fix: show cutting parameters dialog before assigning lead-ins

Auto-assign lead-ins silently reused existing plate parameters with no
way to change them after the first assignment. Now a dialog with the
full CuttingPanel is shown every time, pre-populated with the current
settings, so the user can review and modify before confirming.

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

OpenNest.Api/NestRunner.cs

@@ -25,14 +25,13 @@ public static class NestRunner
 
         // 1. Import DXFs → Drawings
         var drawings = new List<Drawing>();
-        var importer = new DxfImporter();
-
         foreach (var part in request.Parts)
         {
             if (!File.Exists(part.DxfPath))
                 throw new FileNotFoundException($"DXF file not found: {part.DxfPath}", part.DxfPath);
 
-            if (!importer.GetGeometry(part.DxfPath, out var geometry) || geometry.Count == 0)
+            var geometry = Dxf.GetGeometry(part.DxfPath);
+            if (geometry.Count == 0)
                 throw new InvalidOperationException($"Failed to import DXF: {part.DxfPath}");
 
             var normalized = ShapeProfile.NormalizeEntities(geometry);

OpenNest.Console/Program.cs

@@ -241,17 +241,11 @@ static class NestConsole
 
     static Drawing ImportDxf(string path)
     {
-        var importer = new DxfImporter();
-
-        if (!importer.GetGeometry(path, out var geometry))
-        {
-            Console.Error.WriteLine($"Error: failed to read DXF file: {path}");
-            return null;
-        }
+        var geometry = Dxf.GetGeometry(path);
 
         if (geometry.Count == 0)
         {
-            Console.Error.WriteLine($"Error: no geometry found in DXF file: {path}");
+            Console.Error.WriteLine($"Error: failed to read DXF file or no geometry found: {path}");
             return null;
         }
 

OpenNest.Core/CNC/CuttingStrategy/ContourCuttingStrategy.cs

@@ -309,7 +309,12 @@ namespace OpenNest.CNC.CuttingStrategy
             if (shape.Entities.Count == 1 && shape.Entities[0] is Circle circle)
                 return circle.Rotation;
 
-            return shape.ToPolygon().RotationDirection();
+            var polygon = shape.ToPolygon();
+
+            if (polygon.Vertices.Count < 3)
+                return RotationType.CCW;
+
+            return polygon.RotationDirection();
         }
 
         private LeadIn ClampLeadInForCircle(LeadIn leadIn, Circle circle, Vector contourPoint, double normalAngle)

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

@@ -1,16 +0,0 @@
-using OpenNest.Geometry;
-using System.Collections.Generic;
-
-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/Converters/ConvertGeometry.cs

@@ -97,7 +97,7 @@ namespace OpenNest.Converters
             if (startpt != lastpt)
                 pgm.MoveTo(startpt);
 
-            pgm.ArcTo(startpt, circle.Center, RotationType.CCW);
+            pgm.ArcTo(startpt, circle.Center, circle.Rotation);
 
             lastpt = startpt;
             return lastpt;

OpenNest.Core/Converters/ConvertProgram.cs

@@ -106,7 +106,7 @@ namespace OpenNest.Converters
             var layer = ConvertLayer(arcMove.Layer);
 
             if (startAngle.IsEqualTo(endAngle))
-                geometry.Add(new Circle(center, radius) { Layer = layer, Color = layer.Color });
+                geometry.Add(new Circle(center, radius) { Layer = layer, Color = layer.Color, Rotation = arcMove.Rotation });
             else
                 geometry.Add(new Arc(center, radius, startAngle, endAngle, arcMove.Rotation == RotationType.CW) { Layer = layer, Color = layer.Color });
 

OpenNest.Core/Drawing.cs

@@ -2,6 +2,7 @@
 using OpenNest.CNC;
 using OpenNest.Converters;
 using OpenNest.Geometry;
+using System;
 using System.Collections.Generic;
 using System.Drawing;
 using System.Linq;
@@ -90,6 +91,18 @@ namespace OpenNest
 
         public List<Bend> Bends { get; set; } = new List<Bend>();
 
+        /// <summary>
+        /// Complete set of source entities with stable GUIDs.
+        /// Null when the drawing was created from G-code or an older nest file.
+        /// </summary>
+        public List<Entity> SourceEntities { get; set; }
+
+        /// <summary>
+        /// IDs of entities in <see cref="SourceEntities"/> that are suppressed (hidden).
+        /// Suppressed entities are excluded from the active Program but preserved for re-enabling.
+        /// </summary>
+        public HashSet<Guid> SuppressedEntityIds { get; set; } = new HashSet<Guid>();
+
         public double Area { get; protected set; }
 
         public void UpdateArea()

OpenNest.Core/Geometry/Circle.cs

@@ -137,7 +137,9 @@ namespace OpenNest.Geometry
         public List<Vector> ToPoints(int segments = 1000, bool circumscribe = false)
         {
             var points = new List<Vector>();
-            var stepAngle = Angle.TwoPI / segments;
+            var stepAngle = Rotation == RotationType.CW
+                ? -Angle.TwoPI / segments
+                : Angle.TwoPI / segments;
 
             var r = circumscribe && segments > 0
                 ? Radius / System.Math.Cos(stepAngle / 2.0)

OpenNest.Core/Geometry/Entity.cs

@@ -1,4 +1,5 @@
 using OpenNest.Math;
+using System;
 using System.Collections.Generic;
 using System.Drawing;
 
@@ -10,10 +11,16 @@ namespace OpenNest.Geometry
 
         protected Entity()
         {
+            Id = Guid.NewGuid();
             Layer = OpenNest.Geometry.Layer.Default;
             boundingBox = new Box();
         }
 
+        /// <summary>
+        /// Unique identifier for this entity, stable across edit sessions.
+        /// </summary>
+        public Guid Id { get; set; }
+
         /// <summary>
         /// Entity color (resolved from DXF ByLayer/ByBlock to actual color).
         /// </summary>

OpenNest.Core/Geometry/Shape.cs

@@ -605,7 +605,7 @@ namespace OpenNest.Geometry
                         copy.Entities.Add(new Arc(a.Center, a.Radius, a.EndAngle, a.StartAngle, !a.IsReversed) { Layer = a.Layer });
                         break;
                     case Circle c:
-                        copy.Entities.Add(new Circle(c.Center, c.Radius) { Layer = c.Layer });
+                        copy.Entities.Add(new Circle(c.Center, c.Radius) { Layer = c.Layer, Rotation = RotationType.CW });
                         break;
                 }
             }
@@ -640,7 +640,7 @@ namespace OpenNest.Geometry
                         copy.Entities.Add(new Arc(a.Center, a.Radius, a.EndAngle, a.StartAngle, !a.IsReversed) { Layer = a.Layer });
                         break;
                     case Circle c:
-                        copy.Entities.Add(new Circle(c.Center, c.Radius) { Layer = c.Layer });
+                        copy.Entities.Add(new Circle(c.Center, c.Radius) { Layer = c.Layer, Rotation = RotationType.CCW });
                         break;
                 }
             }

OpenNest.Core/Geometry/SpatialQuery.cs

@@ -104,6 +104,98 @@ namespace OpenNest.Geometry
             return double.MaxValue;
         }
 
+        /// <summary>
+        /// Solves ray-circle intersection, returning the two parametric t values.
+        /// Returns false if no real intersection exists.
+        /// </summary>
+        [System.Runtime.CompilerServices.MethodImpl(
+            System.Runtime.CompilerServices.MethodImplOptions.AggressiveInlining)]
+        private static bool SolveRayCircle(
+            double vx, double vy,
+            double cx, double cy, double r,
+            double dirX, double dirY,
+            out double t1, out double t2)
+        {
+            var ox = vx - cx;
+            var oy = vy - cy;
+
+            var a = dirX * dirX + dirY * dirY;
+            var b = 2.0 * (ox * dirX + oy * dirY);
+            var c = ox * ox + oy * oy - r * r;
+
+            var discriminant = b * b - 4.0 * a * c;
+            if (discriminant < 0)
+            {
+                t1 = t2 = double.MaxValue;
+                return false;
+            }
+
+            var sqrtD = System.Math.Sqrt(discriminant);
+            var inv2a = 1.0 / (2.0 * a);
+            t1 = (-b - sqrtD) * inv2a;
+            t2 = (-b + sqrtD) * inv2a;
+            return true;
+        }
+
+        /// <summary>
+        /// Computes the distance from a point along a direction to an arc.
+        /// Solves ray-circle intersection, then constrains hits to the arc's
+        /// angular span. Returns double.MaxValue if no hit.
+        /// </summary>
+        [System.Runtime.CompilerServices.MethodImpl(
+            System.Runtime.CompilerServices.MethodImplOptions.AggressiveInlining)]
+        public static double RayArcDistance(
+            double vx, double vy,
+            double cx, double cy, double r,
+            double startAngle, double endAngle, bool reversed,
+            double dirX, double dirY)
+        {
+            if (!SolveRayCircle(vx, vy, cx, cy, r, dirX, dirY, out var t1, out var t2))
+                return double.MaxValue;
+
+            var best = double.MaxValue;
+
+            if (t1 > -Tolerance.Epsilon)
+            {
+                var hitAngle = Angle.NormalizeRad(System.Math.Atan2(
+                    vy + t1 * dirY - cy, vx + t1 * dirX - cx));
+                if (Angle.IsBetweenRad(hitAngle, startAngle, endAngle, reversed))
+                    best = t1 > Tolerance.Epsilon ? t1 : 0;
+            }
+
+            if (t2 > -Tolerance.Epsilon && t2 < best)
+            {
+                var hitAngle = Angle.NormalizeRad(System.Math.Atan2(
+                    vy + t2 * dirY - cy, vx + t2 * dirX - cx));
+                if (Angle.IsBetweenRad(hitAngle, startAngle, endAngle, reversed))
+                    best = t2 > Tolerance.Epsilon ? t2 : 0;
+            }
+
+            return best;
+        }
+
+        /// <summary>
+        /// Computes the distance from a point along a direction to a full circle.
+        /// Returns double.MaxValue if no hit.
+        /// </summary>
+        [System.Runtime.CompilerServices.MethodImpl(
+            System.Runtime.CompilerServices.MethodImplOptions.AggressiveInlining)]
+        public static double RayCircleDistance(
+            double vx, double vy,
+            double cx, double cy, double r,
+            double dirX, double dirY)
+        {
+            if (!SolveRayCircle(vx, vy, cx, cy, r, dirX, dirY, out var t1, out var t2))
+                return double.MaxValue;
+
+            if (t1 > Tolerance.Epsilon) return t1;
+            if (t1 >= -Tolerance.Epsilon) return 0;
+            if (t2 > Tolerance.Epsilon) return t2;
+            if (t2 >= -Tolerance.Epsilon) return 0;
+
+            return double.MaxValue;
+        }
+
         /// <summary>
         /// Computes the minimum translation distance along a push direction before
         /// any edge of movingLines contacts any edge of stationaryLines.
@@ -111,57 +203,7 @@ namespace OpenNest.Geometry
         /// </summary>
         public static double DirectionalDistance(List<Line> movingLines, List<Line> stationaryLines, PushDirection direction)
         {
-            var minDist = double.MaxValue;
-
-            // Case 1: Each moving vertex -> each stationary edge
-            var movingVertices = new HashSet<Vector>();
-            for (int i = 0; i < movingLines.Count; i++)
-            {
-                movingVertices.Add(movingLines[i].pt1);
-                movingVertices.Add(movingLines[i].pt2);
-            }
-
-            var stationaryEdges = new (Vector start, Vector end)[stationaryLines.Count];
-            for (int i = 0; i < stationaryLines.Count; i++)
-                stationaryEdges[i] = (stationaryLines[i].pt1, stationaryLines[i].pt2);
-
-            // Sort edges for pruning if not already sorted (usually they aren't here)
-            if (direction == PushDirection.Left || direction == PushDirection.Right)
-                stationaryEdges = stationaryEdges.OrderBy(e => System.Math.Min(e.start.Y, e.end.Y)).ToArray();
-            else
-                stationaryEdges = stationaryEdges.OrderBy(e => System.Math.Min(e.start.X, e.end.X)).ToArray();
-
-            foreach (var mv in movingVertices)
-            {
-                var d = OneWayDistance(mv, stationaryEdges, Vector.Zero, direction);
-                if (d < minDist) minDist = d;
-            }
-
-            // Case 2: Each stationary vertex -> each moving edge (opposite direction)
-            var opposite = OppositeDirection(direction);
-            var stationaryVertices = new HashSet<Vector>();
-            for (int i = 0; i < stationaryLines.Count; i++)
-            {
-                stationaryVertices.Add(stationaryLines[i].pt1);
-                stationaryVertices.Add(stationaryLines[i].pt2);
-            }
-
-            var movingEdges = new (Vector start, Vector end)[movingLines.Count];
-            for (int i = 0; i < movingLines.Count; i++)
-                movingEdges[i] = (movingLines[i].pt1, movingLines[i].pt2);
-
-            if (opposite == PushDirection.Left || opposite == PushDirection.Right)
-                movingEdges = movingEdges.OrderBy(e => System.Math.Min(e.start.Y, e.end.Y)).ToArray();
-            else
-                movingEdges = movingEdges.OrderBy(e => System.Math.Min(e.start.X, e.end.X)).ToArray();
-
-            foreach (var sv in stationaryVertices)
-            {
-                var d = OneWayDistance(sv, movingEdges, Vector.Zero, opposite);
-                if (d < minDist) minDist = d;
-            }
-
-            return minDist;
+            return DirectionalDistance(movingLines, 0, 0, stationaryLines, direction);
         }
 
         /// <summary>
@@ -176,21 +218,10 @@ namespace OpenNest.Geometry
             var movingOffset = new Vector(movingDx, movingDy);
 
             // Case 1: Each moving vertex -> each stationary edge
-            var movingVertices = new HashSet<Vector>();
-            for (int i = 0; i < movingLines.Count; i++)
-            {
-                movingVertices.Add(movingLines[i].pt1 + movingOffset);
-                movingVertices.Add(movingLines[i].pt2 + movingOffset);
-            }
+            var movingVertices = CollectVertices(movingLines, movingOffset);
 
-            var stationaryEdges = new (Vector start, Vector end)[stationaryLines.Count];
-            for (int i = 0; i < stationaryLines.Count; i++)
-                stationaryEdges[i] = (stationaryLines[i].pt1, stationaryLines[i].pt2);
-
-            if (direction == PushDirection.Left || direction == PushDirection.Right)
-                stationaryEdges = stationaryEdges.OrderBy(e => System.Math.Min(e.start.Y, e.end.Y)).ToArray();
-            else
-                stationaryEdges = stationaryEdges.OrderBy(e => System.Math.Min(e.start.X, e.end.X)).ToArray();
+            var stationaryEdges = ToEdgeArray(stationaryLines);
+            SortEdgesForPruning(stationaryEdges, direction);
 
             foreach (var mv in movingVertices)
             {
@@ -200,21 +231,10 @@ namespace OpenNest.Geometry
 
             // Case 2: Each stationary vertex -> each moving edge (opposite direction)
             var opposite = OppositeDirection(direction);
-            var stationaryVertices = new HashSet<Vector>();
-            for (int i = 0; i < stationaryLines.Count; i++)
-            {
-                stationaryVertices.Add(stationaryLines[i].pt1);
-                stationaryVertices.Add(stationaryLines[i].pt2);
-            }
+            var stationaryVertices = CollectVertices(stationaryLines, Vector.Zero);
 
-            var movingEdges = new (Vector start, Vector end)[movingLines.Count];
-            for (int i = 0; i < movingLines.Count; i++)
-                movingEdges[i] = (movingLines[i].pt1, movingLines[i].pt2);
-
-            if (opposite == PushDirection.Left || opposite == PushDirection.Right)
-                movingEdges = movingEdges.OrderBy(e => System.Math.Min(e.start.Y, e.end.Y)).ToArray();
-            else
-                movingEdges = movingEdges.OrderBy(e => System.Math.Min(e.start.X, e.end.X)).ToArray();
+            var movingEdges = ToEdgeArray(movingLines);
+            SortEdgesForPruning(movingEdges, opposite);
 
             foreach (var sv in stationaryVertices)
             {
@@ -253,15 +273,11 @@ namespace OpenNest.Geometry
         {
             var minDist = double.MaxValue;
 
-            // Extract unique vertices from moving edges.
-            var movingVertices = new HashSet<Vector>();
-            for (var i = 0; i < movingEdges.Length; i++)
-            {
-                movingVertices.Add(movingEdges[i].start + movingOffset);
-                movingVertices.Add(movingEdges[i].end + movingOffset);
-            }
+            SortEdgesForPruning(stationaryEdges, direction);
 
             // Case 1: Each moving vertex -> each stationary edge
+            var movingVertices = CollectVertices(movingEdges, movingOffset);
+
             foreach (var mv in movingVertices)
             {
                 var d = OneWayDistance(mv, stationaryEdges, stationaryOffset, direction);
@@ -270,12 +286,9 @@ namespace OpenNest.Geometry
 
             // Case 2: Each stationary vertex -> each moving edge (opposite direction)
             var opposite = OppositeDirection(direction);
-            var stationaryVertices = new HashSet<Vector>();
-            for (var i = 0; i < stationaryEdges.Length; i++)
-            {
-                stationaryVertices.Add(stationaryEdges[i].start + stationaryOffset);
-                stationaryVertices.Add(stationaryEdges[i].end + stationaryOffset);
-            }
+            SortEdgesForPruning(movingEdges, opposite);
+
+            var stationaryVertices = CollectVertices(stationaryEdges, stationaryOffset);
 
             foreach (var sv in stationaryVertices)
             {
@@ -467,12 +480,7 @@ namespace OpenNest.Geometry
             var dirX = direction.X;
             var dirY = direction.Y;
 
-            var movingVertices = new HashSet<Vector>();
-            for (var i = 0; i < movingLines.Count; i++)
-            {
-                movingVertices.Add(movingLines[i].pt1);
-                movingVertices.Add(movingLines[i].pt2);
-            }
+            var movingVertices = CollectVertices(movingLines, Vector.Zero);
 
             foreach (var mv in movingVertices)
             {
@@ -487,12 +495,7 @@ namespace OpenNest.Geometry
             var oppX = -dirX;
             var oppY = -dirY;
 
-            var stationaryVertices = new HashSet<Vector>();
-            for (var i = 0; i < stationaryLines.Count; i++)
-            {
-                stationaryVertices.Add(stationaryLines[i].pt1);
-                stationaryVertices.Add(stationaryLines[i].pt2);
-            }
+            var stationaryVertices = CollectVertices(stationaryLines, Vector.Zero);
 
             foreach (var sv in stationaryVertices)
             {
@@ -507,6 +510,284 @@ namespace OpenNest.Geometry
             return minDist;
         }
 
+        /// <summary>
+        /// Computes the minimum translation distance along a push direction
+        /// before any vertex/edge of movingEntities contacts any vertex/edge of
+        /// stationaryEntities. Delegates to the Vector-based overload.
+        /// </summary>
+        public static double DirectionalDistance(
+            List<Entity> movingEntities, List<Entity> stationaryEntities, PushDirection direction)
+        {
+            return DirectionalDistance(movingEntities, stationaryEntities, DirectionToOffset(direction, 1.0));
+        }
+
+        /// <summary>
+        /// Computes the minimum translation distance along an arbitrary unit direction
+        /// before any vertex/edge of movingEntities contacts any vertex/edge of
+        /// stationaryEntities. Works with native Line, Arc, and Circle entities
+        /// without tessellation.
+        /// </summary>
+        public static double DirectionalDistance(
+            List<Entity> movingEntities, List<Entity> stationaryEntities, Vector direction)
+        {
+            var minDist = double.MaxValue;
+            var dirX = direction.X;
+            var dirY = direction.Y;
+
+            var movingVertices = ExtractEntityVertices(movingEntities);
+
+            for (var v = 0; v < movingVertices.Length; v++)
+            {
+                var vx = movingVertices[v].X;
+                var vy = movingVertices[v].Y;
+
+                for (var j = 0; j < stationaryEntities.Count; j++)
+                {
+                    var d = RayEntityDistance(vx, vy, stationaryEntities[j], dirX, dirY);
+                    if (d < minDist)
+                    {
+                        minDist = d;
+                        if (d <= 0) return 0;
+                    }
+                }
+            }
+
+            var oppX = -dirX;
+            var oppY = -dirY;
+
+            var stationaryVertices = ExtractEntityVertices(stationaryEntities);
+
+            for (var v = 0; v < stationaryVertices.Length; v++)
+            {
+                var vx = stationaryVertices[v].X;
+                var vy = stationaryVertices[v].Y;
+
+                for (var j = 0; j < movingEntities.Count; j++)
+                {
+                    var d = RayEntityDistance(vx, vy, movingEntities[j], oppX, oppY);
+                    if (d < minDist)
+                    {
+                        minDist = d;
+                        if (d <= 0) return 0;
+                    }
+                }
+            }
+
+            // Phase 3: Arc-to-line closest-point check.
+            // Phases 1-2 sample arc endpoints and cardinal extremes, but the actual
+            // closest point on a small corner arc to a straight edge may lie between
+            // those samples. Use ClosestPointTo to find it and fire a ray from there.
+            minDist = ArcToLineClosestDistance(movingEntities, stationaryEntities, dirX, dirY, minDist);
+            if (minDist <= 0) return 0;
+            minDist = ArcToLineClosestDistance(stationaryEntities, movingEntities, oppX, oppY, minDist);
+            if (minDist <= 0) return 0;
+
+            // Phase 4: Curve-to-curve direct distance.
+            // The vertex-to-entity approach misses the closest contact between two
+            // curved entities (circles/arcs) because only a few cardinal vertices are
+            // sampled. The true closest contact along the push direction is found by
+            // treating it as a ray from one center to an expanded circle at the other
+            // center (radius = r1 + r2).
+            for (var i = 0; i < movingEntities.Count; i++)
+            {
+                var me = movingEntities[i];
+                if (!TryGetCurveParams(me, out var mcx, out var mcy, out var mr))
+                    continue;
+
+                for (var j = 0; j < stationaryEntities.Count; j++)
+                {
+                    var se = stationaryEntities[j];
+                    if (!TryGetCurveParams(se, out var scx, out var scy, out var sr))
+                        continue;
+
+                    var d = RayCircleDistance(mcx, mcy, scx, scy, mr + sr, dirX, dirY);
+
+                    if (d >= minDist)
+                        continue;
+
+                    // For arcs, verify the contact point falls within both arcs' angular ranges.
+                    if (me is Arc || se is Arc)
+                    {
+                        var mx = mcx + d * dirX;
+                        var my = mcy + d * dirY;
+                        var toCx = scx - mx;
+                        var toCy = scy - my;
+
+                        if (me is Arc mArc)
+                        {
+                            var angle = Angle.NormalizeRad(System.Math.Atan2(toCy, toCx));
+                            if (!Angle.IsBetweenRad(angle, mArc.StartAngle, mArc.EndAngle, mArc.IsReversed))
+                                continue;
+                        }
+
+                        if (se is Arc sArc)
+                        {
+                            var angle = Angle.NormalizeRad(System.Math.Atan2(-toCy, -toCx));
+                            if (!Angle.IsBetweenRad(angle, sArc.StartAngle, sArc.EndAngle, sArc.IsReversed))
+                                continue;
+                        }
+                    }
+
+                    minDist = d;
+                    if (d <= 0) return 0;
+                }
+            }
+
+            return minDist;
+        }
+
+        private static double ArcToLineClosestDistance(
+            List<Entity> arcEntities, List<Entity> lineEntities,
+            double dirX, double dirY, double minDist)
+        {
+            for (var i = 0; i < arcEntities.Count; i++)
+            {
+                if (arcEntities[i] is Arc arc)
+                {
+                    for (var j = 0; j < lineEntities.Count; j++)
+                    {
+                        if (lineEntities[j] is Line line)
+                        {
+                            var linePt = line.ClosestPointTo(arc.Center);
+                            var arcPt = arc.ClosestPointTo(linePt);
+                            var d = RayEdgeDistance(arcPt.X, arcPt.Y,
+                                line.pt1.X, line.pt1.Y, line.pt2.X, line.pt2.Y,
+                                dirX, dirY);
+                            if (d < minDist) { minDist = d; if (d <= 0) return 0; }
+                        }
+                    }
+                }
+            }
+            return minDist;
+        }
+
+        private static double RayEntityDistance(
+            double vx, double vy, Entity entity, double dirX, double dirY)
+        {
+            if (entity is Line line)
+            {
+                return RayEdgeDistance(vx, vy,
+                    line.pt1.X, line.pt1.Y, line.pt2.X, line.pt2.Y,
+                    dirX, dirY);
+            }
+
+            if (entity is Arc arc)
+            {
+                return RayArcDistance(vx, vy,
+                    arc.Center.X, arc.Center.Y, arc.Radius,
+                    arc.StartAngle, arc.EndAngle, arc.IsReversed,
+                    dirX, dirY);
+            }
+
+            if (entity is Circle circle)
+            {
+                return RayCircleDistance(vx, vy,
+                    circle.Center.X, circle.Center.Y, circle.Radius,
+                    dirX, dirY);
+            }
+
+            return double.MaxValue;
+        }
+
+        private static Vector[] ExtractEntityVertices(List<Entity> entities)
+        {
+            var vertices = new HashSet<Vector>();
+
+            for (var i = 0; i < entities.Count; i++)
+            {
+                var entity = entities[i];
+
+                if (entity is Line line)
+                {
+                    vertices.Add(line.pt1);
+                    vertices.Add(line.pt2);
+                }
+                else if (entity is Arc arc)
+                {
+                    vertices.Add(arc.StartPoint());
+                    vertices.Add(arc.EndPoint());
+                    AddArcExtremeVertices(vertices, arc);
+                }
+                else if (entity is Circle circle)
+                {
+                    vertices.Add(new Vector(circle.Center.X + circle.Radius, circle.Center.Y));
+                    vertices.Add(new Vector(circle.Center.X - circle.Radius, circle.Center.Y));
+                    vertices.Add(new Vector(circle.Center.X, circle.Center.Y + circle.Radius));
+                    vertices.Add(new Vector(circle.Center.X, circle.Center.Y - circle.Radius));
+                }
+            }
+
+            return vertices.ToArray();
+        }
+
+        private static void AddArcExtremeVertices(HashSet<Vector> points, Arc arc)
+        {
+            var a1 = arc.StartAngle;
+            var a2 = arc.EndAngle;
+
+            if (arc.IsReversed)
+                Generic.Swap(ref a1, ref a2);
+
+            if (Angle.IsBetweenRad(Angle.TwoPI, a1, a2))
+                points.Add(new Vector(arc.Center.X + arc.Radius, arc.Center.Y));
+            if (Angle.IsBetweenRad(Angle.HalfPI, a1, a2))
+                points.Add(new Vector(arc.Center.X, arc.Center.Y + arc.Radius));
+            if (Angle.IsBetweenRad(System.Math.PI, a1, a2))
+                points.Add(new Vector(arc.Center.X - arc.Radius, arc.Center.Y));
+            if (Angle.IsBetweenRad(System.Math.PI * 1.5, a1, a2))
+                points.Add(new Vector(arc.Center.X, arc.Center.Y - arc.Radius));
+        }
+
+        private static HashSet<Vector> CollectVertices(List<Line> lines, Vector offset)
+        {
+            return CollectVertices(ToEdgeArray(lines), offset);
+        }
+
+        private static HashSet<Vector> CollectVertices((Vector start, Vector end)[] edges, Vector offset)
+        {
+            var vertices = new HashSet<Vector>();
+            for (var i = 0; i < edges.Length; i++)
+            {
+                vertices.Add(edges[i].start + offset);
+                vertices.Add(edges[i].end + offset);
+            }
+            return vertices;
+        }
+
+        private static (Vector start, Vector end)[] ToEdgeArray(List<Line> lines)
+        {
+            var edges = new (Vector start, Vector end)[lines.Count];
+            for (var i = 0; i < lines.Count; i++)
+                edges[i] = (lines[i].pt1, lines[i].pt2);
+            return edges;
+        }
+
+        private static void SortEdgesForPruning((Vector start, Vector end)[] edges, PushDirection direction)
+        {
+            if (direction == PushDirection.Left || direction == PushDirection.Right)
+                System.Array.Sort(edges, (a, b) =>
+                    System.Math.Min(a.start.Y, a.end.Y).CompareTo(System.Math.Min(b.start.Y, b.end.Y)));
+            else
+                System.Array.Sort(edges, (a, b) =>
+                    System.Math.Min(a.start.X, a.end.X).CompareTo(System.Math.Min(b.start.X, b.end.X)));
+        }
+
+        private static bool TryGetCurveParams(Entity entity, out double cx, out double cy, out double r)
+        {
+            if (entity is Circle circle)
+            {
+                cx = circle.Center.X; cy = circle.Center.Y; r = circle.Radius;
+                return true;
+            }
+            if (entity is Arc arc)
+            {
+                cx = arc.Center.X; cy = arc.Center.Y; r = arc.Radius;
+                return true;
+            }
+            cx = cy = r = 0;
+            return false;
+        }
+
         private static double BoxProjectionMin(Box box, double dx, double dy)
         {
             var x = dx >= 0 ? box.Left : box.Right;

OpenNest.Core/Part.cs

@@ -190,7 +190,14 @@ namespace OpenNest
         {
             var rotation = Rotation;
             Program = BaseDrawing.Program.Clone() as Program;
-            Program.Rotate(Program.Rotation - rotation);
+
+            if (!Math.Tolerance.IsEqualTo(rotation, 0))
+                Program.Rotate(rotation);
+
+            HasManualLeadIns = false;
+            LeadInsLocked = false;
+            CuttingParameters = null;
+            UpdateBounds();
         }
 
         /// <summary>

OpenNest.Core/PartGeometry.cs

@@ -39,7 +39,115 @@ namespace OpenNest
             return lines;
         }
 
-        public static List<Line> GetOffsetPartLines(Part part, double spacing, double chordTolerance = 0.001)
+        /// <summary>
+        /// Returns the perimeter entities (Line, Arc, Circle) with spacing offset applied,
+        /// without tessellation. Much faster than GetOffsetPartLines for parts with many arcs.
+        /// </summary>
+        public static List<Entity> GetOffsetPerimeterEntities(Part part, double spacing)
+        {
+            var geoEntities = ConvertProgram.ToGeometry(part.Program);
+            var profile = new ShapeProfile(
+                geoEntities.Where(e => e.Layer != SpecialLayers.Rapid).ToList());
+
+            var offsetShape = profile.Perimeter.OffsetOutward(spacing);
+            if (offsetShape == null)
+                return new List<Entity>();
+
+            // Offset the shape's entities to the part's location.
+            // OffsetOutward creates a new Shape, so mutating is safe.
+            foreach (var entity in offsetShape.Entities)
+                entity.Offset(part.Location);
+
+            return offsetShape.Entities;
+        }
+
+        /// <summary>
+        /// Returns all entities (perimeter + cutouts) with spacing offset applied,
+        /// without tessellation. Perimeter is offset outward, cutouts inward.
+        /// </summary>
+        public static List<Entity> GetOffsetPartEntities(Part part, double spacing)
+        {
+            var geoEntities = ConvertProgram.ToGeometry(part.Program);
+            var profile = new ShapeProfile(
+                geoEntities.Where(e => e.Layer != SpecialLayers.Rapid).ToList());
+            var entities = new List<Entity>();
+
+            var perimeter = profile.Perimeter.OffsetOutward(spacing);
+            if (perimeter != null)
+            {
+                foreach (var entity in perimeter.Entities)
+                    entity.Offset(part.Location);
+                entities.AddRange(perimeter.Entities);
+            }
+
+            foreach (var cutout in profile.Cutouts)
+            {
+                var inset = cutout.OffsetInward(spacing);
+                if (inset == null) continue;
+                foreach (var entity in inset.Entities)
+                    entity.Offset(part.Location);
+                entities.AddRange(inset.Entities);
+            }
+
+            return entities;
+        }
+
+        /// <summary>
+        /// Returns perimeter entities at the part's world location, without tessellation
+        /// or spacing offset.
+        /// </summary>
+        public static List<Entity> GetPerimeterEntities(Part part)
+        {
+            var geoEntities = ConvertProgram.ToGeometry(part.Program);
+            var profile = new ShapeProfile(
+                geoEntities.Where(e => e.Layer != SpecialLayers.Rapid).ToList());
+
+            return CopyEntitiesAtLocation(profile.Perimeter.Entities, part.Location);
+        }
+
+        /// <summary>
+        /// Returns all entities (perimeter + cutouts) at the part's world location,
+        /// without tessellation or spacing offset.
+        /// </summary>
+        public static List<Entity> GetPartEntities(Part part)
+        {
+            var geoEntities = ConvertProgram.ToGeometry(part.Program);
+            var profile = new ShapeProfile(
+                geoEntities.Where(e => e.Layer != SpecialLayers.Rapid).ToList());
+            var entities = CopyEntitiesAtLocation(profile.Perimeter.Entities, part.Location);
+
+            foreach (var cutout in profile.Cutouts)
+                entities.AddRange(CopyEntitiesAtLocation(cutout.Entities, part.Location));
+
+            return entities;
+        }
+
+        private static List<Entity> CopyEntitiesAtLocation(List<Entity> source, Vector location)
+        {
+            var result = new List<Entity>(source.Count);
+
+            for (var i = 0; i < source.Count; i++)
+            {
+                var entity = source[i];
+                Entity copy;
+
+                if (entity is Line line)
+                    copy = new Line(line.StartPoint + location, line.EndPoint + location);
+                else if (entity is Arc arc)
+                    copy = new Arc(arc.Center + location, arc.Radius, arc.StartAngle, arc.EndAngle, arc.IsReversed);
+                else if (entity is Circle circle)
+                    copy = new Circle(circle.Center + location, circle.Radius);
+                else
+                    continue;
+
+                result.Add(copy);
+            }
+
+            return result;
+        }
+
+        public static List<Line> GetOffsetPartLines(Part part, double spacing, double chordTolerance = 0.001,
+            bool perimeterOnly = false)
         {
             var entities = ConvertProgram.ToGeometry(part.Program);
             var profile = new ShapeProfile(
@@ -50,9 +158,12 @@ namespace OpenNest
             AddOffsetLines(lines, profile.Perimeter.OffsetOutward(totalSpacing),
                 chordTolerance, part.Location);
 
-            foreach (var cutout in profile.Cutouts)
-                AddOffsetLines(lines, cutout.OffsetInward(totalSpacing),
-                    chordTolerance, part.Location);
+            if (!perimeterOnly)
+            {
+                foreach (var cutout in profile.Cutouts)
+                    AddOffsetLines(lines, cutout.OffsetInward(totalSpacing),
+                        chordTolerance, part.Location);
+            }
 
             return lines;
         }

OpenNest.Core/Shapes/CircleShape.cs

@@ -7,6 +7,11 @@ namespace OpenNest.Shapes
     {
         public double Diameter { get; set; }
 
+        public override void SetPreviewDefaults()
+        {
+            Diameter = 8;
+        }
+
         public override Drawing GetDrawing()
         {
             var entities = new List<Entity>

OpenNest.Core/Shapes/FlangeShape.cs

@@ -11,6 +11,15 @@ namespace OpenNest.Shapes
         public double HolePatternDiameter { get; set; }
         public int HoleCount { get; set; }
 
+        public override void SetPreviewDefaults()
+        {
+            NominalPipeSize = 2;
+            OD = 7.5;
+            HoleDiameter = 0.875;
+            HolePatternDiameter = 5.5;
+            HoleCount = 8;
+        }
+
         public override Drawing GetDrawing()
         {
             var entities = new List<Entity>();

OpenNest.Core/Shapes/IsoscelesTriangleShape.cs

@@ -8,6 +8,12 @@ namespace OpenNest.Shapes
         public double Base { get; set; }
         public double Height { get; set; }
 
+        public override void SetPreviewDefaults()
+        {
+            Base = 8;
+            Height = 10;
+        }
+
         public override Drawing GetDrawing()
         {
             var midX = Base / 2.0;

OpenNest.Core/Shapes/LShape.cs

@@ -10,6 +10,14 @@ namespace OpenNest.Shapes
         public double LegWidth { get; set; }
         public double LegHeight { get; set; }
 
+        public override void SetPreviewDefaults()
+        {
+            Width = 8;
+            Height = 10;
+            LegWidth = 3;
+            LegHeight = 3;
+        }
+
         public override Drawing GetDrawing()
         {
             var lw = LegWidth > 0 ? LegWidth : Width / 2.0;

OpenNest.Core/Shapes/OctagonShape.cs

@@ -7,6 +7,11 @@ namespace OpenNest.Shapes
     {
         public double Width { get; set; }
 
+        public override void SetPreviewDefaults()
+        {
+            Width = 8;
+        }
+
         public override Drawing GetDrawing()
         {
             var center = Width / 2.0;

OpenNest.Core/Shapes/RectangleShape.cs

@@ -8,6 +8,12 @@ namespace OpenNest.Shapes
         public double Length { get; set; }
         public double Width { get; set; }
 
+        public override void SetPreviewDefaults()
+        {
+            Length = 12;
+            Width = 6;
+        }
+
         public override Drawing GetDrawing()
         {
             var entities = new List<Entity>

OpenNest.Core/Shapes/RightTriangleShape.cs

@@ -8,6 +8,12 @@ namespace OpenNest.Shapes
         public double Width { get; set; }
         public double Height { get; set; }
 
+        public override void SetPreviewDefaults()
+        {
+            Width = 8;
+            Height = 6;
+        }
+
         public override Drawing GetDrawing()
         {
             var entities = new List<Entity>

OpenNest.Core/Shapes/RingShape.cs

@@ -8,6 +8,12 @@ namespace OpenNest.Shapes
         public double OuterDiameter { get; set; }
         public double InnerDiameter { get; set; }
 
+        public override void SetPreviewDefaults()
+        {
+            OuterDiameter = 10;
+            InnerDiameter = 6;
+        }
+
         public override Drawing GetDrawing()
         {
             var entities = new List<Entity>

OpenNest.Core/Shapes/RoundedRectangleShape.cs

@@ -10,6 +10,13 @@ namespace OpenNest.Shapes
         public double Width { get; set; }
         public double Radius { get; set; }
 
+        public override void SetPreviewDefaults()
+        {
+            Length = 12;
+            Width = 6;
+            Radius = 1;
+        }
+
         public override Drawing GetDrawing()
         {
             var r = Radius;

OpenNest.Core/Shapes/ShapeDefinition.cs

@@ -26,6 +26,8 @@ namespace OpenNest.Shapes
 
         public abstract Drawing GetDrawing();
 
+        public virtual void SetPreviewDefaults() { }
+
         public static List<T> LoadFromJson<T>(string path) where T : ShapeDefinition
         {
             var json = File.ReadAllText(path);

OpenNest.Core/Shapes/TShape.cs

@@ -10,6 +10,14 @@ namespace OpenNest.Shapes
         public double StemWidth { get; set; }
         public double BarHeight { get; set; }
 
+        public override void SetPreviewDefaults()
+        {
+            Width = 10;
+            Height = 8;
+            StemWidth = 3;
+            BarHeight = 3;
+        }
+
         public override Drawing GetDrawing()
         {
             var sw = StemWidth > 0 ? StemWidth : Width / 3.0;

