feat: add lead-out parameters and tab toggle to CuttingParametersForm

Restructure the cutting parameters dialog with separate Lead-In and
Lead-Out GroupBoxes per tab, exposing editable length/angle/radius
fields for lead-outs (previously hardcoded). Add Tabs section with
enable checkbox and width control. Also fix lead-in/lead-out angle
calculations and convert cutting strategy output to incremental mode.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

OpenNest.Core/CNC/ArcMove.cs

@@ -65,7 +65,8 @@ namespace OpenNest.CNC
         {
             return new ArcMove(EndPoint, CenterPoint, Rotation)
             {
-                Layer = Layer
+                Layer = Layer,
+                Suppressed = Suppressed
             };
         }
 

OpenNest.Core/CNC/CuttingStrategy/ContourCuttingStrategy.cs

@@ -63,6 +63,10 @@ namespace OpenNest.CNC.CuttingStrategy
                 result.Codes.AddRange(leadOut.Generate(perimeterPt, normal, winding));
             }
 
+            // Convert to incremental mode to match the convention used by
+            // the rest of the system (rendering, bounding box, drag, etc.).
+            result.Mode = Mode.Incremental;
+
             return new CuttingResult
             {
                 Program = result,
@@ -102,7 +106,7 @@ namespace OpenNest.CNC.CuttingStrategy
             return ordered;
         }
 
-        private ContourType DetectContourType(Shape cutout)
+        public static ContourType DetectContourType(Shape cutout)
         {
             if (cutout.Entities.Count == 1 && cutout.Entities[0] is Circle)
                 return ContourType.ArcCircle;
@@ -110,7 +114,7 @@ namespace OpenNest.CNC.CuttingStrategy
             return ContourType.Internal;
         }
 
-        private double ComputeNormal(Vector point, Entity entity, ContourType contourType)
+        public static double ComputeNormal(Vector point, Entity entity, ContourType contourType)
         {
             double normal;
 
@@ -141,7 +145,7 @@ namespace OpenNest.CNC.CuttingStrategy
             return Math.Angle.NormalizeRad(normal);
         }
 
-        private RotationType DetermineWinding(Shape shape)
+        public static RotationType DetermineWinding(Shape shape)
         {
             // Use signed area: positive = CCW, negative = CW
             var area = shape.Area();

OpenNest.Core/CNC/CuttingStrategy/LeadIns/ArcLeadIn.cs

@@ -19,7 +19,7 @@ namespace OpenNest.CNC.CuttingStrategy
             return new List<ICode>
             {
                 new RapidMove(piercePoint),
-                new ArcMove(contourStartPoint, arcCenter, winding)
+                new ArcMove(contourStartPoint, arcCenter, winding) { Layer = LayerType.Leadin }
             };
         }
 

OpenNest.Core/CNC/CuttingStrategy/LeadIns/CleanHoleLeadIn.cs

@@ -27,8 +27,8 @@ namespace OpenNest.CNC.CuttingStrategy
             return new List<ICode>
             {
                 new RapidMove(piercePoint),
-                new LinearMove(arcStart),
-                new ArcMove(contourStartPoint, arcCenter, winding)
+                new LinearMove(arcStart) { Layer = LayerType.Leadin },
+                new ArcMove(contourStartPoint, arcCenter, winding) { Layer = LayerType.Leadin }
             };
         }
 

OpenNest.Core/CNC/CuttingStrategy/LeadIns/LineArcLeadIn.cs

@@ -27,8 +27,8 @@ namespace OpenNest.CNC.CuttingStrategy
             return new List<ICode>
             {
                 new RapidMove(piercePoint),
-                new LinearMove(arcStart),
-                new ArcMove(contourStartPoint, arcCenter, winding)
+                new LinearMove(arcStart) { Layer = LayerType.Leadin },
+                new ArcMove(contourStartPoint, arcCenter, winding) { Layer = LayerType.Leadin }
             };
         }
 

OpenNest.Core/CNC/CuttingStrategy/LeadIns/LineLeadIn.cs

@@ -17,13 +17,13 @@ namespace OpenNest.CNC.CuttingStrategy
             return new List<ICode>
             {
                 new RapidMove(piercePoint),
-                new LinearMove(contourStartPoint)
+                new LinearMove(contourStartPoint) { Layer = LayerType.Leadin }
             };
         }
 
         public override Vector GetPiercePoint(Vector contourStartPoint, double contourNormalAngle)
         {
-            var approachAngle = contourNormalAngle + Angle.ToRadians(ApproachAngle);
+            var approachAngle = contourNormalAngle + Angle.HalfPI - Angle.ToRadians(ApproachAngle);
             return new Vector(
                 contourStartPoint.X + Length * System.Math.Cos(approachAngle),
                 contourStartPoint.Y + Length * System.Math.Sin(approachAngle));

OpenNest.Core/CNC/CuttingStrategy/LeadIns/LineLineLeadIn.cs

@@ -16,7 +16,7 @@ namespace OpenNest.CNC.CuttingStrategy
         {
             var piercePoint = GetPiercePoint(contourStartPoint, contourNormalAngle);
 
-            var secondAngle = contourNormalAngle + Angle.ToRadians(ApproachAngle1);
+            var secondAngle = contourNormalAngle + Angle.HalfPI - Angle.ToRadians(ApproachAngle1);
             var midPoint = new Vector(
                 contourStartPoint.X + Length2 * System.Math.Cos(secondAngle),
                 contourStartPoint.Y + Length2 * System.Math.Sin(secondAngle));
@@ -24,14 +24,14 @@ namespace OpenNest.CNC.CuttingStrategy
             return new List<ICode>
             {
                 new RapidMove(piercePoint),
-                new LinearMove(midPoint),
-                new LinearMove(contourStartPoint)
+                new LinearMove(midPoint) { Layer = LayerType.Leadin },
+                new LinearMove(contourStartPoint) { Layer = LayerType.Leadin }
             };
         }
 
         public override Vector GetPiercePoint(Vector contourStartPoint, double contourNormalAngle)
         {
-            var secondAngle = contourNormalAngle + Angle.ToRadians(ApproachAngle1);
+            var secondAngle = contourNormalAngle + Angle.HalfPI - Angle.ToRadians(ApproachAngle1);
             var midX = contourStartPoint.X + Length2 * System.Math.Cos(secondAngle);
             var midY = contourStartPoint.Y + Length2 * System.Math.Sin(secondAngle);
 

OpenNest.Core/CNC/CuttingStrategy/LeadOuts/ArcLeadOut.cs

@@ -20,7 +20,7 @@ namespace OpenNest.CNC.CuttingStrategy
 
             return new List<ICode>
             {
-                new ArcMove(endPoint, arcCenter, winding)
+                new ArcMove(endPoint, arcCenter, winding) { Layer = LayerType.Leadout }
             };
         }
     }

OpenNest.Core/CNC/CuttingStrategy/LeadOuts/LineLeadOut.cs

@@ -12,14 +12,14 @@ namespace OpenNest.CNC.CuttingStrategy
         public override List<ICode> Generate(Vector contourEndPoint, double contourNormalAngle,
             RotationType winding = RotationType.CW)
         {
-            var overcutAngle = contourNormalAngle + Angle.ToRadians(ApproachAngle);
+            var overcutAngle = contourNormalAngle + Angle.HalfPI - Angle.ToRadians(ApproachAngle);
             var endPoint = new Vector(
                 contourEndPoint.X + Length * System.Math.Cos(overcutAngle),
                 contourEndPoint.Y + Length * System.Math.Sin(overcutAngle));
 
             return new List<ICode>
             {
-                new LinearMove(endPoint)
+                new LinearMove(endPoint) { Layer = LayerType.Leadout }
             };
         }
     }

OpenNest.Core/CNC/LinearMove.cs

@@ -31,7 +31,8 @@ namespace OpenNest.CNC
         {
             return new LinearMove(EndPoint)
             {
-                Layer = Layer
+                Layer = Layer,
+                Suppressed = Suppressed
             };
         }
 

OpenNest.Core/CNC/Motion.cs

@@ -12,6 +12,8 @@ namespace OpenNest.CNC
 
         public int Feedrate { get; set; }
 
+        public bool Suppressed { get; set; }
+
         protected Motion()
         {
             Feedrate = CNC.Feedrate.UseDefault;

OpenNest.Core/CNC/RapidMove.cs

@@ -26,7 +26,10 @@ namespace OpenNest.CNC
 
         public override ICode Clone()
         {
-            return new RapidMove(EndPoint);
+            return new RapidMove(EndPoint)
+            {
+                Suppressed = Suppressed
+            };
         }
 
         public override string ToString()

OpenNest.Core/Part.cs

@@ -22,6 +22,7 @@ namespace OpenNest
     {
         private Vector location;
         private bool ownsProgram;
+        private double preLeadInRotation;
 
         public readonly Drawing BaseDrawing;
 
@@ -56,6 +57,38 @@ namespace OpenNest
 
         public bool HasManualLeadIns { get; set; }
 
+        public bool LeadInsLocked { get; set; }
+
+        public CNC.CuttingStrategy.CuttingParameters CuttingParameters { get; set; }
+
+        public void ApplyLeadIns(CNC.CuttingStrategy.CuttingParameters parameters, Vector approachPoint)
+        {
+            preLeadInRotation = Rotation;
+            var strategy = new CNC.CuttingStrategy.ContourCuttingStrategy { Parameters = parameters };
+            var result = strategy.Apply(Program, approachPoint);
+            Program = result.Program;
+            CuttingParameters = parameters;
+            HasManualLeadIns = true;
+            UpdateBounds();
+        }
+
+        public void RemoveLeadIns()
+        {
+            var rotation = preLeadInRotation;
+            var location = Location;
+            Program = BaseDrawing.Program.Clone() as Program;
+            ownsProgram = true;
+
+            if (!Math.Tolerance.IsEqualTo(rotation, 0))
+                Program.Rotate(rotation);
+
+            Location = location;
+            HasManualLeadIns = false;
+            LeadInsLocked = false;
+            CuttingParameters = null;
+            UpdateBounds();
+        }
+
         /// <summary>
         /// Gets the rotation of the part in radians.
         /// </summary>

OpenNest.Core/Plate.cs

@@ -88,6 +88,8 @@ namespace OpenNest
         /// </summary>
         public Material Material { get; set; }
 
+        public CNC.CuttingStrategy.CuttingParameters CuttingParameters { get; set; }
+
         /// <summary>
         /// Material grain direction in radians. 0 = horizontal.
         /// </summary>

OpenNest.Core/SpecialLayers.cs

@@ -13,9 +13,9 @@ namespace OpenNest
 
         public static readonly Layer Display = new Layer("DISPLAY") { Color = Color.Cyan };
 
-        public static readonly Layer Leadin = new Layer("LEADIN") { Color = Color.Yellow };
+        public static readonly Layer Leadin = new Layer("LEADIN") { Color = Color.Brown };
 
-        public static readonly Layer Leadout = new Layer("LEADOUT") { Color = Color.Yellow };
+        public static readonly Layer Leadout = new Layer("LEADOUT") { Color = Color.Brown };
 
         public static readonly Layer Scribe = new Layer("SCRIBE") { Color = Color.Magenta };
     }

