Created attachment 72894 [details]
Screenshot showing the graphical artifacts

I'm wondering whether this is related to bug #304404. In both cases I'm not 
able to reproduce and I wouldn't be surprised if there is a shared reason for 
both issues.

I updated to 4.9.1 (opensuse 12.2 packages) and I still experience this problem.
I suggest a different test to reproduce (with a fresh kwin --replace):
1) Move the mouse cursor e.g. to center, center of the screen.
2) Use the zoom in effect (whole screen zoomed)
3) Zoom out again to normal size
4) Move the mouse cursor e.g. to near the lower left of the screen
5) Activate Track Mouse effect

The two rings now move eccentrically, with part of their orbit lying outside of the bounding box. Now when you move the mouse cursor while the effect is active, the parts of the rings which are outside of the bounding box can generate the artifacts (i.e. you can paint your screen with them).

The most interesting thing about this is that the rings are orbitting almost centered when you move to the position near center, center where you used the zoom desktop effect initially (Step 1). The farther you move away from this position, the more eccentric the movement of the rings becomes and vice versa. You repeat the whole procedure starting with the mouse cursor at different positions of the screen. These positions will then be the ones in whose proximitiy the Track Mouse effect will work as expected (i.e. centric movement regardless of the mouse cursor's position).

please post the output of "qdbus org.kde.kwin /KWin supportInformation" and check whether you can reproduce this issue with the XRender compositor and by swapping (turning off) the "OpenGL 2 shader" checkbox (both in 3rd tab of "kcmshell4 kwincompositing")

Also check whether the usage of the blur effect has impact on this.

What you describe is a "glTranslate" (usage) error.
How much is the deflection? (like "One px or ten")

The culprit seems to be the OpenGL 2 Shaders. I cannot reproduce the problem with them turned off. It is, however independent of the blur effect's state (happens when it's on and off). With XRender, it does not occur either. The deflection can be immense (it grows the farther the cursor is away from the original zooming position).

output of qdbus org.kde.kwin /KWin supportInformation:
KWin Support Information:
The following information should be used when requesting support on e.g. http://forum.kde.org.
It provides information about the currently running instance, which options are used,
what OpenGL driver and which effects are running.
Please post the information provided underneath this introductory text to a paste bin service
like http://paste.kde.org instead of pasting into support threads.

==========================

Options
=======
focusPolicy: 0
nextFocusPrefersMouse: false
clickRaise: true
autoRaise: false
autoRaiseInterval: 0
delayFocusInterval: 0
shadeHover: false
shadeHoverInterval: 250
tiling: false
tilingLayout: 0
tilingRaisePolicy: 0
separateScreenFocus: false
activeMouseScreen: false
placement: 4
focusPolicyIsReasonable: true
borderSnapZone: 10
windowSnapZone: 10
centerSnapZone: 0
snapOnlyWhenOverlapping: false
showDesktopIsMinimizeAll: false
rollOverDesktops: true
focusStealingPreventionLevel: 1
legacyFullscreenSupport: false
operationTitlebarDblClick: 
commandActiveTitlebar1: 0
commandActiveTitlebar2: 30
commandActiveTitlebar3: 2
commandInactiveTitlebar1: 4
commandInactiveTitlebar2: 30
commandInactiveTitlebar3: 2
commandWindow1: 7
commandWindow2: 8
commandWindow3: 8
commandWindowWheel: 31
commandAll1: 10
commandAll2: 3
commandAll3: 14
keyCmdAllModKey: 16777251
showGeometryTip: false
electricBorders: false
electricBorderDelay: 150
electricBorderCooldown: 350
electricBorderPushbackPixels: 1
electricBorderMaximize: true
electricBorderTiling: true
borderlessMaximizedWindows: false
killPingTimeout: 5000
hideUtilityWindowsForInactive: true
inactiveTabsSkipTaskbar: false
autogroupSimilarWindows: false
autogroupInForeground: true
compositingMode: 1
useCompositing: true
compositingInitialized: true
hiddenPreviews: 0
unredirectFullscreen: false
glSmoothScale: 0
glVSync: true
xrenderSmoothScale: false
maxFpsInterval: 17
refreshRate: 0
vBlankTime: 6144
glDirect: true
glStrictBinding: false
glStrictBindingFollowsDriver: true

