Pens on KDE Plasma 6.3+ under Wayland don't reach the app: winit 0.30 binds no
Wayland tablet protocol (zwp_tablet_v2), and since Plasma 6.3 KWin no longer
emulates pointer input for such clients (kwin!6336), so the pen moves KWin's own
cursor while the window gets no motion or presses. The fix is upstream (winit
0.31's tablet input, winit#4318, once eframe moves to it). docs/development.md
and the README give the workarounds: run under XWayland (WAYLAND_DISPLAY=), or
set KWIN_WAYLAND_EMULATE_TABLET=1 for the session.
On our side, a pen or finger (winit Touch, emulated as a mouse by egui-winit)
lifts with an egui PointerGone in the same frame. A tap whose press and lift
arrived in one frame had no hover position, so the canvas ignored it, and a
drag ending without a pointer position ended at the canvas's centre. The press
and double-tap now fall back to the interact position, and the release to the
last position seen during the drag. Headless frame tests replay the events a
pen produces: a stroke with pressure reaching Use Pressure Pen, and a one-frame
tap that selects without moving (fails without the fix).
ROADMAP: Last updated, the Platforms row, the hardening gap and the graphics
processor/input bullet (pen pressure reaches the tools on Windows only).
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
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