On Mon, May 25, 2009 at 07:15:33AM -0700, Jerome Guilmette wrote: > Hi everyone, > > I hope this is the good list to send my question to for it is a rather a > specific matter. All my tests were done using an NVIDIA GeForce 8600M, driver > version 180.29, under the Fedora 10 OS. > > Here is my issue: I have a program that takes a few screenshots of an > application (window) and saves it into a file. I discovered that, while > taking a snapshot of an application running an openGL viewport, i.e. > glxgears, and switching to another X server, I was not able to save the images > in their integrity, the openGL viewport wasn't displayed. So the raw content > of an openGL viewport isn't available while we are in another X Server than > the one the program is running into. So would it mean that only one openGL > context per X server is possible?
I'm not sure how you concluded that only one context per X server is possible from the fact that you can't access a window's pixels when the server is not on the active virtual terminal. You can definitely have multiple contexts per X server. > In a multiple X sessions context, is there a way to have access to the > rendered openGL viewport pixels while being currently on a different X server > using standard X functions? In any case, what exactly are the mechanisms in > place? No, you can't do that. When you VT-switch away from the current X server, all windows are clipped so that no rendering occurs to them, and OpenGL processing is suspended. The non-active X server is not supposed to touch the hardware at all, to allow the active X server to use it. > Any inputs would be very much appreciated, might it be a link to more > documentation or a direct answer. _______________________________________________ xorg mailing list xorg@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/xorg