server questions

Questions on hardware panning in XFree implementation:

This is the feature that allows one to define a screen size larger than 
the displayable
area, and then performs a hardware pan when the cursor is moved to an 
edge of the viewable.

Is it an extension? Where is the functionality implemented?

Is it possible to extend the idea to allow some amount of client side 
control of the viewed area?

I wonder if there is a natural limitation to the max available size that 
can be configured. EG some current graphics
cards have huge memory.  If this is texture store, is it still possible 
to somehow apply it to panning? I'm
aware of some limitations where 3D engines are involved.

I would like to see some control in allocation of the onboard memory so 
that panning-freaks, pixmap-freaks,
or 3D freaks could tune the hardware to their liking. Would appreciate a 
push in the right direction if this
work is possible.

Thanks,

Stuart Kreitman