Vertically mirroring the screen in LibGDX

I’m developing a game in which the screen layout is different for right and lefty players, so i’ll put a button in it to mirror the screen vertically.

For displaying textures and fonts, i use a single scene2D stage with actors and labels. The stage’s viewport type is FitViewport.

How can i swap between the right and left layouts?
Is there something already done to do it on the viewport-side?

Is it only a matter of switching coordinates from bottom-left to bottom-right?
I can do that on the viewport camera, but what about all the textures? How can i change an actor’s coordinate system?

Thank you all