unity实现抽奖刮刮乐效果

最终效果

代码部分

using DG.Tweening;
using System;
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.EventSystems;
using UnityEngine.UI;

public class ScratchTest : MonoBehaviour, IPointerDownHandler, IDragHandler, IPointerUpHandler
{
    //是否擦除了
    public bool isStartEraser;
    //是否擦除结束了
    public bool isEndEraser;
    //开始事件
    public Action eraserStartEvent;
    //结束事件
    public Action eraserEndEvent;
    public RawImage uiTex;
    Texture2D tex;
    Texture2D MyTex;
    int mWidth;
    int mHeight;
    [Header("笔刷大小")]
    public int brushSize = 50;
    [Header("刮刮乐比例")]
    public int rate = 90;
    float maxColorA;
    float colorA;
    void Awake()
    {
        tex = (Texture2D)uiTex.mainTexture;
        MyTex = new Texture2D(tex.width, tex.height, TextureFormat.ARGB32, false);
        mWidth = MyTex.width;
        mHeight = MyTex.height;
        MyTex.SetPixels(tex.GetPixels());
        MyTex.Apply();
        uiTex.texture = MyTex;
        maxColorA = MyTex.GetPixels().Length;
        colorA = 0;
        isEndEraser = false;
        isStartEraser = false;
    }
    /// 
    /// 贝塞尔平滑
    /// 
    /// 起点
    /// 中点
    /// 终点
    /// 段数
    /// 
    public Vector2[] Beizier(Vector2 start, Vector2 mid, Vector2 end, int segments)
    {
        float d = 1f / segments;
        Vector2[] points = new Vector2[segments - 1];
        for (int i = 0; i  distance)//如果两次记录的鼠标坐标距离大于一定的距离，开始记录鼠标的点
        {
            Vector2 pos = eventData.position;
            float dis = Vector2.Distance(lastPos, pos);

            CheckPoint(eventData.position);
            int segments = (int)(dis / radius);//计算出平滑的段数                                              
            segments = segments = 10) { segments = 10; }
            Vector2[] points = Beizier(penultPos, lastPos, pos, segments);//进行贝塞尔平滑
            for (int i = 0; i  2)
                penultPos = points[points.Length - 2];
        }
        else
        {
            twoPoints = true;
            lastPos = eventData.position;
        }
    }

    public void OnPointerUp(PointerEventData eventData)
    {
        if (isEndEraser) { return; }
        //CheckPoint(eventData.position);
        startDraw = false;
        twoPoints = false;
    }


    #endregion
    void CheckPoint(Vector3 pScreenPos)
    {
        Vector3 worldPos = Camera.main.ScreenToWorldPoint(pScreenPos);
        Vector3 localPos = uiTex.gameObject.transform.InverseTransformPoint(worldPos);

        if (localPos.x > -mWidth / 2 && localPos.x  -mHeight / 2 && localPos.y