backend/wayland: use the parent's output scale

[nsailor]

When running the rootston compositor under another Wayland compositor (GNOME shell), the window does not use the native DPI but rather the DPI ratio is half that of the display.

If scaling is disabled from GNOME Settings, the resulting window has the correct DPI. It seems that the 'scale' attribute of the output of the host compositor affects the scale of the rootston window.

The DRM backend works fine with the HiDPI display.

Great job on this excellent library by the way!

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wlroots has migrated to gitlab.freedesktop.org. This issue has been moved to:

https://gitlab.freedesktop.org/wlroots/wlroots/-/issues/854

[ddevault]

Meh, I'm not too torn up about this. If you want to send a patch feel free.

[emersion]

If the Wayland backend is supported as an end-user feature, it makes sense to support HiDPI there.