opengl off-screen rendering

I am using off screen rendering using opengl FBO and glut on (a MAC OS X 10.6, OpenGL 2.1). The program involves movement of multiple 3D objects.

The program seems to be working fine except that I am required to include an option where the off screen buffer contents are not swapped to the on screen buffer. Hence you do not see anything on the screen. I want to know if the program is working as it should be in this mode when nothing is seen on screen - ie 3D movements etc work fine as usual. Is there a utility that can read offscreen buffer and display it onscreen while my process runs separately.

Alternatively, are there other ways to achieve this? That is to hide the onscreen window while rendering offscreen using FBO and be sure that the 3D objects are being rendered correctly. I hope I am clear in my question.

Appreciate any comments/suggestions.

I want to know if the program is working as it should be in this mode when nothing is seen on screen - ie 3D movements etc work fine as usual.

Is there some reason you would expect it to not work? I’m not really sure about what it is you’re trying to verify.

Is there a utility that can read offscreen buffer and display it onscreen while my process runs separately.

You mean without specifically coding the two processes to talk to one another? I highly doubt it.

Maybe GLIntercept can do that.

Thanks. I will try it.

@Alfonse: I want to check the correctness of my code.