Bug 309510

Created attachment 74986 [details]
Original Desktop

the GL_INVALID_ERRORS would explain the distortion. Could you please provide the output of:
qdbus org.kde.kwin /KWin supportInformation

Created attachment 74987 [details]
Desktop Effect with Artifacts

Created attachment 74988 [details]
xsession-errors

Created attachment 74989 [details]
Output of command "qdbus org.kde.kwin /KWin supportInformation"

Created attachment 74990 [details]
Use of OpenGL 2 Shaders disabled

(In reply to comment #2)
> the GL_INVALID_ERRORS would explain the distortion. Could you please provide
> the output of:
> qdbus org.kde.kwin /KWin supportInformation

See attached file

could you please try to disable the option for useBlur? Unfortunately there is no config option for it, so it's

kwriteconfig --file kwinrc --group Effect-Logout --key UseBlur --type bool false

afterwards just restart kwin with:
kwin --replace &

To enable the blur again use the same command with a true at the end.

Created attachment 74991 [details]
With option useBlur disabled

(In reply to comment #8)
> could you please try to disable the option for useBlur? Unfortunately there
> is no config option for it, so it's
> 
> kwriteconfig --file kwinrc --group Effect-Logout --key UseBlur --type bool
> false
> 
> afterwards just restart kwin with:
> kwin --replace &
> 
> To enable the blur again use the same command with a true at the end.

Ok I have done that and the visual artifacts go away as shown in the 4th snapshot. But return when I enable blur again. But likewise the blur & desaturation when showing the widget dashboard works correctly.

(In reply to comment #10)
> Ok I have done that and the visual artifacts go away as shown in the 4th
> snapshot. But return when I enable blur again. But likewise the blur &
> desaturation when showing the widget dashboard works correctly.
In the dashboard it is implemented in a different way.

Please provide your screen dimensions and the output of:
glxinfo -l

Btw. would you be able to apply patches to KWin and compile a tested version?

Created attachment 74993 [details]
Output of command "glxinfo -l"

(In reply to comment #11)
> (In reply to comment #10)
> > Ok I have done that and the visual artifacts go away as shown in the 4th
> > snapshot. But return when I enable blur again. But likewise the blur &
> > desaturation when showing the widget dashboard works correctly.
> In the dashboard it is implemented in a different way.
> 
> Please provide your screen dimensions and the output of:
> glxinfo -l
> 
> Btw. would you be able to apply patches to KWin and compile a tested version?

Screen dimensions are 1600x900.
Output of "glxinfo -l"

Yes I should be able to apply patches to KWin, compile and test.

Let's first try whether mesa tells us where the error is.

Please run kwin with the environment variable MESA_DEBUG being set:
MESA_DEBUG=1 kwin --replace &

This should print to stderr what caused the error. For a full overview of environment variables have a look at http://www.mesa3d.org/envvars.html - there might be more interesting ones to figure out the problem.

(In reply to comment #14)
> Let's first try whether mesa tells us where the error is.
> 
> Please run kwin with the environment variable MESA_DEBUG being set:
> MESA_DEBUG=1 kwin --replace &
> 
> This should print to stderr what caused the error. For a full overview of
> environment variables have a look at http://www.mesa3d.org/envvars.html -
> there might be more interesting ones to figure out the problem.

When I bring up the logout dialogue the lines

Mesa: User error: GL_INVALID_OPERATION in glBlitFramebufferEXT(bad src/dst multisample pixel formats)
kwin(9415) KWin::checkGLError: GL error ( Render blur texture ):  "GL_INVALID_OPERATION"

are print to stderr, until I close the logout dialogue.

Also some additional information, shown below, is also printed to stderr before I bring up the logout dialogue. I don't know if that will help

Running "MESA_DEBUG=1 LIBGL_DEBUG=verbose kwin --replace >/dev/null &"
gives:

function is no-op
libGL: OpenDriver: trying /usr/lib64/dri/nouveau_dri.so
libGL: Can't open configuration file /etc/drirc: No such file or directory.
libGL: Can't open configuration file /home/terry/.drirc: No such file or directory.
libGL: Can't open configuration file /etc/drirc: No such file or directory.
libGL: Can't open configuration file /home/terry/.drirc: No such file or directory.
Mesa warning: couldn't open libtxc_dxtn.so, software DXTn compression/decompression unavailable
libGL: OpenDriver: trying /usr/lib64/dri/nouveau_dri.so
libGL: Can't open configuration file /etc/drirc: No such file or directory.
libGL: Can't open configuration file /home/terry/.drirc: No such file or directory.
libGL: Can't open configuration file /etc/drirc: No such file or directory.
libGL: Can't open configuration file /home/terry/.drirc: No such file or directory.
Mesa warning: couldn't open libtxc_dxtn.so, software DXTn compression/decompression unavailable
Mesa: User error: GL_INVALID_OPERATION in glBlitFramebufferEXT(bad src/dst multisample pixel formats)
kwin(9537) KWin::checkGLError: GL error ( Render blur texture ):  "GL_INVALID_OPERATION" 
Mesa: User error: GL_INVALID_OPERATION in glBlitFramebufferEXT(bad src/dst multisample pixel formats)
kwin(9537) KWin::checkGLError: GL error ( Render blur texture ):  "GL_INVALID_OPERATION" 
Mesa: User error: GL_INVALID_OPERATION in glBlitFramebufferEXT(bad src/dst multisample pixel formats)
...(repeated until logout dialogue closed)

> multisample
seems the same issue as bug #308385 - let's wait whether 4.9.3 fixes this issue

It's likely the "multisample-by-default" issue, see bug #308385

*** This bug has been marked as a duplicate of bug 308385 ***

blast, while comment #18 is true (likely) i did not mean to alter this bug... sorry.

This issue is fixed in 4.9.3