NDS emulation rotate by 90 degrees to use whole screen

T0biasCZe

Pi Model or other hardware: 3B
Power Supply used: Samsung 2A charger or Huawei 3A
RetroPie Version Used (eg 3.6, 3.8.1, 4.1 - do not write latest):
Built From: build from github on raspbian pixel (Pre made SD Image on RetroPie website, Berryboot, or on top of existing OS etc.. - please provide the filename of any image used)
USB Devices connected: controllers bellow
Controller used: PS2 controller esperanza usb clone, usb snes controller
Error messages received:-
Guide used: -
File:-
Emulator: Drastic or desmume
Attachment of config files: -
How to replicate the problem: -
can drastic/desmume video output be rotated by 90degrees so it will use full screen? i tried many ways, (when i tried add video_rotate = 1 to retroarch but it only scaled it) but it doesnt worked.
one time it did something it only put the ds two screens side by side.
EDIT: also, i have 3,5 GPIO xpt2046 screen
how it looks normally:

How i would like to have it: (photoshoped)

thanks in advance

UnmaskdInsanity

@T0biasCZe I actually am looking into this same thing. I was able to successfully rotate the screen 90 degrees for only the desmume emulator everything else stays horizontal, however the touch screen doesn't work.(my issue with it) I have not been able to figure out how to get drastic to flip vertically as it does work with a touchscreen. I have an image of what my desmume looks like with the change.

You will want to access the NDS folder and look for retroarch config file. retropie/configs/nds/retroarch.cfg. This will load an override config for the NDS emulator when it launches. Next you will want to edit it. I connect with Windows and make the change in Notepad++. You will want to add the line line video_rotation = "1" or video_rotation = "3" above the #include line. That should turn your screen the other way.

Another way it could be edited is to go in through the Retropie settings and choose Retroarch. Once there settings -> video-> output-> video rotation. after you make the change here go back to the rtroarch main menu you should see the configuration file. save as new config. You should be able to use that new file in place of the retroarch.cfg.