Bug 395818

Summary:	Inaccurate mouse input in Nexuiz on Wayland
Product:	[Plasma] kwin	Reporter:	Rainer Finke <rainer>
Component:	input	Assignee:	KWin default assignee <kwin-bugs-null>
Status:	RESOLVED UNMAINTAINED
Severity:	normal	CC:	bugseforuns, notuxius
Priority:	NOR
Version:	5.16.90
Target Milestone:	---
Platform:	Arch Linux
OS:	Linux
Latest Commit:		Version Fixed In:

Description Rainer Finke 2018-06-24 15:47:26 UTC

When playing nexuiz (nexuiz-sdl) on Plasma on Wayland, the mouse input in XWayland is often inaccurate. Sometimes the mouse "jumps", resulting in an uncontrollable movement, I would describe it as a ~180° degree movement. Another issue is that the mouse is getting slower or is even blocked when continuously trying to move e.g. to the right side. I noticed this behavior as well in several proprietary games.

Linux 4.17.2
wayland 1.15
xwayland 1.20.0
libinput 1.11.1
sdl2 2.0.8
Plasma 5.13.1
kwin-git 5.14 (2018-06-24)
kwayland-git 5.14 (2018-06-24)

Comment 1 Alexander Mentyu 2018-06-26 16:05:47 UTC

Related bugs https://bugs.kde.org/show_bug.cgi?id=395815 https://bugs.kde.org/show_bug.cgi?id=388885

Comment 2 Rainer Finke 2018-06-26 19:08:45 UTC

The linked bugs are only partially related. I've tested the fix, but the mouse "jump" is still there either in the game and in the menu. It is impossible to control the mouse as of this bug.

Comment 3 Rainer Finke 2018-06-26 21:48:02 UTC

I've tested the patch of the other 2 bug reports further. The mouse "jump" only happens if I play in a borderless window mode in my full monitor resolution. So the mouse seems to reach virtually an edge and then the mouse makes this jump from one place to another. If I switch to fullscreen, the input works well. 

The other issue regarding a slow and stuck mouse, that I've noticed before, seems to be gone completely.

Comment 4 Rainer Finke 2018-11-01 12:19:11 UTC

I've tested this again and there is still an issue with the mouse input in Nexuiz on Plasma Wayland. The mouse starts to jump uncontrollable if I reach in the menu the top or if I move in the game to much into one direction.

Linux 4.9
wayland 1.16
xwayland 1.20.3
libinput 1.12.2
sdl2 2.0.8
Plasma 5.14.2
KDE Frameworks 5.51
Qt 5.12 beta 3

Comment 5 Rainer Finke 2018-11-01 12:24:07 UTC

Should have mentioned this, nexuiz-sdl is still depending on XWayland. I couldn't enforce Wayland with SDL_VIDEODRIVER=wayland.

Comment 6 Patrick Silva 2018-11-02 20:16:17 UTC

I have the same problem on my system with game in fullscreen mode.
Cursor jumps on screen when moved from bottom to top or from right to the left side on the screen. When cursor reaches the top or left edges, it jumps on the screen. Such behavior does not occur on X11.

Operating System: Arch Linux 
KDE Plasma Version: 5.14.2
Qt Version: 5.12.0
KDE Frameworks Version: 5.51.0
Kernel Version: 4.18.16-arch1-1-ARCH

Comment 7 Rainer Finke 2019-05-25 14:41:09 UTC

Still mouse jumps in the main menu of nexus or during gameplay with Plasma 5.16 Beta.

Linux 5.1.4
wayland 1.17
xwayland 1.20.4
libinput 1.13.2
sdl2 2.0.9
Plasma 5.15.90 Wayland
KDE Frameworks 5.58
Qt 5.13 beta

Comment 8 Rainer Finke 2019-10-12 08:19:15 UTC

Still mouse jumps in the main menu of nexus and during gameplay with Plasma 5.17 Beta.

Operating System: Arch Linux 
KDE Plasma Version: 5.16.90
KDE Frameworks Version: 5.62.0
Qt Version: 5.14.0
Kernel Version: 5.3.6-arch1-1-ARCH
OS Type: 64-bit
AMD GPU

Comment 9 David Edmundson 2023-09-06 10:38:21 UTC

This bug was reported against an outdated version of KWin. We have made many changes since the. 
If the issue persists in newer versions can you reopen the bug report updating the version number.