using UnityEngine;
using UnityEngine.UI;//注意添加RawImage命名空间

public class FadeInOut : MonoBehaviour
{
    [HideInInspector]
    public bool isBlack = false;//不透明状态

    private float fadeSpeed = 5f;//透明度变化速率
    public RawImage rawImage;
    public RectTransform rectTransform;

    private AsyncLoadingScene asyncLoading;
    void Start()
    {
        rawImage.gameObject.SetActive(true);
        rectTransform.sizeDelta = new Vector2(Screen.width, Screen.height);//使背景满屏
        rawImage.color = Color.clear;
        OpenImage(false);
    }

    void Update()
    {

        if (isBlack)
        {
            rawImage.color = Color.Lerp(rawImage.color, Color.black, Time.deltaTime * fadeSpeed);//渐暗
            if (rawImage.color.a > 0.98f)
            {
                rawImage.color = Color.black;
                if (asyncLoading)
                    asyncLoading.canLoad = true;
                else
                    transform.GetComponent<AsyncLoadingScene>().canLoad = true;
            }
        }
        else
        {
            rawImage.color = Color.Lerp(rawImage.color, Color.clear, Time.deltaTime * fadeSpeed * 0.5f);//渐亮

            if (rawImage.color.a < 0.05f)
            {
                rawImage.color = Color.clear;
                rawImage.gameObject.SetActive(false);
            }
        }
        
    }

    public void OpenImage(bool isOpen,AsyncLoadingScene async = null)
    {
        rawImage.gameObject.SetActive(true);
        isBlack = isOpen;
        asyncLoading = async;
    }
}