Allow display flipping (for teleprompters etc)
I have a teleprompter, which requires me to flip (not rotate) the image on my secondary monitor.
Gnome Settings has a "Landscape (flipped)" orientation, but this is actually "Landscape (rotated 180)". Mutter does support this (see mutter#1693 (closed) for details) but it's not possible to enable it through the Settings panel.
Steps to reproduce:
- Open GNOME Settings
- Go to Displays and select "Orientation > Landscape (flipped)"
- Press Apply, see that the display is rotated but not flipped