Accessing an openGL viewport's pixels on multiple X servers
Jerome.Guilmette at CadensImaging.com
Mon May 25 07:15:33 PDT 2009
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?
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?
Any inputs would be very much appreciated, might it be a link to more
documentation or a direct answer.
Thank you very much,
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