feat: allow re-selecting parts with existing lead-ins and use magenta preview

Remove LeadInsLocked guard so parts can be re-selected for lead-in
re-placement. Change preview color from yellow to magenta for better
visibility against the cyan contour highlight.

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

OpenNest.Core/CNC/CuttingStrategy/ContourCuttingStrategy.cs

@@ -1,4 +1,5 @@
 using OpenNest.Geometry;
+using OpenNest.Math;
 using System.Collections.Generic;
 
 namespace OpenNest.CNC.CuttingStrategy
@@ -59,9 +60,18 @@ namespace OpenNest.CNC.CuttingStrategy
 
                 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));
+
+                if (Parameters.TabsEnabled && Parameters.TabConfig != null)
+                {
+                    var trimmed = TrimShapeForTab(reindexed, closestPt, Parameters.TabConfig.Size);
+                    result.Codes.AddRange(ConvertShapeToMoves(trimmed, closestPt));
+                    result.Codes.AddRange(leadOut.Generate(closestPt, normal, winding));
+                }
+                else
+                {
+                    result.Codes.AddRange(ConvertShapeToMoves(reindexed, closestPt));
+                    result.Codes.AddRange(leadOut.Generate(closestPt, normal, winding));
+                }
 
                 currentPoint = closestPt;
             }
@@ -80,9 +90,18 @@ namespace OpenNest.CNC.CuttingStrategy
 
                 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));
+
+                if (Parameters.TabsEnabled && Parameters.TabConfig != null)
+                {
+                    var trimmed = TrimShapeForTab(reindexed, perimeterPt, Parameters.TabConfig.Size);
+                    result.Codes.AddRange(ConvertShapeToMoves(trimmed, perimeterPt));
+                    result.Codes.AddRange(leadOut.Generate(perimeterPt, normal, winding));
+                }
+                else
+                {
+                    result.Codes.AddRange(ConvertShapeToMoves(reindexed, perimeterPt));
+                    result.Codes.AddRange(leadOut.Generate(perimeterPt, normal, winding));
+                }
             }
 
             // Convert to incremental mode to match the convention used by
@@ -150,6 +169,12 @@ namespace OpenNest.CNC.CuttingStrategy
             {
                 // Radial direction from center to point
                 normal = point.AngleFrom(arc.Center);
+
+                // For CCW arcs the radial points the wrong way — flip it.
+                // CW arcs are convex features (corners) where radial = outward.
+                // CCW arcs are concave features (slots) where radial = inward.
+                if (arc.Rotation == RotationType.CCW)
+                    normal += System.Math.PI;
             }
             else if (entity is Circle circle)
             {
@@ -238,6 +263,70 @@ namespace OpenNest.CNC.CuttingStrategy
             };
         }
 
+        private static Shape TrimShapeForTab(Shape shape, Vector center, double tabSize)
+        {
+            var tabCircle = new Circle(center, tabSize);
+            var entities = new List<Entity>(shape.Entities);
+
+            // Trim end: walk backward removing entities inside the tab circle
+            while (entities.Count > 0)
+            {
+                var entity = entities[entities.Count - 1];
+                if (entity.Intersects(tabCircle, out var pts) && pts.Count > 0)
+                {
+                    // Find intersection furthest from center (furthest along path from end)
+                    var best = pts[0];
+                    var bestDist = best.DistanceTo(center);
+                    for (var j = 1; j < pts.Count; j++)
+                    {
+                        var dist = pts[j].DistanceTo(center);
+                        if (dist > bestDist)
+                        {
+                            best = pts[j];
+                            bestDist = dist;
+                        }
+                    }
+
+                    if (entity is Line line)
+                    {
+                        var (first, _) = line.SplitAt(best);
+                        entities.RemoveAt(entities.Count - 1);
+                        if (first != null)
+                            entities.Add(first);
+                    }
+                    else if (entity is Arc arc)
+                    {
+                        var (first, _) = arc.SplitAt(best);
+                        entities.RemoveAt(entities.Count - 1);
+                        if (first != null)
+                            entities.Add(first);
+                    }
+
+                    break;
+                }
+
+                // No intersection — entity is entirely inside circle, remove it
+                if (EntityStartPoint(entity).DistanceTo(center) <= tabSize + Tolerance.Epsilon)
+                {
+                    entities.RemoveAt(entities.Count - 1);
+                    continue;
+                }
+
+                break;
+            }
+
+            var result = new Shape();
+            result.Entities.AddRange(entities);
+            return result;
+        }
+
+        private static Vector EntityStartPoint(Entity entity)
+        {
+            if (entity is Line line) return line.StartPoint;
+            if (entity is Arc arc) return arc.StartPoint();
+            return Vector.Zero;
+        }
+
         private List<ICode> ConvertShapeToMoves(Shape shape, Vector startPoint, LayerType layer = LayerType.Display)
         {
             var moves = new List<ICode>();

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

@@ -23,7 +23,7 @@ namespace OpenNest.CNC.CuttingStrategy
 
         public override Vector GetPiercePoint(Vector contourStartPoint, double contourNormalAngle)
         {
-            var approachAngle = contourNormalAngle + Angle.HalfPI - Angle.ToRadians(ApproachAngle);
+            var approachAngle = contourNormalAngle - Angle.HalfPI + Angle.ToRadians(ApproachAngle);
             return new Vector(
                 contourStartPoint.X + Length * System.Math.Cos(approachAngle),
                 contourStartPoint.Y + Length * System.Math.Sin(approachAngle));

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

@@ -16,7 +16,7 @@ namespace OpenNest.CNC.CuttingStrategy
         {
             var piercePoint = GetPiercePoint(contourStartPoint, contourNormalAngle);
 
