How to warp display

I am working with a loosely calibrated tiled projector display wall.  I 
would like to integrate our display with XDMX (http://dmx.sourceforge.net/) 
but that only handles well calibrated rectangular displays.  The idea behind 
loosely calibrated display walls is that the user quickly puts together the 
display and the system does all of the work and prewarps the display images 
so that they are displayed correctly by the projectors.

I would like the ability to take the image that would be created by the 
XFree86 Display server and warp it in some programmable manner (using 
texture mapping, color maps, ...) and then display this image instead.  Does 
anyone have any advice on where I might hook into the Xserver to use and 
modify the frame buffer (hopefully in an efficient manner)?  I need advice 
on whether this is possible and where to start.

Currently large display walls have to use well calibrated projectors to be 
able to display a linux desktop and this requires special mounting and 
possibly a lot of work.  If we could get this working there is a chance that 
it could integrate well with dmx and chromium creating a well optimized 
large display that could be quickly setup and requires little effort to 
calibrate.


Thanks

_________________________________________________________________
Is your PC infected? Get a FREE online computer virus scan from McAfee® 
Security. http://clinic.mcafee.com/clinic/ibuy/campaign.asp?cid=3963