Compositing
===========
Qt Graphics System: native
Compositing is active
Compositing Type: OpenGL
OpenGL vendor string: NVIDIA Corporation
OpenGL renderer string: GeForce GT 525M/PCIe/SSE2
OpenGL version string: 4.2.0 NVIDIA 295.59
Driver: NVIDIA
Driver version: 295.59
GPU class: GF100
OpenGL version: 4.2
X server version: 1.12.3
Linux kernel version: 3.5.3
Direct rendering: yes
Requires strict binding: no
GLSL shaders:  yes
Texture NPOT support:  yes
OpenGL 2 Shaders are used

Loaded Effects:
---------------
kwin4_effect_zoom
kwin4_effect_trackmouse
kwin4_effect_invert
kwin4_effect_login
kwin4_effect_slidingpopups
kwin4_effect_translucency
kwin4_effect_screenshot
kwin4_effect_slide
kwin4_effect_desktopgrid
kwin4_effect_flipswitch
kwin4_effect_fade
kwin4_effect_dialogparent
kwin4_effect_highlightwindow
kwin4_effect_presentwindows
kwin4_effect_blur
kwin4_effect_logout
kwin4_effect_dashboard
kwin4_effect_outline
kwin4_effect_startupfeedback

Currently Active Effects:
-------------------------
kwin4_effect_translucency
kwin4_effect_blur

Effect Settings:
----------------
kwin4_effect_zoom:
zoomFactor: 2
mousePointer: 0
mouseTracking: 0
enableFocusTracking: true
followFocus: true
focusDelay: 350
moveFactor: 20
targetZoom: 1

kwin4_effect_trackmouse:
modifiers: 335544320
mousePolling: true

kwin4_effect_invert:

kwin4_effect_login:
fadeToBlack: false

kwin4_effect_slidingpopups:
fadeInTime: 250
fadeOutTime: 250

kwin4_effect_translucency:
decoration: 1
moveResize: 0.8
dialogs: 1
inactive: 1
comboboxPopups: 1
menus: 1
individualMenuConfig: false
dropDownMenus: 1
popupMenus: 1
tornOffMenus: 1
moveResizeDuration: 800
activeInactiveDuration: 800

kwin4_effect_screenshot:

kwin4_effect_slide:

kwin4_effect_desktopgrid:
zoomDuration: 300
border: 10
desktopNameAlignment: 0
layoutMode: 0
customLayoutRows: 2
usePresentWindows: true

kwin4_effect_flipswitch:
tabBox: false
tabBoxAlternative: false
duration: 200
angle: 30
xPosition: 0.330000013113022
yPosition: 1
windowTitle: true

kwin4_effect_fade:

kwin4_effect_dialogparent:
changeTime: 300

kwin4_effect_highlightwindow:

kwin4_effect_presentwindows:
layoutMode: 0
showCaptions: true
showIcons: true
doNotCloseWindows: false
ignoreMinimized: false
accuracy: 20
fillGaps: true
fadeDuration: 150
showPanel: false
leftButtonWindow: 1
rightButtonWindow: 2
middleButtonWindow: 0
leftButtonDesktop: 2
middleButtonDesktop: 0
rightButtonDesktop: 0
dragToClose: false

kwin4_effect_blur:
blurRadius: 12
cacheTexture: true

kwin4_effect_logout:
useBlur: true

kwin4_effect_dashboard:
brightness: 0.5
saturation: 0.5
blur: false

kwin4_effect_outline:

kwin4_effect_startupfeedback:

does it remain when deactivating Translucency AND Blurring?

Yes. I deactivated translucency and blurring now, and I can still reproduce it. (I also tried updating the proprietary nvidia driver to version 304.43, but this does not change anything)

Can you reproduce it at all when disabling the zoom effect entirely?

