Bug 407272 - Color Smudge Engine Missing Subpixel Detection
Summary: Color Smudge Engine Missing Subpixel Detection
Status: CONFIRMED
Alias: None
Product: krita
Classification: Applications
Component: Brush engines (show other bugs)
Version: unspecified
Platform: unspecified All
: NOR normal
Target Milestone: ---
Assignee: Krita Bugs
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2019-05-06 17:18 UTC by til.schmitter
Modified: 2019-05-07 07:48 UTC (History)
2 users (show)

See Also:
Latest Commit:
Version Fixed In:
Sentry Crash Report:


Attachments
Comparison Quick Brush vs. Color Smudge (190.88 KB, image/png)
2019-05-06 17:18 UTC, til.schmitter
Details

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Description til.schmitter 2019-05-06 17:18:05 UTC
Created attachment 119873 [details]
Comparison Quick Brush vs. Color Smudge

SUMMARY
I noticed my paintings always look a bit jagged. This shouldn't be a problem though, even if i do paint at a lower resolution. i then investigated further and noticed the Color Smudge Engine has no subpixel pointer detection like the Quick Brush Engine for example.

STEPS TO REPRODUCE
1. Pick any Color Smudge Engine Brush with a size of about 1 px.
2. Zoom in to about 800%
3. Use the line tool to draw a not completely straight line.

OBSERVED RESULT
There is no antialiasing before the line jumps to the next pixel, no matter the precision in the brush settings.

EXPECTED RESULT
Any kind of antialiasing

SOFTWARE/OS VERSIONS
Windows 10: Yes
macOS: Not verified, likely a problem too.
Linux (Ubuntu): Yes
Krita Version: 4.2.0 pre-alpha, though probably not a new thing.
Comment 1 wolthera 2019-05-06 17:33:41 UTC
Subpixel is turned off for the smearing mode only(where it can create serious artifacts), it works with the dulling mode.

Here's the line of code:

https://invent.kde.org/kde/krita/blob/master/plugins/paintops/colorsmudge/kis_colorsmudgeop.cpp#L167
Comment 2 til.schmitter 2019-05-06 20:49:19 UTC
thanks for the quick response! do you know if it's being worked on? but i guess it's good to at least know it's supposed to be like that...
Comment 3 Halla Rempt 2019-05-07 07:48:39 UTC
No, it's not something we're working on. Like Wolthera said, if we'd enable it would create really weird artefacts.