OpenNest.Core/Shapes/TrapezoidShape.cs

@@ -9,6 +9,13 @@ namespace OpenNest.Shapes
         public double BottomWidth { get; set; }
         public double Height { get; set; }
 
+        public override void SetPreviewDefaults()
+        {
+            TopWidth = 6;
+            BottomWidth = 10;
+            Height = 6;
+        }
+
         public override Drawing GetDrawing()
         {
             var offset = (BottomWidth - TopWidth) / 2.0;

OpenNest.Engine/BestFit/BestFitFilter.cs

@@ -17,7 +17,8 @@ namespace OpenNest.Engine.BestFit
                 if (!result.Keep)
                     continue;
 
-                if (result.ShortestSide > System.Math.Min(MaxPlateWidth, MaxPlateHeight))
+                if (result.ShortestSide > System.Math.Min(MaxPlateWidth, MaxPlateHeight) ||
+                    result.LongestSide > System.Math.Max(MaxPlateWidth, MaxPlateHeight))
                 {
                     result.Keep = false;
                     result.Reason = "Exceeds plate dimensions";

OpenNest.Engine/BestFit/BestFitFinder.cs

@@ -4,6 +4,7 @@ using OpenNest.Geometry;
 using OpenNest.Math;
 using System.Collections.Concurrent;
 using System.Collections.Generic;
+using System.Diagnostics;
 using System.Linq;
 using System.Threading.Tasks;
 
@@ -49,6 +50,8 @@ namespace OpenNest.Engine.BestFit
 
             var allCandidates = candidateBags.SelectMany(c => c).ToList();
 
+            Debug.WriteLine($"[BestFitFinder] {strategies.Count} strategies, {allCandidates.Count} candidates");
+
             var results = _evaluator.EvaluateAll(allCandidates);
 
             _filter.Apply(results);

OpenNest.Engine/BestFit/CpuDistanceComputer.cs

@@ -1,4 +1,5 @@
 using OpenNest.Geometry;
+using OpenNest.Math;
 using System.Collections.Generic;
 using System.Linq;
 
@@ -17,7 +18,6 @@ namespace OpenNest.Engine.BestFit
             var allMovingVerts = ExtractUniqueVertices(movingTemplateLines);
             var allStationaryVerts = ExtractUniqueVertices(stationaryLines);
 
-            // Pre-filter vertices per unique direction (typically 4 cardinal directions).
             var vertexCache = new Dictionary<(double, double), (Vector[] leading, Vector[] facing)>();
 
             foreach (var offset in offsets)
@@ -43,7 +43,6 @@ namespace OpenNest.Engine.BestFit
 
                 var minDist = double.MaxValue;
 
-                // Case 1: Leading moving vertices → stationary edges
                 for (var v = 0; v < leadingMoving.Length; v++)
                 {
                     var vx = leadingMoving[v].X + offset.Dx;
@@ -66,7 +65,6 @@ namespace OpenNest.Engine.BestFit
                     }
                 }
 
-                // Case 2: Facing stationary vertices → moving edges (opposite direction)
                 for (var v = 0; v < facingStationary.Length; v++)
                 {
                     var svx = facingStationary[v].X;
@@ -95,6 +93,253 @@ namespace OpenNest.Engine.BestFit
             return results;
         }
 
+        public double[] ComputeDistances(
+            List<Entity> stationaryEntities,
+            List<Entity> movingEntities,
+            SlideOffset[] offsets)
+        {
+            var count = offsets.Length;
+            var results = new double[count];
+
+            var allMovingVerts = ExtractVerticesFromEntities(movingEntities);
+            var allStationaryVerts = ExtractVerticesFromEntities(stationaryEntities);
+
+            var movingCurves = ExtractCurveParams(movingEntities);
+            var stationaryCurves = ExtractCurveParams(stationaryEntities);
+
+            var vertexCache = new Dictionary<(double, double), (Vector[] leading, Vector[] facing)>();
+
+            foreach (var offset in offsets)
+            {
+                var key = (offset.DirX, offset.DirY);
+                if (vertexCache.ContainsKey(key))
+                    continue;
+
+                var leading = FilterVerticesByProjection(allMovingVerts, offset.DirX, offset.DirY, keepHigh: true);
+                var facing = FilterVerticesByProjection(allStationaryVerts, offset.DirX, offset.DirY, keepHigh: false);
+                vertexCache[key] = (leading, facing);
+            }
+
+            System.Threading.Tasks.Parallel.For(0, count, i =>
+            {
+                var offset = offsets[i];
+                var dirX = offset.DirX;
+                var dirY = offset.DirY;
+                var oppX = -dirX;
+                var oppY = -dirY;
+
+                var (leadingMoving, facingStationary) = vertexCache[(dirX, dirY)];
+
+                var minDist = double.MaxValue;
+
+                // Case 1: Leading moving vertices → stationary entities
+                for (var v = 0; v < leadingMoving.Length; v++)
+                {
+                    var vx = leadingMoving[v].X + offset.Dx;
+                    var vy = leadingMoving[v].Y + offset.Dy;
+
+                    for (var j = 0; j < stationaryEntities.Count; j++)
+                    {
+                        var d = RayEntityDistance(vx, vy, stationaryEntities[j], 0, 0, dirX, dirY);
+
+                        if (d < minDist)
+                        {
+                            minDist = d;
+                            if (d <= 0) { results[i] = 0; return; }
+                        }
+                    }
+                }
+
+                // Case 2: Facing stationary vertices → moving entities (opposite direction)
+                for (var v = 0; v < facingStationary.Length; v++)
+                {
+                    var svx = facingStationary[v].X;
+                    var svy = facingStationary[v].Y;
+
+                    for (var j = 0; j < movingEntities.Count; j++)
+                    {
+                        var d = RayEntityDistance(svx, svy, movingEntities[j], offset.Dx, offset.Dy, oppX, oppY);
+
+                        if (d < minDist)
+                        {
+                            minDist = d;
+                            if (d <= 0) { results[i] = 0; return; }
+                        }
+                    }
+                }
+
+                // Phase 3: Curve-to-curve direct distance.
+                // Vertex sampling misses the true contact between two curved entities
+                // when the approach angle doesn't align with a sampled vertex.
+                for (var m = 0; m < movingCurves.Length; m++)
+                {
+                    var mc = movingCurves[m];
+                    var mcx = mc.Cx + offset.Dx;
+                    var mcy = mc.Cy + offset.Dy;
+
+                    for (var s = 0; s < stationaryCurves.Length; s++)
+                    {
+                        var sc = stationaryCurves[s];
+                        var d = SpatialQuery.RayCircleDistance(
+                            mcx, mcy, sc.Cx, sc.Cy, mc.Radius + sc.Radius, dirX, dirY);
+
+                        if (d >= minDist || d == double.MaxValue)
+                            continue;
+
+                        if (mc.Entity is Arc || sc.Entity is Arc)
+                        {
+                            var mx = mcx + d * dirX;
+                            var my = mcy + d * dirY;
+                            var toCx = sc.Cx - mx;
+                            var toCy = sc.Cy - my;
+
+                            if (mc.Entity is Arc mArc)
+                            {
+                                var angle = Angle.NormalizeRad(System.Math.Atan2(toCy, toCx));
+                                if (!Angle.IsBetweenRad(angle, mArc.StartAngle, mArc.EndAngle, mArc.IsReversed))
+                                    continue;
+                            }
+
+                            if (sc.Entity is Arc sArc)
+                            {
+                                var angle = Angle.NormalizeRad(System.Math.Atan2(-toCy, -toCx));
+                                if (!Angle.IsBetweenRad(angle, sArc.StartAngle, sArc.EndAngle, sArc.IsReversed))
+                                    continue;
+                            }
+                        }
+
+                        minDist = d;
+                        if (d <= 0) { results[i] = 0; return; }
+                    }
+                }
+
+                results[i] = minDist;
+            });
+
+            return results;
+        }
+
+        private readonly struct CurveParams
+        {
+            public readonly Entity Entity;
+            public readonly double Cx, Cy, Radius;
+
+            public CurveParams(Entity entity, double cx, double cy, double radius)
+            {
+                Entity = entity;
+                Cx = cx;
+                Cy = cy;
+                Radius = radius;
+            }
+        }
+
+        private static CurveParams[] ExtractCurveParams(List<Entity> entities)
+        {
+            var curves = new List<CurveParams>();
+            for (var i = 0; i < entities.Count; i++)
+            {
+                if (entities[i] is Circle circle)
+                    curves.Add(new CurveParams(circle, circle.Center.X, circle.Center.Y, circle.Radius));
+                else if (entities[i] is Arc arc)
+                    curves.Add(new CurveParams(arc, arc.Center.X, arc.Center.Y, arc.Radius));
+            }
+            return curves.ToArray();
+        }
+
+        private static double RayEntityDistance(
+            double vx, double vy, Entity entity,
+            double entityOffsetX, double entityOffsetY,
+            double dirX, double dirY)
+        {
+            if (entity is Line line)
+            {
+                return SpatialQuery.RayEdgeDistance(
+                    vx, vy,
+                    line.StartPoint.X + entityOffsetX, line.StartPoint.Y + entityOffsetY,
+                    line.EndPoint.X + entityOffsetX, line.EndPoint.Y + entityOffsetY,
+                    dirX, dirY);
+            }
+
+            if (entity is Arc arc)
+            {
+                return SpatialQuery.RayArcDistance(
+                    vx, vy,
+                    arc.Center.X + entityOffsetX, arc.Center.Y + entityOffsetY,
+                    arc.Radius,
+                    arc.StartAngle, arc.EndAngle, arc.IsReversed,
+                    dirX, dirY);
+            }
+
+            if (entity is Circle circle)
+            {
+                return SpatialQuery.RayCircleDistance(
+                    vx, vy,
+                    circle.Center.X + entityOffsetX, circle.Center.Y + entityOffsetY,
+                    circle.Radius,
+                    dirX, dirY);
+            }
+
+            return double.MaxValue;
+        }
+
+        private static Vector[] ExtractVerticesFromEntities(List<Entity> entities)
+        {
+            var vertices = new HashSet<Vector>();
+
+            for (var i = 0; i < entities.Count; i++)
+            {
+                var entity = entities[i];
+
+                if (entity is Line line)
+                {
+                    vertices.Add(line.StartPoint);
+                    vertices.Add(line.EndPoint);
+                }
+                else if (entity is Arc arc)
+                {
+                    vertices.Add(arc.StartPoint());
+                    vertices.Add(arc.EndPoint());
+                    AddArcExtremes(vertices, arc);
+                }
+                else if (entity is Circle circle)
+                {
+                    // Four cardinal points
+                    vertices.Add(new Vector(circle.Center.X + circle.Radius, circle.Center.Y));
+                    vertices.Add(new Vector(circle.Center.X - circle.Radius, circle.Center.Y));
+                    vertices.Add(new Vector(circle.Center.X, circle.Center.Y + circle.Radius));
+                    vertices.Add(new Vector(circle.Center.X, circle.Center.Y - circle.Radius));
+                }
+            }
+
+            return vertices.ToArray();
+        }
+
+        private static void AddArcExtremes(HashSet<Vector> points, Arc arc)
+        {
+            var a1 = arc.StartAngle;
+            var a2 = arc.EndAngle;
+            var reversed = arc.IsReversed;
+
+            if (reversed)
+                Generic.Swap(ref a1, ref a2);
+
+            // Right (0°)
+            if (Angle.IsBetweenRad(Angle.TwoPI, a1, a2))
+                points.Add(new Vector(arc.Center.X + arc.Radius, arc.Center.Y));
+
+            // Top (90°)
+            if (Angle.IsBetweenRad(Angle.HalfPI, a1, a2))
+                points.Add(new Vector(arc.Center.X, arc.Center.Y + arc.Radius));
+
+            // Left (180°)
+            if (Angle.IsBetweenRad(System.Math.PI, a1, a2))
+                points.Add(new Vector(arc.Center.X - arc.Radius, arc.Center.Y));
+
+            // Bottom (270°)
+            if (Angle.IsBetweenRad(System.Math.PI * 1.5, a1, a2))
+                points.Add(new Vector(arc.Center.X, arc.Center.Y - arc.Radius));
+        }
+
         private static Vector[] ExtractUniqueVertices(List<Line> lines)
         {
             var vertices = new HashSet<Vector>();
@@ -106,11 +351,6 @@ namespace OpenNest.Engine.BestFit
             return vertices.ToArray();
         }
 
-        /// <summary>
-        /// Filters vertices by their projection onto the push direction.
-        /// keepHigh=true returns the leading half (front face, closest to target).
-        /// keepHigh=false returns the facing half (side facing the approaching part).
-        /// </summary>
         private static Vector[] FilterVerticesByProjection(
             Vector[] vertices, double dirX, double dirY, bool keepHigh)
         {

OpenNest.Engine/BestFit/GpuDistanceComputer.cs

@@ -36,6 +36,16 @@ namespace OpenNest.Engine.BestFit
                 flatOffsets, count, directions);
         }
 
+        public double[] ComputeDistances(
+            List<Entity> stationaryEntities,
+            List<Entity> movingEntities,
+            SlideOffset[] offsets)
+        {
+            // GPU path doesn't support native entities yet — fall back to CPU.
+            var cpu = new CpuDistanceComputer();
+            return cpu.ComputeDistances(stationaryEntities, movingEntities, offsets);
+        }
+
         /// <summary>
         /// Maps a unit direction vector to a PushDirection int for the GPU interface.
         /// Left=0, Down=1, Right=2, Up=3.

OpenNest.Engine/BestFit/IDistanceComputer.cs

@@ -9,5 +9,10 @@ namespace OpenNest.Engine.BestFit
             List<Line> stationaryLines,
             List<Line> movingTemplateLines,
             SlideOffset[] offsets);
+
+        double[] ComputeDistances(
+            List<Entity> stationaryEntities,
+            List<Entity> movingEntities,
+            SlideOffset[] offsets);
     }
 }

OpenNest.Engine/BestFit/RotationSlideStrategy.cs

@@ -36,8 +36,8 @@ namespace OpenNest.Engine.BestFit
             var part2Template = Part.CreateAtOrigin(drawing, Part2Rotation);
 
             var halfSpacing = spacing / 2;
-            var part1Lines = PartGeometry.GetOffsetPartLines(part1, halfSpacing);
-            var part2TemplateLines = PartGeometry.GetOffsetPartLines(part2Template, halfSpacing);
+            var part1Entities = PartGeometry.GetOffsetPerimeterEntities(part1, halfSpacing);
+            var part2Entities = PartGeometry.GetOffsetPerimeterEntities(part2Template, halfSpacing);
 
             var bbox1 = part1.BoundingBox;
             var bbox2 = part2Template.BoundingBox;
@@ -48,7 +48,7 @@ namespace OpenNest.Engine.BestFit
                 return candidates;
 
             var distances = _distanceComputer.ComputeDistances(
-                part1Lines, part2TemplateLines, offsets);
+                part1Entities, part2Entities, offsets);
 
             var testNumber = 0;
 
@@ -90,15 +90,18 @@ namespace OpenNest.Engine.BestFit
                 if (isHorizontalPush)
                 {
                     // Perpendicular sweep along Y → Width; push extent along X → Length
-                    perpMin = -(bbox2.Width + spacing);
-                    perpMax = bbox1.Width + bbox2.Width + spacing;
+                    // Trim to offsets where the parts overlap by at least 50%.
+                    var halfOverlap = bbox2.Width * 0.5;
+                    perpMin = -(halfOverlap - spacing);
+                    perpMax = bbox1.Width + halfOverlap + spacing;
                     pushStartOffset = bbox1.Length + bbox2.Length + spacing * 2;
                 }
                 else
                 {
                     // Perpendicular sweep along X → Length; push extent along Y → Width
-                    perpMin = -(bbox2.Length + spacing);
-                    perpMax = bbox1.Length + bbox2.Length + spacing;
+                    var halfOverlap = bbox2.Length * 0.5;
+                    perpMin = -(halfOverlap - spacing);
+                    perpMax = bbox1.Length + halfOverlap + spacing;
                     pushStartOffset = bbox1.Width + bbox2.Width + spacing * 2;
                 }
 

OpenNest.Engine/DefaultNestEngine.cs

@@ -139,24 +139,42 @@ namespace OpenNest
             var bestFits = BestFitCache.GetOrCompute(
                 drawing, Plate.Size.Length, Plate.Size.Width, Plate.PartSpacing);
 
-            var best = SelectBestFitPair(bestFits);
-            if (best == null)
-                return null;
+            List<Part> bestPlacement = null;
 
-            // BuildParts produces landscape orientation (Width >= Height).
-            // Try both landscape and portrait (90° rotated) and let the
-            // engine's comparer pick the better orientation.
-            var landscape = best.BuildParts(drawing);
-            var portrait = RotatePair90(landscape);
+            foreach (var fit in bestFits)
+            {
+                if (!fit.Keep)
+                    continue;
 
-            var lFits = TryOffsetToWorkArea(landscape, workArea);
-            var pFits = TryOffsetToWorkArea(portrait, workArea);
+                // Skip pairs that can't possibly fit the work area in either orientation.
+                if (fit.ShortestSide > System.Math.Min(workArea.Width, workArea.Length) + Tolerance.Epsilon)
+                    continue;
+                if (fit.LongestSide > System.Math.Max(workArea.Width, workArea.Length) + Tolerance.Epsilon)
+                    continue;
 
-            if (!lFits && !pFits)
-                return null;
-            if (lFits && pFits)
-                return IsBetterFill(portrait, landscape, workArea) ? portrait : landscape;
-            return lFits ? landscape : portrait;
+                var landscape = fit.BuildParts(drawing);
+                var portrait = RotatePair90(landscape);
+
+                var lFits = TryOffsetToWorkArea(landscape, workArea);
+                var pFits = TryOffsetToWorkArea(portrait, workArea);
+
+                // Pick the better orientation for this pair.
+                List<Part> candidate = null;
+                if (lFits && pFits)
+                    candidate = IsBetterFill(portrait, landscape, workArea) ? portrait : landscape;
+                else if (lFits)
+                    candidate = landscape;
+                else if (pFits)
+                    candidate = portrait;
+
+                if (candidate == null)
+                    continue;
+
+                if (bestPlacement == null || IsBetterFill(candidate, bestPlacement, workArea))
+                    bestPlacement = candidate;
+            }
+
+            return bestPlacement;
         }
 
         private static List<Part> RotatePair90(List<Part> parts)

OpenNest.Engine/Fill/Compactor.cs

@@ -11,8 +11,6 @@ namespace OpenNest.Engine.Fill
     /// </summary>
     public static class Compactor
     {
-        private const double ChordTolerance = 0.001;
-
         public static double Push(List<Part> movingParts, Plate plate, PushDirection direction)
         {
             var obstacleParts = plate.Parts
@@ -44,7 +42,7 @@ namespace OpenNest.Engine.Fill
             var opposite = -direction;
 
             var obstacleBoxes = new Box[obstacleParts.Count];
-            var obstacleLines = new List<Line>[obstacleParts.Count];
+            var obstacleEntities = new List<Entity>[obstacleParts.Count];
 
             for (var i = 0; i < obstacleParts.Count; i++)
                 obstacleBoxes[i] = obstacleParts[i].BoundingBox;
@@ -61,7 +59,19 @@ namespace OpenNest.Engine.Fill
                     distance = edgeDist;
 
                 var movingBox = moving.BoundingBox;
-                List<Line> movingLines = null;
+                List<Entity> movingEntities = null;
+
+                // Check if any obstacle is inside the moving part — only then
+                // do we need cutout entities on the moving part.
+                var needCutouts = false;
+                for (var i = 0; i < obstacleBoxes.Length; i++)
+                {
+                    if (movingBox.Contains(obstacleBoxes[i]))
+                    {
+                        needCutouts = true;
+                        break;
+                    }
+                }
 
                 for (var i = 0; i < obstacleBoxes.Length; i++)
                 {
@@ -76,15 +86,19 @@ namespace OpenNest.Engine.Fill
                     if (!SpatialQuery.PerpendicularOverlap(movingBox, obstacleBoxes[i], direction))
                         continue;
 
-                    movingLines ??= halfSpacing > 0
-                        ? PartGeometry.GetOffsetPartLines(moving, halfSpacing, direction, ChordTolerance)
-                        : PartGeometry.GetPartLines(moving, direction, ChordTolerance);
+                    movingEntities ??= halfSpacing > 0
+                        ? (needCutouts
+                            ? PartGeometry.GetOffsetPartEntities(moving, halfSpacing)
+                            : PartGeometry.GetOffsetPerimeterEntities(moving, halfSpacing))
+                        : (needCutouts
+                            ? PartGeometry.GetPartEntities(moving)
+                            : PartGeometry.GetPerimeterEntities(moving));
 
-                    obstacleLines[i] ??= halfSpacing > 0
-                        ? PartGeometry.GetOffsetPartLines(obstacleParts[i], halfSpacing, opposite, ChordTolerance)
-                        : PartGeometry.GetPartLines(obstacleParts[i], opposite, ChordTolerance);
+                    obstacleEntities[i] ??= halfSpacing > 0
+                        ? PartGeometry.GetOffsetPerimeterEntities(obstacleParts[i], halfSpacing)
+                        : PartGeometry.GetPerimeterEntities(obstacleParts[i]);
 
-                    var d = SpatialQuery.DirectionalDistance(movingLines, obstacleLines[i], direction);
+                    var d = SpatialQuery.DirectionalDistance(movingEntities, obstacleEntities[i], direction);
                     if (d < distance)
                         distance = d;
                 }
@@ -157,7 +171,7 @@ namespace OpenNest.Engine.Fill
                         continue;
 
                     var gap = SpatialQuery.DirectionalGap(movingBox, obstacleBoxes[i], direction);
-                    var d = gap - partSpacing - 2 * ChordTolerance;
+                    var d = gap - partSpacing - 0.002;
                     if (d < 0) d = 0;
                     if (d < distance)
                         distance = d;

OpenNest.Engine/Fill/FillLinear.cs

@@ -119,10 +119,11 @@ namespace OpenNest.Engine.Fill
             var maxCopyDistance = FindMaxPairDistance(
                 patternA.Parts, boundaries, offset, pushDir, opposite, startOffset);
 
-            if (maxCopyDistance < Tolerance.Epsilon)
-                return bboxDim + PartSpacing;
-
-            return maxCopyDistance;
+            // The copy distance must be at least bboxDim + PartSpacing to prevent
+            // bounding box overlap. Cross-pair slides can underestimate when the
+            // circumscribed polygon boundary overshoots the true arc, creating
+            // spurious contacts between diagonal parts in adjacent copies.
+            return System.Math.Max(maxCopyDistance, bboxDim + PartSpacing);
         }
 
         /// <summary>

OpenNest.Engine/HorizontalRemnantEngine.cs

@@ -1,7 +1,6 @@
 using System;
 using System.Collections.Generic;
 using OpenNest.Engine;
-using OpenNest.Engine.BestFit;
 using OpenNest.Engine.Fill;
 using OpenNest.Geometry;
 using OpenNest.Math;
@@ -27,20 +26,6 @@ namespace OpenNest
 
         public override ShrinkAxis TrimAxis => ShrinkAxis.Length;
 
-        protected override BestFitResult SelectBestFitPair(List<BestFitResult> results)
-        {
-            BestFitResult best = null;
-
-            foreach (var r in results)
-            {
-                if (!r.Keep) continue;
-                if (best == null || r.BoundingHeight < best.BoundingHeight)
-                    best = r;
-            }
-
-            return best;
-        }
-
         public override List<double> BuildAngles(NestItem item, ClassificationResult classification, Box workArea)
         {
             var baseAngles = new List<double> { classification.PrimaryAngle, classification.PrimaryAngle + Angle.HalfPI };

OpenNest.Engine/MultiPlateNester.cs

@@ -0,0 +1,661 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading;
+using OpenNest.Engine.Fill;
+using OpenNest.Geometry;
+using OpenNest.Math;
+
+namespace OpenNest
+{
+    public enum PartClass
+    {
+        Large,
+        Medium,
+        Small,
+    }
+
+    public class MultiPlateNester
+    {
+        private readonly Plate _template;
+        private readonly List<PlateOption> _plateOptions;
+        private readonly List<PlateOption> _sortedOptions;
+        private readonly double _salvageRate;
+        private readonly double _minRemnantSize;
+        private readonly List<PlateResult> _platePool;
+        private readonly IProgress<NestProgress> _progress;
+        private readonly CancellationToken _token;
+        private readonly MultiPlateNestOptions _options;
+
+        private bool HasPlateOptions => _plateOptions != null && _plateOptions.Count > 0;
+
+        private MultiPlateNester(
+            MultiPlateNestOptions options,
+            List<Plate> existingPlates,
+            IProgress<NestProgress> progress, CancellationToken token)
+        {
+            _options = options;
+            _template = options.Template;
+            _plateOptions = options.PlateOptions;
+            _sortedOptions = options.PlateOptions?.OrderBy(o => o.Cost).ToList();
+            _salvageRate = options.SalvageRate;
+            _minRemnantSize = options.MinRemnantSize;
+            _platePool = InitializePlatePool(existingPlates);
+            _progress = progress;
+            _token = token;
+        }
+
+        // --- Static Utility Methods ---
+
+        public static bool FitsBounds(Box container, Box part)
+        {
+            var fitsNormal = container.Width >= part.Width - Tolerance.Epsilon
+                          && container.Length >= part.Length - Tolerance.Epsilon;
+            var fitsRotated = container.Width >= part.Length - Tolerance.Epsilon
+                           && container.Length >= part.Width - Tolerance.Epsilon;
+            return fitsNormal || fitsRotated;
+        }
+
+        public static List<NestItem> SortItems(List<NestItem> items, PartSortOrder sortOrder)
+        {
+            var withBounds = items.Select(i => (Item: i, Bounds: i.Drawing.Program.BoundingBox())).ToList();
+
+            switch (sortOrder)
+            {
+                case PartSortOrder.BoundingBoxArea:
+                    return withBounds
+                        .OrderByDescending(x => x.Bounds.Width * x.Bounds.Length)
+                        .Select(x => x.Item)
+                        .ToList();
+
+                case PartSortOrder.Size:
+                    return withBounds
+                        .OrderByDescending(x => System.Math.Max(x.Bounds.Width, x.Bounds.Length))
+                        .Select(x => x.Item)
+                        .ToList();
+
+                default:
+                    return items.ToList();
+            }
+        }
+
+        public static PartClass Classify(Box partBounds, Box workArea)
+        {
+            var halfWidth = workArea.Width / 2.0;
+            var halfLength = workArea.Length / 2.0;
+
+            if (partBounds.Width > halfWidth || partBounds.Length > halfLength)
+                return PartClass.Large;
+
+            var workAreaArea = workArea.Width * workArea.Length;
+            var partArea = partBounds.Width * partBounds.Length;
+
+            if (partArea > workAreaArea / 9.0)
+                return PartClass.Medium;
+
+            return PartClass.Small;
+        }
+
+        public static bool IsScrapRemnant(Box remnant, double minRemnantSize)
+        {
+            return remnant.Width < minRemnantSize && remnant.Length < minRemnantSize;
+        }
+
+        public static List<Box> FindRemnants(Plate plate, double minRemnantSize, bool scrapOnly)
+        {
+            var remnants = RemnantFinder.FromPlate(plate).FindRemnants();
+            return remnants.Where(r => IsScrapRemnant(r, minRemnantSize) == scrapOnly).ToList();
+        }
+
+        public struct UpgradeDecision
+        {
+            public bool ShouldUpgrade;
+            public double UpgradeCost;
+            public double NewPlateCost;
+        }
+
+        public static Plate CreatePlate(Plate template, List<PlateOption> options, Box minBounds)
+        {
+            var plate = new Plate(template.Size)
+            {
+                PartSpacing = template.PartSpacing,
+                Quadrant = template.Quadrant,
+            };
+            plate.EdgeSpacing = new Spacing
+            {
+                Left = template.EdgeSpacing.Left,
+                Right = template.EdgeSpacing.Right,
+                Top = template.EdgeSpacing.Top,
+                Bottom = template.EdgeSpacing.Bottom,
+            };
+
+            if (options == null || options.Count == 0 || minBounds == null)
+                return plate;
+
+            var sorted = options.OrderBy(o => o.Cost).ToList();
+
+            foreach (var option in sorted)
+            {
+                if (FitsBounds(OptionWorkArea(option, template), minBounds))
+                {
+                    plate.Size = new Size(option.Width, option.Length);
+                    return plate;
+                }
+            }
+
+            return plate;
+        }
+
+        public static UpgradeDecision EvaluateUpgradeVsNew(
+            PlateOption currentSize,
+            PlateOption upgradeSize,
+            PlateOption newPlateSize,
+            double salvageRate,
+            double estimatedNewPlateUtilization)
+        {
+            var upgradeCost = upgradeSize.Cost - currentSize.Cost;
+
+            var newPlateCost = newPlateSize.Cost;
+            var remnantFraction = 1.0 - estimatedNewPlateUtilization;
+            var salvageCredit = remnantFraction * newPlateSize.Cost * salvageRate;
+            var netNewCost = newPlateCost - salvageCredit;
+
+            return new UpgradeDecision
+            {
+                ShouldUpgrade = upgradeCost <= netNewCost,
+                UpgradeCost = upgradeCost,
+                NewPlateCost = netNewCost,
+            };
+        }
+
+        // --- Main Entry Point ---
+
+        public static MultiPlateResult Nest(
+            List<NestItem> items,
+            MultiPlateNestOptions options,
+            List<Plate> existingPlates = null,
+            IProgress<NestProgress> progress = null,
+            CancellationToken token = default)
+        {
+            var nester = new MultiPlateNester(options, existingPlates, progress, token);
+            return nester.Run(items, options.SortOrder, options.AllowPlateCreation);
+        }
+
+        // --- Private Helpers ---
+
+        private static Box OptionWorkArea(PlateOption option, Plate template)
+        {
+            var w = option.Width - template.EdgeSpacing.Left - template.EdgeSpacing.Right;
+            var h = option.Length - template.EdgeSpacing.Top - template.EdgeSpacing.Bottom;
+            return new Box(0, 0, w, h);
+        }
+
+        private static double ScoreZone(Box zone, Box partBounds)
+        {
+            if (!FitsBounds(zone, partBounds))
+                return -1;
+
+            var cols = (int)(zone.Width / partBounds.Width);
+            var rows = (int)(zone.Length / partBounds.Length);
+            var colsR = (int)(zone.Width / partBounds.Length);
+            var rowsR = (int)(zone.Length / partBounds.Width);
+            var estimatedCount = System.Math.Max(cols * rows, colsR * rowsR);
+
+            var utilization = (estimatedCount * partBounds.Width * partBounds.Length) / zone.Area();
+
+            var zoneAspect = zone.Width / zone.Length;
+            var partAspect = partBounds.Width / partBounds.Length;
+            var aspectMatch = System.Math.Min(zoneAspect, partAspect) / System.Math.Max(zoneAspect, partAspect);
+
+            return utilization * 0.7 + aspectMatch * 0.3;
+        }
+
+        private static void DecrementQuantity(NestItem item, int placed)
+        {
+            item.Quantity = System.Math.Max(0, item.Quantity - placed);
+        }
+
+        private int FillAndPlace(PlateResult pr, Box zone, NestItem item)
+        {
+            var engine = NestEngineRegistry.Create(pr.Plate);
+            var clonedItem = CloneItem(item);
+            var parts = engine.Fill(clonedItem, zone, _progress, _token);
+
+            if (parts.Count > 0)
+            {
+                pr.AddParts(parts);
+                DecrementQuantity(item, parts.Count);
+            }
+
+            return parts.Count;
+        }
+
+        private PlateResult CreateNewPlateResult(Plate plate)
+        {
+            var pr = new PlateResult { Plate = plate, IsNew = true };
+
+            if (HasPlateOptions)
+            {
+                pr.ChosenSize = _plateOptions.FirstOrDefault(o =>
+                    o.Width.IsEqualTo(plate.Size.Width) && o.Length.IsEqualTo(plate.Size.Length));
+            }
+
+            return pr;
+        }
+
+        private static NestItem CloneItem(NestItem item)
+        {
+            return new NestItem
+            {
+                Drawing = item.Drawing,
+                Priority = item.Priority,
+                Quantity = item.Quantity,
+                StepAngle = item.StepAngle,
+                RotationStart = item.RotationStart,
+                RotationEnd = item.RotationEnd,
+            };
+        }
+
+        private static List<PlateResult> InitializePlatePool(List<Plate> existingPlates)
+        {
+            var pool = new List<PlateResult>();
+
+            if (existingPlates != null)
+            {
+                foreach (var plate in existingPlates)
+                    pool.Add(new PlateResult { Plate = plate, IsNew = false });
+            }
+
+            return pool;
+        }
+
+        private bool TryWithUpgradedSize(PlateResult pr, PlateOption upgradeOption, Func<List<Box>, bool> tryFill)
+        {
+            var oldSize = pr.Plate.Size;
+            var oldChosenSize = pr.ChosenSize;
+
+            pr.Plate.Size = new Size(upgradeOption.Width, upgradeOption.Length);
+            pr.ChosenSize = upgradeOption;
+
+            var remnants = RemnantFinder.FromPlate(pr.Plate).FindRemnants();
+
+            if (remnants.Count > 0 && tryFill(remnants))
+                return true;
+
+            pr.Plate.Size = oldSize;
+            pr.ChosenSize = oldChosenSize;
+            return false;
+        }
+
+        private PlateOption FindSmallestFittingOption(Box partBounds)
+        {
+            return _sortedOptions?.FirstOrDefault(o => FitsBounds(OptionWorkArea(o, _template), partBounds));
+        }
+
+        // --- Orchestration ---
+
+        private MultiPlateResult Run(List<NestItem> items, PartSortOrder sortOrder, bool allowPlateCreation)
+        {
+            var result = new MultiPlateResult();
+
+            if (items == null || items.Count == 0)
+                return result;
+
+            var sorted = SortItems(items.Where(i => i.Quantity > 0).ToList(), sortOrder);
+
+            foreach (var item in sorted)
+            {
+                if (_token.IsCancellationRequested || item.Quantity <= 0)
+                    continue;
+
+                var bb = item.Drawing.Program.BoundingBox();
+
+                TryPlaceOnExistingPlates(item, bb);
+
+                var templateClass = Classify(bb, _template.WorkArea());
+
+                if (item.Quantity > 0 && allowPlateCreation && templateClass != PartClass.Small)
+                {
+                    PlaceOnNewPlates(item, bb);
+
+                    if (item.Quantity > 0 && HasPlateOptions)
+                        TryUpgradeOrNewPlate(item, bb);
+                }
+            }
+
+            var leftovers = sorted.Where(i => i.Quantity > 0).ToList();
+
+            if (leftovers.Count > 0 && allowPlateCreation && !_token.IsCancellationRequested)
+            {
+                PackIntoExistingRemnants(leftovers);
+                CreateSharedPlates(leftovers);
+            }
+
+            if (HasPlateOptions && !_token.IsCancellationRequested)
+                TryConsolidateTailPlates();
+
+            foreach (var item in sorted.Where(i => i.Quantity > 0))
+                result.UnplacedItems.Add(item);
+
+            result.Plates.AddRange(_platePool.Where(p => p.Parts.Count > 0 || p.IsNew));
+            return result;
+        }
+
+        private void PackIntoExistingRemnants(List<NestItem> leftovers)
+        {
+            foreach (var pr in _platePool)
+            {
+                if (_token.IsCancellationRequested)
+                    break;
+
+                var anyPlaced = true;
+                while (anyPlaced && !_token.IsCancellationRequested)
+                {
+                    anyPlaced = false;
+
+                    var remaining = leftovers.Where(i => i.Quantity > 0).ToList();
+                    if (remaining.Count == 0)
+                        break;
+
+                    var remnants = RemnantFinder.FromPlate(pr.Plate).FindRemnants();
+                    if (remnants.Count == 0)
+                        break;
+
+                    var engine = NestEngineRegistry.Create(pr.Plate);
+
+                    foreach (var remnant in remnants)
+                    {
+                        remaining = leftovers.Where(i => i.Quantity > 0).ToList();
+                        if (remaining.Count == 0)
+                            break;
+
+                        var cloned = remaining.Select(CloneItem).ToList();
+                        var parts = engine.PackArea(remnant, cloned, _progress, _token);
+
+                        if (parts.Count > 0)
+                        {
+                            pr.AddParts(parts);
+                            anyPlaced = true;
+
+                            foreach (var item in remaining)
+                            {
+                                var placed = parts.Count(p => p.BaseDrawing == item.Drawing);
+                                DecrementQuantity(item, placed);
+                            }
+                        }
+                    }
+                }
+            }
+        }
+
+        private void CreateSharedPlates(List<NestItem> leftovers)
+        {
+            leftovers.RemoveAll(i => i.Quantity <= 0);
+
+            while (leftovers.Count > 0 && !_token.IsCancellationRequested)
+            {
+                var plate = CreatePlate(_template, _plateOptions, null);
+                var pr = CreateNewPlateResult(plate);
+                var placedAny = false;
+
+                foreach (var item in leftovers)
+                {
+                    if (item.Quantity <= 0 || _token.IsCancellationRequested)
+                        continue;
+
+                    var remnants = !placedAny
+                        ? new List<Box> { plate.WorkArea() }
+                        : RemnantFinder.FromPlate(plate).FindRemnants();
+
+                    if (remnants.Count == 0)
+                        break;
+
+                    var engine = NestEngineRegistry.Create(plate);
+
+                    foreach (var remnant in remnants)
+                    {
+                        if (item.Quantity <= 0)
+                            break;
+
+                        var clonedItem = CloneItem(item);
+                        var parts = engine.Fill(clonedItem, remnant, _progress, _token);
+
+                        if (parts.Count > 0)
+                        {
+                            pr.AddParts(parts);
+                            DecrementQuantity(item, parts.Count);
+                            placedAny = true;
+                        }
+                    }
+                }
+
+                if (!placedAny)
+                    break;
+
+                _platePool.Add(pr);
+                leftovers.RemoveAll(i => i.Quantity <= 0);
+            }
+        }
+
+        private bool TryPlaceOnExistingPlates(NestItem item, Box partBounds)
+        {
+            var anyPlaced = false;
+            var remnantCache = new Dictionary<PlateResult, List<Box>>();
+            PlateResult lastModified = null;
+
+            while (item.Quantity > 0 && !_token.IsCancellationRequested)
+            {
+                PlateResult bestPlate = null;
+                Box bestZone = null;
+                var bestScore = double.MinValue;
+
+                foreach (var pr in _platePool)
+                {
+                    if (_token.IsCancellationRequested)
+                        break;
+
+                    if (pr == lastModified || !remnantCache.ContainsKey(pr))
+                    {
+                        var workArea = pr.Plate.WorkArea();
+                        var classification = Classify(partBounds, workArea);
+
+                        remnantCache[pr] = classification == PartClass.Small
+                            ? FindRemnants(pr.Plate, _minRemnantSize, scrapOnly: true)
+                            : FindRemnants(pr.Plate, _minRemnantSize, scrapOnly: false);
+                    }
+
+                    foreach (var zone in remnantCache[pr])
+                    {
+                        var score = ScoreZone(zone, partBounds);
+                        if (score > bestScore)
+                        {
+                            bestPlate = pr;
+                            bestZone = zone;
+                            bestScore = score;
+                        }
+                    }
+                }
+
+                if (bestPlate == null || bestZone == null)
+                    break;
+
+                if (FillAndPlace(bestPlate, bestZone, item) == 0)
+                    break;
+
+                lastModified = bestPlate;
+                anyPlaced = true;
+            }
+
+            return anyPlaced;
+        }
+
+        private bool PlaceOnNewPlates(NestItem item, Box partBounds)
+        {
+            var anyPlaced = false;
+
+            while (item.Quantity > 0 && !_token.IsCancellationRequested)
+            {
+                var plate = CreatePlate(_template, _plateOptions, partBounds);
+                var workArea = plate.WorkArea();
+
+                if (!FitsBounds(workArea, partBounds))
+                    break;
+
+                var pr = CreateNewPlateResult(plate);
+
+                if (FillAndPlace(pr, workArea, item) == 0)
+                    break;
+
+                _platePool.Add(pr);
+                anyPlaced = true;
+            }
+
+            return anyPlaced;
+        }
+
+        private bool TryUpgradeOrNewPlate(NestItem item, Box partBounds)
+        {
+            if (!HasPlateOptions)
+                return false;
+
+            foreach (var pr in _platePool.Where(p => p.IsNew && p.ChosenSize != null))
+            {
+                var currentOption = pr.ChosenSize;
+                var currentIdx = _sortedOptions.FindIndex(o =>
+                    o.Width.IsEqualTo(currentOption.Width) && o.Length.IsEqualTo(currentOption.Length));
+
+                if (currentIdx < 0 || currentIdx >= _sortedOptions.Count - 1)
+                    continue;
+
+                for (var i = currentIdx + 1; i < _sortedOptions.Count; i++)
+                {
+                    var upgradeOption = _sortedOptions[i];
+
+                    if (upgradeOption.Width < currentOption.Width - Tolerance.Epsilon
+                        || upgradeOption.Length < currentOption.Length - Tolerance.Epsilon)
+                        continue;
+
+                    var smallestNew = FindSmallestFittingOption(partBounds);
+
+                    if (smallestNew == null)
+                        continue;
+
+                    var utilEst = pr.Plate.Utilization();
+                    var decision = EvaluateUpgradeVsNew(currentOption, upgradeOption, smallestNew,
+                        _salvageRate, utilEst);
+
+                    if (decision.ShouldUpgrade)
+                    {
+                        var placed = TryWithUpgradedSize(pr, upgradeOption, remnants =>
+                        {
+                            foreach (var remnant in remnants)
+                            {
+                                if (FillAndPlace(pr, remnant, item) > 0)
+                                    return true;
+                            }
+                            return false;
+                        });
+
+                        if (placed)
+                            return true;
+                    }
+                }
+            }
+
+            return false;
+        }
+
+        private void TryConsolidateTailPlates()
+        {
+            var consolidated = true;
+            while (consolidated)
+            {
+                consolidated = false;
+
+                var activePlates = _platePool.Where(p => p.Parts.Count > 0 && p.IsNew).ToList();
+                if (activePlates.Count < 2)
+                    return;
+
+                var donors = activePlates.OrderBy(p => p.Plate.Utilization()).ToList();
+
+                foreach (var donor in donors)
+                {
+                    if (donor.Parts.Count == 0)
+                        continue;
+
+                    var donorParts = donor.Parts.ToList();
+                    var absorbed = false;
+
+                    foreach (var target in activePlates)
+                    {
+                        if (target == donor || target.ChosenSize == null || target.Parts.Count == 0)
+                            continue;
+
+                        var currentOption = target.ChosenSize;
+
+                        foreach (var upgradeOption in _sortedOptions.Where(o =>
+                            o.Width >= currentOption.Width - Tolerance.Epsilon
+                            && o.Length >= currentOption.Length - Tolerance.Epsilon
+                            && (o.Width > currentOption.Width + Tolerance.Epsilon
+                                || o.Length > currentOption.Length + Tolerance.Epsilon)))
+                        {
+                            absorbed = TryWithUpgradedSize(target, upgradeOption, remnants =>
+                            {
+                                var engine = NestEngineRegistry.Create(target.Plate);
+                                var tempItems = donorParts
+                                    .GroupBy(p => p.BaseDrawing)
+                                    .Select(g => new NestItem
+                                    {
+                                        Drawing = g.Key,
+                                        Quantity = g.Count(),
+                                    })
+                                    .ToList();
+
+                                var totalPlaced = new List<Part>();
+                                foreach (var remnant in remnants)
+                                {
+                                    var placed = engine.PackArea(remnant, tempItems, _progress, _token);
+                                    totalPlaced.AddRange(placed);
+
+                                    foreach (var ti in tempItems)
+                                    {
+                                        var count = placed.Count(p => p.BaseDrawing == ti.Drawing);
+                                        ti.Quantity = System.Math.Max(0, ti.Quantity - count);
+                                    }
+
+                                    if (tempItems.All(ti => ti.Quantity <= 0))
+                                        break;
+                                }
+
+                                if (totalPlaced.Count >= donorParts.Count)
+                                {
+                                    target.AddParts(totalPlaced);
+
+                                    foreach (var p in donorParts)
+                                        donor.Plate.Parts.Remove(p);
+                                    donor.Parts.Clear();
+                                    _platePool.Remove(donor);
+                                    return true;
+                                }
+
+                                return false;
+                            });
+
+                            if (absorbed)
+                                break;
+                        }
+
+                        if (absorbed)
+                            break;
+                    }
+
+                    if (absorbed)
+                    {
+                        consolidated = true;
+                        break;
+                    }
+                }
+            }
+        }
+    }
+}