-            var secondAngle = contourNormalAngle + Angle.HalfPI - Angle.ToRadians(ApproachAngle1);
+            var secondAngle = contourNormalAngle - Angle.HalfPI + Angle.ToRadians(ApproachAngle1);
             var midPoint = new Vector(
                 contourStartPoint.X + Length2 * System.Math.Cos(secondAngle),
                 contourStartPoint.Y + Length2 * System.Math.Sin(secondAngle));
@@ -31,7 +31,7 @@ namespace OpenNest.CNC.CuttingStrategy
 
         public override Vector GetPiercePoint(Vector contourStartPoint, double contourNormalAngle)
         {
-            var secondAngle = contourNormalAngle + Angle.HalfPI - Angle.ToRadians(ApproachAngle1);
+            var secondAngle = contourNormalAngle - Angle.HalfPI + Angle.ToRadians(ApproachAngle1);
             var midX = contourStartPoint.X + Length2 * System.Math.Cos(secondAngle);
             var midY = contourStartPoint.Y + Length2 * System.Math.Sin(secondAngle);
 

OpenNest.Core/IConfigurablePostProcessor.cs

@@ -0,0 +1,9 @@
+namespace OpenNest
+{
+    public interface IConfigurablePostProcessor : IPostProcessor
+    {
+        object Config { get; }
+
+        void SaveConfig();
+    }
+}

OpenNest.Posts.Cincinnati/CincinnatiFeatureWriter.cs

@@ -23,6 +23,12 @@ public sealed class FeatureContext
     public string LibraryFile { get; set; } = "";
     public double CutDistance { get; set; }
     public double SheetDiagonal { get; set; }
+
+    /// <summary>
+    /// Part location on the plate. Added to all output X/Y coordinates
+    /// so part-relative programs become plate-absolute under G90.
+    /// </summary>
+    public Vector PartLocation { get; set; } = Vector.Zero;
 }
 
 /// <summary>
@@ -51,12 +57,13 @@ public sealed class CincinnatiFeatureWriter
         var currentPos = Vector.Zero;
         var lastFeedVar = "";
         var kerfEmitted = false;
+        var offset = ctx.PartLocation;
 
         // Find the pierce point from the first rapid move
         var piercePoint = FindPiercePoint(ctx.Codes);
 
         // 1. Rapid to pierce point (with line number if configured)
-        WriteRapidToPierce(writer, ctx.FeatureNumber, piercePoint);
+        WriteRapidToPierce(writer, ctx.FeatureNumber, piercePoint, offset);
 
         // 2. Part name comment on first feature of each part
         if (ctx.IsFirstFeatureOfPart && !string.IsNullOrEmpty(ctx.PartName))
@@ -105,7 +112,7 @@ public sealed class CincinnatiFeatureWriter
                     kerfEmitted = true;
                 }
 
-                sb.Append($"G1 X{_fmt.FormatCoord(linear.EndPoint.X)} Y{_fmt.FormatCoord(linear.EndPoint.Y)}");
+                sb.Append($"G1 X{_fmt.FormatCoord(linear.EndPoint.X + offset.X)} Y{_fmt.FormatCoord(linear.EndPoint.Y + offset.Y)}");
 
                 // Feedrate — etch always uses process feedrate
                 var feedVar = ctx.IsEtch ? "#148" : GetLinearFeedVariable(linear.Layer);
@@ -131,7 +138,7 @@ public sealed class CincinnatiFeatureWriter
 
                 // G2 = CW, G3 = CCW
                 var gCode = arc.Rotation == RotationType.CW ? "G2" : "G3";
-                sb.Append($"{gCode} X{_fmt.FormatCoord(arc.EndPoint.X)} Y{_fmt.FormatCoord(arc.EndPoint.Y)}");
+                sb.Append($"{gCode} X{_fmt.FormatCoord(arc.EndPoint.X + offset.X)} Y{_fmt.FormatCoord(arc.EndPoint.Y + offset.Y)}");
 
                 // Convert absolute center to incremental I/J
                 var i = arc.CenterPoint.X - currentPos.X;
@@ -188,14 +195,14 @@ public sealed class CincinnatiFeatureWriter
         return Vector.Zero;
     }
 
-    private void WriteRapidToPierce(TextWriter writer, int featureNumber, Vector piercePoint)
+    private void WriteRapidToPierce(TextWriter writer, int featureNumber, Vector piercePoint, Vector offset)
     {
         var sb = new StringBuilder();
 
         if (_config.UseLineNumbers)
             sb.Append($"N{featureNumber} ");
 
-        sb.Append($"G0 X{_fmt.FormatCoord(piercePoint.X)} Y{_fmt.FormatCoord(piercePoint.Y)}");
+        sb.Append($"G0 X{_fmt.FormatCoord(piercePoint.X + offset.X)} Y{_fmt.FormatCoord(piercePoint.Y + offset.Y)}");
 
         writer.WriteLine(sb.ToString());
     }

OpenNest.Posts.Cincinnati/CincinnatiPostConfig.cs

@@ -1,4 +1,5 @@
 using System.Collections.Generic;
+using System.ComponentModel;
 
 namespace OpenNest.Posts.Cincinnati
 {
@@ -92,205 +93,159 @@ namespace OpenNest.Posts.Cincinnati
     /// </summary>
     public sealed class CincinnatiPostConfig
     {
-        /// <summary>
-        /// Gets or sets the configuration name/identifier.
-        /// Default: "CL940"
-        /// </summary>
+        [Category("1. Output")]
+        [DisplayName("Configuration Name")]
+        [Description("Configuration name/identifier (e.g. CL940).")]
         public string ConfigurationName { get; set; } = "CL940";
 
-        /// <summary>
-        /// Gets or sets the units for posted output.
-        /// Default: Units.Inches
-        /// </summary>
+        [Category("1. Output")]
+        [DisplayName("Posted Units")]
+        [Description("Units for posted output (Inches or Millimeters).")]
         public Units PostedUnits { get; set; } = Units.Inches;
 
-        /// <summary>
-        /// Gets or sets the decimal accuracy for numeric output.
-        /// Default: 4
-        /// </summary>
+        [Category("1. Output")]
+        [DisplayName("Decimal Accuracy")]
+        [Description("Number of decimal places for numeric output.")]
         public int PostedAccuracy { get; set; } = 4;
 
