[Interest] OpenGL Window Example: Terrible resize window performance

[Till Oliver Knoll]

Am 13.07.14 15:47, schrieb Till Oliver Knoll:
> Hi,
> 
> anyone else noticed that the performance is terrible when resizing the
> window of the "OpenGL Window Example"?

A quick experiment confirmed my suspicion that it must have anything to
do with the "animation triggering": when in main.cpp I

  setwindow.setAnimating(false);

then the resizing is smooth. Off course the triangle does not rotate
(funnily it does while resizing the window ;)).

As the animation basically posts an update request in
OpenGLWindow::renderLater:

  QCoreApplication::postEvent(this, new QEvent(QEvent::UpdateRequest));

and also keeps track of "pending updates" with a member variable
(m_update_pending) this must somehow interfere (at least on OS X) with
the "resize events" sent by the OS.

So far my quick'n'dirty analysis and educated guesswork...

Cheers, Oliver