Bug 429776

Summary: selection tool subtracts instead of adds and vice versa
Product: [Applications] krita Reporter: tschoardschie <florian.hilbrand>
Component: Tools/SelectionAssignee: Krita Bugs <krita-bugs-null>
Status: RESOLVED INTENTIONAL    
Severity: normal CC: ahab.greybeard, griffinvalley
Priority: NOR    
Version First Reported In: 4.4.1   
Target Milestone: ---   
Platform: Compiled Sources   
OS: All   
Latest Commit: Version Fixed/Implemented In:
Sentry Crash Report:
Attachments: you see a little square that is missing in the subtract selection mask (=red), and when i want to subtract it, it randomly fills the whole mask, except the part i want to subtract

Description tschoardschie 2020-11-28 18:36:46 UTC
Created attachment 133711 [details]
you see a little square that is missing in the subtract selection mask (=red), and when i want to subtract it, it randomly fills the whole mask, except the part i want to subtract

SUMMARY


STEPS TO REPRODUCE
1. on new layer select rectangular selection tool
2. select subtract 
3. make pattern you want to be cutout from layer below

OBSERVED RESULT
sometimes it adds instead of subtracting and vice versa

EXPECTED RESULT
not doing that?

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

ADDITIONAL INFORMATION
Comment 1 Ahab Greybeard 2020-11-30 11:41:43 UTC
I believe that the operation of the selection tools in Subtract mode are logically/arithmetically correct but it can be confusing.
Also, there's a subtle difference if you use the global selection mask instead of relying on the 'marching ants' outlines.

Please go to https://krita-artists.org/ and start a topic there in the Support and Advice: General Questions category.
That forum is a very suitable place for discussion and posting many illustrative images as part of the discussion.
Comment 2 wolthera 2021-09-08 08:31:11 UTC
Yes, this seems to be a confusion about what the mask actually does. It represents the unselected areas with overlay, and selected areas without an overlay, so subtract will add overlay. This is how it works in all programs with such a mask, so I will close this bug.