-        /// <summary>
-        /// Gets or sets how coordinate positioning is handled between parts.
-        /// Default: CoordinateMode.G92
-        /// </summary>
-        public CoordinateMode CoordModeBetweenParts { get; set; } = CoordinateMode.G92;
-
-        /// <summary>
-        /// Gets or sets whether to use subprograms for sheet operations.
-        /// Default: true
-        /// </summary>
-        public bool UseSheetSubprograms { get; set; } = true;
-
-        /// <summary>
-        /// Gets or sets the starting subprogram number for sheet operations.
-        /// Default: 101
-        /// </summary>
-        public int SheetSubprogramStart { get; set; } = 101;
-
-        /// <summary>
-        /// Gets or sets whether to use M98 sub-programs for part geometry.
-        /// When enabled, each unique part geometry is written as a reusable sub-program
-        /// called via M98, reducing output size for nests with repeated parts.
-        /// Default: false
-        /// </summary>
-        public bool UsePartSubprograms { get; set; } = false;
-
-        /// <summary>
-        /// Gets or sets the starting sub-program number for part geometry sub-programs.
-        /// Default: 200
-        /// </summary>
-        public int PartSubprogramStart { get; set; } = 200;
-
-        /// <summary>
-        /// Gets or sets the subprogram number for variable declarations.
-        /// Default: 100
-        /// </summary>
-        public int VariableDeclarationSubprogram { get; set; } = 100;
-
-        /// <summary>
-        /// Gets or sets how G89 parameters are provided.
-        /// Default: G89Mode.LibraryFile
-        /// </summary>
-        public G89Mode ProcessParameterMode { get; set; } = G89Mode.LibraryFile;
-
-        /// <summary>
-        /// Gets or sets the default assist gas when Nest.AssistGas is empty.
-        /// Default: "O2"
-        /// </summary>
-        public string DefaultAssistGas { get; set; } = "O2";
-
-        /// <summary>
-        /// Gets or sets the gas used for etch operations.
-        /// Independent of the cutting assist gas — etch typically requires a specific gas.
-        /// Default: "N2"
-        /// </summary>
-        public string DefaultEtchGas { get; set; } = "N2";
-
-        /// <summary>
-        /// Gets or sets the material-to-library mapping for cut operations.
-        /// Each entry maps (material, thickness, gas) to a G89 library file.
-        /// </summary>
-        public List<MaterialLibraryEntry> MaterialLibraries { get; set; } = new();
-
-        /// <summary>
-        /// Gets or sets the gas-to-library mapping for etch operations.
-        /// Each entry maps a gas type to a G89 etch library file.
-        /// </summary>
-        public List<EtchLibraryEntry> EtchLibraries { get; set; } = new();
-
-        /// <summary>
-        /// Gets or sets whether to use exact stop mode (G61).
-        /// Default: false
-        /// </summary>
-        public bool UseExactStopMode { get; set; } = false;
-
-        /// <summary>
-        /// Gets or sets where kerf compensation is applied.
-        /// Default: KerfMode.ControllerSide
-        /// </summary>
-        public KerfMode KerfCompensation { get; set; } = KerfMode.ControllerSide;
-
-        /// <summary>
-        /// Gets or sets the default side for kerf compensation.
-        /// Default: KerfSide.Left
-        /// </summary>
-        public KerfSide DefaultKerfSide { get; set; } = KerfSide.Left;
-
-        /// <summary>
-        /// Gets or sets how M47 is used in interior cuts.
-        /// Default: M47Mode.Always
-        /// </summary>
-        public M47Mode InteriorM47 { get; set; } = M47Mode.Always;
-
-        /// <summary>
-        /// Gets or sets how M47 is used in exterior cuts.
-        /// Default: M47Mode.Always
-        /// </summary>
-        public M47Mode ExteriorM47 { get; set; } = M47Mode.Always;
-
-        /// <summary>
-        /// Gets or sets the safety head raise distance (in machine units).
-        /// Default: 2000
-        /// </summary>
-        public int? SafetyHeadraiseDistance { get; set; } = 2000;
-
-        /// <summary>
-        /// Gets or sets the distance threshold for M47 override.
-        /// Default: null
-        /// </summary>
-        public double? M47OverrideDistanceThreshold { get; set; } = null;
-
-        /// <summary>
-        /// Gets or sets whether to use anti-dive functionality.
-        /// Default: true
-        /// </summary>
-        public bool UseAntiDive { get; set; } = true;
-
-        /// <summary>
-        /// Gets or sets whether to use smart rapids optimization.
-        /// Default: false
-        /// </summary>
-        public bool UseSmartRapids { get; set; } = false;
-
-        /// <summary>
-        /// Gets or sets when pallet exchange occurs.
-        /// Default: PalletMode.EndOfSheet
-        /// </summary>
-        public PalletMode PalletExchange { get; set; } = PalletMode.EndOfSheet;
-
-        /// <summary>
-        /// Gets or sets whether to use line numbers in output.
-        /// Default: true
-        /// </summary>
+        [Category("1. Output")]
+        [DisplayName("Use Line Numbers")]
+        [Description("Include line numbers in output.")]
         public bool UseLineNumbers { get; set; } = true;
 
-        /// <summary>
-        /// Gets or sets the starting line number for features.
-        /// Default: 1
-        /// </summary>
+        [Category("1. Output")]
+        [DisplayName("Feature Line Number Start")]
+        [Description("Starting line number for features.")]
         public int FeatureLineNumberStart { get; set; } = 1;
 