OpenNest.Engine/LeadInAssigner.cs

@@ -0,0 +1,40 @@
+using OpenNest.Engine.Sequencing;
+using OpenNest.Geometry;
+using System.Linq;
+
+namespace OpenNest.Engine
+{
+    public class LeadInAssigner
+    {
+        public IPartSequencer Sequencer { get; set; }
+
+        public void Assign(Plate plate)
+        {
+            var parameters = plate.CuttingParameters;
+            if (parameters == null)
+                return;
+
+            var sequenced = Sequencer.Sequence(plate.Parts.ToList(), plate);
+            var currentPoint = PlateHelper.GetExitPoint(plate);
+
+            foreach (var sp in sequenced)
+            {
+                var part = sp.Part;
+
+                if (part.LeadInsLocked)
+                {
+                    currentPoint = part.Location;
+                    continue;
+                }
+
+                if (part.HasManualLeadIns)
+                    part.RemoveLeadIns();
+
+                var localApproach = currentPoint - part.Location;
+                part.ApplyLeadIns(parameters, localApproach);
+
+                currentPoint = part.Location;
+            }
+        }
+    }
+}

OpenNest.IO/NestFormat.cs

@@ -74,6 +74,8 @@ namespace OpenNest.IO
             public double X { get; init; }
             public double Y { get; init; }
             public double Rotation { get; init; }
+            public bool HasManualLeadIns { get; init; }
+            public bool LeadInsLocked { get; init; }
         }
 
         public record CutOffDto

OpenNest.IO/NestReader.cs

@@ -214,6 +214,8 @@ namespace OpenNest.IO
                     var part = new Part(dwg);
                     part.Rotate(partDto.Rotation);
                     part.Offset(new Vector(partDto.X, partDto.Y));
+                    part.HasManualLeadIns = partDto.HasManualLeadIns;
+                    part.LeadInsLocked = partDto.LeadInsLocked;
                     plate.Parts.Add(part);
                 }
 

OpenNest.IO/NestWriter.cs

@@ -173,7 +173,9 @@ namespace OpenNest.IO
                         DrawingId = match.Key,
                         X = part.Location.X,
                         Y = part.Location.Y,
-                        Rotation = part.Rotation
+                        Rotation = part.Rotation,
+                        HasManualLeadIns = part.HasManualLeadIns,
+                        LeadInsLocked = part.LeadInsLocked
                     });
                 }
 
@@ -336,6 +338,9 @@ namespace OpenNest.IO
                         if (arcMove.Layer != LayerType.Cut)
                             sb.Append(GetLayerString(arcMove.Layer));
 
+                        if (arcMove.Suppressed)
+                            sb.Append(":SUPPRESSED");
+
                         return sb.ToString();
                     }
 
@@ -357,6 +362,9 @@ namespace OpenNest.IO
                         if (linearMove.Layer != LayerType.Cut)
                             sb.Append(GetLayerString(linearMove.Layer));
 
+                        if (linearMove.Suppressed)
+                            sb.Append(":SUPPRESSED");
+
                         return sb.ToString();
                     }
 

OpenNest.IO/ProgramReader.cs

@@ -142,6 +142,7 @@ namespace OpenNest.IO
             double x = 0;
             double y = 0;
             var layer = LayerType.Cut;
+            var suppressed = false;
 
             while (section == CodeSection.Line)
             {
@@ -164,25 +165,32 @@ namespace OpenNest.IO
 
                     case ':':
                         {
-                            var value = code.Value.Trim().ToUpper();
+                            var tags = code.Value.Trim().ToUpper().Split(':');
 
-                            switch (value)
+                            foreach (var tag in tags)
                             {
-                                case "DISPLAY":
-                                    layer = LayerType.Display;
-                                    break;
+                                switch (tag)
+                                {
+                                    case "DISPLAY":
+                                        layer = LayerType.Display;
+                                        break;
 
-                                case "LEADIN":
-                                    layer = LayerType.Leadin;
-                                    break;
+                                    case "LEADIN":
+                                        layer = LayerType.Leadin;
+                                        break;
 
-                                case "LEADOUT":
-                                    layer = LayerType.Leadout;
-                                    break;
+                                    case "LEADOUT":
+                                        layer = LayerType.Leadout;
+                                        break;
 
-                                case "SCRIBE":
-                                    layer = LayerType.Scribe;
-                                    break;
+                                    case "SCRIBE":
+                                        layer = LayerType.Scribe;
+                                        break;
+
+                                    case "SUPPRESSED":
+                                        suppressed = true;
+                                        break;
+                                }
                             }
                             break;
                         }
@@ -195,7 +203,7 @@ namespace OpenNest.IO
             if (isRapid)
                 program.Codes.Add(new RapidMove(x, y));
             else
-                program.Codes.Add(new LinearMove(x, y) { Layer = layer });
+                program.Codes.Add(new LinearMove(x, y) { Layer = layer, Suppressed = suppressed });
         }
 
         private void ReadArc(RotationType rotation)
@@ -205,6 +213,7 @@ namespace OpenNest.IO
             double i = 0;
             double j = 0;
             var layer = LayerType.Cut;
+            var suppressed = false;
 
             while (section == CodeSection.Arc)
             {
@@ -236,25 +245,32 @@ namespace OpenNest.IO
 
                     case ':':
                         {
-                            var value = code.Value.Trim().ToUpper();
+                            var tags = code.Value.Trim().ToUpper().Split(':');
 
-                            switch (value)
+                            foreach (var tag in tags)
                             {
-                                case "DISPLAY":
-                                    layer = LayerType.Display;
-                                    break;
+                                switch (tag)
+                                {
+                                    case "DISPLAY":
+                                        layer = LayerType.Display;
+                                        break;
 
-                                case "LEADIN":
-                                    layer = LayerType.Leadin;
-                                    break;
+                                    case "LEADIN":
+                                        layer = LayerType.Leadin;
+                                        break;
 
-                                case "LEADOUT":
-                                    layer = LayerType.Leadout;
-                                    break;
+                                    case "LEADOUT":
+                                        layer = LayerType.Leadout;
+                                        break;
 
-                                case "SCRIBE":
-                                    layer = LayerType.Scribe;
-                                    break;
+                                    case "SCRIBE":
+                                        layer = LayerType.Scribe;
+                                        break;
+
+                                    case "SUPPRESSED":
+                                        suppressed = true;
+                                        break;
+                                }
                             }
                             break;
                         }
@@ -269,7 +285,8 @@ namespace OpenNest.IO
                 EndPoint = new Vector(x, y),
                 CenterPoint = new Vector(i, j),
                 Rotation = rotation,
-                Layer = layer
+                Layer = layer,
+                Suppressed = suppressed
             });
         }
 

OpenNest.Tests/LeadInAssignerTests.cs

@@ -0,0 +1,98 @@
+using OpenNest.CNC;
+using OpenNest.CNC.CuttingStrategy;
+using OpenNest.Engine;
+using OpenNest.Engine.Sequencing;
+using OpenNest.Geometry;
+
+namespace OpenNest.Tests;
+
+public class LeadInAssignerTests
+{
+    private static Part MakeSquarePartAt(double x, double y)
+    {
+        var pgm = new Program();
+        pgm.Codes.Add(new RapidMove(new Vector(0, 0)));
+        pgm.Codes.Add(new LinearMove(new Vector(0, 10)));
+        pgm.Codes.Add(new LinearMove(new Vector(10, 10)));
+        pgm.Codes.Add(new LinearMove(new Vector(10, 0)));
+        pgm.Codes.Add(new LinearMove(new Vector(0, 0)));
+        var drawing = new Drawing("test", pgm);
+        return new Part(drawing, new Vector(x, y));
+    }
+
+    [Fact]
+    public void Assign_SetsHasManualLeadInsOnAllParts()
+    {
+        var plate = new Plate(60, 120);
+        plate.Parts.Add(MakeSquarePartAt(10, 10));
+        plate.Parts.Add(MakeSquarePartAt(30, 30));
+        plate.CuttingParameters = new CuttingParameters
+        {
+            ExternalLeadIn = new LineLeadIn { Length = 0.5, ApproachAngle = 90 }
+        };
+
+        var assigner = new LeadInAssigner { Sequencer = new LeftSideSequencer() };
+        assigner.Assign(plate);
+
+        Assert.All(plate.Parts, p => Assert.True(p.HasManualLeadIns));
+    }
+
+    [Fact]
+    public void Assign_SkipsLockedParts()
+    {
+        var plate = new Plate(60, 120);
+        var lockedPart = MakeSquarePartAt(10, 10);
+        lockedPart.LeadInsLocked = true;
+        lockedPart.HasManualLeadIns = true;
+        var originalProgram = lockedPart.Program;
+
+        plate.Parts.Add(lockedPart);
+        plate.Parts.Add(MakeSquarePartAt(30, 30));
+        plate.CuttingParameters = new CuttingParameters
+        {
+            ExternalLeadIn = new LineLeadIn { Length = 0.5, ApproachAngle = 90 }
+        };
+
+        var assigner = new LeadInAssigner { Sequencer = new LeftSideSequencer() };
+        assigner.Assign(plate);
+
+        Assert.Same(originalProgram, lockedPart.Program);
+    }
+
+    [Fact]
+    public void Assign_RemovesExistingLeadInsBeforeReapply()
+    {
+        var plate = new Plate(60, 120);
+        plate.Parts.Add(MakeSquarePartAt(10, 10));
+        plate.CuttingParameters = new CuttingParameters
+        {
+            ExternalLeadIn = new LineLeadIn { Length = 0.5, ApproachAngle = 90 }
+        };
+
+        var assigner = new LeadInAssigner { Sequencer = new LeftSideSequencer() };
+        assigner.Assign(plate);
+        var countAfterFirst = plate.Parts[0].Program.Codes.Count;
+
+        assigner.Assign(plate);
+        var countAfterSecond = plate.Parts[0].Program.Codes.Count;
+
+        Assert.Equal(countAfterFirst, countAfterSecond);
+    }
+
+    [Fact]
+    public void Assign_PartsContainLeadinLayerCodes()
+    {
+        var plate = new Plate(60, 120);
+        plate.Parts.Add(MakeSquarePartAt(10, 10));
+        plate.CuttingParameters = new CuttingParameters
+        {
+            ExternalLeadIn = new LineLeadIn { Length = 0.5, ApproachAngle = 90 }
+        };
+
+        var assigner = new LeadInAssigner { Sequencer = new LeftSideSequencer() };
+        assigner.Assign(plate);
+
+        var hasLeadin = plate.Parts[0].Program.Codes.OfType<LinearMove>().Any(m => m.Layer == LayerType.Leadin);
+        Assert.True(hasLeadin);
+    }
+}

