Housekeeping.

weapons/holster.go

@@ -17,6 +17,13 @@ func NewHolster() *Holster {
 	return holster
 }
 
+func (h *Holster) SetActiveWeapon(wt gamedata.WeaponType) {
+	_, ok := h.guns[wt]
+	if ok {
+		h.activewp = wt
+	}
+}
+
 func (h *Holster) GetActiveWeapon() Weapon {
 	return h.guns[h.activewp]
 }