Wine Wayland gains fractional scaling support

The Windows compatibility layer Wine is expanding its Wayland support some more, with fractional scaling support landing recently.

Quick-reminder: Valve's Proton is forked from Wine, it's one of the big bits of tech behind the scenes that allows so many thousands of Windows games to run so nicely on Linux / SteamOS systems like the Steam Deck. Along with the Steam Machine and Steam Frame coming this Summer.

In a code request titled "winewayland: Implement fractional scaling protocol", developer Etaash Mathamsetty mentioned:

The idea behind this is to use fractional scaling to make it appear as if the Wine environment is running at the user-specified DPI in winecfg while keeping the windows looking crisp. This enables users to have different fractional scales per display under wine without causing blur. This matches the behavior under XWayland and is actually better than the XWayland behavior when using multiple displays with different fractional scales.

FWIW: Mutter has a bug with its implementation of fractional scaling that has been recently fixed in case this compositor is being used to try this implementation: https://gitlab.gnome.org/GNOME/mutter/-/work_items/4834

With this code getting merged on Monday, June 15th, it should be ready for the next Wine release of Wine 11.12 that's due out around June 26th.

Wine 11.11 that was released last week also had support for layered windows in the Wayland driver, so Wine's full Wayland support is really starting to come together now. Hopefully it won't be long before everything works fully.