OpenNest.Tests/LeadInLayerTagTests.cs

@@ -0,0 +1,90 @@
+using OpenNest.CNC;
+using OpenNest.CNC.CuttingStrategy;
+using OpenNest.Geometry;
+
+namespace OpenNest.Tests;
+
+public class LeadInLayerTagTests
+{
+    private static readonly Vector Point = new(5, 5);
+    private const double Normal = 0.0;
+
+    [Fact]
+    public void LineLeadIn_SetsLeadinLayer()
+    {
+        var leadIn = new LineLeadIn { Length = 0.5, ApproachAngle = 90 };
+        var codes = leadIn.Generate(Point, Normal);
+        var linear = codes.OfType<LinearMove>().Single();
+        Assert.Equal(LayerType.Leadin, linear.Layer);
+    }
+
+    [Fact]
+    public void ArcLeadIn_SetsLeadinLayer()
+    {
+        var leadIn = new ArcLeadIn { Radius = 0.25 };
+        var codes = leadIn.Generate(Point, Normal);
+        var arc = codes.OfType<ArcMove>().Single();
+        Assert.Equal(LayerType.Leadin, arc.Layer);
+    }
+
+    [Fact]
+    public void LineArcLeadIn_SetsLeadinLayerOnAllMoves()
+    {
+        var leadIn = new LineArcLeadIn { LineLength = 0.5, ArcRadius = 0.25, ApproachAngle = 135 };
+        var codes = leadIn.Generate(Point, Normal);
+        Assert.All(codes.OfType<LinearMove>(), m => Assert.Equal(LayerType.Leadin, m.Layer));
+        Assert.All(codes.OfType<ArcMove>(), m => Assert.Equal(LayerType.Leadin, m.Layer));
+    }
+
+    [Fact]
+    public void CleanHoleLeadIn_SetsLeadinLayerOnAllMoves()
+    {
+        var leadIn = new CleanHoleLeadIn { LineLength = 0.5, ArcRadius = 0.25, Kerf = 0.05 };
+        var codes = leadIn.Generate(Point, Normal);
+        Assert.All(codes.OfType<LinearMove>(), m => Assert.Equal(LayerType.Leadin, m.Layer));
+        Assert.All(codes.OfType<ArcMove>(), m => Assert.Equal(LayerType.Leadin, m.Layer));
+    }
+
+    [Fact]
+    public void LineLineLeadIn_SetsLeadinLayerOnAllMoves()
+    {
+        var leadIn = new LineLineLeadIn { Length1 = 0.5, Length2 = 0.3, ApproachAngle1 = 90, ApproachAngle2 = 90 };
+        var codes = leadIn.Generate(Point, Normal);
+        Assert.All(codes.OfType<LinearMove>(), m => Assert.Equal(LayerType.Leadin, m.Layer));
+    }
+
+    [Fact]
+    public void NoLeadIn_NoLinearOrArcMoves()
+    {
+        var leadIn = new NoLeadIn();
+        var codes = leadIn.Generate(Point, Normal);
+        Assert.Empty(codes.OfType<LinearMove>());
+        Assert.Empty(codes.OfType<ArcMove>());
+    }
+
+    [Fact]
+    public void LineLeadOut_SetsLeadoutLayer()
+    {
+        var leadOut = new LineLeadOut { Length = 0.5, ApproachAngle = 90 };
+        var codes = leadOut.Generate(Point, Normal);
+        var linear = codes.OfType<LinearMove>().Single();
+        Assert.Equal(LayerType.Leadout, linear.Layer);
+    }
+
+    [Fact]
+    public void ArcLeadOut_SetsLeadoutLayer()
+    {
+        var leadOut = new ArcLeadOut { Radius = 0.25 };
+        var codes = leadOut.Generate(Point, Normal);
+        var arc = codes.OfType<ArcMove>().Single();
+        Assert.Equal(LayerType.Leadout, arc.Layer);
+    }
+
+    [Fact]
+    public void NoLeadOut_ReturnsEmptyList()
+    {
+        var leadOut = new NoLeadOut();
+        var codes = leadOut.Generate(Point, Normal);
+        Assert.Empty(codes);
+    }
+}

OpenNest.Tests/MotionSuppressedTests.cs

@@ -0,0 +1,45 @@
+using OpenNest.CNC;
+using OpenNest.Geometry;
+
+namespace OpenNest.Tests;
+
+public class MotionSuppressedTests
+{
+    [Fact]
+    public void LinearMove_Suppressed_DefaultsFalse()
+    {
+        var move = new LinearMove(new Vector(1, 2));
+        Assert.False(move.Suppressed);
+    }
+
+    [Fact]
+    public void ArcMove_Suppressed_DefaultsFalse()
+    {
+        var move = new ArcMove(new Vector(1, 2), new Vector(0, 0));
+        Assert.False(move.Suppressed);
+    }
+
+    [Fact]
+    public void RapidMove_Suppressed_DefaultsFalse()
+    {
+        var move = new RapidMove(new Vector(1, 2));
+        Assert.False(move.Suppressed);
+    }
+
+    [Fact]
+    public void Suppressed_CanBeSet()
+    {
+        var move = new LinearMove(new Vector(1, 2));
+        move.Suppressed = true;
+        Assert.True(move.Suppressed);
+    }
+
+    [Fact]
+    public void Clone_PreservesSuppressed()
+    {
+        var move = new LinearMove(new Vector(1, 2));
+        move.Suppressed = true;
+        var clone = (LinearMove)move.Clone();
+        Assert.True(clone.Suppressed);
+    }
+}

OpenNest.Tests/PartLeadInTests.cs

@@ -0,0 +1,127 @@
+using OpenNest.CNC;
+using OpenNest.CNC.CuttingStrategy;
+using OpenNest.Geometry;
+
+namespace OpenNest.Tests;
+
+public class PartLeadInTests
+{
+    private static Part MakeSquarePart()
+    {
+        var pgm = new Program();
+        pgm.Codes.Add(new RapidMove(new Vector(0, 0)));
+        pgm.Codes.Add(new LinearMove(new Vector(0, 10)));
+        pgm.Codes.Add(new LinearMove(new Vector(10, 10)));
+        pgm.Codes.Add(new LinearMove(new Vector(10, 0)));
+        pgm.Codes.Add(new LinearMove(new Vector(0, 0)));
+        var drawing = new Drawing("test", pgm);
+        return new Part(drawing);
+    }
+
+    [Fact]
+    public void ApplyLeadIns_SetsHasManualLeadIns()
+    {
+        var part = MakeSquarePart();
+        var parameters = new CuttingParameters
+        {
+            ExternalLeadIn = new LineLeadIn { Length = 0.5, ApproachAngle = 90 },
+            InternalLeadIn = new LineLeadIn { Length = 0.25, ApproachAngle = 90 }
+        };
+
+        part.ApplyLeadIns(parameters, new Vector(-5, -5));
+
+        Assert.True(part.HasManualLeadIns);
+    }
+
+    [Fact]
+    public void ApplyLeadIns_StoresCuttingParameters()
+    {
+        var part = MakeSquarePart();
+        var parameters = new CuttingParameters
+        {
+            ExternalLeadIn = new LineLeadIn { Length = 0.5, ApproachAngle = 90 },
+            InternalLeadIn = new LineLeadIn { Length = 0.25, ApproachAngle = 90 }
+        };
+
+        part.ApplyLeadIns(parameters, new Vector(-5, -5));
+
+        Assert.Same(parameters, part.CuttingParameters);
+    }
+
+    [Fact]
+    public void ApplyLeadIns_ProgramContainsLeadinCodes()
+    {
+        var part = MakeSquarePart();
+        var parameters = new CuttingParameters
+        {
+            ExternalLeadIn = new LineLeadIn { Length = 0.5, ApproachAngle = 90 }
+        };
+
+        part.ApplyLeadIns(parameters, new Vector(-5, -5));
+
+        var hasLeadin = part.Program.Codes.OfType<LinearMove>().Any(m => m.Layer == LayerType.Leadin);
+        Assert.True(hasLeadin);
+    }
+
+    [Fact]
+    public void RemoveLeadIns_RestoresOriginalProgram()
+    {
+        var part = MakeSquarePart();
+        var originalCodeCount = part.Program.Codes.Count;
+        var parameters = new CuttingParameters
+        {
+            ExternalLeadIn = new LineLeadIn { Length = 0.5, ApproachAngle = 90 }
+        };
+
+        part.ApplyLeadIns(parameters, new Vector(-5, -5));
+        part.RemoveLeadIns();
+
+        Assert.False(part.HasManualLeadIns);
+        Assert.Null(part.CuttingParameters);
+        Assert.Equal(originalCodeCount, part.Program.Codes.Count);
+    }
+
+    [Fact]
+    public void RemoveLeadIns_PreservesRotation()
+    {
+        var part = MakeSquarePart();
+        part.Rotate(System.Math.PI / 4); // 45 degrees
+        var rotation = part.Rotation;
+
+        var parameters = new CuttingParameters
+        {
+            ExternalLeadIn = new LineLeadIn { Length = 0.5, ApproachAngle = 90 }
+        };
+
+        part.ApplyLeadIns(parameters, new Vector(-5, -5));
+        part.RemoveLeadIns();
+
+        Assert.Equal(rotation, part.Rotation, 6);
+    }
+
+    [Fact]
+    public void RemoveLeadIns_PreservesLocation()
+    {
+        var part = MakeSquarePart();
+        part.Offset(20, 30);
+        var location = part.Location;
+
+        var parameters = new CuttingParameters
+        {
+            ExternalLeadIn = new LineLeadIn { Length = 0.5, ApproachAngle = 90 }
+        };
+
+        part.ApplyLeadIns(parameters, new Vector(-5, -5));
+        part.RemoveLeadIns();
+
+        Assert.Equal(location.X, part.Location.X, 6);
+        Assert.Equal(location.Y, part.Location.Y, 6);
+    }
+
+    [Fact]
+    public void LeadInsLocked_DefaultsFalse()
+    {
+        var part = MakeSquarePart();
+        Assert.False(part.LeadInsLocked);
+    }
+}

