merge: resolve .gitignore conflict, keep both entries

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

.gitignore

@@ -201,3 +201,6 @@ FakesAssemblies/
 
 # Git worktrees
 .worktrees/
+
+# Claude Code
+.claude/

OpenNest.Console/Program.cs

@@ -135,7 +135,7 @@ if (!keepParts)
     plate.Parts.Clear();
 
 Console.WriteLine($"Nest: {nest.Name}");
-Console.WriteLine($"Plate: {plateIndex} ({plate.Size.Width:F1} x {plate.Size.Height:F1}), spacing={plate.PartSpacing:F2}");
+Console.WriteLine($"Plate: {plateIndex} ({plate.Size.Width:F1} x {plate.Size.Length:F1}), spacing={plate.PartSpacing:F2}");
 Console.WriteLine($"Drawing: {drawing.Name}");
 
 if (!keepParts)

OpenNest.Core/CNC/CuttingStrategy/AssignmentParameters.cs

@@ -0,0 +1,9 @@
+namespace OpenNest.CNC.CuttingStrategy
+{
+    public class AssignmentParameters
+    {
+        public SequenceMethod Method { get; set; } = SequenceMethod.Advanced;
+        public string Preference { get; set; } = "ILAT";
+        public double MinGeometryLength { get; set; } = 0.01;
+    }
+}

OpenNest.Core/CNC/CuttingStrategy/ContourCuttingStrategy.cs

@@ -0,0 +1,206 @@
+using System.Collections.Generic;
+using OpenNest.Geometry;
+
+namespace OpenNest.CNC.CuttingStrategy
+{
+    public class ContourCuttingStrategy
+    {
+        public CuttingParameters Parameters { get; set; }
+
+        public Program Apply(Program partProgram, Plate plate)
+        {
+            var exitPoint = GetExitPoint(plate);
+            var entities = partProgram.ToGeometry();
+            var profile = new ShapeProfile(entities);
+
+            // Find closest point on perimeter from exit point
+            var perimeterPoint = profile.Perimeter.ClosestPointTo(exitPoint, out var perimeterEntity);
+
+            // Chain cutouts by nearest-neighbor from perimeter point, then reverse
+            // so farthest cutouts are cut first, nearest-to-perimeter cut last
+            var orderedCutouts = SequenceCutouts(profile.Cutouts, perimeterPoint);
+            orderedCutouts.Reverse();
+
+            // Build output program: cutouts first (farthest to nearest), perimeter last
+            var result = new Program();
+            var currentPoint = exitPoint;
+
+            foreach (var cutout in orderedCutouts)
+            {
+                var contourType = DetectContourType(cutout);
+                var closestPt = cutout.ClosestPointTo(currentPoint, out var entity);
+                var normal = ComputeNormal(closestPt, entity, contourType);
+                var winding = DetermineWinding(cutout);
+
+                var leadIn = SelectLeadIn(contourType);
+                var leadOut = SelectLeadOut(contourType);
+
+                result.Codes.AddRange(leadIn.Generate(closestPt, normal, winding));
+                var reindexed = cutout.ReindexAt(closestPt, entity);
+                result.Codes.AddRange(ConvertShapeToMoves(reindexed, closestPt));
+                // TODO: MicrotabLeadOut — trim last cutting move by GapSize
+                result.Codes.AddRange(leadOut.Generate(closestPt, normal, winding));
+
+                currentPoint = closestPt;
+            }
+
+            // Perimeter last
+            {
+                var perimeterPt = profile.Perimeter.ClosestPointTo(currentPoint, out perimeterEntity);
+                var normal = ComputeNormal(perimeterPt, perimeterEntity, ContourType.External);
+                var winding = DetermineWinding(profile.Perimeter);
+
+                var leadIn = SelectLeadIn(ContourType.External);
+                var leadOut = SelectLeadOut(ContourType.External);
+
+                result.Codes.AddRange(leadIn.Generate(perimeterPt, normal, winding));
+                var reindexed = profile.Perimeter.ReindexAt(perimeterPt, perimeterEntity);
+                result.Codes.AddRange(ConvertShapeToMoves(reindexed, perimeterPt));
+                // TODO: MicrotabLeadOut — trim last cutting move by GapSize
+                result.Codes.AddRange(leadOut.Generate(perimeterPt, normal, winding));
+            }
+
+            return result;
+        }
+
+        private Vector GetExitPoint(Plate plate)
+        {
+            var w = plate.Size.Width;
+            var l = plate.Size.Length;
+
+            return plate.Quadrant switch
+            {
+                1 => new Vector(w, l),         // Q1 origin BottomLeft -> exit TopRight
+                2 => new Vector(0, l),         // Q2 origin BottomRight -> exit TopLeft
+                3 => new Vector(0, 0),         // Q3 origin TopRight -> exit BottomLeft
+                4 => new Vector(w, 0),         // Q4 origin TopLeft -> exit BottomRight
+                _ => new Vector(w, l)
+            };
+        }
+
+        private List<Shape> SequenceCutouts(List<Shape> cutouts, Vector startPoint)
+        {
+            var remaining = new List<Shape>(cutouts);
+            var ordered = new List<Shape>();
+            var currentPoint = startPoint;
+
+            while (remaining.Count > 0)
+            {
+                var nearest = remaining[0];
+                var nearestPt = nearest.ClosestPointTo(currentPoint);
+                var nearestDist = nearestPt.DistanceTo(currentPoint);
+
+                for (var i = 1; i < remaining.Count; i++)
+                {
+                    var pt = remaining[i].ClosestPointTo(currentPoint);
+                    var dist = pt.DistanceTo(currentPoint);
+                    if (dist < nearestDist)
+                    {
+                        nearest = remaining[i];
+                        nearestPt = pt;
+                        nearestDist = dist;
+                    }
+                }
+
+                ordered.Add(nearest);
+                remaining.Remove(nearest);
+                currentPoint = nearestPt;
+            }
+
+            return ordered;
+        }
+
+        private ContourType DetectContourType(Shape cutout)
+        {
+            if (cutout.Entities.Count == 1 && cutout.Entities[0] is Circle)
+                return ContourType.ArcCircle;
+
+            return ContourType.Internal;
+        }
+
+        private double ComputeNormal(Vector point, Entity entity, ContourType contourType)
+        {
+            double normal;
+
+            if (entity is Line line)
+            {
+                // Perpendicular to line direction
+                var tangent = line.EndPoint.AngleFrom(line.StartPoint);
+                normal = tangent + Math.Angle.HalfPI;
+            }
+            else if (entity is Arc arc)
+            {
+                // Radial direction from center to point
+                normal = point.AngleFrom(arc.Center);
+            }
+            else if (entity is Circle circle)
+            {
+                normal = point.AngleFrom(circle.Center);
+            }
+            else
+            {
+                normal = 0;
+            }
+
+            // For internal contours, flip the normal (point into scrap)
+            if (contourType == ContourType.Internal || contourType == ContourType.ArcCircle)
+                normal += System.Math.PI;
+
+            return Math.Angle.NormalizeRad(normal);
+        }
+
+        private RotationType DetermineWinding(Shape shape)
+        {
+            // Use signed area: positive = CCW, negative = CW
+            var area = shape.Area();
+            return area >= 0 ? RotationType.CCW : RotationType.CW;
+        }
+
+        private LeadIn SelectLeadIn(ContourType contourType)
+        {
+            return contourType switch
+            {
+                ContourType.ArcCircle => Parameters.ArcCircleLeadIn ?? Parameters.InternalLeadIn,
+                ContourType.Internal => Parameters.InternalLeadIn,
+                _ => Parameters.ExternalLeadIn
+            };
+        }
+
+        private LeadOut SelectLeadOut(ContourType contourType)
+        {
+            return contourType switch
+            {
+                ContourType.ArcCircle => Parameters.ArcCircleLeadOut ?? Parameters.InternalLeadOut,
+                ContourType.Internal => Parameters.InternalLeadOut,
+                _ => Parameters.ExternalLeadOut
+            };
+        }
+
+        private List<ICode> ConvertShapeToMoves(Shape shape, Vector startPoint)
+        {
+            var moves = new List<ICode>();
+
+            foreach (var entity in shape.Entities)
+            {
+                if (entity is Line line)
+                {
+                    moves.Add(new LinearMove(line.EndPoint));
+                }
+                else if (entity is Arc arc)
+                {
+                    moves.Add(new ArcMove(arc.EndPoint(), arc.Center, arc.IsReversed ? RotationType.CW : RotationType.CCW));
+                }
+                else if (entity is Circle circle)
+                {
+                    moves.Add(new ArcMove(startPoint, circle.Center, circle.Rotation));
+                }
+                else
+                {
+                    throw new System.InvalidOperationException($"Unsupported entity type: {entity.Type}");
+                }
+            }
+
+            return moves;
+        }
+    }
+}

OpenNest.Core/CNC/CuttingStrategy/ContourType.cs

@@ -0,0 +1,9 @@
+namespace OpenNest.CNC.CuttingStrategy
+{
+    public enum ContourType
+    {
+        External,
+        Internal,
+        ArcCircle
+    }
+}

OpenNest.Core/CNC/CuttingStrategy/CuttingParameters.cs

@@ -0,0 +1,30 @@
+namespace OpenNest.CNC.CuttingStrategy
+{
+    public class CuttingParameters
+    {
+        public int Id { get; set; }
+
+        public string MachineName { get; set; }
+        public string MaterialName { get; set; }
+        public string Grade { get; set; }
+        public double Thickness { get; set; }
+
+        public double Kerf { get; set; }
+        public double PartSpacing { get; set; }
+
+        public LeadIn ExternalLeadIn { get; set; } = new NoLeadIn();
+        public LeadOut ExternalLeadOut { get; set; } = new NoLeadOut();
+
+        public LeadIn InternalLeadIn { get; set; } = new LineLeadIn { Length = 0.125, ApproachAngle = 90 };
+        public LeadOut InternalLeadOut { get; set; } = new NoLeadOut();
+
+        public LeadIn ArcCircleLeadIn { get; set; } = new NoLeadIn();
+        public LeadOut ArcCircleLeadOut { get; set; } = new NoLeadOut();
+
+        public Tab TabConfig { get; set; }
+        public bool TabsEnabled { get; set; }
+
+        public SequenceParameters Sequencing { get; set; } = new SequenceParameters();
+        public AssignmentParameters Assignment { get; set; } = new AssignmentParameters();
+    }
+}

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

@@ -0,0 +1,36 @@
+using System.Collections.Generic;
+using OpenNest.Geometry;
+
+namespace OpenNest.CNC.CuttingStrategy
+{
+    public class ArcLeadIn : LeadIn
+    {
+        public double Radius { get; set; }
+
+        public override List<ICode> Generate(Vector contourStartPoint, double contourNormalAngle,
+            RotationType winding = RotationType.CW)
+        {
+            var piercePoint = GetPiercePoint(contourStartPoint, contourNormalAngle);
+
+            var arcCenter = new Vector(
+                contourStartPoint.X + Radius * System.Math.Cos(contourNormalAngle),
+                contourStartPoint.Y + Radius * System.Math.Sin(contourNormalAngle));
+
+            return new List<ICode>
+            {
+                new RapidMove(piercePoint),
+                new ArcMove(contourStartPoint, arcCenter, winding)
+            };
+        }
+
+        public override Vector GetPiercePoint(Vector contourStartPoint, double contourNormalAngle)
+        {
+            var arcCenterX = contourStartPoint.X + Radius * System.Math.Cos(contourNormalAngle);
+            var arcCenterY = contourStartPoint.Y + Radius * System.Math.Sin(contourNormalAngle);
+
+            return new Vector(
+                arcCenterX + Radius * System.Math.Cos(contourNormalAngle),
+                arcCenterY + Radius * System.Math.Sin(contourNormalAngle));
+        }
+    }
+}

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

@@ -0,0 +1,49 @@
+using System.Collections.Generic;
+using OpenNest.Geometry;
+using OpenNest.Math;
+
+namespace OpenNest.CNC.CuttingStrategy
+{
+    public class CleanHoleLeadIn : LeadIn
+    {
+        public double LineLength { get; set; }
+        public double ArcRadius { get; set; }
+        public double Kerf { get; set; }
+
+        public override List<ICode> Generate(Vector contourStartPoint, double contourNormalAngle,
+            RotationType winding = RotationType.CW)
+        {
+            var piercePoint = GetPiercePoint(contourStartPoint, contourNormalAngle);
+
+            var arcCenterX = contourStartPoint.X + ArcRadius * System.Math.Cos(contourNormalAngle);
+            var arcCenterY = contourStartPoint.Y + ArcRadius * System.Math.Sin(contourNormalAngle);
+            var arcCenter = new Vector(arcCenterX, arcCenterY);
+
+            var lineAngle = contourNormalAngle + Angle.ToRadians(135.0);
+            var arcStart = new Vector(
+                arcCenterX + ArcRadius * System.Math.Cos(lineAngle),
+                arcCenterY + ArcRadius * System.Math.Sin(lineAngle));
+
+            return new List<ICode>
+            {
+                new RapidMove(piercePoint),
+                new LinearMove(arcStart),
+                new ArcMove(contourStartPoint, arcCenter, winding)
+            };
+        }
+
+        public override Vector GetPiercePoint(Vector contourStartPoint, double contourNormalAngle)
+        {
+            var arcCenterX = contourStartPoint.X + ArcRadius * System.Math.Cos(contourNormalAngle);
+            var arcCenterY = contourStartPoint.Y + ArcRadius * System.Math.Sin(contourNormalAngle);
+
+            var lineAngle = contourNormalAngle + Angle.ToRadians(135.0);
+            var arcStartX = arcCenterX + ArcRadius * System.Math.Cos(lineAngle);
+            var arcStartY = arcCenterY + ArcRadius * System.Math.Sin(lineAngle);
+
+            return new Vector(
+                arcStartX + LineLength * System.Math.Cos(lineAngle),
+                arcStartY + LineLength * System.Math.Sin(lineAngle));
+        }
+    }
+}

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

@@ -0,0 +1,13 @@
+using System.Collections.Generic;
+using OpenNest.Geometry;
+
+namespace OpenNest.CNC.CuttingStrategy
+{
+    public abstract class LeadIn
+    {
+        public abstract List<ICode> Generate(Vector contourStartPoint, double contourNormalAngle,
+            RotationType winding = RotationType.CW);
+
+        public abstract Vector GetPiercePoint(Vector contourStartPoint, double contourNormalAngle);
+    }
+}

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

@@ -0,0 +1,49 @@
+using System.Collections.Generic;
+using OpenNest.Geometry;
+using OpenNest.Math;
+
+namespace OpenNest.CNC.CuttingStrategy
+{
+    public class LineArcLeadIn : LeadIn
+    {
+        public double LineLength { get; set; }
+        public double ApproachAngle { get; set; } = 135.0;
+        public double ArcRadius { get; set; }
+
+        public override List<ICode> Generate(Vector contourStartPoint, double contourNormalAngle,
+            RotationType winding = RotationType.CW)
+        {
+            var piercePoint = GetPiercePoint(contourStartPoint, contourNormalAngle);
+
+            var arcCenterX = contourStartPoint.X + ArcRadius * System.Math.Cos(contourNormalAngle);
+            var arcCenterY = contourStartPoint.Y + ArcRadius * System.Math.Sin(contourNormalAngle);
+            var arcCenter = new Vector(arcCenterX, arcCenterY);
+
+            var lineAngle = contourNormalAngle + Angle.ToRadians(ApproachAngle);
+            var arcStart = new Vector(
+                arcCenterX + ArcRadius * System.Math.Cos(lineAngle),
+                arcCenterY + ArcRadius * System.Math.Sin(lineAngle));
+
+            return new List<ICode>
+            {
+                new RapidMove(piercePoint),
+                new LinearMove(arcStart),
+                new ArcMove(contourStartPoint, arcCenter, winding)
+            };
+        }
+
+        public override Vector GetPiercePoint(Vector contourStartPoint, double contourNormalAngle)
+        {
+            var arcCenterX = contourStartPoint.X + ArcRadius * System.Math.Cos(contourNormalAngle);
+            var arcCenterY = contourStartPoint.Y + ArcRadius * System.Math.Sin(contourNormalAngle);
+
+            var lineAngle = contourNormalAngle + Angle.ToRadians(ApproachAngle);
+            var arcStartX = arcCenterX + ArcRadius * System.Math.Cos(lineAngle);
+            var arcStartY = arcCenterY + ArcRadius * System.Math.Sin(lineAngle);
+
+            return new Vector(
+                arcStartX + LineLength * System.Math.Cos(lineAngle),
+                arcStartY + LineLength * System.Math.Sin(lineAngle));
+        }
+    }
+}

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

@@ -0,0 +1,32 @@
+using System.Collections.Generic;
+using OpenNest.Geometry;
+using OpenNest.Math;
+
+namespace OpenNest.CNC.CuttingStrategy
+{
+    public class LineLeadIn : LeadIn
+    {
+        public double Length { get; set; }
+        public double ApproachAngle { get; set; } = 90.0;
+
+        public override List<ICode> Generate(Vector contourStartPoint, double contourNormalAngle,
+            RotationType winding = RotationType.CW)
+        {
+            var piercePoint = GetPiercePoint(contourStartPoint, contourNormalAngle);
+
+            return new List<ICode>
+            {
+                new RapidMove(piercePoint),
+                new LinearMove(contourStartPoint)
+            };
+        }
+
+        public override Vector GetPiercePoint(Vector contourStartPoint, double contourNormalAngle)
+        {
+            var approachAngle = contourNormalAngle + 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

@@ -0,0 +1,44 @@
+using System.Collections.Generic;
+using OpenNest.Geometry;
+using OpenNest.Math;
+
+namespace OpenNest.CNC.CuttingStrategy
+{
+    public class LineLineLeadIn : LeadIn
+    {
+        public double Length1 { get; set; }
+        public double ApproachAngle1 { get; set; } = 90.0;
+        public double Length2 { get; set; }
+        public double ApproachAngle2 { get; set; } = 90.0;
+
+        public override List<ICode> Generate(Vector contourStartPoint, double contourNormalAngle,
+            RotationType winding = RotationType.CW)
+        {
+            var piercePoint = GetPiercePoint(contourStartPoint, contourNormalAngle);
+
+            var secondAngle = contourNormalAngle + Angle.ToRadians(ApproachAngle1);
+            var midPoint = new Vector(
+                contourStartPoint.X + Length2 * System.Math.Cos(secondAngle),
+                contourStartPoint.Y + Length2 * System.Math.Sin(secondAngle));
+
+            return new List<ICode>
+            {
+                new RapidMove(piercePoint),
+                new LinearMove(midPoint),
+                new LinearMove(contourStartPoint)
+            };
+        }
+
+        public override Vector GetPiercePoint(Vector contourStartPoint, double contourNormalAngle)
+        {
+            var secondAngle = contourNormalAngle + Angle.ToRadians(ApproachAngle1);
+            var midX = contourStartPoint.X + Length2 * System.Math.Cos(secondAngle);
+            var midY = contourStartPoint.Y + Length2 * System.Math.Sin(secondAngle);
+
+            var firstAngle = secondAngle + Angle.ToRadians(ApproachAngle2);
+            return new Vector(
+                midX + Length1 * System.Math.Cos(firstAngle),
+                midY + Length1 * System.Math.Sin(firstAngle));
+        }
+    }
+}

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

@@ -0,0 +1,22 @@
+using System.Collections.Generic;
+using OpenNest.Geometry;
+
+namespace OpenNest.CNC.CuttingStrategy
+{
+    public class NoLeadIn : LeadIn
+    {
+        public override List<ICode> Generate(Vector contourStartPoint, double contourNormalAngle,
+            RotationType winding = RotationType.CW)
+        {
+            return new List<ICode>
+            {
+                new RapidMove(contourStartPoint)
+            };
+        }
+
+        public override Vector GetPiercePoint(Vector contourStartPoint, double contourNormalAngle)
+        {
+            return contourStartPoint;
+        }
+    }
+}

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

@@ -0,0 +1,27 @@
+using System.Collections.Generic;
+using OpenNest.Geometry;
+
+namespace OpenNest.CNC.CuttingStrategy
+{
+    public class ArcLeadOut : LeadOut
+    {
+        public double Radius { get; set; }
+
+        public override List<ICode> Generate(Vector contourEndPoint, double contourNormalAngle,
+            RotationType winding = RotationType.CW)
+        {
+            var arcCenterX = contourEndPoint.X + Radius * System.Math.Cos(contourNormalAngle);
+            var arcCenterY = contourEndPoint.Y + Radius * System.Math.Sin(contourNormalAngle);
+            var arcCenter = new Vector(arcCenterX, arcCenterY);
+
+            var endPoint = new Vector(
+                arcCenterX + Radius * System.Math.Cos(contourNormalAngle + System.Math.PI / 2),
+                arcCenterY + Radius * System.Math.Sin(contourNormalAngle + System.Math.PI / 2));
+
+            return new List<ICode>
+            {
+                new ArcMove(endPoint, arcCenter, winding)
+            };
+        }
+    }
+}

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

@@ -0,0 +1,11 @@
+using System.Collections.Generic;
+using OpenNest.Geometry;
+
+namespace OpenNest.CNC.CuttingStrategy
+{
+    public abstract class LeadOut
+    {
+        public abstract List<ICode> Generate(Vector contourEndPoint, double contourNormalAngle,
+            RotationType winding = RotationType.CW);
+    }
+}

