Unity UI 羽化出现动画

前情提要：做项目时不时就碰到说要UI从上到下的羽化渐出效果，但好像找插件又没找到这种的，DOTween好像也没这种功能，那只能自己手搓了，但就写多了又觉得烦，干脆点做个小插件吧

下面是效果：

 下面是代码，挂在父物体就能用，不需要添加Mask2D

using System;
using System.Collections;
using Unity.VisualScripting.FullSerializer;
using UnityEngine;
using UnityEngine.UI;

public class Mask2DAnimation : MonoBehaviour
{
    private RectMask2D rectMask2D;
    private RectTransform _rectTransform;
    
    public bool go;
    [Header("羽化大小（Px）")]
    public Vector2Int eclosion; 
    [Header("羽化方向（跟出现方向相反）")]
    public FeatherDirection featherDirection;
    [Header("动画时间")]
    public float animationTime;
    
    void Start()
    {
        _rectTransform = GetComponent<RectTransform>();
        rectMask2D = gameObject.AddComponent<RectMask2D>();
        rectMask2D.softness = eclosion;
        switch (featherDirection)
        {
            case FeatherDirection.Top:
                rectMask2D.padding = new Vector4(0, -eclosion.y, 0, _rectTransform.sizeDelta.y);
                break;
            case FeatherDirection.Bottom:
                rectMask2D.padding = new Vector4(0, _rectTransform.sizeDelta.y, 0, -eclosion.y);
                break;
            case FeatherDirection.Left:
                rectMask2D.padding = new Vector4(_rectTransform.sizeDelta.x, 0, -eclosion.x, 0);
                break;
            case FeatherDirection.Right:
                rectMask2D.padding = new Vector4(-eclosion.x, 0, _rectTransform.sizeDelta.x, 0);
                break;
        }
        // rectMask2D.padding = new Vector4(Left, Bottom, Right, Top);
        StartCoroutine(ControlMask());
    }

    IEnumerator ControlMask()
    {
        while (true)
        {
            float xpx = (_rectTransform.sizeDelta.x + eclosion.x) * Time.deltaTime / animationTime;
            float ypx = (_rectTransform.sizeDelta.y + eclosion.y) * Time.deltaTime / animationTime;
            if (go)
            {
                switch (featherDirection)
                {
                    case FeatherDirection.Top:
                        if (rectMask2D.padding.w > -eclosion.y)
                        {
                            rectMask2D.padding -= new Vector4(0, 0, 0, ypx);
                        }
                        break;
                    case FeatherDirection.Bottom:
                        if (rectMask2D.padding.y > -eclosion.y)
                        {
                            rectMask2D.padding -= new Vector4(0, ypx, 0, 0);
                        }
                        break;
                    case FeatherDirection.Left:
                        if (rectMask2D.padding.x > -eclosion.x)
                        {
                            rectMask2D.padding -= new Vector4(xpx, 0, 0, 0);
                        }
                        break;
                    case FeatherDirection.Right:
                        if (rectMask2D.padding.z > -eclosion.x)
                        {
                            rectMask2D.padding -= new Vector4(0, 0, xpx, 0);
                        }
                        break;
                }
            }
            else
            {
                switch (featherDirection)
                {
                    case FeatherDirection.Top:
                        if (rectMask2D.padding.w < _rectTransform.sizeDelta.y)
                        {
                            rectMask2D.padding += new Vector4(0, 0, 0, ypx);
                        }
                        break;
                    case FeatherDirection.Bottom:
                        if (rectMask2D.padding.y < _rectTransform.sizeDelta.y)
                        {
                            rectMask2D.padding += new Vector4(0, ypx, 0, 0);
                        }
                        break;
                    case FeatherDirection.Left:
                        if (rectMask2D.padding.x < _rectTransform.sizeDelta.x)
                        {
                            rectMask2D.padding += new Vector4(xpx, 0, 0, 0);
                        }
                        break;
                    case FeatherDirection.Right:
                        if (rectMask2D.padding.z < _rectTransform.sizeDelta.x)
                        {
                            rectMask2D.padding += new Vector4(0, 0, xpx, 0);
                        }
                        break;
                }
            }
            yield return null;
        }
    }
}
 
public enum FeatherDirection
{
    Top,
    Bottom,
    Left,
    Right
}