OpenNest/Actions/ActionLeadIn.cs

@@ -0,0 +1,330 @@
+using OpenNest.CNC.CuttingStrategy;
+using OpenNest.Controls;
+using OpenNest.Converters;
+using OpenNest.Geometry;
+using System.Collections.Generic;
+using System.ComponentModel;
+using System.Drawing;
+using System.Drawing.Drawing2D;
+using System.Windows.Forms;
+
+namespace OpenNest.Actions
+{
+    [DisplayName("Place Lead-in")]
+    public class ActionLeadIn : Action
+    {
+        private LayoutPart selectedLayoutPart;
+        private Part selectedPart;
+        private ShapeProfile profile;
+        private List<ShapeInfo> contours;
+        private Vector snapPoint;
+        private Entity snapEntity;
+        private ContourType snapContourType;
+        private double snapNormal;
+        private bool hasSnap;
+        private ContextMenuStrip contextMenu;
+
+        public ActionLeadIn(PlateView plateView)
+            : base(plateView)
+        {
+            ConnectEvents();
+        }
+
+        public override void ConnectEvents()
+        {
+            plateView.MouseMove += OnMouseMove;
+            plateView.MouseDown += OnMouseDown;
+            plateView.KeyDown += OnKeyDown;
+            plateView.Paint += OnPaint;
+        }
+
+        public override void DisconnectEvents()
+        {
+            plateView.MouseMove -= OnMouseMove;
+            plateView.MouseDown -= OnMouseDown;
+            plateView.KeyDown -= OnKeyDown;
+            plateView.Paint -= OnPaint;
+
+            contextMenu?.Dispose();
+            contextMenu = null;
+
+            selectedLayoutPart = null;
+            selectedPart = null;
+            profile = null;
+            contours = null;
+            hasSnap = false;
+            plateView.Invalidate();
+        }
+
+        public override void CancelAction() { }
+
+        public override bool IsBusy() => selectedPart != null;
+
+        private void OnMouseMove(object sender, MouseEventArgs e)
+        {
+            if (selectedPart == null || contours == null)
+                return;
+
+            var worldPt = plateView.CurrentPoint;
+
+            // Transform world point into program-local space by subtracting the
+            // part's location. The contour shapes are already in the program's
+            // rotated coordinate system, so no additional un-rotation is needed.
+            var localPt = new Vector(worldPt.X - selectedPart.Location.X,
+                                     worldPt.Y - selectedPart.Location.Y);
+
+            // Find closest contour and point
+            var bestDist = double.MaxValue;
+            hasSnap = false;
+
+            foreach (var info in contours)
+            {
+                var closest = info.Shape.ClosestPointTo(localPt, out var entity);
+                var dist = closest.DistanceTo(localPt);
+
+                if (dist < bestDist)
+                {
+                    bestDist = dist;
+                    snapPoint = closest;
+                    snapEntity = entity;
+                    snapContourType = info.ContourType;
+                    snapNormal = ContourCuttingStrategy.ComputeNormal(closest, entity, info.ContourType);
+                    hasSnap = true;
+                }
+            }
+
+            plateView.Invalidate();
+        }
+
+        private void OnMouseDown(object sender, MouseEventArgs e)
+        {
+            if (e.Button == MouseButtons.Left)
+            {
+                if (selectedPart == null)
+                {
+                    // First click: select a part
+                    SelectPartAtCursor();
+                }
+                else if (hasSnap)
+                {
+                    // Second click: commit lead-in at snap point
+                    CommitLeadIn();
+                }
+            }
+            else if (e.Button == MouseButtons.Right)
+            {
+                if (selectedPart != null && selectedPart.HasManualLeadIns)
+                    ShowContextMenu(e.Location);
+                else
+                    DeselectPart();
+            }
+        }
+
+        private void OnKeyDown(object sender, KeyEventArgs e)
+        {
+            if (e.KeyCode == Keys.Escape)
+            {
+                if (selectedPart != null)
+                    DeselectPart();
+                else
+                    plateView.SetAction(typeof(ActionSelect));
+            }
+        }
+
+        private void OnPaint(object sender, PaintEventArgs e)
+        {
+            if (!hasSnap || selectedPart == null)
+                return;
+
+            var parameters = plateView.Plate?.CuttingParameters;
+            if (parameters == null)
+                return;
+
+            // Transform snap point from local part space to world space
+            var worldSnap = TransformToWorld(snapPoint);
+
+            // Get the appropriate lead-in for this contour type
+            var leadIn = SelectLeadIn(parameters, snapContourType);
+            if (leadIn == null)
+                return;
+
+            // Get the pierce point (in local space)
+            var piercePoint = leadIn.GetPiercePoint(snapPoint, snapNormal);
+            var worldPierce = TransformToWorld(piercePoint);
+
+            var g = e.Graphics;
+            var oldSmooth = g.SmoothingMode;
+            g.SmoothingMode = SmoothingMode.AntiAlias;
+
+            // Draw the lead-in preview as a line from pierce point to contour point
+            var pt1 = plateView.PointWorldToGraph(worldPierce);
+            var pt2 = plateView.PointWorldToGraph(worldSnap);
+
+            using var pen = new Pen(Color.Yellow, 2.0f / plateView.ViewScale);
+            g.DrawLine(pen, pt1, pt2);
+
+            // Draw a small circle at the pierce point
+            var radius = 3.0f / plateView.ViewScale;
+            g.FillEllipse(Brushes.Yellow, pt1.X - radius, pt1.Y - radius, radius * 2, radius * 2);
+
+            // Draw a small circle at the contour start point
+            g.FillEllipse(Brushes.Lime, pt2.X - radius, pt2.Y - radius, radius * 2, radius * 2);
+
+            g.SmoothingMode = oldSmooth;
+        }
+
+        private void SelectPartAtCursor()
+        {
+            var layoutPart = plateView.GetPartAtPoint(plateView.CurrentPoint);
+            if (layoutPart == null)
+                return;
+
+            var part = layoutPart.BasePart;
+
+            // Don't allow lead-in placement on cut-off parts
+            if (part.BaseDrawing.IsCutOff)
+                return;
+
+            // If part already has locked lead-ins, don't allow re-placement
+            if (part.LeadInsLocked)
+                return;
+
+            selectedLayoutPart = layoutPart;
+            selectedPart = part;
+
+            // Build contour info from the part's program geometry
+            BuildContourInfo();
+
+            // Highlight the selected part
+            layoutPart.IsSelected = true;
+            plateView.Invalidate();
+        }
+
+        private void BuildContourInfo()
+        {
+            // Get a clean program (no lead-ins) in the part's current rotated space.
+            // If the part has manual lead-ins, rebuild from base drawing + rotation.
+            // Otherwise the current Program is already clean and rotated.
+            CNC.Program cleanProgram;
+
+            if (selectedPart.HasManualLeadIns)
+            {
+                cleanProgram = selectedPart.BaseDrawing.Program.Clone() as CNC.Program;
+                if (!OpenNest.Math.Tolerance.IsEqualTo(selectedPart.Rotation, 0))
+                    cleanProgram.Rotate(selectedPart.Rotation);
+            }
+            else
+            {
+                cleanProgram = selectedPart.Program;
+            }
+
+            var entities = ConvertProgram.ToGeometry(cleanProgram);
+            profile = new ShapeProfile(entities);
+
+            contours = new List<ShapeInfo>();
+
+            // Perimeter is always External
+            if (profile.Perimeter != null)
+            {
+                contours.Add(new ShapeInfo
+                {
+                    Shape = profile.Perimeter,
+                    ContourType = ContourType.External
+                });
+            }
+
+            // Cutouts
+            foreach (var cutout in profile.Cutouts)
+            {
+                contours.Add(new ShapeInfo
+                {
+                    Shape = cutout,
+                    ContourType = ContourCuttingStrategy.DetectContourType(cutout)
+                });
+            }
+        }
+
+        private void CommitLeadIn()
+        {
+            var parameters = plateView.Plate?.CuttingParameters;
+            if (parameters == null)
+                return;
+
+            // Remove any existing lead-ins first
+            if (selectedPart.HasManualLeadIns)
+                selectedPart.RemoveLeadIns();
+
+            // Apply lead-ins using the snap point as the approach point.
+            // snapPoint is in the program's local coordinate space (rotated, not offset),
+            // which is what Part.ApplyLeadIns expects.
+            selectedPart.ApplyLeadIns(parameters, snapPoint);
+            selectedPart.LeadInsLocked = true;
+
+            // Rebuild the layout part's graphics
+            selectedLayoutPart.IsDirty = true;
+            selectedLayoutPart.Update();
+
+            // Deselect and reset
+            DeselectPart();
+            plateView.Invalidate();
+        }
+
+        private void DeselectPart()
+        {
+            if (selectedLayoutPart != null)
+            {
+                selectedLayoutPart.IsSelected = false;
+                selectedLayoutPart = null;
+            }
+
+            selectedPart = null;
+            profile = null;
+            contours = null;
+            hasSnap = false;
+            plateView.Invalidate();
+        }
+
+        private void ShowContextMenu(Point location)
+        {
+            contextMenu?.Dispose();
+            contextMenu = new ContextMenuStrip();
+
+            var removeItem = new ToolStripMenuItem("Remove All Lead-ins");
+            removeItem.Click += (s, e) =>
+            {
+                selectedPart.RemoveLeadIns();
+                selectedLayoutPart.IsDirty = true;
+                selectedLayoutPart.Update();
+                DeselectPart();
+                plateView.Invalidate();
+            };
+
+            contextMenu.Items.Add(removeItem);
+            contextMenu.Show(plateView, location);
+        }
+
+        private Vector TransformToWorld(Vector localPt)
+        {
+            // The contours are already in rotated local space (we rotated the program
+            // before building the profile), so just add the part location offset
+            return new Vector(localPt.X + selectedPart.Location.X,
+                              localPt.Y + selectedPart.Location.Y);
+        }
+
+        private static LeadIn SelectLeadIn(CuttingParameters parameters, ContourType contourType)
+        {
+            return contourType switch
+            {
+                ContourType.ArcCircle => parameters.ArcCircleLeadIn ?? parameters.InternalLeadIn,
+                ContourType.Internal => parameters.InternalLeadIn,
+                _ => parameters.ExternalLeadIn
+            };
+        }
+
+        private class ShapeInfo
+        {
+            public Shape Shape { get; set; }
+            public ContourType ContourType { get; set; }
+        }
+    }
+}

