//set swingArm to true to start a swing cycle

public boolean swingArm = false;
public int swingTick = 0;

public void onLivingUpdate() {
        super.onLivingUpdate();
    if(swingArm) {
            if (swingTick > 3 && swingTick < 9) {
                swingTick+=2;
            } else {
                swingTick++;
            }

            if(swingTick >= 24) {
                swingTick = 0;
                swingArm = false;
            }
        } else {
            swingTick = 0;
        }

        if (swingTick <= 16) {
            swingProgress = (float)swingTick / 8F;
        } else {
            swingProgress = 0F;
        }
}