-        /// <summary>
-        /// Gets or sets whether to use speed/gas commands.
-        /// Default: false
-        /// </summary>
+        [Category("2. Subprograms")]
+        [DisplayName("Use Sheet Subprograms")]
+        [Description("Use subprograms for sheet operations.")]
+        public bool UseSheetSubprograms { get; set; } = true;
+
+        [Category("2. Subprograms")]
+        [DisplayName("Sheet Subprogram Start")]
+        [Description("Starting subprogram number for sheet operations.")]
+        public int SheetSubprogramStart { get; set; } = 101;
+
+        [Category("2. Subprograms")]
+        [DisplayName("Use Part Subprograms")]
+        [Description("Use M98 sub-programs for part geometry. Reduces output size for repeated parts.")]
+        public bool UsePartSubprograms { get; set; } = false;
+
+        [Category("2. Subprograms")]
+        [DisplayName("Part Subprogram Start")]
+        [Description("Starting sub-program number for part geometry sub-programs.")]
+        public int PartSubprogramStart { get; set; } = 200;
+
+        [Category("2. Subprograms")]
+        [DisplayName("Variable Declaration Subprogram")]
+        [Description("Subprogram number for variable declarations.")]
+        public int VariableDeclarationSubprogram { get; set; } = 100;
+
+        [Category("3. Positioning")]
+        [DisplayName("Coordinate Mode Between Parts")]
+        [Description("How coordinate positioning is handled between parts (G92, G91, or G53).")]
+        public CoordinateMode CoordModeBetweenParts { get; set; } = CoordinateMode.G92;
+
+        [Category("4. Process")]
+        [DisplayName("Process Parameter Mode")]
+        [Description("How G89 parameters are provided (LibraryFile or Explicit).")]
+        public G89Mode ProcessParameterMode { get; set; } = G89Mode.LibraryFile;
+
+        [Category("4. Process")]
+        [DisplayName("Default Assist Gas")]
+        [Description("Default assist gas when Nest.AssistGas is empty.")]
+        public string DefaultAssistGas { get; set; } = "O2";
+
+        [Category("4. Process")]
+        [DisplayName("Default Etch Gas")]
+        [Description("Gas used for etch operations.")]
+        public string DefaultEtchGas { get; set; } = "N2";
+
+        [Category("4. Process")]
+        [DisplayName("Use Exact Stop Mode")]
+        [Description("Enable exact stop mode (G61).")]
+        public bool UseExactStopMode { get; set; } = false;
+
+        [Category("4. Process")]
+        [DisplayName("Use Speed/Gas Commands")]
+        [Description("Enable speed/gas commands in output.")]
         public bool UseSpeedGas { get; set; } = false;
 
-        /// <summary>
-        /// Gets or sets the feedrate percentage for lead-in moves.
-        /// Default: 0.5 (50%)
-        /// </summary>
+        [Category("4. Process")]
+        [DisplayName("Use Anti-Dive")]
+        [Description("Enable anti-dive functionality.")]
+        public bool UseAntiDive { get; set; } = true;
+
+        [Category("4. Process")]
+        [DisplayName("Use Smart Rapids")]
+        [Description("Enable smart rapids optimization.")]
+        public bool UseSmartRapids { get; set; } = false;
+
+        [Category("5. Kerf")]
+        [DisplayName("Kerf Compensation")]
+        [Description("Where kerf compensation is applied (ControllerSide or PreApplied).")]
+        public KerfMode KerfCompensation { get; set; } = KerfMode.ControllerSide;
+
+        [Category("5. Kerf")]
+        [DisplayName("Default Kerf Side")]
+        [Description("Default side for kerf compensation (Left or Right).")]
+        public KerfSide DefaultKerfSide { get; set; } = KerfSide.Left;
+
+        [Category("6. M47 (Optional Stop)")]
+        [DisplayName("Interior M47")]
+        [Description("How M47 is used in interior cuts.")]
+        public M47Mode InteriorM47 { get; set; } = M47Mode.Always;
+
+        [Category("6. M47 (Optional Stop)")]
+        [DisplayName("Exterior M47")]
+        [Description("How M47 is used in exterior cuts.")]
+        public M47Mode ExteriorM47 { get; set; } = M47Mode.Always;
+
+        [Category("6. M47 (Optional Stop)")]
+        [DisplayName("M47 Override Distance Threshold")]
+        [Description("Distance threshold for M47 override. Null = no override.")]
+        public double? M47OverrideDistanceThreshold { get; set; } = null;
+
+        [Category("7. Safety")]
+        [DisplayName("Safety Headraise Distance")]
+        [Description("Safety head raise distance in machine units. Null = disabled.")]
+        public int? SafetyHeadraiseDistance { get; set; } = 2000;
+
+        [Category("8. Pallet")]
+        [DisplayName("Pallet Exchange")]
+        [Description("When pallet exchange occurs (None, EndOfSheet, or StartAndEnd).")]
+        public PalletMode PalletExchange { get; set; } = PalletMode.EndOfSheet;
+
+        [Category("9. Feedrates")]
+        [DisplayName("Lead-In Feedrate %")]
+        [Description("Feedrate percentage for lead-in moves (e.g. 0.5 = 50%).")]
         public double LeadInFeedratePercent { get; set; } = 0.5;
 
-        /// <summary>
-        /// Gets or sets the feedrate percentage for lead-in arc-to-line moves.
-        /// Default: 0.5 (50%)
-        /// </summary>
+        [Category("9. Feedrates")]
+        [DisplayName("Lead-In Arc Line 2 Feedrate %")]
+        [Description("Feedrate percentage for lead-in arc-to-line moves.")]
         public double LeadInArcLine2FeedratePercent { get; set; } = 0.5;
 
-        /// <summary>
-        /// Gets or sets the feedrate percentage for lead-out moves.
-        /// Default: 0.5 (50%)
-        /// </summary>
+        [Category("9. Feedrates")]
+        [DisplayName("Lead-Out Feedrate %")]
+        [Description("Feedrate percentage for lead-out moves.")]
         public double LeadOutFeedratePercent { get; set; } = 0.5;
 
-        /// <summary>
-        /// Gets or sets the feedrate multiplier for circular cuts.
-        /// Default: 0.8 (80%)
-        /// </summary>
+        [Category("9. Feedrates")]
+        [DisplayName("Circle Feedrate Multiplier")]
+        [Description("Feedrate multiplier for circular cuts (e.g. 0.8 = 80%).")]
         public double CircleFeedrateMultiplier { get; set; } = 0.8;
 
-        /// <summary>
-        /// Gets or sets the arc feedrate calculation mode.
-        /// Default: ArcFeedrateMode.None
-        /// </summary>
+        [Category("9. Feedrates")]
+        [DisplayName("Arc Feedrate Mode")]
+        [Description("Arc feedrate calculation mode (None, Percentages, or Variables).")]
         public ArcFeedrateMode ArcFeedrate { get; set; } = ArcFeedrateMode.None;
 
