Explanation:
 
This line determines whether the enemy is within one square of the obstruction ahead of Torque (and hence whether the enemy can be fragged).

~v1 is the number of squares that the enemy is in front of Torque. This must be between 1 and 3 for the enemy to still be in a position where it can be fragged.

~v2 is the number of squares that the enemy is to either side of Torque. This must be between -1 and 1 for Torque to be able to frag the enemy.

So if both of these conditions are met, then Torque launches a missile into the obstruction, to hit the enemy with missile splash.