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

@@ -0,0 +1,26 @@
+using System.Collections.Generic;
+using OpenNest.Geometry;
+using OpenNest.Math;
+
+namespace OpenNest.CNC.CuttingStrategy
+{
+    public class LineLeadOut : LeadOut
+    {
+        public double Length { get; set; }
+        public double ApproachAngle { get; set; } = 90.0;
+
+        public override List<ICode> Generate(Vector contourEndPoint, double contourNormalAngle,
+            RotationType winding = RotationType.CW)
+        {
+            var overcutAngle = contourNormalAngle + 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)
+            };
+        }
+    }
+}

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

@@ -0,0 +1,16 @@
+using System.Collections.Generic;
+using OpenNest.Geometry;
+
+namespace OpenNest.CNC.CuttingStrategy
+{
+    public class MicrotabLeadOut : LeadOut
+    {
+        public double GapSize { get; set; } = 0.03;
+
+        public override List<ICode> Generate(Vector contourEndPoint, double contourNormalAngle,
+            RotationType winding = RotationType.CW)
+        {
+            return new List<ICode>();
+        }
+    }
+}

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

@@ -0,0 +1,14 @@
+using System.Collections.Generic;
+using OpenNest.Geometry;
+
+namespace OpenNest.CNC.CuttingStrategy
+{
+    public class NoLeadOut : LeadOut
+    {
+        public override List<ICode> Generate(Vector contourEndPoint, double contourNormalAngle,
+            RotationType winding = RotationType.CW)
+        {
+            return new List<ICode>();
+        }
+    }
+}

OpenNest.Core/CNC/CuttingStrategy/SequenceParameters.cs

@@ -0,0 +1,27 @@
+namespace OpenNest.CNC.CuttingStrategy
+{
+    // Values match PEP Technology's numbering scheme (value 6 intentionally skipped)
+    public enum SequenceMethod
+    {
+        RightSide = 1,
+        LeastCode = 2,
+        Advanced = 3,
+        BottomSide = 4,
+        EdgeStart = 5,
+        LeftSide = 7,
+        RightSideAlt = 8
+    }
+
+    public class SequenceParameters
+    {
+        public SequenceMethod Method { get; set; } = SequenceMethod.Advanced;
+        public double SmallCutoutWidth { get; set; } = 1.5;
+        public double SmallCutoutHeight { get; set; } = 1.5;
+        public double MediumCutoutWidth { get; set; } = 8.0;
+        public double MediumCutoutHeight { get; set; } = 8.0;
+        public double DistanceMediumSmall { get; set; }
+        public bool AlternateRowsColumns { get; set; } = true;
+        public bool AlternateCutoutsWithinRowColumn { get; set; } = true;
+        public double MinDistanceBetweenRowsColumns { get; set; } = 0.25;
+    }
+}

OpenNest.Core/CNC/CuttingStrategy/Tabs/BreakerTab.cs

@@ -0,0 +1,34 @@
+using System.Collections.Generic;
+using OpenNest.Geometry;
+
+namespace OpenNest.CNC.CuttingStrategy
+{
+    public class BreakerTab : Tab
+    {
+        public double BreakerDepth { get; set; }
+        public double BreakerLeadInLength { get; set; }
+        public double BreakerAngle { get; set; }
+
+        public override List<ICode> Generate(
+            Vector tabStartPoint, Vector tabEndPoint, double contourNormalAngle,
+            RotationType winding = RotationType.CW)
+        {
+            var codes = new List<ICode>();
+
+            if (TabLeadOut != null)
+                codes.AddRange(TabLeadOut.Generate(tabStartPoint, contourNormalAngle, winding));
+
+            var scoreAngle = contourNormalAngle + System.Math.PI;
+            var scoreEnd = new Vector(
+                tabStartPoint.X + BreakerDepth * System.Math.Cos(scoreAngle),
+                tabStartPoint.Y + BreakerDepth * System.Math.Sin(scoreAngle));
+            codes.Add(new LinearMove(scoreEnd));
+            codes.Add(new RapidMove(tabEndPoint));
+
+            if (TabLeadIn != null)
+                codes.AddRange(TabLeadIn.Generate(tabEndPoint, contourNormalAngle, winding));
+
+            return codes;
+        }
+    }
+}

OpenNest.Core/CNC/CuttingStrategy/Tabs/MachineTab.cs

@@ -0,0 +1,20 @@
+using System.Collections.Generic;
+using OpenNest.Geometry;
+
+namespace OpenNest.CNC.CuttingStrategy
+{
+    public class MachineTab : Tab
+    {
+        public int MachineTabId { get; set; }
+
+        public override List<ICode> Generate(
+            Vector tabStartPoint, Vector tabEndPoint, double contourNormalAngle,
+            RotationType winding = RotationType.CW)
+        {
+            return new List<ICode>
+            {
+                new RapidMove(tabEndPoint)
+            };
+        }
+    }
+}

OpenNest.Core/CNC/CuttingStrategy/Tabs/NormalTab.cs

@@ -0,0 +1,36 @@
+using System.Collections.Generic;
+using OpenNest.Geometry;
+
+namespace OpenNest.CNC.CuttingStrategy
+{
+    public class NormalTab : Tab
+    {
+        public double CutoutMinWidth { get; set; }
+        public double CutoutMinHeight { get; set; }
+        public double CutoutMaxWidth { get; set; }
+        public double CutoutMaxHeight { get; set; }
+
+        public override List<ICode> Generate(
+            Vector tabStartPoint, Vector tabEndPoint, double contourNormalAngle,
+            RotationType winding = RotationType.CW)
+        {
+            var codes = new List<ICode>();
+
+            if (TabLeadOut != null)
+                codes.AddRange(TabLeadOut.Generate(tabStartPoint, contourNormalAngle, winding));
+
+            codes.Add(new RapidMove(tabEndPoint));
+
+            if (TabLeadIn != null)
+                codes.AddRange(TabLeadIn.Generate(tabEndPoint, contourNormalAngle, winding));
+
+            return codes;
+        }
+
+        public bool AppliesToCutout(double cutoutWidth, double cutoutHeight)
+        {
+            return cutoutWidth >= CutoutMinWidth && cutoutWidth <= CutoutMaxWidth
+                && cutoutHeight >= CutoutMinHeight && cutoutHeight <= CutoutMaxHeight;
+        }
+    }
+}

OpenNest.Core/CNC/CuttingStrategy/Tabs/Tab.cs

@@ -0,0 +1,16 @@
+using System.Collections.Generic;
+using OpenNest.Geometry;
+
+namespace OpenNest.CNC.CuttingStrategy
+{
+    public abstract class Tab
+    {
+        public double Size { get; set; } = 0.03;
+        public LeadIn TabLeadIn { get; set; }
+        public LeadOut TabLeadOut { get; set; }
+
+        public abstract List<ICode> Generate(
+            Vector tabStartPoint, Vector tabEndPoint, double contourNormalAngle,
+            RotationType winding = RotationType.CW);
+    }
+}

OpenNest.Core/Geometry/Arc.cs

@@ -155,6 +155,28 @@ namespace OpenNest.Geometry
                 Center.Y + Radius * System.Math.Sin(EndAngle));
         }
 
+        /// <summary>
+        /// Splits the arc at the given point, returning two sub-arcs.
+        /// Either half may be null if the split point coincides with an endpoint.
+        /// </summary>
+        /// <param name="point">The point at which to split the arc.</param>
+        /// <returns>A tuple of (first, second) sub-arcs.</returns>
+        public (Arc first, Arc second) SplitAt(Vector point)
+        {
+            if (point.DistanceTo(StartPoint()) < Tolerance.Epsilon)
+                return (null, new Arc(Center, Radius, StartAngle, EndAngle, IsReversed));
+
+            if (point.DistanceTo(EndPoint()) < Tolerance.Epsilon)
+                return (new Arc(Center, Radius, StartAngle, EndAngle, IsReversed), null);
+
+            var splitAngle = Angle.NormalizeRad(Center.AngleTo(point));
+
+            var firstArc = new Arc(Center, Radius, StartAngle, splitAngle, IsReversed);
+            var secondArc = new Arc(Center, Radius, splitAngle, EndAngle, IsReversed);
+
+            return (firstArc, secondArc);
+        }
+
         /// <summary>
         /// Returns true if the given arc has the same center point and radius as this.
         /// </summary>
@@ -388,7 +410,7 @@ namespace OpenNest.Geometry
             boundingBox.X = minX;
             boundingBox.Y = minY;
             boundingBox.Width = maxX - minX;
-            boundingBox.Height = maxY - minY;
+            boundingBox.Length = maxY - minY;
         }
 
         public override Entity OffsetEntity(double distance, OffsetSide side)

OpenNest.Core/Geometry/BoundingBox.cs

@@ -13,7 +13,7 @@ namespace OpenNest.Geometry
             double minX = boxes[0].X;
             double minY = boxes[0].Y;
             double maxX = boxes[0].X + boxes[0].Width;
-            double maxY = boxes[0].Y + boxes[0].Height;
+            double maxY = boxes[0].Y + boxes[0].Length;
 
             foreach (var box in boxes)
             {

OpenNest.Core/Geometry/Box.cs

@@ -15,14 +15,14 @@ namespace OpenNest.Geometry
         {
             Location = new Vector(x, y);
             Width = w;
-            Height = h;
+            Length = h;
         }
 
         public Vector Location;
 
         public Vector Center
         {
-            get { return new Vector(X + Width * 0.5, Y + Height * 0.5); }
+            get { return new Vector(X + Width * 0.5, Y + Length * 0.5); }
         }
 
         public Size Size;
@@ -45,10 +45,10 @@ namespace OpenNest.Geometry
             set { Size.Width = value; }
         }
 
-        public double Height
+        public double Length
         {
-            get { return Size.Height; }
+            get { return Size.Length; }
-            set { Size.Height = value; }
+            set { Size.Length = value; }
         }
 
         public void MoveTo(double x, double y)
@@ -86,7 +86,7 @@ namespace OpenNest.Geometry
 
         public double Top
         {
-            get { return Y + Height; }
+            get { return Y + Length; }
         }
 
         public double Bottom
@@ -96,12 +96,12 @@ namespace OpenNest.Geometry
 
         public double Area()
         {
-            return Width * Height;
+            return Width * Length;
         }
 
         public double Perimeter()
         {
-            return Width * 2 + Height * 2;
+            return Width * 2 + Length * 2;
         }
 
         public bool Intersects(Box box)
@@ -197,12 +197,12 @@ namespace OpenNest.Geometry
 
         public Box Offset(double d)
         {
-            return new Box(X - d, Y - d, Width + d * 2, Height + d * 2);
+            return new Box(X - d, Y - d, Width + d * 2, Length + d * 2);
         }
 
         public override string ToString()
         {
-            return string.Format("[Box: X={0}, Y={1}, Width={2}, Height={3}]", X, Y, Width, Height);
+            return string.Format("[Box: X={0}, Y={1}, Width={2}, Length={3}]", X, Y, Width, Length);
         }
     }
 }

OpenNest.Core/Geometry/BoxSplitter.cs

@@ -23,7 +23,7 @@
             var x = large.Left;
             var y = large.Bottom;
             var w = small.Left - x;
-            var h = large.Height;
+            var h = large.Length;
 
             return new Box(x, y, w, h);
         }
@@ -49,7 +49,7 @@
             var x = small.Right;
             var y = large.Bottom;
             var w = large.Right - x;
-            var h = large.Height;
+            var h = large.Length;
 
             return new Box(x, y, w, h);
         }

OpenNest.Core/Geometry/Circle.cs

@@ -263,7 +263,7 @@ namespace OpenNest.Geometry
             boundingBox.X = Center.X - Radius;
             boundingBox.Y = Center.Y - Radius;
             boundingBox.Width = Diameter;
-            boundingBox.Height = Diameter;
+            boundingBox.Length = Diameter;
         }
 
         public override Entity OffsetEntity(double distance, OffsetSide side)

OpenNest.Core/Geometry/Line.cs

@@ -381,12 +381,12 @@ namespace OpenNest.Geometry
             if (StartPoint.Y < EndPoint.Y)
             {
                 boundingBox.Y = StartPoint.Y;
-                boundingBox.Height = EndPoint.Y - StartPoint.Y;
+                boundingBox.Length = EndPoint.Y - StartPoint.Y;
             }
             else
             {
                 boundingBox.Y = EndPoint.Y;
-                boundingBox.Height = StartPoint.Y - EndPoint.Y;
+                boundingBox.Length = StartPoint.Y - EndPoint.Y;
             }
         }
 
@@ -414,6 +414,25 @@ namespace OpenNest.Geometry
             return OffsetEntity(distance, side);
         }
 
+        /// <summary>
+        /// Splits the line at the given point, returning two sub-lines.
+        /// Either half may be null if the split point coincides with an endpoint.
+        /// </summary>
+        /// <param name="point">The point at which to split the line.</param>
+        /// <returns>A tuple of (first, second) sub-lines.</returns>
+        public (Line first, Line second) SplitAt(Vector point)
+        {
+            var first = point.DistanceTo(StartPoint) < Tolerance.Epsilon
+                ? null
+                : new Line(StartPoint, point);
+
+            var second = point.DistanceTo(EndPoint) < Tolerance.Epsilon
+                ? null
+                : new Line(point, EndPoint);
+
+            return (first, second);
+        }
+
         /// <summary>
         /// Gets the closest point on the line to the given point.
         /// </summary>

OpenNest.Core/Geometry/Polygon.cs

@@ -312,7 +312,7 @@ namespace OpenNest.Geometry
             boundingBox.X = minX;
             boundingBox.Y = minY;
             boundingBox.Width = maxX - minX;
-            boundingBox.Height = maxY - minY;
+            boundingBox.Length = maxY - minY;
         }
 
         public override Entity OffsetEntity(double distance, OffsetSide side)

OpenNest.Core/Geometry/Shape.cs

@@ -201,6 +201,68 @@ namespace OpenNest.Geometry
             return closestPt;
         }
 
+        /// <summary>
+        /// Returns a new shape with entities reordered so that the given point on
+        /// the given entity becomes the new start point of the contour.
+        /// </summary>
+        /// <param name="point">The point on the entity to reindex at.</param>
+        /// <param name="entity">The entity containing the point.</param>
+        /// <returns>A new reindexed shape.</returns>
+        public Shape ReindexAt(Vector point, Entity entity)
+        {
+            // Circle case: return a new shape with just the circle
+            if (entity is Circle)
+            {
+                var result = new Shape();
+                result.Entities.Add(entity);
+                return result;
+            }
+
+            var i = Entities.IndexOf(entity);
+            if (i < 0)
+                throw new ArgumentException("Entity not found in shape", nameof(entity));
+
+            // Split the entity at the point
+            Entity firstHalf = null;
+            Entity secondHalf = null;
+
+            if (entity is Line line)
+            {
+                var (f, s) = line.SplitAt(point);
+                firstHalf = f;
+                secondHalf = s;
+            }
+            else if (entity is Arc arc)
+            {
+                var (f, s) = arc.SplitAt(point);
+                firstHalf = f;
+                secondHalf = s;
+            }
+
+            // Build reindexed entity list
+            var entities = new List<Entity>();
+
+            // secondHalf of split entity (if not null)
+            if (secondHalf != null)
+                entities.Add(secondHalf);
+
+            // Entities after the split index (wrapping)
+            for (var j = i + 1; j < Entities.Count; j++)
+                entities.Add(Entities[j]);
+
+            // Entities before the split index (wrapping)
+            for (var j = 0; j < i; j++)
+                entities.Add(Entities[j]);
+
+            // firstHalf of split entity (if not null)
+            if (firstHalf != null)
+                entities.Add(firstHalf);
+
+            var reindexed = new Shape();
+            reindexed.Entities.AddRange(entities);
+            return reindexed;
+        }
+
         /// <summary>
         /// Converts the shape to a polygon.
         /// </summary>
@@ -399,7 +461,7 @@ namespace OpenNest.Geometry
         public override Entity OffsetEntity(double distance, OffsetSide side)
         {
             var offsetShape = new Shape();
-            var definedShape = new DefinedShape(this);
+            var definedShape = new ShapeProfile(this);
 
             Entity lastEntity = null;
             Entity lastOffsetEntity = null;

OpenNest.Core/Geometry/ShapeProfile.cs

@@ -2,14 +2,14 @@
 
 namespace OpenNest.Geometry
 {
-    public class DefinedShape
+    public class ShapeProfile
     {
-        public DefinedShape(Shape shape)
+        public ShapeProfile(Shape shape)
         {
             Update(shape.Entities);
         }
 
-        public DefinedShape(List<Entity> entities)
+        public ShapeProfile(List<Entity> entities)
         {
             Update(entities);
         }

OpenNest.Core/Geometry/Size.cs

@@ -1,16 +1,16 @@
-using System;
+using System;
 
 namespace OpenNest.Geometry
 {
     public struct Size
     {
-        public Size(double width, double height)
+        public Size(double width, double length)
         {
-            Height = height;
+            Length = length;
             Width = width;
         }
 
-        public double Height;
+        public double Length;
 
         public double Width;
 
@@ -21,10 +21,10 @@ namespace OpenNest.Geometry
             if (a.Length > 2)
                 throw new FormatException("Invalid size format.");
 
-            var height = double.Parse(a[0]);
+            var length = double.Parse(a[0]);
             var width = double.Parse(a[1]);
 
-            return new Size(width, height);
+            return new Size(width, length);
         }
 
         public static bool TryParse(string s, out Size size)
@@ -44,12 +44,12 @@ namespace OpenNest.Geometry
 
         public override string ToString()
         {
-            return string.Format("{0} x {1}", Height, Width);
+            return string.Format("{0} x {1}", Length, Width);
         }
 
         public string ToString(int decimalPlaces)
         {
-            return string.Format("{0} x {1}", System.Math.Round(Height, decimalPlaces), System.Math.Round(Width, decimalPlaces));
+            return string.Format("{0} x {1}", System.Math.Round(Length, decimalPlaces), System.Math.Round(Width, decimalPlaces));
         }
     }
 }

OpenNest.Core/Part.cs

@@ -220,7 +220,7 @@ namespace OpenNest
             var part = new Part(BaseDrawing, clonedProgram,
                 location + offset,
                 new Box(BoundingBox.X + offset.X, BoundingBox.Y + offset.Y,
-                    BoundingBox.Width, BoundingBox.Height));
+                    BoundingBox.Width, BoundingBox.Length));
 
             return part;
         }

OpenNest.Core/Plate.cs

@@ -117,7 +117,7 @@ namespace OpenNest
         {
             const double oneAndHalfPI = System.Math.PI * 1.5;
 
-            Size = new Size(Size.Height, Size.Width);
+            Size = new Size(Size.Length, Size.Width);
 
             if (rotationDirection == RotationType.CW)
             {
@@ -128,7 +128,7 @@ namespace OpenNest
                     switch (Quadrant)
                     {
                         case 1:
-                            Offset(0, Size.Height);
+                            Offset(0, Size.Length);
                             break;
 
                         case 2:
@@ -136,7 +136,7 @@ namespace OpenNest
                             break;
 
                         case 3:
-                            Offset(0, -Size.Height);
+                            Offset(0, -Size.Length);
                             break;
 
                         case 4:
@@ -165,7 +165,7 @@ namespace OpenNest
                             break;
 
                         case 2:
-                            Offset(0, Size.Height);
+                            Offset(0, Size.Length);
                             break;
 
                         case 3:
@@ -173,7 +173,7 @@ namespace OpenNest
                             break;
 
                         case 4:
-                            Offset(0, -Size.Height);
+                            Offset(0, -Size.Length);
                             break;
 
                         default:
@@ -200,19 +200,19 @@ namespace OpenNest
                 switch (Quadrant)
                 {
                     case 1:
-                        centerpt = new Vector(Size.Width * 0.5, Size.Height * 0.5);
+                        centerpt = new Vector(Size.Width * 0.5, Size.Length * 0.5);
                         break;
 
                     case 2:
-                        centerpt = new Vector(-Size.Width * 0.5, Size.Height * 0.5);
+                        centerpt = new Vector(-Size.Width * 0.5, Size.Length * 0.5);
                         break;
 
                     case 3:
-                        centerpt = new Vector(-Size.Width * 0.5, -Size.Height * 0.5);
+                        centerpt = new Vector(-Size.Width * 0.5, -Size.Length * 0.5);
                         break;
 
                     case 4:
-                        centerpt = new Vector(Size.Width * 0.5, -Size.Height * 0.5);
+                        centerpt = new Vector(Size.Width * 0.5, -Size.Length * 0.5);
                         break;
 
                     default:
@@ -308,12 +308,12 @@ namespace OpenNest
 
                 case 3:
                     plateBox.X = (float)-Size.Width;
-                    plateBox.Y = (float)-Size.Height;
+                    plateBox.Y = (float)-Size.Length;
                     break;
 
                 case 4:
                     plateBox.X = 0;
-                    plateBox.Y = (float)-Size.Height;
+                    plateBox.Y = (float)-Size.Length;
                     break;
 
                 default:
@@ -321,7 +321,7 @@ namespace OpenNest
             }
 
             plateBox.Width = Size.Width;
-            plateBox.Height = Size.Height;
+            plateBox.Length = Size.Length;
 
             if (!includeParts)
                 return plateBox;
@@ -341,7 +341,7 @@ namespace OpenNest
                 ? partsBox.Right - boundingBox.X
                 : plateBox.Right - boundingBox.X;
 
-            boundingBox.Height = partsBox.Top > plateBox.Top
+            boundingBox.Length = partsBox.Top > plateBox.Top
                 ? partsBox.Top - boundingBox.Y
                 : plateBox.Top - boundingBox.Y;
 
