Unity3D笔记 愤怒的小鸟<六> 弹弓发射小鸟

using UnityEngine;
using System.Collections;

public class slingShot : MonoBehaviour
{

    /// <summary>
    /// 小鸟
    /// </summary>
    public GameObject bird;
    /// <summary>
    /// 弹弓拉伸的声音
    /// </summary>
    public AudioClip slingShotSound;
    /// <summary>
    /// 飞行声音
    /// </summary>
    public AudioClip flyingSound;
    /// <summary>
    /// 弹弓橡皮筋颜色
    /// </summary>
    public Color myColor;
    /// <summary>
    /// 是否按下鼠标
    /// </summary>
    private bool isClick = false;
    /// <summary>
    /// 发射出去的小鸟
    /// </summary>
    private GameObject shot;

    /// <summary>
    /// 拉伸弹弓小鸟的位置
    /// </summary>
    private Vector3 lastKnowPosition;

    private Vector3 direction;
    /// <summary>
    /// [ˈmægnɪtju:d] n. 巨大，广大；重大，重要；量级；（地震）级数 
    /// </summary>
    private float magnitude;

    /// <summary>
    /// 小鸟运动的轨迹线
    /// </summary>
    public static bool isDrawing = false;
    /// <summary>
    /// 小鸟发出去后下一个小鸟是否上弹弓
    /// </summary>
    public static bool isJump = false;
    /// <summary>
    /// 飞出去的小鸟
    /// </summary>
    public static GameObject myBird;
    /// <summary>
    /// 发射的是那只小鸟
    /// </summary>
    public static int birdNumber;
    /// <summary>
    /// 画弹弓的橡皮筋
    /// </summary>
    private LineRenderer lineRenderer;

    private int index = 0;
    private Vector3 position;

    // Use this for initialization
    void Start()
    {
        birdNumber = -1;
        lineRenderer = gameObject.AddComponent<LineRenderer>();//添加对象 画两条线
        lineRenderer.material.color = myColor;
        lineRenderer.SetWidth(0.1f, 0.1f);//设置宽度
        lineRenderer.SetVertexCount(3);//橡皮筋两个点+小鸟一个点 ['vɜ:teks] n. 最高点；顶点；<数>（三角形、圆锥体等与底相对的）顶；（三角形、多边形等的）角的顶点
    }

    // Update is called once per frame
    void Update()
    {
        bool isMouseDown = Input.GetMouseButton(0);
        if (!isClick)//拖放小鸟 没有点击
        {
            if (isMouseDown)
            {
                Ray ray = Camera.main.ScreenPointToRay(Input.mousePosition);//把鼠标的点定义一个射线
                RaycastHit hit;//光线投射碰撞
                if (collider.Raycast(ray, out hit, 10.0f))//光线投射 选择小鸟 [distance光线的长度。]
                {
                    isClick = true;
                    if (birdNumber <= 1)
                    {
                        //Instantiate()克隆原始物体，位置设置在position，设置旋转在rotation，返回的是克隆后的物体
                        //Quaternion.identity：返回恒等式旋转（只读）。这个四元数对于“无旋转”：这个物体完全对齐于世界或父轴。
                        shot = Instantiate(bird, transform.position, Quaternion.identity) as GameObject;//动态的生成被发射的小鸟  [ɪns'tænʃɪeɪt]  实例化 
                        //Physics.IgnoreCollision 忽略碰撞：使碰撞体1和碰撞体2的碰撞侦测无效。
                        Physics.IgnoreCollision(shot.collider, GetComponent<Collider>()); //忽略小鸟碰撞体
                        shot.rigidbody.isKinematic = true;//运动属性
                        myBird = GameObject.FindWithTag("bird0");//拉伸位置的Bird
                        myBird.active = false;//隐藏
                    }
                }
            }
        }
        else if (isMouseDown)
        {
            var lastDirection = direction;
            lastKnowPosition = Camera.main.ScreenToWorldPoint(new Vector3(Input.mousePosition.x, Input.mousePosition.y, 0.8f));
            direction = transform.position - lastKnowPosition;
            direction.Normalize();//规范化当规范化时，一个向量保持相同的方向，但它的长度为1.0。
            magnitude = Mathf.Min(Vector3.Distance(transform.position, lastKnowPosition), 2.5f);//最小值:橡皮筋拉伸距离;返回两个或更多值中最小的值。
            shot.transform.position = transform.position + direction * (-magnitude);
            lineRenderer.enabled = true;//LineRenderer :线渲染器 如果启用，使被渲染的物体可见
            //三点：小鸟+弹弓两点
            lineRenderer.SetPosition(0, new Vector3(-5.1f, 2.2f, 0.1f));//弹弓橡皮筋点
            lineRenderer.SetPosition(1, shot.transform.position);//小鸟点
            lineRenderer.SetPosition(2, new Vector3(-5.6f, 1.2f, -0.1f));//弹弓橡皮筋点
            if (direction != lastDirection)
            {
                if (!audio.isPlaying)
                {
                    PlaySound(slingShotSound);
                }   
                
            }
        }
        else//发射
        {
            birdNumber++;
            if (birdNumber<=2)
            {
                GameObject birdObject2 = GameObject.FindWithTag("birdClone");//实例化的小鸟也就是飞出去的小鸟
                if (birdObject2!=null)
                {
                    Destroy(birdObject2, 1.0f);////加载物体1秒后销毁游戏物体
                }
                lineRenderer.enabled = false;//不显示橡皮筋了
                shot.collider.isTrigger = false;
                shot.rigidbody.isKinematic = false;// 是否动力学：[ˌkɪnɪ'mætɪk] adj. 运动学的，运动学上的
                shot.rigidbody.velocity = direction * 7.0f * magnitude;//速度
                shot.rigidbody.useGravity = true;
                if (audio.isPlaying)
                {
                    audio.Stop();
                }
                PlaySound(flyingSound); 
                shot.tag = "birdClone";
                isClick = false;
            }
        }
    }



    /// <summary>
    /// 小鸟拉伸发生声音
    /// </summary>
    /// <param name="soundName"></param>
    /// <returns></returns>
    public  void PlaySound(AudioClip soundName)
    {
        if (!audio.isPlaying)
        {
            audio.clip = soundName;
            audio.Play(); 
            new WaitForSeconds(audio.clip.length);
        }   
    }
}