I cannot reproduce it ad hoc as I would not know how. But I deactivated zoom now and I'll be watching if I encounter the problem again.

Can you confirm that it's related to the zoom effect and glsl?

What I observed is the following:
I can trigger it only the way I described it in comment #3, i.e. after using the zoom effect.
I cannot trigger the behavior with XRender, nor when only OpenGL 1 shaders (legacy code path) are used.
So it happens only when OpenGL 2.0 shaders used.

When I trigger the show mouse effect while zoomed (whole desktop), the show mouse effect is rendered correctly. But when I zoom out and use 'show mouse cursor', the farther I move the cursor away from the position I did the zooming-out from, the more the rotational center in each of the two graphical elements of the show mouse effect gets moved away from its correct rotation center (which would be in the center of the arcs). This results in the two arcs rotating grotesquely around the mouse arrow instead of the concentric motion one would expect. When the mouse cursor is moved in the former state, the pixels outside of the clipping rectangle do not get erased and stay on the screen until the relevant portion is repainted (i.e. scrolling the underlying browser window).

It would be extra great if you could possibly test the patch.
https://git.reviewboard.kde.org/r/108172/

The patch does not seem to cure the issue, but maybe I did something wrong. What I did is:
I downloaded the latest tarball with:
[code]wget -c http://anongit.kde.org/kde-workspace/kde-workspace-latest.tar.gz[/code]
untarred, changed to the directory and did:
[code]patch -p 1 < 0001-inject-synthetic-render-pass-with-1.0-zooming.patch[/code]
then I built with:
[code]mkdir build
cd build
cmake .. -DCMAKE_INSTALL_PREFIX=/usr/local -DCMAKE_BUILD_TYPE=debugfull -DKWIN_BUILD_OXYGEN=OFF -DKDE4_BUILD_TESTS=TRUE
cd kwin
make
sudo make install
[/code]
I then created a file with the content:
[code]
#!/bin/bash
export KDEDIR=/usr/local
export KDEDIRS=$KDEDIR #:$KDEDIRS # remove the added $KDEDIRS if you don't want to find your distribution KDE version

# Add the KDE plugins to the Qt plugins path
export QT_PLUGIN_PATH=$KDEDIR/lib/kde4/plugins

# Export the standard paths to include KDE
export PATH=$KDEDIR/bin:$PATH
export LD_LIBRARY_PATH=$KDEDIR/lib:$LD_LIBRARY_PATH

export PKG_CONFIG_PATH=$KDEDIR/lib/pkgconfig:$PKG_CONFIG_PATH
/usr/local/bin/kwin --replace
[/code]
I started this from a console. kwin seemed to be replaced and so I tested whether the artifact still occurs and it does.

So if there's anything wrong with my procedure, could you please help me to get it right?
Thank you!

the important question is, which kwin4_effect_builtins.so got load.
just edit kwin/effects/zoom/zoom.cpp and around line 100 inject

qDebug() << "good, running patched version";


recompile (should run quickly) and restart kwin from konsole.
If you can see that line printed, you're running the patched effect - otherwise not.

I've no experience with running user local KDE versions but you  could also strace kwin and grep for kwin4_effect_builtins to see what's tested and ultimately loaded.

The debug output I inserted as you suggested is shown, so I'm running the compiled version.

:-(

Does the observation of comment #3 still hold?
Would you mind sharing your ~/.kde/share/config/kwinrc
(i reconstructed zoom and trackmouse settings, without success. Yes, nvidia blob as well)

Yes, the observations from comment #3 still hold true. 
I forgot to mention something previously: when I start the custom kwin from my script, I get a crash, but it seems that the custom kwin is started nevertheless (on the console, this error is shown: kwin(2960) KWin::x11ErrorHandler: kwin: X Error ( "error: BadDamage [DAMAGE+0], request: XDamageDestroy[DAMAGE+2], resource: 0x22a" )) and I don't know if it is related anyway.