@@ -359,7 +359,7 @@ namespace OpenNest
             box.X += EdgeSpacing.Left;
             box.Y += EdgeSpacing.Bottom;
             box.Width -= EdgeSpacing.Left + EdgeSpacing.Right;
-            box.Height -= EdgeSpacing.Top + EdgeSpacing.Bottom;
+            box.Length -= EdgeSpacing.Top + EdgeSpacing.Bottom;
 
             return box;
         }
@@ -383,28 +383,28 @@ namespace OpenNest
             var bounds = Parts.GetBoundingBox();
 
             double width;
-            double height;
+            double length;
 
             switch (Quadrant)
             {
                 case 1:
                     width = System.Math.Abs(bounds.Right) + EdgeSpacing.Right;
-                    height = System.Math.Abs(bounds.Top) + EdgeSpacing.Top;
+                    length = System.Math.Abs(bounds.Top) + EdgeSpacing.Top;
                     break;
 
                 case 2:
                     width = System.Math.Abs(bounds.Left) + EdgeSpacing.Left;
-                    height = System.Math.Abs(bounds.Top) + EdgeSpacing.Top;
+                    length = System.Math.Abs(bounds.Top) + EdgeSpacing.Top;
                     break;
 
                 case 3:
                     width = System.Math.Abs(bounds.Left) + EdgeSpacing.Left;
-                    height = System.Math.Abs(bounds.Bottom) + EdgeSpacing.Bottom;
+                    length = System.Math.Abs(bounds.Bottom) + EdgeSpacing.Bottom;
                     break;
 
                 case 4:
                     width = System.Math.Abs(bounds.Right) + EdgeSpacing.Right;
-                    height = System.Math.Abs(bounds.Bottom) + EdgeSpacing.Bottom;
+                    length = System.Math.Abs(bounds.Bottom) + EdgeSpacing.Bottom;
                     break;
 
                 default:
@@ -413,7 +413,7 @@ namespace OpenNest
 
             Size = new Size(
                 Helper.RoundUpToNearest(width, roundingFactor),
-                Helper.RoundUpToNearest(height, roundingFactor));
+                Helper.RoundUpToNearest(length, roundingFactor));
         }
 
         /// <summary>
@@ -422,7 +422,7 @@ namespace OpenNest
         /// <returns></returns>
         public double Area()
         {
-            return Size.Width * Size.Height;
+            return Size.Width * Size.Length;
         }
 
         /// <summary>
@@ -503,7 +503,7 @@ namespace OpenNest
 
             if (maxRight < work.Right)
             {
-                var strip = new Box(maxRight, work.Bottom, work.Right - maxRight, work.Height);
+                var strip = new Box(maxRight, work.Bottom, work.Right - maxRight, work.Length);
                 if (strip.Area() > 1.0)
                     results.Add(strip);
             }
@@ -548,7 +548,7 @@ namespace OpenNest
 
             if (minLeft > work.Left)
             {
-                var strip = new Box(work.Left, work.Bottom, minLeft - work.Left, work.Height);
+                var strip = new Box(work.Left, work.Bottom, minLeft - work.Left, work.Length);
                 if (strip.Area() > 1.0)
                     results.Add(strip);
             }

OpenNest.Engine/BestFit/PairEvaluator.cs

@@ -57,7 +57,7 @@ namespace OpenNest.Engine.BestFit
                 var combinedBox = ((IEnumerable<IBoundable>)new IBoundable[] { part1, part2 }).GetBoundingBox();
                 bestArea = combinedBox.Area();
                 bestWidth = combinedBox.Width;
-                bestHeight = combinedBox.Height;
+                bestHeight = combinedBox.Length;
                 bestRotation = 0;
             }
 

OpenNest.Engine/BestFit/RotationSlideStrategy.cs

@@ -64,15 +64,15 @@ namespace OpenNest.Engine.BestFit
 
             if (isHorizontalPush)
             {
-                perpMin = -(bbox2.Height + spacing);
+                perpMin = -(bbox2.Length + spacing);
-                perpMax = bbox1.Height + bbox2.Height + spacing;
+                perpMax = bbox1.Length + bbox2.Length + spacing;
                 pushStartOffset = bbox1.Width + bbox2.Width + spacing * 2;
             }
             else
             {
                 perpMin = -(bbox2.Width + spacing);
                 perpMax = bbox1.Width + bbox2.Width + spacing;
-                pushStartOffset = bbox1.Height + bbox2.Height + spacing * 2;
+                pushStartOffset = bbox1.Length + bbox2.Length + spacing * 2;
             }
 
             // Pre-compute part1's offset lines (half-spacing outward)

OpenNest.Engine/BestFit/Tiling/TileEvaluator.cs

@@ -9,7 +9,7 @@ namespace OpenNest.Engine.BestFit.Tiling
         public TileResult Evaluate(BestFitResult bestFit, Plate plate)
         {
             var plateWidth = plate.Size.Width - plate.EdgeSpacing.Left - plate.EdgeSpacing.Right;
-            var plateHeight = plate.Size.Height - plate.EdgeSpacing.Top - plate.EdgeSpacing.Bottom;
+            var plateHeight = plate.Size.Length - plate.EdgeSpacing.Top - plate.EdgeSpacing.Bottom;
 
             var result1 = TryTile(bestFit, plateWidth, plateHeight, false);
             var result2 = TryTile(bestFit, plateWidth, plateHeight, true);

OpenNest.Engine/CirclePacking/FillEndEven.cs

@@ -17,10 +17,10 @@ namespace OpenNest.CirclePacking
                 Bin.Right - item.BoundingBox.Right + Tolerance.Epsilon,
                 Bin.Top - item.BoundingBox.Top + Tolerance.Epsilon);
 
-            var rows = System.Math.Floor((Bin.Height + Tolerance.Epsilon) / (item.Diameter));
+            var rows = System.Math.Floor((Bin.Length + Tolerance.Epsilon) / (item.Diameter));
 
             var diameter = item.Diameter;
-            var remaining = Bin.Height - diameter * rows;
+            var remaining = Bin.Length - diameter * rows;
             var radius = diameter * 0.5;
 
             if (remaining < radius)
@@ -47,7 +47,7 @@ namespace OpenNest.CirclePacking
             }
             else
             {
-                var yoffset = (Bin.Height - diameter) / (2 * rows - 1);
+                var yoffset = (Bin.Length - diameter) / (2 * rows - 1);
                 var xoffset = Trigonometry.Base(yoffset, diameter);
 
                 var yodd = Bin.Y + yoffset;

OpenNest.Engine/CirclePacking/FillEndOdd.cs

@@ -71,12 +71,12 @@ namespace OpenNest.CirclePacking
                 Bin.Right - item.BoundingBox.Right + Tolerance.Epsilon,
                 Bin.Top - item.BoundingBox.Top + Tolerance.Epsilon);
 
-            var count = System.Math.Floor((bin.Height + Tolerance.Epsilon) / item.Diameter);
+            var count = System.Math.Floor((bin.Length + Tolerance.Epsilon) / item.Diameter);
 
             if (count == 0)
                 return bin;
 
-            var yoffset = (bin.Height - item.Diameter) / (count - 1);
+            var yoffset = (bin.Length - item.Diameter) / (count - 1);
             var xoffset = Trigonometry.Base(yoffset * 0.5, item.Diameter);
 
             int column = 0;

OpenNest.Engine/FillLinear.cs

@@ -9,7 +9,7 @@ namespace OpenNest
         public FillLinear(Box workArea, double partSpacing)
         {
             PartSpacing = partSpacing;
-            WorkArea = new Box(workArea.X, workArea.Y, workArea.Width, workArea.Height);
+            WorkArea = new Box(workArea.X, workArea.Y, workArea.Width, workArea.Length);
         }
 
         public Box WorkArea { get; }
@@ -34,7 +34,7 @@ namespace OpenNest
 
         private static double GetDimension(Box box, NestDirection direction)
         {
-            return direction == NestDirection.Horizontal ? box.Width : box.Height;
+            return direction == NestDirection.Horizontal ? box.Width : box.Length;
         }
 
         private static double GetStart(Box box, NestDirection direction)
@@ -321,7 +321,7 @@ namespace OpenNest
             template.Offset(WorkArea.Location - template.BoundingBox.Location);
 
             if (template.BoundingBox.Width > WorkArea.Width + Tolerance.Epsilon ||
-                template.BoundingBox.Height > WorkArea.Height + Tolerance.Epsilon)
+                template.BoundingBox.Length > WorkArea.Length + Tolerance.Epsilon)
                 return pattern;
 
             pattern.Parts.Add(template);
@@ -472,7 +472,7 @@ namespace OpenNest
                 if (width <= Tolerance.Epsilon)
                     return new List<Part>();
 
-                remainingStrip = new Box(left, WorkArea.Y, width, WorkArea.Height);
+                remainingStrip = new Box(left, WorkArea.Y, width, WorkArea.Length);
             }
 
             // Build rotation set: always try cardinal orientations (0° and 90°),
@@ -601,7 +601,7 @@ namespace OpenNest
             var basePattern = pattern.Clone(offset);
 
             if (basePattern.BoundingBox.Width > WorkArea.Width + Tolerance.Epsilon ||
-                basePattern.BoundingBox.Height > WorkArea.Height + Tolerance.Epsilon)
+                basePattern.BoundingBox.Length > WorkArea.Length + Tolerance.Epsilon)
                 return new List<Part>();
 
             return FillRecursive(basePattern, primaryAxis, depth: 0);

OpenNest.Engine/FillScore.cs

@@ -80,7 +80,7 @@ namespace OpenNest
             if (maxRight < workArea.Right)
             {
                 var width = workArea.Right - maxRight;
-                var height = workArea.Height;
+                var height = workArea.Length;
 
                 if (System.Math.Min(width, height) >= MinRemnantDimension)
                     largest = System.Math.Max(largest, width * height);

OpenNest.Engine/NestEngine.cs

@@ -70,8 +70,8 @@ namespace OpenNest
 
             testPart.UpdateBounds();
 
-            var partLongestSide = System.Math.Max(testPart.BoundingBox.Width, testPart.BoundingBox.Height);
+            var partLongestSide = System.Math.Max(testPart.BoundingBox.Width, testPart.BoundingBox.Length);
-            var workAreaShortSide = System.Math.Min(workArea.Width, workArea.Height);
+            var workAreaShortSide = System.Math.Min(workArea.Width, workArea.Length);
 
             if (workAreaShortSide < partLongestSide)
             {
@@ -113,7 +113,7 @@ namespace OpenNest
             }
 
             var bestLinearScore = best != null ? FillScore.Compute(best, workArea) : default;
-            Debug.WriteLine($"[FindBestFill] Linear: {bestLinearScore.Count} parts, density={bestLinearScore.Density:P1} | WorkArea: {workArea.Width:F1}x{workArea.Height:F1} | Angles: {angles.Count}");
+            Debug.WriteLine($"[FindBestFill] Linear: {bestLinearScore.Count} parts, density={bestLinearScore.Density:P1} | WorkArea: {workArea.Width:F1}x{workArea.Length:F1} | Angles: {angles.Count}");
 
             // Try rectangle best-fit (mixes orientations to fill remnant strips).
             var rectResult = FillRectangleBestFit(item, workArea);
@@ -143,7 +143,7 @@ namespace OpenNest
             var angles = RotationAnalysis.FindHullEdgeAngles(groupParts);
             var best = FillPattern(engine, groupParts, angles, workArea);
 
-            Debug.WriteLine($"[Fill(groupParts,Box)] Linear: {best?.Count ?? 0} parts | WorkArea: {workArea.Width:F1}x{workArea.Height:F1}");
+            Debug.WriteLine($"[Fill(groupParts,Box)] Linear: {best?.Count ?? 0} parts | WorkArea: {workArea.Width:F1}x{workArea.Length:F1}");
 
             if (groupParts.Count == 1)
             {
@@ -213,7 +213,7 @@ namespace OpenNest
         private List<Part> FillWithPairs(NestItem item, Box workArea)
         {
             var bestFits = BestFitCache.GetOrCompute(
-                item.Drawing, Plate.Size.Width, Plate.Size.Height,
+                item.Drawing, Plate.Size.Width, Plate.Size.Length,
                 Plate.PartSpacing);
 
             var candidates = SelectPairCandidates(bestFits, workArea);
@@ -260,8 +260,8 @@ namespace OpenNest
             var kept = bestFits.Where(r => r.Keep).ToList();
             var top = kept.Take(50).ToList();
 
-            var workShortSide = System.Math.Min(workArea.Width, workArea.Height);
+            var workShortSide = System.Math.Min(workArea.Width, workArea.Length);
-            var plateShortSide = System.Math.Min(Plate.Size.Width, Plate.Size.Height);
+            var plateShortSide = System.Math.Min(Plate.Size.Width, Plate.Size.Length);
 
             // When the work area is significantly narrower than the plate,
             // include all pairs that fit the narrow dimension.
@@ -356,7 +356,7 @@ namespace OpenNest
 
             var refDim = horizontal
                 ? sorted.Max(p => p.BoundingBox.Width)
-                : sorted.Max(p => p.BoundingBox.Height);
+                : sorted.Max(p => p.BoundingBox.Length);
             var gapThreshold = refDim * 0.5;
 
             var clusters = new List<List<Part>>();
@@ -425,7 +425,7 @@ namespace OpenNest
                 if (stripWidth <= 0)
                     return null;
 
-                stripBox = new Box(stripLeft, workArea.Y, stripWidth, workArea.Height);
+                stripBox = new Box(stripLeft, workArea.Y, stripWidth, workArea.Length);
             }
             else
             {
@@ -438,7 +438,7 @@ namespace OpenNest
                 stripBox = new Box(workArea.X, stripBottom, workArea.Width, stripHeight);
             }
 
-            Debug.WriteLine($"[TryStripRefill] Strip: {stripBox.Width:F1}x{stripBox.Height:F1} at ({stripBox.X:F1},{stripBox.Y:F1})");
+            Debug.WriteLine($"[TryStripRefill] Strip: {stripBox.Width:F1}x{stripBox.Length:F1} at ({stripBox.X:F1},{stripBox.Y:F1})");
 
             var stripParts = FindBestFill(item, stripBox);
 

OpenNest.Engine/RectanglePacking/BinConverter.cs

@@ -15,7 +15,7 @@ namespace OpenNest.RectanglePacking
             };
 
             bin.Width += partSpacing;
-            bin.Height += partSpacing;
+            bin.Length += partSpacing;
 
             return bin;
         }
@@ -25,7 +25,7 @@ namespace OpenNest.RectanglePacking
             var box = item.Drawing.Program.BoundingBox();
 
             box.Width += partSpacing;
-            box.Height += partSpacing;
+            box.Length += partSpacing;
 
             return new Item
             {

OpenNest.Engine/RectanglePacking/FillBestFit.cs

@@ -44,11 +44,11 @@ namespace OpenNest.RectanglePacking
             int normalColumns = 0;
             int rotateColumns = 0;
 
-            if (!BestCombination.FindFrom2(item.Width, item.Height, bin.Width, out normalColumns, out rotateColumns))
+            if (!BestCombination.FindFrom2(item.Width, item.Length, bin.Width, out normalColumns, out rotateColumns))
                 return bin;
 
-            var normalRows = (int)System.Math.Floor((bin.Height + Tolerance.Epsilon) / item.Height);
+            var normalRows = (int)System.Math.Floor((bin.Length + Tolerance.Epsilon) / item.Length);
-            var rotateRows = (int)System.Math.Floor((bin.Height + Tolerance.Epsilon) / item.Width);
+            var rotateRows = (int)System.Math.Floor((bin.Length + Tolerance.Epsilon) / item.Width);
 
             item.Location = bin.Location;
 
@@ -69,17 +69,17 @@ namespace OpenNest.RectanglePacking
             int normalRows = 0;
             int rotateRows = 0;
 
-            if (!BestCombination.FindFrom2(item.Height, item.Width, Bin.Height, out normalRows, out rotateRows))
+            if (!BestCombination.FindFrom2(item.Length, item.Width, Bin.Length, out normalRows, out rotateRows))
                 return bin;
 
             var normalColumns = (int)System.Math.Floor((Bin.Width + Tolerance.Epsilon) / item.Width);
-            var rotateColumns = (int)System.Math.Floor((Bin.Width + Tolerance.Epsilon) / item.Height);
+            var rotateColumns = (int)System.Math.Floor((Bin.Width + Tolerance.Epsilon) / item.Length);
 
             item.Location = bin.Location;
 
             bin.Items.AddRange(FillGrid(item, normalRows, normalColumns, int.MaxValue));
 
-            item.Location.Y += item.Height * normalRows;
+            item.Location.Y += item.Length * normalRows;
             item.Rotate();
 
             bin.Items.AddRange(FillGrid(item, rotateRows, rotateColumns, int.MaxValue));

OpenNest.Engine/RectanglePacking/FillEngine.cs

@@ -28,7 +28,7 @@ namespace OpenNest.RectanglePacking
                 for (var j = 0; j < innerCount; j++)
                 {
                     var x = (columnMajor ? i : j) * item.Width + item.X;
-                    var y = (columnMajor ? j : i) * item.Height + item.Y;
+                    var y = (columnMajor ? j : i) * item.Length + item.Y;
 
                     var clone = item.Clone() as Item;
                     clone.Location = new Vector(x, y);

OpenNest.Engine/RectanglePacking/FillNoRotation.cs

@@ -15,7 +15,7 @@ namespace OpenNest.RectanglePacking
 
         public override void Fill(Item item)
         {
-            var ycount = (int)System.Math.Floor((Bin.Height + Tolerance.Epsilon) / item.Height);
+            var ycount = (int)System.Math.Floor((Bin.Length + Tolerance.Epsilon) / item.Length);
             var xcount = (int)System.Math.Floor((Bin.Width + Tolerance.Epsilon) / item.Width);
 
             for (int i = 0; i < xcount; i++)
@@ -24,7 +24,7 @@ namespace OpenNest.RectanglePacking
 
                 for (int j = 0; j < ycount; j++)
                 {
-                    var y = item.Height * j + Bin.Y;
+                    var y = item.Length * j + Bin.Y;
 
                     var addedItem = item.Clone() as Item;
                     addedItem.Location = new Vector(x, y);
@@ -36,7 +36,7 @@ namespace OpenNest.RectanglePacking
 
         public override void Fill(Item item, int maxCount)
         {
-            var ycount = (int)System.Math.Floor((Bin.Height + Tolerance.Epsilon) / item.Height);
+            var ycount = (int)System.Math.Floor((Bin.Length + Tolerance.Epsilon) / item.Length);
             var xcount = (int)System.Math.Floor((Bin.Width + Tolerance.Epsilon) / item.Width);
             var count = ycount * xcount;
 
@@ -60,7 +60,7 @@ namespace OpenNest.RectanglePacking
                 columns = (int)System.Math.Ceiling((double)maxCount / rows);
             }
 
-            Bin.Items.AddRange(FillGrid(item, rows, columns, maxCount, columnMajor: item.Width > item.Height));
+            Bin.Items.AddRange(FillGrid(item, rows, columns, maxCount, columnMajor: item.Width > item.Length));
         }
     }
 }

OpenNest.Engine/RectanglePacking/Item.cs

@@ -12,7 +12,7 @@ namespace OpenNest.RectanglePacking
 
         public void Rotate()
         {
-            Generic.Swap(ref Size.Width, ref Size.Height);
+            Generic.Swap(ref Size.Width, ref Size.Length);
             IsRotated = !IsRotated;
         }
 
@@ -38,7 +38,7 @@ namespace OpenNest.RectanglePacking
             double minX = items[0].X;
             double minY = items[0].Y;
             double maxX = items[0].X + items[0].Width;
-            double maxY = items[0].Y + items[0].Height;
+            double maxY = items[0].Y + items[0].Length;
 
             foreach (var box in items)
             {

OpenNest.Engine/RectanglePacking/PackFirstFitDecreasing.cs

@@ -16,11 +16,11 @@ namespace OpenNest.RectanglePacking
 
         public override void Pack(List<Item> items)
         {
-            items = items.OrderBy(i => -i.Height).ToList();
+            items = items.OrderBy(i => -i.Length).ToList();
 
             foreach (var item in items)
             {
-                if (item.Height > Bin.Height)
+                if (item.Length > Bin.Length)
                     continue;
 
                 var level = FindLevel(item);
@@ -36,7 +36,7 @@ namespace OpenNest.RectanglePacking
         {
             foreach (var level in levels)
             {
-                if (level.Height < item.Height)
+                if (level.Height < item.Length)
                     continue;
 
                 if (level.RemainingWidth < item.Width)
@@ -58,12 +58,12 @@ namespace OpenNest.RectanglePacking
 
             var remaining = Bin.Top - y;
 
-            if (remaining < item.Height)
+            if (remaining < item.Length)
                 return null;
 
             var level = new Level(Bin);
             level.Y = y;
-            level.Height = item.Height;
+            level.Height = item.Length;
 
             levels.Add(level);
 

