oz_poc/unity_project/Assets/BeatEmUp_GameTemplate3D/Scripts/Health/HealthSystem.cs

using UnityEngine;

public class HealthSystem : MonoBehaviour {

	[Header("Health Settings")]
	public int MaxHp = 20;
	public int CurrentHp = 20;
	public bool invulnerable;

	#if UNITY_EDITOR
	[HelpAttribute("Change these settings if you want to change the player portrait or player name in the healthbar located in the upperleft corner of the screen.", UnityEditor.MessageType.Info)]
	#endif

	[Header("Healthbar Settings")]
	public Sprite HUDPortrait;
	public string PlayerName;

	public delegate void OnHealthChange(float percentage, GameObject GO);
	public static event OnHealthChange onHealthChange;

	void Start(){
		SendHealthUpdateEvent();
	}

	//substract health
	public void SubstractHealth(int damage){
		if(!invulnerable){

			//reduce hp
			CurrentHp = Mathf.Clamp(CurrentHp -= damage, 0, MaxHp);

			//Health reaches 0
			if (isDead()) gameObject.SendMessage("Death", SendMessageOptions.DontRequireReceiver);
		}

		SendHealthUpdateEvent();
	}

	//add health
	public void AddHealth(int amount){
		CurrentHp = Mathf.Clamp(CurrentHp += amount, 0, MaxHp);
		SendHealthUpdateEvent();
	}

	//health update event
	void SendHealthUpdateEvent(){
		float CurrentHealthPercentage = 1f/MaxHp * CurrentHp;
		if(onHealthChange != null) onHealthChange(CurrentHealthPercentage, gameObject);
	}

	//death
	bool isDead(){
		return CurrentHp == 0;
	}
}