OpenNest/Forms/CuttingParametersForm.Designer.cs

@@ -0,0 +1,156 @@
+namespace OpenNest.Forms
+{
+    partial class CuttingParametersForm
+    {
+        /// <summary>
+        /// Required designer variable.
+        /// </summary>
+        private System.ComponentModel.IContainer components = null;
+
+        /// <summary>
+        /// Clean up any resources being used.
+        /// </summary>
+        /// <param name="disposing">true if managed resources should be disposed; otherwise, false.</param>
+        protected override void Dispose(bool disposing)
+        {
+            if (disposing && (components != null))
+            {
+                components.Dispose();
+            }
+            base.Dispose(disposing);
+        }
+
+        #region Windows Form Designer generated code
+
+        /// <summary>
+        /// Required method for Designer support - do not modify
+        /// the contents of this method with the code editor.
+        /// </summary>
+        private void InitializeComponent()
+        {
+            this.tabControl = new System.Windows.Forms.TabControl();
+            this.tabExternal = new System.Windows.Forms.TabPage();
+            this.tabInternal = new System.Windows.Forms.TabPage();
+            this.tabArcCircle = new System.Windows.Forms.TabPage();
+            this.acceptButton = new System.Windows.Forms.Button();
+            this.cancelButton = new System.Windows.Forms.Button();
+            this.bottomPanel = new OpenNest.Controls.BottomPanel();
+            this.tabControl.SuspendLayout();
+            this.bottomPanel.SuspendLayout();
+            this.SuspendLayout();
+            //
+            // tabControl
+            //
+            this.tabControl.Controls.Add(this.tabExternal);
+            this.tabControl.Controls.Add(this.tabInternal);
+            this.tabControl.Controls.Add(this.tabArcCircle);
+            this.tabControl.Dock = System.Windows.Forms.DockStyle.Top;
+            this.tabControl.Location = new System.Drawing.Point(0, 0);
+            this.tabControl.Margin = new System.Windows.Forms.Padding(4);
+            this.tabControl.Name = "tabControl";
+            this.tabControl.SelectedIndex = 0;
+            this.tabControl.Size = new System.Drawing.Size(380, 348);
+            this.tabControl.TabIndex = 0;
+            //
+            // tabExternal
+            //
+            this.tabExternal.Location = new System.Drawing.Point(4, 25);
+            this.tabExternal.Margin = new System.Windows.Forms.Padding(4);
+            this.tabExternal.Name = "tabExternal";
+            this.tabExternal.Padding = new System.Windows.Forms.Padding(8);
+            this.tabExternal.Size = new System.Drawing.Size(372, 319);
+            this.tabExternal.TabIndex = 0;
+            this.tabExternal.Text = "External";
+            this.tabExternal.UseVisualStyleBackColor = true;
+            //
+            // tabInternal
+            //
+            this.tabInternal.Location = new System.Drawing.Point(4, 25);
+            this.tabInternal.Margin = new System.Windows.Forms.Padding(4);
+            this.tabInternal.Name = "tabInternal";
+            this.tabInternal.Padding = new System.Windows.Forms.Padding(8);
+            this.tabInternal.Size = new System.Drawing.Size(372, 319);
+            this.tabInternal.TabIndex = 1;
+            this.tabInternal.Text = "Internal";
+            this.tabInternal.UseVisualStyleBackColor = true;
+            //
+            // tabArcCircle
+            //
+            this.tabArcCircle.Location = new System.Drawing.Point(4, 25);
+            this.tabArcCircle.Margin = new System.Windows.Forms.Padding(4);
+            this.tabArcCircle.Name = "tabArcCircle";
+            this.tabArcCircle.Padding = new System.Windows.Forms.Padding(8);
+            this.tabArcCircle.Size = new System.Drawing.Size(372, 319);
+            this.tabArcCircle.TabIndex = 2;
+            this.tabArcCircle.Text = "Arc / Circle";
+            this.tabArcCircle.UseVisualStyleBackColor = true;
+            //
+            // acceptButton
+            //
+            this.acceptButton.Anchor = ((System.Windows.Forms.AnchorStyles)((System.Windows.Forms.AnchorStyles.Bottom | System.Windows.Forms.AnchorStyles.Right)));
+            this.acceptButton.DialogResult = System.Windows.Forms.DialogResult.OK;
+            this.acceptButton.Location = new System.Drawing.Point(165, 11);
+            this.acceptButton.Margin = new System.Windows.Forms.Padding(4);
+            this.acceptButton.Name = "acceptButton";
+            this.acceptButton.Size = new System.Drawing.Size(90, 28);
+            this.acceptButton.TabIndex = 8;
+            this.acceptButton.Text = "OK";
+            this.acceptButton.UseVisualStyleBackColor = true;
+            //
+            // cancelButton
+            //
+            this.cancelButton.Anchor = ((System.Windows.Forms.AnchorStyles)((System.Windows.Forms.AnchorStyles.Bottom | System.Windows.Forms.AnchorStyles.Right)));
+            this.cancelButton.DialogResult = System.Windows.Forms.DialogResult.Cancel;
+            this.cancelButton.Location = new System.Drawing.Point(263, 11);
+            this.cancelButton.Margin = new System.Windows.Forms.Padding(4);
+            this.cancelButton.Name = "cancelButton";
+            this.cancelButton.Size = new System.Drawing.Size(90, 28);
+            this.cancelButton.TabIndex = 9;
+            this.cancelButton.Text = "Cancel";
+            this.cancelButton.UseVisualStyleBackColor = true;
+            //
+            // bottomPanel
+            //
+            this.bottomPanel.Controls.Add(this.acceptButton);
+            this.bottomPanel.Controls.Add(this.cancelButton);
+            this.bottomPanel.Dock = System.Windows.Forms.DockStyle.Bottom;
+            this.bottomPanel.Location = new System.Drawing.Point(0, 406);
+            this.bottomPanel.Name = "bottomPanel";
+            this.bottomPanel.Size = new System.Drawing.Size(380, 50);
+            this.bottomPanel.TabIndex = 1;
+            //
+            // CuttingParametersForm
+            //
+            this.AcceptButton = this.acceptButton;
+            this.AutoScaleDimensions = new System.Drawing.SizeF(8F, 16F);
+            this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
+            this.CancelButton = this.cancelButton;
+            this.ClientSize = new System.Drawing.Size(380, 456);
+            this.Controls.Add(this.tabControl);
+            this.Controls.Add(this.bottomPanel);
+            this.Font = new System.Drawing.Font("Microsoft Sans Serif", 9.75F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((byte)(0)));
+            this.FormBorderStyle = System.Windows.Forms.FormBorderStyle.FixedDialog;
+            this.Margin = new System.Windows.Forms.Padding(4);
+            this.MaximizeBox = false;
+            this.MinimizeBox = false;
+            this.Name = "CuttingParametersForm";
+            this.ShowIcon = false;
+            this.ShowInTaskbar = false;
+            this.StartPosition = System.Windows.Forms.FormStartPosition.CenterParent;
+            this.Text = "Cutting Parameters";
+            this.tabControl.ResumeLayout(false);
+            this.bottomPanel.ResumeLayout(false);
+            this.ResumeLayout(false);
+        }
+
+        #endregion
+
+        private System.Windows.Forms.TabControl tabControl;
+        private System.Windows.Forms.TabPage tabExternal;
+        private System.Windows.Forms.TabPage tabInternal;
+        private System.Windows.Forms.TabPage tabArcCircle;
+        private Controls.BottomPanel bottomPanel;
+        private System.Windows.Forms.Button acceptButton;
+        private System.Windows.Forms.Button cancelButton;
+    }
+}