OpenNest.IO/DxfExporter.cs

@@ -145,29 +145,29 @@ namespace OpenNest.IO
             {
                 case 1:
                     pt1 = new XYZ(0, 0, 0);
-                    pt2 = new XYZ(0, plate.Size.Height, 0);
+                    pt2 = new XYZ(0, plate.Size.Length, 0);
-                    pt3 = new XYZ(plate.Size.Width, plate.Size.Height, 0);
+                    pt3 = new XYZ(plate.Size.Width, plate.Size.Length, 0);
                     pt4 = new XYZ(plate.Size.Width, 0, 0);
                     break;
 
                 case 2:
                     pt1 = new XYZ(0, 0, 0);
-                    pt2 = new XYZ(0, plate.Size.Height, 0);
+                    pt2 = new XYZ(0, plate.Size.Length, 0);
-                    pt3 = new XYZ(-plate.Size.Width, plate.Size.Height, 0);
+                    pt3 = new XYZ(-plate.Size.Width, plate.Size.Length, 0);
                     pt4 = new XYZ(-plate.Size.Width, 0, 0);
                     break;
 
                 case 3:
                     pt1 = new XYZ(0, 0, 0);
-                    pt2 = new XYZ(0, -plate.Size.Height, 0);
+                    pt2 = new XYZ(0, -plate.Size.Length, 0);
-                    pt3 = new XYZ(-plate.Size.Width, -plate.Size.Height, 0);
+                    pt3 = new XYZ(-plate.Size.Width, -plate.Size.Length, 0);
                     pt4 = new XYZ(-plate.Size.Width, 0, 0);
                     break;
 
                 case 4:
                     pt1 = new XYZ(0, 0, 0);
-                    pt2 = new XYZ(0, -plate.Size.Height, 0);
+                    pt2 = new XYZ(0, -plate.Size.Length, 0);
-                    pt3 = new XYZ(plate.Size.Width, -plate.Size.Height, 0);
+                    pt3 = new XYZ(plate.Size.Width, -plate.Size.Length, 0);
                     pt4 = new XYZ(plate.Size.Width, 0, 0);
                     break;
 

OpenNest.IO/NestFormat.cs

@@ -0,0 +1,126 @@
+using System.Collections.Generic;
+using System.Text.Json;
+
+namespace OpenNest.IO
+{
+    public static class NestFormat
+    {
+        public static readonly JsonSerializerOptions JsonOptions = new()
+        {
+            PropertyNamingPolicy = JsonNamingPolicy.CamelCase,
+            WriteIndented = true
+        };
+
+        public record NestDto
+        {
+            public int Version { get; init; } = 2;
+            public string Name { get; init; } = "";
+            public string Units { get; init; } = "Inches";
+            public string Customer { get; init; } = "";
+            public string DateCreated { get; init; } = "";
+            public string DateLastModified { get; init; } = "";
+            public string Notes { get; init; } = "";
+            public PlateDefaultsDto PlateDefaults { get; init; } = new();
+            public List<DrawingDto> Drawings { get; init; } = new();
+            public List<PlateDto> Plates { get; init; } = new();
+        }
+
+        public record PlateDefaultsDto
+        {
+            public SizeDto Size { get; init; } = new();
+            public double Thickness { get; init; }
+            public int Quadrant { get; init; } = 1;
+            public double PartSpacing { get; init; }
+            public MaterialDto Material { get; init; } = new();
+            public SpacingDto EdgeSpacing { get; init; } = new();
+        }
+
+        public record DrawingDto
+        {
+            public int Id { get; init; }
+            public string Name { get; init; } = "";
+            public string Customer { get; init; } = "";
+            public ColorDto Color { get; init; } = new();
+            public QuantityDto Quantity { get; init; } = new();
+            public int Priority { get; init; }
+            public ConstraintsDto Constraints { get; init; } = new();
+            public MaterialDto Material { get; init; } = new();
+            public SourceDto Source { get; init; } = new();
+        }
+
+        public record PlateDto
+        {
+            public int Id { get; init; }
+            public SizeDto Size { get; init; } = new();
+            public double Thickness { get; init; }
+            public int Quadrant { get; init; } = 1;
+            public int Quantity { get; init; } = 1;
+            public double PartSpacing { get; init; }
+            public MaterialDto Material { get; init; } = new();
+            public SpacingDto EdgeSpacing { get; init; } = new();
+            public List<PartDto> Parts { get; init; } = new();
+        }
+
+        public record PartDto
+        {
+            public int DrawingId { get; init; }
+            public double X { get; init; }
+            public double Y { get; init; }
+            public double Rotation { get; init; }
+        }
+
+        public record SizeDto
+        {
+            public double Width { get; init; }
+            public double Length { get; init; }
+        }
+
+        public record MaterialDto
+        {
+            public string Name { get; init; } = "";
+            public string Grade { get; init; } = "";
+            public double Density { get; init; }
+        }
+
+        public record SpacingDto
+        {
+            public double Left { get; init; }
+            public double Top { get; init; }
+            public double Right { get; init; }
+            public double Bottom { get; init; }
+        }
+
+        public record ColorDto
+        {
+            public int A { get; init; } = 255;
+            public int R { get; init; }
+            public int G { get; init; }
+            public int B { get; init; }
+        }
+
+        public record QuantityDto
+        {
+            public int Required { get; init; }
+        }
+
+        public record ConstraintsDto
+        {
+            public double StepAngle { get; init; }
+            public double StartAngle { get; init; }
+            public double EndAngle { get; init; }
+            public bool Allow180Equivalent { get; init; }
+        }
+
+        public record SourceDto
+        {
+            public string Path { get; init; } = "";
+            public OffsetDto Offset { get; init; } = new();
+        }
+
+        public record OffsetDto
+        {
+            public double X { get; init; }
+            public double Y { get; init; }
+        }
+    }
+}

OpenNest.IO/NestReader.cs

@@ -1,45 +1,28 @@
-using System;
+using System;
 using System.Collections.Generic;
 using System.Drawing;
 using System.IO;
 using System.IO.Compression;
 using System.Linq;
-using System.Text.RegularExpressions;
+using System.Text.Json;
-using System.Xml;
 using OpenNest.CNC;
 using OpenNest.Geometry;
-using OpenNest.Math;
+using static OpenNest.IO.NestFormat;
 
 namespace OpenNest.IO
 {
     public sealed class NestReader
     {
-        private ZipArchive zipArchive;
+        private readonly Stream stream;
-        private Dictionary<int, Plate> plateDict;
+        private readonly ZipArchive zipArchive;
-        private Dictionary<int, Drawing> drawingDict;
-        private Dictionary<int, Program> programDict;
-        private Dictionary<int, Program> plateProgramDict;
-        private Stream stream;
-        private Nest nest;
-
-        private NestReader()
-        {
-            plateDict = new Dictionary<int, Plate>();
-            drawingDict = new Dictionary<int, Drawing>();
-            programDict = new Dictionary<int, Program>();
-            plateProgramDict = new Dictionary<int, Program>();
-            nest = new Nest();
-        }
 
         public NestReader(string file)
-            : this()
         {
             stream = new FileStream(file, FileMode.Open, FileAccess.Read);
             zipArchive = new ZipArchive(stream, ZipArchiveMode.Read);
         }
 
         public NestReader(Stream stream)
-            : this()
         {
             this.stream = stream;
             zipArchive = new ZipArchive(stream, ZipArchiveMode.Read);
@@ -47,52 +30,12 @@ namespace OpenNest.IO
 
         public Nest Read()
         {
-            const string plateExtensionPattern = "plate-\\d\\d\\d";
+            var nestJson = ReadEntry("nest.json");
-            const string programExtensionPattern = "program-\\d\\d\\d";
+            var dto = JsonSerializer.Deserialize<NestDto>(nestJson, JsonOptions);
 
-            foreach (var entry in zipArchive.Entries)
+            var programs = ReadPrograms(dto.Drawings.Count);
-            {
+            var drawingMap = BuildDrawings(dto, programs);
-                var memstream = new MemoryStream();
+            var nest = BuildNest(dto, drawingMap);
-                using (var entryStream = entry.Open())
-                {
-                    entryStream.CopyTo(memstream);
-                }
-
-                memstream.Position = 0;
-
-                switch (entry.FullName)
-                {
-                    case "info":
-                        ReadNestInfo(memstream);
-                        continue;
-
-                    case "drawing-info":
-                        ReadDrawingInfo(memstream);
-                        continue;
-
-                    case "plate-info":
-                        ReadPlateInfo(memstream);
-                        continue;
-                }
-
-                if (Regex.IsMatch(entry.FullName, programExtensionPattern))
-                {
-                    ReadProgram(memstream, entry.FullName);
-                    continue;
-                }
-
-                if (Regex.IsMatch(entry.FullName, plateExtensionPattern))
-                {
-                    ReadPlate(memstream, entry.FullName);
-                    continue;
-                }
-            }
-
-            LinkProgramsToDrawings();
-            LinkPartsToPlates();
-
-            AddPlatesToNest();
-            AddDrawingsToNest();
 
             zipArchive.Dispose();
             stream.Close();
@@ -100,374 +43,114 @@ namespace OpenNest.IO
             return nest;
         }
 
-        private void ReadNestInfo(Stream stream)
+        private string ReadEntry(string name)
         {
-            var reader = XmlReader.Create(stream);
+            var entry = zipArchive.GetEntry(name)
-            var spacing = new Spacing();
+                ?? throw new InvalidDataException($"Nest file is missing required entry '{name}'.");
+            using var entryStream = entry.Open();
+            using var reader = new StreamReader(entryStream);
+            return reader.ReadToEnd();
+        }
 
-            while (reader.Read())
+        private Dictionary<int, Program> ReadPrograms(int count)
+        {
+            var programs = new Dictionary<int, Program>();
+            for (var i = 1; i <= count; i++)
             {
-                if (!reader.IsStartElement())
+                var entry = zipArchive.GetEntry($"programs/program-{i}");
-                    continue;
+                if (entry == null) continue;
 
-                switch (reader.Name)
+                using var entryStream = entry.Open();
+                var memStream = new MemoryStream();
+                entryStream.CopyTo(memStream);
+                memStream.Position = 0;
+
+                var reader = new ProgramReader(memStream);
+                programs[i] = reader.Read();
+            }
+            return programs;
+        }
+
+        private Dictionary<int, Drawing> BuildDrawings(NestDto dto, Dictionary<int, Program> programs)
+        {
+            var map = new Dictionary<int, Drawing>();
+            foreach (var d in dto.Drawings)
+            {
+                var drawing = new Drawing(d.Name);
+                drawing.Customer = d.Customer;
+                drawing.Color = Color.FromArgb(d.Color.A, d.Color.R, d.Color.G, d.Color.B);
+                drawing.Quantity.Required = d.Quantity.Required;
+                drawing.Priority = d.Priority;
+                drawing.Constraints.StepAngle = d.Constraints.StepAngle;
+                drawing.Constraints.StartAngle = d.Constraints.StartAngle;
+                drawing.Constraints.EndAngle = d.Constraints.EndAngle;
+                drawing.Constraints.Allow180Equivalent = d.Constraints.Allow180Equivalent;
+                drawing.Material = new Material(d.Material.Name, d.Material.Grade, d.Material.Density);
+                drawing.Source.Path = d.Source.Path;
+                drawing.Source.Offset = new Vector(d.Source.Offset.X, d.Source.Offset.Y);
+
+                if (programs.TryGetValue(d.Id, out var pgm))
+                    drawing.Program = pgm;
+
+                map[d.Id] = drawing;
+            }
+            return map;
+        }
+
+        private Nest BuildNest(NestDto dto, Dictionary<int, Drawing> drawingMap)
+        {
+            var nest = new Nest();
+            nest.Name = dto.Name;
+
+            Units units;
+            if (Enum.TryParse(dto.Units, true, out units))
+                nest.Units = units;
+
+            nest.Customer = dto.Customer;
+            nest.DateCreated = DateTime.Parse(dto.DateCreated);
+            nest.DateLastModified = DateTime.Parse(dto.DateLastModified);
+            nest.Notes = dto.Notes;
+
+            // Plate defaults
+            var pd = dto.PlateDefaults;
+            nest.PlateDefaults.Size = new OpenNest.Geometry.Size(pd.Size.Width, pd.Size.Length);
+            nest.PlateDefaults.Thickness = pd.Thickness;
+            nest.PlateDefaults.Quadrant = pd.Quadrant;
+            nest.PlateDefaults.PartSpacing = pd.PartSpacing;
+            nest.PlateDefaults.Material = new Material(pd.Material.Name, pd.Material.Grade, pd.Material.Density);
+            nest.PlateDefaults.EdgeSpacing = new Spacing(pd.EdgeSpacing.Left, pd.EdgeSpacing.Bottom, pd.EdgeSpacing.Right, pd.EdgeSpacing.Top);
+
+            // Drawings
+            foreach (var d in drawingMap.OrderBy(k => k.Key))
+                nest.Drawings.Add(d.Value);
+
+            // Plates
+            foreach (var p in dto.Plates.OrderBy(p => p.Id))
+            {
+                var plate = new Plate();
+                plate.Size = new OpenNest.Geometry.Size(p.Size.Width, p.Size.Length);
+                plate.Thickness = p.Thickness;
+                plate.Quadrant = p.Quadrant;
+                plate.Quantity = p.Quantity;
+                plate.PartSpacing = p.PartSpacing;
+                plate.Material = new Material(p.Material.Name, p.Material.Grade, p.Material.Density);
+                plate.EdgeSpacing = new Spacing(p.EdgeSpacing.Left, p.EdgeSpacing.Bottom, p.EdgeSpacing.Right, p.EdgeSpacing.Top);
+
+                foreach (var partDto in p.Parts)
                 {
-                    case "Nest":
+                    if (!drawingMap.TryGetValue(partDto.DrawingId, out var dwg))
-                        nest.Name = reader["name"];
+                        continue;
-                        break;
 
-                    case "Units":
+                    var part = new Part(dwg);
-                        Units units;
+                    part.Rotate(partDto.Rotation);
-                        TryParseEnum<Units>(reader.ReadString(), out units);
+                    part.Offset(new Vector(partDto.X, partDto.Y));
-                        nest.Units = units;
+                    plate.Parts.Add(part);
-                        break;
-
-                    case "Customer":
-                        nest.Customer = reader.ReadString();
-                        break;
-
-                    case "DateCreated":
-                        nest.DateCreated = DateTime.Parse(reader.ReadString());
-                        break;
-
-                    case "DateLastModified":
-                        nest.DateLastModified = DateTime.Parse(reader.ReadString());
-                        break;
-
-                    case "Notes":
-                        nest.Notes = Uri.UnescapeDataString(reader.ReadString());
-                        break;
-
-                    case "Size":
-                        nest.PlateDefaults.Size = OpenNest.Geometry.Size.Parse(reader.ReadString());
-                        break;
-
-                    case "Thickness":
-                        nest.PlateDefaults.Thickness = double.Parse(reader.ReadString());
-                        break;
-
-                    case "Quadrant":
-                        nest.PlateDefaults.Quadrant = int.Parse(reader.ReadString());
-                        break;
-
-                    case "PartSpacing":
-                        nest.PlateDefaults.PartSpacing = double.Parse(reader.ReadString());
-                        break;
-
-                    case "Name":
-                        nest.PlateDefaults.Material.Name = reader.ReadString();
-                        break;
-
-                    case "Grade":
-                        nest.PlateDefaults.Material.Grade = reader.ReadString();
-                        break;
-
-                    case "Density":
-                        nest.PlateDefaults.Material.Density = double.Parse(reader.ReadString());
-                        break;
-
-                    case "Left":
-                        spacing.Left = double.Parse(reader.ReadString());
-                        break;
-
-                    case "Right":
-                        spacing.Right = double.Parse(reader.ReadString());
-                        break;
-
-                    case "Top":
-                        spacing.Top = double.Parse(reader.ReadString());
-                        break;
-
-                    case "Bottom":
-                        spacing.Bottom = double.Parse(reader.ReadString());
-                        break;
                 }
+
+                nest.Plates.Add(plate);
             }
 
-            reader.Close();
+            return nest;
-            nest.PlateDefaults.EdgeSpacing = spacing;
-        }
-
-        private void ReadDrawingInfo(Stream stream)
-        {
-            var reader = XmlReader.Create(stream);
-            Drawing drawing = null;
-
-            while (reader.Read())
-            {
-                if (!reader.IsStartElement())
-                    continue;
-
-                switch (reader.Name)
-                {
-                    case "Drawing":
-                        var id = int.Parse(reader["id"]);
-                        var name = reader["name"];
-
-                        drawingDict.Add(id, (drawing = new Drawing(name)));
-                        break;
-
-                    case "Customer":
-                        drawing.Customer = reader.ReadString();
-                        break;
-
-                    case "Color":
-                        {
-                            var parts = reader.ReadString().Split(',');
-                        
-                            if (parts.Length == 3)
-                            {
-                                byte r = byte.Parse(parts[0]);
-                                byte g = byte.Parse(parts[1]);
-                                byte b = byte.Parse(parts[2]);
-
-                                drawing.Color = Color.FromArgb(r, g, b);
-                            }
-                            else if (parts.Length == 4)
-                            {
-                                byte a = byte.Parse(parts[0]);
-                                byte r = byte.Parse(parts[1]);
-                                byte g = byte.Parse(parts[2]);
-                                byte b = byte.Parse(parts[3]);
-
-                                drawing.Color = Color.FromArgb(a, r, g, b);
-                            }
-                        }
-                        break;
-
-                    case "Required":
-                        drawing.Quantity.Required = int.Parse(reader.ReadString());
-                        break;
-
-                    case "Name":
-                        drawing.Material.Name = reader.ReadString();
-                        break;
-
-                    case "Grade":
-                        drawing.Material.Grade = reader.ReadString();
-                        break;
-
-                    case "Density":
-                        drawing.Material.Density = double.Parse(reader.ReadString());
-                        break;
-
-                    case "Path":
-                        drawing.Source.Path = reader.ReadString();
-                        break;
-
-                    case "Offset":
-                        {
-                            var parts = reader.ReadString().Split(',');
-
-                            if (parts.Length != 2)
-                                continue;
-
-                            drawing.Source.Offset = new Vector(double.Parse(parts[0]), double.Parse(parts[1]));
-                        }
-                        break;
-                }
-            }
-
-            reader.Close();
-        }
-
-        private void ReadPlateInfo(Stream stream)
-        {
-            var reader = XmlReader.Create(stream);
-            var spacing = new Spacing();
-            Plate plate = null;
-
-            while (reader.Read())
-            {
-                if (!reader.IsStartElement())
-                    continue;
-
-                switch (reader.Name)
-                {
-                    case "Plate":
-                        var id = int.Parse(reader["id"]);
-
-                        if (plate != null)
-                            plate.EdgeSpacing = spacing;
-
-                        plateDict.Add(id, (plate = new Plate()));
-                        break;
-
-                    case "Size":
-                        plate.Size = OpenNest.Geometry.Size.Parse(reader.ReadString());
-                        break;
-
-                    case "Qty":
-                        plate.Quantity = int.Parse(reader.ReadString());
-                        break;
-
-                    case "Thickness":
-                        plate.Thickness = double.Parse(reader.ReadString());
-                        break;
-
-                    case "Quadrant":
-                        plate.Quadrant = int.Parse(reader.ReadString());
-                        break;
-
-                    case "PartSpacing":
-                        plate.PartSpacing = double.Parse(reader.ReadString());
-                        break;
-
-                    case "Name":
-                        plate.Material.Name = reader.ReadString();
-                        break;
-
-                    case "Grade":
-                        plate.Material.Grade = reader.ReadString();
-                        break;
-
-                    case "Density":
-                        plate.Material.Density = double.Parse(reader.ReadString());
-                        break;
-
-                    case "Left":
-                        spacing.Left = double.Parse(reader.ReadString());
-                        break;
-
-                    case "Right":
-                        spacing.Right = double.Parse(reader.ReadString());
-                        break;
-
-                    case "Top":
-                        spacing.Top = double.Parse(reader.ReadString());
-                        break;
-
-                    case "Bottom":
-                        spacing.Bottom = double.Parse(reader.ReadString());
-                        break;
-                }
-            }
-
-            if (plate != null)
-                plate.EdgeSpacing = spacing;
-        }
-
-        private void ReadProgram(Stream stream, string name)
-        {
-            var id = GetProgramId(name);
-            var reader = new ProgramReader(stream);
-            var pgm = reader.Read();
-            programDict.Add(id, pgm);
-        }
-
-        private void ReadPlate(Stream stream, string name)
-        {
-            var id = GetPlateId(name);
-            var reader = new ProgramReader(stream);
-            var pgm = reader.Read();
-            plateProgramDict.Add(id, pgm);
-        }
-
-        private void LinkProgramsToDrawings()
-        {
-            foreach (var drawingItem in drawingDict)
-            {
-                Program pgm;
-
-                if (programDict.TryGetValue(drawingItem.Key, out pgm))
-                    drawingItem.Value.Program = pgm;
-            }
-        }
-
-        private void LinkPartsToPlates()
-        {
-            foreach (var plateProgram in plateProgramDict)
-            {
-                var parts = CreateParts(plateProgram.Value);
-
-                Plate plate;
-
-                if (!plateDict.TryGetValue(plateProgram.Key, out plate))
-                    plate = new Plate();
-
-                plate.Parts.AddRange(parts);
-                plateDict[plateProgram.Key] = plate;
-            }
-        }
-
-        private void AddPlatesToNest()
-        {
-            var plates = plateDict.OrderBy(i => i.Key).Select(i => i.Value).ToList();
-            nest.Plates.AddRange(plates);
-        }
-
-        private void AddDrawingsToNest()
-        {
-            var drawings = drawingDict.OrderBy(i => i.Key).Select(i => i.Value).ToList();
-            drawings.ForEach(d => nest.Drawings.Add(d));
-        }
-
-        private List<Part> CreateParts(Program pgm)
-        {
-            var parts = new List<Part>();
-            var pos = Vector.Zero;
-
-            for (int i = 0; i < pgm.Codes.Count; i++)
-            {
-                var code = pgm.Codes[i];
-
-                switch (code.Type)
-                {
-                    case CodeType.RapidMove:
-                        pos = ((RapidMove)code).EndPoint;
-                        break;
-
-                    case CodeType.SubProgramCall:
-                        var subpgm = (SubProgramCall)code;
-                        var dwg = drawingDict[subpgm.Id];
-                        var part = new Part(dwg);
-                        part.Rotate(Angle.ToRadians(subpgm.Rotation));
-                        part.Offset(pos);
-                        parts.Add(part);
-                        break;
-                }
-            }
-
-            return parts;
-        }
-
-        private int GetPlateId(string name)
-        {
-            return int.Parse(name.Replace("plate-", ""));
-        }
-
-        private int GetProgramId(string name)
-        {
-            return int.Parse(name.Replace("program-", ""));
-        }
-
-        public static T ParseEnum<T>(string value)
-        {
-            return (T)Enum.Parse(typeof(T), value, true);
-        }
-
-        public static bool TryParseEnum<T>(string value, out T e)
-        {
-            try
-            {
-                e = ParseEnum<T>(value);
-                return true;
-            }
-            catch
-            {
-                e = ParseEnum<T>(typeof(T).GetEnumValues().GetValue(0).ToString());
-            }
-
-            return false;
-        }
-
-        private enum NestInfoSection
-        {
-            None,
-            DefaultPlate,
-            Material,
-            EdgeSpacing,
-            Source
         }
     }
 }