OpenNest.Engine/MultiPlateResult.cs

@@ -0,0 +1,34 @@
+using System.Collections.Generic;
+
+namespace OpenNest
+{
+    public class MultiPlateNestOptions
+    {
+        public Plate Template { get; set; }
+        public List<PlateOption> PlateOptions { get; set; }
+        public double SalvageRate { get; set; } = 0.5;
+        public PartSortOrder SortOrder { get; set; } = PartSortOrder.BoundingBoxArea;
+        public double MinRemnantSize { get; set; } = 12.0;
+        public bool AllowPlateCreation { get; set; } = true;
+    }
+
+    public class MultiPlateResult
+    {
+        public List<PlateResult> Plates { get; set; } = new();
+        public List<NestItem> UnplacedItems { get; set; } = new();
+    }
+
+    public class PlateResult
+    {
+        public Plate Plate { get; set; }
+        public List<Part> Parts { get; set; } = new();
+        public PlateOption ChosenSize { get; set; }
+        public bool IsNew { get; set; }
+
+        public void AddParts(IList<Part> parts)
+        {
+            Plate.Parts.AddRange(parts);
+            Parts.AddRange(parts);
+        }
+    }
+}

OpenNest.Engine/NestEngineBase.cs

@@ -56,11 +56,6 @@ namespace OpenNest
 
         protected FillPolicy BuildPolicy() => new FillPolicy(Comparer, PreferredDirection);
 
-        protected virtual BestFitResult SelectBestFitPair(List<BestFitResult> results)
-        {
-            return results.FirstOrDefault(r => r.Keep);
-        }
-
         // --- Virtual methods (side-effect-free, return parts) ---
 
         public virtual List<Part> Fill(NestItem item, Box workArea,
@@ -338,45 +333,56 @@ namespace OpenNest
 
                 var bestFits = BestFitCache.GetOrCompute(
                     item.Drawing, Plate.Size.Length, Plate.Size.Width, Plate.PartSpacing);
-                var bestFit = SelectBestFitPair(bestFits);
-                if (bestFit == null) continue;
 
-                var parts = bestFit.BuildParts(item.Drawing);
-                var pairBbox = ((IEnumerable<IBoundable>)parts).GetBoundingBox();
-                var pairW = pairBbox.Width;
-                var pairL = pairBbox.Length;
-                var minDim = System.Math.Min(pairW, pairL);
+                List<Part> bestPlacement = null;
+                Box bestTarget = null;
 
-                var remnants = finder.FindRemnants(minDim);
-                Box target = null;
-
-                foreach (var r in remnants)
+                foreach (var fit in bestFits)
                 {
-                    if (pairW <= r.Width + Tolerance.Epsilon &&
-                        pairL <= r.Length + Tolerance.Epsilon)
+                    if (!fit.Keep)
+                        continue;
+
+                    var parts = fit.BuildParts(item.Drawing);
+                    var pairBbox = ((IEnumerable<IBoundable>)parts).GetBoundingBox();
+                    var pairW = pairBbox.Width;
+                    var pairL = pairBbox.Length;
+                    var minDim = System.Math.Min(pairW, pairL);
+
+                    var remnants = finder.FindRemnants(minDim);
+
+                    foreach (var r in remnants)
                     {
-                        target = r;
-                        break;
+                        if (pairW <= r.Width + Tolerance.Epsilon &&
+                            pairL <= r.Length + Tolerance.Epsilon)
+                        {
+                            var offset = r.Location - pairBbox.Location;
+                            foreach (var p in parts)
+                            {
+                                p.Offset(offset);
+                                p.UpdateBounds();
+                            }
+
+                            if (bestPlacement == null || IsBetterFill(parts, bestPlacement, r))
+                            {
+                                bestPlacement = parts;
+                                bestTarget = r;
+                            }
+                            break;
+                        }
                     }
                 }
 
-                if (target == null) continue;
+                if (bestPlacement == null) continue;
 
-                var offset = target.Location - pairBbox.Location;
-                foreach (var p in parts)
-                {
-                    p.Offset(offset);
-                    p.UpdateBounds();
-                }
-
-                result.AddRange(parts);
+                result.AddRange(bestPlacement);
                 item.Quantity = 0;
 
-                var envelope = ((IEnumerable<IBoundable>)parts).GetBoundingBox();
+                var envelope = ((IEnumerable<IBoundable>)bestPlacement).GetBoundingBox();
                 finder.AddObstacle(envelope.Offset(Plate.PartSpacing));
 
                 Debug.WriteLine($"[Nest] Placed best-fit pair for {item.Drawing.Name} " +
-                    $"at ({target.X:F1},{target.Y:F1}), size {pairW:F1}x{pairL:F1}");
+                    $"at ({bestTarget.X:F1},{bestTarget.Y:F1}), " +
+                    $"size {envelope.Width:F1}x{envelope.Length:F1}");
             }
 
             return result;

OpenNest.Engine/PartSortOrder.cs

@@ -0,0 +1,8 @@
+namespace OpenNest
+{
+    public enum PartSortOrder
+    {
+        BoundingBoxArea,
+        Size,
+    }
+}

OpenNest.Engine/PlateOptimizer.cs

@@ -1,4 +1,5 @@
 using OpenNest.Engine;
+using OpenNest.Engine.BestFit;
 using OpenNest.Geometry;
 using OpenNest.Math;
 using System;
@@ -22,7 +23,8 @@ namespace OpenNest
             if (items == null || items.Count == 0 || plateOptions == null || plateOptions.Count == 0)
                 return null;
 
-            // Find the minimum dimension needed to fit the largest part.
+            // Find the minimum dimension needed to fit the largest part,
+            // skipping items that are too large for every plate option.
             var minPartWidth = 0.0;
             var minPartLength = 0.0;
             foreach (var item in items)
@@ -31,6 +33,14 @@ namespace OpenNest
                 var bb = item.Drawing.Program.BoundingBox();
                 var shortSide = System.Math.Min(bb.Width, bb.Length);
                 var longSide = System.Math.Max(bb.Width, bb.Length);
+
+                if (!plateOptions.Any(o => FitsPart(o, shortSide, longSide, templatePlate.EdgeSpacing)))
+                {
+                    Debug.WriteLine($"[PlateOptimizer] Skipping oversized item '{item.Drawing.Name}' " +
+                        $"({shortSide:F1}x{longSide:F1}) — does not fit any plate option");
+                    continue;
+                }
+
                 if (shortSide > minPartWidth) minPartWidth = shortSide;
                 if (longSide > minPartLength) minPartLength = longSide;
             }
@@ -44,6 +54,19 @@ namespace OpenNest
             if (candidates.Count == 0)
                 return null;
 
+            // Pre-compute best fits for all candidate plate sizes at once.
+            // This runs the expensive GPU evaluation once on the largest plate
+            // and filters the results for each smaller size.
+            var plateSizes = candidates
+                .Select(o => (Width: o.Length, Height: o.Width))
+                .ToList();
+
+            foreach (var item in items)
+            {
+                if (item.Quantity <= 0) continue;
+                BestFitCache.ComputeForSizes(item.Drawing, templatePlate.PartSpacing, plateSizes);
+            }
+
             PlateOptimizerResult best = null;
 
             foreach (var option in candidates)
@@ -58,9 +81,10 @@ namespace OpenNest
                 if (IsBetter(result, best))
                     best = result;
 
-                // Early exit: when salvage is zero, cheapest plate that fits everything wins.
-                // With salvage > 0, larger plates may have lower net cost, so keep searching.
-                if (salvageRate <= 0)
+                // Early exit: when all items fit, larger plates can only have
+                // worse utilization and higher cost. With salvage < 100%, the
+                // remnant credit never offsets the extra plate cost, so skip.
+                if (salvageRate < 1.0)
                 {
                     var allPlaced = items.All(i => i.Quantity <= 0 ||
                         result.Parts.Count(p => p.BaseDrawing.Name == i.Drawing.Name) >= i.Quantity);
@@ -158,8 +182,8 @@ namespace OpenNest
             if (!candidate.NetCost.IsEqualTo(current.NetCost))
                 return candidate.NetCost < current.NetCost;
 
-            // 3. Smaller plate area as tiebreak.
-            return candidate.ChosenSize.Area < current.ChosenSize.Area;
+            // 3. Higher utilization (tighter density) as tiebreak.
+            return candidate.Utilization > current.Utilization;
         }
     }
 }

OpenNest.Engine/PlateProcessingResult.cs

@@ -4,7 +4,7 @@ using System.Collections.Generic;
 
 namespace OpenNest.Engine
 {
-    public class PlateResult
+    public class PlateProcessingResult
     {
         public List<ProcessedPart> Parts { get; init; }
     }

OpenNest.Engine/PlateProcessor.cs

@@ -14,7 +14,7 @@ namespace OpenNest.Engine
         public ContourCuttingStrategy CuttingStrategy { get; set; }
         public IRapidPlanner RapidPlanner { get; set; }
 
-        public PlateResult Process(Plate plate)
+        public PlateProcessingResult Process(Plate plate)
         {
             var sequenced = Sequencer.Sequence(plate.Parts.ToList(), plate);
             var results = new List<ProcessedPart>(sequenced.Count);
@@ -66,7 +66,7 @@ namespace OpenNest.Engine
                 currentPoint = ToPlateSpace(lastCutLocal, part);
             }
 
-            return new PlateResult { Parts = results };
+            return new PlateProcessingResult { Parts = results };
         }
 
         private static Vector ToPartLocal(Vector platePoint, Part part)

OpenNest.Engine/VerticalRemnantEngine.cs

@@ -1,7 +1,6 @@
 using System;
 using System.Collections.Generic;
 using OpenNest.Engine;
-using OpenNest.Engine.BestFit;
 using OpenNest.Engine.Fill;
 using OpenNest.Geometry;
 using OpenNest.Math;
@@ -25,20 +24,6 @@ namespace OpenNest
 
         public override NestDirection? PreferredDirection => NestDirection.Horizontal;
 
-        protected override BestFitResult SelectBestFitPair(List<BestFitResult> results)
-        {
-            BestFitResult best = null;
-
-            foreach (var r in results)
-            {
-                if (!r.Keep) continue;
-                if (best == null || r.BoundingHeight < best.BoundingHeight)
-                    best = r;
-            }
-
-            return best;
-        }
-
         public override List<double> BuildAngles(NestItem item, ClassificationResult classification, Box workArea)
         {
             var baseAngles = new List<double> { classification.PrimaryAngle, classification.PrimaryAngle + Angle.HalfPI };

OpenNest.IO/Dxf.cs

@@ -0,0 +1,378 @@
+using ACadSharp;
+using ACadSharp.IO;
+using CSMath;
+using OpenNest.CNC;
+using OpenNest.Geometry;
+using OpenNest.Math;
+using System;
+using System.Collections.Generic;
+using System.Diagnostics;
+using System.IO;
+
+namespace OpenNest.IO
+{
+    using AcadArc = ACadSharp.Entities.Arc;
+    using AcadCircle = ACadSharp.Entities.Circle;
+    using AcadLine = ACadSharp.Entities.Line;
+    using Layer = ACadSharp.Tables.Layer;
+
+    public static class Dxf
+    {
+        #region Import
+
+        /// <summary>
+        /// Imports a DXF file, returning both converted entities and the raw CadDocument
+        /// for bend detection. The CadDocument is NOT disposed — caller can use it for
+        /// additional analysis (e.g., MText extraction for bend notes).
+        /// </summary>
+        public static DxfImportResult Import(string path)
+        {
+            using var reader = new DxfReader(path);
+            var doc = reader.Read();
+
+            return new DxfImportResult
+            {
+                Entities = ConvertEntities(doc),
+                Document = doc
+            };
+        }
+
+        public static List<Entity> GetGeometry(string path)
+        {
+            try
+            {
+                using var reader = new DxfReader(path);
+                var doc = reader.Read();
+                return ConvertEntities(doc);
+            }
+            catch (Exception ex)
+            {
+                Debug.WriteLine(ex.Message);
+                return new List<Entity>();
+            }
+        }
+
+        public static List<Entity> GetGeometry(Stream stream)
+        {
+            try
+            {
+                using var reader = new DxfReader(stream);
+                var doc = reader.Read();
+                return ConvertEntities(doc);
+            }
+            catch (Exception ex)
+            {
+                Debug.WriteLine(ex.Message);
+                return new List<Entity>();
+            }
+        }
+
+        #endregion
+
+        #region Export
+
+        public static void ExportProgram(Program program, string path)
+        {
+            using var stream = File.Create(path);
+            ExportProgram(program, stream);
+        }
+
+        public static void ExportProgram(Program program, Stream stream)
+        {
+            var ctx = new ExportContext();
+            ctx.AddProgram(program);
+
+            using var writer = new DxfWriter(stream, ctx.Document, false);
+            writer.Write();
+        }
+
+        public static void ExportPlate(Plate plate, string path)
+        {
+            using var stream = File.Create(path);
+            ExportPlate(plate, stream);
+        }
+
+        public static void ExportPlate(Plate plate, Stream stream)
+        {
+            var ctx = new ExportContext();
+            ctx.AddPlateOutline(plate);
+
+            foreach (var part in plate.Parts)
+            {
+                var endpt = part.Location.ToAcadXYZ();
+                ctx.AddLine(ctx.CurPos, endpt, ctx.RapidLayer);
+                ctx.CurPos = part.Location.ToAcadXYZ();
+                ctx.AddProgram(part.Program);
+            }
+
+            using var writer = new DxfWriter(stream, ctx.Document, false);
+            writer.Write();
+        }
+
+        #endregion
+
+        #region Private
+
+        private static List<Entity> ConvertEntities(CadDocument doc)
+        {
+            var entities = new List<Entity>();
+            var lines = new List<Line>();
+            var arcs = new List<Arc>();
+
+            foreach (var entity in doc.Entities)
+            {
+                if (IsNonCutLayer(entity.Layer?.Name))
+                    continue;
+
+                switch (entity)
+                {
+                    case ACadSharp.Entities.Line line:
+                        lines.Add(line.ToOpenNest());
+                        break;
+
+                    case ACadSharp.Entities.Arc arc:
+                        arcs.Add(arc.ToOpenNest());
+                        break;
+
+                    case ACadSharp.Entities.Circle circle:
+                        entities.Add(circle.ToOpenNest());
+                        break;
+
+                    case ACadSharp.Entities.Spline spline:
+                        foreach (var e in spline.ToOpenNest())
+                        {
+                            if (e is Line l) lines.Add(l);
+                            else if (e is Arc a) arcs.Add(a);
+                        }
+                        break;
+
+                    case ACadSharp.Entities.LwPolyline lwPolyline:
+                        lines.AddRange(lwPolyline.ToOpenNest());
+                        break;
+
+                    case ACadSharp.Entities.Polyline polyline:
+                        lines.AddRange(polyline.ToOpenNest());
+                        break;
+
+                    case ACadSharp.Entities.Ellipse ellipse:
+                        foreach (var e in ellipse.ToOpenNest())
+                        {
+                            if (e is Line l) lines.Add(l);
+                            else if (e is Arc a) arcs.Add(a);
+                        }
+                        break;
+                }
+            }
+
+            GeometryOptimizer.Optimize(lines);
+            GeometryOptimizer.Optimize(arcs);
+
+            entities.AddRange(lines);
+            entities.AddRange(arcs);
+
+            return entities;
+        }
+
+        private static bool IsNonCutLayer(string layerName)
+        {
+            return string.Equals(layerName, "BEND", StringComparison.OrdinalIgnoreCase)
+                || string.Equals(layerName, "ETCH", StringComparison.OrdinalIgnoreCase);
+        }
+
+        private class ExportContext
+        {
+            public CadDocument Document { get; }
+            public XYZ CurPos { get; set; }
+            public Layer CutLayer { get; }
+            public Layer RapidLayer { get; }
+            public Layer PlateLayer { get; }
+
+            private Mode mode;
+
+            public ExportContext()
+            {
+                Document = new CadDocument();
+
+                CutLayer = new Layer("Cut") { Color = new Color(1) };
+                RapidLayer = new Layer("Rapid") { Color = new Color(5) };
+                PlateLayer = new Layer("Plate") { Color = new Color(4) };
+
+                Document.Layers.Add(CutLayer);
+                Document.Layers.Add(RapidLayer);
+                Document.Layers.Add(PlateLayer);
+            }
+
+            public void AddLine(XYZ start, XYZ end, Layer layer)
+            {
+                var ln = new AcadLine
+                {
+                    StartPoint = start,
+                    EndPoint = end,
+                    Layer = layer
+                };
+                Document.Entities.Add(ln);
+            }
+
+            public void AddPlateOutline(Plate plate)
+            {
+                XYZ pt1, pt2, pt3, pt4;
+
+                switch (plate.Quadrant)
+                {
+                    case 1:
+                        pt1 = new XYZ(0, 0, 0);
+                        pt2 = new XYZ(0, plate.Size.Width, 0);
+                        pt3 = new XYZ(plate.Size.Length, plate.Size.Width, 0);
+                        pt4 = new XYZ(plate.Size.Length, 0, 0);
+                        break;
+
+                    case 2:
+                        pt1 = new XYZ(0, 0, 0);
+                        pt2 = new XYZ(0, plate.Size.Width, 0);
+                        pt3 = new XYZ(-plate.Size.Length, plate.Size.Width, 0);
+                        pt4 = new XYZ(-plate.Size.Length, 0, 0);
+                        break;
+
+                    case 3:
+                        pt1 = new XYZ(0, 0, 0);
+                        pt2 = new XYZ(0, -plate.Size.Width, 0);
+                        pt3 = new XYZ(-plate.Size.Length, -plate.Size.Width, 0);
+                        pt4 = new XYZ(-plate.Size.Length, 0, 0);
+                        break;
+
+                    case 4:
+                        pt1 = new XYZ(0, 0, 0);
+                        pt2 = new XYZ(0, -plate.Size.Width, 0);
+                        pt3 = new XYZ(plate.Size.Length, -plate.Size.Width, 0);
+                        pt4 = new XYZ(plate.Size.Length, 0, 0);
+                        break;
+
+                    default:
+                        return;
+                }
+
+                AddLine(pt1, pt2, PlateLayer);
+                AddLine(pt2, pt3, PlateLayer);
+                AddLine(pt3, pt4, PlateLayer);
+                AddLine(pt4, pt1, PlateLayer);
+
+                var m1 = new XYZ(pt1.X + plate.EdgeSpacing.Left, pt1.Y + plate.EdgeSpacing.Bottom, 0);
+                var m2 = new XYZ(m1.X, pt2.Y - plate.EdgeSpacing.Top, 0);
+                var m3 = new XYZ(pt3.X - plate.EdgeSpacing.Right, m2.Y, 0);
+                var m4 = new XYZ(m3.X, m1.Y, 0);
+
+                AddLine(m1, m2, PlateLayer);
+                AddLine(m2, m3, PlateLayer);
+                AddLine(m3, m4, PlateLayer);
+                AddLine(m4, m1, PlateLayer);
+            }
+
+            public void AddProgram(Program program)
+            {
+                mode = program.Mode;
+
+                for (var i = 0; i < program.Length; ++i)
+                {
+                    var code = program[i];
+
+                    switch (code.Type)
+                    {
+                        case CodeType.ArcMove:
+                            AddArcMove((ArcMove)code);
+                            break;
+
+                        case CodeType.LinearMove:
+                            AddLinearMove((LinearMove)code);
+                            break;
+
+                        case CodeType.RapidMove:
+                            AddRapidMove((RapidMove)code);
+                            break;
+
+                        case CodeType.SubProgramCall:
+                            var tmpmode = mode;
+                            AddProgram(((SubProgramCall)code).Program);
+                            mode = tmpmode;
+                            break;
+                    }
+                }
+            }
+
+            private void AddLinearMove(LinearMove line)
+            {
+                var pt = line.EndPoint.ToAcadXYZ();
+
+                if (mode == Mode.Incremental)
+                    pt = new XYZ(pt.X + CurPos.X, pt.Y + CurPos.Y, 0);
+
+                AddLine(CurPos, pt, CutLayer);
+                CurPos = pt;
+            }
+
+            private void AddRapidMove(RapidMove rapid)
+            {
+                var pt = rapid.EndPoint.ToAcadXYZ();
+
+                if (mode == Mode.Incremental)
+                    pt = new XYZ(pt.X + CurPos.X, pt.Y + CurPos.Y, 0);
+
+                AddLine(CurPos, pt, RapidLayer);
+                CurPos = pt;
+            }
+
+            private void AddArcMove(ArcMove arc)
+            {
+                var center = arc.CenterPoint.ToAcadXYZ();
+                var endpt = arc.EndPoint.ToAcadXYZ();
+
+                if (mode == Mode.Incremental)
+                {
+                    endpt = new XYZ(endpt.X + CurPos.X, endpt.Y + CurPos.Y, 0);
+                    center = new XYZ(center.X + CurPos.X, center.Y + CurPos.Y, 0);
+                }
+
+                var startAngle = System.Math.Atan2(
+                    CurPos.Y - center.Y,
+                    CurPos.X - center.X);
+
+                var endAngle = System.Math.Atan2(
+                    endpt.Y - center.Y,
+                    endpt.X - center.X);
+
+                if (arc.Rotation == RotationType.CW)
+                    Generic.Swap(ref startAngle, ref endAngle);
+
+                var dx = endpt.X - center.X;
+                var dy = endpt.Y - center.Y;
+                var radius = System.Math.Sqrt(dx * dx + dy * dy);
+
+                if (startAngle.IsEqualTo(endAngle))
+                {
+                    var circle = new AcadCircle
+                    {
+                        Center = center,
+                        Radius = radius,
+                        Layer = CutLayer
+                    };
+                    Document.Entities.Add(circle);
+                }
+                else
+                {
+                    var acadArc = new AcadArc
+                    {
+                        Center = center,
+                        Radius = radius,
+                        StartAngle = startAngle,
+                        EndAngle = endAngle,
+                        Layer = CutLayer
+                    };
+                    Document.Entities.Add(acadArc);
+                }
+
+                CurPos = endpt;
+            }
+        }
+
+        #endregion
+    }
+}

OpenNest.IO/DxfExporter.cs

@@ -1,297 +0,0 @@
-using ACadSharp;
-using ACadSharp.IO;
-using CSMath;
-using OpenNest.CNC;
-using OpenNest.Math;
-using System.Diagnostics;
-using System.IO;
-
-namespace OpenNest.IO
-{
-    using AcadArc = ACadSharp.Entities.Arc;
-    using AcadCircle = ACadSharp.Entities.Circle;
-    using AcadLine = ACadSharp.Entities.Line;
-    using Layer = ACadSharp.Tables.Layer;
-
-    public class DxfExporter
-    {
-        private CadDocument doc;
-        private XYZ curpos;
-        private Mode mode;
-        private readonly Layer cutLayer;
-        private readonly Layer rapidLayer;
-        private readonly Layer plateLayer;
-
-        public DxfExporter()
-        {
-            doc = new CadDocument();
-
-            cutLayer = new Layer("Cut");
-            cutLayer.Color = new Color(1);
-
-            rapidLayer = new Layer("Rapid");
-            rapidLayer.Color = new Color(5);
-
-            plateLayer = new Layer("Plate");
-            plateLayer.Color = new Color(4);
-        }
-
-        public void ExportProgram(Program program, Stream stream)
-        {
-            doc = new CadDocument();
-            EnsureLayers();
-            AddProgram(program);
-            using (var writer = new DxfWriter(stream, doc, false))
-            {
-                writer.Write();
-            }
-        }
-
-        public bool ExportProgram(Program program, string path)
-        {
-            Stream stream = null;
-            var success = false;
-
-            try
-            {
-                stream = File.Create(path);
-                ExportProgram(program, stream);
-                success = true;
-            }
-            catch
-            {
-                Debug.Fail("DxfExporter.ExportProgram failed to write program to file: " + path);
-            }
-            finally
-            {
-                if (stream != null)
-                    stream.Close();
-            }
-
-            return success;
-        }
-
-        public void ExportPlate(Plate plate, Stream stream)
-        {
-            doc = new CadDocument();
-            EnsureLayers();
-            AddPlateOutline(plate);
-
-            foreach (var part in plate.Parts)
-            {
-                var endpt = part.Location.ToAcadXYZ();
-                AddLine(curpos, endpt, rapidLayer);
-                curpos = part.Location.ToAcadXYZ();
-                AddProgram(part.Program);
-            }
-
-            using (var writer = new DxfWriter(stream, doc, false))
-            {
-                writer.Write();
-            }
-        }
-
-        public bool ExportPlate(Plate plate, string path)
-        {
-            Stream stream = null;
-            var success = false;
-
-            try
-            {
-                stream = File.Create(path);
-                ExportPlate(plate, stream);
-                success = true;
-            }
-            catch
-            {
-                Debug.Fail("DxfExporter.ExportPlate failed to write plate to file: " + path);
-            }
-            finally
-            {
-                if (stream != null)
-                    stream.Close();
-            }
-
-            return success;
-        }
-
-        private void EnsureLayers()
-        {
-            doc.Layers.Add(cutLayer);
-            doc.Layers.Add(rapidLayer);
-            doc.Layers.Add(plateLayer);
-        }
-
-        private void AddLine(XYZ start, XYZ end, Layer layer)
-        {
-            var ln = new AcadLine();
-            ln.StartPoint = start;
-            ln.EndPoint = end;
-            ln.Layer = layer;
-            doc.Entities.Add(ln);
-        }
-
-        private void AddPlateOutline(Plate plate)
-        {
-            XYZ pt1;
-            XYZ pt2;
-            XYZ pt3;
-            XYZ pt4;
-
-            switch (plate.Quadrant)
-            {
-                case 1:
-                    pt1 = new XYZ(0, 0, 0);
-                    pt2 = new XYZ(0, plate.Size.Width, 0);
-                    pt3 = new XYZ(plate.Size.Length, plate.Size.Width, 0);
-                    pt4 = new XYZ(plate.Size.Length, 0, 0);
-                    break;
-
-                case 2:
-                    pt1 = new XYZ(0, 0, 0);
-                    pt2 = new XYZ(0, plate.Size.Width, 0);
-                    pt3 = new XYZ(-plate.Size.Length, plate.Size.Width, 0);
-                    pt4 = new XYZ(-plate.Size.Length, 0, 0);
-                    break;
-
-                case 3:
-                    pt1 = new XYZ(0, 0, 0);
-                    pt2 = new XYZ(0, -plate.Size.Width, 0);
-                    pt3 = new XYZ(-plate.Size.Length, -plate.Size.Width, 0);
-                    pt4 = new XYZ(-plate.Size.Length, 0, 0);
-                    break;
-
-                case 4:
-                    pt1 = new XYZ(0, 0, 0);
-                    pt2 = new XYZ(0, -plate.Size.Width, 0);
-                    pt3 = new XYZ(plate.Size.Length, -plate.Size.Width, 0);
-                    pt4 = new XYZ(plate.Size.Length, 0, 0);
-                    break;
-
-                default:
-                    return;
-            }
-
-            AddLine(pt1, pt2, plateLayer);
-            AddLine(pt2, pt3, plateLayer);
-            AddLine(pt3, pt4, plateLayer);
-            AddLine(pt4, pt1, plateLayer);
-
-            var m1 = new XYZ(pt1.X + plate.EdgeSpacing.Left, pt1.Y + plate.EdgeSpacing.Bottom, 0);
-            var m2 = new XYZ(m1.X, pt2.Y - plate.EdgeSpacing.Top, 0);
-            var m3 = new XYZ(pt3.X - plate.EdgeSpacing.Right, m2.Y, 0);
-            var m4 = new XYZ(m3.X, m1.Y, 0);
-
-            AddLine(m1, m2, plateLayer);
-            AddLine(m2, m3, plateLayer);
-            AddLine(m3, m4, plateLayer);
-            AddLine(m4, m1, plateLayer);
-        }
-
-        private void AddProgram(Program program)
-        {
-            mode = program.Mode;
-
-            for (var i = 0; i < program.Length; ++i)
-            {
-                var code = program[i];
-
-                switch (code.Type)
-                {
-                    case CodeType.ArcMove:
-                        var arc = (ArcMove)code;
-                        AddArcMove(arc);
-                        break;
-
-                    case CodeType.LinearMove:
-                        var line = (LinearMove)code;
-                        AddLinearMove(line);
-                        break;
-
-                    case CodeType.RapidMove:
-                        var rapid = (RapidMove)code;
-                        AddRapidMove(rapid);
-                        break;
-
-                    case CodeType.SubProgramCall:
-                        var tmpmode = mode;
-                        var subpgm = (CNC.SubProgramCall)code;
-                        AddProgram(subpgm.Program);
-                        mode = tmpmode;
-                        break;
-                }
-            }
-        }
-
-        private void AddLinearMove(LinearMove line)
-        {
-            var pt = line.EndPoint.ToAcadXYZ();
-
-            if (mode == Mode.Incremental)
-                pt = new XYZ(pt.X + curpos.X, pt.Y + curpos.Y, 0);
-
-            AddLine(curpos, pt, cutLayer);
-            curpos = pt;
-        }
-
-        private void AddRapidMove(RapidMove rapid)
-        {
-            var pt = rapid.EndPoint.ToAcadXYZ();
-
-            if (mode == Mode.Incremental)
-                pt = new XYZ(pt.X + curpos.X, pt.Y + curpos.Y, 0);
-
-            AddLine(curpos, pt, rapidLayer);
-            curpos = pt;
-        }
-
-        private void AddArcMove(ArcMove arc)
-        {
-            var center = arc.CenterPoint.ToAcadXYZ();
-            var endpt = arc.EndPoint.ToAcadXYZ();
-
-            if (mode == Mode.Incremental)
-            {
-                endpt = new XYZ(endpt.X + curpos.X, endpt.Y + curpos.Y, 0);
-                center = new XYZ(center.X + curpos.X, center.Y + curpos.Y, 0);
-            }
-
-            var startAngle = System.Math.Atan2(
-                curpos.Y - center.Y,
-                curpos.X - center.X);
-
-            var endAngle = System.Math.Atan2(
-                endpt.Y - center.Y,
-                endpt.X - center.X);
-
-            if (arc.Rotation == OpenNest.RotationType.CW)
-                Generic.Swap(ref startAngle, ref endAngle);
-
-            var dx = endpt.X - center.X;
-            var dy = endpt.Y - center.Y;
-
-            var radius = System.Math.Sqrt(dx * dx + dy * dy);
-
-            if (startAngle.IsEqualTo(endAngle))
-            {
-                var circle = new AcadCircle();
-                circle.Center = center;
-                circle.Radius = radius;
-                circle.Layer = cutLayer;
-                doc.Entities.Add(circle);
-            }
-            else
-            {
-                var arc2 = new AcadArc();
-                arc2.Center = center;
-                arc2.Radius = radius;
-                arc2.StartAngle = startAngle;
-                arc2.EndAngle = endAngle;
-                arc2.Layer = cutLayer;
-                doc.Entities.Add(arc2);
-            }
-
-            curpos = endpt;
-        }
-    }
-}

OpenNest.IO/DxfImporter.cs

@@ -1,155 +0,0 @@
-using ACadSharp;
-using ACadSharp.IO;
-using OpenNest.Geometry;
-using System;
-using System.Collections.Generic;
-using System.Diagnostics;
-using System.IO;
-
-namespace OpenNest.IO
-{
-    public class DxfImporter
-    {
-        public int SplinePrecision { get; set; }
-
-        public DxfImporter()
-        {
-        }
-
-        private List<Entity> GetGeometry(CadDocument doc)
-        {
-            var entities = new List<Entity>();
-            var lines = new List<Line>();
-            var arcs = new List<Arc>();
-
-            foreach (var entity in doc.Entities)
-            {
-                // Skip bend/etch entities — bends are converted to Bend objects
-                // separately via bend detection, and etch marks are generated from
-                // bends during DXF export. Neither should be treated as cut geometry.
-                if (IsNonCutLayer(entity.Layer?.Name))
-                    continue;
-
-                switch (entity)
-                {
-                    case ACadSharp.Entities.Line line:
-                        lines.Add(line.ToOpenNest());
-                        break;
-
-                    case ACadSharp.Entities.Arc arc:
-                        arcs.Add(arc.ToOpenNest());
-                        break;
-
-                    case ACadSharp.Entities.Circle circle:
-                        entities.Add(circle.ToOpenNest());
-                        break;
-
-                    case ACadSharp.Entities.Spline spline:
-                        foreach (var e in spline.ToOpenNest(SplinePrecision))
-                        {
-                            if (e is Line l) lines.Add(l);
-                            else if (e is Arc a) arcs.Add(a);
-                        }
-                        break;
-
-                    case ACadSharp.Entities.LwPolyline lwPolyline:
-                        lines.AddRange(lwPolyline.ToOpenNest());
-                        break;
-
-                    case ACadSharp.Entities.Polyline polyline:
-                        lines.AddRange(polyline.ToOpenNest());
-                        break;
-
-                    case ACadSharp.Entities.Ellipse ellipse:
-                        foreach (var e in ellipse.ToOpenNest())
-                        {
-                            if (e is Line l) lines.Add(l);
-                            else if (e is Arc a) arcs.Add(a);
-                        }
-                        break;
-                }
-            }
-
-            GeometryOptimizer.Optimize(lines);
-            GeometryOptimizer.Optimize(arcs);
-
-            entities.AddRange(lines);
-            entities.AddRange(arcs);
-
-            return entities;
-        }
-
-        /// <summary>
-        /// Imports a DXF file, returning both converted entities and the raw CadDocument
-        /// for bend detection. The CadDocument is NOT disposed — caller can use it for
-        /// additional analysis (e.g., MText extraction for bend notes).
-        /// </summary>
-        public DxfImportResult Import(string path)
-        {
-            using var reader = new DxfReader(path);
-            var doc = reader.Read();
-            var entities = GetGeometry(doc);
-
-            return new DxfImportResult
-            {
-                Entities = entities,
-                Document = doc
-            };
-        }
-
-        public bool GetGeometry(Stream stream, out List<Entity> geometry)
-        {
-            var success = false;
-
-            try
-            {
-                using (var reader = new DxfReader(stream))
-                {
-                    var doc = reader.Read();
-                    geometry = GetGeometry(doc);
-                    success = true;
-                }
-            }
-            catch (Exception ex)
-            {
-                Debug.WriteLine(ex.Message);
-                geometry = new List<Entity>();
-            }
-            finally
-            {
-                if (stream != null)
-                    stream.Close();
-            }
-
-            return success;
-        }
-
-        public bool GetGeometry(string path, out List<Entity> geometry)
-        {
-            var success = false;
-
-            try
-            {
-                using (var reader = new DxfReader(path))
-                {
-                    var doc = reader.Read();
-                    geometry = GetGeometry(doc);
-                    success = true;
-                }
-            }
-            catch (Exception ex)
-            {
-                Debug.WriteLine(ex.Message);
-                geometry = new List<Entity>();
-            }
-
-            return success;
-        }
-
-        private static bool IsNonCutLayer(string layerName)
-        {
-            return string.Equals(layerName, "BEND", System.StringComparison.OrdinalIgnoreCase)
-                || string.Equals(layerName, "ETCH", System.StringComparison.OrdinalIgnoreCase);
-        }
-    }
-}

