sure, zaphod mode. You'll lose the ability to drag windows across the screens, though, since they become completely independant. IIRC zaphod mode with current Xorg / OS drivers has some trouble due to xrandr changes though.
It's a simliar idea, but dragging is possible. The idea is having a mid layer which takes an input in the virtual sceen area (say 3080*1050, 1400+1680), if the area that requires a re-draw is outside one single monitor (a graph whose x-coordinate from 1280 to 1623, say, then both monitors get re-drawed respectively, the 1400 one first, then the 1680 one), otherwise it will look like the zaphod mode. Since the time differnce between drawing the two screen is not big enough to be noticed, it should work.
Usually the dragging is for normal window, if the drawing is comupationally intense (such as video or opengl apps), just leave the window in black while it straddles the two monitors (and recover after it goes to one single monitor). I think that's also the practice for windows. My media player becomes black when I move it between the two windows.
Currently viewspace is a single x * y block of memory that you have to fit all monitors in. (and very easily run into problem with them fitting in) What you want is something like this. http://corbinsimpson.com/content/shattered It'll be done when it's ready.
Exactly, thank for pointing out.
I think this part should be reside in the driver, right?
Just a quick note to say that the current development version of compiz does tiling of textures to work around the maximum texture size limitation. It is still not ready for everyday use, but that functionality is already present.
Also, if you disable your DE from drawing the wallpaper and let compiz draw it, you probably won't even notice any problems with the maximum texture size. It only hits windows that exceed 2048, and the only one that generally does that is the root window (though, to be fair, I guess you could have any window that large, it does seem likely that most people don't).
Of course, this assumes that the problem you are having is actually with the maximum 3D texture size. It is possible that you are actually hitting the maximum 3D size, which is a different limitation.