   Off-screen OpenGL rendering... Again!
  Hi community. I'm terribly lost with OpenGL and offscreen rendering. Hope for someone fishing me out of this "mare nigrum". Yes, I'm a newbie to OpenGL and this forum.Here is what I want to do: Render and store a high-resolution image of a scene that I am displaying in a GL context (provided by a QGLWidget, that is a Qt Window). My scene is purly in 2D, and the high-resolution screenshot to be rendered has varying size, dependent on the size of the scene that is available.What is the most simple-fashioned way to do this? Apparently, I am heading for a cross-platform solution (this is why I use OpenGL and Qt). I have a clue how I would do it in DirectX: I would try to render the scene simply into a new RenderTarget. But how to achieve this in OpenGL?I've already read this thread, but it didn't help me out.Thanks a lot for any help!   
  The GL counterpart of RenderTargets are Framebuffer Objects (FBOs), Qt has a nice class on top of FBOs called QGLFramebufferObject, which you can use, see:http://doc.trolltech.com/4.2/qglframebufferobject.html   