OpenNest.IO/EntitySerializer.cs

@@ -0,0 +1,139 @@
+using OpenNest.Geometry;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using static OpenNest.IO.NestFormat;
+
+namespace OpenNest.IO
+{
+    public static class EntitySerializer
+    {
+        public static EntitySetDto ToDto(List<Entity> entities, HashSet<Guid> suppressed)
+        {
+            return new EntitySetDto
+            {
+                Entities = entities.Select(ToEntityDto).ToList(),
+                Suppressed = suppressed.Select(id => id.ToString()).ToList()
+            };
+        }
+
+        public static (List<Entity> entities, HashSet<Guid> suppressed) FromDto(EntitySetDto dto)
+        {
+            var entities = dto.Entities.Select(FromEntityDto).ToList();
+            var suppressed = new HashSet<Guid>(dto.Suppressed.Select(Guid.Parse));
+            return (entities, suppressed);
+        }
+
+        private static EntityDto ToEntityDto(Entity entity)
+        {
+            switch (entity.Type)
+            {
+                case EntityType.Line:
+                    var line = (Line)entity;
+                    return new EntityDto
+                    {
+                        Id = entity.Id.ToString(),
+                        Type = "line",
+                        Layer = entity.Layer?.Name ?? "",
+                        LineType = entity.LineTypeName ?? "",
+                        X1 = line.StartPoint.X,
+                        Y1 = line.StartPoint.Y,
+                        X2 = line.EndPoint.X,
+                        Y2 = line.EndPoint.Y
+                    };
+
+                case EntityType.Arc:
+                    var arc = (Arc)entity;
+                    return new EntityDto
+                    {
+                        Id = entity.Id.ToString(),
+                        Type = "arc",
+                        Layer = entity.Layer?.Name ?? "",
+                        LineType = entity.LineTypeName ?? "",
+                        CX = arc.Center.X,
+                        CY = arc.Center.Y,
+                        R = arc.Radius,
+                        StartAngle = arc.StartAngle,
+                        EndAngle = arc.EndAngle,
+                        Reversed = arc.IsReversed
+                    };
+
+                case EntityType.Circle:
+                    var circle = (Circle)entity;
+                    return new EntityDto
+                    {
+                        Id = entity.Id.ToString(),
+                        Type = "circle",
+                        Layer = entity.Layer?.Name ?? "",
+                        LineType = entity.LineTypeName ?? "",
+                        CX = circle.Center.X,
+                        CY = circle.Center.Y,
+                        R = circle.Radius,
+                        Rotation = circle.Rotation == RotationType.CW ? "CW" : "CCW"
+                    };
+
+                default:
+                    throw new NotSupportedException($"Entity type {entity.Type} is not supported for serialization.");
+            }
+        }
+
+        private static Entity FromEntityDto(EntityDto dto)
+        {
+            Entity entity;
+
+            switch (dto.Type)
+            {
+                case "line":
+                    entity = new Line(
+                        new Vector(dto.X1, dto.Y1),
+                        new Vector(dto.X2, dto.Y2));
+                    break;
+
+                case "arc":
+                    entity = new Arc(
+                        new Vector(dto.CX, dto.CY),
+                        dto.R,
+                        dto.StartAngle,
+                        dto.EndAngle,
+                        dto.Reversed);
+                    break;
+
+                case "circle":
+                    var circle = new Circle(new Vector(dto.CX, dto.CY), dto.R);
+                    circle.Rotation = dto.Rotation == "CW" ? RotationType.CW : RotationType.CCW;
+                    entity = circle;
+                    break;
+
+                default:
+                    throw new NotSupportedException($"Entity type '{dto.Type}' is not supported for deserialization.");
+            }
+
+            entity.Id = Guid.Parse(dto.Id);
+            entity.Layer = ResolveLayer(dto.Layer);
+            entity.LineTypeName = dto.LineType;
+
+            return entity;
+        }
+
+        private static Layer ResolveLayer(string name)
+        {
+            if (string.IsNullOrEmpty(name) || name == "0")
+                return Layer.Default;
+
+            if (string.Equals(name, SpecialLayers.Cut.Name, StringComparison.OrdinalIgnoreCase))
+                return SpecialLayers.Cut;
+            if (string.Equals(name, SpecialLayers.Rapid.Name, StringComparison.OrdinalIgnoreCase))
+                return SpecialLayers.Rapid;
+            if (string.Equals(name, SpecialLayers.Display.Name, StringComparison.OrdinalIgnoreCase))
+                return SpecialLayers.Display;
+            if (string.Equals(name, SpecialLayers.Leadin.Name, StringComparison.OrdinalIgnoreCase))
+                return SpecialLayers.Leadin;
+            if (string.Equals(name, SpecialLayers.Leadout.Name, StringComparison.OrdinalIgnoreCase))
+                return SpecialLayers.Leadout;
+            if (string.Equals(name, SpecialLayers.Scribe.Name, StringComparison.OrdinalIgnoreCase))
+                return SpecialLayers.Scribe;
+
+            return new Layer(name);
+        }
+    }
+}

OpenNest.IO/Extensions.cs

@@ -57,7 +57,7 @@ namespace OpenNest.IO
             return result;
         }
 
-        public static List<Geometry.Entity> ToOpenNest(this Spline spline, int precision)
+        public static List<Geometry.Entity> ToOpenNest(this Spline spline)
         {
             var layer = spline.Layer.ToOpenNest();
             var color = spline.ResolveColor();
@@ -67,7 +67,7 @@ namespace OpenNest.IO
             List<XYZ> curvePoints;
             try
             {
-                curvePoints = spline.PolygonalVertexes(precision > 0 ? precision : 200);
+                curvePoints = spline.PolygonalVertexes(200);
             }
             catch (Exception ex)
             {

OpenNest.IO/NestFormat.cs

@@ -162,6 +162,35 @@ namespace OpenNest.IO
             public double Cost { get; init; }
         }
 
+        public record EntitySetDto
+        {
+            public List<EntityDto> Entities { get; init; } = new();
+            public List<string> Suppressed { get; init; } = new();
+        }
+
+        public record EntityDto
+        {
+            public string Id { get; init; } = "";
+            public string Type { get; init; } = "";
+            public string Layer { get; init; } = "";
+            public string LineType { get; init; } = "";
+
+            // Line
+            public double X1 { get; init; }
+            public double Y1 { get; init; }
+            public double X2 { get; init; }
+            public double Y2 { get; init; }
+
+            // Arc / Circle
+            public double CX { get; init; }
+            public double CY { get; init; }
+            public double R { get; init; }
+            public double StartAngle { get; init; }
+            public double EndAngle { get; init; }
+            public bool Reversed { get; init; }
+            public string Rotation { get; init; } = "";
+        }
+
         public record BestFitSetDto
         {
             public double PlateWidth { get; init; }

OpenNest.IO/NestReader.cs

@@ -36,7 +36,8 @@ namespace OpenNest.IO
             var dto = JsonSerializer.Deserialize<NestDto>(nestJson, JsonOptions);
 
             var programs = ReadPrograms(dto.Drawings.Count);
-            var drawingMap = BuildDrawings(dto, programs);
+            var entitySets = ReadEntitySets(dto.Drawings.Count);
+            var drawingMap = BuildDrawings(dto, programs, entitySets);
             ReadBestFits(drawingMap);
             var nest = BuildNest(dto, drawingMap);
 
@@ -74,7 +75,25 @@ namespace OpenNest.IO
             return programs;
         }
 
-        private Dictionary<int, Drawing> BuildDrawings(NestDto dto, Dictionary<int, Program> programs)
+        private Dictionary<int, (List<Entity> entities, HashSet<Guid> suppressed)> ReadEntitySets(int count)
+        {
+            var result = new Dictionary<int, (List<Entity>, HashSet<Guid>)>();
+            for (var i = 1; i <= count; i++)
+            {
+                var entry = zipArchive.GetEntry($"entities/entities-{i}");
+                if (entry == null) continue;
+
+                using var entryStream = entry.Open();
+                using var reader = new StreamReader(entryStream);
+                var json = reader.ReadToEnd();
+                var dto = JsonSerializer.Deserialize<EntitySetDto>(json, JsonOptions);
+                result[i] = EntitySerializer.FromDto(dto);
+            }
+            return result;
+        }
+
+        private Dictionary<int, Drawing> BuildDrawings(NestDto dto, Dictionary<int, Program> programs,
+            Dictionary<int, (List<Entity> entities, HashSet<Guid> suppressed)> entitySets)
         {
             var map = new Dictionary<int, Drawing>();
             foreach (var d in dto.Drawings)
@@ -112,6 +131,12 @@ namespace OpenNest.IO
                 if (programs.TryGetValue(d.Id, out var pgm))
                     drawing.Program = pgm;
 
+                if (entitySets.TryGetValue(d.Id, out var entitySet))
+                {
+                    drawing.SourceEntities = entitySet.entities;
+                    drawing.SuppressedEntityIds = entitySet.suppressed;
+                }
+
                 map[d.Id] = drawing;
             }
             return map;

OpenNest.IO/NestWriter.cs

@@ -41,6 +41,7 @@ namespace OpenNest.IO
 
             WriteNestJson(zipArchive);
             WritePrograms(zipArchive);
+            WriteEntities(zipArchive);
             WriteBestFits(zipArchive);
 
             return true;
@@ -312,6 +313,24 @@ namespace OpenNest.IO
             }
         }
 
+        private void WriteEntities(ZipArchive zipArchive)
+        {
+            foreach (var kvp in drawingDict.OrderBy(k => k.Key))
+            {
+                var drawing = kvp.Value;
+                if (drawing.SourceEntities == null || drawing.SourceEntities.Count == 0)
+                    continue;
+
+                var dto = EntitySerializer.ToDto(drawing.SourceEntities, drawing.SuppressedEntityIds);
+                var json = JsonSerializer.Serialize(dto, JsonOptions);
+
+                var entry = zipArchive.CreateEntry($"entities/entities-{kvp.Key}");
+                using var stream = entry.Open();
+                using var writer = new StreamWriter(stream, Encoding.UTF8);
+                writer.Write(json);
+            }
+        }
+
         private void WriteDrawing(Stream stream, Drawing drawing)
         {
             var program = drawing.Program;

OpenNest.Mcp/Tools/InputTools.cs

@@ -96,13 +96,10 @@ namespace OpenNest.Mcp.Tools
             if (!File.Exists(path))
                 return $"Error: file not found: {path}";
 
-            var importer = new DxfImporter();
-
-            if (!importer.GetGeometry(path, out var geometry))
-                return "Error: failed to read DXF file";
+            var geometry = Dxf.GetGeometry(path);
 
             if (geometry.Count == 0)
-                return "Error: no geometry found in DXF file";
+                return "Error: failed to read DXF file or no geometry found";
 
             var normalized = ShapeProfile.NormalizeEntities(geometry);
             var pgm = ConvertGeometry.ToProgram(normalized);

OpenNest.Tests/Api/NestRunnerTests.cs

@@ -70,8 +70,7 @@ public class NestRunnerTests
         var pgm = ConvertGeometry.ToProgram(shape);
         var path = Path.Combine(Path.GetTempPath(), $"test-{Guid.NewGuid()}.dxf");
 
-        var exporter = new DxfExporter();
-        exporter.ExportProgram(pgm, path);
+        Dxf.ExportProgram(pgm, path);
 
         return path;
     }

OpenNest.Tests/Bending/SolidWorksBendDetectorTests.cs

@@ -35,8 +35,7 @@ public class SolidWorksBendDetectorTests
         var path = Path.Combine(AppContext.BaseDirectory, "Bending", "TestData", "4526 A14 PT11 Test.dxf");
         Assert.True(File.Exists(path), $"Test DXF not found: {path}");
 
-        var importer = new OpenNest.IO.DxfImporter { SplinePrecision = 200 };
-        var result = importer.Import(path);
+        var result = OpenNest.IO.Dxf.Import(path);
 
         // EllipseConverter now produces arcs directly during import,
         // so the imported entities should contain Arc instances from the ellipses
@@ -61,8 +60,7 @@ public class SolidWorksBendDetectorTests
         var path = Path.Combine(AppContext.BaseDirectory, "Bending", "TestData", "4526 A14 PT11.dxf");
         Assert.True(File.Exists(path), $"Test DXF not found: {path}");
 
-        var importer = new OpenNest.IO.DxfImporter();
-        var result = importer.Import(path);
+        var result = OpenNest.IO.Dxf.Import(path);
 
         // The DXF has 2 trimmed ellipses forming an oblong slot.
         // Trimmed ellipses must not generate a closing chord line.

OpenNest.Tests/BestFit/BestFitOverlapTests.cs

@@ -32,8 +32,7 @@ public class BestFitOverlapTests
         if (!File.Exists(DxfPath))
             return null;
 
-        var importer = new DxfImporter();
-        importer.GetGeometry(DxfPath, out var geometry);
+        var geometry = Dxf.GetGeometry(DxfPath);
         var pgm = ConvertGeometry.ToProgram(geometry);
         return new Drawing("PT16", pgm);
     }

OpenNest.Tests/Engine/EngineOverlapTests.cs

@@ -20,8 +20,7 @@ public class EngineOverlapTests
         if (!System.IO.File.Exists(DxfPath))
             return null;
 
-        var importer = new DxfImporter();
-        importer.GetGeometry(DxfPath, out var geometry);
+        var geometry = Dxf.GetGeometry(DxfPath);
         var pgm = ConvertGeometry.ToProgram(geometry);
         return new Drawing("PT15", pgm);
     }

OpenNest.Tests/Engine/MultiPlateNesterTests.cs

@@ -0,0 +1,411 @@
+using OpenNest.Geometry;
+using OpenNest.IO;
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Threading;
+using Xunit;
+using Xunit.Abstractions;
+
+namespace OpenNest.Tests.Engine;
+
+public class MultiPlateNesterTests
+{
+    private readonly ITestOutputHelper _output;
+
+    public MultiPlateNesterTests(ITestOutputHelper output)
+    {
+        _output = output;
+    }
+    private static Drawing MakeDrawing(string name, double width, double length)
+    {
+        var program = new OpenNest.CNC.Program();
+        program.Codes.Add(new OpenNest.CNC.RapidMove(new Vector(0, 0)));
+        program.Codes.Add(new OpenNest.CNC.LinearMove(new Vector(width, 0)));
+        program.Codes.Add(new OpenNest.CNC.LinearMove(new Vector(width, length)));
+        program.Codes.Add(new OpenNest.CNC.LinearMove(new Vector(0, length)));
+        program.Codes.Add(new OpenNest.CNC.LinearMove(new Vector(0, 0)));
+        var drawing = new Drawing(name, program);
+        drawing.UpdateArea();
+        return drawing;
+    }
+
+    private static NestItem MakeItem(string name, double width, double length, int qty = 1)
+    {
+        return new NestItem
+        {
+            Drawing = MakeDrawing(name, width, length),
+            Quantity = qty,
+        };
+    }
+
+    [Fact]
+    public void SortByBoundingBoxArea_OrdersLargestFirst()
+    {
+        var items = new List<NestItem>
+        {
+            MakeItem("small", 10, 10),
+            MakeItem("large", 40, 60),
+            MakeItem("medium", 20, 30),
+        };
+
+        var sorted = MultiPlateNester.SortItems(items, PartSortOrder.BoundingBoxArea);
+
+        Assert.Equal("large", sorted[0].Drawing.Name);
+        Assert.Equal("medium", sorted[1].Drawing.Name);
+        Assert.Equal("small", sorted[2].Drawing.Name);
+    }
+
+    [Fact]
+    public void SortBySize_OrdersByLongestDimension()
+    {
+        var items = new List<NestItem>
+        {
+            MakeItem("short-wide", 50, 20),    // longest = 50
+            MakeItem("tall-narrow", 10, 80),    // longest = 80
+            MakeItem("square", 30, 30),         // longest = 30
+        };
+
+        var sorted = MultiPlateNester.SortItems(items, PartSortOrder.Size);
+
+        Assert.Equal("tall-narrow", sorted[0].Drawing.Name);
+        Assert.Equal("short-wide", sorted[1].Drawing.Name);
+        Assert.Equal("square", sorted[2].Drawing.Name);
+    }
+
+    // --- Task 4: Part Classification ---
+
+    [Fact]
+    public void Classify_LargePart_WhenWidthExceedsHalfWorkArea()
+    {
+        var workArea = new Box(0, 0, 96, 48);
+        var bb = new Box(0, 0, 50, 20); // width 50 > half of 96 = 48
+        var result = MultiPlateNester.Classify(bb, workArea);
+        Assert.Equal(PartClass.Large, result);
+    }
+
+    [Fact]
+    public void Classify_LargePart_WhenLengthExceedsHalfWorkArea()
+    {
+        var workArea = new Box(0, 0, 96, 48);
+        var bb = new Box(0, 0, 20, 30); // length 30 > half of 48 = 24
+        var result = MultiPlateNester.Classify(bb, workArea);
+        Assert.Equal(PartClass.Large, result);
+    }
+
+    [Fact]
+    public void Classify_MediumPart_NotLargeButAreaAboveThreshold()
+    {
+        var workArea = new Box(0, 0, 96, 48);
+        // workArea = 4608, 1/9 = 512. bb = 40*15 = 600 > 512
+        // 40 < 48 (half of 96), 15 < 24 (half of 48) — not Large
+        var bb = new Box(0, 0, 40, 15);
+        var result = MultiPlateNester.Classify(bb, workArea);
+        Assert.Equal(PartClass.Medium, result);
+    }
+
+    [Fact]
+    public void Classify_SmallPart()
+    {
+        var workArea = new Box(0, 0, 96, 48);
+        // workArea = 4608, 1/9 = 512. bb = 10*10 = 100 < 512
+        var bb = new Box(0, 0, 10, 10);
+        var result = MultiPlateNester.Classify(bb, workArea);
+        Assert.Equal(PartClass.Small, result);
+    }
+
+    // --- Task 5: Scrap Zone Identification ---
+
+    [Fact]
+    public void IsScrapRemnant_BothDimensionsBelowThreshold_ReturnsTrue()
+    {
+        var remnant = new Box(0, 0, 10, 8);
+        Assert.True(MultiPlateNester.IsScrapRemnant(remnant, 12.0));
+    }
+
+    [Fact]
+    public void IsScrapRemnant_OneDimensionAboveThreshold_ReturnsFalse()
+    {
+        // 11 x 120 — narrow but long, should be preserved
+        var remnant = new Box(0, 0, 11, 120);
+        Assert.False(MultiPlateNester.IsScrapRemnant(remnant, 12.0));
+    }
+
+    [Fact]
+    public void IsScrapRemnant_BothDimensionsAboveThreshold_ReturnsFalse()
+    {
+        var remnant = new Box(0, 0, 20, 30);
+        Assert.False(MultiPlateNester.IsScrapRemnant(remnant, 12.0));
+    }
+
+    [Fact]
+    public void FindRemnants_ScrapOnly_ReturnsOnlyScrapRemnants()
+    {
+        // 96x48 plate with a 70x40 part placed at origin
+        var plate = new Plate(96, 48) { PartSpacing = 0.25 };
+        var drawing = MakeDrawing("big", 70, 40);
+        var part = new Part(drawing);
+        plate.Parts.Add(part);
+
+        var scrap = MultiPlateNester.FindRemnants(plate, 12.0, scrapOnly: true);
+
+        // All returned zones should have both dims < 12
+        foreach (var zone in scrap)
+        {
+            Assert.True(zone.Width < 12.0 && zone.Length < 12.0,
+                $"Zone {zone.Width:F1}x{zone.Length:F1} is not scrap — at least one dimension >= 12");
+        }
+    }
+
+    // --- Task 6: Plate Creation Helper ---
+
+    [Fact]
+    public void CreatePlate_UsesTemplateWhenNoOptions()
+    {
+        var template = new Plate(96, 48) { PartSpacing = 0.25, Quadrant = 1 };
+        template.EdgeSpacing = new Spacing { Left = 1, Right = 1, Top = 1, Bottom = 1 };
+
+        var plate = MultiPlateNester.CreatePlate(template, null, null);
+
+        Assert.Equal(96, plate.Size.Width);
+        Assert.Equal(48, plate.Size.Length);
+        Assert.Equal(0.25, plate.PartSpacing);
+        Assert.Equal(1, plate.Quadrant);
+    }
+
+    [Fact]
+    public void CreatePlate_PicksSmallestFittingOption()
+    {
+        var template = new Plate(96, 48) { PartSpacing = 0.25, Quadrant = 1 };
+        template.EdgeSpacing = new Spacing { Left = 1, Right = 1, Top = 1, Bottom = 1 };
+
+        var options = new List<PlateOption>
+        {
+            new() { Width = 48, Length = 96, Cost = 100 },
+            new() { Width = 60, Length = 120, Cost = 200 },
+            new() { Width = 72, Length = 144, Cost = 300 },
+        };
+
+        // Part needs 50x50 work area — 48x96 (after edge spacing: 46x94) — 46 < 50, doesn't fit.
+        // 60x120 (58x118) does fit.
+        var minBounds = new Box(0, 0, 50, 50);
+
+        var plate = MultiPlateNester.CreatePlate(template, options, minBounds);
+
+        Assert.Equal(60, plate.Size.Width);
+        Assert.Equal(120, plate.Size.Length);
+    }
+
+    [Fact]
+    public void EvaluateUpgrade_PrefersCheaperOption()
+    {
+        var currentOption = new PlateOption { Width = 48, Length = 96, Cost = 100 };
+        var upgradeOption = new PlateOption { Width = 60, Length = 120, Cost = 160 };
+        var newPlateOption = new PlateOption { Width = 48, Length = 96, Cost = 100 };
+
+        // Upgrade cost = 160 - 100 = 60
+        // New plate cost with 50% utilization, 50% salvage:
+        // remnantFraction = 0.5, salvageCredit = 0.5 * 100 * 0.5 = 25
+        // netNewCost = 100 - 25 = 75
+        // Upgrade (60) < new plate (75), so upgrade wins
+        var decision = MultiPlateNester.EvaluateUpgradeVsNew(
+            currentOption, upgradeOption, newPlateOption, 0.5, 0.5);
+
+        Assert.True(decision.ShouldUpgrade);
+    }
+
+    // --- Task 7: Main Orchestration ---
+
+    [Fact]
+    public void Nest_LargePartsGetOwnPlates()
+    {
+        var template = new Plate(96, 48) { PartSpacing = 0.25, Quadrant = 1 };
+        template.EdgeSpacing = new Spacing();
+
+        var items = new List<NestItem>
+        {
+            MakeItem("big1", 80, 40, 1),
+            MakeItem("big2", 70, 35, 1),
+        };
+
+        var options = new MultiPlateNestOptions { Template = template };
+
+        var result = MultiPlateNester.Nest(items, options);
+
+        // Each large part should be on its own plate.
+        Assert.True(result.Plates.Count >= 2,
+            $"Expected at least 2 plates, got {result.Plates.Count}");
+    }
+
+    [Fact]
+    public void Nest_SmallPartsConsolidateOntoSharedPlates()
+    {
+        // Small parts should be packed together on shared plates rather than
+        // each drawing getting its own plate. The consolidation pass fills
+        // small parts into remaining space on existing plates.
+        var template = new Plate(96, 48) { PartSpacing = 0.25, Quadrant = 1 };
+        template.EdgeSpacing = new Spacing();
+
+        var items = new List<NestItem>
+        {
+            MakeItem("big", 80, 40, 1),
+            MakeItem("tinyA", 5, 5, 3),
+            MakeItem("tinyB", 4, 4, 3),
+        };
+
+        var options = new MultiPlateNestOptions { Template = template };
+
+        var result = MultiPlateNester.Nest(items, options);
+
+        // Both small drawing types should share space — not each on their own plate.
+        // With consolidation, they pack into remaining space alongside the big part.
+        Assert.True(result.Plates.Count <= 2,
+            $"Expected at most 2 plates (small parts consolidated), got {result.Plates.Count}");
+        Assert.Equal(0, result.UnplacedItems.Count);
+    }
+
+    [Fact]
+    public void Nest_RespectsAllowPlateCreation()
+    {
+        var template = new Plate(96, 48) { PartSpacing = 0.25, Quadrant = 1 };
+        template.EdgeSpacing = new Spacing();
+
+        var items = new List<NestItem>
+        {
+            MakeItem("big1", 80, 40, 1),
+            MakeItem("big2", 70, 35, 1),
+        };
+
+        var options = new MultiPlateNestOptions
+        {
+            Template = template,
+            AllowPlateCreation = false,
+        };
+
+        var result = MultiPlateNester.Nest(items, options);
+
+        // No existing plates and no plate creation — nothing can be placed.
+        Assert.Empty(result.Plates);
+        Assert.Equal(2, result.UnplacedItems.Count);
+    }
+
+    [Fact]
+    public void Nest_UsesExistingPlates()
+    {
+        var template = new Plate(96, 48) { PartSpacing = 0.25, Quadrant = 1 };
+        template.EdgeSpacing = new Spacing();
+
+        var existingPlate = new Plate(96, 48) { PartSpacing = 0.25, Quadrant = 1 };
+        existingPlate.EdgeSpacing = new Spacing();
+
+        // Use a part small enough to be classified as Medium on a 96x48 plate.
+        // Plate WorkArea: Width=96, Length=48. Half: 48, 24.
+        // Part 24x22: Length=24 (not > 24), Width=22 (not > 48) — not Large.
+        // Area = 528 > 4608/9 = 512 — Medium.
+        var items = new List<NestItem>
+        {
+            MakeItem("medium", 24, 22, 1),
+        };
+
+        var options = new MultiPlateNestOptions { Template = template };
+
+        var result = MultiPlateNester.Nest(items, options,
+            existingPlates: new List<Plate> { existingPlate });
+
+        // Part should be placed on the existing plate, not a new one.
+        Assert.Single(result.Plates);
+        Assert.False(result.Plates[0].IsNew);
+    }
+
+    [Fact]
+    public void Nest_RealNestFile_PartFirst()
+    {
+        var nestPath = @"C:\Users\aisaacs\Desktop\4526 A14 - 0.188 AISI 304.nest";
+        if (!File.Exists(nestPath))
+        {
+            _output.WriteLine("SKIP: nest file not found");
+            return;
+        }
+
+        var nest = new NestReader(nestPath).Read();
+        var template = nest.PlateDefaults.CreateNew();
+
+        _output.WriteLine($"Plate: {template.Size.Width}x{template.Size.Length}, " +
+            $"spacing={template.PartSpacing}, edge=({template.EdgeSpacing.Left},{template.EdgeSpacing.Bottom},{template.EdgeSpacing.Right},{template.EdgeSpacing.Top})");
+
+        var wa = template.WorkArea();
+        _output.WriteLine($"Work area: {wa.Width:F1}x{wa.Length:F1}");
+        _output.WriteLine($"Classification thresholds: Large if dim > {wa.Width / 2:F1} or {wa.Length / 2:F1}, " +
+            $"Medium if area > {wa.Width * wa.Length / 9:F0}");
+        _output.WriteLine("---");
+
+        var items = new List<NestItem>();
+        foreach (var d in nest.Drawings)
+        {
+            var qty = d.Quantity.Required > 0 ? d.Quantity.Required : d.Quantity.Remaining;
+            if (qty <= 0) qty = 1;
+
+            var bb = d.Program.BoundingBox();
+            var classification = MultiPlateNester.Classify(bb, wa);
+
+            _output.WriteLine($"  {d.Name,-25} {bb.Width:F1}x{bb.Length:F1} (area={bb.Width * bb.Length:F0})  qty={qty}  class={classification}");
+
+            items.Add(new NestItem
+            {
+                Drawing = d,
+                Quantity = qty,
+                StepAngle = d.Constraints.StepAngle,
+                RotationStart = d.Constraints.StartAngle,
+                RotationEnd = d.Constraints.EndAngle,
+            });
+        }
+
+        _output.WriteLine("---");
+        _output.WriteLine($"Total: {items.Count} drawings, {items.Sum(i => i.Quantity)} parts");
+
+        var plateOptions = new List<PlateOption>
+        {
+            new() { Width = 48, Length = 96, Cost = 0 },
+            new() { Width = 48, Length = 120, Cost = 0 },
+            new() { Width = 48, Length = 144, Cost = 0 },
+            new() { Width = 60, Length = 96, Cost = 0 },
+            new() { Width = 60, Length = 120, Cost = 0 },
+            new() { Width = 60, Length = 144, Cost = 0 },
+            new() { Width = 72, Length = 96, Cost = 0 },
+            new() { Width = 72, Length = 120, Cost = 0 },
+            new() { Width = 72, Length = 144, Cost = 0 },
+        };
+
+        _output.WriteLine($"Plate options: {string.Join(", ", plateOptions.Select(o => $"{o.Width}x{o.Length}"))}");
+        _output.WriteLine("");
+
+        var options = new MultiPlateNestOptions
+        {
+            Template = template,
+            PlateOptions = plateOptions,
+        };
+
+        var result = MultiPlateNester.Nest(items, options);
+
+        _output.WriteLine($"=== RESULTS: {result.Plates.Count} plates ===");
+
+        for (var i = 0; i < result.Plates.Count; i++)
+        {
+            var pr = result.Plates[i];
+            var groups = pr.Parts.GroupBy(p => p.BaseDrawing.Name)
+                .Select(g => $"{g.Key} x{g.Count()}")
+                .ToList();
+            _output.WriteLine($"  Plate {i + 1} ({pr.Plate.Size.Width}x{pr.Plate.Size.Length}): " +
+                $"{pr.Parts.Count} parts, util={pr.Plate.Utilization():P1}  [{string.Join(", ", groups)}]");
+        }
+
+        if (result.UnplacedItems.Count > 0)
+        {
+            _output.WriteLine($"  Unplaced: {string.Join(", ", result.UnplacedItems.Select(i => $"{i.Drawing.Name} x{i.Quantity}"))}");
+        }
+
+        _output.WriteLine($"\nTotal parts placed: {result.Plates.Sum(p => p.Parts.Count)}");
+        _output.WriteLine($"Total plates used: {result.Plates.Count}");
+    }
+}

OpenNest.Tests/Fill/FillLinearCircleTests.cs

@@ -0,0 +1,130 @@
+using OpenNest;
+using OpenNest.CNC;
+using OpenNest.Converters;
+using OpenNest.Engine.Fill;
+using OpenNest.Geometry;
+using OpenNest.Math;
+using Xunit;
+using Xunit.Abstractions;
+using System.Collections.Generic;
+using System.Linq;
+
+namespace OpenNest.Tests.Fill
+{
+    public class FillLinearCircleTests
+    {
+        private readonly ITestOutputHelper _output;
+
+        public FillLinearCircleTests(ITestOutputHelper output) => _output = output;
+
+        private static Drawing MakeCircleDrawing(double radius)
+        {
+            var pgm = new Program();
+            var startPt = new Vector(radius * 2, radius); // rightmost point
+            pgm.Codes.Add(new RapidMove(startPt));
+            pgm.Codes.Add(new ArcMove(startPt, new Vector(radius, radius), RotationType.CCW));
+            return new Drawing("circle", pgm);
+        }
+
+        private static Drawing MakeRingDrawing(double outerRadius, double innerRadius)
+        {
+            var pgm = new Program();
+            // Outer circle (CCW)
+            var outerStart = new Vector(outerRadius * 2, outerRadius);
+            pgm.Codes.Add(new RapidMove(outerStart));
+            pgm.Codes.Add(new ArcMove(outerStart, new Vector(outerRadius, outerRadius), RotationType.CCW));
+            // Inner circle (CW = hole)
+            var innerStart = new Vector(outerRadius + innerRadius, outerRadius);
+            pgm.Codes.Add(new RapidMove(innerStart));
+            pgm.Codes.Add(new ArcMove(innerStart, new Vector(outerRadius, outerRadius), RotationType.CW));
+            return new Drawing("ring", pgm);
+        }
+
+        [Theory]
+        [InlineData(2.0, 0.125)]   // 4" diameter circle, 1/8" spacing
+        [InlineData(1.0, 0.125)]   // 2" diameter circle
+        [InlineData(3.0, 0.0625)]  // 6" diameter circle, 1/16" spacing
+        [InlineData(0.5, 0.25)]    // 1" diameter circle, 1/4" spacing
+        public void CircleFill_OffsetBoundaries_DoNotOverlap(double radius, double spacing)
+        {
+            var drawing = MakeCircleDrawing(radius);
+            var workArea = new Box(0, 0, 48, 48);
+            var engine = new FillLinear(workArea, spacing);
+            var parts = engine.Fill(drawing, 0, NestDirection.Horizontal);
+
+            _output.WriteLine($"Circle R={radius}, spacing={spacing}: {parts.Count} parts");
+
+            AssertNoOffsetOverlap(parts, spacing, radius * 2);
+        }
+
+        [Theory]
+        [InlineData(2.0, 1.5, 0.125)]  // Ring: outer R=2, inner R=1.5
+        [InlineData(1.5, 1.0, 0.125)]  // Ring: outer R=1.5, inner R=1.0
+        public void RingFill_OffsetBoundaries_DoNotOverlap(double outerR, double innerR, double spacing)
+        {
+            var drawing = MakeRingDrawing(outerR, innerR);
+            var workArea = new Box(0, 0, 48, 48);
+            var engine = new FillLinear(workArea, spacing);
+            var parts = engine.Fill(drawing, 0, NestDirection.Horizontal);
+
+            _output.WriteLine($"Ring outerR={outerR}, innerR={innerR}, spacing={spacing}: {parts.Count} parts");
+
+            AssertNoOffsetOverlap(parts, spacing, outerR * 2);
+        }
+
+        private void AssertNoOffsetOverlap(List<Part> parts, double spacing, double expectedDiameter)
+        {
+            if (parts.Count < 2)
+            {
+                _output.WriteLine("  Only 1 part placed, skipping overlap check");
+                return;
+            }
+
+            var halfSpacing = spacing / 2;
+            var radius = expectedDiameter / 2;
+            var minGap = double.MaxValue;
+            var violationCount = 0;
+
+            // For circular parts, the center is at Location + (radius, radius).
+            for (var i = 0; i < parts.Count; i++)
+            {
+                var ci = parts[i].Location + new Vector(radius, radius);
+
+                for (var j = i + 1; j < parts.Count; j++)
+                {
+                    var cj = parts[j].Location + new Vector(radius, radius);
+                    var centerDist = ci.DistanceTo(cj);
+
+                    // Gap between raw circle perimeters
+                    var rawGap = centerDist - expectedDiameter;
+
+                    // Gap between offset circle perimeters (halfSpacing each side)
+                    var offsetGap = centerDist - expectedDiameter - spacing;
+
+                    if (rawGap < minGap)
+                        minGap = rawGap;
+
+                    if (rawGap < spacing - Tolerance.Epsilon)
+                    {
+                        violationCount++;
+                        if (violationCount <= 5)
+                        {
+                            _output.WriteLine($"  SPACING VIOLATION parts[{i}] vs parts[{j}]: " +
+                                $"centerDist={centerDist:F6}, rawGap={rawGap:F6}, offsetGap={offsetGap:F6}, " +
+                                $"expected>={spacing:F4}");
+                        }
+                    }
+                }
+            }
+
+            _output.WriteLine($"  Min gap={minGap:F6}, expected>={spacing:F4}, violations={violationCount}");
+
+            if (violationCount > 0)
+            {
+                var maxDeficit = spacing - minGap;
+                _output.WriteLine($"  Max deficit={maxDeficit:F6}");
+                Assert.Fail($"{violationCount} pairs violate spacing: min gap={minGap:F6}, expected>={spacing}, deficit={maxDeficit:F6}");
+            }
+        }
+    }
+}

OpenNest.Tests/Geometry/ContourClassificationTests.cs

@@ -154,4 +154,18 @@ public class ContourClassificationTests
 
         Assert.NotEqual(originalDirection, newDirection);
     }
+
+    [Fact]
+    public void Reverse_changes_direction_label_for_circle()
+    {
+        var shape = MakeCircleShape(0, 0, 10);
+        var contours = ContourInfo.Classify(new List<Shape> { shape });
+        var contour = contours[0];
+
+        var originalDirection = contour.DirectionLabel;
+        contour.Reverse();
+        var newDirection = contour.DirectionLabel;
+
+        Assert.NotEqual(originalDirection, newDirection);
+    }
 }

OpenNest.Tests/Geometry/EllipseConverterTests.cs

@@ -228,8 +228,7 @@ public class EllipseConverterTests
             using (var writer = new ACadSharp.IO.DxfWriter(stream, doc, false))
                 writer.Write();
 
-            var importer = new OpenNest.IO.DxfImporter { SplinePrecision = 200 };
-            var result = importer.Import(tempPath);
+            var result = OpenNest.IO.Dxf.Import(tempPath);
 
             var arcCount = result.Entities.Count(e => e is Arc);
             var lineCount = result.Entities.Count(e => e is Line);

OpenNest.Tests/Geometry/GeometrySimplifierTests.cs

@@ -138,8 +138,7 @@ public class GeometrySimplifierTests
         if (!File.Exists(path))
             return; // skip if file not available
 
-        var importer = new DxfImporter();
-        var result = importer.Import(path);
+        var result = Dxf.Import(path);
         var shapes = ShapeBuilder.GetShapes(result.Entities);
 
         var simplifier = new GeometrySimplifier { Tolerance = 0.004 };

