Implement wlr virtual pointer unstable protocol

[itaylor]

Description

Implements the wlr virtual pointer protocol:
https://wayland.app/protocols/wlr-virtual-pointer-unstable-v1

I was able to test it by running anvil:

RUST_LOG=smithay::wayland::virtual_pointer=debug WAYLAND_DISPLAY=wayland-1 cargo run --release --manifest-path anvil/Cargo.toml -- --winit

in one shell while in another running:

WAYLAND_DISPLAY=wayland-2 RUST_LOG=info cargo run --manifest-path test_clients/Cargo.toml --bin test_virtual_pointer

And I can see the events logged by anvil:

2026-05-20T04:12:54.472274Z DEBUG smithay::wayland::virtual_pointer: virtual_pointer: motion dx=4 dy=3 time=0
2026-05-20T04:12:55.472606Z DEBUG smithay::wayland::virtual_pointer: virtual_pointer: button button=0x00000110 state=Pressed time=0
2026-05-20T04:12:55.472654Z DEBUG smithay::wayland::virtual_pointer: virtual_pointer: button button=0x00000110 state=Released time=0
2026-05-20T04:12:57.473192Z DEBUG smithay::wayland::virtual_pointer: virtual_pointer: dispatching axis frame AxisFrame { source: Some(Wheel), relative_direction: (Identical, Identical), time: 0, axis: (0.0, 30.0), v120: Some((0, 360)), stop: (false, false) }

Anvil doesn't appear to draw a mouse pointer when used in this way, but the events do get logged as if they work. I also have a branch where I wired this into cosmic-comp and was able to use it successfully with wayland-clickdot and wlrctl to move the mouse around and show clicks. If there's some better way to have tested this within the scope of this repo I'm happy to add it.

AI Disclosure:
I used Claude Sonnet 4.6 to write this, but I read it and tested it myself. It is similar to the existing virtual_keyboard protocol implementation.

Checklist

• I agree to smithay's Developer Certificate of Origin.