-        /// <summary>
-        /// Gets or sets the radius-based arc feedrate ranges.
-        /// Ranges are matched from smallest MaxRadius to largest.
-        /// </summary>
+        [Category("9. Feedrates")]
+        [DisplayName("Arc Feedrate Ranges")]
+        [Description("Radius-based arc feedrate ranges. Matched from smallest to largest MaxRadius.")]
         public List<ArcFeedrateRange> ArcFeedrateRanges { get; set; } = new()
         {
             new() { MaxRadius = 0.125, FeedratePercent = 0.25, VariableNumber = 123 },
@@ -298,17 +253,25 @@ namespace OpenNest.Posts.Cincinnati
             new() { MaxRadius = 4.500, FeedratePercent = 0.80, VariableNumber = 125 }
         };
 
-        /// <summary>
-        /// Gets or sets the variable number for sheet width.
-        /// Default: 110
-        /// </summary>
+        [Category("A. Variables")]
+        [DisplayName("Sheet Width Variable")]
+        [Description("Variable number for sheet width.")]
         public int SheetWidthVariable { get; set; } = 110;
 
-        /// <summary>
-        /// Gets or sets the variable number for sheet length.
-        /// Default: 111
-        /// </summary>
+        [Category("A. Variables")]
+        [DisplayName("Sheet Length Variable")]
+        [Description("Variable number for sheet length.")]
         public int SheetLengthVariable { get; set; } = 111;
+
+        [Category("B. Libraries")]
+        [DisplayName("Material Libraries")]
+        [Description("Material-to-library mapping for cut operations. Maps (material, thickness, gas) to a G89 library file.")]
+        public List<MaterialLibraryEntry> MaterialLibraries { get; set; } = new();
+
+        [Category("B. Libraries")]
+        [DisplayName("Etch Libraries")]
+        [Description("Gas-to-library mapping for etch operations.")]
+        public List<EtchLibraryEntry> EtchLibraries { get; set; } = new();
     }
 
     public class MaterialLibraryEntry

OpenNest.Posts.Cincinnati/CincinnatiPostProcessor.cs

@@ -9,7 +9,7 @@ using OpenNest.CNC;
 
 namespace OpenNest.Posts.Cincinnati
 {
-    public sealed class CincinnatiPostProcessor : IPostProcessor
+    public sealed class CincinnatiPostProcessor : IConfigurablePostProcessor
     {
         private static readonly JsonSerializerOptions JsonOptions = new()
         {
@@ -23,6 +23,8 @@ namespace OpenNest.Posts.Cincinnati
 
         public CincinnatiPostConfig Config { get; }
 
+        object IConfigurablePostProcessor.Config => Config;
+
         public CincinnatiPostProcessor()
         {
             var configPath = GetConfigPath();

OpenNest.Posts.Cincinnati/CincinnatiSheetWriter.cs

@@ -153,7 +153,8 @@ public sealed class CincinnatiSheetWriter
                         IsEtch = isEtch,
                         LibraryFile = isEtch ? etchLibrary : cutLibrary,
                         CutDistance = cutDistance,
-                        SheetDiagonal = sheetDiagonal
+                        SheetDiagonal = sheetDiagonal,
+                        PartLocation = part.Location
                     };
 
                     _featureWriter.Write(w, ctx);
@@ -240,7 +241,8 @@ public sealed class CincinnatiSheetWriter
                 IsEtch = isEtch,
                 LibraryFile = isEtch ? etchLibrary : cutLibrary,
                 CutDistance = cutDistance,
-                SheetDiagonal = sheetDiagonal
+                SheetDiagonal = sheetDiagonal,
+                PartLocation = part.Location
             };
 
             _featureWriter.Write(w, ctx);

OpenNest.Tests/Cincinnati/CincinnatiPostProcessorTests.cs

@@ -121,6 +121,17 @@ public class CincinnatiPostProcessorTests
         Assert.Equal("OpenNest", pp.Author);
     }
 
+    [Fact]
+    public void Post_ImplementsIConfigurablePostProcessor()
+    {
+        var post = new CincinnatiPostProcessor(new CincinnatiPostConfig());
+        var configurable = post as IConfigurablePostProcessor;
+
+        Assert.NotNull(configurable);
+        Assert.NotNull(configurable.Config);
+        Assert.IsType<CincinnatiPostConfig>(configurable.Config);
+    }
+
     [Fact]
     public void Post_SkipsEmptyPlates()
     {

OpenNest.Tests/Cincinnati/CincinnatiSheetWriterTests.cs

@@ -280,6 +280,67 @@ public class CincinnatiSheetWriterTests
         Assert.False(FeatureUtils.IsEtch(codes));
     }
 
