I am trying to build a projector wall with four Nvidia gpus at the moment and I am wondering if it is possible to use metamodes or some other technique to "trim" the video sent to the projectors. More specifically, the projectors might overlap each other in the final configuration and I am looking to be able to trim away the overlap in my X config.
I think I had it occur once, on accident, when I switched from a set of tiled 1680x1050 screens to some 1024x768 projectors, but I have not been able to reproduce it. I have been trying to adjust the metamode lines and the Xinerama layout in my xorg.conf, but at best I have only gotten duplicated screen areas.
I can post my xorg.conf tomorrow, I happen to be writing this at home and the computer in question is shut off in the lap.
Bonus question: it would be awesome if anyone had any insight on this, and I have researched it a lot -- is it very practical to do display transformation with the user tools that are out there now? The closest full on user tool seems to be xrandr 1.3 (it has a --transform option taking in a new viewport matrix), but that simply segfaults for my when I tried it. I expect Nvidia would have to add 1.3 support to their driver, and even then I would probably be SOL due to Xinerama and RANDR not playing together.