OpenNest/Forms/CuttingParametersForm.cs

@@ -0,0 +1,476 @@
+using OpenNest.CNC.CuttingStrategy;
+using System;
+using System.Windows.Forms;
+
+namespace OpenNest.Forms
+{
+    public partial class CuttingParametersForm : Form
+    {
+        private static readonly string[] LeadInTypes =
+            { "None", "Line", "Arc", "Line + Arc", "Clean Hole", "Line + Line" };
+
+        private static readonly string[] LeadOutTypes =
+            { "None", "Line", "Arc", "Microtab" };
+
+        private ComboBox cboExternalLeadIn, cboExternalLeadOut;
+        private ComboBox cboInternalLeadIn, cboInternalLeadOut;
+        private ComboBox cboArcCircleLeadIn, cboArcCircleLeadOut;
+
+        private Panel pnlExternalLeadIn, pnlExternalLeadOut;
+        private Panel pnlInternalLeadIn, pnlInternalLeadOut;
+        private Panel pnlArcCircleLeadIn, pnlArcCircleLeadOut;
+
+        private CheckBox chkTabsEnabled;
+        private NumericUpDown nudTabWidth;
+
+        public CuttingParameters Parameters { get; set; } = new CuttingParameters();
+
+        public CuttingParametersForm()
+        {
+            InitializeComponent();
+
+            SetupTab(tabExternal,
+                out cboExternalLeadIn, out pnlExternalLeadIn,
+                out cboExternalLeadOut, out pnlExternalLeadOut);
+            SetupTab(tabInternal,
+                out cboInternalLeadIn, out pnlInternalLeadIn,
+                out cboInternalLeadOut, out pnlInternalLeadOut);
+            SetupTab(tabArcCircle,
+                out cboArcCircleLeadIn, out pnlArcCircleLeadIn,
+                out cboArcCircleLeadOut, out pnlArcCircleLeadOut);
+
+            SetupTabsSection();
+            PopulateDropdowns();
+
+            cboExternalLeadIn.SelectedIndexChanged += OnLeadInTypeChanged;
+            cboInternalLeadIn.SelectedIndexChanged += OnLeadInTypeChanged;
+            cboArcCircleLeadIn.SelectedIndexChanged += OnLeadInTypeChanged;
+
+            cboExternalLeadOut.SelectedIndexChanged += OnLeadOutTypeChanged;
+            cboInternalLeadOut.SelectedIndexChanged += OnLeadOutTypeChanged;
+            cboArcCircleLeadOut.SelectedIndexChanged += OnLeadOutTypeChanged;
+        }
+
+        protected override void OnLoad(EventArgs e)
+        {
+            base.OnLoad(e);
+            LoadFromParameters(Parameters);
+        }
+
+        private static void SetupTab(TabPage tab,
+            out ComboBox leadInCombo, out Panel leadInPanel,
+            out ComboBox leadOutCombo, out Panel leadOutPanel)
+        {
+            var grpLeadIn = new GroupBox
+            {
+                Text = "Lead-In",
+                Location = new System.Drawing.Point(4, 4),
+                Size = new System.Drawing.Size(364, 168)
+            };
+            tab.Controls.Add(grpLeadIn);
+
+            grpLeadIn.Controls.Add(new Label
+            {
+                Text = "Type:",
+                Location = new System.Drawing.Point(8, 22),
+                AutoSize = true
+            });
+
+            leadInCombo = new ComboBox
+            {
+                DropDownStyle = ComboBoxStyle.DropDownList,
+                Location = new System.Drawing.Point(90, 19),
+                Size = new System.Drawing.Size(250, 24)
+            };
+            grpLeadIn.Controls.Add(leadInCombo);
+
+            leadInPanel = new Panel
+            {
+                Location = new System.Drawing.Point(8, 48),
+                Size = new System.Drawing.Size(340, 112),
+                AutoScroll = true
+            };
+            grpLeadIn.Controls.Add(leadInPanel);
+
+            var grpLeadOut = new GroupBox
+            {
+                Text = "Lead-Out",
+                Location = new System.Drawing.Point(4, 176),
+                Size = new System.Drawing.Size(364, 132)
+            };
+            tab.Controls.Add(grpLeadOut);
+
+            grpLeadOut.Controls.Add(new Label
+            {
+                Text = "Type:",
+                Location = new System.Drawing.Point(8, 22),
+                AutoSize = true
+            });
+
+            leadOutCombo = new ComboBox
+            {
+                DropDownStyle = ComboBoxStyle.DropDownList,
+                Location = new System.Drawing.Point(90, 19),
+                Size = new System.Drawing.Size(250, 24)
+            };
+            grpLeadOut.Controls.Add(leadOutCombo);
+
+            leadOutPanel = new Panel
+            {
+                Location = new System.Drawing.Point(8, 48),
+                Size = new System.Drawing.Size(340, 76),
+                AutoScroll = true
+            };
+            grpLeadOut.Controls.Add(leadOutPanel);
+        }
+
+        private void SetupTabsSection()
+        {
+            var grpTabs = new GroupBox
+            {
+                Text = "Tabs",
+                Location = new System.Drawing.Point(4, 350),
+                Size = new System.Drawing.Size(372, 55),
+                Anchor = AnchorStyles.Top | AnchorStyles.Left | AnchorStyles.Right
+            };
+
+            chkTabsEnabled = new CheckBox
+            {
+                Text = "Enable Tabs",
+                Location = new System.Drawing.Point(12, 22),
+                AutoSize = true
+            };
+            chkTabsEnabled.CheckedChanged += (s, e) => nudTabWidth.Enabled = chkTabsEnabled.Checked;
+            grpTabs.Controls.Add(chkTabsEnabled);
+
+            grpTabs.Controls.Add(new Label
+            {
+                Text = "Width:",
+                Location = new System.Drawing.Point(160, 23),
+                AutoSize = true
+            });
+
+            nudTabWidth = new NumericUpDown
+            {
+                Location = new System.Drawing.Point(215, 20),
+                Size = new System.Drawing.Size(100, 22),
+                DecimalPlaces = 4,
+                Increment = 0.0625m,
+                Minimum = 0,
+                Maximum = 9999,
+                Value = 0.25m,
+                Enabled = false
+            };
+            grpTabs.Controls.Add(nudTabWidth);
+
+            Controls.Add(grpTabs);
+        }
+
+        private void PopulateDropdowns()
+        {
+            foreach (var combo in new[] { cboExternalLeadIn, cboInternalLeadIn, cboArcCircleLeadIn })
+            {
+                combo.Items.AddRange(LeadInTypes);
+                combo.SelectedIndex = 0;
+            }
+
+            foreach (var combo in new[] { cboExternalLeadOut, cboInternalLeadOut, cboArcCircleLeadOut })
+            {
+                combo.Items.AddRange(LeadOutTypes);
+                combo.SelectedIndex = 0;
+            }
+        }
+
+        private void OnLeadInTypeChanged(object sender, EventArgs e)
+        {
+            var combo = (ComboBox)sender;
+            var panel = GetLeadInPanel(combo);
+            if (panel != null)
+                BuildLeadInParamControls(panel, combo.SelectedIndex);
+        }
+
+        private void OnLeadOutTypeChanged(object sender, EventArgs e)
+        {
+            var combo = (ComboBox)sender;
+            var panel = GetLeadOutPanel(combo);
+            if (panel != null)
+                BuildLeadOutParamControls(panel, combo.SelectedIndex);
+        }
+
+        private Panel GetLeadInPanel(ComboBox combo)
+        {
+            if (combo == cboExternalLeadIn) return pnlExternalLeadIn;
+            if (combo == cboInternalLeadIn) return pnlInternalLeadIn;
+            if (combo == cboArcCircleLeadIn) return pnlArcCircleLeadIn;
+            return null;
+        }
+
+        private Panel GetLeadOutPanel(ComboBox combo)
+        {
+            if (combo == cboExternalLeadOut) return pnlExternalLeadOut;
+            if (combo == cboInternalLeadOut) return pnlInternalLeadOut;
+            if (combo == cboArcCircleLeadOut) return pnlArcCircleLeadOut;
+            return null;
+        }
+
+        private static void BuildLeadInParamControls(Panel panel, int typeIndex)
+        {
+            panel.Controls.Clear();
+            var y = 0;
+
+            switch (typeIndex)
+            {
+                case 1: // Line
+                    AddNumericField(panel, "Length:", 0.25, ref y, "Length");
+                    AddNumericField(panel, "Approach Angle:", 90, ref y, "ApproachAngle");
+                    break;
+                case 2: // Arc
+                    AddNumericField(panel, "Radius:", 0.25, ref y, "Radius");
+                    break;
+                case 3: // Line + Arc
+                    AddNumericField(panel, "Line Length:", 0.25, ref y, "LineLength");
+                    AddNumericField(panel, "Arc Radius:", 0.125, ref y, "ArcRadius");
+                    AddNumericField(panel, "Approach Angle:", 135, ref y, "ApproachAngle");
+                    break;
+                case 4: // Clean Hole
+                    AddNumericField(panel, "Line Length:", 0.25, ref y, "LineLength");
+                    AddNumericField(panel, "Arc Radius:", 0.125, ref y, "ArcRadius");
+                    AddNumericField(panel, "Kerf:", 0.06, ref y, "Kerf");
+                    break;
+                case 5: // Line + Line
+                    AddNumericField(panel, "Length 1:", 0.25, ref y, "Length1");
+                    AddNumericField(panel, "Angle 1:", 90, ref y, "Angle1");
+                    AddNumericField(panel, "Length 2:", 0.25, ref y, "Length2");
+                    AddNumericField(panel, "Angle 2:", 90, ref y, "Angle2");
+                    break;
+            }
+        }
+
+        private static void BuildLeadOutParamControls(Panel panel, int typeIndex)
+        {
+            panel.Controls.Clear();
+            var y = 0;
+
+            switch (typeIndex)
+            {
+                case 1: // Line
+                    AddNumericField(panel, "Length:", 0.25, ref y, "Length");
+                    AddNumericField(panel, "Approach Angle:", 90, ref y, "ApproachAngle");
+                    break;
+                case 2: // Arc
+                    AddNumericField(panel, "Radius:", 0.25, ref y, "Radius");
+                    break;
+                case 3: // Microtab
+                    AddNumericField(panel, "Gap Size:", 0.06, ref y, "GapSize");
+                    break;
+            }
+        }
+
+        private static void AddNumericField(Panel panel, string label, double defaultValue,
+            ref int y, string tag)
+        {
+            panel.Controls.Add(new Label
+            {
+                Text = label,
+                Location = new System.Drawing.Point(0, y + 3),
+                AutoSize = true
+            });
+
+            panel.Controls.Add(new NumericUpDown
+            {
+                Location = new System.Drawing.Point(130, y),
+                Size = new System.Drawing.Size(120, 22),
+                DecimalPlaces = 4,
+                Increment = 0.0625m,
+                Minimum = 0,
+                Maximum = 9999,
+                Value = (decimal)defaultValue,
+                Tag = tag
+            });
+
+            y += 30;
+        }
+
+        private void LoadFromParameters(CuttingParameters p)
+        {
+            LoadLeadIn(cboExternalLeadIn, pnlExternalLeadIn, p.ExternalLeadIn);
+            LoadLeadOut(cboExternalLeadOut, pnlExternalLeadOut, p.ExternalLeadOut);
+
+            LoadLeadIn(cboInternalLeadIn, pnlInternalLeadIn, p.InternalLeadIn);
+            LoadLeadOut(cboInternalLeadOut, pnlInternalLeadOut, p.InternalLeadOut);
+
+            LoadLeadIn(cboArcCircleLeadIn, pnlArcCircleLeadIn, p.ArcCircleLeadIn);
+            LoadLeadOut(cboArcCircleLeadOut, pnlArcCircleLeadOut, p.ArcCircleLeadOut);
+
+            chkTabsEnabled.Checked = p.TabsEnabled;
+            if (p.TabConfig != null)
+                nudTabWidth.Value = (decimal)p.TabConfig.Size;
+        }
+
+        private static void LoadLeadIn(ComboBox combo, Panel panel, LeadIn leadIn)
+        {
+            switch (leadIn)
+            {
+                case LineLeadIn line:
+                    combo.SelectedIndex = 1;
+                    SetParam(panel, "Length", line.Length);
+                    SetParam(panel, "ApproachAngle", line.ApproachAngle);
+                    break;
+                case ArcLeadIn arc:
+                    combo.SelectedIndex = 2;
+                    SetParam(panel, "Radius", arc.Radius);
+                    break;
+                case LineArcLeadIn lineArc:
+                    combo.SelectedIndex = 3;
+                    SetParam(panel, "LineLength", lineArc.LineLength);
+                    SetParam(panel, "ArcRadius", lineArc.ArcRadius);
+                    SetParam(panel, "ApproachAngle", lineArc.ApproachAngle);
+                    break;
+                case CleanHoleLeadIn cleanHole:
+                    combo.SelectedIndex = 4;
+                    SetParam(panel, "LineLength", cleanHole.LineLength);
+                    SetParam(panel, "ArcRadius", cleanHole.ArcRadius);
+                    SetParam(panel, "Kerf", cleanHole.Kerf);
+                    break;
+                case LineLineLeadIn lineLine:
+                    combo.SelectedIndex = 5;
+                    SetParam(panel, "Length1", lineLine.Length1);
+                    SetParam(panel, "Angle1", lineLine.ApproachAngle1);
+                    SetParam(panel, "Length2", lineLine.Length2);
+                    SetParam(panel, "Angle2", lineLine.ApproachAngle2);
+                    break;
+                default:
+                    combo.SelectedIndex = 0;
+                    break;
+            }
+        }
+
+        private static void LoadLeadOut(ComboBox combo, Panel panel, LeadOut leadOut)
+        {
+            switch (leadOut)
+            {
+                case LineLeadOut line:
+                    combo.SelectedIndex = 1;
+                    SetParam(panel, "Length", line.Length);
+                    SetParam(panel, "ApproachAngle", line.ApproachAngle);
+                    break;
+                case ArcLeadOut arc:
+                    combo.SelectedIndex = 2;
+                    SetParam(panel, "Radius", arc.Radius);
+                    break;
+                case MicrotabLeadOut microtab:
+                    combo.SelectedIndex = 3;
+                    SetParam(panel, "GapSize", microtab.GapSize);
+                    break;
+                default:
+                    combo.SelectedIndex = 0;
+                    break;
+            }
+        }
+
+        public CuttingParameters BuildParameters()
+        {
+            var p = new CuttingParameters
+            {
+                ExternalLeadIn = BuildLeadIn(cboExternalLeadIn, pnlExternalLeadIn),
+                ExternalLeadOut = BuildLeadOut(cboExternalLeadOut, pnlExternalLeadOut),
+                InternalLeadIn = BuildLeadIn(cboInternalLeadIn, pnlInternalLeadIn),
+                InternalLeadOut = BuildLeadOut(cboInternalLeadOut, pnlInternalLeadOut),
+                ArcCircleLeadIn = BuildLeadIn(cboArcCircleLeadIn, pnlArcCircleLeadIn),
+                ArcCircleLeadOut = BuildLeadOut(cboArcCircleLeadOut, pnlArcCircleLeadOut),
+                TabsEnabled = chkTabsEnabled.Checked,
+                TabConfig = new NormalTab { Size = (double)nudTabWidth.Value }
+            };
+            return p;
+        }
+
+        private static LeadIn BuildLeadIn(ComboBox combo, Panel panel)
+        {
+            switch (combo.SelectedIndex)
+            {
+                case 1:
+                    return new LineLeadIn
+                    {
+                        Length = GetParam(panel, "Length", 0.25),
+                        ApproachAngle = GetParam(panel, "ApproachAngle", 90)
+                    };
+                case 2:
+                    return new ArcLeadIn
+                    {
+                        Radius = GetParam(panel, "Radius", 0.25)
+                    };
+                case 3:
+                    return new LineArcLeadIn
+                    {
+                        LineLength = GetParam(panel, "LineLength", 0.25),
+                        ArcRadius = GetParam(panel, "ArcRadius", 0.125),
+                        ApproachAngle = GetParam(panel, "ApproachAngle", 135)
+                    };
+                case 4:
+                    return new CleanHoleLeadIn
+                    {
+                        LineLength = GetParam(panel, "LineLength", 0.25),
+                        ArcRadius = GetParam(panel, "ArcRadius", 0.125),
+                        Kerf = GetParam(panel, "Kerf", 0.06)
+                    };
+                case 5:
+                    return new LineLineLeadIn
+                    {
+                        Length1 = GetParam(panel, "Length1", 0.25),
+                        ApproachAngle1 = GetParam(panel, "Angle1", 90),
+                        Length2 = GetParam(panel, "Length2", 0.25),
+                        ApproachAngle2 = GetParam(panel, "Angle2", 90)
+                    };
+                default:
+                    return new NoLeadIn();
+            }
+        }
+
+        private static LeadOut BuildLeadOut(ComboBox combo, Panel panel)
+        {
+            switch (combo.SelectedIndex)
+            {
+                case 1:
+                    return new LineLeadOut
+                    {
+                        Length = GetParam(panel, "Length", 0.25),
+                        ApproachAngle = GetParam(panel, "ApproachAngle", 90)
+                    };
+                case 2:
+                    return new ArcLeadOut
+                    {
+                        Radius = GetParam(panel, "Radius", 0.25)
+                    };
+                case 3:
+                    return new MicrotabLeadOut
+                    {
+                        GapSize = GetParam(panel, "GapSize", 0.06)
+                    };
+                default:
+                    return new NoLeadOut();
+            }
+        }
+
+        private static void SetParam(Panel panel, string tag, double value)
+        {
+            foreach (Control c in panel.Controls)
+            {
+                if (c is NumericUpDown nud && (string)nud.Tag == tag)
+                {
+                    nud.Value = (decimal)value;
+                    return;
+                }
+            }
+        }
+
+        private static double GetParam(Panel panel, string tag, double defaultValue)
+        {
+            foreach (Control c in panel.Controls)
+            {
+                if (c is NumericUpDown nud && (string)nud.Tag == tag)
+                    return (double)nud.Value;
+            }
+            return defaultValue;
+        }
+    }
+}

