Bug 319444

Summary:	Brush rotation modifier make brush border pixelated with jagged borders (aliased).
Product:	[Applications] krita	Reporter:	vanyossi <ghevan>
Component:	Brush engines	Assignee:	Krita Bugs <krita-bugs-null>
Status:	RESOLVED FIXED
Severity:	normal	CC:	halla
Priority:	NOR
Version:	git master (please specify the git hash!)
Target Milestone:	---
Platform:	Other
OS:	Linux
Latest Commit:	http://commits.kde.org/calligra/4fc52ba7e25b85d01daea4ae9a17f4078df804a9	Version Fixed In:
Sentry Crash Report:
Attachments:	Rotation aliasing.

Description vanyossi 2013-05-07 02:18:59 UTC

If using a predefined brush, grb, abr, svg. setting the brush modifier "rotation" will make the rendering extremely pixelated.

Reproducible: Always

Steps to Reproduce:
1. Select a predefined brush tip
2. Set Rotation modifier to any curve (pressure, fuzzy)
3. Set spacing to a high separation to appreciate it better.
Actual Results:  
Printed brush tip becomes jaggy and pixelated.

Expected Results:  
Printed brush tip keeps the border relatively smooth.

Deffect is visible at any brush size, it affects specially in long spacing shapes. For example, using a "foliage" brush we set a rotation to random to help hide the pattern. And a high spacing to actually see the foliage.

Comment 1 vanyossi 2013-05-07 02:21:02 UTC

Created attachment 79748 [details]
Rotation aliasing.

Added a png file with the rotation aliased defect. A bit exaggerated due to small image size, but still visible at big sizes.

Comment 2 Halla Rempt 2013-05-18 08:48:20 UTC

Ack. I can reproduce the issue, too.

Comment 3 Halla Rempt 2013-05-18 08:50:58 UTC

Git commit 64587cce112743eb5fcacf2d65c227c7c407ca81 by Boudewijn Rempt.
Committed on 18/05/2013 at 10:49.
Pushed by rempt into branch 'master'.

Use Qt::SmoothTransformation when rotating

M  +1    -1    krita/plugins/paintops/libbrush/kis_brush.cpp
M  +1    -1    krita/plugins/paintops/libbrush/kis_qimage_mask.cpp

http://commits.kde.org/calligra/64587cce112743eb5fcacf2d65c227c7c407ca81

Comment 4 vanyossi 2013-05-21 01:54:57 UTC

Working good. Thanks for the quick fix boud! :]

Comment 5 Halla Rempt 2013-05-31 08:35:03 UTC

Git commit 4fc52ba7e25b85d01daea4ae9a17f4078df804a9 by Boudewijn Rempt.
Committed on 18/05/2013 at 10:49.
Pushed by rempt into branch 'calligra/2.7'.

Use Qt::SmoothTransformation when rotating

M  +1    -1    krita/plugins/paintops/libbrush/kis_brush.cpp
M  +1    -1    krita/plugins/paintops/libbrush/kis_qimage_mask.cpp

http://commits.kde.org/calligra/4fc52ba7e25b85d01daea4ae9a17f4078df804a9