Squished Aspect Ratio in Emulators After Rotating Screen

[LtThunder]

On the way trying to make a compact game console build using Retropie, I've come across an issue via what seemingly is the aspect ratio for the emulators.

The 2.8 inch display that I am using is natively H x W (640 x 480), which means it comes out vertical, and I have to rotate it 270 degrees via the config.txt file in the boot folder. After taking off overscan I am able to boot to the retropie/emulationstation home screen where everything is still in the proper aspect ratio of 4:3 after the rotation. However, after booting into both drastic and the psx emulator offered by retroarch, it displays the game window centered in the middle, about 1/3 of the total size of the screen (it looks roughly like 640W x 160H).

I've tried by best to meddle with drastic settings (thought it doesn't have much), as well as retroarch, but retroarch is also having issues where it is not saving my configuration changes. The aspect ratio options inside retroarch as well is all out of wack, such as the 32:9, 3:4, and 4:1 options have the same ratio visually (just as an example, the other options are not outputting properly as well).

Is there any way of being able to display the game windows to the full size of the screen? I've tried manually changing the resolution of the screen from 480W x 640H to 640W x 480H through various config files, but to no avail.

Here are my specs:

Pi Model: Raspberry Pi Zero 2 W
Display: Waveshare 2.8in HDMI IPS LCD Display
RetroPie Version: v4.8
Built from: RetroPie image built using the Raspberry Pi Imager from the official website
USB Devices: 4-port USB hub, standard full sized keyboard, PlayStation 5 controller, USB C cable connected to the display for touch capabilities
Controller used: PlayStation 5
Emulators: DraStic and PSX (did not test out on other RetroArch emulators)

[LtThunder]

I ended up fixing the problem on my own.

The issue was that Drastic and Retroarch were trying to render the resolution at 640W x 480H, which would cause squishing issues.

By adding in:

  hdmi_cvt 480 640 60

Into the config.txt, I was able to give drastic another resolution to render at, solving the issue. For retroarch, I made the auto fullscreens resolution the 480W x 640H that the display was native to, which also solved the squishing.