Whole app locked to 16:9 on 18:9 screen

RetroArch Android devices
#1

Noticed on my Pixel 2 XL that Retroarch launches in 16:9 and is locked to the top of the screen (or left/right when rotated), with a large black bar at the bottom where the navigation buttons are. The navigation buttons slide on and off screen but the black bar remains.

To be clear, this is not an issue with any game or core resolution, but the entire app.

I’ve tried a bunch of different things. None of Retroarch’s settings have any effect. Forcing immersive mode doesn’t change anything either.

As far as I can tell, Google’s official literature basically states that apps need to be updated to support 18:9 screens.
https://android-developers.googleblog.com/2017/12/tuning-your-apps-and-games-for-long.html?m=1

Is there any chance of a fix for this issue?

Screenshot of the black bar at the bottom.

screenshot
screenshot.png1440×2880 187 KB

#2

Well, here on Samsung Galaxy S8, I have the option to take up the whole screen since the S8 uses 18:5:9 for aspect ratio. Well, I think it’s in the Android Settings somewhere.

#3

Other manufacturers have added a setting to force thier ultrawide aspect ratios in their custom versions of Android, but for whatever reason Google has decided that widescreen support should be left up to app developers. So such a feature is absent from stock Android and Google phones. It’s too bad, but it’s why I’m asking about this here.

Thanks for the suggestion though.

#4

Just as an update on this problem, I discovered that very slightly lowering the resolution causes the app to scale correctly. Using adb to change the resolution to 1440x2846, retorarch scales up correctly and fills the entire screen. Notably this actually makes the app wider overall than it is when incorrectly scaling at 1440x2880. At 2880 the black bar covers 168 pixels, leaving a total width of 2712, versus 2846 at that resolution.

This makes me think it’s some kind of math error.

I spent a bunch of time digging through the code but I couldn’t really figure out where such an error would be so… yeah. That’s all I’ve got.