[Xorg] Question about X Server Internal

[Amir Bukhari]

I have some basic Questions on X Server. may be this very simple for
experience programmer on X Server.
1- what I am trying since one week, is to find how a Window (including
GC operations) is drawn to screen. I search for the code which write to
the framebuffer of the video card. I know that cfb and mfb do that, but
still not find where they access the framebuffer. The video card driver
should export the framebuffer for its device to ddx layer. Could you
describe how cfb code access the framebuffer or simple which structure
store the framebuffer address?.

2- is there a different between XImage and Pixmap?

3- does the X server save always a copy of a window image, so that when
copying the window to others window, also the portion of the window
which not visible, is taken?

for me Question 1 is important.

-Amir