Bug 417342 - Horizontal and vertical lines with fractional HiDPI scaling (Gwenview)
Summary: Horizontal and vertical lines with fractional HiDPI scaling (Gwenview)
Status: RESOLVED FIXED
Alias: None
Product: gwenview
Classification: Applications
Component: general (show other bugs)
Version: 19.12.2
Platform: Neon Linux
: NOR normal
Target Milestone: ---
Assignee: Gwenview Bugs
URL:
Keywords:
: 432553 (view as bug list)
Depends on:
Blocks:
 
Reported: 2020-02-09 15:14 UTC by michel.mastriani
Modified: 2021-03-19 17:29 UTC (History)
4 users (show)

See Also:
Latest Commit:
Version Fixed In: 20.12.2


Attachments
Gwenview with lines when fractional HiDPI scaling is enabled (1.60 MB, image/jpeg)
2020-02-09 15:14 UTC, michel.mastriani
Details

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Description michel.mastriani 2020-02-09 15:14:21 UTC
Created attachment 125785 [details]
Gwenview with lines when fractional HiDPI scaling is enabled

SUMMARY
My Gwenview is drawing lines on the image when fractional HiDPI scaling is enabled. Not exclusive to the mentioned version, it's happening a long time ago.


STEPS TO REPRODUCE
1. Change global scale by 1.4 (I think other value results the same problem, but I use 1.4)
2. Open the image: https://drive.google.com/open?id=1_5-aNgr2bw88vipVer2c8szhhhonuJ-B (doesn't happen with all images, so open that one)
3. press CONTROL+ to add zoom so that the user can drag the image up-down and left-right
4. drag the image up-down and left-right


OBSERVED RESULT
Horizontal and vertical lines on the image as attached file as attached file

EXPECTED RESULT
Horizontal and vertical lines on the image as attached file as attached file

SOFTWARE/OS VERSIONS
Linux/KDE Plasma: KDE Neon
KDE Plasma Version: 5.17.5
KDE Frameworks Version: 5.66.0
Qt Version: 5.13.2

ADDITIONAL INFORMATION
Comment 1 Patrick Silva 2020-02-18 19:05:52 UTC
Gwenview 19.12.2 sometimes shows a horizontal line if I set display scale to 125% on system.

Operating System: Arch Linux 
KDE Plasma Version: 5.18.0
KDE Frameworks Version: 5.67.0
Qt Version: 5.14.1
Comment 2 Bug Janitor Service 2021-01-29 22:18:28 UTC
A possibly relevant merge request was started @ https://invent.kde.org/graphics/gwenview/-/merge_requests/35
Comment 3 Vlad Zahorodnii 2021-02-01 18:36:28 UTC
Git commit 955df5addac77b49c8349e6477806dbf27bde238 by Vlad Zahorodnii.
Committed on 01/02/2021 at 18:35.
Pushed by vladz into branch 'release/20.12'.

Fix visual artifacts when panning zoomed in image on HiDPI

The size of the viewport rectangle needs to be in the device-independent
pixels; otherwise there will be visual artifacts when panning a zoomed in
translucent image.
Related: bug 428397, bug 414776

M  +6    -6    lib/documentview/rasterimageview.cpp

https://invent.kde.org/graphics/gwenview/commit/955df5addac77b49c8349e6477806dbf27bde238
Comment 4 Nate Graham 2021-02-06 21:57:10 UTC
*** Bug 432553 has been marked as a duplicate of this bug. ***
Comment 5 Nate Graham 2021-03-19 16:46:46 UTC
*** Bug 434596 has been marked as a duplicate of this bug. ***