using UnityEngine;

using System.Collections;

public class ProjectileTest : MonoBehaviour

{

    public GameObject target;

    public float speed = 10;

    private float distanceToTarget;

    private bool move = true;

    void Start()

    {

        //获取两点之间的距离

        distanceToTarget = Vector3.Distance(this.transform.position, target.transform.position);

        StartCoroutine(Shoot());

    }

    IEnumerator Shoot()

    {

        while (move)

        {

            Vector3 targetPos = target.transform.position;

            this.transform.LookAt(targetPos);

            float angle = Mathf.Min(1, Vector3.Distance(this.transform.position, targetPos) / distanceToTarget) * 45;

            this.transform.rotation = this.transform.rotation * Quaternion.Euler(Mathf.Clamp(-angle, -42, 42), 0, 0);

            //向目标点移动

            float currentDist = Vector3.Distance(this.transform.position, target.transform.position);

            this.transform.Translate(Vector3.forward * Mathf.Min(speed * Time.deltaTime, currentDist));

            //如果距离目标0.5就停止移动

            if (currentDist < 0.5f)

            {

                move = false;

            }

            yield return null;

        }

    }

}