EtchBendLines/EtchBendLines/Bend.cs

using netDxf;
using netDxf.Entities;
using netDxf.Tables;
using System;
using System.Collections.Generic;

namespace EtchBendLines
{
    public class Bend
	{
        public Line Line { get; set; }

        public MText BendNote { get; set; }

        public double YIntercept
		{
			get { return Line.YIntercept(); }
		}

		public double Slope
		{
			get { return Line.Slope(); }
		}

		public bool IsVertical
		{
			get { return Line.IsVertical(); }
		}

		public bool IsHorizontal
		{
			get { return Line.IsHorizontal(); }
		}

        public bool IsParallelTo(Bend bend)
        {
            return Line.IsParallelTo(bend.Line);
        }

        public bool IsPerpendicularTo(Bend bend)
        {
            return Line.IsPerpendicularTo(bend.Line);
        }

        public bool IsCollinearTo(Bend bend)
		{
			if (bend.IsVertical || this.IsVertical)
				return (bend.IsVertical && this.IsVertical && bend.YIntercept == this.YIntercept);

			if (bend.YIntercept != this.YIntercept)
				return false;

			return bend.Slope == this.Slope;
		}

		public List<Line> GetEtchLines(double etchLength)
		{
			var lines = new List<Line>();

			var etchLayer = new Layer("ETCH")
			{
				Color = AciColor.Green,
			};

			var startPoint = new Vector2(Line.StartPoint.X, Line.StartPoint.Y);
			var endPoint = new Vector2(Line.EndPoint.X, Line.EndPoint.Y);
			var bendLength = startPoint.DistanceTo(endPoint);

			if (bendLength < (etchLength * 3.0))
			{
				var fullLengthLine = new Line(Line.StartPoint, Line.EndPoint)
				{
					Layer = etchLayer
				};

				lines.Add(fullLengthLine);

				return lines;
			}
			else
			{
				var angle = startPoint.AngleTo(endPoint);

				if (Line.IsVertical())
				{
					var x = Line.StartPoint.X;

					var bottomY1 = Line.StartPoint.Y < Line.EndPoint.Y ? Line.StartPoint.Y : Line.EndPoint.Y;
					var bottomY2 = bottomY1 + etchLength;

					var topY1 = Line.StartPoint.Y > Line.EndPoint.Y ? Line.StartPoint.Y : Line.EndPoint.Y;
					var topY2 = topY1 - etchLength;

					var p1 = new Vector2(x, bottomY1);
					var p2 = new Vector2(x, bottomY2);

					var p3 = new Vector2(x, topY1);
					var p4 = new Vector2(x, topY2);

					var bottomPoint = Line.StartPoint.Y < Line.EndPoint.Y ? Line.StartPoint : Line.EndPoint;
					var bottomOffsetPoint = new Vector2(bottomPoint.X, bottomPoint.Y + etchLength);

					var line1 = new Line(p1, p2)
					{
						Layer = etchLayer
					};

					var line2 = new Line(p3, p4)
					{
						Layer = etchLayer
					};

					lines.Add(line1);
					lines.Add(line2);
				}
				else
				{
					var start = Line.StartPoint.ToVector2();
					var end = Line.EndPoint.ToVector2();

					var x1 = Math.Cos(angle);
					var y1 = Math.Sin(angle);

					var p1 = new Vector2(start.X, start.Y);
					var p2 = new Vector2(start.X + x1, start.Y + y1);

					var p3 = new Vector2(end.X, end.Y);
					var p4 = new Vector2(end.X - x1, end.Y - y1);

					var line1 = new Line(p1, p2)
					{
						Layer = etchLayer
					};

					var line2 = new Line(p3, p4)
					{
						Layer = etchLayer
					};

					lines.Add(line1);
					lines.Add(line2);
				}
			}

			return lines;
		}

		public BendDirection Direction { get; set; }

		public double Length
		{
			get
			{
				var x = Line.EndPoint.X - Line.StartPoint.X;
				var y = Line.EndPoint.Y - Line.StartPoint.Y;
				return Math.Sqrt(x * x + y * y);
			}
		}

        public double? Radius { get; set; }

        public double? Angle { get; set; }

        public override string ToString()
        {
            return $"{Direction.ToString()} {Angle}° R{Radius}";
        }
    }
}