Prefer native Wayland video driver on Linux when running under Wayland sessions

[HeribertYavuz]

Native Wayland Support for osu! (lazer)

Problem / Background

Currently on Linux, osu!lazer under Wayland sessions often defaults to running through XWayland unless the user explicitly sets SDL environment variables (SDL_VIDEO_DRIVER=wayland or SDL_VIDEODRIVER=wayland).

Running through XWayland on modern Wayland desktop environments introduces several downsides:

• Extra input and display latency (especially noticeable in rhythm games).
• Blurry fractional scaling on high-DPI displays.
• Occasional cursor confinement or tablet coordinate mapping quirks.

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Proposed Solution

When launching on Linux under an active Wayland session (WAYLAND_DISPLAY is present), prefer the native Wayland driver by default unless the user has already specified an explicit override:

if (OperatingSystem.IsLinux() && !string.IsNullOrEmpty(Environment.GetEnvironmentVariable("WAYLAND_DISPLAY")))
{
    if (string.IsNullOrEmpty(Environment.GetEnvironmentVariable("SDL_VIDEO_DRIVER")))
        Environment.SetEnvironmentVariable("SDL_VIDEO_DRIVER", "wayland,x11");

    if (string.IsNullOrEmpty(Environment.GetEnvironmentVariable("SDL_VIDEODRIVER")))
        Environment.SetEnvironmentVariable("SDL_VIDEODRIVER", "wayland,x11");
}

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Why wayland,x11?

Using "wayland,x11" instructs SDL to attempt initializing via the native Wayland driver first, while retaining automatic, seamless fallback to X11/XWayland if the compositor or environment does not support it. It also respects user-defined overrides.

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Implementation / Reference Branch

The change has been prepared and tested here:

• Branch: feature/wayland-support