OpenNest/Forms/EditNestForm.Designer.cs

@@ -38,6 +38,8 @@
             this.qtyColumn = ((System.Windows.Forms.ColumnHeader)(new System.Windows.Forms.ColumnHeader()));
             this.toolStrip1 = new System.Windows.Forms.ToolStrip();
             this.toolStripButton1 = new System.Windows.Forms.ToolStripButton();
+            this.btnAssignLeadIns = new System.Windows.Forms.ToolStripButton();
+            this.btnPlaceLeadIn = new System.Windows.Forms.ToolStripButton();
             this.tabPage2 = new System.Windows.Forms.TabPage();
             this.drawingListBox1 = new OpenNest.Controls.DrawingListBox();
             this.toolStrip2 = new System.Windows.Forms.ToolStrip();
@@ -133,7 +135,9 @@
             this.toolStrip1.GripStyle = System.Windows.Forms.ToolStripGripStyle.Hidden;
             this.toolStrip1.ImageScalingSize = new System.Drawing.Size(20, 20);
             this.toolStrip1.Items.AddRange(new System.Windows.Forms.ToolStripItem[] {
-            this.toolStripButton1});
+            this.toolStripButton1,
+            this.btnAssignLeadIns,
+            this.btnPlaceLeadIn});
             this.toolStrip1.Location = new System.Drawing.Point(3, 3);
             this.toolStrip1.Name = "toolStrip1";
             this.toolStrip1.Size = new System.Drawing.Size(227, 31);
@@ -151,7 +155,25 @@
             this.toolStripButton1.Size = new System.Drawing.Size(38, 28);
             this.toolStripButton1.Text = "Calculate Cut Time";
             this.toolStripButton1.Click += new System.EventHandler(this.CalculateSelectedPlateCutTime_Click);
-            // 
+            //
+            // btnAssignLeadIns
+            //
+            this.btnAssignLeadIns.DisplayStyle = System.Windows.Forms.ToolStripItemDisplayStyle.Text;
+            this.btnAssignLeadIns.ImageTransparentColor = System.Drawing.Color.Magenta;
+            this.btnAssignLeadIns.Name = "btnAssignLeadIns";
+            this.btnAssignLeadIns.Size = new System.Drawing.Size(96, 28);
+            this.btnAssignLeadIns.Text = "Assign Lead-ins";
+            this.btnAssignLeadIns.Click += new System.EventHandler(this.AssignLeadIns_Click);
+            //
+            // btnPlaceLeadIn
+            //
+            this.btnPlaceLeadIn.DisplayStyle = System.Windows.Forms.ToolStripItemDisplayStyle.Text;
+            this.btnPlaceLeadIn.ImageTransparentColor = System.Drawing.Color.Magenta;
+            this.btnPlaceLeadIn.Name = "btnPlaceLeadIn";
+            this.btnPlaceLeadIn.Size = new System.Drawing.Size(90, 28);
+            this.btnPlaceLeadIn.Text = "Place Lead-in";
+            this.btnPlaceLeadIn.Click += new System.EventHandler(this.PlaceLeadIn_Click);
+            //
             // tabPage2
             // 
             this.tabPage2.Controls.Add(this.drawingListBox1);
@@ -266,5 +288,7 @@
         private System.Windows.Forms.ToolStripButton toolStripButton2;
         private System.Windows.Forms.ToolStripSeparator toolStripSeparator1;
         private System.Windows.Forms.ToolStripButton toolStripButton3;
+        private System.Windows.Forms.ToolStripButton btnAssignLeadIns;
+        private System.Windows.Forms.ToolStripButton btnPlaceLeadIn;
     }
 }

OpenNest/Forms/EditNestForm.cs

@@ -2,6 +2,7 @@
 using OpenNest.CNC.CuttingStrategy;
 using OpenNest.Collections;
 using OpenNest.Controls;
+using OpenNest.Engine;
 using OpenNest.Engine.Sequencing;
 using OpenNest.IO;
 using OpenNest.Math;
@@ -711,6 +712,52 @@ namespace OpenNest.Forms
             CalculateCurrentPlateCutTime();
         }
 
+        private void AssignLeadIns_Click(object sender, EventArgs e)
+        {
+            if (PlateView?.Plate == null)
+                return;
+
+            var plate = PlateView.Plate;
+
+            using var form = new CuttingParametersForm();
+            if (plate.CuttingParameters != null)
+                form.Parameters = plate.CuttingParameters;
+
+            if (form.ShowDialog(this) != DialogResult.OK)
+                return;
+
+            var parameters = form.BuildParameters();
+            plate.CuttingParameters = parameters;
+
+            var assigner = new LeadInAssigner
+            {
+                Sequencer = new LeftSideSequencer()
+            };
+            assigner.Assign(plate);
+
+            PlateView.Invalidate();
+        }
+
+        private void PlaceLeadIn_Click(object sender, EventArgs e)
+        {
+            if (PlateView?.Plate == null)
+                return;
+
+            var plate = PlateView.Plate;
+
+            // Ensure cutting parameters are configured
+            if (plate.CuttingParameters == null)
+            {
+                using var form = new CuttingParametersForm();
+                if (form.ShowDialog(this) != DialogResult.OK)
+                    return;
+
+                plate.CuttingParameters = form.BuildParameters();
+            }
+
+            PlateView.SetAction(typeof(Actions.ActionLeadIn));
+        }
+
         private void ImportDrawings_Click(object sender, EventArgs e)
         {
             Import();

OpenNest/Forms/SequenceForm.Designer.cs

@@ -28,77 +28,75 @@
         /// </summary>
         private void InitializeComponent()
         {
-            this.tableLayoutPanel1 = new System.Windows.Forms.TableLayoutPanel();
-            this.label1 = new System.Windows.Forms.Label();
-            this.numericUpDown1 = new OpenNest.Controls.NumericUpDown();
-            this.tableLayoutPanel1.SuspendLayout();
-            ((System.ComponentModel.ISupportInitialize)(this.numericUpDown1)).BeginInit();
-            this.SuspendLayout();
+            tableLayoutPanel1 = new System.Windows.Forms.TableLayoutPanel();
+            label1 = new System.Windows.Forms.Label();
+            numericUpDown1 = new OpenNest.Controls.NumericUpDown();
+            tableLayoutPanel1.SuspendLayout();
+            ((System.ComponentModel.ISupportInitialize)numericUpDown1).BeginInit();
+            SuspendLayout();
             // 
             // tableLayoutPanel1
             // 
-            this.tableLayoutPanel1.ColumnCount = 2;
-            this.tableLayoutPanel1.ColumnStyles.Add(new System.Windows.Forms.ColumnStyle());
-            this.tableLayoutPanel1.ColumnStyles.Add(new System.Windows.Forms.ColumnStyle(System.Windows.Forms.SizeType.Percent, 100F));
-            this.tableLayoutPanel1.Controls.Add(this.label1, 0, 0);
-            this.tableLayoutPanel1.Controls.Add(this.numericUpDown1, 1, 0);
-            this.tableLayoutPanel1.Dock = System.Windows.Forms.DockStyle.Fill;
-            this.tableLayoutPanel1.Location = new System.Drawing.Point(0, 0);
-            this.tableLayoutPanel1.Name = "tableLayoutPanel1";
-            this.tableLayoutPanel1.RowCount = 1;
-            this.tableLayoutPanel1.RowStyles.Add(new System.Windows.Forms.RowStyle(System.Windows.Forms.SizeType.Percent, 100F));
-            this.tableLayoutPanel1.Size = new System.Drawing.Size(220, 36);
-            this.tableLayoutPanel1.TabIndex = 0;
+            tableLayoutPanel1.ColumnCount = 2;
+            tableLayoutPanel1.ColumnStyles.Add(new System.Windows.Forms.ColumnStyle());
+            tableLayoutPanel1.ColumnStyles.Add(new System.Windows.Forms.ColumnStyle(System.Windows.Forms.SizeType.Percent, 100F));
+            tableLayoutPanel1.Controls.Add(label1, 0, 0);
+            tableLayoutPanel1.Controls.Add(numericUpDown1, 1, 0);
+            tableLayoutPanel1.Dock = System.Windows.Forms.DockStyle.Fill;
+            tableLayoutPanel1.Location = new System.Drawing.Point(0, 0);
+            tableLayoutPanel1.Margin = new System.Windows.Forms.Padding(4, 3, 4, 3);
+            tableLayoutPanel1.Name = "tableLayoutPanel1";
+            tableLayoutPanel1.RowCount = 1;
+            tableLayoutPanel1.RowStyles.Add(new System.Windows.Forms.RowStyle(System.Windows.Forms.SizeType.Percent, 100F));
+            tableLayoutPanel1.Size = new System.Drawing.Size(266, 35);
+            tableLayoutPanel1.TabIndex = 0;
             // 
             // label1
             // 
-            this.label1.Anchor = ((System.Windows.Forms.AnchorStyles)((System.Windows.Forms.AnchorStyles.Left | System.Windows.Forms.AnchorStyles.Right)));
-            this.label1.AutoSize = true;
-            this.label1.Location = new System.Drawing.Point(3, 11);
-            this.label1.Name = "label1";
-            this.label1.Size = new System.Drawing.Size(62, 13);
-            this.label1.TabIndex = 0;
-            this.label1.Text = "Sequence :";
+            label1.Anchor = System.Windows.Forms.AnchorStyles.Left | System.Windows.Forms.AnchorStyles.Right;
+            label1.AutoSize = true;
+            label1.Location = new System.Drawing.Point(4, 10);
+            label1.Margin = new System.Windows.Forms.Padding(4, 0, 4, 0);
+            label1.Name = "label1";
+            label1.Size = new System.Drawing.Size(64, 15);
+            label1.TabIndex = 0;
+            label1.Text = "Sequence :";
             // 
             // numericUpDown1
             // 
-            this.numericUpDown1.Anchor = ((System.Windows.Forms.AnchorStyles)((System.Windows.Forms.AnchorStyles.Left | System.Windows.Forms.AnchorStyles.Right)));
-            this.numericUpDown1.Location = new System.Drawing.Point(71, 8);
-            this.numericUpDown1.Minimum = new decimal(new int[] {
-            1,
-            0,
-            0,
-            0});
-            this.numericUpDown1.Name = "numericUpDown1";
-            this.numericUpDown1.Size = new System.Drawing.Size(146, 20);
-            this.numericUpDown1.TabIndex = 1;
-            this.numericUpDown1.Value = new decimal(new int[] {
-            1,
-            0,
-            0,
-            0});
-            this.numericUpDown1.Leave += new System.EventHandler(this.numericUpDown1_Leave);
+            numericUpDown1.Anchor = System.Windows.Forms.AnchorStyles.Left | System.Windows.Forms.AnchorStyles.Right;
+            numericUpDown1.Location = new System.Drawing.Point(76, 6);
+            numericUpDown1.Margin = new System.Windows.Forms.Padding(4, 3, 4, 3);
+            numericUpDown1.Minimum = new decimal(new int[] { 1, 0, 0, 0 });
+            numericUpDown1.Name = "numericUpDown1";
+            numericUpDown1.Size = new System.Drawing.Size(186, 23);
+            numericUpDown1.Suffix = "";
+            numericUpDown1.TabIndex = 1;
+            numericUpDown1.Value = new decimal(new int[] { 1, 0, 0, 0 });
+            numericUpDown1.Leave += numericUpDown1_Leave;
             // 
             // SequenceForm
             // 
-            this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 13F);
-            this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
-            this.ClientSize = new System.Drawing.Size(220, 36);
-            this.ControlBox = false;
-            this.Controls.Add(this.tableLayoutPanel1);
-            this.FormBorderStyle = System.Windows.Forms.FormBorderStyle.FixedSingle;
-            this.Location = new System.Drawing.Point(100, 100);
-            this.MaximizeBox = false;
-            this.MinimizeBox = false;
-            this.Name = "SequenceForm";
-            this.ShowIcon = false;
-            this.ShowInTaskbar = false;
-            this.StartPosition = System.Windows.Forms.FormStartPosition.Manual;
-            this.Text = "Set Sequence";
-            this.tableLayoutPanel1.ResumeLayout(false);
-            this.tableLayoutPanel1.PerformLayout();
-            ((System.ComponentModel.ISupportInitialize)(this.numericUpDown1)).EndInit();
-            this.ResumeLayout(false);
+            AutoScaleDimensions = new System.Drawing.SizeF(7F, 15F);
+            AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
+            ClientSize = new System.Drawing.Size(266, 35);
+            ControlBox = false;
+            Controls.Add(tableLayoutPanel1);
+            FormBorderStyle = System.Windows.Forms.FormBorderStyle.FixedToolWindow;
+            Location = new System.Drawing.Point(100, 100);
+            Margin = new System.Windows.Forms.Padding(4, 3, 4, 3);
+            MaximizeBox = false;
+            MinimizeBox = false;
+            MinimumSize = new System.Drawing.Size(268, 74);
+            Name = "SequenceForm";
+            ShowIcon = false;
+            ShowInTaskbar = false;
+            StartPosition = System.Windows.Forms.FormStartPosition.Manual;
+            Text = "Set Sequence";
+            tableLayoutPanel1.ResumeLayout(false);
+            tableLayoutPanel1.PerformLayout();
+            ((System.ComponentModel.ISupportInitialize)numericUpDown1).EndInit();
+            ResumeLayout(false);
 