Maybe you can judgde from the backtrace:

Application: KWin (kwin), signal: Aborted
Using host libthread_db library "/lib64/libthread_db.so.1".
[Current thread is 1 (Thread 0x7ff34747c7c0 (LWP 2836))]

Thread 2 (Thread 0x7ff33a0fd700 (LWP 2866)):
#0  0x00007ff3589478f4 in pthread_cond_wait@@GLIBC_2.3.2 () from /lib64/libpthread.so.0
#1  0x00007ff35a808247 in QTWTF::TCMalloc_PageHeap::scavengerThread (this=0x7ff35ab15640 <QTWTF::pageheap_memory>) at ../3rdparty/javascriptcore/JavaScriptCore/wtf/FastMalloc.cpp:2359
#2  0x00007ff35a808279 in QTWTF::TCMalloc_PageHeap::runScavengerThread (context=<optimized out>) at ../3rdparty/javascriptcore/JavaScriptCore/wtf/FastMalloc.cpp:1464
#3  0x00007ff3577b9734 in ?? () from /usr/lib64/libGL.so.1
#4  0x00007ff358943e0e in start_thread () from /lib64/libpthread.so.0
#5  0x00007ff3568342bd in clone () from /lib64/libc.so.6

Thread 1 (Thread 0x7ff34747c7c0 (LWP 2836)):
[KCrash Handler]
#6  0x00007ff356784d25 in raise () from /lib64/libc.so.6
#7  0x00007ff3567861a8 in abort () from /lib64/libc.so.6
#8  0x00007ff358bcfc14 in qt_message_output(QtMsgType, char const*) () from /usr/lib64/libQtCore.so.4
#9  0x00007ff358bcfdc8 in ?? () from /usr/lib64/libQtCore.so.4
#10 0x00007ff358bcff54 in qFatal(char const*, ...) () from /usr/lib64/libQtCore.so.4
#11 0x00007ff358bcff9a in qt_assert(char const*, char const*, int) () from /usr/lib64/libQtCore.so.4
#12 0x00007ff35e27f3d3 in KWin::Compositor::self () at /home/tom/Downloads/kde/kde-workspace/kwin/composite.h:142
#13 0x00007ff35e301feb in KWin::Toplevel::compositing (this=0x14da0f0) at /home/tom/Downloads/kde/kde-workspace/kwin/composite.cpp:921
#14 0x00007ff35e30296a in KWin::Toplevel::addWorkspaceRepaint (this=0x14da0f0, r2=...) at /home/tom/Downloads/kde/kde-workspace/kwin/composite.cpp:1092
#15 0x00007ff35e280301 in KWin::Client::releaseWindow (this=0x14da0f0, on_shutdown=true) at /home/tom/Downloads/kde/kde-workspace/kwin/client.cpp:269
#16 0x00007ff35e264ecb in KWin::Workspace::~Workspace (this=0x1424b50, __in_chrg=<optimized out>) at /home/tom/Downloads/kde/kde-workspace/kwin/workspace.cpp:516
#17 0x00007ff35e265612 in KWin::Workspace::~Workspace (this=0x1424b50, __in_chrg=<optimized out>) at /home/tom/Downloads/kde/kde-workspace/kwin/workspace.cpp:550
#18 0x00007ff35e2a18c7 in KWin::Application::lostSelection (this=0x7fff9a4fa790) at /home/tom/Downloads/kde/kde-workspace/kwin/main.cpp:353
#19 0x00007ff35e2a2b71 in KWin::Application::qt_static_metacall (_o=0x7fff9a4fa790, _c=QMetaObject::InvokeMetaMethod, _id=0, _a=0x7fff9a4f9df0) at /home/tom/Downloads/kde/kde-workspace/build/kwin/main.moc:51
#20 0x00007ff358ceb0ff in QMetaObject::activate(QObject*, QMetaObject const*, int, void**) () from /usr/lib64/libQtCore.so.4
#21 0x00007ff359a19dd3 in KSelectionOwner::filterEvent (this=0x7fff9a4fa7a8, ev_P=<optimized out>) at /usr/src/debug/kdelibs-4.9.5/kdeui/util/kmanagerselection.cpp:224
#22 0x00007ff3599b937e in publicx11Event (e=<optimized out>, this=<optimized out>) at /usr/src/debug/kdelibs-4.9.5/kdeui/kernel/kapplication.cpp:918
#23 KApplication::x11EventFilter (this=0xb14, _event=0x7fff9a4fa490) at /usr/src/debug/kdelibs-4.9.5/kdeui/kernel/kapplication.cpp:930
#24 0x00007ff35e2a1954 in KWin::Application::x11EventFilter (this=0x7fff9a4fa790, e=0x7fff9a4fa490) at /home/tom/Downloads/kde/kde-workspace/kwin/main.cpp:363
#25 0x00007ff357eceb9c in qt_x11EventFilter (ev=0x7fff9a4fa490) at kernel/qapplication_x11.cpp:435
#26 qt_x11EventFilter (ev=0x7fff9a4fa490) at kernel/qapplication_x11.cpp:423
#27 0x00007ff357edc1ab in QApplication::x11ProcessEvent (this=0x7fff9a4fa790, event=0x7fff9a4fa490) at kernel/qapplication_x11.cpp:3362
#28 0x00007ff357f039a9 in QEventDispatcherX11::processEvents (this=0x1221a70, flags=...) at kernel/qeventdispatcher_x11.cpp:132
#29 0x00007ff358cd494f in QEventLoop::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib64/libQtCore.so.4
#30 0x00007ff358cd4bd8 in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib64/libQtCore.so.4
#31 0x00007ff358cd9878 in QCoreApplication::exec() () from /usr/lib64/libQtCore.so.4
#32 0x00007ff35e2a2a63 in kdemain (argc=3, argv=0x7fff9a4fadb8) at /home/tom/Downloads/kde/kde-workspace/kwin/main.cpp:536
#33 0x0000000000400ace in main (argc=3, argv=0x7fff9a4fadb8) at /home/tom/Downloads/kde/kde-workspace/build/kwin/kwin_dummy.cpp:3
 
