using System.Collections;
using System.Collections.Generic;
using UnityEngine;
public class Test01 : MonoBehaviour
{
    Transform cam;//相机物体
    Vector3 pos;
    // Start is called before the first frame update
    void Start()
    {
        pos = transform.position;
        cam = GameObject.FindWithTag("MainCamera").transform;
    }
    // Update is called once per frame
    void Update()
    {
        Vector3 offset = pos - cam.position;//相对相机的偏移位置
        Vector3 camSize = new Vector3(1.51f*(1920f/1080f)-0.2f, 1.51f-0.2f,0);//相机的宽度和高度的一半尺寸，这里假设相机的高度一半为1.51
        camSize = camSize - new Vector3(0.2f, 0.2f, 0);//在坐标在屏幕外时，让自己在屏幕内离边缘一段距离0.2
        //判断是在屏幕内还是屏幕外
        bool isInCam = (Mathf.Abs(offset.x) < camSize.x) && (Mathf.Abs(offset.y) < camSize.y);
        //如果是在屏幕内，那么坐标位置等于自己的坐标位置
        //如果是在屏幕外，那么坐标位置在屏幕边缘
        if (isInCam) {
            transform.position = pos;
        }
        else {
            float x=pos.x;
            if (Mathf.Abs(offset.x) > camSize.x) x = Mathf.Sign(offset.x) * camSize.x + cam.position.x;
            //x = x + -Mathf.Sign(offset.x) * 0.2f;
 
            float y = pos.y;
            if (Mathf.Abs(offset.y) > camSize.y) y = Mathf.Sign(offset.y) * camSize.y + cam.position.y;
            //y = y + -Mathf.Sign(offset.y) * 0.2f;
            transform.position =new Vector3(x, y, 0);
        }
    }
    //判断是在屏幕内还是屏幕外
    //如果是在屏幕内，那么坐标位置等于自己的坐标位置
    //如果是在屏幕外，那么坐标位置在屏幕边缘
 
    private void OnDrawGizmos()
    {
        //Gizmos.color = Color.red;
        //float x = 1920f / 1080f;
        //Gizmos.DrawCube(transform.position, new Vector3(1.51f * (1920f / 1080f), 1.51f, 0) * 2);
    }
}