Bug 484889

Summary: Artifacts with rectangular grid
Product: [Applications] krita Reporter: grum999
Component: GeneralAssignee: Krita Bugs <krita-bugs-null>
Status: RESOLVED FIXED    
Severity: normal    
Priority: NOR    
Version: 5.2.2   
Target Milestone: ---   
Platform: Other   
OS: Linux   
Latest Commit: https://invent.kde.org/graphics/krita/-/commit/fca99898de4472ca2bd41498f568072fb1ef9349 Version Fixed In:
Sentry Crash Report:
Attachments: Example of bug

Description grum999 2024-04-01 20:15:32 UTC 
Created attachment 168036 [details]
Example of bug

SUMMARY
Following this KA post:
https://krita-artists.org/t/grids-guides-improvements/85979/16?u=grum999

We can see glitches/artifacts on rectangular grid when brush is moved over canvas.
- Occurs only if canvas acceleration is ON
- And only impact subdivision lines style is set to “Lines” (“Dashed”, “Dot” works)

STEPS TO REPRODUCE
1. Create a new document
2. Select any brush (basic-1)
3. Setup a rectangular grid with subdivision lines as "Solid"
4. Move the brush over the grid 

OBSERVED RESULT
Artifacts & Glitches on the grid

EXPECTED RESULT
Grid is properly rendered

ADDITIONAL INFORMATION
It works properly in Krita 5.1.3 and bug start from Krita 5.1.5
Comment 1 Dmitry Kazakov 2024-04-04 12:34:34 UTC 
Git commit 5d5719abba4717019d2ed6491431672b108a0d98 by Dmitry Kazakov, on behalf of Grum 999.
Committed on 04/04/2024 at 12:34.
Pushed by dkazakov into branch 'master'.

Fix grids glitches when subdivision style is solid

Bug has been introduced with commit 764719791a4ce6887aedc9d92777f3c4a03198c6 (to fix bug 461912)

From Qt's documentation, setDashOffset() method implicitly converts the style of the pen to Qt::CustomDashLine.
When current line style is solid, it seems the custom dash line is not soid anymore and this generate glitches.

To avoid the problem, need to to check if style is solid or not before updating dash offset (update only if not solid).

In addition, the original commit only 'fixed' dash offset problem for subdivision but not for main grid division; this commit fix both (main & subdivision) grids lines.

M  +13   -3    libs/ui/canvas/kis_grid_decoration.cpp

https://invent.kde.org/graphics/krita/-/commit/5d5719abba4717019d2ed6491431672b108a0d98
Comment 2 Dmitry Kazakov 2024-04-04 12:34:56 UTC 
Git commit fca99898de4472ca2bd41498f568072fb1ef9349 by Dmitry Kazakov, on behalf of Grum 999.
Committed on 04/04/2024 at 12:34.
Pushed by dkazakov into branch 'krita/5.2'.

Fix grids glitches when subdivision style is solid

Bug has been introduced with commit 764719791a4ce6887aedc9d92777f3c4a03198c6 (to fix bug 461912)

From Qt's documentation, setDashOffset() method implicitly converts the style of the pen to Qt::CustomDashLine.
When current line style is solid, it seems the custom dash line is not soid anymore and this generate glitches.

To avoid the problem, need to to check if style is solid or not before updating dash offset (update only if not solid).

In addition, the original commit only 'fixed' dash offset problem for subdivision but not for main grid division; this commit fix both (main & subdivision) grids lines.


(cherry picked from commit 5d5719abba4717019d2ed6491431672b108a0d98)

M  +13   -3    libs/ui/canvas/kis_grid_decoration.cpp

https://invent.kde.org/graphics/krita/-/commit/fca99898de4472ca2bd41498f568072fb1ef9349