/*
* This simple method moves the gun to the bearing that we predict the
* enemy will be by the time our bullet will get there.
* the 'absbearing' method can be found in the helper functions section
* the nextX and nextY method can be found in the 'Enemy' class description
*/

void doGun() {

        //works out how long it would take a bullet to travel to where the enemy is *now*
        //this is the best estimation we have, without using a complicated iteration
        long time = getTime() + (int)(target.distance/(20-(3*firePower)));

        //offsets the gun by the angle to the next shot based on linear targeting provided by the enemy class
        double gunOffset = getGunHeadingRadians() - absbearing(getX(),getY(),target.guessX(time),target.guessY(time));
        setTurnGunLeftRadians(NormaliseBearing(gunOffset));
}