【Unity】查看与显示游戏帧数FPS

FPS是衡量游戏性能的一个重要指标，Unity是跨平台的引擎工具，所以没有统一限定他的帧速率。
在PC平台，一般说来是越高越好，FPS越高，游戏越流畅。
在手机平台，普遍的流畅指标为60帧，能跑到60帧，就是非常流畅的体验了，再高的话一来差别很小，二来帧数太高，会耗费CPU和GPU，会导致发热和耗电量大。

  public class example : MonoBehaviour{    public float updateInterval = 0.5F;    private double lastInterval;    private int frames = 0;    private float fps;    void Start()    {        lastInterval = Time.realtimeSinceStartup;        frames = 0;    }    void OnGUI()    {        GUILayout.Label(" " + fps.ToString("f2"));    }    void Update()    {        ++frames;        float timeNow = Time.realtimeSinceStartup;        if (timeNow > lastInterval + updateInterval)        {            fps = (float)(frames / (timeNow - lastInterval));            frames = 0;            lastInterval = timeNow;        }    }}

using UnityEngine;
using System.Collections;

public class ShowFPS : MonoBehaviour {

    public float f_UpdateInterval = 0.5F;

    private float f_LastInterval;

    private int i_Frames = 0;

    private float f_Fps;

    void Start() 
    {
		//Application.targetFrameRate=60;

        f_LastInterval = Time.realtimeSinceStartup;

        i_Frames = 0;
    }

    void OnGUI() 
    {
        GUI.Label(new Rect(0, 100, 200, 200), "FPS:" + f_Fps.ToString("f2"));
    }

    void Update() 
    {
        ++i_Frames;

        if (Time.realtimeSinceStartup > f_LastInterval + f_UpdateInterval) 
        {
            f_Fps = i_Frames / (Time.realtimeSinceStartup - f_LastInterval);

            i_Frames = 0;

            f_LastInterval = Time.realtimeSinceStartup;
        }
    }
}