Bug 414259

Summary:	Inconsistent scaling with vertically tall, thin predefined brush tips
Product:	[Applications] krita	Reporter:	M <manuel.snudl.zeidler>
Component:	Usability	Assignee:	Krita Bugs <krita-bugs-null>
Status:	CONFIRMED ---
Severity:	normal	CC:	ahab.greybeard
Priority:	NOR
Version First Reported In:	nightly build (please specify the git hash!)
Target Milestone:	---
Platform:	Other
OS:	Linux
Latest Commit:		Version Fixed/Implemented In:
Sentry Crash Report:
Attachments:	Tall brush tip for testing.

Description M 2019-11-18 09:34:17 UTC

Created attachment 123982 [details]
Tall brush tip for testing.

SUMMARY
Using a predefined brush tip that is vertically long but horizontally slim will cause a way huger brush size than the set pixel value. On the other hand, horizontally wide and vertically short ones scale correctly. Auto tips with a very low ratio value also behave correctly.

STEPS TO REPRODUCE
1. Create a tall bitmap brush tip or use the attached example.
2. Compare the resulting size of the brush outline and stroke with other brush tips.

OBSERVED RESULT
Giant brush size, depending on tip's aspect ratio.

EXPECTED RESULT
Same scaling as the well behaved tips.

SOFTWARE/OS VERSIONS
Master (git 938bf9e).

Comment 1 Ahab Greybeard 2019-11-21 15:24:37 UTC

I can confrim this for the 4.2.8 beta 1 appimage.

For the example brush tip given, which has an aspect ratio of 512/16 = 32, the brush is 32 times higher that the set size.  If this is changed to a 256/16 = 16 aspect ratio gbr file then it is 16 times higher.
Placing the brush image on a 512 x 512 white background gives a brush that is the same height as the set size.
Placing it on a 256 x 512 white background gives a brush that is 2 times higher than the set size.