static IEnumerable <Point> LeftLeftLine(RoutingAssistent assist, Point start, Point end, double distance) { var minX = Math.Min(start.X, end.X) - distance * NormalDistance; var minX2 = assist.FindVerticalRoutingSlotLeft(Math.Min(start.X, end.X) - MinimalDistance, start.Y, end.Y); minX = Math.Min(minX, minX2); List <Point> linePoints = new List <Point>() { start, new Point { X = minX, Y = start.Y }, new Point { X = minX, Y = end.Y }, end }; return(linePoints); }