AForge.Point.SquaredDistanceTo C# (CSharp) Method

        public float SquaredDistanceTo( Point anotherPoint )
        {
            float dx = X - anotherPoint.X;
            float dy = Y - anotherPoint.Y;

            return dx * dx + dy * dy;
        }

        public Bitmap ProcessFrame(Bitmap frame)
        {
            var filter = new EuclideanColorFiltering();

            filter.CenterColor = _color;
            filter.Radius      = 20;
            filter.ApplyInPlace(frame);

            //var filter = new Grayscale(0.2125, 0.7154, 0.0721);
            //var thresh = new Threshold(thresh_val);
            //frame = filter.Apply(frame);
            //thresh.ApplyInPlace(frame);

            bc.ProcessImage(frame);
            Rectangle[] rects = bc.GetObjectsRectangles();

            if (rects.Length > 0)
            {
                AForge.Point closest = new AForge.Point(100000, 100000);

                foreach (var r in rects)
                {
                    var p = new AForge.Point(r.Left + r.Width / 2, r.Top + r.Height / 2);

                    var d2 = center.SquaredDistanceTo(closest);
                    var d1 = center.SquaredDistanceTo(p);

                    if (d1 < d2)
                    {
                        closest = p;
                    }
                }

                var closestDistance = center.SquaredDistanceTo(closest);
                var shouldFire      = closestDistance < 20;
                var delta           = closest - center;
                _controller.Update(delta.X, delta.Y, shouldFire);

                var g = Graphics.FromImage(frame);
                using (Pen p = new Pen(Color.Red))
                {
                    foreach (Rectangle r in rects)
                    {
                        g.DrawRectangle(p, r);
                        g.DrawString("+", new Font("Consolas", 10), Brushes.Red, r.X, r.Y);
                    }
                }
                using (Pen p = new Pen(Color.Green))
                {
                    g.DrawRectangle(p, closest.X - 2, closest.Y - 2, 5, 5);
                }
            }

            return(frame);
        }