Bug 472218

Summary:	Freehand annotation jagged / frayed lines with drawing tablet (Windows)
Product:	[Applications] okular	Reporter:	Ant Palmer <antpalmer.palmink>
Component:	general	Assignee:	Okular developers <okular-devel>
Status:	REPORTED ---
Severity:	normal	CC:	felipedilho, j3.soon777, jasonindestructible
Priority:	NOR
Version First Reported In:	23.08.1
Target Milestone:	---
Platform:	Microsoft Windows
OS:	Microsoft Windows
Latest Commit:		Version Fixed In:
Sentry Crash Report:
Attachments:	image of jagged lines

Description Ant Palmer 2023-07-13 13:06:30 UTC

Created attachment 160264 [details]
image of jagged lines

SUMMARY
***
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***

The longer a line is held down using a drawing tablet, the more frayed the line seems to become. Using a Huion Inspiroy H610PROV2. Works fine on Gimp / Xournal++.

STEPS TO REPRODUCE
1. Open any pdf on okular (on windows)
2.  Draw a line using the freehand line tool (alt + 8)


OBSERVED RESULT
See image

EXPECTED RESULT
smooth lines and circles

SOFTWARE/OS VERSIONS
Windows: Windows 11 22H2, Build 22621.1992
KDE Plasma Version: n/a (?)
KDE Frameworks Version: n/a (?)
Qt Version: unsure (where do I find this)

ADDITIONAL INFORMATION

Comment 1 Johnson Sun 2023-08-12 07:49:03 UTC

I can reproduce this issue in both Windows 10 and Windows 11 using a Wacom Intuos tablet (with the latest driver). Interestingly, the same issue does not exist when using the Linux (Ubuntu) version of Okular.

I suspect this is a platform-specific issue.

Related:
- https://bugs.kde.org/show_bug.cgi?id=410723
- https://stackoverflow.com/q/31172532

Comment 2 Jason 2023-09-22 14:30:40 UTC

I can reproduce this issue as well. I use Windows 11 on a Samsung Galaxy Book Pro 360 with a Samsung Pen. 
Samsung uses Wacom tech and drivers, so the nature of the issue is similar to those with drawing tablets.

Comment 3 Jason 2023-09-22 14:51:49 UTC

Related: Bug 437401

Comment 4 Felipe Dilho Alves 2024-07-15 10:35:56 UTC

I am also experiencing this same issue with my HP tablet 11 running Windows 11 with a HP active pen (I don't think it uses Wacom technology), also the lines take some processing before they do appear, there is probably some problem with the input filtering that instead of ignoring the majority of the signals to produce a smooth line with a small amount of points, the program seems to be including all the input data with its respective noise, which is generating this spiked/jagged effect on the lines.