OpenNest.IO/NestWriter.cs

@@ -1,32 +1,22 @@
-using System;
+using System;
 using System.Collections.Generic;
 using System.IO;
 using System.IO.Compression;
 using System.Linq;
 using System.Text;
-using System.Xml;
+using System.Text.Json;
 using OpenNest.CNC;
 using OpenNest.Math;
+using static OpenNest.IO.NestFormat;
 
 namespace OpenNest.IO
 {
     public sealed class NestWriter
     {
-        /// <summary>
-        /// Number of decimal places the output is round to.
-        /// This number must have more decimal places than Tolerance.Epsilon
-        /// </summary>
         private const int OutputPrecision = 10;
-
-        /// <summary>
-        /// Fixed-point format string that avoids scientific notation.
-        /// ProgramReader treats 'E' as a code letter, so "6.66E-08" would be
-        /// split into X:"6.66" and E:"-08", corrupting the parsed value.
-        /// </summary>
         private const string CoordinateFormat = "0.##########";
 
         private readonly Nest nest;
-        private ZipArchive zipArchive;
         private Dictionary<int, Drawing> drawingDict;
 
         public NestWriter(Nest nest)
@@ -37,27 +27,21 @@ namespace OpenNest.IO
 
         public bool Write(string file)
         {
-            this.nest.DateLastModified = DateTime.Now;
+            nest.DateLastModified = DateTime.Now;
-
             SetDrawingIds();
 
-            using (var fileStream = new FileStream(file, FileMode.Create))
+            using var fileStream = new FileStream(file, FileMode.Create);
-            using (zipArchive = new ZipArchive(fileStream, ZipArchiveMode.Create))
+            using var zipArchive = new ZipArchive(fileStream, ZipArchiveMode.Create);
-            {
+
-                AddNestInfo();
+            WriteNestJson(zipArchive);
-                AddPlates();
+            WritePrograms(zipArchive);
-                AddPlateInfo();
-                AddDrawings();
-                AddDrawingInfo();
-            }
 
             return true;
         }
 
         private void SetDrawingIds()
         {
-            int id = 1;
+            var id = 1;
-
             foreach (var drawing in nest.Drawings)
             {
                 drawingDict.Add(id, drawing);
@@ -65,241 +49,156 @@ namespace OpenNest.IO
             }
         }
 
-        private void AddNestInfo()
+        private void WriteNestJson(ZipArchive zipArchive)
         {
-            var stream = new MemoryStream();
+            var dto = BuildNestDto();
-            var writer = XmlWriter.Create(stream, new XmlWriterSettings()
+            var json = JsonSerializer.Serialize(dto, JsonOptions);
-            {
-                Indent = true
-            });
 
-            writer.WriteStartDocument();
+            var entry = zipArchive.CreateEntry("nest.json");
-            writer.WriteStartElement("Nest");
+            using var stream = entry.Open();
-            writer.WriteAttributeString("name", nest.Name);
+            using var writer = new StreamWriter(stream, Encoding.UTF8);
-
+            writer.Write(json);
-            writer.WriteElementString("Units", nest.Units.ToString());
-            writer.WriteElementString("Customer", nest.Customer);
-            writer.WriteElementString("DateCreated", nest.DateCreated.ToString());
-            writer.WriteElementString("DateLastModified", nest.DateLastModified.ToString());
-
-            writer.WriteStartElement("DefaultPlate");
-            writer.WriteElementString("Size", nest.PlateDefaults.Size.ToString());
-            writer.WriteElementString("Thickness", nest.PlateDefaults.Thickness.ToString());
-            writer.WriteElementString("Quadrant", nest.PlateDefaults.Quadrant.ToString());
-            writer.WriteElementString("PartSpacing", nest.PlateDefaults.PartSpacing.ToString());
-
-            writer.WriteStartElement("Material");
-            writer.WriteElementString("Name", nest.PlateDefaults.Material.Name);
-            writer.WriteElementString("Grade", nest.PlateDefaults.Material.Grade);
-            writer.WriteElementString("Density", nest.PlateDefaults.Material.Density.ToString());
-            writer.WriteEndElement();
-
-            writer.WriteStartElement("EdgeSpacing");
-            writer.WriteElementString("Left", nest.PlateDefaults.EdgeSpacing.Left.ToString());
-            writer.WriteElementString("Top", nest.PlateDefaults.EdgeSpacing.Top.ToString());
-            writer.WriteElementString("Right", nest.PlateDefaults.EdgeSpacing.Right.ToString());
-            writer.WriteElementString("Bottom", nest.PlateDefaults.EdgeSpacing.Bottom.ToString());
-            writer.WriteEndElement();
-
-            writer.WriteElementString("Notes", Uri.EscapeDataString(nest.Notes));
-
-            writer.WriteEndElement(); // DefaultPlate
-            writer.WriteEndElement(); // Nest
-
-            writer.WriteEndDocument();
-
-            writer.Flush();
-            writer.Close();
-
-            stream.Position = 0;
-
-            var entry = zipArchive.CreateEntry("info");
-            using (var entryStream = entry.Open())
-            {
-                stream.CopyTo(entryStream);
-            }
         }
 
-        private void AddPlates()
+        private NestDto BuildNestDto()
         {
-            int num = 1;
+            return new NestDto
-
-            foreach (var plate in nest.Plates)
             {
-                var stream = new MemoryStream();
+                Version = 2,
-                var name = string.Format("plate-{0}", num.ToString().PadLeft(3, '0'));
+                Name = nest.Name ?? "",
+                Units = nest.Units.ToString(),
+                Customer = nest.Customer ?? "",
+                DateCreated = nest.DateCreated.ToString("o"),
+                DateLastModified = nest.DateLastModified.ToString("o"),
+                Notes = nest.Notes ?? "",
+                PlateDefaults = BuildPlateDefaultsDto(),
+                Drawings = BuildDrawingDtos(),
+                Plates = BuildPlateDtos()
+            };
+        }
 
-                WritePlate(stream, plate);
+        private PlateDefaultsDto BuildPlateDefaultsDto()
-
+        {
-                var entry = zipArchive.CreateEntry(name);
+            var pd = nest.PlateDefaults;
-                using (var entryStream = entry.Open())
+            return new PlateDefaultsDto
+            {
+                Size = new SizeDto { Width = pd.Size.Width, Length = pd.Size.Length },
+                Thickness = pd.Thickness,
+                Quadrant = pd.Quadrant,
+                PartSpacing = pd.PartSpacing,
+                Material = new MaterialDto
                 {
-                    stream.CopyTo(entryStream);
+                    Name = pd.Material.Name ?? "",
+                    Grade = pd.Material.Grade ?? "",
+                    Density = pd.Material.Density
+                },
+                EdgeSpacing = new SpacingDto
+                {
+                    Left = pd.EdgeSpacing.Left,
+                    Top = pd.EdgeSpacing.Top,
+                    Right = pd.EdgeSpacing.Right,
+                    Bottom = pd.EdgeSpacing.Bottom
                 }
-
+            };
-                num++;
-            }
         }
 
-        private void AddPlateInfo()
+        private List<DrawingDto> BuildDrawingDtos()
         {
-            var stream = new MemoryStream();
+            var list = new List<DrawingDto>();
-            var writer = XmlWriter.Create(stream, new XmlWriterSettings()
+            foreach (var kvp in drawingDict.OrderBy(k => k.Key))
             {
-                Indent = true
+                var d = kvp.Value;
-            });
+                list.Add(new DrawingDto
+                {
+                    Id = kvp.Key,
+                    Name = d.Name ?? "",
+                    Customer = d.Customer ?? "",
+                    Color = new ColorDto { A = d.Color.A, R = d.Color.R, G = d.Color.G, B = d.Color.B },
+                    Quantity = new QuantityDto { Required = d.Quantity.Required },
+                    Priority = d.Priority,
+                    Constraints = new ConstraintsDto
+                    {
+                        StepAngle = d.Constraints.StepAngle,
+                        StartAngle = d.Constraints.StartAngle,
+                        EndAngle = d.Constraints.EndAngle,
+                        Allow180Equivalent = d.Constraints.Allow180Equivalent
+                    },
+                    Material = new MaterialDto
+                    {
+                        Name = d.Material.Name ?? "",
+                        Grade = d.Material.Grade ?? "",
+                        Density = d.Material.Density
+                    },
+                    Source = new SourceDto
+                    {
+                        Path = d.Source.Path ?? "",
+                        Offset = new OffsetDto { X = d.Source.Offset.X, Y = d.Source.Offset.Y }
+                    }
+                });
+            }
+            return list;
+        }
 
-            writer.WriteStartDocument();
+        private List<PlateDto> BuildPlateDtos()
-            writer.WriteStartElement("Plates");
+        {
-            writer.WriteAttributeString("count", nest.Plates.Count.ToString());
+            var list = new List<PlateDto>();
-
+            for (var i = 0; i < nest.Plates.Count; i++)
-            for (int i = 0; i < nest.Plates.Count; ++i)
             {
                 var plate = nest.Plates[i];
-
+                var parts = new List<PartDto>();
-                writer.WriteStartElement("Plate");
+                foreach (var part in plate.Parts)
-                writer.WriteAttributeString("id", (i + 1).ToString());
-
-                writer.WriteElementString("Quadrant", plate.Quadrant.ToString());
-                writer.WriteElementString("Thickness", plate.Thickness.ToString());
-                writer.WriteElementString("Size", plate.Size.ToString());
-                writer.WriteElementString("Qty", plate.Quantity.ToString());
-                writer.WriteElementString("PartSpacing", plate.PartSpacing.ToString());
-
-                writer.WriteStartElement("Material");
-                writer.WriteElementString("Name", plate.Material.Name);
-                writer.WriteElementString("Grade", plate.Material.Grade);
-                writer.WriteElementString("Density", plate.Material.Density.ToString());
-                writer.WriteEndElement();
-
-                writer.WriteStartElement("EdgeSpacing");
-                writer.WriteElementString("Left", plate.EdgeSpacing.Left.ToString());
-                writer.WriteElementString("Top", plate.EdgeSpacing.Top.ToString());
-                writer.WriteElementString("Right", plate.EdgeSpacing.Right.ToString());
-                writer.WriteElementString("Bottom", plate.EdgeSpacing.Bottom.ToString());
-                writer.WriteEndElement();
-
-                writer.WriteEndElement(); // Plate
-                writer.Flush();
-            }
-
-            writer.WriteEndElement(); // Plates
-            writer.WriteEndDocument();
-
-            writer.Flush();
-            writer.Close();
-
-            stream.Position = 0;
-
-            var entry = zipArchive.CreateEntry("plate-info");
-            using (var entryStream = entry.Open())
-            {
-                stream.CopyTo(entryStream);
-            }
-        }
-
-        private void AddDrawings()
-        {
-            int num = 1;
-
-            foreach (var dwg in nest.Drawings)
-            {
-                var stream = new MemoryStream();
-                var name = string.Format("program-{0}", num.ToString().PadLeft(3, '0'));
-
-                WriteDrawing(stream, dwg);
-
-                var entry = zipArchive.CreateEntry(name);
-                using (var entryStream = entry.Open())
                 {
-                    stream.CopyTo(entryStream);
+                    var match = drawingDict.Where(dwg => dwg.Value == part.BaseDrawing).FirstOrDefault();
+                    parts.Add(new PartDto
+                    {
+                        DrawingId = match.Key,
+                        X = part.Location.X,
+                        Y = part.Location.Y,
+                        Rotation = part.Rotation
+                    });
                 }
 
-                num++;
+                list.Add(new PlateDto
+                {
+                    Id = i + 1,
+                    Size = new SizeDto { Width = plate.Size.Width, Length = plate.Size.Length },
+                    Thickness = plate.Thickness,
+                    Quadrant = plate.Quadrant,
+                    Quantity = plate.Quantity,
+                    PartSpacing = plate.PartSpacing,
+                    Material = new MaterialDto
+                    {
+                        Name = plate.Material.Name ?? "",
+                        Grade = plate.Material.Grade ?? "",
+                        Density = plate.Material.Density
+                    },
+                    EdgeSpacing = new SpacingDto
+                    {
+                        Left = plate.EdgeSpacing.Left,
+                        Top = plate.EdgeSpacing.Top,
+                        Right = plate.EdgeSpacing.Right,
+                        Bottom = plate.EdgeSpacing.Bottom
+                    },
+                    Parts = parts
+                });
             }
+            return list;
         }
 
-        private void AddDrawingInfo()
+        private void WritePrograms(ZipArchive zipArchive)
         {
-            var stream = new MemoryStream();
+            foreach (var kvp in drawingDict.OrderBy(k => k.Key))
-            var writer = XmlWriter.Create(stream, new XmlWriterSettings()
             {
-                Indent = true
+                var name = $"programs/program-{kvp.Key}";
-            });
+                var stream = new MemoryStream();
+                WriteDrawing(stream, kvp.Value);
 
-            writer.WriteStartDocument();
+                var entry = zipArchive.CreateEntry(name);
-            writer.WriteStartElement("Drawings");
+                using var entryStream = entry.Open();
-            writer.WriteAttributeString("count", nest.Drawings.Count.ToString());
-
-            int id = 1;
-
-            foreach (var drawing in nest.Drawings)
-            {
-                writer.WriteStartElement("Drawing");
-                writer.WriteAttributeString("id", id.ToString());
-                writer.WriteAttributeString("name", drawing.Name);
-
-                writer.WriteElementString("Customer", drawing.Customer);
-                writer.WriteElementString("Color", string.Format("{0}, {1}, {2}, {3}", drawing.Color.A, drawing.Color.R, drawing.Color.G, drawing.Color.B));
-
-                writer.WriteStartElement("Quantity");
-                writer.WriteElementString("Required", drawing.Quantity.Required.ToString());
-                writer.WriteElementString("Nested", drawing.Quantity.Nested.ToString());
-                writer.WriteEndElement();
-
-                writer.WriteStartElement("Material");
-                writer.WriteElementString("Name", drawing.Material.Name);
-                writer.WriteElementString("Grade", drawing.Material.Grade);
-                writer.WriteElementString("Density", drawing.Material.Density.ToString());
-                writer.WriteEndElement();
-
-                writer.WriteStartElement("Source");
-                writer.WriteElementString("Path", drawing.Source.Path);
-                writer.WriteElementString("Offset", string.Format("{0}, {1}", 
-                    drawing.Source.Offset.X, 
-                    drawing.Source.Offset.Y));
-                writer.WriteEndElement(); // Source
-
-                writer.WriteEndElement(); // Drawing
-
-                id++;
-            }
-
-            writer.WriteEndElement(); // Drawings
-            writer.WriteEndDocument();
-
-            writer.Flush();
-            writer.Close();
-
-            stream.Position = 0;
-
-            var entry = zipArchive.CreateEntry("drawing-info");
-            using (var entryStream = entry.Open())
-            {
                 stream.CopyTo(entryStream);
             }
         }
 
-        private void WritePlate(Stream stream, Plate plate)
-        {
-            var writer = new StreamWriter(stream);
-            writer.AutoFlush = true;
-            writer.WriteLine("G90");
-
-            foreach (var part in plate.Parts)
-            {
-                var match = drawingDict.Where(dwg => dwg.Value == part.BaseDrawing).FirstOrDefault();
-                var id = match.Key;
-
-                writer.WriteLine("G00X{0}Y{1}",
-                    part.Location.X.ToString(CoordinateFormat),
-                    part.Location.Y.ToString(CoordinateFormat));
-                writer.WriteLine("G65P{0}R{1}", id, Angle.ToDegrees(part.Rotation));
-            }
-
-            stream.Position = 0;
-        }
-
         private void WriteDrawing(Stream stream, Drawing drawing)
         {
             var program = drawing.Program;
@@ -308,7 +207,7 @@ namespace OpenNest.IO
 
             writer.WriteLine(program.Mode == Mode.Absolute ? "G90" : "G91");
 
-            for (int i = 0; i < drawing.Program.Length; ++i)
+            for (var i = 0; i < drawing.Program.Length; ++i)
             {
                 var code = drawing.Program[i];
                 writer.WriteLine(GetCodeString(code));

OpenNest.Mcp/Tools/InputTools.cs

@@ -40,10 +40,10 @@ namespace OpenNest.Mcp.Tools
             {
                 var plate = nest.Plates[i];
                 var work = plate.WorkArea();
-                sb.AppendLine($"  Plate {i}: {plate.Size.Width:F1} x {plate.Size.Height:F1}, " +
+                sb.AppendLine($"  Plate {i}: {plate.Size.Width:F1} x {plate.Size.Length:F1}, " +
                               $"parts={plate.Parts.Count}, " +
                               $"utilization={plate.Utilization():P1}, " +
-                              $"work area={work.Width:F1} x {work.Height:F1}");
+                              $"work area={work.Width:F1} x {work.Length:F1}");
             }
 
             sb.AppendLine($"Drawings: {nest.Drawings.Count}");
@@ -51,7 +51,7 @@ namespace OpenNest.Mcp.Tools
             foreach (var dwg in nest.Drawings)
             {
                 var bbox = dwg.Program.BoundingBox();
-                sb.AppendLine($"  {dwg.Name}: bbox={bbox.Width:F2} x {bbox.Height:F2}, " +
+                sb.AppendLine($"  {dwg.Name}: bbox={bbox.Width:F2} x {bbox.Length:F2}, " +
                               $"required={dwg.Quantity.Required}, nested={dwg.Quantity.Nested}");
             }
 
@@ -85,7 +85,7 @@ namespace OpenNest.Mcp.Tools
             _session.Drawings.Add(drawing);
 
             var bbox = pgm.BoundingBox();
-            return $"Imported drawing '{drawingName}': bbox={bbox.Width:F2} x {bbox.Height:F2}";
+            return $"Imported drawing '{drawingName}': bbox={bbox.Width:F2} x {bbox.Length:F2}";
         }
 
         [McpServerTool(Name = "create_drawing")]
@@ -134,7 +134,7 @@ namespace OpenNest.Mcp.Tools
             _session.Drawings.Add(drawing);
 
             var bbox = pgm.BoundingBox();
-            return $"Created drawing '{name}': bbox={bbox.Width:F2} x {bbox.Height:F2}";
+            return $"Created drawing '{name}': bbox={bbox.Width:F2} x {bbox.Length:F2}";
         }
 
         private static CncProgram CreateRectangle(double width, double height)

OpenNest.Mcp/Tools/InspectionTools.cs

@@ -32,13 +32,13 @@ namespace OpenNest.Mcp.Tools
 
             var sb = new StringBuilder();
             sb.AppendLine($"Plate {plateIndex}:");
-            sb.AppendLine($"  Size: {plate.Size.Width:F1} x {plate.Size.Height:F1}");
+            sb.AppendLine($"  Size: {plate.Size.Width:F1} x {plate.Size.Length:F1}");
             sb.AppendLine($"  Quadrant: {plate.Quadrant}");
             sb.AppendLine($"  Thickness: {plate.Thickness:F2}");
             sb.AppendLine($"  Material: {plate.Material.Name}");
             sb.AppendLine($"  Part spacing: {plate.PartSpacing:F2}");
             sb.AppendLine($"  Edge spacing: L={plate.EdgeSpacing.Left:F2} B={plate.EdgeSpacing.Bottom:F2} R={plate.EdgeSpacing.Right:F2} T={plate.EdgeSpacing.Top:F2}");
-            sb.AppendLine($"  Work area: {work.X:F1},{work.Y:F1} {work.Width:F1}x{work.Height:F1}");
+            sb.AppendLine($"  Work area: {work.X:F1},{work.Y:F1} {work.Width:F1}x{work.Length:F1}");
             sb.AppendLine($"  Parts: {plate.Parts.Count}");
             sb.AppendLine($"  Utilization: {plate.Utilization():P1}");
             sb.AppendLine($"  Quantity: {plate.Quantity}");
@@ -57,7 +57,7 @@ namespace OpenNest.Mcp.Tools
             for (var i = 0; i < remnants.Count; i++)
             {
                 var r = remnants[i];
-                sb.AppendLine($"    Remnant {i}: ({r.X:F1},{r.Y:F1}) {r.Width:F1}x{r.Height:F1}, area={r.Area():F1}");
+                sb.AppendLine($"    Remnant {i}: ({r.X:F1},{r.Y:F1}) {r.Width:F1}x{r.Length:F1}, area={r.Area():F1}");
             }
 
             return sb.ToString();
@@ -90,7 +90,7 @@ namespace OpenNest.Mcp.Tools
                 sb.AppendLine($"  [{i}] {part.BaseDrawing.Name}: " +
                               $"loc=({part.Location.X:F2},{part.Location.Y:F2}), " +
                               $"rot={rotDeg:F1} deg, " +
-                              $"bbox=({bbox.X:F2},{bbox.Y:F2} {bbox.Width:F2}x{bbox.Height:F2})");
+                              $"bbox=({bbox.X:F2},{bbox.Y:F2} {bbox.Width:F2}x{bbox.Length:F2})");
             }
 
             if (plate.Parts.Count > limit)

