AForge.Math.Geometry.SimpleShapeChecker.IsTriangle C# (CSharp) Method

        public bool IsTriangle( List<IntPoint> edgePoints )
        {
            List<IntPoint> corners;
            return IsTriangle( edgePoints, out corners );
        }

        private void ParseImage(int imageId)
        {
            DateTime startTime = DateTime.Now;
            labelDetection.Text = "";

            string difImagePath = "";

            if(imageId >= 0) difImagePath = DifBoardImages[imageId];

            Bitmap orig;
            Bitmap dif;

            try
            {
                orig = (Bitmap)Bitmap.FromFile(OriginalBoardImage);

                if (imageId >= 0)
                    dif = (Bitmap)Bitmap.FromFile(difImagePath);
                else
                    dif = (Bitmap)pictureBoxGenerated.Image;
            }
            catch {
                // kill any exception due to missing files
                return;
            }

            pictureBoxOrig.Image = dif;

            Difference filter = new Difference(orig);
            dif = filter.Apply(dif);

            BlobCounter blobCounter = new BlobCounter();
            blobCounter.ProcessImage(dif);
            Blob[] blobs = blobCounter.GetObjectsInformation();

            // create Graphics object to draw on the image and a pen
            Graphics g = Graphics.FromImage(dif);
            Pen redPen = new Pen(Color.Red, 3);
            Pen bluePen = new Pen(Color.Blue, 1);
            SimpleShapeChecker shapeChecker = new SimpleShapeChecker();
            // check each object and draw circle around objects, which
            // are recognized as circles
            for (int i = 0, n = blobs.Length; i < n; i++)
            {
                List<IntPoint> edgePoints = blobCounter.GetBlobsEdgePoints(blobs[i]);

                labelDetection.Text = string.Format("{0} points", edgePoints.Count);

                if (edgePoints.Count <= 1)
                    continue;

                List<IntPoint> points = new List<IntPoint>();

                if (shapeChecker.IsQuadrilateral(edgePoints))
                    labelDetection.Text += ", quadrilateral";
                else if (shapeChecker.IsConvexPolygon(edgePoints, out points))
                    labelDetection.Text += ", convex poligon";
                else if (shapeChecker.IsTriangle(edgePoints, out points))
                    labelDetection.Text += ", triangle";

                Pen usePen = shapeChecker.IsQuadrilateral(edgePoints) ? redPen : bluePen;

                int centerX = edgePoints[0].X;
                int centerY = edgePoints[0].Y;
                int minX = centerX;
                int minY = centerY;
                int maxX = centerX;
                int maxY = centerY;
                for (int j = 0; j < edgePoints.Count - 1; j++)
                {
                    centerX += edgePoints[j + 1].X;
                    centerY += edgePoints[j + 1].Y;

                    if (edgePoints[j + 1].X < minX) minX = edgePoints[j + 1].X;
                    if (edgePoints[j + 1].Y < minY) minY = edgePoints[j + 1].Y;
                    if (edgePoints[j + 1].X > maxX) maxX = edgePoints[j + 1].X;
                    if (edgePoints[j + 1].Y > maxX) maxX = edgePoints[j + 1].Y;

                    g.DrawLine(usePen, edgePoints[j].X, edgePoints[j].Y, edgePoints[j + 1].X, edgePoints[j + 1].Y);
                }

                g.DrawLine(usePen
                    , edgePoints[0].X, edgePoints[0].Y
                    , edgePoints[edgePoints.Count - 1].X, edgePoints[edgePoints.Count - 1].Y);

                labelDetectedPosition.Text = string.Format("{0}, {1}"
                    , new object[] {
                        (centerX / edgePoints.Count), (centerY / edgePoints.Count)
                        //, maxX - minX, maxY - minY
                    });
                labelDetectionOffset.Text = string.Format("{0}, {1}"
                    , Grigore.Position.X - (centerX / edgePoints.Count)
                    , Grigore.Position.Y - (centerY / edgePoints.Count)
                );
            }

            redPen.Dispose();
            bluePen.Dispose();
            g.Dispose();

            pictureBoxRoboBoard.Image = dif;

            labelDetection.Text = string.Format("{1}, {0} sec", (DateTime.Now - startTime), labelDetection.Text);
        }