fadein fadeout in unity 游戏大作LOGO渐隐渐出的UNITY实现方法

fadein fadeout in unity 游戏大作LOGO渐隐渐出的UNITY实现方法  

From:  http://cl314413.blog.163.com/blog/static/190507976201192210645452/

using UnityEngine;
using System.Collections;
public class SplashScreen : MonoBehaviour
{
    public string levelToLoad = ""; // this has to correspond to a level (file>build settings)
    public Texture2D splashLogo; // the logo to splash;
    public float fadeSpeed = 0.3f;
    public float waitTime = 0.5f; // seconds to wait before fading out
    public bool waitForInput = false; // if true, this acts as a "press any key to continue"
    private float timeFadingInFinished = 0.0f;
    public enum SplashType
    {
        LoadNextLevelThenFadeOut,
        FadeOutThenLoadNextLevel
    }
    public SplashType splashType;
    private float alpha = 0.0f;
    private enum FadeStatus
    {
        FadeIn,
        FadeWaiting,
        FadeOut
    }
    private FadeStatus status = FadeStatus.FadeIn;
    private Camera oldCam;
    private GameObject oldCamGO;
    private Rect splashLogoPos = new Rect();
    public enum LogoPositioning
    {
        Centered,
        Stretched
    }
    public LogoPositioning logoPositioning;
    private bool loadingNextLevel = false;
    void Start()
    {
        oldCam = Camera.main;
        oldCamGO = Camera.main.gameObject;
        if (logoPositioning == LogoPositioning.Centered)
        {
            splashLogoPos.x = (Screen.width * 0.5f) - (splashLogo.width * 0.5f);
            splashLogoPos.y = (Screen.height * 0.5f) - (splashLogo.height * 0.5f);
       
            splashLogoPos.width = splashLogo.width;
            splashLogoPos.height = splashLogo.height;
        }
        else
        {
            splashLogoPos.x = 0;
            splashLogoPos.y = 0;
           
            splashLogoPos.width = Screen.width;
            splashLogoPos.height = Screen.height;
        }
       
      
        if (splashType == SplashType.LoadNextLevelThenFadeOut)
        {
            DontDestroyOnLoad(this);
            DontDestroyOnLoad(Camera.main);
        }
        if ((Application.levelCount <= 1) || (levelToLoad == ""))
        {
            Debug.Log("I need to have a level to load or the value of level To load is wrong!");
            return;
        }
    }
    void Update()
    {
        switch(status)
        {
            case FadeStatus.FadeIn:
                alpha += fadeSpeed * Time.deltaTime;
            break;
            case FadeStatus.FadeWaiting:
                if ((!waitForInput && Time.time >= timeFadingInFinished + waitTime) || (waitForInput && Input.anyKey))
                {
                    status = FadeStatus.FadeOut;
                }
            break;
            case FadeStatus.FadeOut:
                alpha += -fadeSpeed * Time.deltaTime;
            break;
        }
    }
    void OnGUI()
    {
        if (splashLogo != null)
        {
            GUI.color = new Color(GUI.color.r, GUI.color.g, GUI.color.b, Mathf.Clamp01(alpha));
            GUI.DrawTexture(splashLogoPos, splashLogo);
            if (alpha > 1.0f)
            {
                status = FadeStatus.FadeWaiting;
                timeFadingInFinished = Time.time;
                alpha = 1.0f;
                if (splashType == SplashType.LoadNextLevelThenFadeOut)
                {
                    oldCam.depth = -1000;
                    loadingNextLevel = true;
                    Application.LoadLevel(levelToLoad);
                }
            }
            if (alpha < 0.0f)
            {
                if (splashType == SplashType.FadeOutThenLoadNextLevel)
                {
                    Application.LoadLevel(levelToLoad);
                }
                else
                {
                    Destroy(oldCamGO); // somehow this doesn't work
                    Destroy(this);
                }
            }
        }
    }
    void OnLevelWasLoaded(int lvlIdx)
    {
        if (loadingNextLevel)
        {
            Destroy(oldCam.GetComponent<AudioListener>());
            Destroy(oldCam.GetComponent<GUILayer>());
        }
    }
    void OnDrawGizmos()
    {
        Gizmos.color = new Color(1f, 0f, 0f, .5f);
        Gizmos.DrawCube(transform.position, new Vector3(1, 1, 1));
    }
}