Unity 利用像素点在图片上画线（RawImage）_unity 利用像素点在图片上画线(rawimage)-CSDN博客文章浏览阅读5.4k次，点赞9次，收藏20次。原理：创建透明度为0的Texture2D,利用改变像素点的颜色，实现画线功能。创建图片rawimage 的大小一定要与屏幕大小保持一致代码部分：完整代码：挂载RawImage上，对应组件拖进去就行/******************************************************************** 作者: # maki #..._unity 利用像素点在图片上画线(rawimage)
https://blog.csdn.net/qq_40120946/article/details/100555786
实现
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.EventSystems;
using UnityEngine.UI;
public class MonoTextureLineTool : MonoBehaviour
{
#region 画线设置
/// <summary>
/// 画线风格
/// </summary>
[SerializeField]
private TextureLineType lineType;//画线风格
/// <summary>
/// 渲染次数：点画线1000，曲线100 不可过大，太消耗渲染性能
/// </summary>
[SerializeField]
private float lineNum = 100f;
/// <summary>
/// 笔刷的宽度
/// </summary>
[SerializeField]
private int lineWidth = 13;
/// <summary>
/// 笔刷的颜色
/// </summary>
[SerializeField]
public Color lineColor = new Color(1, 1, 1, 0.5f);
#endregion
/// <summary>
/// 被操作的贴图
/// </summary>
[SerializeField]
private Texture2D targetTexture;
/// <summary>
/// 目标图片UI
/// </summary>
[SerializeField]
private RawImage targetRawImage;
/// <summary>
/// 划线相机
/// </summary>
[SerializeField]
private Camera lineCamera;
/// <summary>
/// 擦除鼠标图片跟随
/// </summary>
[SerializeField]
public Image mouseImage;
/// <summary>
/// 上一个点鼠标点
/// </summary>
Vector2 lastPoint = Vector2.zero;
/// <summary>
/// 被记录的鼠标位置
/// </summary>
private List<Vector2> mousePoints;
/// <summary>
/// 被记录的步骤
/// </summary>
private List<Texture2D> textureRecords;
/// <summary>
/// 当前画板下标
/// </summary>
int index = 0;
private void Start()
{
lineType = TextureLineType.line;
mousePoints = new List<Vector2>();
lineCamera = Camera.main;
targetRawImage = GetComponent<RawImage>();
targetRawImage.texture = new Texture2D(Screen.width, Screen.height);
targetTexture = targetRawImage.texture as Texture2D;
ClearTexture();
textureRecords = new List<Texture2D>();
RecortStep();
}
void Update()
{
if (lineType == TextureLineType.line || lineType == TextureLineType.eraseLine)
{
if (Input.GetMouseButton(0))
{
if (IsPointerOverUI(targetRawImage.transform))
{
Vector2 addPoint = lineCamera.ScreenToViewportPoint(Input.mousePosition);
OperateTexture(addPoint, lineType);
}
else
{
lastPoint = Vector2.zero;
}
}
if (Input.GetMouseButtonUp(0))
{
lastPoint = Vector2.zero;
RecortStep();
if (mouseImage != null)
{
mouseImage.transform.localPosition = new Vector2(-10000, -10000);
}
}
}
else if (lineType == TextureLineType.dotLine)
{
if (Input.GetMouseButtonDown(0))
{
if (IsPointerOverUI(targetRawImage.transform))
{
Vector2 addPoint = lineCamera.ScreenToViewportPoint(Input.mousePosition);
OperateTexture(addPoint, lineType);
}
else
{
lastPoint = Vector2.zero;
}
}
}
if (Input.GetMouseButtonDown(1))
{
lastPoint = Vector2.zero;
lineType = TextureLineType.none;
}
}
/// <summary>
/// 画线
/// </summary>
/// <param name="point"></param>
/// <param name="mColor"></param>
private void OperateTexture(Vector2 point, TextureLineType lineType)
{
if (lastPoint == Vector2.zero)
{
lastPoint = point;
return;
}
for (int j = 0; j < lineNum; j++)
{
float scaleX = Mathf.Lerp(lastPoint.x, point.x, j / lineNum);
float scaleY = Mathf.Lerp(lastPoint.y, point.y, j / lineNum);
int textureX = (int)(scaleX * Screen.width);
int textureY = (int)(scaleY * Screen.height);
// 线条加粗
for (int a = textureX - lineWidth; a < textureX + lineWidth; a++)
{
for (int b = textureY - lineWidth; b < textureY + lineWidth; b++)
{
targetTexture.SetPixel(a, b, lineColor);
}
}
}
targetTexture.Apply();
lastPoint = point;
if (lineType == TextureLineType.dotLine)
RecortStep();
else if (lineType == TextureLineType.eraseLine)
{
Vector2 pos;
if (RectTransformUtility.ScreenPointToLocalPointInRectangle(this.transform as RectTransform, Input.mousePosition, lineCamera, out pos))
{
mouseImage.transform.localPosition = pos;
}
}
}
/// <summary>
/// 重置贴图(全部擦除)
/// </summary>
public void ClearTexture()
{
int x, y;
for (x = 0; x < targetTexture.width; x++)
{
for (y = 0; y < targetTexture.height; y++)
{
targetTexture.SetPixel(x, y, new Color(1, 1, 1, 0));
}
}
targetTexture.Apply();
}
/// <summary>
/// 设置画线模式
/// </summary>
public void SetLineType(TextureLineType type)
{
lastPoint = Vector2.zero;
lineType = type;
switch (lineType)
{
case TextureLineType.none:
break;
case TextureLineType.line:
lineNum = 100f;
lineWidth = 3;//设置笔宽
lineColor = Color.red;
break;
case TextureLineType.dotLine:
lineNum = 1000f;
lineWidth = 3;//设置笔宽
lineColor = Color.red;
break;
case TextureLineType.eraseLine:
lineNum = 200f;
lineWidth = 30;//设置笔宽
lineColor = new Color(1, 1, 1, 0);
break;
default:
break;
}
}
/// <summary>
/// 记录步骤
/// </summary>
private void RecortStep()
{
if (textureRecords.Count > 0)
{
if (index != textureRecords.Count - 1)
{
textureRecords.RemoveRange((index + 1), textureRecords.Count - (index + 1));
}
}
Texture2D newTexture = Instantiate(targetTexture);
textureRecords.Add(newTexture);
index = textureRecords.Count - 1;
}
/// <summary>
/// 上一步
/// </summary>
public void StepUp()
{
if (index > 0)
{
index--;
targetTexture = Instantiate(textureRecords[index]);
targetRawImage.texture = targetTexture;
}
}
/// <summary>
/// 下一步
/// </summary>
public void StepDown()
{
if (index < textureRecords.Count - 1)
{
index++;
targetTexture = Instantiate(textureRecords[index]);
targetRawImage.texture = targetTexture;
}
}
/// <summary>
/// 获取当前UI
/// </summary>
private bool IsPointerOverUI(Transform tran)
{
if (EventSystem.current.IsPointerOverGameObject())
{
PointerEventData pointerEventData = new PointerEventData(EventSystem.current);
pointerEventData.position = Input.mousePosition;
List<RaycastResult> result = new List<RaycastResult>();
EventSystem.current.RaycastAll(pointerEventData, result);
if (result.Count > 0)
foreach (var item in result)
{
if (item.gameObject.transform.IsChildOf(tran))
{
return true;
}
}
}
return false;
}
}
public enum TextureLineType
{
none,//不画线
line,//自由线
dotLine,//点画线
eraseLine,//擦除线
}
效果
