Qt and OpenGl

Am an amateur programmer trying to learn to use Qt with OpenGl. I have programmed a rotating cube and am putting a portrait on each face as a texture. I have found though that the only way I can display the portrait on the cube faces is to first paint the portrait to the containing frame. I’m using bitmap images. Can anyone tell me why or lead me to the correct coding. Thanks muchly.

Can you provide more precise description of what works and what does not ? And what do you expect ?

Ie, something like :

  1. when drawing with this code :
    … code in BB code tags …
  2. I see this
    … image of problem (circle in red the problematic parts) …
  3. which is a problem because
    … precise description of problem …
  4. instead when drawing with this code :
    … other code in BB code tags …
    x) etc