         }
 

OpenNest/Forms/SequenceForm.resx

@@ -1,17 +1,17 @@
 <?xml version="1.0" encoding="utf-8"?>
 <root>
-  <!-- 
-    Microsoft ResX Schema 
-    
+  <!--
+    Microsoft ResX Schema
+
     Version 2.0
-    
-    The primary goals of this format is to allow a simple XML format 
-    that is mostly human readable. The generation and parsing of the 
-    various data types are done through the TypeConverter classes 
+
+    The primary goals of this format is to allow a simple XML format
+    that is mostly human readable. The generation and parsing of the
+    various data types are done through the TypeConverter classes
     associated with the data types.
-    
+
     Example:
-    
+
     ... ado.net/XML headers & schema ...
     <resheader name="resmimetype">text/microsoft-resx</resheader>
     <resheader name="version">2.0</resheader>
@@ -26,36 +26,36 @@
         <value>[base64 mime encoded string representing a byte array form of the .NET Framework object]</value>
         <comment>This is a comment</comment>
     </data>
-                
-    There are any number of "resheader" rows that contain simple 
+
+    There are any number of "resheader" rows that contain simple
     name/value pairs.
-    
-    Each data row contains a name, and value. The row also contains a 
-    type or mimetype. Type corresponds to a .NET class that support 
-    text/value conversion through the TypeConverter architecture. 
-    Classes that don't support this are serialized and stored with the 
+
+    Each data row contains a name, and value. The row also contains a
+    type or mimetype. Type corresponds to a .NET class that support
+    text/value conversion through the TypeConverter architecture.
+    Classes that don't support this are serialized and stored with the
     mimetype set.
-    
-    The mimetype is used for serialized objects, and tells the 
-    ResXResourceReader how to depersist the object. This is currently not 
+
+    The mimetype is used for serialized objects, and tells the
+    ResXResourceReader how to depersist the object. This is currently not
     extensible. For a given mimetype the value must be set accordingly:
-    
-    Note - application/x-microsoft.net.object.binary.base64 is the format 
-    that the ResXResourceWriter will generate, however the reader can 
+
+    Note - application/x-microsoft.net.object.binary.base64 is the format
+    that the ResXResourceWriter will generate, however the reader can
     read any of the formats listed below.
-    
+
     mimetype: application/x-microsoft.net.object.binary.base64
-    value   : The object must be serialized with 
+    value   : The object must be serialized with
             : System.Runtime.Serialization.Formatters.Binary.BinaryFormatter
             : and then encoded with base64 encoding.
-    
+
     mimetype: application/x-microsoft.net.object.soap.base64
-    value   : The object must be serialized with 
+    value   : The object must be serialized with
             : System.Runtime.Serialization.Formatters.Soap.SoapFormatter
             : and then encoded with base64 encoding.
 
     mimetype: application/x-microsoft.net.object.bytearray.base64
-    value   : The object must be serialized into a byte array 
+    value   : The object must be serialized into a byte array
             : using a System.ComponentModel.TypeConverter
             : and then encoded with base64 encoding.
     -->

OpenNest/GraphicsHelper.cs

@@ -85,6 +85,74 @@ namespace OpenNest
             return img;
         }
 
+        public static void GetGraphicsPaths(this Program pgm, Vector origin,
+            out GraphicsPath cutPath, out GraphicsPath leadPath)
+        {
+            cutPath = new GraphicsPath();
+            leadPath = new GraphicsPath();
+            var curpos = origin;
+
+            AddProgramSplit(cutPath, leadPath, pgm, pgm.Mode, ref curpos);
+        }
+
+        private static void AddProgramSplit(GraphicsPath cutPath, GraphicsPath leadPath,
+            Program pgm, Mode mode, ref Vector curpos)
+        {
+            mode = pgm.Mode;
+
+            for (var i = 0; i < pgm.Length; ++i)
+            {
+                var code = pgm[i];
+
+                switch (code.Type)
+                {
+                    case CodeType.ArcMove:
+                        var arc = (ArcMove)code;
+                        if (arc.Suppressed)
+                        {
+                            var endpt = arc.EndPoint;
+                            if (mode == Mode.Incremental) endpt += curpos;
+                            curpos = endpt;
+                            break;
+                        }
+                        var arcPath = (arc.Layer == LayerType.Leadin || arc.Layer == LayerType.Leadout)
+                            ? leadPath : cutPath;
+                        AddArc(arcPath, arc, mode, ref curpos);
+                        break;
+
+                    case CodeType.LinearMove:
+                        var line = (LinearMove)code;
+                        if (line.Suppressed)
+                        {
+                            var endpt = line.EndPoint;
+                            if (mode == Mode.Incremental) endpt += curpos;
+                            curpos = endpt;
+                            break;
+                        }
+                        var linePath = (line.Layer == LayerType.Leadin || line.Layer == LayerType.Leadout)
+                            ? leadPath : cutPath;
+                        AddLine(linePath, line, mode, ref curpos);
+                        break;
+
+                    case CodeType.RapidMove:
+                        AddLine(cutPath, (RapidMove)code, mode, ref curpos);
+                        break;
+
+                    case CodeType.SubProgramCall:
+                        var tmpmode = mode;
+                        var subpgm = (SubProgramCall)code;
+                        if (subpgm.Program != null)
+                        {
+                            cutPath.StartFigure();
+                            leadPath.StartFigure();
+                            AddProgramSplit(cutPath, leadPath, subpgm.Program, mode, ref curpos);
+                        }
+                        mode = tmpmode;
+                        break;
+                }
+            }
+        }
+
         private static void AddArc(GraphicsPath path, ArcMove arc, Mode mode, ref Vector curpos)
         {
             var endpt = arc.EndPoint;

OpenNest/LayoutPart.cs

@@ -15,6 +15,7 @@ namespace OpenNest
         private static Color selectedColor;
         private static Pen selectedPen;
         private static Brush selectedBrush;
+        private static Pen leadInPen;
 
         private Color color;
         private Brush brush;
@@ -34,6 +35,7 @@ namespace OpenNest
         {
             programIdFont = new Font(SystemFonts.DefaultFont, FontStyle.Bold | FontStyle.Underline);
             SelectedColor = Color.FromArgb(90, 150, 200, 255);
+            leadInPen = new Pen(Color.OrangeRed, 1.5f);
         }
 
         private LayoutPart(Part part)
@@ -52,6 +54,8 @@ namespace OpenNest
 
         public GraphicsPath Path { get; private set; }
 
+        public GraphicsPath LeadInPath { get; private set; }
+
         public Color Color
         {
             get { return color; }
@@ -83,6 +87,9 @@ namespace OpenNest
                 g.FillPath(brush, Path);
                 g.DrawPath(pen, Path);
             }
+
+            if (LeadInPath != null)
+                g.DrawPath(leadInPen, LeadInPath);
         }
 
         public void Draw(Graphics g, string id)
@@ -98,6 +105,9 @@ namespace OpenNest
                 g.DrawPath(pen, Path);
             }
 
+            if (LeadInPath != null)
+                g.DrawPath(leadInPen, LeadInPath);
+
             using var sf = new StringFormat
             {
                 Alignment = StringAlignment.Center,
@@ -138,8 +148,22 @@ namespace OpenNest
 
         public void Update(DrawControl plateView)
         {
-            Path = GraphicsHelper.GetGraphicsPath(BasePart.Program, BasePart.Location);
-            Path.Transform(plateView.Matrix);
+            if (BasePart.HasManualLeadIns)
+            {
+                BasePart.Program.GetGraphicsPaths(BasePart.Location, out var cutPath, out var leadPath);
+                cutPath.Transform(plateView.Matrix);
+                leadPath.Transform(plateView.Matrix);
+                Path = cutPath;
+                LeadInPath?.Dispose();
+                LeadInPath = leadPath;
+            }
+            else
+            {
+                Path = GraphicsHelper.GetGraphicsPath(BasePart.Program, BasePart.Location);
+                Path.Transform(plateView.Matrix);
+                LeadInPath?.Dispose();
+                LeadInPath = null;
+            }
 
             _labelPoint ??= ComputeLabelPoint();
             var rotatedLabel = _labelPoint.Value.Rotate(BasePart.Rotation);