Sharing between QGLContext and QOpenGLContext

[wrosecrans]

So, I have an instance of a subclass of QGLWidget, "viewport." I also have a "compositor" with a QOffscreenSurface, a QOpenGLContext and a QOpenGLFrameBufferObject. I want to draw in my viewport using the FBO as a texture. The compositor needs to be able to create its own OpenGL context so that it works regardless of whether the viewer exists or is active. (The app has a "render only" mode where no visible GUI stuff is displayed -- it just writes a file. The viewport is only for interactive mode.)

QGLWidget::context() gets me a QGLContext, which I want to share with the QOpenGLContext. Is this the correct way to do it?

viewport->context()->contextHandle()->setShareContext(compositor->context);

Are there any gotchas related to sharing state between the two sorts of contexts that I should know about? Can I expect this to be portable between platforms?

[SGaist]

Involuntary "Duplicate":http://qt-project.org/forums/viewthread/33472/