OpenNest.Tests/Geometry/SpatialQueryTests.cs

@@ -0,0 +1,349 @@
+using OpenNest.Geometry;
+using OpenNest.Math;
+using System.Collections.Generic;
+
+namespace OpenNest.Tests.Geometry;
+
+public class SpatialQueryTests
+{
+    #region Helpers
+
+    private static List<Entity> MakeSquare(double size)
+    {
+        return new List<Entity>
+        {
+            new Line(0, 0, size, 0),
+            new Line(size, 0, size, size),
+            new Line(size, size, 0, size),
+            new Line(0, size, 0, 0),
+        };
+    }
+
+    private static List<Entity> MakeRoundedRect(double length, double width, double r)
+    {
+        return new List<Entity>
+        {
+            new Line(r, 0, length - r, 0),
+            new Arc(length - r, r, r, Angle.ToRadians(270), Angle.ToRadians(360)),
+            new Line(length, r, length, width - r),
+            new Arc(length - r, width - r, r, Angle.ToRadians(0), Angle.ToRadians(90)),
+            new Line(length - r, width, r, width),
+            new Arc(r, width - r, r, Angle.ToRadians(90), Angle.ToRadians(180)),
+            new Line(0, width - r, 0, r),
+            new Arc(r, r, r, Angle.ToRadians(180), Angle.ToRadians(270)),
+        };
+    }
+
+    private static List<Entity> MakeCircle(double cx, double cy, double radius)
+    {
+        return new List<Entity> { new Circle(cx, cy, radius) };
+    }
+
+    private static List<Entity> Translate(List<Entity> entities, double dx, double dy)
+    {
+        var result = new List<Entity>();
+        foreach (var e in entities)
+        {
+            if (e is Line line)
+                result.Add(new Line(line.pt1.X + dx, line.pt1.Y + dy, line.pt2.X + dx, line.pt2.Y + dy));
+            else if (e is Arc arc)
+                result.Add(new Arc(arc.Center.X + dx, arc.Center.Y + dy, arc.Radius, arc.StartAngle, arc.EndAngle));
+            else if (e is Circle circle)
+                result.Add(new Circle(circle.Center.X + dx, circle.Center.Y + dy, circle.Radius));
+        }
+        return result;
+    }
+
+    #endregion
+
+    #region Circle vs Circle
+
+    [Fact]
+    public void CircleToCircle_Right_ReturnsGap()
+    {
+        var a = MakeCircle(0, 0, 5);
+        var b = MakeCircle(20, 0, 5);
+
+        var dist = SpatialQuery.DirectionalDistance(a, b, new Vector(1, 0));
+
+        Assert.InRange(dist, 9.9, 10.1);
+    }
+
+    [Fact]
+    public void CircleToCircle_Left_ReturnsGap()
+    {
+        var a = MakeCircle(20, 0, 5);
+        var b = MakeCircle(0, 0, 5);
+
+        var dist = SpatialQuery.DirectionalDistance(a, b, new Vector(-1, 0));
+
+        Assert.InRange(dist, 9.9, 10.1);
+    }
+
+    [Fact]
+    public void CircleToCircle_Up_ReturnsGap()
+    {
+        var a = MakeCircle(0, 0, 5);
+        var b = MakeCircle(0, 20, 5);
+
+        var dist = SpatialQuery.DirectionalDistance(a, b, new Vector(0, 1));
+
+        Assert.InRange(dist, 9.9, 10.1);
+    }
+
+    [Fact]
+    public void CircleToCircle_Touching_ReturnsZero()
+    {
+        var a = MakeCircle(0, 0, 5);
+        var b = MakeCircle(10, 0, 5);
+
+        var dist = SpatialQuery.DirectionalDistance(a, b, new Vector(1, 0));
+
+        Assert.InRange(dist, -0.01, 0.01);
+    }
+
+    [Fact]
+    public void CircleToCircle_NoPath_ReturnsMaxValue()
+    {
+        var a = MakeCircle(0, 0, 3);
+        var b = MakeCircle(0, 20, 3);
+
+        var dist = SpatialQuery.DirectionalDistance(a, b, new Vector(1, 0));
+
+        Assert.Equal(double.MaxValue, dist);
+    }
+
+    [Fact]
+    public void CircleToCircle_PushDirection_Right()
+    {
+        var a = MakeCircle(0, 0, 5);
+        var b = MakeCircle(20, 0, 5);
+
+        var dist = SpatialQuery.DirectionalDistance(a, b, PushDirection.Right);
+
+        Assert.InRange(dist, 9.9, 10.1);
+    }
+
+    #endregion
+
+    #region Square vs Square
+
+    [Fact]
+    public void SquareToSquare_Right_ReturnsGap()
+    {
+        var a = MakeSquare(10);
+        var b = Translate(MakeSquare(10), 25, 0);
+
+        var dist = SpatialQuery.DirectionalDistance(a, b, new Vector(1, 0));
+
+        Assert.InRange(dist, 14.9, 15.1);
+    }
+
+    [Fact]
+    public void SquareToSquare_Left_ReturnsGap()
+    {
+        var a = Translate(MakeSquare(10), 25, 0);
+        var b = MakeSquare(10);
+
+        var dist = SpatialQuery.DirectionalDistance(a, b, new Vector(-1, 0));
+
+        Assert.InRange(dist, 14.9, 15.1);
+    }
+
+    [Fact]
+    public void SquareToSquare_Down_ReturnsGap()
+    {
+        var a = Translate(MakeSquare(10), 0, 25);
+        var b = MakeSquare(10);
+
+        var dist = SpatialQuery.DirectionalDistance(a, b, new Vector(0, -1));
+
+        Assert.InRange(dist, 14.9, 15.1);
+    }
+
+    [Fact]
+    public void SquareToSquare_Touching_ReturnsZero()
+    {
+        var a = MakeSquare(10);
+        var b = Translate(MakeSquare(10), 10, 0);
+
+        var dist = SpatialQuery.DirectionalDistance(a, b, new Vector(1, 0));
+
+        Assert.InRange(dist, -0.01, 0.01);
+    }
+
+    [Fact]
+    public void SquareToSquare_NoOverlap_ReturnsMaxValue()
+    {
+        var a = MakeSquare(10);
+        var b = Translate(MakeSquare(10), 0, 20);
+
+        var dist = SpatialQuery.DirectionalDistance(a, b, new Vector(1, 0));
+
+        Assert.Equal(double.MaxValue, dist);
+    }
+
+    [Fact]
+    public void SquareToSquare_PartialOverlap_Right()
+    {
+        var a = MakeSquare(10);
+        var b = Translate(MakeSquare(10), 20, 5);
+
+        var dist = SpatialQuery.DirectionalDistance(a, b, new Vector(1, 0));
+
+        Assert.InRange(dist, 9.9, 10.1);
+    }
+
+    #endregion
+
+    #region Rounded Rectangle
+
+    [Fact]
+    public void RoundedRect_Right_ReturnsGap()
+    {
+        var a = MakeRoundedRect(20, 10, 2);
+        var b = Translate(MakeRoundedRect(20, 10, 2), 30, 0);
+
+        var dist = SpatialQuery.DirectionalDistance(a, b, new Vector(1, 0));
+
+        Assert.InRange(dist, 9.9, 10.1);
+    }
+
+    [Fact]
+    public void RoundedRect_Up_ReturnsGap()
+    {
+        var a = MakeRoundedRect(20, 10, 2);
+        var b = Translate(MakeRoundedRect(20, 10, 2), 0, 25);
+
+        var dist = SpatialQuery.DirectionalDistance(a, b, new Vector(0, 1));
+
+        Assert.InRange(dist, 14.9, 15.1);
+    }
+
+    [Fact]
+    public void RoundedRect_Touching_ReturnsZero()
+    {
+        var a = MakeRoundedRect(20, 10, 2);
+        var b = Translate(MakeRoundedRect(20, 10, 2), 20, 0);
+
+        var dist = SpatialQuery.DirectionalDistance(a, b, new Vector(1, 0));
+
+        Assert.InRange(dist, -0.01, 0.01);
+    }
+
+    [Fact]
+    public void RoundedRect_Diagonal_ReturnsDistance()
+    {
+        var dir = new Vector(1 / System.Math.Sqrt(2), 1 / System.Math.Sqrt(2));
+        var a = MakeRoundedRect(10, 10, 2);
+        var b = Translate(MakeRoundedRect(10, 10, 2), 20, 20);
+
+        var dist = SpatialQuery.DirectionalDistance(a, b, dir);
+
+        Assert.True(dist > 0 && dist < double.MaxValue);
+    }
+
+    #endregion
+
+    #region Circle vs Square
+
+    [Fact]
+    public void CircleToSquare_Right_ReturnsGap()
+    {
+        var circle = MakeCircle(0, 5, 5);
+        var square = Translate(MakeSquare(10), 15, 0);
+
+        var dist = SpatialQuery.DirectionalDistance(circle, square, new Vector(1, 0));
+
+        Assert.InRange(dist, 9.9, 10.1);
+    }
+
+    [Fact]
+    public void SquareToCircle_Right_ReturnsGap()
+    {
+        var square = MakeSquare(10);
+        var circle = MakeCircle(25, 5, 5);
+
+        var dist = SpatialQuery.DirectionalDistance(square, circle, new Vector(1, 0));
+
+        Assert.InRange(dist, 9.9, 10.1);
+    }
+
+    [Fact]
+    public void CircleToSquare_Touching_ReturnsZero()
+    {
+        var circle = MakeCircle(0, 5, 5);
+        var square = Translate(MakeSquare(10), 5, 0);
+
+        var dist = SpatialQuery.DirectionalDistance(circle, square, new Vector(1, 0));
+
+        Assert.InRange(dist, -0.01, 0.01);
+    }
+
+    #endregion
+
+    #region Circle vs Rounded Rectangle
+
+    [Fact]
+    public void CircleToRoundedRect_Right_ReturnsGap()
+    {
+        var circle = MakeCircle(0, 5, 5);
+        var rect = Translate(MakeRoundedRect(20, 10, 2), 15, 0);
+
+        var dist = SpatialQuery.DirectionalDistance(circle, rect, new Vector(1, 0));
+
+        Assert.InRange(dist, 9.9, 10.1);
+    }
+
+    [Fact]
+    public void RoundedRectToCircle_Left_ReturnsGap()
+    {
+        var rect = Translate(MakeRoundedRect(20, 10, 2), 15, 0);
+        var circle = MakeCircle(0, 5, 5);
+
+        var dist = SpatialQuery.DirectionalDistance(rect, circle, new Vector(-1, 0));
+
+        Assert.InRange(dist, 9.9, 10.1);
+    }
+
+    #endregion
+
+    #region Edge cases
+
+    [Fact]
+    public void EmptyLists_ReturnsMaxValue()
+    {
+        var a = new List<Entity>();
+        var b = new List<Entity>();
+
+        var dist = SpatialQuery.DirectionalDistance(a, b, new Vector(1, 0));
+
+        Assert.Equal(double.MaxValue, dist);
+    }
+
+    [Fact]
+    public void Symmetry_LeftRightReturnSameDistance()
+    {
+        var a = MakeSquare(10);
+        var b = Translate(MakeSquare(10), 25, 0);
+
+        var right = SpatialQuery.DirectionalDistance(a, b, new Vector(1, 0));
+        var left = SpatialQuery.DirectionalDistance(b, a, new Vector(-1, 0));
+
+        Assert.InRange(System.Math.Abs(right - left), 0, 0.01);
+    }
+
+    [Fact]
+    public void Symmetry_CirclesLeftRightSame()
+    {
+        var a = MakeCircle(0, 0, 5);
+        var b = MakeCircle(20, 0, 5);
+
+        var right = SpatialQuery.DirectionalDistance(a, b, new Vector(1, 0));
+        var left = SpatialQuery.DirectionalDistance(b, a, new Vector(-1, 0));
+
+        Assert.InRange(System.Math.Abs(right - left), 0, 0.01);
+    }
+
+    #endregion
+}

OpenNest.Tests/IO/DxfRoundtripTests.cs

@@ -11,17 +11,14 @@ public class DxfRoundtripTests
     private static List<Entity> ExportAndReimport(List<Entity> geometry)
     {
         var program = ConvertGeometry.ToProgram(geometry);
-        var exporter = new DxfExporter();
-        var importer = new DxfImporter();
-
         using var exportStream = new MemoryStream();
-        exporter.ExportProgram(program, exportStream);
+        Dxf.ExportProgram(program, exportStream);
         var bytes = exportStream.ToArray();
 
         var importStream = new MemoryStream(bytes);
-        var success = importer.GetGeometry(importStream, out var reimported);
+        var reimported = Dxf.GetGeometry(importStream);
 
-        Assert.True(success, "Failed to re-import exported DXF");
+        Assert.NotEmpty(reimported);
         return reimported;
     }
 

OpenNest.Tests/Splitting/DrawingSplitterTests.cs

@@ -369,8 +369,7 @@ public class DrawingSplitterTests
             var writer = new OpenNest.IO.SplitDxfWriter();
             writer.Write(tempPath, results[0]);
 
-            var reimporter = new OpenNest.IO.DxfImporter();
-            var reimportResult = reimporter.Import(tempPath);
+            var reimportResult = OpenNest.IO.Dxf.Import(tempPath);
 
             var afterArcs = reimportResult.Entities.OfType<Arc>().Count();
             var afterCircles = reimportResult.Entities.OfType<Circle>().Count();

OpenNest.Tests/Splitting/SplitDxfWriterEtchLayerTests.cs

@@ -185,8 +185,7 @@ public class SplitDxfWriterEtchLayerTests
                 writer.Write(tempPath, splitDrawing);
 
                 // Re-import via DxfImporter (same path as CadConverterForm)
-                var importer = new DxfImporter();
-                var result = importer.Import(tempPath);
+                var result = Dxf.Import(tempPath);
 
                 // ETCH entities should be filtered during import (like BEND)
                 var etchEntities = result.Entities

OpenNest.Tests/Strategies/StrategyOverlapTests.cs

@@ -23,8 +23,7 @@ public class StrategyOverlapTests
         if (!System.IO.File.Exists(DxfPath))
             return null;
 
-        var importer = new DxfImporter();
-        importer.GetGeometry(DxfPath, out var geometry);
+        var geometry = Dxf.GetGeometry(DxfPath);
         var pgm = ConvertGeometry.ToProgram(geometry);
         return new Drawing("PT15", pgm);
     }

OpenNest.Training/Program.cs

@@ -104,7 +104,6 @@ int RunDataCollection(string dir, string dbPath, string saveDir, double s, strin
     if (backfilled > 0)
         Console.WriteLine($"Backfilled PerimeterToAreaRatio for {backfilled} existing parts");
 
-    var importer = new DxfImporter();
     var colorIndex = 0;
     var processed = 0;
     var skippedGeometry = 0;
@@ -129,7 +128,8 @@ int RunDataCollection(string dir, string dbPath, string saveDir, double s, strin
                 continue;
             }
 
-            if (!importer.GetGeometry(file, out var entities))
+            var entities = Dxf.GetGeometry(file);
+            if (entities.Count == 0)
             {
                 Console.WriteLine(" - SKIP (no geometry)");
                 skippedGeometry++;

OpenNest/ArchUnits.cs

@@ -0,0 +1,84 @@
+using OpenNest.IO.Bom;
+using System;
+using System.Drawing;
+using System.Text;
+using System.Text.RegularExpressions;
+using System.Windows.Forms;
+
+namespace OpenNest
+{
+    public static class ArchUnits
+    {
+        private static readonly Regex UnitRegex =
+            new Regex("^(?<Feet>\\d+\\.?\\d*\\s*')?\\s*(?<Inches>\\d+\\.?\\d*\\s*\")?$");
+
+        public static double ParseToInches(string input)
+        {
+            if (string.IsNullOrWhiteSpace(input))
+                return 0;
+
+            var sb = new StringBuilder(input.Trim().ToLower());
+
+            sb.Replace("ft", "'");
+            sb.Replace("feet", "'");
+            sb.Replace("foot", "'");
+            sb.Replace("inches", "\"");
+            sb.Replace("inch", "\"");
+            sb.Replace("in", "\"");
+
+            input = Fraction.ReplaceFractionsWithDecimals(sb.ToString());
+
+            var match = UnitRegex.Match(input);
+
+            if (!match.Success)
+            {
+                if (!input.Contains("'") && !input.Contains("\""))
+                {
+                    if (double.TryParse(input.Trim(), out var plainInches))
+                        return System.Math.Round(plainInches, 8);
+                }
+
+                throw new FormatException("Input is not in a valid format.");
+            }
+
+            var feet = match.Groups["Feet"];
+            var inches = match.Groups["Inches"];
+            var totalInches = 0.0;
+
+            if (feet.Success)
+            {
+                var x = double.Parse(feet.Value.Remove(feet.Length - 1));
+                totalInches += x * 12;
+            }
+
+            if (inches.Success)
+            {
+                var x = double.Parse(inches.Value.Remove(inches.Length - 1));
+                totalInches += x;
+            }
+
+            return System.Math.Round(totalInches, 8);
+        }
+
+        public static double GetLengthInches(TextBox tb)
+        {
+            try
+            {
+                if (double.TryParse(tb.Text, out var d))
+                {
+                    tb.ForeColor = SystemColors.WindowText;
+                    return d;
+                }
+
+                var x = ParseToInches(tb.Text);
+                tb.ForeColor = SystemColors.WindowText;
+                return x;
+            }
+            catch
+            {
+                tb.ForeColor = Color.Red;
+                return double.NaN;
+            }
+        }
+    }
+}

OpenNest/Controls/ActionManager.cs

@@ -0,0 +1,118 @@
+using System;
+using System.ComponentModel;
+using Action = OpenNest.Actions.Action;
+
+namespace OpenNest.Controls
+{
+    internal class ActionManager
+    {
+        private readonly PlateView view;
+        private Action currentAction;
+        private Action previousAction;
+
+        public ActionManager(PlateView view)
+        {
+            this.view = view;
+        }
+
+        public Action CurrentAction => currentAction;
+
+        public void SetAction(Type type)
+        {
+            var action = Activator.CreateInstance(type, view) as Action;
+            if (action == null)
+                return;
+
+            if (currentAction != null)
+            {
+                if (type == typeof(Actions.ActionSelect) && !(currentAction is Actions.ActionSelect))
+                    previousAction = currentAction;
+                else
+                    previousAction = null;
+
+                currentAction.CancelAction();
+                currentAction.DisconnectEvents();
+                currentAction = null;
+            }
+
+            currentAction = action;
+            view.Status = GetDisplayName(type);
+        }
+
+        public void SetAction(Type type, params object[] args)
+        {
+            if (currentAction != null)
+            {
+                previousAction = null;
+                currentAction.CancelAction();
+                currentAction.DisconnectEvents();
+                currentAction = null;
+            }
+
+            Array.Resize(ref args, args.Length + 1);
+            for (var i = args.Length - 2; i >= 0; i--)
+                args[i + 1] = args[i];
+            args[0] = view;
+
+            var action = Activator.CreateInstance(type, args) as Action;
+            if (action == null)
+                return;
+
+            currentAction = action;
+            view.Status = GetDisplayName(type);
+        }
+
+        public void ProcessEscapeKey()
+        {
+            if (currentAction.IsBusy())
+                currentAction.CancelAction();
+            else if (currentAction is Actions.ActionSelect && previousAction != null)
+                RestorePreviousAction();
+            else
+                view.SetAction(typeof(Actions.ActionSelect));
+        }
+
+        public void RestorePreviousAction()
+        {
+            var action = previousAction;
+            previousAction = null;
+
+            currentAction.CancelAction();
+            currentAction.DisconnectEvents();
+
+            action.ConnectEvents();
+            currentAction = action;
+
+            view.Status = GetDisplayName(action.GetType());
+        }
+
+        public void OnPlateChanged()
+        {
+            if (currentAction == null || !currentAction.SurvivesPlateChange)
+                view.SetAction(typeof(Actions.ActionSelect));
+            else
+                currentAction.OnPlateChanged();
+        }
+
+        public void Cleanup()
+        {
+            if (currentAction != null)
+            {
+                currentAction.CancelAction();
+                currentAction.DisconnectEvents();
+                currentAction = null;
+            }
+        }
+
+        private string GetDisplayName(Type type)
+        {
+            var attributes = type.GetCustomAttributes(true);
+            foreach (var attr in attributes)
+            {
+                if (attr is DisplayNameAttribute displayNameAttr)
+                    return displayNameAttr.DisplayName;
+            }
+            return type.Name;
+        }
+    }
+}

OpenNest/Controls/CutOffHandler.cs

@@ -0,0 +1,81 @@
+using OpenNest.CNC;
+using OpenNest.Geometry;
+using System.Collections.Generic;
+
+namespace OpenNest.Controls
+{
+    internal class CutOffHandler
+    {
+        private readonly PlateView view;
+        private Dictionary<Part, Geometry.Entity> dragPerimeterCache;
+
+        public CutOffHandler(PlateView view)
+        {
+            this.view = view;
+        }
+
+        public bool IsDragging { get; private set; }
+
+        public CutOff TryStartDrag(Vector point, double tolerance)
+        {
+            var hitCutOff = GetCutOffAtPoint(point, tolerance);
+            if (hitCutOff == null)
+                return null;
+
+            IsDragging = true;
+            dragPerimeterCache = Plate.BuildPerimeterCache(view.Plate);
+            return hitCutOff;
+        }
+
+        public void UpdateDrag(Vector currentPoint, CutOff cutOff)
+        {
+            if (!IsDragging || cutOff == null)
+                return;
+
+            if (cutOff.Axis == CutOffAxis.Vertical)
+                cutOff.Position = new Vector(currentPoint.X, cutOff.Position.Y);
+            else
+                cutOff.Position = new Vector(cutOff.Position.X, currentPoint.Y);
+
+            cutOff.Regenerate(view.Plate, view.CutOffSettings, dragPerimeterCache);
+            view.Invalidate();
+        }
+
+        public void EndDrag()
+        {
+            if (!IsDragging)
+                return;
+
+            IsDragging = false;
+            dragPerimeterCache = null;
+            view.Plate.RegenerateCutOffs(view.CutOffSettings);
+            view.Invalidate();
+        }
+
+        public CutOff GetCutOffAtPoint(Vector point, double tolerance)
+        {
+            if (view.Plate?.CutOffs == null)
+                return null;
+
+            foreach (var cutoff in view.Plate.CutOffs)
+            {
+                var program = cutoff.Drawing?.Program;
+                if (program == null)
+                    continue;
+
+                for (var i = 0; i < program.Codes.Count - 1; i += 2)
+                {
+                    if (program.Codes[i] is RapidMove rapid &&
+                        program.Codes[i + 1] is LinearMove linear)
+                    {
+                        var line = new Line(rapid.EndPoint, linear.EndPoint);
+                        if (line.ClosestPointTo(point).DistanceTo(point) <= tolerance)
+                            return cutoff;
+                    }
+                }
+            }
+
+            return null;
+        }
+    }
+}

OpenNest/Controls/CuttingPanel.cs

@@ -11,7 +11,7 @@ namespace OpenNest.Controls
             { "None", "Line", "Arc", "Line + Arc", "Clean Hole", "Line + Line" };
 
         private static readonly string[] LeadOutTypes =
-            { "None", "Line", "Arc", "Microtab" };
+            { "None", "Line", "Arc" };
 
         private readonly TabControl tabControl;
         private readonly ComboBox cboExternalLeadIn, cboExternalLeadOut;
@@ -424,9 +424,6 @@ namespace OpenNest.Controls
                 case 2:
                     AddNumericField(panel, "Radius:", 0.25, ref y, "Radius");
                     break;
-                case 3:
-                    AddNumericField(panel, "Gap Size:", 0.06, ref y, "GapSize");
-                    break;
             }
         }
 
@@ -513,10 +510,6 @@ namespace OpenNest.Controls
                     combo.SelectedIndex = 2;
                     SetParam(panel, "Radius", arc.Radius);
                     break;
-                case MicrotabLeadOut microtab:
-                    combo.SelectedIndex = 3;
-                    SetParam(panel, "GapSize", microtab.GapSize);
-                    break;
                 default:
                     combo.SelectedIndex = 0;
                     break;
@@ -572,10 +565,6 @@ namespace OpenNest.Controls
                 {
                     Radius = GetParam(panel, "Radius", 0.25)
                 },
-                3 => new MicrotabLeadOut
-                {
-                    GapSize = GetParam(panel, "GapSize", 0.06)
-                },
                 _ => new NoLeadOut()
             };
         }

OpenNest/Controls/DrawControl.cs

@@ -29,7 +29,7 @@ namespace OpenNest.Controls
         {
             ViewScale = 1.0f;
             ViewScaleMin = 0.3f;
-            ViewScaleMax = 3000;
+            ViewScaleMax = 10000;
             origin = new PointF(100, 100);
         }
 

OpenNest/Controls/DrawingListBox.cs

@@ -8,16 +8,14 @@ namespace OpenNest.Controls
 
     public class DrawingListBox : ListBox
     {
+        private const int WM_ERASEBKGND = 0x0014;
+
         private readonly Size imageSize;
         private readonly Font nameFont;
         private Point lastClickLocation;
 
         public DrawingListBox()
         {
-            SetStyle(
-                ControlStyles.AllPaintingInWmPaint |
-                ControlStyles.OptimizedDoubleBuffer, true);
-
             DrawMode = DrawMode.OwnerDrawFixed;
             ItemHeight = 85;
 
@@ -125,6 +123,10 @@ namespace OpenNest.Controls
                 pt.Y += 18;
                 e.Graphics.DrawString(text3, Font, detailBrush, pt);
             }
+
+            using var separatorPen = new Pen(Color.LightGray);
+            var separatorY = e.Bounds.Bottom - 1;
+            e.Graphics.DrawLine(separatorPen, e.Bounds.X, separatorY, e.Bounds.Right, separatorY);
         }
 
         protected override void OnMouseMove(MouseEventArgs e)
@@ -145,6 +147,30 @@ namespace OpenNest.Controls
             base.OnMouseDown(e);
             lastClickLocation = e.Location;
         }
+
+        protected override void WndProc(ref Message m)
+        {
+            if (m.Msg == WM_ERASEBKGND)
+            {
+                var itemBottom = 0;
+
+                if (Items.Count > 0)
+                {
+                    var lastVisible = System.Math.Min(TopIndex + (ClientSize.Height / ItemHeight), Items.Count - 1);
+                    itemBottom = GetItemRectangle(lastVisible).Bottom;
+                }
+
+                if (itemBottom < ClientSize.Height)
+                {
+                    using var g = Graphics.FromHdc(m.WParam);
+                    g.FillRectangle(Brushes.White, 0, itemBottom, ClientSize.Width, ClientSize.Height - itemBottom);
+                }
+
+                m.Result = (IntPtr)1;
+                return;
+            }
+            base.WndProc(ref m);
+        }
     }
 
     public static class PointExtensions

OpenNest/Controls/FileListControl.cs

@@ -19,6 +19,7 @@ namespace OpenNest.Controls
         public List<Entity> Entities { get; set; } = new();
         public List<Entity> OriginalEntities { get; set; }
         public List<Bend> Bends { get; set; } = new();
+        public HashSet<Guid> SuppressedEntityIds { get; set; }
         public Box Bounds { get; set; }
         public int EntityCount { get; set; }
     }

OpenNest/Controls/FilterPanel.cs

@@ -154,7 +154,10 @@ namespace OpenNest.Controls
                 Font = new Font("Segoe UI", 9f)
             };
             list.ItemCheck += (s, e) =>
-                BeginInvoke((Action)(() => FilterChanged?.Invoke(this, EventArgs.Empty)));
+            {
+                if (IsHandleCreated)
+                    BeginInvoke((Action)(() => FilterChanged?.Invoke(this, EventArgs.Empty)));
+            };
             return list;
         }
 
@@ -167,10 +170,11 @@ namespace OpenNest.Controls
             layersList.Items.Clear();
             var layers = entities
                 .Where(e => e.Layer != null)
-                .Select(e => e.Layer.Name)
-                .Distinct();
+                .Select(e => e.Layer)
+                .GroupBy(l => l.Name)
+                .Select(g => g.First());
             foreach (var layer in layers)
-                layersList.Items.Add(layer, true); // checked = visible
+                layersList.Items.Add(layer.Name, layer.IsVisible);
 
             layersPanel.HeaderText = $"Layers ({layersList.Items.Count})";
 
@@ -188,10 +192,10 @@ namespace OpenNest.Controls
             // Line Types
             lineTypesList.Items.Clear();
             var lineTypes = entities
-                .Select(e => e.LineTypeName ?? "Continuous")
-                .Distinct();
+                .GroupBy(e => e.LineTypeName ?? "Continuous")
+                .Select(g => new { Name = g.Key, Visible = g.Any(e => e.IsVisible) });
             foreach (var lt in lineTypes)
-                lineTypesList.Items.Add(lt, true); // checked = visible
+                lineTypesList.Items.Add(lt.Name, lt.Visible);
 
             lineTypesPanel.HeaderText = $"Line Types ({lineTypesList.Items.Count})";
 

OpenNest/Controls/PlateRenderer.cs

@@ -168,7 +168,7 @@ namespace OpenNest.Controls
                 if (program == null || program.Codes.Count == 0)
                     continue;
 
-                var activePen = cutoff == view.SelectedCutOff ? selectedPen : pen;
+                var activePen = view.Selection.SelectedCutOffs.Contains(cutoff) ? selectedPen : pen;
 
                 for (var i = 0; i < program.Codes.Count - 1; i += 2)
                 {

OpenNest/Controls/PlateView.cs

@@ -1,5 +1,4 @@
 using OpenNest.Actions;
-using OpenNest.CNC;
 using OpenNest.Collections;
 using OpenNest.Engine.Fill;
 using OpenNest.Forms;
@@ -8,7 +7,6 @@ using OpenNest.Math;
 using System;
 using System.Collections.Generic;
 using System.Collections.ObjectModel;
-using System.ComponentModel;
 using System.Diagnostics;
 using System.Drawing;
 using System.Drawing.Drawing2D;
@@ -16,31 +14,30 @@ using System.Linq;
 using System.Threading;
 using System.Threading.Tasks;
 using System.Windows.Forms;
-using Action = OpenNest.Actions.Action;
 using Timer = System.Timers.Timer;
 
 namespace OpenNest.Controls
 {
     public class PlateView : DrawControl
     {
-        private readonly Font programIdFont;
         private readonly Timer redrawTimer;
 
         private string status;
         private Plate plate;
-        private Action currentAction;
-        private Action previousAction;
+        private ActionManager actionManager;
         private CutOffSettings cutOffSettings = new CutOffSettings();
-        private CutOff selectedCutOff;
-        private bool draggingCutOff;
-        private Dictionary<Part, Geometry.Entity> dragPerimeterCache;
+        private SelectionManager selection;
+        private CutOffHandler cutOffHandler;
+        private PreviewManager previewManager;
         protected List<LayoutPart> parts;
-        private List<LayoutPart> stationaryParts = new List<LayoutPart>();
-        private List<LayoutPart> activeParts = new List<LayoutPart>();
         private Point middleMouseDownPoint;
         private Box activeWorkArea;
         private List<Box> debugRemnants;
         private PlateRenderer renderer;
+        private LayoutPart hoveredPart;
+        private Point hoverPoint;
+        private bool showTooltip;
+        private Timer hoverTimer;
 
         public Box ActiveWorkArea
         {
@@ -64,13 +61,23 @@ namespace OpenNest.Controls
 
         public List<int> DebugRemnantPriorities { get; set; }
 
-        public List<LayoutPart> SelectedParts;
-        public ReadOnlyCollection<LayoutPart> Parts;
+        public List<LayoutPart> SelectedParts => selection.SelectedParts;
+        public ReadOnlyCollection<LayoutPart> Parts => new ReadOnlyCollection<LayoutPart>(parts);
+
+        internal SelectionManager Selection => selection;
+        internal CutOffHandler CutOffs => cutOffHandler;
+        internal ActionManager Actions => actionManager;
+        internal PreviewManager Previews => previewManager;
 
         public event EventHandler<ItemAddedEventArgs<Part>> PartAdded;
         public event EventHandler<ItemRemovedEventArgs<Part>> PartRemoved;
         public event EventHandler StatusChanged;
-        public event EventHandler SelectionChanged;
+
+        public event EventHandler SelectionChanged
+        {
+            add => selection.SelectionChanged += value;
+            remove => selection.SelectionChanged -= value;
+        }
 
         public PlateView()
             : this(ColorScheme.Default)
@@ -80,11 +87,11 @@ namespace OpenNest.Controls
         public PlateView(ColorScheme colorScheme)
         {
             Plate = new Plate(60, 120);
-            programIdFont = new Font(DefaultFont, FontStyle.Bold | FontStyle.Underline);
             origin = new PointF();
             parts = new List<LayoutPart>();
-            Parts = new ReadOnlyCollection<LayoutPart>(parts);
-            SelectedParts = new List<LayoutPart>();
+            selection = new SelectionManager(this);
+            cutOffHandler = new CutOffHandler(this);
+            previewManager = new PreviewManager(this);
 
             redrawTimer = new Timer()
             {
@@ -94,6 +101,9 @@ namespace OpenNest.Controls
             };
             redrawTimer.Elapsed += redrawTimer_Elapsed;
 
+            hoverTimer = new Timer() { AutoReset = false, Interval = 1000 };
+            hoverTimer.Elapsed += hoverTimer_Elapsed;
+
             SetStyle(
                 ControlStyles.AllPaintingInWmPaint |
                 ControlStyles.OptimizedDoubleBuffer |
@@ -115,7 +125,8 @@ namespace OpenNest.Controls
             DrawOffset = false;
             FillParts = true;
             renderer = new PlateRenderer(this);
-            SetAction(typeof(ActionSelect));
+            actionManager = new ActionManager(this);
+            actionManager.SetAction(typeof(ActionSelect));
 
             UpdateMatrix();
         }
@@ -148,14 +159,9 @@ namespace OpenNest.Controls
 
         internal List<LayoutPart> LayoutParts => parts;
 
-        internal IReadOnlyList<LayoutPart> PreviewParts =>
-            activeParts.Count > 0 ? activeParts : stationaryParts;
-
-        internal Brush PreviewBrush =>
-            activeParts.Count > 0 ? ColorScheme.ActivePreviewPartBrush : ColorScheme.PreviewPartBrush;
-
-        internal Pen PreviewPen =>
-            activeParts.Count > 0 ? ColorScheme.ActivePreviewPartPen : ColorScheme.PreviewPartPen;
+        internal IReadOnlyList<LayoutPart> PreviewParts => previewManager.PreviewParts;
+        internal Brush PreviewBrush => previewManager.PreviewBrush;
+        internal Pen PreviewPen => previewManager.PreviewPen;
 
         internal RectangleF GetViewBounds() =>
             new RectangleF(-origin.X, -origin.Y, Width, Height);
@@ -173,16 +179,6 @@ namespace OpenNest.Controls
             }
         }
 
-        public CutOff SelectedCutOff
-        {
-            get => selectedCutOff;
-            set
-            {
-                selectedCutOff = value;
-                Invalidate();
-            }
-        }
-
         public double RotateIncrementAngle { get; set; }
 
         public double OffsetIncrementDistance { get; set; }
@@ -200,9 +196,8 @@ namespace OpenNest.Controls
                 plate.PartAdded -= plate_PartAdded;
                 plate.PartRemoved -= plate_PartRemoved;
                 parts.Clear();
-                stationaryParts.Clear();
-                activeParts.Clear();
-                SelectedParts.Clear();
+                previewManager.Clear();
+                selection.Clear();
             }
 
             plate = p;
@@ -212,10 +207,7 @@ namespace OpenNest.Controls
             foreach (var part in plate.Parts)
                 parts.Add(LayoutPart.Create(part, this));
 
-            if (currentAction == null || !currentAction.SurvivesPlateChange)
-                SetAction(typeof(ActionSelect));
-            else
-                currentAction.OnPlateChanged();
+            actionManager?.OnPlateChanged();
         }
 
         public string Status
@@ -233,7 +225,6 @@ namespace OpenNest.Controls
         protected override void OnMouseEnter(EventArgs e)
         {
             base.OnMouseEnter(e);
-            if (!Focused) Focus();
         }
 
         protected override void OnDragEnter(DragEventArgs drgevent)
@@ -257,22 +248,25 @@ namespace OpenNest.Controls
 
         protected override void OnMouseDown(MouseEventArgs e)
         {
+            if (!Focused) Focus();
+
             if (e.Button == MouseButtons.Middle)
                 middleMouseDownPoint = e.Location;
 
-            if (e.Button == MouseButtons.Left && currentAction is ActionSelect)
+            if (e.Button == MouseButtons.Left && actionManager.CurrentAction is ActionSelect)
             {
-                var hitCutOff = GetCutOffAtPoint(CurrentPoint, 5.0 / ViewScale);
+                var hitCutOff = cutOffHandler.TryStartDrag(CurrentPoint, 5.0 / ViewScale);
                 if (hitCutOff != null)
                 {
-                    SelectedCutOff = hitCutOff;
-                    draggingCutOff = true;
-                    dragPerimeterCache = Plate.BuildPerimeterCache(Plate);
+                    selection.DeselectParts();
+                    selection.SelectedCutOffs.Clear();
+                    selection.SelectedCutOffs.Add(hitCutOff);
+                    Invalidate();
                     return;
                 }
                 else
                 {
-                    SelectedCutOff = null;
+                    selection.DeselectCutOffs();
                 }
             }
 
@@ -288,17 +282,14 @@ namespace OpenNest.Controls
 
                 if (dx * dx + dy * dy < 25)
                 {
-                    RotateSelectedParts(Angle.ToRadians(90));
+                    selection.RotateSelectedParts(Angle.ToRadians(90));
                     Invalidate();
                 }
             }
 
-            if (draggingCutOff && selectedCutOff != null)
+            if (cutOffHandler.IsDragging && selection.SelectedCutOffs.Count > 0)
             {
-                draggingCutOff = false;
-                dragPerimeterCache = null;
-                Plate.RegenerateCutOffs(cutOffSettings);
-                Invalidate();
+                cutOffHandler.EndDrag();
                 return;
             }
 
@@ -319,7 +310,7 @@ namespace OpenNest.Controls
 
                 var angle = Angle.ToRadians((e.Delta > 0 ? -increment : increment) * multiplier);
 
-                RotateSelectedParts(angle);
+                selection.RotateSelectedParts(angle);
             }
             else
             {
@@ -358,18 +349,30 @@ namespace OpenNest.Controls
 
             lastPoint = e.Location;
 
-            if (draggingCutOff && selectedCutOff != null)
+            if (cutOffHandler.IsDragging && selection.SelectedCutOffs.Count > 0)
             {
-                if (selectedCutOff.Axis == CutOffAxis.Vertical)
-                    selectedCutOff.Position = new Vector(CurrentPoint.X, selectedCutOff.Position.Y);
-                else
-                    selectedCutOff.Position = new Vector(selectedCutOff.Position.X, CurrentPoint.Y);
-
-                selectedCutOff.Regenerate(Plate, cutOffSettings, dragPerimeterCache);
-                Invalidate();
+                cutOffHandler.UpdateDrag(CurrentPoint, selection.SelectedCutOffs[0]);
                 return;
             }
 
+            if (e.Button == MouseButtons.None && actionManager.CurrentAction is ActionSelect)
+            {
+                hoverPoint = e.Location;
+                showTooltip = false;
+                hoverTimer.Stop();
+                hoverTimer.Start();
+
+                if (hoveredPart != null)
+                    Invalidate();
+            }
+            else if (hoveredPart != null || showTooltip)
+            {
+                hoveredPart = null;
+                hoverTimer.Stop();
+                showTooltip = false;
+                Invalidate();
+            }
+
             base.OnMouseMove(e);
         }
 
