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Opengl window resize speed

  • Greetings Qt enthusiasts,

    On Windows since Qt 4.7.4 resizing an opengl window is slower than before.

    This can be demonstrated using the Demonstrations/Boxes example.

    • When you resize it with 4.7.2 the viewport gets updated immediately.
    • When you resize it with 4.7.4 or 4.8 RC the viewport update is delayed.

    Is it related to Opengl threading ? Is there a way to increase viewport updates during resize ?


  • I honestly don't know. You could have a look for existing bug reports and report this if one doesn't already exist.

    Then if you're feeling adventurous you could take a look to see if you can find out why this happens by profiling a simple application with a QGLWidget to see where it takes the time compared to 4.7.2.

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