Solved Using old QGLwidget from Qt 4.8.2

[QttCoreTester]

I know QGLwidget is obsolete but I have application that use it. There is a widget that was inherited from Qglwidget. Recently after new Intel graphics driver updates I observed a crash.

Many gl calls from the Widget throws floating point exception. Is there someone who had a similar experience.

[SGaist]

Hi and welcome to devnet,

Since you updated the driver, it could be an issue of the driver.

Are you really tied to 4.8.2 ? If locked to Qt 4, then try with 4.8.7 which is the latest and last from that series. Otherwise, please consider moving to Qt 5.

[QttCoreTester]

Hi Thank you.

I tried gl calls directly, there is no exception. But once Qglwidget is instantiated, calls "InitGL" most gl calls starts to throw exception. So, one cannot blame the driver update.

Qt5 is not an option. Maybe 4.8.7 is an option, Are 4.8.2 and 4.8.7 compatible with each other.

[mrjj]

@QttCoreTester said in Using old QGLwidget from Qt 4.8.2:

Are 4.8.2 and 4.8.7 compatible with each other.

Should be.

[QttCoreTester]

I tried Qt 4.8.7, OpenGL calls still crashes on Windows 10 with new Intel graphics drivers.

[SGaist]

Check if it's really the latest driver, if not update, otherwise go back to the previous version.

[mrjj]

@QttCoreTester
Hi
Its odd that QGLwidget crashes but direct openGL calls are fine (if i understood you right) so
must be something in QGLwidget that is no longer compatible with that intel driver.

Seems to be the end of the road for QGLwidget.
I wonder if its Intel related or it would crash on newer RTX cards too.

[QttCoreTester]

@SGaist
I am using the latest driver 27.20.100.8336. The Problem occurs with newer drivers, older drivers are working fine.

@mrjj
Yes you are right.

No idea on what happens on other Cards. Maybe it is specific to Intel.

[SimonSchroeder]

My best guess is that newer drivers might have lost some functionality. Initially, OpenGL used calls like glVertex(), glLight, etc. Modern OpenGL has found replacements for these. It could be that Intel is only implementing EGL, which would be a lot like modern OpenGL. This would also mean that old functionality is not available anymore. Does the driver list which versions (and maybe profiles) of OpenGL it is supporting? (Asking this question I also remember that somehow a more strict profile could be configured in your app.)

[QttCoreTester]

@SimonSchroeder The driver release notes just says it support OpenGL 4.6, no more info.

[QttCoreTester]

The issue is no longer observed with the latest Intel graphics driver beta version(27.20.100.8581). Fixed in latest release version 27.20.100.8587