OpenNest.Mcp/Tools/NestingTools.cs

@@ -121,7 +121,7 @@ namespace OpenNest.Mcp.Tools
                 var added = plate.Parts.Count - countBefore;
                 totalAdded += added;
 
-                sb.AppendLine($"  Remnant {i}: ({remnant.X:F1},{remnant.Y:F1} {remnant.Width:F1}x{remnant.Height:F1}) -> {added} parts {(success ? "" : "(no fit)")}");
+                sb.AppendLine($"  Remnant {i}: ({remnant.X:F1},{remnant.Y:F1} {remnant.Width:F1}x{remnant.Length:F1}) -> {added} parts {(success ? "" : "(no fit)")}");
             }
 
             sb.AppendLine($"Total parts added: {totalAdded}");

OpenNest.Mcp/Tools/SetupTools.cs

@@ -41,11 +41,11 @@ namespace OpenNest.Mcp.Tools
             var work = plate.WorkArea();
 
             var sb = new StringBuilder();
-            sb.AppendLine($"Created plate {index}: {plate.Size.Width:F1} x {plate.Size.Height:F1}");
+            sb.AppendLine($"Created plate {index}: {plate.Size.Width:F1} x {plate.Size.Length:F1}");
             sb.AppendLine($"  Quadrant: {plate.Quadrant}");
             sb.AppendLine($"  Part spacing: {plate.PartSpacing:F2}");
             sb.AppendLine($"  Edge spacing: L={plate.EdgeSpacing.Left:F2} B={plate.EdgeSpacing.Bottom:F2} R={plate.EdgeSpacing.Right:F2} T={plate.EdgeSpacing.Top:F2}");
-            sb.AppendLine($"  Work area: {work.Width:F1} x {work.Height:F1}");
+            sb.AppendLine($"  Work area: {work.Width:F1} x {work.Length:F1}");
 
             return sb.ToString();
         }

OpenNest/Actions/ActionSelectArea.cs

@@ -95,7 +95,7 @@ namespace OpenNest.Actions
             var location = plateView.PointWorldToGraph(SelectedArea.Location);
             var size = new SizeF(
                 plateView.LengthWorldToGui(SelectedArea.Width), 
-                plateView.LengthWorldToGui(SelectedArea.Height));
+                plateView.LengthWorldToGui(SelectedArea.Length));
 
             var rect = new System.Drawing.RectangleF(location.X, location.Y - size.Height, size.Width, size.Height);
 

OpenNest/Controls/DrawControl.cs

@@ -205,7 +205,7 @@ namespace OpenNest.Controls
 
         public virtual void ZoomToArea(Box box, bool redraw = true)
         {
-            ZoomToArea(box.X, box.Y, box.Width, box.Height, redraw);
+            ZoomToArea(box.X, box.Y, box.Width, box.Length, redraw);
         }
 
         public virtual void ZoomToArea(double x, double y, double width, double height, bool redraw = true)

OpenNest/Controls/PlateView.cs

@@ -384,13 +384,13 @@ namespace OpenNest.Controls
             var plateRect = new RectangleF
             {
                 Width = LengthWorldToGui(Plate.Size.Width),
-                Height = LengthWorldToGui(Plate.Size.Height)
+                Height = LengthWorldToGui(Plate.Size.Length)
             };
 
             var edgeSpacingRect = new RectangleF
             {
                 Width = LengthWorldToGui(Plate.Size.Width - Plate.EdgeSpacing.Left - Plate.EdgeSpacing.Right),
-                Height = LengthWorldToGui(Plate.Size.Height - Plate.EdgeSpacing.Top - Plate.EdgeSpacing.Bottom)
+                Height = LengthWorldToGui(Plate.Size.Length - Plate.EdgeSpacing.Top - Plate.EdgeSpacing.Bottom)
             };
 
             switch (Plate.Quadrant)
@@ -410,17 +410,17 @@ namespace OpenNest.Controls
                     break;
 
                 case 3:
-                    plateRect.Location = PointWorldToGraph(-Plate.Size.Width, -Plate.Size.Height);
+                    plateRect.Location = PointWorldToGraph(-Plate.Size.Width, -Plate.Size.Length);
                     edgeSpacingRect.Location = PointWorldToGraph(
                         Plate.EdgeSpacing.Left - Plate.Size.Width,
-                        Plate.EdgeSpacing.Bottom - Plate.Size.Height);
+                        Plate.EdgeSpacing.Bottom - Plate.Size.Length);
                     break;
 
                 case 4:
-                    plateRect.Location = PointWorldToGraph(0, -Plate.Size.Height);
+                    plateRect.Location = PointWorldToGraph(0, -Plate.Size.Length);
                     edgeSpacingRect.Location = PointWorldToGraph(
                         Plate.EdgeSpacing.Left,
-                        Plate.EdgeSpacing.Bottom - Plate.Size.Height);
+                        Plate.EdgeSpacing.Bottom - Plate.Size.Length);
                     break;
 
                 default:
@@ -590,7 +590,7 @@ namespace OpenNest.Controls
             {
                 Location = PointWorldToGraph(box.Location),
                 Width = LengthWorldToGui(box.Width),
-                Height = LengthWorldToGui(box.Height)
+                Height = LengthWorldToGui(box.Length)
             };
 
             g.DrawRectangle(ColorScheme.BoundingBoxPen, rect.X, rect.Y - rect.Height, rect.Width, rect.Height);

OpenNest/Forms/BestFitViewerForm.cs

@@ -56,7 +56,7 @@ namespace OpenNest.Forms
             var sw = Stopwatch.StartNew();
 
             var results = BestFitCache.GetOrCompute(
-                drawing, plate.Size.Width, plate.Size.Height, plate.PartSpacing);
+                drawing, plate.Size.Width, plate.Size.Length, plate.PartSpacing);
 
             var findMs = sw.ElapsedMilliseconds;
             var total = results.Count;

OpenNest/Forms/CadConverterForm.cs

@@ -112,7 +112,7 @@ namespace OpenNest.Forms
                 drawing.Source.Path = item.Path;
                 drawing.Quantity.Required = item.Quantity;
 
-                var shape = new DefinedShape(entities);
+                var shape = new ShapeProfile(entities);
 
                 SetRotation(shape.Perimeter, RotationType.CW);
 

OpenNest/Forms/EditNestInfoForm.cs

@@ -173,7 +173,7 @@ namespace OpenNest.Forms
                 return;
             }
 
-            if (TopSpacing + BottomSpacing >= size.Height)
+            if (TopSpacing + BottomSpacing >= size.Length)
             {
                 applyButton.Enabled = false;
                 return;

OpenNest/Forms/EditPlateForm.cs

@@ -145,7 +145,7 @@ namespace OpenNest.Forms
                 return;
             }
 
-            if (TopSpacing + BottomSpacing >= size.Height)
+            if (TopSpacing + BottomSpacing >= size.Length)
             {
                 applyButton.Enabled = false;
                 return;

OpenNest/Forms/MainForm.cs

@@ -43,8 +43,8 @@ namespace OpenNest.Forms
             UpdateStatus();
             UpdateGpuStatus();
 
-            if (GpuEvaluatorFactory.GpuAvailable)
+            //if (GpuEvaluatorFactory.GpuAvailable)
-                BestFitCache.CreateEvaluator = (drawing, spacing) => GpuEvaluatorFactory.Create(drawing, spacing);
+            //    BestFitCache.CreateEvaluator = (drawing, spacing) => GpuEvaluatorFactory.Create(drawing, spacing);
         }
 
         private string GetNestName(DateTime date, int id)

docs/superpowers/plans/2026-03-12-nest-file-format-v2.md

@@ -0,0 +1,767 @@
+# Nest File Format v2 Implementation Plan
+
+> **For agentic workers:** REQUIRED: Use superpowers:subagent-driven-development (if subagents available) or superpowers:executing-plans to implement this plan. Steps use checkbox (`- [ ]`) syntax for tracking.
+
+**Goal:** Replace the XML+G-code nest file format with a single `nest.json` metadata file plus `programs/` folder inside the ZIP archive.
+
+**Architecture:** Add a `NestFormat` static class containing DTO records and shared JSON options. Rewrite `NestWriter` to serialize DTOs to JSON and write programs under `programs/`. Rewrite `NestReader` to deserialize JSON and read programs from `programs/`. Public API unchanged.
+
+**Tech Stack:** `System.Text.Json` (built into .NET 8, no new packages needed)
+
+**Spec:** `docs/superpowers/specs/2026-03-12-nest-file-format-v2-design.md`
+
+---
+
+## File Structure
+
+| Action | File | Responsibility |
+|--------|------|----------------|
+| Create | `OpenNest.IO/NestFormat.cs` | DTO records for JSON serialization + shared `JsonSerializerOptions` |
+| Rewrite | `OpenNest.IO/NestWriter.cs` | Serialize nest to JSON + write programs to `programs/` folder |
+| Rewrite | `OpenNest.IO/NestReader.cs` | Deserialize JSON + read programs from `programs/` folder |
+
+No other files change. `ProgramReader.cs`, `DxfImporter.cs`, `DxfExporter.cs`, `Extensions.cs`, all domain model classes, and all caller sites remain untouched.
+
+---
+
+## Chunk 1: DTO Records and JSON Options
+
+### Task 1: Create NestFormat.cs with DTO records
+
+**Files:**
+- Create: `OpenNest.IO/NestFormat.cs`
+
+These DTOs are the JSON shape — flat records that map 1:1 with the spec's JSON schema. They live in `OpenNest.IO` because they're serialization concerns, not domain model.
+
+- [ ] **Step 1: Create `NestFormat.cs`**
+
+```csharp
+using System.Text.Json;
+
+namespace OpenNest.IO
+{
+    public static class NestFormat
+    {
+        public static readonly JsonSerializerOptions JsonOptions = new()
+        {
+            PropertyNamingPolicy = JsonNamingPolicy.CamelCase,
+            WriteIndented = true
+        };
+
+        public record NestDto
+        {
+            public int Version { get; init; } = 2;
+            public string Name { get; init; } = "";
+            public string Units { get; init; } = "Inches";
+            public string Customer { get; init; } = "";
+            public string DateCreated { get; init; } = "";
+            public string DateLastModified { get; init; } = "";
+            public string Notes { get; init; } = "";
+            public PlateDefaultsDto PlateDefaults { get; init; } = new();
+            public List<DrawingDto> Drawings { get; init; } = new();
+            public List<PlateDto> Plates { get; init; } = new();
+        }
+
+        public record PlateDefaultsDto
+        {
+            public SizeDto Size { get; init; } = new();
+            public double Thickness { get; init; }
+            public int Quadrant { get; init; } = 1;
+            public double PartSpacing { get; init; }
+            public MaterialDto Material { get; init; } = new();
+            public SpacingDto EdgeSpacing { get; init; } = new();
+        }
+
+        public record DrawingDto
+        {
+            public int Id { get; init; }
+            public string Name { get; init; } = "";
+            public string Customer { get; init; } = "";
+            public ColorDto Color { get; init; } = new();
+            public QuantityDto Quantity { get; init; } = new();
+            public int Priority { get; init; }
+            public ConstraintsDto Constraints { get; init; } = new();
+            public MaterialDto Material { get; init; } = new();
+            public SourceDto Source { get; init; } = new();
+        }
+
+        public record PlateDto
+        {
+            public int Id { get; init; }
+            public SizeDto Size { get; init; } = new();
+            public double Thickness { get; init; }
+            public int Quadrant { get; init; } = 1;
+            public int Quantity { get; init; } = 1;
+            public double PartSpacing { get; init; }
+            public MaterialDto Material { get; init; } = new();
+            public SpacingDto EdgeSpacing { get; init; } = new();
+            public List<PartDto> Parts { get; init; } = new();
+        }
+
+        public record PartDto
+        {
+            public int DrawingId { get; init; }
+            public double X { get; init; }
+            public double Y { get; init; }
+            public double Rotation { get; init; }
+        }
+
+        public record SizeDto
+        {
+            public double Width { get; init; }
+            public double Height { get; init; }
+        }
+
+        public record MaterialDto
+        {
+            public string Name { get; init; } = "";
+            public string Grade { get; init; } = "";
+            public double Density { get; init; }
+        }
+
+        public record SpacingDto
+        {
+            public double Left { get; init; }
+            public double Top { get; init; }
+            public double Right { get; init; }
+            public double Bottom { get; init; }
+        }
+
+        public record ColorDto
+        {
+            public int A { get; init; } = 255;
+            public int R { get; init; }
+            public int G { get; init; }
+            public int B { get; init; }
+        }
+
+        public record QuantityDto
+        {
+            public int Required { get; init; }
+        }
+
+        public record ConstraintsDto
+        {
+            public double StepAngle { get; init; }
+            public double StartAngle { get; init; }
+            public double EndAngle { get; init; }
+            public bool Allow180Equivalent { get; init; }
+        }
+
+        public record SourceDto
+        {
+            public string Path { get; init; } = "";
+            public OffsetDto Offset { get; init; } = new();
+        }
+
+        public record OffsetDto
+        {
+            public double X { get; init; }
+            public double Y { get; init; }
+        }
+    }
+}
+```
+
+- [ ] **Step 2: Build to verify DTOs compile**
+
+Run: `dotnet build OpenNest.IO/OpenNest.IO.csproj`
+Expected: Build succeeded.
+
+- [ ] **Step 3: Commit**
+
+```bash
+git add OpenNest.IO/NestFormat.cs
+git commit -m "feat: add NestFormat DTOs for JSON nest file format v2"
+```
+
+---
+
+## Chunk 2: Rewrite NestWriter
+
+### Task 2: Rewrite NestWriter to use JSON serialization
+
+**Files:**
+- Rewrite: `OpenNest.IO/NestWriter.cs`
+
+The writer keeps the same public API: `NestWriter(Nest nest)` constructor and `bool Write(string file)`. Internally it builds a `NestDto` from the domain model, serializes it to `nest.json`, and writes each drawing's program to `programs/program-N`.
+
+The G-code writing methods (`WriteDrawing`, `GetCodeString`, `GetLayerString`) are preserved exactly — they write program G-code to streams, which is unchanged. The `WritePlate` method and all XML methods (`AddNestInfo`, `AddPlateInfo`, `AddDrawingInfo`) are removed.
+
+- [ ] **Step 1: Rewrite `NestWriter.cs`**
+
+Replace the entire file. Key changes:
+- Remove `using System.Xml`
+- Add `using System.Text.Json`
+- Remove `AddNestInfo()`, `AddPlateInfo()`, `AddDrawingInfo()`, `AddPlates()`, `WritePlate()` methods
+- Add `BuildNestDto()` method that maps domain model → DTOs
+- `Write()` now serializes `NestDto` to `nest.json` and writes programs to `programs/program-N`
+- Keep `WriteDrawing()`, `GetCodeString()`, `GetLayerString()` exactly as-is
+
+```csharp
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.IO.Compression;
+using System.Linq;
+using System.Text;
+using System.Text.Json;
+using OpenNest.CNC;
+using OpenNest.Math;
+using static OpenNest.IO.NestFormat;
+
+namespace OpenNest.IO
+{
+    public sealed class NestWriter
+    {
+        private const int OutputPrecision = 10;
+        private const string CoordinateFormat = "0.##########";
+
+        private readonly Nest nest;
+        private Dictionary<int, Drawing> drawingDict;
+
+        public NestWriter(Nest nest)
+        {
+            this.drawingDict = new Dictionary<int, Drawing>();
+            this.nest = nest;
+        }
+
+        public bool Write(string file)
+        {
+            nest.DateLastModified = DateTime.Now;
+            SetDrawingIds();
+
+            using var fileStream = new FileStream(file, FileMode.Create);
+            using var zipArchive = new ZipArchive(fileStream, ZipArchiveMode.Create);
+
+            WriteNestJson(zipArchive);
+            WritePrograms(zipArchive);
+
+            return true;
+        }
+
+        private void SetDrawingIds()
+        {
+            var id = 1;
+            foreach (var drawing in nest.Drawings)
+            {
+                drawingDict.Add(id, drawing);
+                id++;
+            }
+        }
+
+        private void WriteNestJson(ZipArchive zipArchive)
+        {
+            var dto = BuildNestDto();
+            var json = JsonSerializer.Serialize(dto, JsonOptions);
+
+            var entry = zipArchive.CreateEntry("nest.json");
+            using var stream = entry.Open();
+            using var writer = new StreamWriter(stream, Encoding.UTF8);
+            writer.Write(json);
+        }
+
+        private NestDto BuildNestDto()
+        {
+            return new NestDto
+            {
+                Version = 2,
+                Name = nest.Name ?? "",
+                Units = nest.Units.ToString(),
+                Customer = nest.Customer ?? "",
+                DateCreated = nest.DateCreated.ToString("o"),
+                DateLastModified = nest.DateLastModified.ToString("o"),
+                Notes = nest.Notes ?? "",
+                PlateDefaults = BuildPlateDefaultsDto(),
+                Drawings = BuildDrawingDtos(),
+                Plates = BuildPlateDtos()
+            };
+        }
+
+        private PlateDefaultsDto BuildPlateDefaultsDto()
+        {
+            var pd = nest.PlateDefaults;
+            return new PlateDefaultsDto
+            {
+                Size = new SizeDto { Width = pd.Size.Width, Height = pd.Size.Height },
+                Thickness = pd.Thickness,
+                Quadrant = pd.Quadrant,
+                PartSpacing = pd.PartSpacing,
+                Material = new MaterialDto
+                {
+                    Name = pd.Material.Name ?? "",
+                    Grade = pd.Material.Grade ?? "",
+                    Density = pd.Material.Density
+                },
+                EdgeSpacing = new SpacingDto
+                {
+                    Left = pd.EdgeSpacing.Left,
+                    Top = pd.EdgeSpacing.Top,
+                    Right = pd.EdgeSpacing.Right,
+                    Bottom = pd.EdgeSpacing.Bottom
+                }
+            };
+        }
+
+        private List<DrawingDto> BuildDrawingDtos()
+        {
+            var list = new List<DrawingDto>();
+            foreach (var kvp in drawingDict.OrderBy(k => k.Key))
+            {
+                var d = kvp.Value;
+                list.Add(new DrawingDto
+                {
+                    Id = kvp.Key,
+                    Name = d.Name ?? "",
+                    Customer = d.Customer ?? "",
+                    Color = new ColorDto { A = d.Color.A, R = d.Color.R, G = d.Color.G, B = d.Color.B },
+                    Quantity = new QuantityDto { Required = d.Quantity.Required },
+                    Priority = d.Priority,
+                    Constraints = new ConstraintsDto
+                    {
+                        StepAngle = d.Constraints.StepAngle,
+                        StartAngle = d.Constraints.StartAngle,
+                        EndAngle = d.Constraints.EndAngle,
+                        Allow180Equivalent = d.Constraints.Allow180Equivalent
+                    },
+                    Material = new MaterialDto
+                    {
+                        Name = d.Material.Name ?? "",
+                        Grade = d.Material.Grade ?? "",
+                        Density = d.Material.Density
+                    },
+                    Source = new SourceDto
+                    {
+                        Path = d.Source.Path ?? "",
+                        Offset = new OffsetDto { X = d.Source.Offset.X, Y = d.Source.Offset.Y }
+                    }
+                });
+            }
+            return list;
+        }
+
+        private List<PlateDto> BuildPlateDtos()
+        {
+            var list = new List<PlateDto>();
+            for (var i = 0; i < nest.Plates.Count; i++)
+            {
+                var plate = nest.Plates[i];
+                var parts = new List<PartDto>();
+                foreach (var part in plate.Parts)
+                {
+                    var match = drawingDict.Where(dwg => dwg.Value == part.BaseDrawing).FirstOrDefault();
+                    parts.Add(new PartDto
+                    {
+                        DrawingId = match.Key,
+                        X = part.Location.X,
+                        Y = part.Location.Y,
+                        Rotation = part.Rotation
+                    });
+                }
+
+                list.Add(new PlateDto
+                {
+                    Id = i + 1,
+                    Size = new SizeDto { Width = plate.Size.Width, Height = plate.Size.Height },
+                    Thickness = plate.Thickness,
+                    Quadrant = plate.Quadrant,
+                    Quantity = plate.Quantity,
+                    PartSpacing = plate.PartSpacing,
+                    Material = new MaterialDto
+                    {
+                        Name = plate.Material.Name ?? "",
+                        Grade = plate.Material.Grade ?? "",
+                        Density = plate.Material.Density
+                    },
+                    EdgeSpacing = new SpacingDto
+                    {
+                        Left = plate.EdgeSpacing.Left,
+                        Top = plate.EdgeSpacing.Top,
+                        Right = plate.EdgeSpacing.Right,
+                        Bottom = plate.EdgeSpacing.Bottom
+                    },
+                    Parts = parts
+                });
+            }
+            return list;
+        }
+
+        private void WritePrograms(ZipArchive zipArchive)
+        {
+            foreach (var kvp in drawingDict.OrderBy(k => k.Key))
+            {
+                var name = $"programs/program-{kvp.Key}";
+                var stream = new MemoryStream();
+                WriteDrawing(stream, kvp.Value);
+
+                var entry = zipArchive.CreateEntry(name);
+                using var entryStream = entry.Open();
+                stream.CopyTo(entryStream);
+            }
+        }
+
+        private void WriteDrawing(Stream stream, Drawing drawing)
+        {
+            var program = drawing.Program;
+            var writer = new StreamWriter(stream);
+            writer.AutoFlush = true;
+
+            writer.WriteLine(program.Mode == Mode.Absolute ? "G90" : "G91");
+
+            for (var i = 0; i < drawing.Program.Length; ++i)
+            {
+                var code = drawing.Program[i];
+                writer.WriteLine(GetCodeString(code));
+            }
+
+            stream.Position = 0;
+        }
+
+        private string GetCodeString(ICode code)
+        {
+            switch (code.Type)
+            {
+                case CodeType.ArcMove:
+                    {
+                        var sb = new StringBuilder();
+                        var arcMove = (ArcMove)code;
+
+                        var x = System.Math.Round(arcMove.EndPoint.X, OutputPrecision).ToString(CoordinateFormat);
+                        var y = System.Math.Round(arcMove.EndPoint.Y, OutputPrecision).ToString(CoordinateFormat);
+                        var i = System.Math.Round(arcMove.CenterPoint.X, OutputPrecision).ToString(CoordinateFormat);
+                        var j = System.Math.Round(arcMove.CenterPoint.Y, OutputPrecision).ToString(CoordinateFormat);
+
+                        if (arcMove.Rotation == RotationType.CW)
+                            sb.Append(string.Format("G02X{0}Y{1}I{2}J{3}", x, y, i, j));
+                        else
+                            sb.Append(string.Format("G03X{0}Y{1}I{2}J{3}", x, y, i, j));
+
+                        if (arcMove.Layer != LayerType.Cut)
+                            sb.Append(GetLayerString(arcMove.Layer));
+
+                        return sb.ToString();
+                    }
+
+                case CodeType.Comment:
+                    {
+                        var comment = (Comment)code;
+                        return ":" + comment.Value;
+                    }
+
+                case CodeType.LinearMove:
+                    {
+                        var sb = new StringBuilder();
+                        var linearMove = (LinearMove)code;
+
+                        sb.Append(string.Format("G01X{0}Y{1}",
+                            System.Math.Round(linearMove.EndPoint.X, OutputPrecision).ToString(CoordinateFormat),
+                            System.Math.Round(linearMove.EndPoint.Y, OutputPrecision).ToString(CoordinateFormat)));
+
+                        if (linearMove.Layer != LayerType.Cut)
+                            sb.Append(GetLayerString(linearMove.Layer));
+
+                        return sb.ToString();
+                    }
+
+                case CodeType.RapidMove:
+                    {
+                        var rapidMove = (RapidMove)code;
+
+                        return string.Format("G00X{0}Y{1}",
+                            System.Math.Round(rapidMove.EndPoint.X, OutputPrecision).ToString(CoordinateFormat),
+                            System.Math.Round(rapidMove.EndPoint.Y, OutputPrecision).ToString(CoordinateFormat));
+                    }
+
+                case CodeType.SetFeedrate:
+                    {
+                        var setFeedrate = (Feedrate)code;
+                        return "F" + setFeedrate.Value;
+                    }
+
+                case CodeType.SetKerf:
+                    {
+                        var setKerf = (Kerf)code;
+
+                        switch (setKerf.Value)
+                        {
+                            case KerfType.None: return "G40";
+                            case KerfType.Left: return "G41";
+                            case KerfType.Right: return "G42";
+                        }
+
+                        break;
+                    }
+
+                case CodeType.SubProgramCall:
+                    {
+                        var subProgramCall = (SubProgramCall)code;
+                        break;
+                    }
+            }
+
+            return string.Empty;
+        }
+
+        private string GetLayerString(LayerType layer)
+        {
+            switch (layer)
+            {
+                case LayerType.Display:
+                    return ":DISPLAY";
+
+                case LayerType.Leadin:
+                    return ":LEADIN";
+
+                case LayerType.Leadout:
+                    return ":LEADOUT";
+
+                case LayerType.Scribe:
+                    return ":SCRIBE";
+
+                default:
+                    return string.Empty;
+            }
+        }
+    }
+}
+```
+
+- [ ] **Step 2: Build to verify NestWriter compiles**
+
+Run: `dotnet build OpenNest.sln`
+Expected: Build succeeded.
+
+- [ ] **Step 3: Commit**
+
+```bash
+git add OpenNest.IO/NestWriter.cs
+git commit -m "feat: rewrite NestWriter to use JSON format v2"
+```
+
+---
+
+## Chunk 3: Rewrite NestReader
+
+### Task 3: Rewrite NestReader to use JSON deserialization
+
+**Files:**
+- Rewrite: `OpenNest.IO/NestReader.cs`
+
+The reader keeps the same public API: `NestReader(string file)`, `NestReader(Stream stream)`, and `Nest Read()`. Internally it reads `nest.json`, deserializes to `NestDto`, reads programs from `programs/program-N`, and assembles the domain model.
+
+All XML parsing, plate G-code parsing, dictionary-linking (`LinkProgramsToDrawings`, `LinkPartsToPlates`), and the helper enums/methods are removed.
+
+- [ ] **Step 1: Rewrite `NestReader.cs`**
+
+Replace the entire file:
+
+```csharp
+using System;
+using System.Collections.Generic;
+using System.Drawing;
+using System.IO;
+using System.IO.Compression;
+using System.Linq;
+using System.Text.Json;
+using OpenNest.CNC;
+using OpenNest.Geometry;
+using static OpenNest.IO.NestFormat;
+
+namespace OpenNest.IO
+{
+    public sealed class NestReader
+    {
+        private readonly Stream stream;
+        private readonly ZipArchive zipArchive;
+
+        public NestReader(string file)
+        {
+            stream = new FileStream(file, FileMode.Open, FileAccess.Read);
+            zipArchive = new ZipArchive(stream, ZipArchiveMode.Read);
+        }
+
+        public NestReader(Stream stream)
+        {
+            this.stream = stream;
+            zipArchive = new ZipArchive(stream, ZipArchiveMode.Read);
+        }
+
+        public Nest Read()
+        {
+            var nestJson = ReadEntry("nest.json");
+            var dto = JsonSerializer.Deserialize<NestDto>(nestJson, JsonOptions);
+
+            var programs = ReadPrograms(dto.Drawings.Count);
+            var drawingMap = BuildDrawings(dto, programs);
+            var nest = BuildNest(dto, drawingMap);
+
+            zipArchive.Dispose();
+            stream.Close();
+
+            return nest;
+        }
+
+        private string ReadEntry(string name)
+        {
+            var entry = zipArchive.GetEntry(name)
+                ?? throw new InvalidDataException($"Nest file is missing required entry '{name}'.");
+            using var entryStream = entry.Open();
+            using var reader = new StreamReader(entryStream);
+            return reader.ReadToEnd();
+        }
+
+        private Dictionary<int, Program> ReadPrograms(int count)
+        {
+            var programs = new Dictionary<int, Program>();
+            for (var i = 1; i <= count; i++)
+            {
+                var entry = zipArchive.GetEntry($"programs/program-{i}");
+                if (entry == null) continue;
+
+                using var entryStream = entry.Open();
+                var memStream = new MemoryStream();
+                entryStream.CopyTo(memStream);
+                memStream.Position = 0;
+
+                var reader = new ProgramReader(memStream);
+                programs[i] = reader.Read();
+            }
+            return programs;
+        }
+
+        private Dictionary<int, Drawing> BuildDrawings(NestDto dto, Dictionary<int, Program> programs)
+        {
+            var map = new Dictionary<int, Drawing>();
+            foreach (var d in dto.Drawings)
+            {
+                var drawing = new Drawing(d.Name);
+                drawing.Customer = d.Customer;
+                drawing.Color = Color.FromArgb(d.Color.A, d.Color.R, d.Color.G, d.Color.B);
+                drawing.Quantity.Required = d.Quantity.Required;
+                drawing.Priority = d.Priority;
+                drawing.Constraints.StepAngle = d.Constraints.StepAngle;
+                drawing.Constraints.StartAngle = d.Constraints.StartAngle;
+                drawing.Constraints.EndAngle = d.Constraints.EndAngle;
+                drawing.Constraints.Allow180Equivalent = d.Constraints.Allow180Equivalent;
+                drawing.Material = new Material(d.Material.Name, d.Material.Grade, d.Material.Density);
+                drawing.Source.Path = d.Source.Path;
+                drawing.Source.Offset = new Vector(d.Source.Offset.X, d.Source.Offset.Y);
+
+                if (programs.TryGetValue(d.Id, out var pgm))
+                    drawing.Program = pgm;
+
+                map[d.Id] = drawing;
+            }
+            return map;
+        }
+
+        private Nest BuildNest(NestDto dto, Dictionary<int, Drawing> drawingMap)
+        {
+            var nest = new Nest();
+            nest.Name = dto.Name;
+
+            Units units;
+            if (Enum.TryParse(dto.Units, true, out units))
+                nest.Units = units;
+
+            nest.Customer = dto.Customer;
+            nest.DateCreated = DateTime.Parse(dto.DateCreated);
+            nest.DateLastModified = DateTime.Parse(dto.DateLastModified);
+            nest.Notes = dto.Notes;
+
+            // Plate defaults
+            var pd = dto.PlateDefaults;
+            nest.PlateDefaults.Size = new Size(pd.Size.Width, pd.Size.Height);
+            nest.PlateDefaults.Thickness = pd.Thickness;
+            nest.PlateDefaults.Quadrant = pd.Quadrant;
+            nest.PlateDefaults.PartSpacing = pd.PartSpacing;
+            nest.PlateDefaults.Material = new Material(pd.Material.Name, pd.Material.Grade, pd.Material.Density);
+            nest.PlateDefaults.EdgeSpacing = new Spacing(pd.EdgeSpacing.Left, pd.EdgeSpacing.Bottom, pd.EdgeSpacing.Right, pd.EdgeSpacing.Top);
+
+            // Drawings
+            foreach (var d in drawingMap.OrderBy(k => k.Key))
+                nest.Drawings.Add(d.Value);
+
+            // Plates
+            foreach (var p in dto.Plates.OrderBy(p => p.Id))
+            {
+                var plate = new Plate();
+                plate.Size = new Size(p.Size.Width, p.Size.Height);
+                plate.Thickness = p.Thickness;
+                plate.Quadrant = p.Quadrant;
+                plate.Quantity = p.Quantity;
+                plate.PartSpacing = p.PartSpacing;
+                plate.Material = new Material(p.Material.Name, p.Material.Grade, p.Material.Density);
+                plate.EdgeSpacing = new Spacing(p.EdgeSpacing.Left, p.EdgeSpacing.Bottom, p.EdgeSpacing.Right, p.EdgeSpacing.Top);
+
+                foreach (var partDto in p.Parts)
+                {
+                    if (!drawingMap.TryGetValue(partDto.DrawingId, out var dwg))
+                        continue;
+
+                    var part = new Part(dwg);
+                    part.Rotate(partDto.Rotation);
+                    part.Offset(new Vector(partDto.X, partDto.Y));
+                    plate.Parts.Add(part);
+                }
+
+                nest.Plates.Add(plate);
+            }
+
+            return nest;
+        }
+    }
+}
+```
+
+- [ ] **Step 2: Build to verify NestReader compiles**
+
+Run: `dotnet build OpenNest.sln`
+Expected: Build succeeded.
+
+- [ ] **Step 3: Commit**
+
+```bash
+git add OpenNest.IO/NestReader.cs
+git commit -m "feat: rewrite NestReader to use JSON format v2"
+```
+
+---
+
+## Chunk 4: Smoke Test
+
+### Task 4: Manual smoke test via OpenNest.Console
+
+**Files:** None modified — this is a verification step.
+
+Use the `OpenNest.Console` project (or the MCP server) to verify round-trip: create a nest, save it, reload it, confirm data is intact.
+
+- [ ] **Step 1: Build the full solution**
+
+Run: `dotnet build OpenNest.sln`
+Expected: Build succeeded with no errors.
+
+- [ ] **Step 2: Round-trip test via MCP tools**
+
+Use the OpenNest MCP tools to:
+1. Create a drawing (e.g. a rectangle via `create_drawing`)
+2. Create a plate via `create_plate`
+3. Fill the plate via `fill_plate`
+4. Save the nest via the console app or verify `get_plate_info` shows parts
+5. If a nest file exists on disk, load it with `load_nest` and verify `get_plate_info` returns the same data
+
+- [ ] **Step 3: Inspect the ZIP contents**
+
+Unzip a saved nest file and verify:
+- `nest.json` exists with correct structure
+- `programs/program-1` (etc.) exist with G-code content
+- No `info`, `drawing-info`, `plate-info`, or `plate-NNN` files exist
+
+- [ ] **Step 4: Commit any fixes**
+
+If any issues were found and fixed, commit them:
+
+```bash
+git add -u
+git commit -m "fix: address issues found during nest format v2 smoke test"
+```

