using UnityEngine;
using System.Collections;

public class ShakeCamera : MonoBehaviour
{

    // 震动标志位
    private bool isshakeCamera = true;

    // 震动幅度
    public float shakeLevel = 3f;
    // 震动时间
    public float setShakeTime = 0.2f;
    // 震动的FPS
    public float shakeFps = 45f;

    private float fps;
    private float shakeTime = 0.0f;
    private float frameTime = 0.0f;
    private float shakeDelta = 0.005f;
    private Camera selfCamera;

    private Rect changeRect;

    void Awake()
    {
        selfCamera = Camera.main;
        changeRect = new Rect(0.0f, 0.0f, 1.0f, 1.0f);
    }

    // Use this for initialization
    void Start()
    {
        shakeTime = setShakeTime;
        fps = shakeFps;
        frameTime = 0.03f;
        shakeDelta = 0.005f;
    }

    // Update is called once per frame
    void Update()
    {
        if (isshakeCamera)
        {
            if (shakeTime > 0)
            {
                shakeTime -= Time.deltaTime;
                if (shakeTime <= 0)
                {
                    changeRect.xMin = 0.0f;
                    changeRect.yMin = 0.0f;
                    selfCamera.rect = changeRect;
                    isshakeCamera = false;
                    shakeTime = setShakeTime;
                    fps = shakeFps;
                    frameTime = 0.03f;
                    shakeDelta = 0.005f;
                }
                else
                {
                    frameTime += Time.deltaTime;

                    if (frameTime > 1.0 / fps)
                    {
                        frameTime = 0;
                        changeRect.xMin = shakeDelta * (-1.0f + shakeLevel * Random.value);
                        changeRect.yMin = shakeDelta * (-1.0f + shakeLevel * Random.value);
                        selfCamera.rect = changeRect;
                    }
                }
            }
        }
    }

    public void shake()
    {
        isshakeCamera = true;
    }
}