I was wondering if anyone has managed to horizontally flip the display output. I am planning to update my arcade cabinet, which has been fitted with a mirror and a vertically mounted crt to create a tunnel effect. The crt has been physically changed to create the mirror effect. I was wondering if this effect could be created with somekind of script for the raspberry pi or specifically for retropie, for that is the only thing I will be needing it for to change the crt for an hdmi compatible flatscreen. If not, I rather stay with the crt, for it is as retro as can be.