docs/superpowers/specs/2026-03-12-contour-reindexing-design.md

@@ -0,0 +1,134 @@
+# Contour Re-Indexing Design
+
+## Overview
+
+Add entity-splitting primitives and a `Shape.ReindexAt` method so that a closed contour can be reordered to start (and end) at an arbitrary point. Then wire this into `ContourCuttingStrategy.Apply()` to replace the `NotImplementedException` stubs.
+
+All geometry additions live on existing classes in `OpenNest.Geometry`. The strategy wiring is a change to the existing `ContourCuttingStrategy` in `OpenNest.CNC.CuttingStrategy`.
+
+## Entity Splitting Primitives
+
+### Line.SplitAt(Vector point)
+
+```csharp
+public (Line first, Line second) SplitAt(Vector point)
+```
+
+- Returns two lines: `StartPoint → point` and `point → EndPoint`.
+- If the point is at `StartPoint` (within `Tolerance.Epsilon` distance), `first` is null.
+- If the point is at `EndPoint` (within `Tolerance.Epsilon` distance), `second` is null.
+- The point is assumed to lie on the line (caller is responsible — it comes from `ClosestPointTo`).
+
+### Arc.SplitAt(Vector point)
+
+```csharp
+public (Arc first, Arc second) SplitAt(Vector point)
+```
+
+- Computes `splitAngle = Center.AngleTo(point)`, normalized via `Angle.NormalizeRad`.
+- First arc: same center, radius, direction — `StartAngle → splitAngle`.
+- Second arc: same center, radius, direction — `splitAngle → EndAngle`.
+- **Endpoint tolerance**: compare `point.DistanceTo(arc.StartPoint())` and `point.DistanceTo(arc.EndPoint())` rather than comparing angles directly. This avoids wrap-around issues at the 0/2π boundary.
+- If the point is at `StartPoint()` (within `Tolerance.Epsilon` distance), `first` is null.
+- If the point is at `EndPoint()` (within `Tolerance.Epsilon` distance), `second` is null.
+
+### Circle — no conversion needed
+
+Circles are kept as-is in `ReindexAt`. The `ConvertShapeToMoves` method handles circles directly by emitting an `ArcMove` from the start point back to itself (a full circle), matching the existing `ConvertGeometry.AddCircle` pattern. This avoids the problem of constructing a "full-sweep arc" where `StartAngle == EndAngle` would produce zero sweep.
+
+## Shape.ReindexAt
+
+```csharp
+public Shape ReindexAt(Vector point, Entity entity)
+```
+
+- `point`: the start/end point for the reindexed contour (from `ClosestPointTo`).
+- `entity`: the entity containing `point` (from `ClosestPointTo`'s `out` parameter).
+- Returns a **new** Shape (does not modify the original). The new shape shares entity references with the original for unsplit entities — callers must not mutate either.
+- Throws `ArgumentException` if `entity` is not found in `Entities`.
+
+### Algorithm
+
+1. If `entity` is a `Circle`:
+   - Return a new Shape with that single `Circle` entity and `point` stored for `ConvertShapeToMoves` to use as the start point.
+
+2. Find the index `i` of `entity` in `Entities`. Throw `ArgumentException` if not found.
+
+3. Split the entity at `point`:
+   - `Line` → `line.SplitAt(point)` → `(firstHalf, secondHalf)`
+   - `Arc` → `arc.SplitAt(point)` → `(firstHalf, secondHalf)`
+
+4. Build the new entity list (skip null entries):
+   - `secondHalf` (if not null)
+   - `Entities[i+1]`, `Entities[i+2]`, ..., `Entities[count-1]` (after the split)
+   - `Entities[0]`, `Entities[1]`, ..., `Entities[i-1]` (before the split, wrapping around)
+   - `firstHalf` (if not null)
+
+5. Return a new Shape with this entity list.
+
+### Edge Cases
+
+- **Point lands on entity boundary** (start/end of an entity): one half of the split is null. The reordering still works — it just starts from the next full entity.
+- **Single-entity shape that is an Arc**: split produces two arcs, reorder is just `[secondHalf, firstHalf]`.
+- **Single-entity Circle**: handled by step 1 — kept as Circle, converted to a full-circle ArcMove in `ConvertShapeToMoves`.
+
+## Wiring into ContourCuttingStrategy
+
+### Entity-to-ICode Conversion
+
+Add a private method to `ContourCuttingStrategy`:
+
+```csharp
+private List<ICode> ConvertShapeToMoves(Shape shape, Vector startPoint)
+```
+
+The `startPoint` parameter is needed for the Circle case (to know where the full-circle ArcMove starts).
+
+Iterates `shape.Entities` and converts each to cutting moves using **absolute coordinates** (consistent with `ConvertGeometry`):
+- `Line` → `LinearMove(line.EndPoint)`
+- `Arc` → `ArcMove(arc.EndPoint(), arc.Center, arc.IsReversed ? RotationType.CW : RotationType.CCW)`
+- `Circle` → `ArcMove(startPoint, circle.Center, circle.Rotation)` — full circle from start point back to itself, matching `ConvertGeometry.AddCircle`
+- Any other entity type → throw `InvalidOperationException`
+
+No `RapidMove` between entities — they are contiguous in a reindexed shape. The lead-in already positions the head at the shape's start point.
+
+### Replace NotImplementedException
+
+In `ContourCuttingStrategy.Apply()`, replace the two `throw new NotImplementedException(...)` blocks:
+
+**Cutout loop** (uses `cutout` shape variable):
+```csharp
+var reindexed = cutout.ReindexAt(closestPt, entity);
+result.Codes.AddRange(ConvertShapeToMoves(reindexed, closestPt));
+```
+
+**Perimeter block** (uses `profile.Perimeter`):
+```csharp
+var reindexed = profile.Perimeter.ReindexAt(perimeterPt, perimeterEntity);
+result.Codes.AddRange(ConvertShapeToMoves(reindexed, perimeterPt));
+```
+
+The full sequence for each contour becomes:
+1. Lead-in codes (rapid to pierce point, cutting moves to contour start)
+2. Contour body (reindexed entity moves from `ConvertShapeToMoves`)
+3. Lead-out codes (overcut moves away from contour)
+
+### MicrotabLeadOut Handling
+
+When the lead-out is `MicrotabLeadOut`, the last cutting move must be trimmed by `GapSize`. This is a separate concern from re-indexing — stub it with a TODO comment for now. The trimming logic will shorten the last `LinearMove` or `ArcMove` in the contour body.
+
+## Files Modified
+
+| File | Change |
+|------|--------|
+| `OpenNest.Core/Geometry/Line.cs` | Add `SplitAt(Vector)` method |
+| `OpenNest.Core/Geometry/Arc.cs` | Add `SplitAt(Vector)` method |
+| `OpenNest.Core/Geometry/Shape.cs` | Add `ReindexAt(Vector, Entity)` method |
+| `OpenNest.Core/CNC/CuttingStrategy/ContourCuttingStrategy.cs` | Add `ConvertShapeToMoves`, replace `NotImplementedException` blocks |
+
+## Out of Scope
+
+- **MicrotabLeadOut trimming** (trim last move by gap size — stubbed with TODO)
+- **Tab insertion** (inserting tab codes mid-contour — already stubbed)
+- **Lead-in editor UI** (interactive start point selection — separate feature)
+- **Contour re-indexing for open shapes** (only closed contours supported)

