Screen rotation on a Pi4

[Mellow]

I did dredge the posts but could not find a clear and definitive solution for rotating RetroPie UI and ROMS on a Pi 4.

This seems to me like a rudimentary requirement since many arcade games were designed in portrait orientation.

I am building a full-size 1up cabinet and now need to mount my 3:4 monitor but first have to get it to work outside the cabinet.

Any help for a new first time Pi / RetroPie user?

[tommkell]

Think you just need to fix the aspect ratio in scaling, these vertical games would have been on a 4:3 monitor turned on it's side, so you'll need a 3:4 ratio. I changed this in video options then set overrides to game overrides so no other normal games were effected, hope this helps

[tommkell]

You can fill the empty sides of the screen with bezels then. These can be hit and miss, I ended up having to modify some to suit the arcade 1 up screen.

[sleve_mcdichael]

DISCLAIMER: I've not done this myself. This is info I've found on the web. From: https://pimylifeup.com/raspberry-pi-rotate-screen/

This is real easy in a Pi 3, you just have to add a line in /boot/config.txt:

display_hdmi_rotate={N}
# where {N} is an integer from 0-3

Unfortunately this method doesn't work with the Pi 4's hardware accelerated video, so you can either disable that (which may or may not open up a whole 'nother can of worms), or else I think you need to use some features only available in the "full" desktop install, not the "lite" terminal-only version that RetroPie is based on.

You can install the full desktop with the following commands:

sudo apt install --no-install-recommends lxde
sudo apt install xorg raspberrypi-ui-mods rpi-chromium-mods

Once that's done, you have a couple of options. You can adjust the rotation from within your brand-new desktop GUI, or you can still use the terminal now that you should have the xrandr command available.

From the desktop: select the Pi icon -> preferences -> screen configuration. Right-click the display you want to edit. Select orientation and then select your desired rotation. You have ten seconds to click ok before the change will be reverted.

From the terminal: you will need to make use of the new xrandr (X-window Resize AND Rotation) command, not available in Raspbian lite (or at least on my Pi 4 with RetroPie I got a "command not found" error) with the following:

DISPLAY=:0 xrandr --output HDMI-1 --rotate {orientation}
# where {orientation} is one of: normal, left, right, inverted

(Use HDMI-2 to rotate the second screen.)

EDIT: I supppse you could try:

sudo apt install lxrandr

...and see if that's enough, if you don't want the full desktop. I'm not sure if that will have everything you need, but it's one of the dependencies for lxde so it'll still be installed anyway if you go Full Monte. Shouldn't hurt to try it out. I mean, you have a backup, right?

[dankcushions]

@sleve_mcdichael xrandr only works when X is running, so the setting won't persist in a pure commandline/framebuffer environment, like retropie on the pi. as soon as you exit the desktop, everything is back to how it was, as far as i'm aware.

you can attempt to run retropie within X, of course, but that's not a supported configuration. however it's probably the path of least resistance for non-standard display setups (rotated, CRT, etc), as xrandr is so powerful...