+    [Fact]
+    public void WriteSheet_InlineCoordinates_AreAbsoluteOnPlate()
+    {
+        var config = new CincinnatiPostConfig { PostedAccuracy = 4 };
+        // Part program is at origin: (0,0) to (2,0) to (2,2) to (0,2) to (0,0)
+        var pgm = new Program();
+        pgm.Codes.Add(new RapidMove(0, 0));
+        pgm.Codes.Add(new LinearMove(2, 0));
+        pgm.Codes.Add(new LinearMove(2, 2));
+        pgm.Codes.Add(new LinearMove(0, 2));
+        pgm.Codes.Add(new LinearMove(0, 0));
+
+        var plate = new Plate(48.0, 96.0);
+        // Place part at (10.5, 5.25) on the plate to produce non-integer coordinates
+        plate.Parts.Add(new Part(new Drawing("Square", pgm), new Vector(10.5, 5.25)));
+
+        var sb = new StringBuilder();
+        using var sw = new StringWriter(sb);
+        var sheetWriter = new CincinnatiSheetWriter(config, new ProgramVariableManager());
+
+        sheetWriter.Write(sw, plate, "TestNest", 1, 101, "", "");
+
+        var output = sb.ToString();
+        // Under G90, coordinates must be plate-absolute (part coords + part location)
+        Assert.Contains("G0 X10.5 Y5.25", output);      // rapid to pierce
+        Assert.Contains("G1 X12.5 Y5.25", output);       // (2,0) + (10.5,5.25)
+        Assert.Contains("G1 X12.5 Y7.25", output);       // (2,2) + (10.5,5.25)
+        Assert.Contains("G1 X10.5 Y7.25", output);       // (0,2) + (10.5,5.25)
+        Assert.Contains("G1 X10.5 Y5.25", output);       // (0,0) + (10.5,5.25)
+    }
+
+    [Fact]
+    public void WriteSheet_TwoPartsAtDifferentLocations_HaveDistinctAbsoluteCoords()
+    {
+        var config = new CincinnatiPostConfig { PostedAccuracy = 4 };
+        var pgm = new Program();
+        pgm.Codes.Add(new RapidMove(0, 0));
+        pgm.Codes.Add(new LinearMove(1, 0));
+        pgm.Codes.Add(new LinearMove(1, 1));
+        pgm.Codes.Add(new LinearMove(0, 0));
+
+        var drawing = new Drawing("Tri", pgm);
+        var plate = new Plate(48.0, 96.0);
+        plate.Parts.Add(new Part(drawing, new Vector(5.5, 3.25)));
+        plate.Parts.Add(new Part(drawing, new Vector(20.5, 10.25)));
+
+        var sb = new StringBuilder();
+        using var sw = new StringWriter(sb);
+        var sheetWriter = new CincinnatiSheetWriter(config, new ProgramVariableManager());
+
+        sheetWriter.Write(sw, plate, "TestNest", 1, 101, "", "");
+
+        var output = sb.ToString();
+        // First part at (5.5, 3.25)
+        Assert.Contains("G0 X5.5 Y3.25", output);
+        Assert.Contains("G1 X6.5 Y3.25", output);
+        // Second part at (20.5, 10.25)
+        Assert.Contains("G0 X20.5 Y10.25", output);
+        Assert.Contains("G1 X21.5 Y10.25", output);
+    }
+
     private static Program CreateSimpleProgram()
     {
         var pgm = new Program();

OpenNest/Actions/ActionLeadIn.cs

@@ -23,7 +23,10 @@ namespace OpenNest.Actions
         private ContourType snapContourType;
         private double snapNormal;
         private bool hasSnap;
+        private ShapeInfo hoveredContour;
         private ContextMenuStrip contextMenu;
+        private static readonly Brush grayOverlay = new SolidBrush(Color.FromArgb(160, 180, 180, 180));
+        private static readonly Pen highlightPen = new Pen(Color.Cyan, 2.5f);
 
         public ActionLeadIn(PlateView plateView)
             : base(plateView)
@@ -54,6 +57,7 @@ namespace OpenNest.Actions
             profile = null;
             contours = null;
             hasSnap = false;
+            hoveredContour = null;
             plateView.Invalidate();
         }
 
@@ -77,6 +81,7 @@ namespace OpenNest.Actions
             // Find closest contour and point
             var bestDist = double.MaxValue;
             hasSnap = false;
+            hoveredContour = null;
 
             foreach (var info in contours)
             {
@@ -91,6 +96,7 @@ namespace OpenNest.Actions
                     snapContourType = info.ContourType;
                     snapNormal = ContourCuttingStrategy.ComputeNormal(closest, entity, info.ContourType);
                     hasSnap = true;
+                    hoveredContour = info;
                 }
             }
 
@@ -134,6 +140,35 @@ namespace OpenNest.Actions
 
         private void OnPaint(object sender, PaintEventArgs e)
         {
+            var g = e.Graphics;
+
+            // Gray overlay on all parts except the selected one
+            foreach (var lp in plateView.LayoutParts)
+            {
+                if (lp == selectedLayoutPart)
+                    continue;
+
+                if (lp.Path != null)
+                    g.FillPath(grayOverlay, lp.Path);
+            }
+
+            // Highlight the hovered contour
+            if (hoveredContour != null && selectedPart != null)
+            {
+                using var contourPath = hoveredContour.Shape.GetGraphicsPath();
+
+                // Translate from local part space to world space, then apply view transform
+                using var contourMatrix = new Matrix();
+                contourMatrix.Translate((float)selectedPart.Location.X, (float)selectedPart.Location.Y);
+                contourMatrix.Multiply(plateView.Matrix, MatrixOrder.Append);
+                contourPath.Transform(contourMatrix);
+
+                var prevSmooth = g.SmoothingMode;
+                g.SmoothingMode = SmoothingMode.AntiAlias;
+                g.DrawPath(highlightPen, contourPath);
+                g.SmoothingMode = prevSmooth;
+            }
+
             if (!hasSnap || selectedPart == null)
                 return;
 
@@ -182,7 +217,6 @@ namespace OpenNest.Actions
             var piercePoint = leadIn.GetPiercePoint(snapPoint, snapNormal);
             var worldPierce = TransformToWorld(piercePoint);
 
-            var g = e.Graphics;
             var oldSmooth = g.SmoothingMode;
             g.SmoothingMode = SmoothingMode.AntiAlias;
 
@@ -190,12 +224,12 @@ namespace OpenNest.Actions
             var pt1 = plateView.PointWorldToGraph(worldPierce);
             var pt2 = plateView.PointWorldToGraph(worldSnap);
 
-            using var pen = new Pen(Color.Yellow, 2.0f / plateView.ViewScale);
-            g.DrawLine(pen, pt1, pt2);
+            using var previewPen = new Pen(Color.Magenta, 2.0f / plateView.ViewScale);
+            g.DrawLine(previewPen, pt1, pt2);
 
             // Draw a small circle at the pierce point
             var radius = 3.0f / plateView.ViewScale;
-            g.FillEllipse(Brushes.Yellow, pt1.X - radius, pt1.Y - radius, radius * 2, radius * 2);
+            g.FillEllipse(Brushes.Magenta, pt1.X - radius, pt1.Y - radius, radius * 2, radius * 2);
 
             // Draw a small circle at the contour start point
             g.FillEllipse(Brushes.Lime, pt2.X - radius, pt2.Y - radius, radius * 2, radius * 2);
@@ -215,10 +249,6 @@ namespace OpenNest.Actions
             if (part.BaseDrawing.IsCutOff)
                 return;
 
-            // If part already has locked lead-ins, don't allow re-placement
-            if (part.LeadInsLocked)
-                return;
-
             selectedLayoutPart = layoutPart;
             selectedPart = part;
 
