// to be called whenever the contents of the backpack change
public void UpdateMeters()
{
if (backpackController == null)
{
backpackController = FindObjectOfType <BackpackController>();
}
UpdateMeter(healthBar, backpackController.TotalHealth());
UpdateMeter(manaBar, backpackController.TotalMana());
UpdateMeter(staminaBar, backpackController.TotalStamina());
}
