Bug 500424 - Pen input doesn't work as intended on drawing tablet when the screen has scaling set above 100%
Summary: Pen input doesn't work as intended on drawing tablet when the screen has scal...
Status: REPORTED
Alias: None
Product: kwin
Classification: Plasma
Component: input (show other bugs)
Version: 6.3.0
Platform: openSUSE Linux
: NOR normal
Target Milestone: ---
Assignee: KWin default assignee
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2025-02-19 16:00 UTC by Azarilh
Modified: 2025-03-09 19:18 UTC (History)
3 users (show)

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Description Azarilh 2025-02-19 16:00:32 UTC
SUMMARY
Drawing tablets are not very usable on KDE Plasma. I don't know if this is Kscreen or Plasmashell or Wayland, please move it where it needs to go.


STEPS TO REPRODUCE
1. Go to screen settings
2. Increase the scaling of the drawing tablet screen ( i set it to 125% ).
3. Restart

OBSERVED RESULT
The cursor is not alligned with the pen!


EXPECTED RESULT
It should be alligned!


SOFTWARE/OS VERSIONS
Operating System: openSUSE Tumbleweed 20250217
KDE Plasma Version: 6.3.0
KDE Frameworks Version: 6.11.0
Qt Version: 6.8.2
Kernel Version: 6.13.2-1-default (64-bit)
Graphics Platform: Wayland
Processors: 16 × AMD Ryzen 7 7700 8-Core Processor
Memory: 30.5 GiB of RAM
Graphics Processor 1: AMD Radeon RX 7900 GRE
Graphics Processor 2: AMD Radeon Graphics
Manufacturer: ASUS


ADDITIONAL INFORMATION
It's been like this for a long time. It makes scaling useless...
My drawing tablet is a XP-pen Artist 13.3 Pro
Comment 1 Vlad Zahorodnii 2025-02-19 19:58:01 UTC
Do you have any custom settings in drawing tablet system settings? I cannot reproduce the issue on my machine with 140% scaling factor
Comment 2 Azarilh 2025-02-19 21:15:39 UTC
(In reply to Vlad Zahorodnii from comment #1)
> Do you have any custom settings in drawing tablet system settings? I cannot
> reproduce the issue on my machine with 140% scaling factor

Did you reboot your system?

I tried to change drawing table settings but nothing fixes it. The only thing that seem to temp fix it is to change back to 100% scaling, then increase it again. Then it breaks again once i reboot. But it doesn't fix it properly, the cursor is a bit offset so i fix it from the drawing tablet settings ( this is something i've noticed only today, so not sure how it works exactly yet ). I've noticed that it says 1536x864 inside the mapped area box, even tho in the screen settings it states 1920x1080. See screenshot: https://u.cubeupload.com/Azarilh/usdfgh.jpg
Comment 3 Vlad Zahorodnii 2025-02-19 23:15:13 UTC
> Did you reboot your system?

I started computer already at that scale.
Comment 4 Vlad Zahorodnii 2025-02-19 23:16:13 UTC
> I've noticed that it says 1536x864

It's the logical size
Comment 5 Vlad Zahorodnii 2025-02-19 23:21:35 UTC
I've tried map to portion as well. Without being able to reproduce the issue, I'm afraid the bug report is not really actionable
Comment 6 Joshua Goins 2025-02-20 13:48:57 UTC
(In reply to Azarilh from comment #2)
> I've noticed that it says 1536x864 inside the mapped
> area box, even tho in the screen settings it states 1920x1080. See
> screenshot: https://u.cubeupload.com/Azarilh/usdfgh.jpg

The resolution text being different is an unrelated technical issue that shouldn't cause any problems. Relatedly, the mapping setting is stored in relative values (e.g. if you set it to half of your screen, it records "50%" - not "500px".) It wouldn't cause the cursor to be misaligned anyway.
Comment 7 Azarilh 2025-02-20 20:09:14 UTC
(In reply to Vlad Zahorodnii from comment #5)
> I've tried map to portion as well. Without being able to reproduce the
> issue, I'm afraid the bug report is not really actionable

Seems like reducing the area under "Map to Portion" down to 1379x864 fixed my issue even after a reboot. This was not necessary to do without scaling, but at least it works now. I'll update this issue if i find more information that can help.

I am not sure what could be different between our systems that makes it act differently, perhaps display brands. Would prolly need somebody else to report the same issue to figure it out.
Comment 8 Nate Graham 2025-02-26 17:59:45 UTC Comment hidden (spam)
Comment 9 Azarilh 2025-02-26 18:01:31 UTC Comment hidden (spam)
Comment 10 Nate Graham 2025-02-26 18:07:02 UTC Comment hidden (spam)
Comment 11 Azarilh 2025-02-26 18:10:29 UTC Comment hidden (spam)
Comment 12 Nate Graham 2025-02-26 18:14:02 UTC Comment hidden (spam)
Comment 13 Azarilh 2025-03-09 18:21:46 UTC
It got worse for some reason. Now even with the settings that appeared to work for some days, don't work anymore.
I recorded a video that shows the problem. Sorry for the bad focus of the video.
https://www.youtube.com/watch?v=iKW_21ZPGUw
No matter what i choose, even resizing the area, doesn't fix the issue, at most it becomes worse. Even after removing the scaling on the tablet, and rebooted, it still wasn't working...

I just tried the calibration and it won't register when i touch on the bottom circles.
Comment 14 Azarilh 2025-03-09 19:18:57 UTC
Well, installing the official XP-Pen driver made it work even better than before. Their drivers used to only work on X11, but apparently now they work on Wayland.