rust-windowing/glutin

scale_factor under KDE + wayland reported as integer value

Closed this issue · 2 comments

giox069 commented

Recently KDE introduced support for monitors with different scale factors under Wayland. Scale factor under KDE can be fractional (under GTK the scale factor is an integer value).
I have two monitors, one with 100% scale factor, and one with 150% scale factor. I'm running cargo run --example window under KDE+ wayland.

When I move the example window from the 100% sf monitor to the 150% sf monitor, the received events erroneously reports a scale factor of 2 instead of 1.5:

WindowEvent { window_id: WindowId(Wayland(WindowId(94893836137024))),
 event: ScaleFactorChanged { scale_factor: 2.0, new_inner_size:
 PhysicalSize { width: 1600, height: 1200 } } }
maroider commented

AFAIK, KDE is using their own protocol extension to implement this, as the core protocol only supports integer scaling, and I believe we only use the latter thorough SCTK.

kchibisov commented

No, this protocol about output. There's no fractional scaling on Wayland in any form yet. Once it'll be added in wayland-protocols we can reopen this. I think there's some ongoing work about fractional scaling, but nothing standard.

Scaling factor of 2 is expected and how every compositor out there works.

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