Help with glReadPixels

[malancha]

Hi, I'm trying to capture the image in an OpenGL window even when the window is partially or fully hidden by other windows. I can't use glReadPixels in such a case, so is there any other way to directly grab the color values?

Thanks in advance.

[Mazy]

pixels that are hidden are by specification undefined, if you need to readback a whole rendered scene you should go for PBuffers for now.. A new extension capable of rendering direct to textures are in progress but not done in a few month i guess.

[malancha]

Thanks -- unfortunately I haven't the foggiest idea about PBuffers. Would using PBuffers compromise on platform independence? Assuming that it wouldn't, can anyone point me to a tutorial?