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

namespace FPS{

	public enum PlayerState{
		Idle, Walking, Running, Jumping
	}

	[RequireComponent(typeof(CharacterController), typeof(AudioSource))]
	public class PlayerController : MonoBehaviour {

		[Range(0.1f, 2f)]
		public float walkSpeed = 1.5f;
		[Range(0.1f, 10f)]
		public float runSpeed = 3.5f;

		private CharacterController charaController;

		void Start () {
			charaController = GetComponent<CharacterController> ();
		}
			
		void Update () {
			Move ();
		}

		void Move(){
			float moveH = Input.GetAxis ("Horizontal");
			float moveV = Input.GetAxis ("Vertical");
			Vector3 movement = new Vector3 (moveH, 0, moveV);

			if (movement.sqrMagnitude > 1) {
				movement.Normalize ();
			}

			// ★修正
			// 歩行とランを切り替える。
			if (Input.GetKey (KeyCode.LeftShift)) {
				charaController.Move (movement * Time.fixedDeltaTime * runSpeed);
			} else {
				charaController.Move (movement * Time.fixedDeltaTime * walkSpeed);
			}
		}
	}
}
C#