loading条顺滑加载

大部分代码参考了

http://www.58player.com/blog-2537-89690.html

不过，它的逻辑有地方不太严谨，对比一下即可。

    /// 

    /// 异步加载场景
    /// 
	public void LoadScene()
	{
		if(!string.IsNullOrEmpty(loadScenePath))
		{
            StartCoroutine(loadScenceAsyn());
		}
	}

    /// 

    /// 加载速度
    /// 
    public int LoadSpeed = 1;

    private IEnumerator loadScenceAsyn()
    {
        
        asynOp = Application.LoadLevelAsync(loadScenePath);

        if (show == false || asynOp == null)
        {
            yield break;
        }

        int displayProgress = 0;
        int toProgress = 0;

        asynOp.allowSceneActivation = false;

        while (asynOp.progress < 0.9f)
        {
            toProgress = (int)(asynOp.progress * 100);
            while (displayProgress < toProgress)
            {
                displayProgress += LoadSpeed;
                SetProgressBarValue(displayProgress);
                yield return new WaitForEndOfFrame();
            }
            yield return new WaitForEndOfFrame();
        }

        toProgress = 100;
        while (displayProgress < toProgress)
        {
            displayProgress += LoadSpeed;
            SetProgressBarValue(displayProgress);
            yield return new WaitForEndOfFrame();
        }

        asynOp.allowSceneActivation = true;
        
        while (!asynOp.isDone)
        {
            yield return new WaitForEndOfFrame();
        }

        StartDelyHideLoadingUI();
        
    }