This is my kwinrc (I'm using KDE 4.9.5, by the way):

[$Version]
update_info=kwin_focus2.upd:kwin_focus2,kwin_on_off.upd:kwin_on_off,kwin.upd:kde3.0r1,kwin.upd:kde3.2Xinerama,kwin_focus1.upd:kwin_focus1,kwin_blacklist.upd:Blacklist-4.5,kwin_blacklist.upd:Blacklist-openSUSE-11.4,kwin3_plugin.upd:kde3.2,kwin_blacklist.upd:Blacklist-openSUSE-114,kwin_remove_effects.upd:kwin4.7_effects

[Blacklist][Blur]
Advanced Micro Devices=DRI R600:-:7.8.1,DRI R600:-:7.8.2
Ati=Radeon HD 3650:-:3.3.9901
Intel=Mesa DRI Intel(R) 945GM GEM 20100330 DEVELOPMENT x86/MMX/SSE2:-:1.4 Mesa 7.10,kio_uiserver,GM45 Express Chipset GEM 20100328:-:7.8.2,GM45 Express Chipset GEM 20091221:-:7.7.1,965GM GEM 20100328 2010Q1:-:7.8.2,965GM GEM 20091221 2009Q4:-:7.7.1,Ironlake Mobile GEM 20100328:-:7.8.2
NVIDIA=GeForce 6150/PCI/SSE2:-:195

[Blacklist][Lanczos]
Advanced Micro Devices=DRI R600:-:7.8.1,DRI R600:-:7.8.2
Intel=GM45 Express Chipset GEM 20100328:-:7.8.2,GM45 Express Chipset GEM 20091221:-:7.7.1,965GM GEM 20100328 2010Q1:-:7.8.2,965GM GEM 20091221 2009Q4:-:7.7.1,Ironlake Mobile GEM 20100328:-:7.8.2