@@ -386,17 +389,7 @@ namespace OpenNest.Controls
             switch (e.KeyCode)
             {
                 case Keys.Delete:
-                    if (selectedCutOff != null)
-                    {
-                        Plate.CutOffs.Remove(selectedCutOff);
-                        selectedCutOff = null;
-                        Plate.RegenerateCutOffs(cutOffSettings);
-                        Invalidate();
-                    }
-                    else
-                    {
-                        RemoveSelectedParts();
-                    }
+                    selection.DeleteSelected();
                     break;
 
                 case Keys.F:
@@ -412,15 +405,7 @@ namespace OpenNest.Controls
             }
         }
 
-        public void ProcessEscapeKey()
-        {
-            if (currentAction.IsBusy())
-                currentAction.CancelAction();
-            else if (currentAction is ActionSelect && previousAction != null)
-                RestorePreviousAction();
-            else
-                SetAction(typeof(ActionSelect));
-        }
+        public void ProcessEscapeKey() => actionManager.ProcessEscapeKey();
 
         protected override bool ProcessDialogKey(Keys keyData)
         {
@@ -440,22 +425,22 @@ namespace OpenNest.Controls
 
                 case Keys.X:
                 case Keys.Shift | Keys.Left:
-                    PushSelected(PushDirection.Left);
+                    selection.PushSelected(PushDirection.Left);
                     break;
 
                 case Keys.Shift | Keys.X:
                 case Keys.Shift | Keys.Right:
-                    PushSelected(PushDirection.Right);
+                    selection.PushSelected(PushDirection.Right);
                     break;
 
                 case Keys.Shift | Keys.Y:
                 case Keys.Shift | Keys.Up:
-                    PushSelected(PushDirection.Up);
+                    selection.PushSelected(PushDirection.Up);
                     break;
 
                 case Keys.Y:
                 case Keys.Shift | Keys.Down:
-                    PushSelected(PushDirection.Down);
+                    selection.PushSelected(PushDirection.Down);
                     break;
 
                 case Keys.Right:
@@ -496,229 +481,53 @@ namespace OpenNest.Controls
             renderer.DrawDebugRemnants(e.Graphics);
 
             base.OnPaint(e);
+
+            if (hoveredPart != null && showTooltip)
+            {
+                e.Graphics.ResetTransform();
+                var text = hoveredPart.BasePart.BaseDrawing.Name;
+                var size = e.Graphics.MeasureString(text, Font);
+                var x = hoverPoint.X + 16f;
+                var y = hoverPoint.Y - size.Height - 6f;
+
+                if (x + size.Width + 8 > ClientSize.Width)
+                    x = hoverPoint.X - size.Width - 8;
+                if (y < 0)
+                    y = hoverPoint.Y + 20;
+
+                var rect = new RectangleF(x, y, size.Width + 6, size.Height + 4);
+                using (var bgBrush = new SolidBrush(Color.FromArgb(230, Color.White)))
+                    e.Graphics.FillRectangle(bgBrush, rect);
+                e.Graphics.DrawRectangle(Pens.DimGray, rect.X, rect.Y, rect.Width, rect.Height);
+                e.Graphics.DrawString(text, Font, Brushes.Black, x + 3, y + 2);
+            }
         }
 
         protected override void OnHandleDestroyed(EventArgs e)
         {
             base.OnHandleDestroyed(e);
-
-            if (currentAction != null)
-            {
-                currentAction.CancelAction();
-                currentAction.DisconnectEvents();
-                currentAction = null;
-            }
+            actionManager.Cleanup();
         }
 
         public override void Refresh()
         {
             parts.ForEach(p => p.Update(this));
-            stationaryParts.ForEach(p => p.Update(this));
-            activeParts.ForEach(p => p.Update(this));
+            previewManager.Update();
             Invalidate();
         }
 
-        public CutOff GetCutOffAtPoint(Vector point, double tolerance)
-        {
-            if (Plate?.CutOffs == null)
-                return null;
+        public CutOff GetCutOffAtPoint(Vector point, double tolerance) => cutOffHandler.GetCutOffAtPoint(point, tolerance);
 
-            foreach (var cutoff in Plate.CutOffs)
-            {
-                var program = cutoff.Drawing?.Program;
-                if (program == null)
-                    continue;
+        public LayoutPart GetPartAtControlPoint(Point pt) => selection.GetPartAtControlPoint(pt);
+        public LayoutPart GetPartAtGraphPoint(PointF pt) => selection.GetPartAtGraphPoint(pt);
+        public LayoutPart GetPartAtPoint(Vector pt) => selection.GetPartAtPoint(pt);
+        public IList<LayoutPart> GetPartsFromWindow(RectangleF rect, SelectionType selectionType) => selection.GetPartsFromWindow(rect, selectionType);
 
-                for (var i = 0; i < program.Codes.Count - 1; i += 2)
-                {
-                    if (program.Codes[i] is RapidMove rapid &&
-                        program.Codes[i + 1] is LinearMove linear)
-                    {
-                        var line = new Geometry.Line(rapid.EndPoint, linear.EndPoint);
-                        if (line.ClosestPointTo(point).DistanceTo(point) <= tolerance)
-                            return cutoff;
-                    }
-                }
-            }
+        public void SetAction(Type type) => actionManager.SetAction(type);
+        public void SetAction(Type type, params object[] args) => actionManager.SetAction(type, args);
 
-            return null;
-        }
-
-        public LayoutPart GetPartAtControlPoint(Point pt)
-        {
-            var pt2 = PointControlToGraph(pt);
-            return GetPartAtGraphPoint(pt2);
-        }
-
-        public LayoutPart GetPartAtGraphPoint(PointF pt)
-        {
-            for (int i = parts.Count - 1; i >= 0; --i)
-            {
-                if (parts[i].Path.IsVisible(pt))
-                    return parts[i];
-            }
-
-            return null;
-        }
-
-        public LayoutPart GetPartAtPoint(Vector pt)
-        {
-            var pt2 = PointWorldToGraph(pt);
-            return GetPartAtGraphPoint(pt2);
-        }
-
-        public IList<LayoutPart> GetPartsFromWindow(RectangleF rect, SelectionType selectionType)
-        {
-            var list = new List<LayoutPart>();
-
-            if (selectionType == SelectionType.Intersect)
-            {
-                for (int i = 0; i < parts.Count; ++i)
-                {
-                    var part = parts[i];
-                    var path = part.Path;
-                    var region = new Region(path);
-
-                    if (region.IsVisible(rect))
-                        list.Add(part);
-
-                    region.Dispose();
-                }
-            }
-            else
-            {
-                for (int i = 0; i < parts.Count; ++i)
-                {
-                    var part = parts[i];
-                    var path = part.Path;
-                    var bounds = path.GetBounds();
-
-                    if (rect.Contains(bounds))
-                        list.Add(part);
-                }
-            }
-
-            return list;
-        }
-
-        public void SetAction(Type type)
-        {
-            var action = Activator.CreateInstance(type, this) as Action;
-
-            if (action == null)
-                return;
-
-            if (currentAction != null)
-            {
-                if (type == typeof(ActionSelect) && !(currentAction is ActionSelect))
-                    previousAction = currentAction;
-                else
-                    previousAction = null;
-
-                currentAction.CancelAction();
-                currentAction.DisconnectEvents();
-                currentAction = null;
-            }
-
-            currentAction = action;
-
-            Status = GetDisplayName(type);
-        }
-
-        public void SetAction(Type type, params object[] args)
-        {
-            if (currentAction != null)
-            {
-                previousAction = null;
-                currentAction.CancelAction();
-                currentAction.DisconnectEvents();
-                currentAction = null;
-            }
-
-            Array.Resize(ref args, args.Length + 1);
-
-            // shift all elements to the right
-            for (int i = args.Length - 2; i >= 0; i--)
-                args[i + 1] = args[i];
-
-            // set the first argument to this.
-            args[0] = this;
-
-            var action = Activator.CreateInstance(type, args) as Action;
-
-            if (action == null)
-                return;
-
-            currentAction = action;
-
-            Status = GetDisplayName(type);
-        }
-
-        private void RestorePreviousAction()
-        {
-            var action = previousAction;
-            previousAction = null;
-
-            currentAction.CancelAction();
-            currentAction.DisconnectEvents();
-
-            action.ConnectEvents();
-            currentAction = action;
-
-            Status = GetDisplayName(action.GetType());
-        }
-
-        public void AlignSelected(AlignType alignType)
-        {
-            if (SelectedParts.Count == 0)
-                return;
-
-            AlignSelected(alignType, SelectedParts[0]);
-        }
-
-        public void AlignSelected(AlignType alignType, LayoutPart fixedPart)
-        {
-            switch (alignType)
-            {
-                case AlignType.Bottom:
-                    Align.Bottom(fixedPart.BasePart, SelectedParts.Select(p => p.BasePart).ToList());
-                    break;
-
-                case AlignType.Horizontally:
-                    Align.Horizontally(fixedPart.BasePart, SelectedParts.Select(p => p.BasePart).ToList());
-                    break;
-
-                case AlignType.Left:
-                    Align.Left(fixedPart.BasePart, SelectedParts.Select(p => p.BasePart).ToList());
-                    break;
-
-                case AlignType.Right:
-                    Align.Right(fixedPart.BasePart, SelectedParts.Select(p => p.BasePart).ToList());
-                    break;
-
-                case AlignType.Top:
-                    Align.Top(fixedPart.BasePart, SelectedParts.Select(p => p.BasePart).ToList());
-                    break;
-
-                case AlignType.Vertically:
-                    Align.Vertically(fixedPart.BasePart, SelectedParts.Select(p => p.BasePart).ToList());
-                    break;
-
-                case AlignType.EvenlySpaceHorizontally:
-                    Align.EvenlyDistributeHorizontally(SelectedParts.Select(p => p.BasePart).ToList());
-                    break;
-
-                case AlignType.EvenlySpaceVertically:
-                    Align.EvenlyDistributeVertically(SelectedParts.Select(p => p.BasePart).ToList());
-                    break;
-
-                default:
-                    return;
-            }
-
-            SelectedParts.ForEach(p => p.IsDirty = true);
-            Invalidate();
-        }
+        public void AlignSelected(AlignType alignType) => selection.AlignSelected(alignType);
+        public void AlignSelected(AlignType alignType, LayoutPart fixedPart) => selection.AlignSelected(alignType, fixedPart);
 
         public void AddPartFromDrawing(Drawing dwg, Vector location)
         {
@@ -731,51 +540,10 @@ namespace OpenNest.Controls
             Plate.Parts.Add(part);
         }
 
-        public void SetStationaryParts(List<Part> parts)
-        {
-            stationaryParts.Clear();
-            activeParts.Clear();
-
-            if (parts != null)
-            {
-                foreach (var part in parts)
-                    stationaryParts.Add(LayoutPart.Create(part, this));
-            }
-
-            Invalidate();
-        }
-
-        public void SetActiveParts(List<Part> parts)
-        {
-            activeParts.Clear();
-
-            if (parts != null)
-            {
-                foreach (var part in parts)
-                    activeParts.Add(LayoutPart.Create(part, this));
-            }
-
-            Invalidate();
-        }
-
-        public void ClearPreviewParts()
-        {
-            stationaryParts.Clear();
-            activeParts.Clear();
-            Invalidate();
-        }
-
-        public void AcceptPreviewParts(List<Part> parts)
-        {
-            if (parts != null)
-            {
-                foreach (var part in parts)
-                    Plate.Parts.Add(part);
-            }
-
-            stationaryParts.Clear();
-            activeParts.Clear();
-        }
+        public void SetStationaryParts(List<Part> parts) => previewManager.SetStationaryParts(parts);
+        public void SetActiveParts(List<Part> parts) => previewManager.SetActiveParts(parts);
+        public void ClearPreviewParts() => previewManager.ClearPreviewParts();
+        public void AcceptPreviewParts(List<Part> parts) => previewManager.AcceptPreviewParts(parts);
 
         public async void FillWithProgress(List<Part> groupParts, Box workArea)
         {
@@ -848,14 +616,7 @@ namespace OpenNest.Controls
             }
         }
 
-        public void RemoveSelectedParts()
-        {
-            foreach (var part in SelectedParts)
-                Plate.Parts.Remove(part.BasePart);
-
-            DeselectAll();
-            Invalidate();
-        }
+        public void RemoveSelectedParts() => selection.RemoveSelectedParts();
 
 
         private void redrawTimer_Elapsed(object sender, System.Timers.ElapsedEventArgs e)
@@ -863,6 +624,35 @@ namespace OpenNest.Controls
             Invalidate();
         }
 
+        private void hoverTimer_Elapsed(object sender, System.Timers.ElapsedEventArgs e)
+        {
+            var graphPt = PointControlToGraph(hoverPoint);
+            LayoutPart hitPart = null;
+            try
+            {
+                for (var i = parts.Count - 1; i >= 0; --i)
+                {
+                    if (parts[i].Path.GetBounds().Contains(graphPt) &&
+                        parts[i].Path.IsVisible(graphPt))
+                    {
+                        hitPart = parts[i];
+                        break;
+                    }
+                }
+            }
+            catch (InvalidOperationException)
+            {
+                // GraphicsPath in use by paint thread — skip this hover tick
+                return;
+            }
+
+            hoveredPart = hitPart;
+            showTooltip = hitPart != null;
+
+            if (showTooltip)
+                Invalidate();
+        }
+
         private void plate_PartAdded(object sender, ItemAddedEventArgs<Part> e)
         {
             if (PartAdded != null)
@@ -880,24 +670,9 @@ namespace OpenNest.Controls
             parts.RemoveAll(p => p.BasePart == e.Item);
         }
 
-        public void DeselectAll()
-        {
-            SelectedParts.ForEach(p => p.IsSelected = false);
-            SelectedParts.Clear();
-            SelectionChanged?.Invoke(this, EventArgs.Empty);
-        }
-
-        public void SelectAll()
-        {
-            parts.ForEach(p => p.IsSelected = true);
-            SelectedParts.AddRange(parts);
-            SelectionChanged?.Invoke(this, EventArgs.Empty);
-        }
-
-        public void NotifySelectionChanged()
-        {
-            SelectionChanged?.Invoke(this, EventArgs.Empty);
-        }
+        public void DeselectAll() => selection.DeselectAll();
+        public void SelectAll() => selection.SelectAll();
+        public void NotifySelectionChanged() => selection.NotifySelectionChanged();
 
         public override void ZoomToPoint(Vector pt, float zoomFactor, bool redraw = true)
         {
@@ -930,57 +705,15 @@ namespace OpenNest.Controls
             ZoomToArea(plate.BoundingBox(false), redraw);
         }
 
-        public void PushSelected(PushDirection direction)
-        {
-            var movingParts = SelectedParts.Select(p => p.BasePart).ToList();
-            Compactor.Push(movingParts, Plate, direction);
-            SelectedParts.ForEach(p => p.IsDirty = true);
-            Invalidate();
-        }
+        public void PushSelected(PushDirection direction) => selection.PushSelected(direction);
 
-        private string GetDisplayName(Type type)
-        {
-            var attributes = type.GetCustomAttributes(true);
-
-            foreach (var attr in attributes)
-            {
-                var displayNameAttr = attr as DisplayNameAttribute;
-
-                if (displayNameAttr != null)
-                    return displayNameAttr.DisplayName;
-            }
-
-            return type.Name;
-        }
-
-        public void RotateSelectedParts(double angle)
-        {
-            var parts = SelectedParts.Select(p => p.BasePart).ToList();
-            var bounds = parts.GetBoundingBox();
-            var center = bounds.Center;
-            var anchor = bounds.Location;
-
-            for (var i = 0; i < SelectedParts.Count; ++i)
-            {
-                var part = SelectedParts[i];
-                part.BasePart.Rotate(angle, center);
-            }
-
-            var diff = anchor - parts.GetBoundingBox().Location;
-
-            for (var i = 0; i < SelectedParts.Count; ++i)
-                SelectedParts[i].Offset(diff);
-
-            if (Plate.CutOffs.Count > 0)
-                Plate.RegenerateCutOffs(cutOffSettings);
-        }
+        public void RotateSelectedParts(double angle) => selection.RotateSelectedParts(angle);
 
         protected override void UpdateMatrix()
         {
             base.UpdateMatrix();
             parts.ForEach(p => p.Update(this));
-            stationaryParts.ForEach(p => p.Update(this));
-            activeParts.ForEach(p => p.Update(this));
+            previewManager.Update();
         }
     }
 }

OpenNest/Controls/PreviewManager.cs

@@ -0,0 +1,84 @@
+using System.Collections.Generic;
+using System.Drawing;
+
+namespace OpenNest.Controls
+{
+    internal class PreviewManager
+    {
+        private readonly PlateView view;
+        private readonly List<LayoutPart> stationaryParts = new List<LayoutPart>();
+        private readonly List<LayoutPart> activeParts = new List<LayoutPart>();
+
+        public PreviewManager(PlateView view)
+        {
+            this.view = view;
+        }
+
+        public IReadOnlyList<LayoutPart> PreviewParts =>
+            activeParts.Count > 0 ? activeParts : stationaryParts;
+
+        public Brush PreviewBrush =>
+            activeParts.Count > 0 ? view.ColorScheme.ActivePreviewPartBrush : view.ColorScheme.PreviewPartBrush;
+
+        public Pen PreviewPen =>
+            activeParts.Count > 0 ? view.ColorScheme.ActivePreviewPartPen : view.ColorScheme.PreviewPartPen;
+
+        public void SetStationaryParts(List<Part> parts)
+        {
+            stationaryParts.Clear();
+            activeParts.Clear();
+
+            if (parts != null)
+            {
+                foreach (var part in parts)
+                    stationaryParts.Add(LayoutPart.Create(part, view));
+            }
+
+            view.Invalidate();
+        }
+
+        public void SetActiveParts(List<Part> parts)
+        {
+            activeParts.Clear();
+
+            if (parts != null)
+            {
+                foreach (var part in parts)
+                    activeParts.Add(LayoutPart.Create(part, view));
+            }
+
+            view.Invalidate();
+        }
+
+        public void ClearPreviewParts()
+        {
+            stationaryParts.Clear();
+            activeParts.Clear();
+            view.Invalidate();
+        }
+
+        public void AcceptPreviewParts(List<Part> parts)
+        {
+            if (parts != null)
+            {
+                foreach (var part in parts)
+                    view.Plate.Parts.Add(part);
+            }
+
+            stationaryParts.Clear();
+            activeParts.Clear();
+        }
+
+        public void Update()
+        {
+            stationaryParts.ForEach(p => p.Update(view));
+            activeParts.ForEach(p => p.Update(view));
+        }
+
+        public void Clear()
+        {
+            stationaryParts.Clear();
+            activeParts.Clear();
+        }
+    }
+}

OpenNest/Controls/SelectionManager.cs

@@ -0,0 +1,216 @@
+using OpenNest.Engine.Fill;
+using OpenNest.Geometry;
+using System;
+using System.Collections.Generic;
+using System.Drawing;
+using System.Linq;
+
+namespace OpenNest.Controls
+{
+    internal class SelectionManager
+    {
+        private readonly PlateView view;
+        private readonly List<LayoutPart> selectedParts = new List<LayoutPart>();
+        private readonly List<CutOff> selectedCutOffs = new List<CutOff>();
+
+        public SelectionManager(PlateView view)
+        {
+            this.view = view;
+        }
+
+        public List<LayoutPart> SelectedParts => selectedParts;
+        public List<CutOff> SelectedCutOffs => selectedCutOffs;
+
+        public event EventHandler SelectionChanged;
+
+        public void DeselectAll()
+        {
+            selectedParts.ForEach(p => p.IsSelected = false);
+            selectedParts.Clear();
+            selectedCutOffs.Clear();
+            SelectionChanged?.Invoke(view, EventArgs.Empty);
+        }
+
+        public void DeselectParts()
+        {
+            selectedParts.ForEach(p => p.IsSelected = false);
+            selectedParts.Clear();
+            SelectionChanged?.Invoke(view, EventArgs.Empty);
+        }
+
+        public void DeselectCutOffs()
+        {
+            selectedCutOffs.Clear();
+            view.Invalidate();
+        }
+
+        public void SelectAll()
+        {
+            var parts = view.LayoutParts;
+            parts.ForEach(p => p.IsSelected = true);
+            selectedParts.AddRange(parts);
+            SelectionChanged?.Invoke(view, EventArgs.Empty);
+        }
+
+        public void NotifySelectionChanged()
+        {
+            SelectionChanged?.Invoke(view, EventArgs.Empty);
+        }
+
+        public void DeleteSelected()
+        {
+            if (selectedCutOffs.Count > 0)
+            {
+                foreach (var cutOff in selectedCutOffs)
+                    view.Plate.CutOffs.Remove(cutOff);
+
+                selectedCutOffs.Clear();
+                view.Plate.RegenerateCutOffs(view.CutOffSettings);
+                view.Invalidate();
+            }
+            else
+            {
+                RemoveSelectedParts();
+            }
+        }
+
+        public void RemoveSelectedParts()
+        {
+            foreach (var part in selectedParts)
+                view.Plate.Parts.Remove(part.BasePart);
+
+            DeselectAll();
+            view.Invalidate();
+        }
+
+        public void AlignSelected(AlignType alignType)
+        {
+            if (selectedParts.Count == 0)
+                return;
+
+            AlignSelected(alignType, selectedParts[0]);
+        }
+
+        public void AlignSelected(AlignType alignType, LayoutPart fixedPart)
+        {
+            switch (alignType)
+            {
+                case AlignType.Bottom:
+                    Align.Bottom(fixedPart.BasePart, selectedParts.Select(p => p.BasePart).ToList());
+                    break;
+                case AlignType.Horizontally:
+                    Align.Horizontally(fixedPart.BasePart, selectedParts.Select(p => p.BasePart).ToList());
+                    break;
+                case AlignType.Left:
+                    Align.Left(fixedPart.BasePart, selectedParts.Select(p => p.BasePart).ToList());
+                    break;
+                case AlignType.Right:
+                    Align.Right(fixedPart.BasePart, selectedParts.Select(p => p.BasePart).ToList());
+                    break;
+                case AlignType.Top:
+                    Align.Top(fixedPart.BasePart, selectedParts.Select(p => p.BasePart).ToList());
+                    break;
+                case AlignType.Vertically:
+                    Align.Vertically(fixedPart.BasePart, selectedParts.Select(p => p.BasePart).ToList());
+                    break;
+                case AlignType.EvenlySpaceHorizontally:
+                    Align.EvenlyDistributeHorizontally(selectedParts.Select(p => p.BasePart).ToList());
+                    break;
+                case AlignType.EvenlySpaceVertically:
+                    Align.EvenlyDistributeVertically(selectedParts.Select(p => p.BasePart).ToList());
+                    break;
+                default:
+                    return;
+            }
+
+            selectedParts.ForEach(p => p.IsDirty = true);
+            view.Invalidate();
+        }
+
+        public void RotateSelectedParts(double angle)
+        {
+            var parts = selectedParts.Select(p => p.BasePart).ToList();
+            var bounds = parts.GetBoundingBox();
+            var center = bounds.Center;
+            var anchor = bounds.Location;
+
+            for (var i = 0; i < selectedParts.Count; ++i)
+                selectedParts[i].BasePart.Rotate(angle, center);
+
+            var diff = anchor - parts.GetBoundingBox().Location;
+
+            for (var i = 0; i < selectedParts.Count; ++i)
+                selectedParts[i].Offset(diff);
+
+            if (view.Plate.CutOffs.Count > 0)
+                view.Plate.RegenerateCutOffs(view.CutOffSettings);
+        }
+
+        public void PushSelected(PushDirection direction)
+        {
+            var movingParts = selectedParts.Select(p => p.BasePart).ToList();
+            Compactor.Push(movingParts, view.Plate, direction);
+            selectedParts.ForEach(p => p.IsDirty = true);
+            view.Invalidate();
+        }
+
+        public LayoutPart GetPartAtControlPoint(Point pt)
+        {
+            var pt2 = view.PointControlToGraph(pt);
+            return GetPartAtGraphPoint(pt2);
+        }
+
+        public LayoutPart GetPartAtGraphPoint(PointF pt)
+        {
+            var parts = view.LayoutParts;
+            for (var i = parts.Count - 1; i >= 0; --i)
+            {
+                if (parts[i].Path.IsVisible(pt))
+                    return parts[i];
+            }
+            return null;
+        }
+
+        public LayoutPart GetPartAtPoint(Vector pt)
+        {
+            var pt2 = view.PointWorldToGraph(pt);
+            return GetPartAtGraphPoint(pt2);
+        }
+
+        public IList<LayoutPart> GetPartsFromWindow(RectangleF rect, SelectionType selectionType)
+        {
+            var list = new List<LayoutPart>();
+            var parts = view.LayoutParts;
+
+            if (selectionType == SelectionType.Intersect)
+            {
+                for (var i = 0; i < parts.Count; ++i)
+                {
+                    var part = parts[i];
+                    var region = new Region(part.Path);
+                    if (region.IsVisible(rect))
+                        list.Add(part);
+                    region.Dispose();
+                }
+            }
+            else
+            {
+                for (var i = 0; i < parts.Count; ++i)
+                {
+                    var part = parts[i];
+                    var bounds = part.Path.GetBounds();
+                    if (rect.Contains(bounds))
+                        list.Add(part);
+                }
+            }
+
+            return list;
+        }
+
+        public void Clear()
+        {
+            selectedParts.Clear();
+            selectedCutOffs.Clear();
+        }
+    }
+}

OpenNest/Controls/ShapePreviewControl.cs

@@ -0,0 +1,79 @@
+using System.Drawing;
+using System.Drawing.Drawing2D;
+using System.Windows.Forms;
+
+namespace OpenNest.Controls
+{
+    public class ShapePreviewControl : PlateView
+    {
+        private string[] infoLines;
+
+        public ShapePreviewControl()
+        {
+            DrawOrigin = false;
+            DrawBounds = false;
+            AllowPan = false;
+            AllowSelect = false;
+            AllowZoom = false;
+            AllowDrop = false;
+            BackColor = Color.White;
+        }
+
+        public void SetInfo(params string[] lines)
+        {
+            infoLines = lines;
+            Invalidate();
+        }
+
+        public void ShowDrawing(Drawing drawing)
+        {
+            Plate.Parts.Clear();
+            Plate.Size = new Geometry.Size(0, 0);
+
+            if (drawing?.Program != null)
+            {
+                AddPartFromDrawing(drawing, Geometry.Vector.Zero);
+                ZoomToFit();
+            }
+            else
+            {
+                Invalidate();
+            }
+        }
+
+        protected override void OnResize(System.EventArgs e)
+        {
+            base.OnResize(e);
+
+            if (Plate.Parts.Count > 0)
+                ZoomToFit(false);
+        }
+
+        protected override void OnPaint(PaintEventArgs e)
+        {
+            e.Graphics.SmoothingMode = SmoothingMode.HighQuality;
+
+            e.Graphics.TranslateTransform(origin.X, origin.Y);
+            Renderer.DrawPlate(e.Graphics);
+            Renderer.DrawParts(e.Graphics);
+            e.Graphics.ResetTransform();
+
+            PaintInfo(e.Graphics);
+        }
+
+        private void PaintInfo(Graphics g)
+        {
+            if (infoLines == null) return;
+
+            var lineHeight = Font.GetHeight(g) + 1;
+            var y = 4f;
+
+            foreach (var line in infoLines)
+            {
+                if (string.IsNullOrEmpty(line)) continue;
+                g.DrawString(line, Font, Brushes.Black, 4, y);
+                y += lineHeight;
+            }
+        }
+    }
+}

OpenNest/Forms/AutoNestForm.Designer.cs

@@ -17,13 +17,20 @@ namespace OpenNest.Forms
 
         private void InitializeComponent()
         {
-            this.engineLabel = new System.Windows.Forms.Label();
-            this.engineComboBox = new System.Windows.Forms.ComboBox();
-            this.partsGroup = new System.Windows.Forms.GroupBox();
+            this.tabControl = new System.Windows.Forms.TabControl();
+            this.partsTab = new System.Windows.Forms.TabPage();
+            this.platesTab = new System.Windows.Forms.TabPage();
             this.partsGrid = new System.Windows.Forms.DataGridView();
             this.summaryLabel = new System.Windows.Forms.Label();
-            this.optionsGroup = new System.Windows.Forms.GroupBox();
+            this.engineLabel = new System.Windows.Forms.Label();
+            this.engineComboBox = new System.Windows.Forms.ComboBox();
             this.createNewPlatesAsNeededBox = new System.Windows.Forms.CheckBox();
+            this.partFirstGroup = new System.Windows.Forms.GroupBox();
+            this.partFirstCheckBox = new System.Windows.Forms.CheckBox();
+            this.sortOrderLabel = new System.Windows.Forms.Label();
+            this.sortOrderComboBox = new System.Windows.Forms.ComboBox();
+            this.minRemnantLabel = new System.Windows.Forms.Label();
+            this.minRemnantBox = new System.Windows.Forms.TextBox();
             this.plateOptimizerGroup = new System.Windows.Forms.GroupBox();
             this.optimizePlateSizeBox = new System.Windows.Forms.CheckBox();
             this.plateGrid = new System.Windows.Forms.DataGridView();
@@ -33,42 +40,53 @@ namespace OpenNest.Forms
             this.buttonPanel = new System.Windows.Forms.Panel();
             this.acceptButton = new System.Windows.Forms.Button();
             this.cancelButton = new System.Windows.Forms.Button();
+            this.tabControl.SuspendLayout();
+            this.partsTab.SuspendLayout();
+            this.platesTab.SuspendLayout();
             ((System.ComponentModel.ISupportInitialize)(this.partsGrid)).BeginInit();
             ((System.ComponentModel.ISupportInitialize)(this.plateGrid)).BeginInit();
-            this.partsGroup.SuspendLayout();
-            this.optionsGroup.SuspendLayout();
+            this.partFirstGroup.SuspendLayout();
             this.plateOptimizerGroup.SuspendLayout();
             this.buttonPanel.SuspendLayout();
             this.SuspendLayout();
             //
-            // engineLabel
+            // tabControl
             //
-            this.engineLabel.AutoSize = true;
-            this.engineLabel.Location = new System.Drawing.Point(12, 15);
-            this.engineLabel.Name = "engineLabel";
-            this.engineLabel.Size = new System.Drawing.Size(82, 16);
-            this.engineLabel.TabIndex = 0;
-            this.engineLabel.Text = "Nest Engine:";
+            this.tabControl.Anchor = ((System.Windows.Forms.AnchorStyles)(((System.Windows.Forms.AnchorStyles.Top | System.Windows.Forms.AnchorStyles.Left) | System.Windows.Forms.AnchorStyles.Right)));
+            this.tabControl.Controls.Add(this.partsTab);
+            this.tabControl.Controls.Add(this.platesTab);
+            this.tabControl.Location = new System.Drawing.Point(12, 12);
+            this.tabControl.Name = "tabControl";
+            this.tabControl.SelectedIndex = 0;
+            this.tabControl.Size = new System.Drawing.Size(556, 490);
+            this.tabControl.TabIndex = 0;
             //
-            // engineComboBox
+            // partsTab
             //
-            this.engineComboBox.DropDownStyle = System.Windows.Forms.ComboBoxStyle.DropDownList;
-            this.engineComboBox.Location = new System.Drawing.Point(100, 12);
-            this.engineComboBox.Name = "engineComboBox";
-            this.engineComboBox.Size = new System.Drawing.Size(200, 24);
-            this.engineComboBox.TabIndex = 1;
+            this.partsTab.Controls.Add(this.partsGrid);
+            this.partsTab.Controls.Add(this.summaryLabel);
+            this.partsTab.Location = new System.Drawing.Point(4, 25);
+            this.partsTab.Name = "partsTab";
+            this.partsTab.Padding = new System.Windows.Forms.Padding(6);
+            this.partsTab.Size = new System.Drawing.Size(548, 461);
+            this.partsTab.TabIndex = 0;
+            this.partsTab.Text = "Parts";
+            this.partsTab.UseVisualStyleBackColor = true;
             //
-            // partsGroup
+            // platesTab
             //
-            this.partsGroup.Anchor = ((System.Windows.Forms.AnchorStyles)(((System.Windows.Forms.AnchorStyles.Top | System.Windows.Forms.AnchorStyles.Left) | System.Windows.Forms.AnchorStyles.Right)));
-            this.partsGroup.Controls.Add(this.partsGrid);
-            this.partsGroup.Controls.Add(this.summaryLabel);
-            this.partsGroup.Location = new System.Drawing.Point(12, 42);
-            this.partsGroup.Name = "partsGroup";
-            this.partsGroup.Size = new System.Drawing.Size(556, 210);
-            this.partsGroup.TabIndex = 2;
-            this.partsGroup.TabStop = false;
-            this.partsGroup.Text = "Parts";
+            this.platesTab.Controls.Add(this.engineLabel);
+            this.platesTab.Controls.Add(this.engineComboBox);
+            this.platesTab.Controls.Add(this.createNewPlatesAsNeededBox);
+            this.platesTab.Controls.Add(this.partFirstGroup);
+            this.platesTab.Controls.Add(this.plateOptimizerGroup);
+            this.platesTab.Location = new System.Drawing.Point(4, 25);
+            this.platesTab.Name = "platesTab";
+            this.platesTab.Padding = new System.Windows.Forms.Padding(6);
+            this.platesTab.Size = new System.Drawing.Size(548, 461);
+            this.platesTab.TabIndex = 1;
+            this.platesTab.Text = "Plates";
+            this.platesTab.UseVisualStyleBackColor = true;
             //
             // partsGrid
             //
@@ -78,43 +96,108 @@ namespace OpenNest.Forms
             this.partsGrid.Anchor = ((System.Windows.Forms.AnchorStyles)(((System.Windows.Forms.AnchorStyles.Top | System.Windows.Forms.AnchorStyles.Left) | System.Windows.Forms.AnchorStyles.Right)));
             this.partsGrid.BorderStyle = System.Windows.Forms.BorderStyle.FixedSingle;
             this.partsGrid.ColumnHeadersHeightSizeMode = System.Windows.Forms.DataGridViewColumnHeadersHeightSizeMode.AutoSize;
-            this.partsGrid.Location = new System.Drawing.Point(10, 22);
+            this.partsGrid.Location = new System.Drawing.Point(10, 10);
             this.partsGrid.Name = "partsGrid";
             this.partsGrid.RowHeadersVisible = false;
             this.partsGrid.AutoGenerateColumns = false;
-            this.partsGrid.Size = new System.Drawing.Size(536, 160);
+            this.partsGrid.Size = new System.Drawing.Size(528, 420);
             this.partsGrid.TabIndex = 0;
             //
             // summaryLabel
             //
             this.summaryLabel.AutoSize = true;
             this.summaryLabel.ForeColor = System.Drawing.SystemColors.GrayText;
-            this.summaryLabel.Location = new System.Drawing.Point(10, 188);
+            this.summaryLabel.Location = new System.Drawing.Point(10, 436);
             this.summaryLabel.Name = "summaryLabel";
             this.summaryLabel.Size = new System.Drawing.Size(0, 16);
             this.summaryLabel.TabIndex = 1;
             //
-            // optionsGroup
+            // engineLabel
             //
-            this.optionsGroup.Anchor = ((System.Windows.Forms.AnchorStyles)(((System.Windows.Forms.AnchorStyles.Top | System.Windows.Forms.AnchorStyles.Left) | System.Windows.Forms.AnchorStyles.Right)));
-            this.optionsGroup.Controls.Add(this.createNewPlatesAsNeededBox);
-            this.optionsGroup.Location = new System.Drawing.Point(12, 258);
-            this.optionsGroup.Name = "optionsGroup";
-            this.optionsGroup.Size = new System.Drawing.Size(556, 48);
-            this.optionsGroup.TabIndex = 3;
-            this.optionsGroup.TabStop = false;
-            this.optionsGroup.Text = "Options";
+            this.engineLabel.AutoSize = true;
+            this.engineLabel.Location = new System.Drawing.Point(10, 15);
+            this.engineLabel.Name = "engineLabel";
+            this.engineLabel.Size = new System.Drawing.Size(82, 16);
+            this.engineLabel.TabIndex = 0;
+            this.engineLabel.Text = "Nest Engine:";
+            //
+            // engineComboBox
+            //
+            this.engineComboBox.DropDownStyle = System.Windows.Forms.ComboBoxStyle.DropDownList;
+            this.engineComboBox.Location = new System.Drawing.Point(98, 12);
+            this.engineComboBox.Name = "engineComboBox";
+            this.engineComboBox.Size = new System.Drawing.Size(200, 24);
+            this.engineComboBox.TabIndex = 1;
             //
             // createNewPlatesAsNeededBox
             //
             this.createNewPlatesAsNeededBox.AutoSize = true;
-            this.createNewPlatesAsNeededBox.Location = new System.Drawing.Point(10, 22);
+            this.createNewPlatesAsNeededBox.Location = new System.Drawing.Point(10, 44);
             this.createNewPlatesAsNeededBox.Name = "createNewPlatesAsNeededBox";
             this.createNewPlatesAsNeededBox.Size = new System.Drawing.Size(202, 20);
-            this.createNewPlatesAsNeededBox.TabIndex = 0;
+            this.createNewPlatesAsNeededBox.TabIndex = 2;
             this.createNewPlatesAsNeededBox.Text = "Create new plates as needed";
             this.createNewPlatesAsNeededBox.UseVisualStyleBackColor = true;
             //
+            // partFirstGroup
+            //
+            this.partFirstGroup.Anchor = ((System.Windows.Forms.AnchorStyles)(((System.Windows.Forms.AnchorStyles.Top | System.Windows.Forms.AnchorStyles.Left) | System.Windows.Forms.AnchorStyles.Right)));
+            this.partFirstGroup.Controls.Add(this.partFirstCheckBox);
+            this.partFirstGroup.Controls.Add(this.sortOrderLabel);
+            this.partFirstGroup.Controls.Add(this.sortOrderComboBox);
+            this.partFirstGroup.Controls.Add(this.minRemnantLabel);
+            this.partFirstGroup.Controls.Add(this.minRemnantBox);
+            this.partFirstGroup.Location = new System.Drawing.Point(10, 72);
+            this.partFirstGroup.Name = "partFirstGroup";
+            this.partFirstGroup.Size = new System.Drawing.Size(528, 80);
+            this.partFirstGroup.TabIndex = 3;
+            this.partFirstGroup.TabStop = false;
+            this.partFirstGroup.Text = "      Part-First Mode";
+            //
+            // partFirstCheckBox
+            //
+            this.partFirstCheckBox.AutoSize = true;
+            this.partFirstCheckBox.Location = new System.Drawing.Point(10, 0);
+            this.partFirstCheckBox.Name = "partFirstCheckBox";
+            this.partFirstCheckBox.Size = new System.Drawing.Size(15, 14);
+            this.partFirstCheckBox.TabIndex = 0;
+            this.partFirstCheckBox.UseVisualStyleBackColor = true;
+            this.partFirstCheckBox.CheckedChanged += new System.EventHandler(this.partFirstCheckBox_CheckedChanged);
+            //
+            // sortOrderLabel
+            //
+            this.sortOrderLabel.AutoSize = true;
+            this.sortOrderLabel.Location = new System.Drawing.Point(10, 26);
+            this.sortOrderLabel.Name = "sortOrderLabel";
+            this.sortOrderLabel.Size = new System.Drawing.Size(75, 16);
+            this.sortOrderLabel.TabIndex = 1;
+            this.sortOrderLabel.Text = "Sort Order:";
+            //
+            // sortOrderComboBox
+            //
+            this.sortOrderComboBox.DropDownStyle = System.Windows.Forms.ComboBoxStyle.DropDownList;
+            this.sortOrderComboBox.Location = new System.Drawing.Point(100, 23);
+            this.sortOrderComboBox.Name = "sortOrderComboBox";
+            this.sortOrderComboBox.Size = new System.Drawing.Size(180, 24);
+            this.sortOrderComboBox.TabIndex = 2;
+            //
+            // minRemnantLabel
+            //
+            this.minRemnantLabel.AutoSize = true;
+            this.minRemnantLabel.Location = new System.Drawing.Point(10, 54);
+            this.minRemnantLabel.Name = "minRemnantLabel";
+            this.minRemnantLabel.Size = new System.Drawing.Size(117, 16);
+            this.minRemnantLabel.TabIndex = 3;
+            this.minRemnantLabel.Text = "Min Remnant Size:";
+            //
+            // minRemnantBox
+            //
+            this.minRemnantBox.Location = new System.Drawing.Point(133, 51);
+            this.minRemnantBox.Name = "minRemnantBox";
+            this.minRemnantBox.Size = new System.Drawing.Size(60, 22);
+            this.minRemnantBox.TabIndex = 4;
+            this.minRemnantBox.Text = "12";
+            //
             // plateOptimizerGroup
             //
             this.plateOptimizerGroup.Anchor = ((System.Windows.Forms.AnchorStyles)(((System.Windows.Forms.AnchorStyles.Top | System.Windows.Forms.AnchorStyles.Left) | System.Windows.Forms.AnchorStyles.Right)));
@@ -123,9 +206,9 @@ namespace OpenNest.Forms
             this.plateOptimizerGroup.Controls.Add(this.salvageRateLabel);
             this.plateOptimizerGroup.Controls.Add(this.salvageRateBox);
             this.plateOptimizerGroup.Controls.Add(this.salvageRatePercentLabel);
-            this.plateOptimizerGroup.Location = new System.Drawing.Point(12, 312);
+            this.plateOptimizerGroup.Location = new System.Drawing.Point(10, 158);
             this.plateOptimizerGroup.Name = "plateOptimizerGroup";
-            this.plateOptimizerGroup.Size = new System.Drawing.Size(556, 188);
+            this.plateOptimizerGroup.Size = new System.Drawing.Size(528, 188);
             this.plateOptimizerGroup.TabIndex = 4;
             this.plateOptimizerGroup.TabStop = false;
             this.plateOptimizerGroup.Text = "      Plate Optimizer";
@@ -150,7 +233,7 @@ namespace OpenNest.Forms
             this.plateGrid.Name = "plateGrid";
             this.plateGrid.RowHeadersVisible = false;
             this.plateGrid.AutoGenerateColumns = false;
-            this.plateGrid.Size = new System.Drawing.Size(536, 130);
+            this.plateGrid.Size = new System.Drawing.Size(508, 130);
             this.plateGrid.TabIndex = 1;
             //
             // salvageRateLabel
@@ -187,7 +270,7 @@ namespace OpenNest.Forms
             this.buttonPanel.Location = new System.Drawing.Point(0, 506);
             this.buttonPanel.Name = "buttonPanel";
             this.buttonPanel.Size = new System.Drawing.Size(580, 50);
-            this.buttonPanel.TabIndex = 5;
+            this.buttonPanel.TabIndex = 1;
             //
             // acceptButton
             //
@@ -217,11 +300,7 @@ namespace OpenNest.Forms
             this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.None;
             this.CancelButton = this.cancelButton;
             this.ClientSize = new System.Drawing.Size(580, 556);
-            this.Controls.Add(this.engineLabel);
-            this.Controls.Add(this.engineComboBox);
-            this.Controls.Add(this.partsGroup);
-            this.Controls.Add(this.optionsGroup);
-            this.Controls.Add(this.plateOptimizerGroup);
+            this.Controls.Add(this.tabControl);
             this.Controls.Add(this.buttonPanel);
             this.Font = new System.Drawing.Font("Microsoft Sans Serif", 9.75F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((byte)(0)));
             this.FormBorderStyle = System.Windows.Forms.FormBorderStyle.FixedDialog;
@@ -232,28 +311,37 @@ namespace OpenNest.Forms
             this.ShowInTaskbar = false;
             this.StartPosition = System.Windows.Forms.FormStartPosition.CenterParent;
             this.Text = "AutoNest";
+            this.tabControl.ResumeLayout(false);
+            this.partsTab.ResumeLayout(false);
+            this.partsTab.PerformLayout();
+            this.platesTab.ResumeLayout(false);
+            this.platesTab.PerformLayout();
             ((System.ComponentModel.ISupportInitialize)(this.partsGrid)).EndInit();
             ((System.ComponentModel.ISupportInitialize)(this.plateGrid)).EndInit();
-            this.partsGroup.ResumeLayout(false);
-            this.partsGroup.PerformLayout();
-            this.optionsGroup.ResumeLayout(false);
-            this.optionsGroup.PerformLayout();
+            this.partFirstGroup.ResumeLayout(false);
+            this.partFirstGroup.PerformLayout();
             this.plateOptimizerGroup.ResumeLayout(false);
             this.plateOptimizerGroup.PerformLayout();
             this.buttonPanel.ResumeLayout(false);
             this.ResumeLayout(false);
-            this.PerformLayout();
         }
 
