Unity2d摄像机自适应

2d游戏开发为了始终让物体在摄像机视野范围内，要保持size的大小为屏幕高度的一半。使用比值法。

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

public class AspectRadio2D : MonoBehaviour
{
    Camera cam;
    public int DesignHalfWidth;  //一半的宽度
    public int DesignHalfHeight; //一半
    public int pixofperunit = 100;
    float designRadio
    {
        get
        {
            return (float)DesignHalfWidth / DesignHalfHeight;
        }
    }
    float realRadio
    {
        get
        {
            return (float)Screen.width / Screen.height;
        }
    }
    void Start()
    {
        cam = transform.GetComponent<Camera>();
    }

    void Update()
    {
        Debug.Log(realRadio);
        if (designRadio<realRadio)
        {
            //当前分辨率大于设计分辨率，unity会自动缩放,加个判断，减少计算量
            cam.orthographicSize = (float)DesignHalfHeight/pixofperunit;
        }
        else
        {
            float radio = designRadio / realRadio;
            cam.orthographicSize = DesignHalfHeight / (radio* pixofperunit);
        }

    }
}