Bug 409401

Summary: anti-aliasing does not work in kolourpaint
Product: [Applications] kolourpaint Reporter: grechin.sergey
Component: generalAssignee: kolourpaint-support
Status: REOPENED ---    
Severity: normal CC: martin, nate, nortexoid
Priority: NOR    
Version First Reported In: 18.04   
Target Milestone: ---   
Platform: Other   
OS: Linux   
Latest Commit: Version Fixed/Implemented In:
Sentry Crash Report:

Description grechin.sergey 2019-07-02 08:58:31 UTC
SUMMARY

antialiasing doesn't work.
No matter if i choose it to be on or off in settings>draw anti-aliased
it always draws without anti-aliasing.

This makes it kind of unusable for my purposes as a simple graphical tablet supporting app for notes.

http://i.imgur.com/DJGXaIy.png

STEPS TO REPRODUCE
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OBSERVED RESULT


EXPECTED RESULT


SOFTWARE/OS VERSIONS
Windows: 
macOS: 
Linux/KDE Plasma: 
(available in About System)
KDE Plasma Version: 
KDE Frameworks Version: 
Qt Version: 

ADDITIONAL INFORMATION
Comment 1 Martin Koller 2019-07-15 09:30:36 UTC
Anti-Alias is only used for polygon, rectangle, etc. but not for
freehand lines (Pen).
I mentioned the reason in the comment in the sources:
// never use AA - it does not look good for the usually very short lines
Comment 2 Nate Graham 2019-07-15 14:11:19 UTC
Hmm, that's not my expectation as a user. I think anti-aliased lines always look better than aliased ones. If you feel that there are use cases where anti-aliasing looks worse, could we try to have the code intelligently handle those cases, or making it configurable?
Comment 3 Michael D 2020-11-11 21:37:21 UTC
Anti-aliasing always looks better when I compare what is produced in kolourpaint and what is produced in xournal++ (with xournal++ looking much better). I think it is worth reconsidering or having an option to enable/disable for freehand lines.
Comment 4 Nate Graham 2020-11-11 21:51:10 UTC
Agreed. The pixelated lines just don't look good.