CC @louwers @sjg-wdw
WIP PR: #1754
Check out issue #1735, comments welcome!