[Qt-interest] QPainter background on QGLWidget

[Sean Hignett]

Hello all,

I am new to Qt, and working on some OpenGL sample code from the C++ Gui Programming book.  The VowelCube example demonstrates the ability to use QPainter "behind" OpenGL rendering.  It uses a radiant gradient background, and then paints an OpenGL cube over top (or so it is supposed to).

When I use the downloaded sample code with Qt 4.6 (vowelcode), everything works, but the actual OpenGL cube is not rendered.  If I comment out the QPainter based background (drawBackground), the cube will render.

http://www.informit.com/articles/article.aspx?p=1405557&seqNum=2
(code and example shown here)

Again, this is code taken from the C++ Gui Programming book based on Qt 4.3.  Has something changed since that version with respect to this functionality?  Trying get this to work as depicted is making me bald :)

Working on Qt 4.6 on OSX, but tried on Ubuntu as well, same result.

Thanks,
Sean