well depends on what u want to do. In the case that you specified, if you are simply finding a player between his aiming and his end aiming you can simply do get_user_aiming. If you are trying to find out if a player is on a line that is not from a player's crosshairs to a player's end aim point, you could circle through 1-get_maxplayers() and see if they are on the line with simple algebra.