Created attachment 59294 [details]
Picture with marked corruption after paning around
Version: 2.6 (using KDE 4.6.2)
Open any image with vertical lines. Zoom in to non x00% (i.e. 233%). Pan around image and see how stright vertical lines get corrupted.
Sample image: http://upload.wikimedia.org/wikipedia/commons/5/50/Signal_Sampling.png
Created attachment 73693 [details]
zoomed image corruption after panning
I can confirm it.
Using Gwenview 2.9.0 with KDE 4.9.00 on openSUSE 12.2 i586.
It still happens on KDE 4.10.1. It's very annoying bug :(
*** Bug 324559 has been marked as a duplicate of this bug. ***
*** Bug 330332 has been marked as a duplicate of this bug. ***
*** Bug 333165 has been marked as a duplicate of this bug. ***
*** Bug 344122 has been marked as a duplicate of this bug. ***
*** Bug 427369 has been marked as a duplicate of this bug. ***
KDE Frameworks 5.75.0
Qt 5.15.1 (built against 5.15.1)
Disabling / switching animations to Software / OpenGL does not fix it
*** Bug 429754 has been marked as a duplicate of this bug. ***
KDE Frameworks 5.77.0
Qt 5.15.2 (built against 5.15.2)
I can confirm this bug but only when opening images with alpha transparency, if I convert the image to an image without alpha channel this problems disappears.
A possibly relevant merge request was started @ https://invent.kde.org/graphics/gwenview/-/merge_requests/66
Git commit 726c52998c50252fe2ce74c1ba63e52c3355a18a by Nate Graham, on behalf of Arjen Hiemstra.
Committed on 11/05/2021 at 15:24.
Pushed by ngraham into branch 'master'.
Use a simple QGraphicsItem subclass for drawing raster images
RasterImageView was using a custom implementation that would use two
QPixmaps to do double buffered rendering. However, since Qt already
renders things double buffered, we are doing duplicate work. So drop
that and use a simple QGraphicsItem subclass that paints the loaded
image directly. This simplifies things a lot and removes a fair amount
of difficult to follow custom code.
M +146 -248 lib/documentview/rasterimageview.cpp
M +2 -4 lib/documentview/rasterimageview.h