newbie question; how to dump a window to a bitmap file (i.e. gif or png)

[Armin S. A. Roehrl]

Sorry to ask a maybe trivial question.
Please point me to some tutorials/FAQs. Thx.

I create a window using XCreateWindow, etc..
Then I draw in it by calling e.g. XFillArc, etc.

Are there any functions/routines/libraries
to save the window into a bitmap (e.g.
.gif or .png) format?
I don't want to use xv or a similar
external program, I would like to drive
it from the C code directly.

Thanks a lot.

Armin