As we highlighted in our initial XDC 2020 article, one of the presentations this year was from a Valve developer who is working on Gamescope.
Gamescope, something we revealed before across two articles (#1, #2), was started by Valve dev Pierre-Loup Griffais, who is one of the most prominent Linux people at Valve after joining them in 2012. Griffais has also been heavily involved in Valve's various external open source contracting, with things like ACO for Mesa and more.
Created as an evolution of steamcompmgr, the original SteamOS session compositing window manager but it's come a long way since then. Being a rewrite to be based on Wayland (and XWayland for what doesn't work with Wayland directly) rather than GLX, giving them much more direct control over everything with Vulkan. From the talk, Griffais mentioned how they began with using wlroots (a modular Wayland compositor library), from there they hacked away at it and merged it with a bunch of what was in steamcompmgr.
One of the aims here ended up being to have it work on a normal desktop, not just in a single-screen / single-activity like SteamOS did with steamcompmgr. The idea is that with Gamescope the game cannot interfere with your Linux desktop, while you also get more direct control over it for things like input, resolution, refresh rate and more. Griffais showed an example of Portal not working well with an Ultrawide monitor, and then when run with Gamescope at least the rendering was correct due to the sandboxing. Example below, launched as normal and then launched with Gamescope.
Another useful feature of Gamescope is that you can set it up so if a Gamescope window is out of focus, it throttles it down so you can interact properly with your desktop without the game sucking away all your juice. Something that would be seriously useful for lower powered devices / laptops and even on a high-powered PC there's certain games that bring your entire PC to a crawl when you ALT+TAB - so there's lots of uses there.
Plenty of work is still left to do, various polishing features still to be done but Griffais thinks it could be quite useful with a nice UI to go along with it. Lots more was talked about during the short presentation, it's well worth a watch if you're interested in one possible way of how games will be run on Linux in future.
You can see the video below, which begins at around 7:08:17. Our embed video should begin there for you to make it easy.
Quite an exciting project that will currently work with AMD drivers, and Intel is probably "not too far off". Eventually, once NVIDIA actually decide how they will be properly supporting Wayland and XWayland it might work there too.
Learn more about Gamescope on GitHub.