[Compositing]
AnimationSpeed=3
Backend=OpenGL
CheckIsSafe=true
DisableChecks=false
Enabled=true
GLDirect=true
GLLegacy=false
GLMode=TFP
GLTextureFilter=0
GLVSync=true
GraphicsSystem=native
HiddenPreviews=4
OpenGLIsUnsafe=false
UnredirectFullscreen=false
XRenderSmoothScale=false

[Desktops]
Name_1=
Name_2=
Name_3=
Name_4=
Number=4

[Desktops-screen-1]
Name_1=
Number=1

[Effect-BoxSwitch]
AnimateSwitch=true
BackgroundOpacity=24
ElevateSelected=true
TabBox=false
TabBoxAlternative=false

[Effect-CoverSwitch]
TabBox=false
TabBoxAlternative=false

[Effect-FlipSwitch]
TabBox=false
TabBoxAlternative=false

[Effect-LookingGlass]
Radius=200

[Effect-TrackMouse]
Alt=false
Control=true
Meta=true
Shift=false

[Effect-Zoom]
EnableFocusTracking=true
EnableFollowFocus=true
InitialZoom=1
MousePointer=0
MouseTracking=0
ZoomFactor=2

[MouseBindings]
CommandActiveTitlebar1=Raise
CommandActiveTitlebar2=Start window tab drag
CommandActiveTitlebar3=Operations menu
CommandAll1=Move
CommandAll2=Toggle raise and lower
CommandAll3=Resize
CommandAllKey=Alt
CommandAllWheel=Nothing
CommandInactiveTitlebar1=Activate and raise
CommandInactiveTitlebar2=Start window tab drag
CommandInactiveTitlebar3=Operations menu
CommandTitlebarWheel=Switch to Window Tab to the Left/Right
CommandWindow1=Activate, raise and pass click
CommandWindow2=Activate and pass click
CommandWindow3=Activate and pass click
CommandWindowWheel=Scroll

[Plugins]
kwin4_effect_blurEnabled=true
kwin4_effect_boxswitchEnabled=false
kwin4_effect_coverswitchEnabled=false
kwin4_effect_cubeEnabled=false
kwin4_effect_cubeslideEnabled=false
kwin4_effect_dashboardEnabled=true
kwin4_effect_desktopgridEnabled=true
kwin4_effect_dialogparentEnabled=true
kwin4_effect_diminactiveEnabled=false
kwin4_effect_dimscreenEnabled=false
kwin4_effect_explosionEnabled=false
kwin4_effect_fadeEnabled=true
kwin4_effect_fadedesktopEnabled=false
kwin4_effect_fallapartEnabled=false
kwin4_effect_flipswitchEnabled=true
kwin4_effect_glideEnabled=false
kwin4_effect_highlightwindowEnabled=true
kwin4_effect_invertEnabled=false
kwin4_effect_loginEnabled=true
kwin4_effect_logoutEnabled=true
kwin4_effect_lookingglassEnabled=false
kwin4_effect_magiclampEnabled=false
kwin4_effect_magnifierEnabled=false
kwin4_effect_minimizeanimationEnabled=false
kwin4_effect_mousemarkEnabled=false
kwin4_effect_outlineEnabled=true
kwin4_effect_presentwindowsEnabled=true
kwin4_effect_resizeEnabled=false
kwin4_effect_scaleinEnabled=false
kwin4_effect_screenshotEnabled=true
kwin4_effect_sheetEnabled=false
kwin4_effect_showfpsEnabled=false
kwin4_effect_showpaintEnabled=false
kwin4_effect_slideEnabled=true
kwin4_effect_slidebackEnabled=false
kwin4_effect_slidingpopupsEnabled=true
kwin4_effect_snaphelperEnabled=false
kwin4_effect_startupfeedbackEnabled=true
kwin4_effect_taskbarthumbnailEnabled=false
kwin4_effect_thumbnailasideEnabled=false
kwin4_effect_trackmouseEnabled=true
kwin4_effect_translucencyEnabled=true
kwin4_effect_windowgeometryEnabled=false
kwin4_effect_wobblywindowsEnabled=false
kwin4_effect_zoomEnabled=true

