如何在图形上创建镜像形状

Question

我有积分表

List<Point> pointList = new List<Point>();

pointList.Add(new Point(0,0));

pointList.Add(new Point(30,0));

pointList.Add(new Point(30,-100));

pointList.Add(new Point(0,-100));

然后画线

Pen pen = new Pen(Color.Red,2);

g.Drawline(pen,pointList[0],pointList[1]);

g.Drawline(pen,pointList[3],poin,tList[4]);

为此，我将在链接中获得左侧图像的结果

如果我需要创建镜像以获得链接中正确图像的结果

有什么方法可以反映我从 pointlist 绘制的图形吗？

它有像复制和翻转图形和复合的东西吗？

谢谢

Answer 1

有了GraphicsPath，您可以使用以下方法来镜像路径：GraphicsPath MirrorLeft(GraphicsPath path){&nbsp; &nbsp; var r = path.GetBounds();&nbsp; &nbsp; var p = (GraphicsPath)path.Clone();&nbsp; &nbsp; p.Transform(new Matrix(-1, 0, 0, 1, 2 * r.Left, 0));&nbsp; &nbsp; return p;}GraphicsPath MirrorRight(GraphicsPath path){&nbsp; &nbsp; var r = path.GetBounds();&nbsp; &nbsp; var p = (GraphicsPath)path.Clone();&nbsp; &nbsp; p.Transform(new Matrix(-1, 0, 0, 1, 2 * (r.Left + r.Width), 0));&nbsp; &nbsp; return p;}MirrorLeft，以路径左侧为轴镜像路径，以路径MirrorRight右侧为轴。下图中，红色弧线为原图，绿色为左镜，蓝色为镜右：这里是上面输出的代码：protected override void OnPaint(PaintEventArgs e){&nbsp; &nbsp; e.Graphics.SmoothingMode = SmoothingMode.AntiAlias;&nbsp; &nbsp; using (var path1 = new GraphicsPath())&nbsp; &nbsp; {&nbsp; &nbsp; &nbsp; &nbsp; path1.AddArc(new Rectangle(100, 100, 200, 200), -90, 90);&nbsp; &nbsp; &nbsp; &nbsp; using (var pen1 = new Pen(Color.Red, 3))&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; e.Graphics.DrawPath(pen1, path1);&nbsp; &nbsp; &nbsp; &nbsp; using (var path2 = MirrorLeft(path1))&nbsp; &nbsp; &nbsp; &nbsp; using (var pen2 = new Pen(Color.Green, 3))&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; e.Graphics.DrawPath(pen2, path2);&nbsp; &nbsp; &nbsp; &nbsp; using (var path3 = MirrorRight(path1))&nbsp; &nbsp; &nbsp; &nbsp; using (var pen3 = new Pen(Color.Blue, 3))&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; e.Graphics.DrawPath(pen3, path3);&nbsp; &nbsp; }&nbsp; &nbsp; base.OnPaint(e);}

Answer 2

您可以简单地翻转Graphics对象：e.Graphics.DrawLines(Pens.Black, pointList.ToArray());e.Graphics.ScaleTransform(-1, 1);// you need to know at which x value the flipping axis should be!e.Graphics.TranslateTransform(..., 0);e.Graphics.DrawLines(Pens.Red, pointList.ToArray());请注意，您需要知道要翻转的位置（镜像轴）。对于您显示的效果，您需要向右移动图形左边缘（最小值）的两倍..：int xmin = pointList.Min(x => x.X);int xmax = pointList.Max(x => x.X);e.Graphics.TranslateTransform(xmin * 2, 0);另请注意，除非您相应地移动 Graphics 对象，否则Graphics只能显示正值。所以没有TranslateTransform你的数字将永远不会显示。（我已经为演示更改了它们。）另请注意，应始终绘制连接Graphics.DrawLines线，否则连接将因笔宽较大和/或半透明颜色而变得混乱。正如 Jimi 所指出的，如果您想继续绘图，您将需要e.Graphics.ResetTransform();在翻转之后执行 a，或者，如果您已经通过将画布转换为正域来准备整个绘图，则恢复它在翻转之前的状态。对于第一个存储状态：var&nbsp;state&nbsp;=&nbsp;e.Graphics.Save();然后恢复它：e.Graphics.Restore(state);请注意，您需要注意这两个命令需要一对一匹配！