Changing Xorg-Configuration on the fly

[Leif Bergerhoff]

Hello,

as part of a project I'm coding a calibration tool and I'm looking for a way 
to tell the xserver to change some of its settings on the fly. Yes, I know 
the xrandr-extension, but I don't think its what I need (if I am wrong feel 
free to correct me...).

In the ServerLayout Section of the xorg.conf I defined the following Xinerama 
settings:

	Screen		"Screen0" Absolute 0 0
	Screen		"Screen1" Absolute 1585 855
	Screen		"Screen2" Absolute 0 860
	Screen		"Screen3" Absolute 1585 0

Now I want to change the defined X- and Y-coordinates while the xserver is 
running - of course without restarting it.

How can I do this, or where can I find appropriate functions that will help me 
to do the job?

Thanks in advance,
Leif