         #endregion
 
-        private System.Windows.Forms.Label engineLabel;
-        private System.Windows.Forms.ComboBox engineComboBox;
-        private System.Windows.Forms.GroupBox partsGroup;
+        private System.Windows.Forms.TabControl tabControl;
+        private System.Windows.Forms.TabPage partsTab;
+        private System.Windows.Forms.TabPage platesTab;
         private System.Windows.Forms.DataGridView partsGrid;
         private System.Windows.Forms.Label summaryLabel;
-        private System.Windows.Forms.GroupBox optionsGroup;
+        private System.Windows.Forms.Label engineLabel;
+        private System.Windows.Forms.ComboBox engineComboBox;
         private System.Windows.Forms.CheckBox createNewPlatesAsNeededBox;
+        private System.Windows.Forms.GroupBox partFirstGroup;
+        private System.Windows.Forms.CheckBox partFirstCheckBox;
+        private System.Windows.Forms.Label sortOrderLabel;
+        private System.Windows.Forms.ComboBox sortOrderComboBox;
+        private System.Windows.Forms.Label minRemnantLabel;
+        private System.Windows.Forms.TextBox minRemnantBox;
         private System.Windows.Forms.GroupBox plateOptimizerGroup;
         private System.Windows.Forms.CheckBox optimizePlateSizeBox;
         private System.Windows.Forms.DataGridView plateGrid;

OpenNest/Forms/AutoNestForm.cs

@@ -22,6 +22,11 @@ namespace OpenNest.Forms
             LoadDefaultPlateOptions();
             SetPlateOptimizerVisible(false);
 
+            sortOrderComboBox.Items.Add("Bounding Box Area");
+            sortOrderComboBox.Items.Add("Size");
+            sortOrderComboBox.SelectedIndex = 0;
+            SetPartFirstVisible(false);
+
             partsGrid.DataError += PartsGrid_DataError;
         }
 
@@ -54,6 +59,32 @@ namespace OpenNest.Forms
             set { salvageRateBox.Text = (value * 100).ToString("F0"); }
         }
 
+        public bool PartFirstMode
+        {
+            get { return partFirstCheckBox.Checked; }
+            set { partFirstCheckBox.Checked = value; }
+        }
+
+        public PartSortOrder SortOrder
+        {
+            get
+            {
+                if (sortOrderComboBox.SelectedItem is string s && s == "Size")
+                    return PartSortOrder.Size;
+                return PartSortOrder.BoundingBoxArea;
+            }
+        }
+
+        public double MinRemnantSize
+        {
+            get
+            {
+                if (double.TryParse(minRemnantBox.Text, out var val) && val > 0)
+                    return val;
+                return 12.0;
+            }
+        }
+
         private void LoadEngines()
         {
             foreach (var engine in NestEngineRegistry.AvailableEngines)
@@ -242,6 +273,19 @@ namespace OpenNest.Forms
             salvageRatePercentLabel.Visible = visible;
         }
 
+        private void partFirstCheckBox_CheckedChanged(object sender, EventArgs e)
+        {
+            SetPartFirstVisible(partFirstCheckBox.Checked);
+        }
+
+        private void SetPartFirstVisible(bool visible)
+        {
+            sortOrderLabel.Visible = visible;
+            sortOrderComboBox.Visible = visible;
+            minRemnantLabel.Visible = visible;
+            minRemnantBox.Visible = visible;
+        }
+
         private void UpdateSummary()
         {
             var gridItems = partsGrid.DataSource as List<DataGridViewItem>;

OpenNest/Forms/BendLineDialog.resx

@@ -0,0 +1,120 @@
+<?xml version="1.0" encoding="utf-8"?>
+<root>
+  <!-- 
+    Microsoft ResX Schema 
+    
+    Version 2.0
+    
+    The primary goals of this format is to allow a simple XML format 
+    that is mostly human readable. The generation and parsing of the 
+    various data types are done through the TypeConverter classes 
+    associated with the data types.
+    
+    Example:
+    
+    ... ado.net/XML headers & schema ...
+    <resheader name="resmimetype">text/microsoft-resx</resheader>
+    <resheader name="version">2.0</resheader>
+    <resheader name="reader">System.Resources.ResXResourceReader, System.Windows.Forms, ...</resheader>
+    <resheader name="writer">System.Resources.ResXResourceWriter, System.Windows.Forms, ...</resheader>
+    <data name="Name1"><value>this is my long string</value><comment>this is a comment</comment></data>
+    <data name="Color1" type="System.Drawing.Color, System.Drawing">Blue</data>
+    <data name="Bitmap1" mimetype="application/x-microsoft.net.object.binary.base64">
+        <value>[base64 mime encoded serialized .NET Framework object]</value>
+    </data>
+    <data name="Icon1" type="System.Drawing.Icon, System.Drawing" mimetype="application/x-microsoft.net.object.bytearray.base64">
+        <value>[base64 mime encoded string representing a byte array form of the .NET Framework object]</value>
+        <comment>This is a comment</comment>
+    </data>
+                
+    There are any number of "resheader" rows that contain simple 
+    name/value pairs.
+    
+    Each data row contains a name, and value. The row also contains a 
+    type or mimetype. Type corresponds to a .NET class that support 
+    text/value conversion through the TypeConverter architecture. 
+    Classes that don't support this are serialized and stored with the 
+    mimetype set.
+    
+    The mimetype is used for serialized objects, and tells the 
+    ResXResourceReader how to depersist the object. This is currently not 
+    extensible. For a given mimetype the value must be set accordingly:
+    
+    Note - application/x-microsoft.net.object.binary.base64 is the format 
+    that the ResXResourceWriter will generate, however the reader can 
+    read any of the formats listed below.
+    
+    mimetype: application/x-microsoft.net.object.binary.base64
+    value   : The object must be serialized with 
+            : System.Runtime.Serialization.Formatters.Binary.BinaryFormatter
+            : and then encoded with base64 encoding.
+    
+    mimetype: application/x-microsoft.net.object.soap.base64
+    value   : The object must be serialized with 
+            : System.Runtime.Serialization.Formatters.Soap.SoapFormatter
+            : and then encoded with base64 encoding.
+
+    mimetype: application/x-microsoft.net.object.bytearray.base64
+    value   : The object must be serialized into a byte array 
+            : using a System.ComponentModel.TypeConverter
+            : and then encoded with base64 encoding.
+    -->
+  <xsd:schema id="root" xmlns="" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:msdata="urn:schemas-microsoft-com:xml-msdata">
+    <xsd:import namespace="http://www.w3.org/XML/1998/namespace" />
+    <xsd:element name="root" msdata:IsDataSet="true">
+      <xsd:complexType>
+        <xsd:choice maxOccurs="unbounded">
+          <xsd:element name="metadata">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" />
+              </xsd:sequence>
+              <xsd:attribute name="name" use="required" type="xsd:string" />
+              <xsd:attribute name="type" type="xsd:string" />
+              <xsd:attribute name="mimetype" type="xsd:string" />
+              <xsd:attribute ref="xml:space" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="assembly">
+            <xsd:complexType>
+              <xsd:attribute name="alias" type="xsd:string" />
+              <xsd:attribute name="name" type="xsd:string" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="data">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />
+                <xsd:element name="comment" type="xsd:string" minOccurs="0" msdata:Ordinal="2" />
+              </xsd:sequence>
+              <xsd:attribute name="name" type="xsd:string" use="required" msdata:Ordinal="1" />
+              <xsd:attribute name="type" type="xsd:string" msdata:Ordinal="3" />
+              <xsd:attribute name="mimetype" type="xsd:string" msdata:Ordinal="4" />
+              <xsd:attribute ref="xml:space" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="resheader">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />
+              </xsd:sequence>
+              <xsd:attribute name="name" type="xsd:string" use="required" />
+            </xsd:complexType>
+          </xsd:element>
+        </xsd:choice>
+      </xsd:complexType>
+    </xsd:element>
+  </xsd:schema>
+  <resheader name="resmimetype">
+    <value>text/microsoft-resx</value>
+  </resheader>
+  <resheader name="version">
+    <value>2.0</value>
+  </resheader>
+  <resheader name="reader">
+    <value>System.Resources.ResXResourceReader, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
+  </resheader>
+  <resheader name="writer">
+    <value>System.Resources.ResXResourceWriter, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
+  </resheader>
+</root>

OpenNest/Forms/BomImportForm.cs

@@ -1,7 +1,9 @@
+using OpenNest.Bending;
 using OpenNest.CNC;
 using OpenNest.Converters;
 using OpenNest.Geometry;
 using OpenNest.IO;
+using OpenNest.IO.Bending;
 using OpenNest.IO.Bom;
 using System;
 using System.Collections.Generic;
@@ -16,8 +18,9 @@ namespace OpenNest.Forms
     public partial class BomImportForm : Form
     {
         private List<BomPartRow> _parts;
-        private Dictionary<string, (double Width, double Length)> _plateSizes;
+        private Dictionary<string, GroupSettings> _groupSettings;
         private bool _suppressRegroup;
+        private Nest.PlateSettings _templateDefaults;
 
         public Form MdiParentForm { get; set; }
 
@@ -25,7 +28,38 @@ namespace OpenNest.Forms
         {
             InitializeComponent();
             _parts = new List<BomPartRow>();
-            _plateSizes = new Dictionary<string, (double, double)>();
+            _groupSettings = new Dictionary<string, GroupSettings>();
+            _templateDefaults = LoadTemplateDefaults();
+            ApplyTemplateDefaults();
+        }
+
+        private Nest.PlateSettings LoadTemplateDefaults()
+        {
+            var templatePath = Properties.Settings.Default.NestTemplatePath;
+            if (File.Exists(templatePath))
+            {
+                try
+                {
+                    var nest = new NestReader(templatePath).Read();
+                    return nest.PlateDefaults;
+                }
+                catch { }
+            }
+
+            // Fallback defaults matching CreateDefaultNest
+            return new Nest.PlateSettings
+            {
+                Size = new Geometry.Size(100, 100),
+                Quadrant = 1,
+                PartSpacing = 1,
+                EdgeSpacing = new Spacing(1, 1, 1, 1),
+            };
+        }
+
+        private void ApplyTemplateDefaults()
+        {
+            txtPlateWidth.Text = _templateDefaults.Size.Width.ToString("0.####");
+            txtPlateLength.Text = _templateDefaults.Size.Length.ToString("0.####");
         }
 
         #region File Browsing
@@ -154,7 +188,7 @@ namespace OpenNest.Forms
                 _parts.Add(row);
             }
 
-            _plateSizes.Clear();
+            _groupSettings.Clear();
         }
 
         #endregion
@@ -244,11 +278,11 @@ namespace OpenNest.Forms
 
         private void RebuildGroups()
         {
-            // Save existing plate sizes before rebuilding
-            SavePlateSizes();
+            // Save existing settings before rebuilding
+            SaveGroupSettings();
 
-            var defaultWidth = double.TryParse(txtPlateWidth.Text, out var w) ? w : 60;
-            var defaultLength = double.TryParse(txtPlateLength.Text, out var l) ? l : 120;
+            var defaultWidth = double.TryParse(txtPlateWidth.Text, out var w) ? w : _templateDefaults.Size.Width;
+            var defaultLength = double.TryParse(txtPlateLength.Text, out var l) ? l : _templateDefaults.Size.Length;
 
             var groups = _parts
                 .Where(p => p.IsEditable
@@ -270,6 +304,11 @@ namespace OpenNest.Forms
             table.Columns.Add("Total Qty", typeof(int));
             table.Columns.Add("Plate Width", typeof(double));
             table.Columns.Add("Plate Length", typeof(double));
+            table.Columns.Add("Part Spacing", typeof(double));
+            table.Columns.Add("Edge Left", typeof(double));
+            table.Columns.Add("Edge Bottom", typeof(double));
+            table.Columns.Add("Edge Right", typeof(double));
+            table.Columns.Add("Edge Top", typeof(double));
 
             foreach (var group in groups)
             {
@@ -277,23 +316,27 @@ namespace OpenNest.Forms
                 var thickness = group.Key.Thickness;
                 var key = GroupKey(material, thickness);
 
-                var plateWidth = _plateSizes.TryGetValue(key, out var size) ? size.Width : defaultWidth;
-                var plateLength = _plateSizes.TryGetValue(key, out _) ? size.Length : defaultLength;
+                var existing = _groupSettings.TryGetValue(key, out var gs);
 
                 table.Rows.Add(
                     material,
                     thickness,
                     group.Count(),
                     group.Sum(p => p.Qty ?? 0),
-                    plateWidth,
-                    plateLength
+                    existing ? gs.PlateWidth : defaultWidth,
+                    existing ? gs.PlateLength : defaultLength,
+                    existing ? gs.PartSpacing : _templateDefaults.PartSpacing,
+                    existing ? gs.EdgeLeft : _templateDefaults.EdgeSpacing.Left,
+                    existing ? gs.EdgeBottom : _templateDefaults.EdgeSpacing.Bottom,
+                    existing ? gs.EdgeRight : _templateDefaults.EdgeSpacing.Right,
+                    existing ? gs.EdgeTop : _templateDefaults.EdgeSpacing.Top
                 );
             }
 
             dgvGroups.DataSource = table;
 
             // Material, Thickness, Parts, Total Qty are read-only
-            if (dgvGroups.Columns.Count >= 6)
+            if (dgvGroups.Columns.Count > 0)
             {
                 dgvGroups.Columns["Material"].ReadOnly = true;
                 dgvGroups.Columns["Thickness"].ReadOnly = true;
@@ -304,22 +347,28 @@ namespace OpenNest.Forms
             btnCreateNests.Enabled = table.Rows.Count > 0;
         }
 
-        private void SavePlateSizes()
+        private void SaveGroupSettings()
         {
             if (dgvGroups.DataSource is not DataTable table)
                 return;
 
-            _plateSizes.Clear();
+            _groupSettings.Clear();
             foreach (DataRow row in table.Rows)
             {
                 var material = row["Material"]?.ToString() ?? "";
                 var thickness = row["Thickness"] is double t ? t : 0;
                 var key = GroupKey(material, thickness);
 
-                var width = row["Plate Width"] is double pw ? pw : 60;
-                var length = row["Plate Length"] is double pl ? pl : 120;
-
-                _plateSizes[key] = (width, length);
+                _groupSettings[key] = new GroupSettings
+                {
+                    PlateWidth = row["Plate Width"] is double pw ? pw : _templateDefaults.Size.Width,
+                    PlateLength = row["Plate Length"] is double pl ? pl : _templateDefaults.Size.Length,
+                    PartSpacing = row["Part Spacing"] is double ps ? ps : _templateDefaults.PartSpacing,
+                    EdgeLeft = row["Edge Left"] is double el ? el : _templateDefaults.EdgeSpacing.Left,
+                    EdgeBottom = row["Edge Bottom"] is double eb ? eb : _templateDefaults.EdgeSpacing.Bottom,
+                    EdgeRight = row["Edge Right"] is double er ? er : _templateDefaults.EdgeSpacing.Right,
+                    EdgeTop = row["Edge Top"] is double et ? et : _templateDefaults.EdgeSpacing.Top,
+                };
             }
         }
 
@@ -356,11 +405,11 @@ namespace OpenNest.Forms
             if (_parts == null || _parts.Count == 0)
                 return;
 
-            // Save latest plate size edits
-            SavePlateSizes();
+            // Save latest group edits
+            SaveGroupSettings();
 
-            var defaultWidth = double.TryParse(txtPlateWidth.Text, out var dw) ? dw : 60;
-            var defaultLength = double.TryParse(txtPlateLength.Text, out var dl) ? dl : 120;
+            var defaultWidth = double.TryParse(txtPlateWidth.Text, out var dw) ? dw : _templateDefaults.Size.Width;
+            var defaultLength = double.TryParse(txtPlateLength.Text, out var dl) ? dl : _templateDefaults.Size.Length;
 
             var groups = _parts
                 .Where(p => p.IsEditable
@@ -382,7 +431,6 @@ namespace OpenNest.Forms
             }
 
             var jobName = txtJobName.Text.Trim();
-            var importer = new DxfImporter();
             var nestsCreated = 0;
             var importErrors = new List<string>();
 
@@ -392,8 +440,14 @@ namespace OpenNest.Forms
                 var thickness = group.Key.Thickness;
                 var key = GroupKey(material, thickness);
 
-                var plateWidth = _plateSizes.TryGetValue(key, out var size) ? size.Width : defaultWidth;
-                var plateLength = _plateSizes.TryGetValue(key, out _) ? size.Length : defaultLength;
+                var hasSettings = _groupSettings.TryGetValue(key, out var gs);
+                var plateWidth = hasSettings ? gs.PlateWidth : defaultWidth;
+                var plateLength = hasSettings ? gs.PlateLength : defaultLength;
+                var partSpacing = hasSettings ? gs.PartSpacing : _templateDefaults.PartSpacing;
+                var edgeLeft = hasSettings ? gs.EdgeLeft : _templateDefaults.EdgeSpacing.Left;
+                var edgeBottom = hasSettings ? gs.EdgeBottom : _templateDefaults.EdgeSpacing.Bottom;
+                var edgeRight = hasSettings ? gs.EdgeRight : _templateDefaults.EdgeSpacing.Right;
+                var edgeTop = hasSettings ? gs.EdgeTop : _templateDefaults.EdgeSpacing.Top;
 
                 var nestName = $"{jobName} - {thickness:0.###} {material}";
                 var nest = new Nest(nestName);
@@ -402,9 +456,9 @@ namespace OpenNest.Forms
                 nest.PlateDefaults.Size = new Geometry.Size(plateWidth, plateLength);
                 nest.Thickness = thickness;
                 nest.Material = new Material(material);
-                nest.PlateDefaults.Quadrant = 1;
-                nest.PlateDefaults.PartSpacing = 1;
-                nest.PlateDefaults.EdgeSpacing = new Spacing(1, 1, 1, 1);
+                nest.PlateDefaults.Quadrant = _templateDefaults.Quadrant;
+                nest.PlateDefaults.PartSpacing = partSpacing;
+                nest.PlateDefaults.EdgeSpacing = new Spacing(edgeLeft, edgeBottom, edgeRight, edgeTop);
 
                 foreach (var part in group)
                 {
@@ -416,7 +470,12 @@ namespace OpenNest.Forms
 
                     try
                     {
-                        var result = importer.Import(part.DxfPath);
+                        var result = Dxf.Import(part.DxfPath);
+
+                        var bends = new List<Bend>();
+                        if (result.Document != null)
+                            bends = BendDetectorRegistry.AutoDetect(result.Document);
+                        Bend.UpdateEtchEntities(result.Entities, bends);
 
                         var drawingName = Path.GetFileNameWithoutExtension(part.DxfPath);
                         var drawing = new Drawing(drawingName);
@@ -424,6 +483,8 @@ namespace OpenNest.Forms
                         drawing.Source.Path = part.DxfPath;
                         drawing.Quantity.Required = part.Qty ?? 1;
                         drawing.Material = new Material(material);
+                        if (bends.Count > 0)
+                            drawing.Bends.AddRange(bends);
 
                         var normalized = ShapeProfile.NormalizeEntities(result.Entities);
                         var pgm = ConvertGeometry.ToProgram(normalized);
@@ -487,4 +548,15 @@ namespace OpenNest.Forms
         public string Status { get; set; }
         public bool IsEditable { get; set; }
     }
+
+    internal class GroupSettings
+    {
+        public double PlateWidth { get; set; }
+        public double PlateLength { get; set; }
+        public double PartSpacing { get; set; }
+        public double EdgeLeft { get; set; }
+        public double EdgeBottom { get; set; }
+        public double EdgeRight { get; set; }
+        public double EdgeTop { get; set; }
+    }
 }

OpenNest/Forms/CadConverterForm.cs

@@ -74,9 +74,7 @@ namespace OpenNest.Forms
         {
             try
             {
-                var importer = new DxfImporter();
-                importer.SplinePrecision = Settings.Default.ImportSplinePrecision;
-                var result = importer.Import(file);
+                var result = Dxf.Import(file);
 
                 if (result.Entities.Count == 0)
                     return;
@@ -171,6 +169,7 @@ namespace OpenNest.Forms
             if (item.Entities.Any(e => e.Layer != null))
                 item.Entities.ForEach(e => e.Layer.IsVisible = true);
             ReHidePromotedEntities(item.Bends);
+            ReHideSuppressedEntities(item);
 
             filterPanel.LoadItem(item.Entities, item.Bends);
 
@@ -247,6 +246,7 @@ namespace OpenNest.Forms
 
             filterPanel.ApplyFilters(item.Entities);
             ReHidePromotedEntities(item.Bends);
+            SyncSuppressedState(item);
             entityView1.Invalidate();
             staleProgram = true;
         }
@@ -384,9 +384,7 @@ namespace OpenNest.Forms
                 newItems.Add(splitPath);
 
                 // Re-import geometry but keep bends from the split drawing
-                var importer = new DxfImporter();
-                importer.SplinePrecision = Settings.Default.ImportSplinePrecision;
-                var result = importer.Import(splitPath);
+                var result = Dxf.Import(splitPath);
 
                 var splitItem = new FileListItem
                 {
@@ -608,6 +606,61 @@ namespace OpenNest.Forms
 
         #endregion
 
+        #region Load Existing Drawings
+
+        public void LoadDrawings(IEnumerable<Drawing> drawings)
+        {
+            foreach (var drawing in drawings)
+            {
+                List<Entity> entities;
+
+                if (drawing.SourceEntities != null)
+                {
+                    // Use stored entities with stable GUIDs; apply suppression state
+                    entities = new List<Entity>(drawing.SourceEntities);
+
+                    foreach (var entity in entities)
+                        entity.IsVisible = !drawing.SuppressedEntityIds.Contains(entity.Id);
+                }
+                else
+                {
+                    // Fallback: derive entities from Program (older drawings without source entities)
+                    entities = ConvertProgram.ToGeometry(drawing.Program);
+
+                    // Re-apply source offset so entities appear in their natural position
+                    if (drawing.Source?.Offset != null && drawing.Source.Offset != Vector.Zero)
+                    {
+                        foreach (var entity in entities)
+                            entity.Offset(drawing.Source.Offset);
+                    }
+
+                    // Remove rapid traversals — they aren't part of the cut geometry
+                    entities.RemoveAll(e => e.Layer == SpecialLayers.Rapid);
+                }
+
+                var bounds = entities.GetBoundingBox();
+
+                var item = new FileListItem
+                {
+                    Name = drawing.Name,
+                    Entities = entities,
+                    Path = drawing.Source?.Path,
+                    Quantity = drawing.Quantity.Required,
+                    Customer = drawing.Customer ?? string.Empty,
+                    Bends = drawing.Bends?.ToList() ?? new List<Bend>(),
+                    SuppressedEntityIds = drawing.SuppressedEntityIds.Count > 0
+                        ? new HashSet<Guid>(drawing.SuppressedEntityIds)
+                        : null,
+                    Bounds = bounds,
+                    EntityCount = entities.Count
+                };
+
+                fileList.AddItem(item);
+            }
+        }
+
+        #endregion
+
         #region Output
 
         public List<Drawing> GetDrawings()
@@ -648,6 +701,22 @@ namespace OpenNest.Forms
                     drawing.Program = programEditor.Program;
                 else
                     drawing.Program = pgm;
+
+                // Store all entities with stable GUIDs; track suppressed by ID
+                var bendSources = new HashSet<Entity>(
+                    (item.Bends ?? new List<Bend>())
+                        .Where(b => b.SourceEntity != null)
+                        .Select(b => b.SourceEntity));
+
+                drawing.SourceEntities = item.Entities
+                    .Where(e => !bendSources.Contains(e))
+                    .ToList();
+
+                drawing.SuppressedEntityIds = new HashSet<Guid>(
+                    drawing.SourceEntities
+                        .Where(e => !(e.Layer.IsVisible && e.IsVisible))
+                        .Select(e => e.Id));
+
                 drawings.Add(drawing);
 
                 Thread.Sleep(20);
@@ -670,6 +739,47 @@ namespace OpenNest.Forms
             }
         }
 
+        private static void ReHideSuppressedEntities(FileListItem item)
+        {
+            if (item.SuppressedEntityIds == null || item.SuppressedEntityIds.Count == 0)
+                return;
+
+            foreach (var entity in item.Entities)
+            {
+                if (item.SuppressedEntityIds.Contains(entity.Id))
+                    entity.IsVisible = false;
+            }
+
+            // If all entities on a layer are suppressed, uncheck the layer too
+            var layerGroups = item.Entities
+                .Where(e => e.Layer != null)
+                .GroupBy(e => e.Layer);
+
+            foreach (var group in layerGroups)
+            {
+                if (group.All(e => !e.IsVisible))
+                    group.Key.IsVisible = false;
+            }
+        }
+
+        private static void SyncSuppressedState(FileListItem item)
+        {
+            var bendSources = new HashSet<Entity>(
+                (item.Bends ?? new List<Bend>())
+                    .Where(b => b.SourceEntity != null)
+                    .Select(b => b.SourceEntity));
+
+            var suppressed = item.Entities
+                .Where(e => !(e.Layer.IsVisible && e.IsVisible))
+                .Where(e => !bendSources.Contains(e))
+                .Select(e => e.Id);
+
+            item.SuppressedEntityIds = new HashSet<Guid>(suppressed);
+
+            if (item.SuppressedEntityIds.Count == 0)
+                item.SuppressedEntityIds = null;
+        }
+
 
         private static Color GetNextColor() => Drawing.GetNextColor();
 

OpenNest/Forms/CuttingParametersDialog.cs

@@ -0,0 +1,68 @@
+using OpenNest.CNC.CuttingStrategy;
+using OpenNest.Controls;
+using System.Drawing;
+using System.Windows.Forms;
+
+namespace OpenNest.Forms
+{
+    public class CuttingParametersDialog : Form
+    {
+        private readonly CuttingPanel cuttingPanel;
+
+        public CuttingParametersDialog()
+        {
+            Text = "Cutting Parameters";
+            Size = new Size(400, 560);
+            FormBorderStyle = FormBorderStyle.FixedDialog;
+            MaximizeBox = false;
+            MinimizeBox = false;
+            StartPosition = FormStartPosition.CenterParent;
+
+            cuttingPanel = new CuttingPanel
+            {
+                Dock = DockStyle.Fill
+            };
+
+            var buttonPanel = new Panel
+            {
+                Dock = DockStyle.Bottom,
+                Height = 40
+            };
+
+            var btnOk = new Button
+            {
+                Text = "OK",
+                DialogResult = DialogResult.OK,
+                Size = new Size(80, 28),
+                Location = new Point(220, 6)
+            };
+
+            var btnCancel = new Button
+            {
+                Text = "Cancel",
+                DialogResult = DialogResult.Cancel,
+                Size = new Size(80, 28),
+                Location = new Point(305, 6)
+            };
+
+            buttonPanel.Controls.Add(btnOk);
+            buttonPanel.Controls.Add(btnCancel);
+
+            Controls.Add(cuttingPanel);
+            Controls.Add(buttonPanel);
+
+            AcceptButton = btnOk;
+            CancelButton = btnCancel;
+        }
+
+        public void LoadParameters(CuttingParameters parameters)
+        {
+            cuttingPanel.LoadFromParameters(parameters);
+        }
+
+        public CuttingParameters GetParameters()
+        {
+            return cuttingPanel.BuildParameters();
+        }
+    }
+}

OpenNest/Forms/CuttingParametersSerializer.cs

@@ -85,7 +85,6 @@ namespace OpenNest.Forms
             {
                 LineLeadOut line => new LeadOutDto { Type = "Line", Length = line.Length, ApproachAngle = line.ApproachAngle },
                 ArcLeadOut arc => new LeadOutDto { Type = "Arc", Radius = arc.Radius },
-                MicrotabLeadOut mt => new LeadOutDto { Type = "Microtab", GapSize = mt.GapSize },
                 _ => new LeadOutDto { Type = "None" }
             };
         }
@@ -97,7 +96,6 @@ namespace OpenNest.Forms
             {
                 "Line" => new LineLeadOut { Length = dto.Length, ApproachAngle = dto.ApproachAngle },
                 "Arc" => new ArcLeadOut { Radius = dto.Radius },
-                "Microtab" => new MicrotabLeadOut { GapSize = dto.GapSize },
                 _ => new NoLeadOut()
             };
         }

OpenNest/Forms/EditNestForm.Designer.cs

@@ -47,6 +47,8 @@
             drawingListBox1 = new OpenNest.Controls.DrawingListBox();
             toolStrip2 = new System.Windows.Forms.ToolStrip();
             toolStripButton2 = new System.Windows.Forms.ToolStripButton();
+            toolStripSeparator4 = new System.Windows.Forms.ToolStripSeparator();
+            editDrawingsButton = new System.Windows.Forms.ToolStripButton();
             toolStripSeparator1 = new System.Windows.Forms.ToolStripSeparator();
             toolStripButton3 = new System.Windows.Forms.ToolStripButton();
             toolStripSeparator2 = new System.Windows.Forms.ToolStripSeparator();
@@ -175,7 +177,7 @@
             // toolStripLabel2
             // 
             toolStripLabel2.DisplayStyle = System.Windows.Forms.ToolStripItemDisplayStyle.Image;
-            toolStripLabel2.Image = Properties.Resources.delete;
+            toolStripLabel2.Image = (System.Drawing.Image)resources.GetObject("toolStripLabel2.Image");
             toolStripLabel2.Name = "toolStripLabel2";
             toolStripLabel2.Padding = new System.Windows.Forms.Padding(5, 0, 5, 0);
             toolStripLabel2.Size = new System.Drawing.Size(34, 24);
@@ -217,7 +219,7 @@
             // 
             toolStrip2.GripStyle = System.Windows.Forms.ToolStripGripStyle.Hidden;
             toolStrip2.ImageScalingSize = new System.Drawing.Size(20, 20);
-            toolStrip2.Items.AddRange(new System.Windows.Forms.ToolStripItem[] { toolStripButton2, toolStripSeparator1, toolStripButton3, toolStripSeparator2, hideNestedButton });
+            toolStrip2.Items.AddRange(new System.Windows.Forms.ToolStripItem[] { toolStripButton2, toolStripSeparator4, editDrawingsButton, toolStripSeparator1, toolStripButton3, toolStripSeparator2, hideNestedButton });
             toolStrip2.Location = new System.Drawing.Point(4, 3);
             toolStrip2.Name = "toolStrip2";
             toolStrip2.Size = new System.Drawing.Size(265, 27);
@@ -236,6 +238,21 @@
             toolStripButton2.Text = "Import Drawings";
             toolStripButton2.Click += ImportDrawings_Click;
             // 
+            // toolStripSeparator4
+            // 
+            toolStripSeparator4.Name = "toolStripSeparator4";
+            toolStripSeparator4.Size = new System.Drawing.Size(6, 27);
+            // 
+            // editDrawingsButton
+            // 
+            editDrawingsButton.DisplayStyle = System.Windows.Forms.ToolStripItemDisplayStyle.Image;
+            editDrawingsButton.Image = (System.Drawing.Image)resources.GetObject("editDrawingsButton.Image");
+            editDrawingsButton.Name = "editDrawingsButton";
+            editDrawingsButton.Padding = new System.Windows.Forms.Padding(5, 0, 5, 0);
+            editDrawingsButton.Size = new System.Drawing.Size(34, 24);
+            editDrawingsButton.Text = "Edit Drawings in Converter";
+            editDrawingsButton.Click += EditDrawingsInConverter_Click;
+            // 
             // toolStripSeparator1
             // 
             toolStripSeparator1.Name = "toolStripSeparator1";
@@ -312,6 +329,8 @@
         private System.Windows.Forms.ColumnHeader utilColumn;
         private System.Windows.Forms.ToolStrip toolStrip2;
         private System.Windows.Forms.ToolStripButton toolStripButton2;
+        private System.Windows.Forms.ToolStripSeparator toolStripSeparator4;
+        private System.Windows.Forms.ToolStripButton editDrawingsButton;
         private System.Windows.Forms.ToolStripSeparator toolStripSeparator1;
         private System.Windows.Forms.ToolStripButton toolStripButton3;
         private System.Windows.Forms.ToolStripSeparator toolStripSeparator2;

OpenNest/Forms/EditNestForm.cs

@@ -52,6 +52,7 @@ namespace OpenNest.Forms
         private EditNestForm()
         {
             PlateView = new PlateView();
+            PlateView.MouseEnter += PlateView_MouseEnter;
             PlateView.Enter += PlateView_Enter;
             PlateView.PartAdded += PlateView_PartAdded;
             PlateView.PartRemoved += PlateView_PartRemoved;
@@ -259,6 +260,11 @@ namespace OpenNest.Forms
 
         public void UpdateDrawingList()
         {
+            var topIndex = drawingListBox1.TopIndex;
+            var selected = drawingListBox1.SelectedItem;
+
+            drawingListBox1.BeginUpdate();
+
             drawingListBox1.Items.Clear();
 
             foreach (var dwg in Nest.Drawings.OrderBy(d => d.Name).ToList())
@@ -268,6 +274,14 @@ namespace OpenNest.Forms
 
                 drawingListBox1.Items.Add(dwg);
             }
+
+            if (selected != null && drawingListBox1.Items.Contains(selected))
+                drawingListBox1.SelectedItem = selected;
+
+            if (topIndex < drawingListBox1.Items.Count)
+                drawingListBox1.TopIndex = topIndex;
+
+            drawingListBox1.EndUpdate();
         }
 
         public void Save()
@@ -349,9 +363,8 @@ namespace OpenNest.Forms
             {
                 if (dlg.FilterIndex == 1)
                 {
-                    var exporter = new DxfExporter();
-                    var success = exporter.ExportPlate(PlateView.Plate, dlg.FileName);
-                    return success;
+                    Dxf.ExportPlate(PlateView.Plate, dlg.FileName);
+                    return true;
                 }
                 else if (dlg.FilterIndex == 2)
                 {
@@ -527,8 +540,7 @@ namespace OpenNest.Forms
             var plate = PlateView.Plate;
             var name = string.Format("{0}-P{1}.dxf", Nest.Name, PlateManager.CurrentIndex + 1);
             var path = Path.Combine(Path.GetTempPath(), name);
-            var exporter = new DxfExporter();
-            exporter.ExportPlate(plate, path);
+            Dxf.ExportPlate(plate, path);
 