@@ -312,6 +342,7 @@ namespace OpenNest.Actions
             profile = null;
             contours = null;
             hasSnap = false;
+            hoveredContour = null;
             plateView.Invalidate();
         }
 

OpenNest/Controls/PlateRenderer.cs

@@ -515,23 +515,22 @@ namespace OpenNest.Controls
 
         private void DrawAllCutDirectionArrows(Graphics g)
         {
-            using var pen = new Pen(Color.FromArgb(220, Color.DarkCyan), 1.5f);
-            using var brush = new SolidBrush(Color.FromArgb(220, Color.DarkCyan));
+            using var pen = new Pen(Color.FromArgb(220, Color.Black), 1.5f);
 
             var arrowSpacingWorld = view.LengthGuiToWorld(60f);
-            var arrowSize = 5f;
+            var arrowSize = 6f;
 
             for (var i = 0; i < view.Plate.Parts.Count; ++i)
             {
                 var part = view.Plate.Parts[i];
                 var pgm = part.Program;
                 var pos = part.Location;
-                DrawProgramCutDirectionArrows(g, pgm, ref pos, pen, brush, arrowSpacingWorld, arrowSize);
+                DrawProgramCutDirectionArrows(g, pgm, ref pos, pen, arrowSpacingWorld, arrowSize);
             }
         }
 
         private void DrawProgramCutDirectionArrows(Graphics g, Program pgm, ref Vector pos,
-            Pen pen, Brush brush, double spacing, float arrowSize)
+            Pen pen, double spacing, float arrowSize)
         {
             for (var i = 0; i < pgm.Length; ++i)
             {
@@ -541,7 +540,7 @@ namespace OpenNest.Controls
                 {
                     var subpgm = (SubProgramCall)code;
                     if (subpgm.Program != null)
-                        DrawProgramCutDirectionArrows(g, subpgm.Program, ref pos, pen, brush, spacing, arrowSize);
+                        DrawProgramCutDirectionArrows(g, subpgm.Program, ref pos, pen, spacing, arrowSize);
                     continue;
                 }
 
@@ -555,7 +554,7 @@ namespace OpenNest.Controls
                 {
                     var line = (LinearMove)code;
                     if (!line.Suppressed)
-                        DrawLineDirectionArrows(g, pos, endpt, brush, spacing, arrowSize);
+                        DrawLineDirectionArrows(g, pos, endpt, pen, spacing, arrowSize);
                 }
                 else if (code.Type == CodeType.ArcMove)
                 {
@@ -565,7 +564,7 @@ namespace OpenNest.Controls
                         var center = pgm.Mode == Mode.Incremental
                             ? arc.CenterPoint + pos
                             : arc.CenterPoint;
-                        DrawArcDirectionArrows(g, pos, endpt, center, arc.Rotation, brush, spacing, arrowSize);
+                        DrawArcDirectionArrows(g, pos, endpt, center, arc.Rotation, pen, spacing, arrowSize);
                     }
                 }
 
@@ -574,7 +573,7 @@ namespace OpenNest.Controls
         }
 
         private void DrawLineDirectionArrows(Graphics g, Vector start, Vector end,
-            Brush brush, double spacing, float arrowSize)
+            Pen pen, double spacing, float arrowSize)
         {
             var dx = end.X - start.X;
             var dy = end.Y - start.Y;
@@ -593,12 +592,12 @@ namespace OpenNest.Controls
                 var pt = new Vector(start.X + dirX * t, start.Y + dirY * t);
                 var screenPt = view.PointWorldToGraph(pt);
                 var angle = System.Math.Atan2(-dirY, dirX);
-                DrawArrowHead(g, brush, screenPt, angle, arrowSize);
+                DrawArrowHead(g, pen, screenPt, angle, arrowSize);
             }
         }
 
         private void DrawArcDirectionArrows(Graphics g, Vector start, Vector end, Vector center,
-            RotationType rotation, Brush brush, double spacing, float arrowSize)
+            RotationType rotation, Pen pen, double spacing, float arrowSize)
         {
             var radius = center.DistanceTo(start);
             if (radius < Tolerance.Epsilon) return;
@@ -644,11 +643,11 @@ namespace OpenNest.Controls
                     tangent = angle - System.Math.PI / 2;
 
                 var screenAngle = System.Math.Atan2(-System.Math.Sin(tangent), System.Math.Cos(tangent));
-                DrawArrowHead(g, brush, screenPt, screenAngle, arrowSize);
+                DrawArrowHead(g, pen, screenPt, screenAngle, arrowSize);
             }
         }
 
-        private static void DrawArrowHead(Graphics g, Brush brush, PointF tip, double angle, float size)
+        private static void DrawArrowHead(Graphics g, Pen pen, PointF tip, double angle, float size)
         {
             var sin = (float)System.Math.Sin(angle);
             var cos = (float)System.Math.Cos(angle);
@@ -658,14 +657,11 @@ namespace OpenNest.Controls
             var wingX = size * 0.5f * sin;
             var wingY = -size * 0.5f * cos;
 
-            var points = new PointF[]
-            {
-                tip,
-                new PointF(tip.X + backX + wingX, tip.Y + backY + wingY),
-                new PointF(tip.X + backX - wingX, tip.Y + backY - wingY),
-            };
+            var wing1 = new PointF(tip.X + backX + wingX, tip.Y + backY + wingY);
+            var wing2 = new PointF(tip.X + backX - wingX, tip.Y + backY - wingY);
 
-            g.FillPolygon(brush, points);
+            g.DrawLine(pen, wing1, tip);
+            g.DrawLine(pen, wing2, tip);
         }
 
         private void DrawLine(Graphics g, Vector pt1, Vector pt2, Pen pen)

OpenNest/Forms/MainForm.cs

@@ -1040,6 +1040,13 @@ namespace OpenNest.Forms
             if (postProcessor == null)
                 return;
 
+            if (postProcessor is IConfigurablePostProcessor configurable)
+            {
+                using var configForm = new PostProcessorConfigForm(configurable);
+                if (configForm.ShowDialog() != DialogResult.OK)
+                    return;
+            }
+
             var dialog = new SaveFileDialog();
             dialog.Filter = "CNC File (*.cnc) | *.cnc";
             dialog.FileName = activeForm.Nest.Name;

