final effect
code section
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;
}
/// <summary>
/// 贝塞尔平滑
/// </summary>
/// <param name="start">起点</param>
/// <param name="mid">中点</param>
/// <param name="end">终点</param>
/// <param name="segments">段数</param>
/// <returns></returns>
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 < points.Length; i++)
{
float t = d * (i + 1);
points[i] = (1 - t) * (1 - t) * mid + 2 * t * (1 - t) * start + t * t * end;
}
List<Vector2> rps = new List<Vector2>();
rps.Add(mid);
rps.AddRange(points);
rps.Add(end);
return rps.ToArray();
}
bool startDraw = false;
bool twoPoints = false;
Vector2 lastPos;//最后一个点
Vector2 penultPos;//倒数第二个点
float radius = 12f;
float distance = 1f;
#region 事件
public void OnPointerDown(PointerEventData eventData)
{
if (isEndEraser) {
return; }
startDraw = true;
penultPos = eventData.position;
CheckPoint(penultPos);
}
public void OnDrag(PointerEventData eventData)
{
if (isEndEraser) {
return; }
if (twoPoints && Vector2.Distance(eventData.position, lastPos) > 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 < 1 ? 1 : segments;
if (segments >= 10) {
segments = 10; }
Vector2[] points = Beizier(penultPos, lastPos, pos, segments);//进行贝塞尔平滑
for (int i = 0; i < points.Length; i++)
{
CheckPoint(points[i]);
}
lastPos = pos;
if (points.Length > 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 < mWidth / 2 && localPos.y > -mHeight / 2 && localPos.y < mHeight / 2)
{
for (int i = (int)localPos.x - brushSize; i < (int)localPos.x + brushSize; i++)
{
for (int j = (int)localPos.y - brushSize; j < (int)localPos.y + brushSize; j++)
{
if (Mathf.Pow(i - localPos.x, 2) + Mathf.Pow(j - localPos.y, 2) > Mathf.Pow(brushSize, 2))
continue;
if (i < 0) {
if (i < -mWidth / 2) {
continue; } }
if (i > 0) {
if (i > mWidth / 2) {
continue; } }
if (j < 0) {
if (j < -mHeight / 2) {
continue; } }
if (j > 0) {
if (j > mHeight / 2) {
continue; } }
Color col = MyTex.GetPixel(i + (int)mWidth / 2, j + (int)mHeight / 2);
if (col.a != 0f)
{
col.a = 0.0f;
colorA++;
MyTex.SetPixel(i + (int)mWidth / 2, j + (int)mHeight / 2, col);
}
}
}
//开始刮的时候 去判断进度
if (!isStartEraser)
{
isStartEraser = true;
InvokeRepeating("getTransparentPercent", 0f, 0.2f);
if (eraserStartEvent != null)
eraserStartEvent.Invoke();
}
MyTex.Apply();
}
}
double fate;
/// <summary>
/// 检测当前刮刮卡 进度
/// </summary>
/// <returns></returns>
public void getTransparentPercent()
{
if (isEndEraser) {
return; }
fate = colorA / maxColorA * 100;
fate = (float)Math.Round(fate, 2);
//Debug.Log("当前百分比: " + fate);
if (fate >= rate)
{
isEndEraser = true;
CancelInvoke("getTransparentPercent");
uiTex.gameObject.SetActive(false);
//触发结束事件
if (eraserEndEvent != null)
eraserEndEvent.Invoke();
}
}
}
Use the method
Canvas to set to Screen Space-Camera and specify the UI camera.
Prepare a base image and the image to be scratched, the base image is Image, and the image to be scratched is RawImage. (Note that the picture should not be deformed in the aspect ratio, it can be scaled proportionally, otherwise it will affect the scratch marks and judgment)
Hang the script under the Canvas and drag the RawImage to UiTex.
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