docs/superpowers/specs/2026-03-12-cutting-strategy-design.md

@@ -0,0 +1,420 @@
+# CNC Cutting Strategy Design
+
+## Overview
+
+Add lead-in, lead-out, and tab classes to `OpenNest.Core` that generate `ICode` instructions for CNC cutting approach/exit geometry. The strategy runs at nest-time — `ContourCuttingStrategy.Apply()` produces a new `Program` with lead-ins, lead-outs, start points, and contour ordering baked in. This modified program is what gets saved to the nest file and later fed to the post-processor for machine-specific G-code translation. The original `Drawing.Program` stays untouched; the strategy output lives on the `Part`.
+
+All new code lives in `OpenNest.Core/CNC/CuttingStrategy/`.
+
+## File Structure
+
+```
+OpenNest.Core/CNC/CuttingStrategy/
+├── LeadIns/
+│   ├── LeadIn.cs
+│   ├── NoLeadIn.cs
+│   ├── LineLeadIn.cs
+│   ├── LineArcLeadIn.cs
+│   ├── ArcLeadIn.cs
+│   ├── LineLineLeadIn.cs
+│   └── CleanHoleLeadIn.cs
+├── LeadOuts/
+│   ├── LeadOut.cs
+│   ├── NoLeadOut.cs
+│   ├── LineLeadOut.cs
+│   ├── ArcLeadOut.cs
+│   └── MicrotabLeadOut.cs
+├── Tabs/
+│   ├── Tab.cs
+│   ├── NormalTab.cs
+│   ├── BreakerTab.cs
+│   └── MachineTab.cs
+├── ContourType.cs
+├── CuttingParameters.cs
+├── ContourCuttingStrategy.cs
+├── SequenceParameters.cs
+└── AssignmentParameters.cs
+```
+
+## Namespace
+
+All classes use `namespace OpenNest.CNC.CuttingStrategy`.
+
+## Type Mappings from Original Spec
+
+The original spec used placeholder names. These are the correct codebase types:
+
+| Spec type | Actual type | Notes |
+|-----------|------------|-------|
+| `PointD` | `Vector` | `OpenNest.Geometry.Vector` — struct with `X`, `Y` fields |
+| `CircularMove` | `ArcMove` | Constructor: `ArcMove(Vector endPoint, Vector centerPoint, RotationType rotation)` |
+| `CircularDirection` | `RotationType` | Enum with `CW`, `CCW` |
+| `value.ToRadians()` | `Angle.ToRadians(value)` | Static method on `OpenNest.Math.Angle` |
+| `new Program(codes)` | Build manually | Create `Program()`, add to `.Codes` list |
+
+## LeadIn Hierarchy
+
+### Abstract Base: `LeadIn`
+
+```csharp
+public abstract class LeadIn
+{
+    public abstract List<ICode> Generate(Vector contourStartPoint, double contourNormalAngle,
+        RotationType winding = RotationType.CW);
+    public abstract Vector GetPiercePoint(Vector contourStartPoint, double contourNormalAngle);
+}
+```
+
+- `contourStartPoint`: where the contour cut begins (first point of the part profile).
+- `contourNormalAngle`: normal angle (radians) at the contour start point, pointing **away from the part material** (outward from perimeter, into scrap for cutouts).
+- `winding`: contour winding direction — arc-based lead-ins use this for their `ArcMove` rotation.
+- `Generate` returns ICode instructions starting with a `RapidMove` to the pierce point, followed by cutting moves to reach the contour start.
+- `GetPiercePoint` computes where the head rapids to before firing — useful for visualization and collision detection.
+
+### NoLeadIn (Type 0)
+
+Pierce directly on the contour start point. Returns a single `RapidMove(contourStartPoint)`.
+
+### LineLeadIn (Type 1)
+
+Straight line approach.
+
+Properties:
+- `Length` (double): distance from pierce point to contour start (inches)
+- `ApproachAngle` (double): approach angle in degrees relative to contour tangent. 90 = perpendicular, 135 = acute angle (common for plasma). Default: 90.
+
+Pierce point offset: `contourStartPoint + Length` along `contourNormalAngle + Angle.ToRadians(ApproachAngle)`.
+
+Generates: `RapidMove(piercePoint)` → `LinearMove(contourStartPoint)`.
+
+> **Note:** Properties are named `ApproachAngle` (not `Angle`) to avoid shadowing the `OpenNest.Math.Angle` static class. This applies to all lead-in/lead-out/tab classes.
+
+### LineArcLeadIn (Type 2)
+
+Line followed by tangential arc meeting the contour. Most common for plasma.
+
+Properties:
+- `LineLength` (double): straight approach segment length
+- `ApproachAngle` (double): line angle relative to contour. Default: 135.
+- `ArcRadius` (double): radius of tangential arc
+
+Geometry: Pierce → [Line] → Arc start → [Arc] → Contour start. Arc center is at `contourStartPoint + ArcRadius` along normal. Arc rotation direction matches contour winding (CW for CW contours, CCW for CCW).
+
+Generates: `RapidMove(piercePoint)` → `LinearMove(arcStart)` → `ArcMove(contourStartPoint, arcCenter, rotation)`.
+
+### ArcLeadIn (Type 3)
+
+Pure arc approach, no straight line segment.
+
+Properties:
+- `Radius` (double): arc radius
+
+Pierce point is diametrically opposite the contour start on the arc circle. Arc center at `contourStartPoint + Radius` along normal.
+
+Arc rotation direction matches contour winding.
+
+Generates: `RapidMove(piercePoint)` → `ArcMove(contourStartPoint, arcCenter, rotation)`.
+
+### LineLineLeadIn (Type 5)
+
+Two-segment straight line approach.
+
+Properties:
+- `Length1` (double): first segment length
+- `ApproachAngle1` (double): first segment angle. Default: 90.
+- `Length2` (double): second segment length
+- `ApproachAngle2` (double): direction change. Default: 90.
+
+Generates: `RapidMove(piercePoint)` → `LinearMove(midPoint)` → `LinearMove(contourStartPoint)`.
+
+### CleanHoleLeadIn
+
+Specialized for precision circular holes. Same geometry as `LineArcLeadIn` but with hard-coded 135° angle and a `Kerf` property. The overcut (cutting past start to close the hole) is handled at the lead-out, not here.
+
+Properties:
+- `LineLength` (double)
+- `ArcRadius` (double)
+- `Kerf` (double)
+
+## LeadOut Hierarchy
+
+### Abstract Base: `LeadOut`
+
+```csharp
+public abstract class LeadOut
+{
+    public abstract List<ICode> Generate(Vector contourEndPoint, double contourNormalAngle,
+        RotationType winding = RotationType.CW);
+}
+```
+
+- `contourEndPoint`: where the contour cut ends. For closed contours, same as start.
+- Returns ICode instructions appended after the contour's last cut point.
+
+### NoLeadOut (Type 0)
+
+Returns empty list. Cut ends exactly at contour end.
+
+### LineLeadOut (Type 1)
+
+Straight line overcut past contour end.
+
+Properties:
+- `Length` (double): overcut distance
+- `ApproachAngle` (double): direction relative to contour tangent. Default: 90.
+
+Generates: `LinearMove(endPoint)` where endPoint is offset from contourEndPoint.
+
+### ArcLeadOut (Type 3)
+
+Arc overcut curving away from the part.
+
+Properties:
+- `Radius` (double)
+
+Arc center at `contourEndPoint + Radius` along normal. End point is a quarter turn away. Arc rotation direction matches contour winding.
+
+Generates: `ArcMove(endPoint, arcCenter, rotation)`.
+
+### MicrotabLeadOut (Type 4)
+
+Stops short of contour end, leaving an uncut bridge. Laser only.
+
+Properties:
+- `GapSize` (double): uncut material length. Default: 0.03".
+
+Does NOT add instructions — returns empty list. The `ContourCuttingStrategy` detects this type and trims the last cutting move by `GapSize` instead.
+
+## Tab Hierarchy
+
+Tabs are mid-contour features that temporarily lift the beam to leave bridges holding the part in place.
+
+### Abstract Base: `Tab`
+
+```csharp
+public abstract class Tab
+{
+    public double Size { get; set; } = 0.03;
+    public LeadIn TabLeadIn { get; set; }
+    public LeadOut TabLeadOut { get; set; }
+
+    public abstract List<ICode> Generate(
+        Vector tabStartPoint, Vector tabEndPoint, double contourNormalAngle);
+}
+```
+
+### NormalTab
+
+Standard tab: cut up to tab start, lift/rapid over gap, resume cutting.
+
+Additional properties:
+- `CutoutMinWidth`, `CutoutMinHeight` (double): minimum cutout size to receive this tab
+- `CutoutMaxWidth`, `CutoutMaxHeight` (double): maximum cutout size to receive this tab
+- `AppliesToCutout(double width, double height)` method for size filtering
+
+Generates: TabLeadOut codes → `RapidMove(tabEndPoint)` → TabLeadIn codes.
+
+### BreakerTab
+
+Like NormalTab but adds a scoring cut into the part at the tab location to make snapping easier.
+
+Additional properties:
+- `BreakerDepth` (double): how far the score cuts into the part
+- `BreakerLeadInLength` (double)
+- `BreakerAngle` (double)
+
+Generates: TabLeadOut codes → `LinearMove(scoreEnd)` → `RapidMove(tabEndPoint)` → TabLeadIn codes.
+
+### MachineTab
+
+Tab behavior configured at the CNC controller level. OpenNest just signals the controller.
+
+Additional properties:
+- `MachineTabId` (int): passed to post-processor for M-code translation
+
+Returns a placeholder `RapidMove(tabEndPoint)` — the post-processor plugin replaces this with machine-specific commands.
+
+## CuttingParameters
+
+One instance per material/machine combination. Ties everything together.
+
+```csharp
+public class CuttingParameters
+{
+    public int Id { get; set; }
+
+    // Material/Machine identification
+    public string MachineName { get; set; }
+    public string MaterialName { get; set; }
+    public string Grade { get; set; }
+    public double Thickness { get; set; }
+
+    // Kerf and spacing
+    public double Kerf { get; set; }
+    public double PartSpacing { get; set; }
+
+    // External contour lead-in/out
+    public LeadIn ExternalLeadIn { get; set; } = new NoLeadIn();
+    public LeadOut ExternalLeadOut { get; set; } = new NoLeadOut();
+
+    // Internal contour lead-in/out
+    public LeadIn InternalLeadIn { get; set; } = new LineLeadIn { Length = 0.125, Angle = 90 };
+    public LeadOut InternalLeadOut { get; set; } = new NoLeadOut();
+
+    // Arc/circle specific (overrides internal for circular features)
+    public LeadIn ArcCircleLeadIn { get; set; } = new NoLeadIn();
+    public LeadOut ArcCircleLeadOut { get; set; } = new NoLeadOut();
+
+    // Tab configuration
+    public Tab TabConfig { get; set; }
+    public bool TabsEnabled { get; set; } = false;
+
+    // Sequencing and assignment
+    public SequenceParameters Sequencing { get; set; } = new SequenceParameters();
+    public AssignmentParameters Assignment { get; set; } = new AssignmentParameters();
+}
+```
+
+## SequenceParameters and AssignmentParameters
+
+```csharp
+// Values match PEP Technology's numbering scheme (value 6 intentionally skipped)
+public enum SequenceMethod
+{
+    RightSide = 1, LeastCode = 2, Advanced = 3,
+    BottomSide = 4, EdgeStart = 5, LeftSide = 7, RightSideAlt = 8
+}
+
+public class SequenceParameters
+{
+    public SequenceMethod Method { get; set; } = SequenceMethod.Advanced;
+    public double SmallCutoutWidth { get; set; } = 1.5;
+    public double SmallCutoutHeight { get; set; } = 1.5;
+    public double MediumCutoutWidth { get; set; } = 8.0;
+    public double MediumCutoutHeight { get; set; } = 8.0;
+    public double DistanceMediumSmall { get; set; }
+    public bool AlternateRowsColumns { get; set; } = true;
+    public bool AlternateCutoutsWithinRowColumn { get; set; } = true;
+    public double MinDistanceBetweenRowsColumns { get; set; } = 0.25;
+}
+
+public class AssignmentParameters
+{
+    public SequenceMethod Method { get; set; } = SequenceMethod.Advanced;
+    public string Preference { get; set; } = "ILAT";
+    public double MinGeometryLength { get; set; } = 0.01;
+}
+```
+
+## ContourCuttingStrategy
+
+The orchestrator. Uses `ShapeProfile` to decompose a part into perimeter + cutouts, then sequences and applies cutting parameters using nearest-neighbor chaining from an exit point.
+
+### Exit Point from Plate Quadrant
+
+The exit point is the **opposite corner** of the plate from the quadrant origin. This is where the head ends up after traversing the plate, and is the starting point for backwards nearest-neighbor sequencing.
+
+| Quadrant | Origin | Exit Point |
+|----------|--------|------------|
+| 1 | TopRight | BottomLeft (0, 0) |
+| 2 | TopLeft | BottomRight (width, 0) |
+| 3 | BottomLeft | TopRight (width, length) |
+| 4 | BottomRight | TopLeft (0, length) |
+
+The exit point is derived from `Plate.Quadrant` and `Plate.Size` — not passed in manually.
+
+### Approach
+
+Instead of requiring `Program.GetStartPoint()` / `GetNormalAtStart()` (which don't exist), the strategy:
+
+1. Computes the **exit point** from the plate's quadrant and size
+2. Converts the program to geometry via `Program.ToGeometry()`
+3. Builds a `ShapeProfile` from the geometry — gives `Perimeter` (Shape) and `Cutouts` (List&lt;Shape&gt;)
+4. Uses `Shape.ClosestPointTo(point, out Entity entity)` to find lead-in points and the entity for normal computation
+5. Chains cutouts by nearest-neighbor distance from the perimeter closest point
+6. Reverses the chain → cut order is cutouts first (nearest-last), perimeter last
+
+### Contour Re-Indexing
+
+After `ClosestPointTo` finds the lead-in point on a shape, the shape's entity list must be reordered so that cutting starts at that point. This means:
+
+1. Find which entity in `Shape.Entities` contains the closest point
+2. Split that entity at the closest point into two segments
+3. Reorder: second half of split entity → remaining entities in order → first half of split entity
+4. The contour now starts and ends at the lead-in point (for closed contours)
+
+This produces the `List<ICode>` for the contour body that goes between the lead-in and lead-out codes.
+
+### ContourType Detection
+
+- `ShapeProfile.Perimeter` → `ContourType.External`
+- Each cutout in `ShapeProfile.Cutouts`:
+  - If single entity and entity is `Circle` → `ContourType.ArcCircle`
+  - Otherwise → `ContourType.Internal`
+
+### Normal Angle Computation
+
+Derived from the `out Entity` returned by `ClosestPointTo`:
+
+- **Line**: normal is perpendicular to line direction. Use the line's tangent angle, then add π/2 for the normal pointing away from the part interior.
+- **Arc/Circle**: normal is radial direction from arc center to the closest point: `closestPoint.AngleFrom(arc.Center)`.
+
+Normal direction convention: always points **away from the part material** (outward from perimeter, inward toward scrap for cutouts). The lead-in approaches from this direction.
+
+### Arc Rotation Direction
+
+Lead-in/lead-out arcs must match the **contour winding direction**, not be hardcoded CW. Determine winding from the shape's entity traversal order. Pass the appropriate `RotationType` to `ArcMove`.
+
+### Method Signature
+
+```csharp
+public class ContourCuttingStrategy
+{
+    public CuttingParameters Parameters { get; set; }
+
+    /// <summary>
+    /// Apply cutting strategy to a part's program.
+    /// </summary>
+    /// <param name="partProgram">Original part program (unmodified).</param>
+    /// <param name="plate">Plate for quadrant/size to compute exit point.</param>
+    /// <returns>New Program with lead-ins, lead-outs, and tabs applied. Cutouts first, perimeter last.</returns>
+    public Program Apply(Program partProgram, Plate plate)
+    {
+        // 1. Compute exit point from plate quadrant + size
+        // 2. Convert to geometry, build ShapeProfile
+        // 3. Find closest point on perimeter from exitPoint
+        // 4. Chain cutouts by nearest-neighbor from perimeter point
+        // 5. Reverse chain → cut order
+        // 6. For each contour:
+        //    a. Re-index shape entities to start at closest point
+        //    b. Detect ContourType
+        //    c. Compute normal angle from entity
+        //    d. Select lead-in/out from CuttingParameters by ContourType
+        //    e. Generate lead-in codes + contour body + lead-out codes
+        // 7. Handle MicrotabLeadOut by trimming last segment
+        // 8. Assemble and return new Program
+    }
+}
+```
+
+### ContourType Enum
+
+```csharp
+public enum ContourType
+{
+    External,
+    Internal,
+    ArcCircle
+}
+```
+
+## Integration Point
+
+`ContourCuttingStrategy.Apply()` runs at nest-time (when parts are placed or cutting parameters are assigned), not at post-processing time. The output `Program` — with lead-ins, lead-outs, start points, and contour ordering — is stored on the `Part` and saved through the normal `NestWriter` path. The post-processor receives this already-complete program and only translates it to machine-specific G-code.
+
+## Out of Scope (Deferred)
+
+- **Serialization** of CuttingParameters (JSON/XML discriminators)
+- **UI integration** (parameter editor forms in WinForms app)
+- **Part.CutProgram property** (storing the strategy-applied program on `Part`, separate from `Drawing.Program`)
+- **Tab insertion logic** (`InsertTabs` / `TrimLastSegment` — stubbed with `NotImplementedException`)

docs/superpowers/specs/2026-03-12-nest-file-format-v2-design.md

@@ -0,0 +1,134 @@
+# Nest File Format v2 Design
+
+## Problem
+
+The current nest file format stores metadata across three separate XML files (`info`, `drawing-info`, `plate-info`) plus per-plate G-code files for part placements inside a ZIP archive. This results in ~400 lines of hand-written XML read/write code, fragile dictionary-linking to reconnect drawings/plates by ID after parsing, and the overhead of running the full G-code parser just to extract part positions.
+
+## Design
+
+### File Structure
+
+The nest file remains a ZIP archive. Contents:
+
+```
+nest.json
+programs/
+  program-1
+  program-2
+  ...
+```
+
+- **`nest.json`** — single JSON file containing all metadata and part placements.
+- **`programs/program-N`** — G-code text for each drawing's CNC program (1-indexed, no zero-padding). Previously stored at the archive root as `program-NNN` (zero-padded). Parsed by `ProgramReader`, written by existing G-code serialization logic. Format unchanged.
+
+Plate G-code files (`plate-NNN`) are removed. Part placements are stored inline in `nest.json`.
+
+### JSON Schema
+
+```json
+{
+  "version": 2,
+  "name": "string",
+  "units": "Inches | Millimeters",
+  "customer": "string",
+  "dateCreated": "2026-03-12T10:30:00",
+  "dateLastModified": "2026-03-12T14:00:00",
+  "notes": "string (plain JSON, no URI-escaping)",
+  "plateDefaults": {
+    "size": { "width": 0.0, "height": 0.0 },
+    "thickness": 0.0,
+    "quadrant": 1,
+    "partSpacing": 0.0,
+    "material": { "name": "string", "grade": "string", "density": 0.0 },
+    "edgeSpacing": { "left": 0.0, "top": 0.0, "right": 0.0, "bottom": 0.0 }
+  },
+  "drawings": [
+    {
+      "id": 1,
+      "name": "string",
+      "customer": "string",
+      "color": { "a": 255, "r": 0, "g": 0, "b": 0 },
+      "quantity": { "required": 0 },
+      "priority": 0,
+      "constraints": {
+        "stepAngle": 0.0,
+        "startAngle": 0.0,
+        "endAngle": 0.0,
+        "allow180Equivalent": false
+      },
+      "material": { "name": "string", "grade": "string", "density": 0.0 },
+      "source": {
+        "path": "string",
+        "offset": { "x": 0.0, "y": 0.0 }
+      }
+    }
+  ],
+  "plates": [
+    {
+      "id": 1,
+      "size": { "width": 0.0, "height": 0.0 },
+      "thickness": 0.0,
+      "quadrant": 1,
+      "quantity": 1,
+      "partSpacing": 0.0,
+      "material": { "name": "string", "grade": "string", "density": 0.0 },
+      "edgeSpacing": { "left": 0.0, "top": 0.0, "right": 0.0, "bottom": 0.0 },
+      "parts": [
+        { "drawingId": 1, "x": 0.0, "y": 0.0, "rotation": 0.0 }
+      ]
+    }
+  ]
+}
+```
+
+Key details:
+- **Version**: `"version": 2` at the top level for future format migration.
+- Drawing `id` values are 1-indexed, matching `programs/program-N` filenames.
+- Part `rotation` is stored in **radians** (matches internal domain model, no conversion needed).
+- Part `drawingId` references the drawing's `id` in the `drawings` array.
+- **Dates**: local time, serialized via `DateTime.ToString("o")` (ISO 8601 round-trip format with timezone offset).
+- **Notes**: stored as plain JSON strings. The v1 URI-escaping (`Uri.EscapeDataString`) is not needed since JSON handles special characters natively.
+- `quantity.required` is the only quantity persisted; `nested` is computed at load time from part placements.
+- **Units**: enum values match the domain model: `Inches` or `Millimeters`.
+- **Size**: uses `width`/`height` matching the `OpenNest.Geometry.Size` struct.
+- **Drawing.Priority** and **Drawing.Constraints** (stepAngle, startAngle, endAngle, allow180Equivalent) are now persisted (v1 omitted these).
+- **Empty collections**: `drawings` and `plates` arrays are always present (may be empty `[]`). The `programs/` folder is empty when there are no drawings.
+
+### Serialization Approach
+
+Use `System.Text.Json` with small DTO (Data Transfer Object) classes for serialization. The DTOs map between the domain model and the JSON structure, keeping serialization concerns out of the domain classes.
+
+### What Changes
+
+| File | Change |
+|------|--------|
+| `NestWriter.cs` | Replace all XML writing and plate G-code writing with JSON serialization. Programs written to `programs/` folder. |
+| `NestReader.cs` | Replace all XML parsing, plate G-code parsing, and dictionary-linking with JSON deserialization. Programs read from `programs/` folder. |
+
+### What Stays the Same
+
+| File | Reason |
+|------|--------|
+| `ProgramReader.cs` | G-code parsing for CNC programs is unchanged. |
+| `NestWriter` G-code writing (`WriteDrawing`, `GetCodeString`) | G-code serialization for programs is unchanged. |
+| `DxfImporter.cs`, `DxfExporter.cs`, `Extensions.cs` | Unrelated to nest file format. |
+| Domain model classes | No changes needed. |
+
+### Public API
+
+The public API is unchanged:
+- `NestReader(string file)` and `NestReader(Stream stream)` constructors preserved.
+- `NestReader.Read()` returns `Nest`.
+- `NestWriter(Nest nest)` constructor preserved.
+- `NestWriter.Write(string file)` returns `bool`.
+
+### Callers (no changes needed)
+
+- `MainForm.cs:329` — `new NestReader(path)`
+- `MainForm.cs:363` — `new NestReader(dlg.FileName)`
+- `EditNestForm.cs:212` — `new NestWriter(Nest)`
+- `EditNestForm.cs:223` — `new NestWriter(nst)`
+- `Document.cs:27` — `new NestWriter(Nest)`
+- `OpenNest.Console/Program.cs:94` — `new NestReader(nestFile)`
+- `OpenNest.Console/Program.cs:190` — `new NestWriter(nest)`
+- `OpenNest.Mcp/InputTools.cs:30` — `new NestReader(path)`