Qt 5.3. Painting on QOpenGLFrameBuffer

Question

Painting on a QOpenGLFrameBuffer in the Qt 5.3 (beta) seems a bit elusive to me I can get only a black image. (I Haven't tried previous versions of Qt5 but haven't find any notice of some problem in this area)

Searching around I've copied the exact sample at http://dangelog.wordpress.com/2013/02/10/using-fbos-instead-of-pbuffers-in-qt-5-2 .

Adding just before the end of createImageWIthFBO()

  QImage img=fbo.toImage();
  img.save("d:/tmp.jpg");

to inspect the fresh result with no further operations but the resulting image is black.

Am I missing something? perhaps some platform problem? (Win 8.0 here)

Answer 1

The problem was in the instruction format.setMajorVersion(3) , that 3 should be a 2 and all works as expected. (I guess some implementations of opengl are more picky in this detail)