New Wayland Protocol Proposed For Fractional Scaling
wp-surface-scale-v1 is similar to the recently proposed wl_surface.scale, but while the latter is limited to integer scaling, wp-surface-scale-v1 is designed to support fractional scaling. The wl_surface.scale motivation is for accessibility features like a screen magnifier, for VR headsets to render surfaces close to the eye at a higher scale, and HiDPI screenshots on LoDPI screens.
The wp-surface-scale-v1 proposal comes from Kenny Levinsen and there is also an experimental compositor implementation of it for wlroots and the Sway compositor as well as some test client code.
More details on this proposed Wayland extension for fractional scaling of surfaces via this merge request.