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Diffstat (limited to 'examples/opengl/hellogl2/doc/hellogl2.rst')
| -rw-r--r-- | examples/opengl/hellogl2/doc/hellogl2.rst | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/examples/opengl/hellogl2/doc/hellogl2.rst b/examples/opengl/hellogl2/doc/hellogl2.rst index 1223e138c..3471ebf30 100644 --- a/examples/opengl/hellogl2/doc/hellogl2.rst +++ b/examples/opengl/hellogl2/doc/hellogl2.rst @@ -4,6 +4,20 @@ Hello GL2 Example The Hello GL2 example demonstrates the basic use of the OpenGL-related classes provided with Qt. +In this example the widget's corresponding top-level window can change several +times during the widget's lifetime. Whenever this happens, the QOpenGLWidget's +associated context is destroyed and a new one is created, requiring us to clean +up the GL resources. + +The equivalent C++ example does this cleanup on emission of the +QOpenGLContext.aboutToBeDestroyed() signal. However, in Qt for Python, we +cannot rely on this signal when it is emitted from the destructor. + +Therefore, we do the cleanup in GLWidget.hideEvent(). + +This will be followed by an invocation of initializeGL() where we can recreate +all resources. + .. image:: hellogl2.png :width: 400 :alt: Hello GL2 Screenshot |