Yes! That's it! the guns uses absolute coordinates.
I understand that when you say "d" you are saying deplacement (relative)?
p is position (absolute)?
c is cursor (direct input)? Only one cursor, c0.
m is mouse (rawinput)? Multple cursors, mX.
You are yet supporting two cursors, but using relative coordinates (m1d0 m1d1 m2d0m2d1) and works ok, but only with two mice.
And c0p0 c0p1 works with one lightgun, so it is giving absolute coordinates.But if I set this for both guns, the shoots are crossed between p1 and p2.
For two guns, with your logic, I think it might be m1Xp0 m1p1 m2p0m2p1.