OpenCvSharp で対称定規。 依存関係は OpenCvSharp のみ

対称定規.cs

using System;
using System.Collections.Generic;
using OpenCvSharp.CPlusPlus;
using OpenCvSharp;

namespace OpenCvSharpSomethings
{
    class Program
    {
        static Mat[] rotMat;

        static IEnumerable<IEnumerable<Point>> GetSymmetryLinePoints(Point p1, Point p2, Size imageSize)
        {
            var ox = (imageSize.Width / 2);
            var oy = (imageSize.Height / 2);

            var src1 = new Mat(3, 1, MatType.CV_64FC1, new double[] { p1.X, p1.Y, 1 });
            var src2 = new Mat(3, 1, MatType.CV_64FC1, new double[] { p2.X, p2.Y, 1 });
            var src3 = new Mat(3, 1, MatType.CV_64FC1, new double[] { imageSize.Width - p1.X, p1.Y, 1 });
            var src4 = new Mat(3, 1, MatType.CV_64FC1, new double[] { imageSize.Width - p2.X, p2.Y, 1 });

            var dstPoints = new List<List<Point>>();

            for (int i = 0; i <6; i++)
            {
                Mat m1 = rotMat[i] * src1;
                Mat m2 = rotMat[i] * src2;
                Mat m3 = rotMat[i] * src3;
                Mat m4 = rotMat[i] * src4;
                var points = new List<Point>
                {
                    new Point(m1.At<double>(0), m1.At<double>(1)),
                    new Point(m2.At<double>(0), m2.At<double>(1))
                };
                var points2 = new List<Point>
                {
                    new Point(m3.At<double>(0), m3.At<double>(1)),
                    new Point(m4.At<double>(0), m4.At<double>(1))
                };
                dstPoints.Add(points);
                dstPoints.Add(points2);
            }
            return dstPoints;

        }

        static void Main(string[] args)
        {
            using (var window = new Window("対称定規"))
            {
                const int WindowHeightWidth = 600;
                var ImageSize = new Size(WindowHeightWidth, WindowHeightWidth);
                var BackgroundColor = CvColor.Black;
                var ForegroundColor = CvColor.Aquamarine;
                var previewPoint = new Point(-1, -1);
                var mat = new Mat(ImageSize, MatType.CV_8UC3);
                int Thickness = 1;
                mat.SetTo(BackgroundColor);

                // 回転行列作成
                rotMat = new Mat[6];
                for (int i = 0; i < 6; i++)
                {
                    rotMat[i] = Cv2.GetRotationMatrix2D(new Point2f(ImageSize.Width / 2, ImageSize.Height / 2), i * -60, 1);
                }

                window.ShowImage(mat);

                window.OnMouseCallback += (e, x, y, flags) =>
                {
                    if (e == MouseEvent.MouseMove && flags == MouseEvent.FlagLButton)
                    {
                        var nowPoint = new Point(x, y);
                        if (previewPoint.X != -1)
                        {
                            var points = GetSymmetryLinePoints(previewPoint, nowPoint, ImageSize);
                            mat.Polylines(points, false, ForegroundColor, Thickness, LineType.AntiAlias);
                            previewPoint = nowPoint;
                        }
                        else
                        {
                            mat.Circle(nowPoint, 1, ForegroundColor, Thickness - 1, LineType.AntiAlias);
                            previewPoint = nowPoint;
                        }
                        window.ShowImage(mat);
                    }
                    else if (e == MouseEvent.LButtonUp)
                    {
                        previewPoint = new Point(-1, -1);
                    }
                };

                bool notEscDown = true;
                while (notEscDown)
                {
                    switch (Cv2.WaitKey(1))
                    {
                        case 3014656: //Delete #Clear
                            mat.SetTo(BackgroundColor);
                            window.ShowImage(mat);
                            break;
                        case 27: //Esc #Exit
                            notEscDown = false;
                            break;
                        case 32: //SpaceBar #Save
                            mat.SaveImage(DateTime.Now.ToString("yyyyMMdd-HHmmss") + ".jpg");
                            break;
                        default:
                            break;
                    }
                }
            }
        }
    }
}