closechk_ -1 4 Explanation:

This routine is specifically for when Torque is facing West.

It calculates the distance that the enemy is in front of and to the side of Torque, and then checks to see whether there is a clear path to launch a grenade into, so that it will detonate next to the enemy. If there is a clear path, then Torque sets the grenade fuse to the necessary distance and launches it.