Unity签名(一) 书写

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软件主要代码注释解读

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导航

• Go
• 前言
• 一、实现了哪些功能？
• 二、项目环境

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前言

注意:接下来的关于签名插件的书写、重写、更换笔体等功能均来自未知来源的插件，本章就是对源代码的学习

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提示：以下是本篇文章正文内容，下面案例可供参考

一、实现了哪些功能？

基础功能：书写+重写+保存
扩展功能：重放+撤回+显示

二、项目环境

Unity-2018.3.8f1

1、导入插件：

2、找到Signature场景双击运行可看效果

3、查看主要代码 Painting.cs

4、变量参数

BgRawImage：字的背景图片，也就是图中粉色的BG；
TexRender ：是指画布，也就是签名将签在这上面；后面的保存会用到这个组；
MaterialTemp：写字用到的材质球；
BrushTypeTexture：笔刷的样式，决定于不同的Texture；
Text：是用来更新显示保存成功；
BrushColor：笔刷颜色；
Raw:撤回是需要显示的图片；
Num:笔刷的密度；
RawRoot：保存后显示的图片

5、主要代码实现–通过2阶贝塞尔曲线和3阶贝塞尔曲线来实现毛笔的效果

  /// <summary>
    /// 二阶贝塞尔曲线
    /// </summary>
    /// <param name="pos"></param>
    /// <param name="distance"></param>
    public void TwoOrderBézierCurse(Vector3 pos, float distance)
    {
        PositionArray[a] = pos;
        a++;
        if (a == 3)
        {
            for (int index = 0; index < num; index++)
            {
                Vector3 middle = (PositionArray[0] + PositionArray[2]) / 2;
                PositionArray[1] = (PositionArray[1] - middle) / 2 + middle;

                float t = (1.0f / num) * index / 2;
                Vector3 target = Mathf.Pow(1 - t, 2) * PositionArray[0] + 2 * (1 - t) * t * PositionArray[1] +
                                 Mathf.Pow(t, 2) * PositionArray[2];
                float deltaSpeed = (float)(distance - lastDistance) / num;
                DrawBrush(texRender, (int)target.x, (int)target.y, brushTypeTexture, brushColor, SetScale(lastDistance + (deltaSpeed * index)));
            }
            PositionArray[0] = PositionArray[1];
            PositionArray[1] = PositionArray[2];
            a = 2;
        }
        else
        {
            DrawBrush(texRender, (int)endPosition.x, (int)endPosition.y, brushTypeTexture,
                brushColor, brushScale);
        }
    }

    /// <summary>
    /// 三阶贝塞尔曲线，获取连续4个点坐标，通过调整中间2点坐标，画出部分（我使用了num/1.5实现画出部分曲线）来使曲线平滑;通过速度控制曲线宽度。
    /// </summary>
    /// <param name="pos"></param>
    /// <param name="distance"></param>
    /// <param name="targetPosOffset"></param>
    private void ThreeOrderBézierCurse(Vector3 pos, float distance, float targetPosOffset)
    {
        //记录坐标
        PositionArray1[b] = pos;
        b++;
        //记录速度
        speedArray[s] = distance;
        s++;
        if (b == 4)
        {
            Vector3 temp1 = PositionArray1[1];
            Vector3 temp2 = PositionArray1[2];

            //修改中间两点坐标
            Vector3 middle = (PositionArray1[0] + PositionArray1[2]) / 2;
            PositionArray1[1] = (PositionArray1[1] - middle) * 1.5f + middle;
            middle = (temp1 + PositionArray1[3]) / 2;
            PositionArray1[2] = (PositionArray1[2] - middle) * 2.1f + middle;

            for (int index1 = 0; index1 < num / 1.5f; index1++)
            {
                float t1 = (1.0f / num) * index1;
                Vector3 target = Mathf.Pow(1 - t1, 3) * PositionArray1[0] +
                                 3 * PositionArray1[1] * t1 * Mathf.Pow(1 - t1, 2) +
                                 3 * PositionArray1[2] * t1 * t1 * (1 - t1) + PositionArray1[3] * Mathf.Pow(t1, 3);
                //float deltaspeed = (float)(distance - lastDistance) / num;
                //获取速度差值（存在问题，参考）
                float deltaspeed = (float)(speedArray[3] - speedArray[0]) / num;
                //float randomOffset = Random.Range(-1/(speedArray[0] + (deltaspeed * index1)), 1 / (speedArray[0] + (deltaspeed * index1)));
                //模拟毛刺效果
                float randomOffset = Random.Range(-targetPosOffset, targetPosOffset);
                DrawBrush(texRender, (int)(target.x + randomOffset), (int)(target.y + randomOffset), brushTypeTexture, brushColor, SetScale(speedArray[0] + (deltaspeed * index1)));
            }

            PositionArray1[0] = temp1;
            PositionArray1[1] = temp2;
            PositionArray1[2] = PositionArray1[3];

            speedArray[0] = speedArray[1];
            speedArray[1] = speedArray[2];
            speedArray[2] = speedArray[3];
            b = 3;
            s = 3;
        }
        else
        {
            DrawBrush(texRender, (int)endPosition.x, (int)endPosition.y, brushTypeTexture,
                brushColor, brushScale);
        }
    }

6、将上面计算好的坐标点利用DrawBrush()函数，实现显示

 void DrawBrush(RenderTexture destTexture, int x, int y, Texture sourceTexture, Color color, float scale)
    {
        DrawBrush(destTexture, new Rect(x, y, sourceTexture.width, sourceTexture.height), sourceTexture, color, scale);
    }

    void DrawBrush(RenderTexture destTexture, Rect destRect, Texture sourceTexture, Color color, float scale)
    {
        float left = destRect.xMin - destRect.width * scale / 2.0f;
        float right = destRect.xMin + destRect.width * scale / 2.0f;
        float top = destRect.yMin - destRect.height * scale / 2.0f;
        float bottom = destRect.yMin + destRect.height * scale / 2.0f;

        Graphics.SetRenderTarget(destTexture);

        GL.PushMatrix();
        GL.LoadOrtho();

        materialTemp.SetTexture("_MainTex", brushTypeTexture);
        materialTemp.SetColor("_Color", color);
        materialTemp.SetPass(0);

        GL.Begin(GL.QUADS);

        GL.TexCoord2(0.0f, 0.0f); GL.Vertex3(left / Screen.width, top / Screen.height, 0);
        GL.TexCoord2(1.0f, 0.0f); GL.Vertex3(right / Screen.width, top / Screen.height, 0);
        GL.TexCoord2(1.0f, 1.0f); GL.Vertex3(right / Screen.width, bottom / Screen.height, 0);
        GL.TexCoord2(0.0f, 1.0f); GL.Vertex3(left / Screen.width, bottom / Screen.height, 0);

        GL.End();
        GL.PopMatrix();
    }

7、画布的清除功能

    /// <summary>
    /// 重绘
    /// </summary>
    /// <param name="destTexture"></param>
    void Clear(RenderTexture destTexture)
    {
        Graphics.SetRenderTarget(destTexture);
        GL.PushMatrix();
        //GL.Clear(true, true, Color.white);
        GL.Clear(true, true, new Color(0f, 0f, 1f, 0f));
        GL.PopMatrix();
        texRender = new RenderTexture(Screen.width / 2, Screen.height / 2, 24, RenderTextureFormat.ARGB32);
    }

结：基础功能完事儿----->下一站Unity签名（二）重放+撤销