Background color of GLWidget

[mullwaden]

Is it possible to set the background color of a glWidget? If I use a command such as glClearColor(...) then the whole widget takes that color even though the actual viewport of the openGL might not be covering the whole widget.

[wysota]

What do you mean it might not be covering the whole widget?

[mullwaden]

Well with a code like this for example:

double side = std::min(width / ratio, height);
glViewport(int(width - side*ratio) / 2, int(height - side) / 2, int(side*ratio), int(side));

where width and height is the widgets extents, I would get an image thats always a certain ratio 4:3 or 16:9 for example.

[wysota]

Ok, but the rest is still occupied by the gl context, so you have to use OpenGL means to change the background color. I think glClear() should clear everything, not only the GL viewport. If I'm mistaken and you are talking about something else, then try using QPalette and changing the background role colour.