[Style]
BorderSize=1
ButtonsOnLeft=MS
ButtonsOnRight=I_F_X
CustomButtonPositions=true
PluginLib=kwin3_oxygen
ShowToolTips=true

[TabBox]
ActivitiesMode=1
ApplicationsMode=0
DesktopMode=1
HighlightWindows=true
LayoutMode=0
LayoutName=big_icons
MinHeight=20
MinWidth=20
MinimizedMode=0
MultiScreenMode=0
SelectedLayoutName=Text
ShowDesktopMode=0
ShowOutline=true
ShowTabBox=true
SwitchingMode=0

[TabBoxAlternative]
ActivitiesMode=1
ApplicationsMode=0
DesktopMode=1
HighlightWindows=true
LayoutMode=0
LayoutName=thumbnails
MinHeight=20
MinWidth=20
MinimizedMode=0
MultiScreenMode=0
SelectedLayoutName=Text
ShowDesktopMode=0
ShowOutline=true
ShowTabBox=true
SwitchingMode=0

[Windows]
ActiveMouseScreen=false
AutoRaise=false
AutoRaiseInterval=750
AutogroupInForeground=true
AutogroupSimilarWindows=false
BorderSnapZone=10
CenterSnapZone=0
ClickRaise=true
DelayFocus=false
DelayFocusInterval=0
FocusPolicy=ClickToFocus
FocusStealingPreventionLevel=1
GeometryTip=false
HideUtilityWindowsForInactive=true
IgnoreFocusStealingClasses=kio_uiserver
InactiveTabsSkipTaskbar=false
MaximizeButtonLeftClickCommand=Maximize
MaximizeButtonMiddleClickCommand=Maximize (vertical only)
MaximizeButtonRightClickCommand=Maximize (horizontal only)
MoveMode=Opaque
MoveResizeMaximizedWindows=false
Placement=Smart
ResizeMode=Opaque
SeparateScreenFocus=false
ShadeHover=false
ShadeHoverInterval=250
SnapOnlyWhenOverlapping=false
TilingDefaultLayout=0
TilingOn=false
TilingRaisePolicy=0
TitlebarDoubleClickCommand=Maximize
WindowSnapZone=10

backtrace is bug #312712
Thanks for the rc - let's see whether it's reproducible with it.

Created attachment 76240 [details]
fix ith the other way

Me es mui stupido.

Next time i should perhaps try on vanilla master and not with a buch of custom pending patches. I can see the issue very much here (i mean: really! ;-)

The problem is that the tracking effect actually should reset the shader (also to align to the GL1 and XRender visuals) and reset the former modelview after (actually it should restore even more, but the attached patch will fix at least that)

Since the zoom effect doesn't play with shaders, it's also not responsible for doing such.

I tested your patch. For me, it cures the issues with the artifacts/eccentric rotation of the arcs. The tracking effect is not being zoomed in the patched version, but I guess I could live with that.

Thanks for caring and fixing the issue!

Not scaling is actually intended (since it's also the behavior on GL1 & XRender) - whether "right" is a different matter and not subject to this bug ;-)

If the patch from comment #19 works and is correct, please open a review request.

tssss... i once forgot to backlink the RR ... ;-)
https://git.reviewboard.kde.org/r/108252/

i twisted the approach after noticing that the zoom effect would also affect every other effect touching the generic shaders (scale in etc.) after it

first commit of https://git.reviewboard.kde.org/r/108359/ would also largely diminish the visual result (up to even fixing it) by ensuring an animated transition.

Git commit 2c8b25c7060dc55634018b2b0115218872ab92fa by Thomas Lübking.
Committed on 07/01/2013 at 21:16.
Pushed by luebking into branch 'master'.

reset generic shader after zoom

REVIEW: 108252

M  +4    -0    kwin/effects/zoom/zoom.cpp

http://commits.kde.org/kde-workspace/2c8b25c7060dc55634018b2b0115218872ab92fa

*** Bug 316239 has been marked as a duplicate of this bug. ***