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

//红外线瞄准器的设定
//射线射到的地方会出现红点
public class LaserItem : MonoBehaviour {
    public GameObject hitImg;
    RaycastHit laserHit;
    public float rayDown;

	// Use this for initialization
	void Start () {
		
	}
	
	// Update is called once per frame
	void Update () {
        if (Physics.Raycast(gameObject.transform.position + gameObject.transform.forward * 0.2f - gameObject.transform.up * rayDown, gameObject.transform.forward, out laserHit, 10000))
        {
            DrawPoint(laserHit);
        }
    }

    public void DrawPoint(RaycastHit Hit_loaded)
    {
        hitImg.transform.position = new Vector3(Hit_loaded.point.x, Hit_loaded.point.y, Hit_loaded.point.z);
        //Clamp强制取区间的数值，如果不在区间内则取最大/最小值
        float angle_x = Mathf.Acos(Mathf.Clamp(Hit_loaded.normal.x, -1f, 1f)) * 180 / Mathf.PI - 90.0f;
        float angle_y = Mathf.Asin(Mathf.Clamp(Hit_loaded.normal.y, -1f, 1f)) * 180 / Mathf.PI;
        if (Hit_loaded.normal.z > 0.0f)
        {
            angle_x = 180 - angle_x;
        }
        //print(new Vector3(angle_y, angle_x, 0.0f));
        if (hitImg.transform.eulerAngles.y != 0f)
        {
            hitImg.transform.eulerAngles += new Vector3(-angle_y, angle_x, 0.0f);
        }
        else
        {
            hitImg.transform.eulerAngles += new Vector3(angle_y, angle_x, 0.0f);
        }
    }
}