OpenNest/Forms/PostProcessorConfigForm.Designer.cs

@@ -0,0 +1,98 @@
+namespace OpenNest.Forms
+{
+    partial class PostProcessorConfigForm
+    {
+        private System.ComponentModel.IContainer components = null;
+
+        protected override void Dispose(bool disposing)
+        {
+            if (disposing && (components != null))
+            {
+                components.Dispose();
+            }
+            base.Dispose(disposing);
+        }
+
+        #region Windows Form Designer generated code
+
+        private void InitializeComponent()
+        {
+            this.propertyGrid = new System.Windows.Forms.PropertyGrid();
+            this.bottomPanel = new OpenNest.Controls.BottomPanel();
+            this.okButton = new System.Windows.Forms.Button();
+            this.cancelButton = new System.Windows.Forms.Button();
+            this.bottomPanel.SuspendLayout();
+            this.SuspendLayout();
+            //
+            // propertyGrid
+            //
+            this.propertyGrid.Dock = System.Windows.Forms.DockStyle.Fill;
+            this.propertyGrid.Location = new System.Drawing.Point(0, 0);
+            this.propertyGrid.Name = "propertyGrid";
+            this.propertyGrid.Size = new System.Drawing.Size(484, 511);
+            this.propertyGrid.TabIndex = 0;
+            this.propertyGrid.ToolbarVisible = true;
+            this.propertyGrid.PropertySort = System.Windows.Forms.PropertySort.Categorized;
+            //
+            // bottomPanel
+            //
+            this.bottomPanel.Controls.Add(this.okButton);
+            this.bottomPanel.Controls.Add(this.cancelButton);
+            this.bottomPanel.Dock = System.Windows.Forms.DockStyle.Bottom;
+            this.bottomPanel.Location = new System.Drawing.Point(0, 511);
+            this.bottomPanel.Name = "bottomPanel";
+            this.bottomPanel.Size = new System.Drawing.Size(484, 50);
+            this.bottomPanel.TabIndex = 1;
+            //
+            // okButton
+            //
+            this.okButton.Anchor = ((System.Windows.Forms.AnchorStyles)((System.Windows.Forms.AnchorStyles.Bottom | System.Windows.Forms.AnchorStyles.Right)));
+            this.okButton.DialogResult = System.Windows.Forms.DialogResult.OK;
+            this.okButton.Location = new System.Drawing.Point(286, 11);
+            this.okButton.Name = "okButton";
+            this.okButton.Size = new System.Drawing.Size(90, 28);
+            this.okButton.TabIndex = 0;
+            this.okButton.Text = "OK";
+            this.okButton.UseVisualStyleBackColor = true;
+            this.okButton.Click += new System.EventHandler(this.okButton_Click);
+            //
+            // cancelButton
+            //
+            this.cancelButton.Anchor = ((System.Windows.Forms.AnchorStyles)((System.Windows.Forms.AnchorStyles.Bottom | System.Windows.Forms.AnchorStyles.Right)));
+            this.cancelButton.DialogResult = System.Windows.Forms.DialogResult.Cancel;
+            this.cancelButton.Location = new System.Drawing.Point(382, 11);
+            this.cancelButton.Name = "cancelButton";
+            this.cancelButton.Size = new System.Drawing.Size(90, 28);
+            this.cancelButton.TabIndex = 1;
+            this.cancelButton.Text = "Cancel";
+            this.cancelButton.UseVisualStyleBackColor = true;
+            this.cancelButton.Click += new System.EventHandler(this.cancelButton_Click);
+            //
+            // PostProcessorConfigForm
+            //
+            this.AcceptButton = this.okButton;
+            this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.None;
+            this.CancelButton = this.cancelButton;
+            this.ClientSize = new System.Drawing.Size(484, 561);
+            this.Controls.Add(this.propertyGrid);
+            this.Controls.Add(this.bottomPanel);
+            this.Font = new System.Drawing.Font("Microsoft Sans Serif", 9.75F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((byte)(0)));
+            this.MaximizeBox = false;
+            this.MinimizeBox = false;
+            this.Name = "PostProcessorConfigForm";
+            this.ShowIcon = false;
+            this.ShowInTaskbar = false;
+            this.StartPosition = System.Windows.Forms.FormStartPosition.CenterParent;
+            this.Text = "Post Processor Settings";
+            this.bottomPanel.ResumeLayout(false);
+            this.ResumeLayout(false);
+        }
+
+        #endregion
+
+        private System.Windows.Forms.PropertyGrid propertyGrid;
+        private Controls.BottomPanel bottomPanel;
+        private System.Windows.Forms.Button okButton;
+        private System.Windows.Forms.Button cancelButton;
+    }
+}

OpenNest/Forms/PostProcessorConfigForm.cs

@@ -0,0 +1,42 @@
+using System;
+using System.Text.Json;
+using System.Windows.Forms;
+
+namespace OpenNest.Forms
+{
+    public partial class PostProcessorConfigForm : Form
+    {
+        private readonly IConfigurablePostProcessor postProcessor;
+        private readonly string configBackup;
+
+        public PostProcessorConfigForm(IConfigurablePostProcessor postProcessor)
+        {
+            InitializeComponent();
+
+            this.postProcessor = postProcessor;
+            this.Text = postProcessor.Name + " Settings";
+
+            // Deep-clone config as JSON backup for cancel/restore
+            configBackup = JsonSerializer.Serialize(postProcessor.Config, postProcessor.Config.GetType());
+
+            propertyGrid.SelectedObject = postProcessor.Config;
+        }
+
+        private void okButton_Click(object sender, EventArgs e)
+        {
+            postProcessor.SaveConfig();
+        }
+
+        private void cancelButton_Click(object sender, EventArgs e)
+        {
+            // Restore config from backup
+            var original = JsonSerializer.Deserialize(configBackup, postProcessor.Config.GetType());
+            var properties = postProcessor.Config.GetType().GetProperties();
+            foreach (var prop in properties)
+            {
+                if (prop.CanWrite)
+                    prop.SetValue(postProcessor.Config, prop.GetValue(original));
+            }
+        }
+    }
+}