QOpenGLWidget Performance Issue

[JorganMones]

When combining a QOpenGLWidget with a regular QWidget on the same form, performance is impaired such that interaction with the other widgets is 'sluggish'.

Below is an example:

• With QGLWidget, slider dragging the slider is 'snappy'
• With QOpenGLWidget, slider dragging is 'sluggish'

    QSlider *testWidget = new QSlider(Qt::Horizontal, this);
    testWidget->resize(400,30);

    QOpenGLWidget* oglWidget = new QOpenGLWidget(this);
    //QGLWidget* oglWidget = new QGLWidget(this);
    oglWidget->resize(60,60);
    oglWidget->move(0,100);

My questions are:

• Why is QOpenGLWidget behavior so different?
• Is there a configuration for QOpenGLWidget that provides for 'more responsive' rendering?
• Is QGLWidget still viable for new development, even though deprecated?

EDIT :

• Windows 10
• Qt Versions 5.5 and 5.7

EDIT 3 :
These open bug report might explain the cause of the issue:

https://bugreports.qt.io/browse/QTBUG-54034?jql=text ~ "QOpenGLWidget"
https://bugreports.qt.io/browse/QTBUG-45192

Wrapping in native QWindow has issues.

Is there a solution that still uses QOpenGLWidget (i.e. some way to disable scene composition with other widgets? )

Thanks!

[SGaist]

Hi and welcome to devnet,

You should also add which version of Qt you are using as well as the OS you are running.

In any case, you should take a look a the bug report system to see if there's something about it.