Sorry, to add xdpyinfo gives
default screen number: 0 number of screens: 1
screen #0: dimensions: 2560x1200 pixels (678x318 millimeters)
which is indeed what's happening: each screen can pan vertically. 2560=1280 times 2, but where does the 1200 come from?
Sorry, to add xdpyinfo gives
default screen number: 0
number of screens: 1
screen #0:
dimensions: 2560x1200 pixels (678x318 millimeters)
which is indeed what's happening: each screen can pan vertically. 2560=1280 times 2, but where does the 1200 come from?