Enemy.cs

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class Enemy : MonoBehaviour {

	private readonly float LookedDistance = 2f;
	private Player player;
	private CharacterControl cc;

	public enum Status {
		None,
		Warning,
		Discovery
	};

	public Status mystatus;

	public GameObject NoticeObject;

	// Use this for initialization
	void Start () {
		cc = GetComponent<CharacterControl> ();
		player = GameObject.Find ("Player").GetComponent<Player> ();
		SetCallback (CreateNotice);
	}
	
	// Update is called once per frame
	void Update () {
		Search ();
	}

	public float getDistance () {
		Vector3 dv = player.transform.position - transform.position;
		return Mathf.Pow ((dv.x * dv.x + dv.y * dv.y + dv.z * dv.z), 0.5f);
	}
		
	public void Search () {

		if (mystatus != Status.Discovery) {

			// 目線
			RaycastHit hit;
			if (Physics.Raycast (transform.position, transform.forward * LookedDistance, out hit)) {
				if (hit.collider.tag == "Player") {
					if (hit.distance < LookedDistance / 2f) {
						OnChangeStatus (Status.Discovery);
					} else {
						OnChangeStatus (Status.Warning);
					}
				}
			} else {
				OnChangeStatus (Status.None);
			}

			// 距離と足音
			if (getDistance () < LookedDistance) {
				if (player.getWalkVolumeStatus () == Volume.Small)
					OnChangeStatus (Status.Warning);
				if (player.getWalkVolumeStatus () == Volume.Loud)
					OnChangeStatus (Status.Discovery);
			} else {
				OnChangeStatus (Status.None);
			}
		} else {

			transform.LookAt (player.transform.position);

			if (getDistance () > LookedDistance) {
				OnChangeStatus (Status.None);
			}
		}

		print (mystatus);
	}

	public delegate void Callback (Status st);
	public Callback callback;

	public void SetCallback (Callback c) {
		callback = c;
	}

	public void OnChangeStatus (Status st) {
		mystatus = st;
		if (mystatus != Status.None) {
			if (callback != null) {
				callback (mystatus);
			}
		}
	}

	public void CreateNotice (Status st) {
		if (transform.FindChild ("Notice(Clone)") != null) {
			transform.FindChild ("Notice(Clone)").GetComponent<Notice> ().ChangeStatus (st);
			return;
		}

		GameObject obj = Instantiate (NoticeObject);
		obj.transform.SetParent (transform);
		obj.transform.localPosition = Vector3.up * (cc.getHeight () + 1f);
		obj.GetComponent<Notice> ().Created (st);
	}
}