Add more involved multi-tap scaling filters

[niarbeht]

It's totally not a bug, I swear!

Your example in the readme indicates gamescope -w 1920 -h 1080 -W 3440 -H 1440 -b -- %command%, but if you want to have a good time, try gamescope -w 3840 -h 2160 -W 1920 -H 1080 -f -- %command%.

Consequently, you get a downscaled image. This is to be expected, but it makes me wonder if it could possibly act as a sort of backdoor "dynamic/virtual super resolution" feature. With a good and fast downscaler, it could bring that missing feature to systems using Gamescope, regardless of vendor support.

[emersion]

What is the use-case for downscaling? Mitigate aliasing on games which don't have anti-aliasing?

[niarbeht]

What is the use-case for downscaling? Mitigate aliasing on games which don't have anti-aliasing?

It's the same use-case that Nvidia's Dynamic Super Resolution and AMD's Virtual Super Resolution solve. With a good downscaler, it can get better results than regular anti-aliasing, especially on fine details.

I'm just noting that with the addition of a well-picked downscaler, this could be a neat feature. I'm not sure if it aligns with gamescope's mission, but if you're gonna have integer upscaling as an option, fancy downscaling might be a neat option, too.

[emersion]

Well, I don't see why not if it's just an option like integer scaling.

[Saroumane]

Hello, I concur : downscaling is a very nice feature, and gamescope is a fantastic tool !
This is my use case : I play 240p Steam games (mostly Cave / Psikyo shmups) on CRT TV, to have the "best" (read : original) possible picture.

First, gamescope + Xwayland have the feature to be "bugfree" with my CRT (I had many hiccups with Xorg), and I just have to setup an edid file, there is no need to handle a complex xorg.conf.

Regarding the downscaling feature, some games have originally a 320x240 resolution, but their console/steam port is in 640x480 (example Mushihimesama from Cave). So I launch the game with gamescope in its "native" 640x480 resolution, scaled down to my 320x240 for my CRT :
~/scripts/gamescope/build/gamescope -f -w 640 -h 480 -W 320 -H 240 -- "$@"

For the record, I have made a guide on Steam describing the whole setup (I don't know if such links are allowed, tell me if I have to remove it)
https://steamcommunity.com/sharedfiles/filedetails/?id=2374056460

[Plagman]

Getting easy super-sampling through downscaling without having to resize your whole desktop was an intended application for this, so I wouldn't call it accidental. Glad it's working well for you!

[Plagman]

I guess we can keep it open as a feature request for more involved multi-tap scaling filters.

[dkoukola]

I have tried to implement some experimental downscaling filters in PR #2024.