             Process.Start(path);
         }
@@ -707,19 +719,17 @@ namespace OpenNest.Forms
 
             var plate = PlateView.Plate;
 
-            if (plate.CuttingParameters == null)
-            {
-                var json = Properties.Settings.Default.CuttingParametersJson;
-                if (!string.IsNullOrEmpty(json))
-                {
-                    try { plate.CuttingParameters = CuttingParametersSerializer.Deserialize(json); }
-                    catch { plate.CuttingParameters = new CuttingParameters(); }
-                }
-                else
-                {
-                    plate.CuttingParameters = new CuttingParameters();
-                }
-            }
+            var parameters = LoadOrDefaultParameters(plate.CuttingParameters);
+
+            using var dlg = new CuttingParametersDialog();
+            dlg.LoadParameters(parameters);
+
+            if (dlg.ShowDialog() != DialogResult.OK)
+                return;
+
+            parameters = dlg.GetParameters();
+            plate.CuttingParameters = parameters;
+            SaveCuttingParameters(parameters);
 
             var assigner = new LeadInAssigner
             {
@@ -770,17 +780,16 @@ namespace OpenNest.Forms
             if (Nest == null)
                 return;
 
-            CuttingParameters parameters;
-            var json = Properties.Settings.Default.CuttingParametersJson;
-            if (!string.IsNullOrEmpty(json))
-            {
-                try { parameters = CuttingParametersSerializer.Deserialize(json); }
-                catch { parameters = new CuttingParameters(); }
-            }
-            else
-            {
-                parameters = new CuttingParameters();
-            }
+            var parameters = LoadOrDefaultParameters(PlateView?.Plate?.CuttingParameters);
+
+            using var dlg = new CuttingParametersDialog();
+            dlg.LoadParameters(parameters);
+
+            if (dlg.ShowDialog() != DialogResult.OK)
+                return;
+
+            parameters = dlg.GetParameters();
+            SaveCuttingParameters(parameters);
 
             var assigner = new LeadInAssigner
             {
@@ -828,29 +837,88 @@ namespace OpenNest.Forms
 
             var plate = PlateView.Plate;
 
-            // If no cutting parameters exist, initialize from saved settings or defaults
             if (plate.CuttingParameters == null)
-            {
-                var json = Properties.Settings.Default.CuttingParametersJson;
-                if (!string.IsNullOrEmpty(json))
-                {
-                    try { plate.CuttingParameters = CuttingParametersSerializer.Deserialize(json); }
-                    catch { plate.CuttingParameters = new CuttingParameters(); }
-                }
-                else
-                {
-                    plate.CuttingParameters = new CuttingParameters();
-                }
-            }
+                plate.CuttingParameters = LoadOrDefaultParameters(null);
 
             PlateView.SetAction(typeof(Actions.ActionLeadIn));
         }
 
+        private static CuttingParameters LoadOrDefaultParameters(CuttingParameters existing)
+        {
+            if (existing != null)
+                return existing;
+
+            var json = Properties.Settings.Default.CuttingParametersJson;
+            if (!string.IsNullOrEmpty(json))
+            {
+                try { return CuttingParametersSerializer.Deserialize(json); }
+                catch { /* fall through */ }
+            }
+
+            return new CuttingParameters();
+        }
+
+        private static void SaveCuttingParameters(CuttingParameters parameters)
+        {
+            var json = CuttingParametersSerializer.Serialize(parameters);
+            Properties.Settings.Default.CuttingParametersJson = json;
+            Properties.Settings.Default.Save();
+        }
+
         private void ImportDrawings_Click(object sender, EventArgs e)
         {
             Import();
         }
 
+        private void EditDrawingsInConverter_Click(object sender, EventArgs e)
+        {
+            if (Nest.Drawings.Count == 0)
+                return;
+
+            var converter = new CadConverterForm();
+            converter.LoadDrawings(Nest.Drawings);
+
+            if (converter.ShowDialog() != DialogResult.OK)
+                return;
+
+            var newDrawings = converter.GetDrawings();
+            var newByName = newDrawings.ToDictionary(d => d.Name);
+
+            // Update existing drawings in-place so parts keep their BaseDrawing references
+            foreach (var existing in Nest.Drawings.ToList())
+            {
+                if (newByName.TryGetValue(existing.Name, out var updated))
+                {
+                    existing.Program = updated.Program;
+                    existing.SourceEntities = updated.SourceEntities;
+                    existing.SuppressedEntityIds = updated.SuppressedEntityIds;
+                    existing.Source = updated.Source;
+                    existing.Customer = updated.Customer;
+                    existing.Quantity.Required = updated.Quantity.Required;
+                    existing.Bends.Clear();
+                    existing.Bends.AddRange(updated.Bends);
+                    newByName.Remove(existing.Name);
+                }
+                else
+                {
+                    Nest.Drawings.Remove(existing);
+                }
+            }
+
+            // Add any new drawings that weren't in the original set
+            foreach (var d in newByName.Values)
+                Nest.Drawings.Add(d);
+
+            // Refresh all parts to use the updated programs
+            foreach (var plate in Nest.Plates)
+                foreach (var part in plate.Parts)
+                    if (!part.BaseDrawing.IsCutOff)
+                        part.Update();
+
+            UpdateDrawingList();
+            PlateView.Invalidate();
+        }
+
         private void CleanUnusedDrawings_Click(object sender, EventArgs e)
         {
             var result = MessageBox.Show(
@@ -881,12 +949,12 @@ namespace OpenNest.Forms
             PlateView.Plate = PlateManager.CurrentPlate;
             PlateView.ZoomToFit();
             UpdatePlateHeader();
+            UpdateRemovePlateButton();
             PlateChanged?.Invoke(this, EventArgs.Empty);
         }
 
         private void PlateManager_PlateListChanged(object sender, EventArgs e)
         {
-            tabControl1.SelectedIndex = 0;
             UpdatePlateList();
             UpdatePlateHeader();
             UpdateRemovePlateButton();
@@ -935,9 +1003,29 @@ namespace OpenNest.Forms
             drawingListBox1.Invoke(new MethodInvoker(() =>
             {
                 if (hideNestedButton.Checked)
-                    UpdateDrawingList();
-                else
-                    drawingListBox1.Refresh();
+                {
+                    drawingListBox1.BeginUpdate();
+
+                    for (var i = drawingListBox1.Items.Count - 1; i >= 0; i--)
+                    {
+                        var dwg = (Drawing)drawingListBox1.Items[i];
+                        if (dwg.Quantity.Required > 0 && dwg.Quantity.Remaining == 0)
+                            drawingListBox1.Items.RemoveAt(i);
+                    }
+
+                    foreach (var dwg in Nest.Drawings.OrderBy(d => d.Name))
+                    {
+                        if (dwg.Quantity.Required > 0 && dwg.Quantity.Remaining == 0)
+                            continue;
+
+                        if (!drawingListBox1.Items.Contains(dwg))
+                            drawingListBox1.Items.Add(dwg);
+                    }
+
+                    drawingListBox1.EndUpdate();
+                }
+
+                drawingListBox1.Invalidate();
             }));
         }
 
@@ -995,6 +1083,12 @@ namespace OpenNest.Forms
             addPart = true;
         }
 
+        private void PlateView_MouseEnter(object sender, EventArgs e)
+        {
+            if (!PlateView.Focused)
+                PlateView.Focus();
+        }
+
         private void PlateView_Enter(object sender, EventArgs e)
         {
             if (!addPart)

OpenNest/Forms/MainForm.Designer.cs

@@ -85,6 +85,7 @@
             mnuNest = new System.Windows.Forms.ToolStripMenuItem();
             mnuNestEdit = new System.Windows.Forms.ToolStripMenuItem();
             mnuNestImportDrawing = new System.Windows.Forms.ToolStripMenuItem();
+            mnuNestShapeLibrary = new System.Windows.Forms.ToolStripMenuItem();
             toolStripMenuItem7 = new System.Windows.Forms.ToolStripSeparator();
             mnuNestFirstPlate = new System.Windows.Forms.ToolStripMenuItem();
             mnuNestLastPlate = new System.Windows.Forms.ToolStripMenuItem();
@@ -559,7 +560,7 @@
             // 
             // mnuNest
             // 
-            mnuNest.DropDownItems.AddRange(new System.Windows.Forms.ToolStripItem[] { mnuNestEdit, mnuNestImportDrawing, toolStripMenuItem7, mnuNestFirstPlate, mnuNestLastPlate, toolStripMenuItem6, mnuNestNextPlate, mnuNestPreviousPlate, toolStripMenuItem12, runAutoNestToolStripMenuItem, autoSequenceAllPlatesToolStripMenuItem, mnuNestRemoveEmptyPlates, mnuNestPost, toolStripMenuItem19, calculateCutTimeToolStripMenuItem, toolStripMenuItem22, mnuNestAssignLeadIns, mnuNestRemoveLeadIns });
+            mnuNest.DropDownItems.AddRange(new System.Windows.Forms.ToolStripItem[] { mnuNestEdit, mnuNestImportDrawing, mnuNestShapeLibrary, toolStripMenuItem7, mnuNestFirstPlate, mnuNestLastPlate, toolStripMenuItem6, mnuNestNextPlate, mnuNestPreviousPlate, toolStripMenuItem12, runAutoNestToolStripMenuItem, autoSequenceAllPlatesToolStripMenuItem, mnuNestRemoveEmptyPlates, mnuNestPost, toolStripMenuItem19, calculateCutTimeToolStripMenuItem, toolStripMenuItem22, mnuNestAssignLeadIns, mnuNestRemoveLeadIns });
             mnuNest.Name = "mnuNest";
             mnuNest.Size = new System.Drawing.Size(43, 20);
             mnuNest.Text = "&Nest";
@@ -579,6 +580,13 @@
             mnuNestImportDrawing.Text = "Import Drawing";
             mnuNestImportDrawing.Click += Import_Click;
             //
+            // mnuNestShapeLibrary
+            //
+            mnuNestShapeLibrary.Name = "mnuNestShapeLibrary";
+            mnuNestShapeLibrary.Size = new System.Drawing.Size(205, 22);
+            mnuNestShapeLibrary.Text = "Shape Library";
+            mnuNestShapeLibrary.Click += ShapeLibrary_Click;
+            //
             // toolStripMenuItem7
             // 
             toolStripMenuItem7.Name = "toolStripMenuItem7";
@@ -1213,6 +1221,7 @@
         private System.Windows.Forms.ToolStripMenuItem mnuNest;
         private System.Windows.Forms.ToolStripMenuItem mnuNestEdit;
         private System.Windows.Forms.ToolStripMenuItem mnuNestImportDrawing;
+        private System.Windows.Forms.ToolStripMenuItem mnuNestShapeLibrary;
         private System.Windows.Forms.ToolStripSeparator toolStripMenuItem7;
         private System.Windows.Forms.ToolStripMenuItem mnuNestFirstPlate;
         private System.Windows.Forms.ToolStripMenuItem mnuNestLastPlate;

OpenNest/Forms/MainForm.cs

@@ -64,8 +64,8 @@ namespace OpenNest.Forms
             //if (GpuEvaluatorFactory.GpuAvailable)
             //    BestFitCache.CreateEvaluator = (drawing, spacing) => GpuEvaluatorFactory.Create(drawing, spacing);
 
-            if (GpuEvaluatorFactory.GpuAvailable)
-                BestFitCache.CreateSlideComputer = () => GpuEvaluatorFactory.CreateSlideComputer();
+            //if (GpuEvaluatorFactory.GpuAvailable)
+            //    BestFitCache.CreateSlideComputer = () => GpuEvaluatorFactory.CreateSlideComputer();
 
             var enginesDir = Path.Combine(Application.StartupPath, "Engines");
             NestEngineRegistry.LoadPlugins(enginesDir);
@@ -829,6 +829,20 @@ namespace OpenNest.Forms
             activeForm.Import();
         }
 
+        private void ShapeLibrary_Click(object sender, EventArgs e)
+        {
+            if (activeForm == null) return;
+
+            var form = new ShapeLibraryForm();
+            form.ShowDialog();
+
+            var drawings = form.GetDrawings();
+            if (drawings.Count == 0) return;
+
+            drawings.ForEach(d => activeForm.Nest.Drawings.Add(d));
+            activeForm.UpdateDrawingList();
+        }
+
         private void EditNest_Click(object sender, EventArgs e)
         {
             if (activeForm == null) return;
@@ -932,6 +946,10 @@ namespace OpenNest.Forms
             var optimizePlateSize = form.OptimizePlateSize;
             var plateOptions = optimizePlateSize ? form.GetPlateOptions() : null;
             var salvageRate = form.SalvageRate;
+            var partFirstMode = form.PartFirstMode;
+            var sortOrder = form.SortOrder;
+            var minRemnantSize = form.MinRemnantSize;
+            var allowPlateCreation = form.AllowPlateCreation;
 
             if (optimizePlateSize)
             {
@@ -960,7 +978,7 @@ namespace OpenNest.Forms
             try
             {
                 await RunAutoNestAsync(items, progressForm, progress, nestingCts.Token,
-                    plateOptions, salvageRate);
+                    plateOptions, salvageRate, partFirstMode, sortOrder, minRemnantSize, allowPlateCreation);
             }
             catch (Exception ex)
             {
@@ -984,8 +1002,52 @@ namespace OpenNest.Forms
             IProgress<NestProgress> progress,
             CancellationToken token,
             List<PlateOption> plateOptions = null,
-            double salvageRate = 0.5)
+            double salvageRate = 0.5,
+            bool partFirstMode = false,
+            PartSortOrder sortOrder = PartSortOrder.BoundingBoxArea,
+            double minRemnantSize = 12.0,
+            bool allowPlateCreation = true)
         {
+            if (partFirstMode)
+            {
+                var existingPlates = new List<Plate>();
+                for (var i = 0; i < activeForm.Nest.Plates.Count; i++)
+                {
+                    var p = activeForm.Nest.Plates[i];
+                    if (p.Parts.Count > 0)
+                        existingPlates.Add(p);
+                }
+
+                var template = activeForm.PlateView.Plate;
+
+                var nestOptions = new MultiPlateNestOptions
+                {
+                    Template = template,
+                    PlateOptions = plateOptions,
+                    SalvageRate = salvageRate,
+                    SortOrder = sortOrder,
+                    MinRemnantSize = minRemnantSize,
+                    AllowPlateCreation = allowPlateCreation,
+                };
+
+                var result = await Task.Run(() =>
+                    MultiPlateNester.Nest(items, nestOptions, existingPlates, progress, token));
+
+                foreach (var pr in result.Plates)
+                {
+                    if (pr.IsNew)
+                    {
+                        var plate = GetOrCreatePlate(progressForm);
+                        plate.Size = pr.Plate.Size;
+                        plate.Parts.AddRange(pr.Parts);
+                    }
+                }
+
+                activeForm.Nest.UpdateDrawingQuantities();
+                progressForm.ShowCompleted();
+                return;
+            }
+
             const int maxPlates = 100;
 
             for (var plateIndex = 0; plateIndex < maxPlates; plateIndex++)

OpenNest/Forms/NestProgressForm.Designer.cs

@@ -427,7 +427,7 @@ namespace OpenNest.Forms
             plate1.Quantity = 0;
             previewPlateView.Plate = plate1;
             previewPlateView.RotateIncrementAngle = 10D;
-            previewPlateView.SelectedCutOff = null;
+
             previewPlateView.ShowBendLines = false;
             previewPlateView.Size = new System.Drawing.Size(356, 341);
             previewPlateView.Status = "Select";

OpenNest/Forms/OptionsForm.Designer.cs

@@ -33,11 +33,9 @@
             this.label1 = new System.Windows.Forms.Label();
             this.toolTip1 = new System.Windows.Forms.ToolTip(this.components);
             this.numericUpDown1 = new OpenNest.Controls.NumericUpDown();
-            this.label2 = new System.Windows.Forms.Label();
             this.tableLayoutPanel1 = new System.Windows.Forms.TableLayoutPanel();
             this.textBox1 = new System.Windows.Forms.TextBox();
             this.label3 = new System.Windows.Forms.Label();
-            this.numericUpDown2 = new OpenNest.Controls.NumericUpDown();
             this.button1 = new System.Windows.Forms.Button();
             this.saveButton = new System.Windows.Forms.Button();
             this.cancelButton = new System.Windows.Forms.Button();
@@ -46,7 +44,6 @@
             this.strategyGroupBox = new System.Windows.Forms.GroupBox();
             ((System.ComponentModel.ISupportInitialize)(this.numericUpDown1)).BeginInit();
             this.tableLayoutPanel1.SuspendLayout();
-            ((System.ComponentModel.ISupportInitialize)(this.numericUpDown2)).BeginInit();
             this.bottomPanel1.SuspendLayout();
             this.SuspendLayout();
             // 
@@ -88,16 +85,6 @@
             this.numericUpDown1.TabIndex = 4;
             this.toolTip1.SetToolTip(this.numericUpDown1, "The amount to round the plate size up.");
             //
-            // label2
-            // 
-            this.label2.Anchor = ((System.Windows.Forms.AnchorStyles)((System.Windows.Forms.AnchorStyles.Left | System.Windows.Forms.AnchorStyles.Right)));
-            this.label2.AutoSize = true;
-            this.label2.Location = new System.Drawing.Point(3, 92);
-            this.label2.Name = "label2";
-            this.label2.Size = new System.Drawing.Size(145, 16);
-            this.label2.TabIndex = 5;
-            this.label2.Text = "Import spline precision:\r\n";
-            // 
             // tableLayoutPanel1
             // 
             this.tableLayoutPanel1.ColumnCount = 4;
@@ -107,19 +94,16 @@
             this.tableLayoutPanel1.ColumnStyles.Add(new System.Windows.Forms.ColumnStyle(System.Windows.Forms.SizeType.Absolute, 100F));
             this.tableLayoutPanel1.Controls.Add(this.label1, 0, 1);
             this.tableLayoutPanel1.Controls.Add(this.textBox1, 1, 0);
-            this.tableLayoutPanel1.Controls.Add(this.label2, 0, 2);
             this.tableLayoutPanel1.Controls.Add(this.label3, 0, 0);
-            this.tableLayoutPanel1.Controls.Add(this.checkBox1, 0, 3);
-            this.tableLayoutPanel1.Controls.Add(this.numericUpDown2, 1, 2);
+            this.tableLayoutPanel1.Controls.Add(this.checkBox1, 0, 2);
             this.tableLayoutPanel1.Controls.Add(this.numericUpDown1, 1, 1);
             this.tableLayoutPanel1.Controls.Add(this.button1, 3, 0);
             this.tableLayoutPanel1.Location = new System.Drawing.Point(12, 12);
             this.tableLayoutPanel1.Name = "tableLayoutPanel1";
-            this.tableLayoutPanel1.RowCount = 4;
-            this.tableLayoutPanel1.RowStyles.Add(new System.Windows.Forms.RowStyle(System.Windows.Forms.SizeType.Percent, 25F));
-            this.tableLayoutPanel1.RowStyles.Add(new System.Windows.Forms.RowStyle(System.Windows.Forms.SizeType.Percent, 25F));
-            this.tableLayoutPanel1.RowStyles.Add(new System.Windows.Forms.RowStyle(System.Windows.Forms.SizeType.Percent, 25F));
-            this.tableLayoutPanel1.RowStyles.Add(new System.Windows.Forms.RowStyle(System.Windows.Forms.SizeType.Percent, 25F));
+            this.tableLayoutPanel1.RowCount = 3;
+            this.tableLayoutPanel1.RowStyles.Add(new System.Windows.Forms.RowStyle(System.Windows.Forms.SizeType.Percent, 33.33F));
+            this.tableLayoutPanel1.RowStyles.Add(new System.Windows.Forms.RowStyle(System.Windows.Forms.SizeType.Percent, 33.33F));
+            this.tableLayoutPanel1.RowStyles.Add(new System.Windows.Forms.RowStyle(System.Windows.Forms.SizeType.Percent, 33.34F));
             this.tableLayoutPanel1.Size = new System.Drawing.Size(684, 160);
             this.tableLayoutPanel1.TabIndex = 0;
             // 
@@ -142,30 +126,6 @@
             this.label3.TabIndex = 0;
             this.label3.Text = "Nest Template Path:";
             //
-            // numericUpDown2
-            // 
-            this.numericUpDown2.Anchor = ((System.Windows.Forms.AnchorStyles)((System.Windows.Forms.AnchorStyles.Left | System.Windows.Forms.AnchorStyles.Right)));
-            this.numericUpDown2.Location = new System.Drawing.Point(154, 89);
-            this.numericUpDown2.Maximum = new decimal(new int[] {
-            360,
-            0,
-            0,
-            0});
-            this.numericUpDown2.Minimum = new decimal(new int[] {
-            3,
-            0,
-            0,
-            0});
-            this.numericUpDown2.Name = "numericUpDown2";
-            this.numericUpDown2.Size = new System.Drawing.Size(130, 22);
-            this.numericUpDown2.Suffix = "";
-            this.numericUpDown2.TabIndex = 6;
-            this.numericUpDown2.Value = new decimal(new int[] {
-            200,
-            0,
-            0,
-            0});
-            // 
             // button1
             // 
             this.button1.Anchor = ((System.Windows.Forms.AnchorStyles)((System.Windows.Forms.AnchorStyles.Left | System.Windows.Forms.AnchorStyles.Right)));
@@ -259,7 +219,6 @@
             ((System.ComponentModel.ISupportInitialize)(this.numericUpDown1)).EndInit();
             this.tableLayoutPanel1.ResumeLayout(false);
             this.tableLayoutPanel1.PerformLayout();
-            ((System.ComponentModel.ISupportInitialize)(this.numericUpDown2)).EndInit();
             this.bottomPanel1.ResumeLayout(false);
             this.ResumeLayout(false);
 
@@ -273,8 +232,6 @@
         private System.Windows.Forms.Label label1;
         private Controls.NumericUpDown numericUpDown1;
         private System.Windows.Forms.ToolTip toolTip1;
-        private System.Windows.Forms.Label label2;
-        private Controls.NumericUpDown numericUpDown2;
         private Controls.BottomPanel bottomPanel1;
         private System.Windows.Forms.TableLayoutPanel tableLayoutPanel1;
         private System.Windows.Forms.TextBox textBox1;

OpenNest/Forms/OptionsForm.cs

@@ -67,7 +67,6 @@ namespace OpenNest.Forms
             textBox1.Text = Settings.Default.NestTemplatePath;
             checkBox1.Checked = Settings.Default.CreateNewNestOnOpen;
             numericUpDown1.Value = (decimal)Settings.Default.AutoSizePlateFactor;
-            numericUpDown2.Value = (decimal)Settings.Default.ImportSplinePrecision;
 
             var disabledNames = ParseDisabledStrategies(Settings.Default.DisabledStrategies);
             foreach (DataGridViewRow row in strategyGrid.Rows)
@@ -79,7 +78,6 @@ namespace OpenNest.Forms
             Settings.Default.NestTemplatePath = textBox1.Text;
             Settings.Default.CreateNewNestOnOpen = checkBox1.Checked;
             Settings.Default.AutoSizePlateFactor = (double)numericUpDown1.Value;
-            Settings.Default.ImportSplinePrecision = (int)numericUpDown2.Value;
 
             var disabledNames = new List<string>();
             foreach (DataGridViewRow row in strategyGrid.Rows)

OpenNest/Forms/ShapeLibraryForm.Designer.cs

@@ -0,0 +1,338 @@
+namespace OpenNest.Forms
+{
+    partial class ShapeLibraryForm
+    {
+        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()
+        {
+            ColorScheme colorScheme1 = new ColorScheme();
+            CutOffSettings cutOffSettings1 = new CutOffSettings();
+            Plate plate1 = new Plate();
+            Collections.ObservableList<CutOff> observableList_11 = new Collections.ObservableList<CutOff>();
+            Collections.ObservableList<Part> observableList_12 = new Collections.ObservableList<Part>();
+            splitContainer = new System.Windows.Forms.SplitContainer();
+            shapeListBox = new System.Windows.Forms.ListBox();
+            layoutTable = new System.Windows.Forms.TableLayoutPanel();
+            fieldsTable = new System.Windows.Forms.TableLayoutPanel();
+            nameLabel = new System.Windows.Forms.Label();
+            nameTextBox = new System.Windows.Forms.TextBox();
+            qtyLabel = new System.Windows.Forms.Label();
+            quantityUpDown = new OpenNest.Controls.NumericUpDown();
+            configLabel = new System.Windows.Forms.Label();
+            configComboBox = new System.Windows.Forms.ComboBox();
+            contentPanel = new System.Windows.Forms.Panel();
+            previewBox = new OpenNest.Controls.ShapePreviewControl();
+            parametersPanel = new System.Windows.Forms.Panel();
+            buttonPanel = new System.Windows.Forms.Panel();
+            addButton = new System.Windows.Forms.Button();
+            closeButton = new System.Windows.Forms.Button();
+            ((System.ComponentModel.ISupportInitialize)splitContainer).BeginInit();
+            splitContainer.Panel1.SuspendLayout();
+            splitContainer.Panel2.SuspendLayout();
+            splitContainer.SuspendLayout();
+            layoutTable.SuspendLayout();
+            fieldsTable.SuspendLayout();
+            ((System.ComponentModel.ISupportInitialize)quantityUpDown).BeginInit();
+            contentPanel.SuspendLayout();
+            buttonPanel.SuspendLayout();
+            SuspendLayout();
+            // 
+            // splitContainer
+            // 
+            splitContainer.Dock = System.Windows.Forms.DockStyle.Fill;
+            splitContainer.FixedPanel = System.Windows.Forms.FixedPanel.Panel1;
+            splitContainer.Location = new System.Drawing.Point(0, 0);
+            splitContainer.Name = "splitContainer";
+            // 
+            // splitContainer.Panel1
+            // 
+            splitContainer.Panel1.Controls.Add(shapeListBox);
+            // 
+            // splitContainer.Panel2
+            // 
+            splitContainer.Panel2.Controls.Add(layoutTable);
+            splitContainer.Size = new System.Drawing.Size(750, 520);
+            splitContainer.SplitterDistance = 150;
+            splitContainer.TabIndex = 0;
+            // 
+            // shapeListBox
+            // 
+            shapeListBox.BorderStyle = System.Windows.Forms.BorderStyle.None;
+            shapeListBox.Dock = System.Windows.Forms.DockStyle.Fill;
+            shapeListBox.DrawMode = System.Windows.Forms.DrawMode.OwnerDrawFixed;
+            shapeListBox.Font = new System.Drawing.Font("Segoe UI", 10F);
+            shapeListBox.IntegralHeight = false;
+            shapeListBox.ItemHeight = 32;
+            shapeListBox.Location = new System.Drawing.Point(0, 0);
+            shapeListBox.Name = "shapeListBox";
+            shapeListBox.Size = new System.Drawing.Size(150, 520);
+            shapeListBox.TabIndex = 0;
+            // 
+            // layoutTable
+            // 
+            layoutTable.ColumnCount = 1;
+            layoutTable.ColumnStyles.Add(new System.Windows.Forms.ColumnStyle(System.Windows.Forms.SizeType.Percent, 100F));
+            layoutTable.Controls.Add(fieldsTable, 0, 0);
+            layoutTable.Controls.Add(contentPanel, 0, 1);
+            layoutTable.Controls.Add(buttonPanel, 0, 2);
+            layoutTable.Dock = System.Windows.Forms.DockStyle.Fill;
+            layoutTable.Location = new System.Drawing.Point(0, 0);
+            layoutTable.Name = "layoutTable";
+            layoutTable.Padding = new System.Windows.Forms.Padding(6, 4, 6, 0);
+            layoutTable.RowCount = 3;
+            layoutTable.RowStyles.Add(new System.Windows.Forms.RowStyle());
+            layoutTable.RowStyles.Add(new System.Windows.Forms.RowStyle(System.Windows.Forms.SizeType.Percent, 100F));
+            layoutTable.RowStyles.Add(new System.Windows.Forms.RowStyle(System.Windows.Forms.SizeType.Absolute, 44F));
+            layoutTable.Size = new System.Drawing.Size(596, 520);
+            layoutTable.TabIndex = 0;
+            // 
+            // fieldsTable
+            // 
+            fieldsTable.AutoSize = true;
+            fieldsTable.ColumnCount = 2;
+            fieldsTable.ColumnStyles.Add(new System.Windows.Forms.ColumnStyle());
+            fieldsTable.ColumnStyles.Add(new System.Windows.Forms.ColumnStyle(System.Windows.Forms.SizeType.Percent, 100F));
+            fieldsTable.Controls.Add(nameLabel, 0, 0);
+            fieldsTable.Controls.Add(nameTextBox, 1, 0);
+            fieldsTable.Controls.Add(qtyLabel, 0, 1);
+            fieldsTable.Controls.Add(quantityUpDown, 1, 1);
+            fieldsTable.Controls.Add(configLabel, 0, 2);
+            fieldsTable.Controls.Add(configComboBox, 1, 2);
+            fieldsTable.Dock = System.Windows.Forms.DockStyle.Fill;
+            fieldsTable.Location = new System.Drawing.Point(6, 4);
+            fieldsTable.Margin = new System.Windows.Forms.Padding(0, 0, 0, 4);
+            fieldsTable.Name = "fieldsTable";
+            fieldsTable.RowCount = 3;
+            fieldsTable.RowStyles.Add(new System.Windows.Forms.RowStyle());
+            fieldsTable.RowStyles.Add(new System.Windows.Forms.RowStyle());
+            fieldsTable.RowStyles.Add(new System.Windows.Forms.RowStyle());
+            fieldsTable.Size = new System.Drawing.Size(584, 99);
+            fieldsTable.TabIndex = 0;
+            // 
+            // nameLabel
+            // 
+            nameLabel.Anchor = System.Windows.Forms.AnchorStyles.Left;
+            nameLabel.AutoSize = true;
+            nameLabel.Location = new System.Drawing.Point(4, 8);
+            nameLabel.Margin = new System.Windows.Forms.Padding(4, 4, 8, 4);
+            nameLabel.Name = "nameLabel";
+            nameLabel.Size = new System.Drawing.Size(46, 17);
+            nameLabel.TabIndex = 0;
+            nameLabel.Text = "Name:";
+            // 
+            // nameTextBox
+            // 
+            nameTextBox.Anchor = System.Windows.Forms.AnchorStyles.Left | System.Windows.Forms.AnchorStyles.Right;
+            nameTextBox.Location = new System.Drawing.Point(106, 4);
+            nameTextBox.Margin = new System.Windows.Forms.Padding(4);
+            nameTextBox.Name = "nameTextBox";
+            nameTextBox.Size = new System.Drawing.Size(474, 25);
+            nameTextBox.TabIndex = 1;
+            // 
+            // qtyLabel
+            // 
+            qtyLabel.Anchor = System.Windows.Forms.AnchorStyles.Left;
+            qtyLabel.AutoSize = true;
+            qtyLabel.Location = new System.Drawing.Point(4, 41);
+            qtyLabel.Margin = new System.Windows.Forms.Padding(4, 4, 8, 4);
+            qtyLabel.Name = "qtyLabel";
+            qtyLabel.Size = new System.Drawing.Size(59, 17);
+            qtyLabel.TabIndex = 2;
+            qtyLabel.Text = "Quantity:";
+            // 
+            // quantityUpDown
+            // 
+            quantityUpDown.Location = new System.Drawing.Point(106, 37);
+            quantityUpDown.Margin = new System.Windows.Forms.Padding(4);
+            quantityUpDown.Maximum = new decimal(new int[] { 999999, 0, 0, 0 });
+            quantityUpDown.Minimum = new decimal(new int[] { 1, 0, 0, 0 });
+            quantityUpDown.Name = "quantityUpDown";
+            quantityUpDown.Size = new System.Drawing.Size(100, 25);
+            quantityUpDown.Suffix = "";
+            quantityUpDown.TabIndex = 2;
+            quantityUpDown.Value = new decimal(new int[] { 1, 0, 0, 0 });
+            // 
+            // configLabel
+            // 
+            configLabel.Anchor = System.Windows.Forms.AnchorStyles.Left;
+            configLabel.AutoSize = true;
+            configLabel.Location = new System.Drawing.Point(4, 74);
+            configLabel.Margin = new System.Windows.Forms.Padding(4, 4, 8, 4);
+            configLabel.Name = "configLabel";
+            configLabel.Size = new System.Drawing.Size(90, 17);
+            configLabel.TabIndex = 3;
+            configLabel.Text = "Configuration:";
+            configLabel.Visible = false;
+            // 
+            // configComboBox
+            // 
+            configComboBox.Anchor = System.Windows.Forms.AnchorStyles.Left | System.Windows.Forms.AnchorStyles.Right;
+            configComboBox.DropDownStyle = System.Windows.Forms.ComboBoxStyle.DropDownList;
+            configComboBox.Location = new System.Drawing.Point(106, 70);
+            configComboBox.Margin = new System.Windows.Forms.Padding(4);
+            configComboBox.Name = "configComboBox";
+            configComboBox.Size = new System.Drawing.Size(474, 25);
+            configComboBox.TabIndex = 3;
+            configComboBox.Visible = false;
+            // 
+            // contentPanel
+            // 
+            contentPanel.Controls.Add(previewBox);
+            contentPanel.Controls.Add(parametersPanel);
+            contentPanel.Dock = System.Windows.Forms.DockStyle.Fill;
+            contentPanel.Location = new System.Drawing.Point(9, 110);
+            contentPanel.Name = "contentPanel";
+            contentPanel.Size = new System.Drawing.Size(578, 363);
+            contentPanel.TabIndex = 1;
+            // 
+            // previewBox
+            // 
+            previewBox.ActiveWorkArea = null;
+            previewBox.AllowPan = false;
+            previewBox.AllowSelect = false;
+            previewBox.AllowZoom = false;
+            previewBox.BackColor = System.Drawing.Color.White;
+            colorScheme1.BackgroundColor = System.Drawing.Color.DarkGray;
+            colorScheme1.BoundingBoxColor = System.Drawing.Color.FromArgb(128, 128, 255);
+            colorScheme1.EdgeSpacingColor = System.Drawing.Color.FromArgb(180, 180, 180);
+            colorScheme1.LayoutFillColor = System.Drawing.Color.WhiteSmoke;
+            colorScheme1.LayoutOutlineColor = System.Drawing.Color.Gray;
+            colorScheme1.OriginColor = System.Drawing.Color.Gray;
+            colorScheme1.PreviewPartColor = System.Drawing.Color.FromArgb(255, 140, 0);
+            colorScheme1.RapidColor = System.Drawing.Color.DodgerBlue;
+            previewBox.ColorScheme = colorScheme1;
+            cutOffSettings1.CutDirection = CutDirection.AwayFromOrigin;
+            cutOffSettings1.MinSegmentLength = 0.05D;
+            cutOffSettings1.Overtravel = 0D;
+            cutOffSettings1.PartClearance = 0.02D;
+            previewBox.CutOffSettings = cutOffSettings1;
+            previewBox.DebugRemnantPriorities = null;
+            previewBox.DebugRemnants = null;
+            previewBox.Dock = System.Windows.Forms.DockStyle.Fill;
+            previewBox.DrawBounds = false;
+            previewBox.DrawCutDirection = false;
+            previewBox.DrawOffset = false;
+            previewBox.DrawOrigin = false;
+            previewBox.DrawPiercePoints = false;
+            previewBox.DrawRapid = false;
+            previewBox.FillParts = true;
+            previewBox.Location = new System.Drawing.Point(0, 0);
+            previewBox.Name = "previewBox";
+            previewBox.OffsetIncrementDistance = 10D;
+            previewBox.OffsetTolerance = 0.001D;
+            plate1.CutOffs = observableList_11;
+            plate1.CuttingParameters = null;
+            plate1.GrainAngle = 0D;
+            plate1.Parts = observableList_12;
+            plate1.PartSpacing = 0D;
+            plate1.Quadrant = 1;
+            plate1.Quantity = 0;
+            previewBox.Plate = plate1;
+            previewBox.RotateIncrementAngle = 10D;
+            previewBox.ShowBendLines = false;
+            previewBox.Size = new System.Drawing.Size(318, 363);
+            previewBox.Status = "Select";
+            previewBox.TabIndex = 4;
+            previewBox.TabStop = false;
+            // 
+            // parametersPanel
+            // 
+            parametersPanel.AutoScroll = true;
+            parametersPanel.Dock = System.Windows.Forms.DockStyle.Right;
+            parametersPanel.Location = new System.Drawing.Point(318, 0);
+            parametersPanel.Name = "parametersPanel";
+            parametersPanel.Padding = new System.Windows.Forms.Padding(8, 0, 0, 0);
+            parametersPanel.Size = new System.Drawing.Size(260, 363);
+            parametersPanel.TabIndex = 5;
+            // 
+            // buttonPanel
+            // 
+            buttonPanel.Controls.Add(addButton);
+            buttonPanel.Controls.Add(closeButton);
+            buttonPanel.Dock = System.Windows.Forms.DockStyle.Fill;
+            buttonPanel.Location = new System.Drawing.Point(9, 479);
+            buttonPanel.Name = "buttonPanel";
+            buttonPanel.Size = new System.Drawing.Size(578, 38);
+            buttonPanel.TabIndex = 2;
+            // 
+            // addButton
+            // 
+            addButton.Anchor = System.Windows.Forms.AnchorStyles.Top | System.Windows.Forms.AnchorStyles.Right;
+            addButton.Location = new System.Drawing.Point(379, 5);
+            addButton.Name = "addButton";
+            addButton.Size = new System.Drawing.Size(100, 30);
+            addButton.TabIndex = 0;
+            addButton.Text = "Add to Nest";
+            addButton.UseVisualStyleBackColor = true;
+            // 
+            // closeButton
+            // 
+            closeButton.Anchor = System.Windows.Forms.AnchorStyles.Top | System.Windows.Forms.AnchorStyles.Right;
+            closeButton.DialogResult = System.Windows.Forms.DialogResult.Cancel;
+            closeButton.Location = new System.Drawing.Point(485, 5);
+            closeButton.Name = "closeButton";
+            closeButton.Size = new System.Drawing.Size(90, 30);
+            closeButton.TabIndex = 1;
+            closeButton.Text = "Close";
+            closeButton.UseVisualStyleBackColor = true;
+            // 
+            // ShapeLibraryForm
+            // 
+            AutoScaleMode = System.Windows.Forms.AutoScaleMode.None;
+            CancelButton = closeButton;
+            ClientSize = new System.Drawing.Size(750, 520);
+            Controls.Add(splitContainer);
+            Font = new System.Drawing.Font("Segoe UI", 9.75F);
+            MinimizeBox = false;
+            MinimumSize = new System.Drawing.Size(600, 400);
+            Name = "ShapeLibraryForm";
+            ShowIcon = false;
+            ShowInTaskbar = false;
+            StartPosition = System.Windows.Forms.FormStartPosition.CenterParent;
+            Text = "Shape Library";
+            splitContainer.Panel1.ResumeLayout(false);
+            splitContainer.Panel2.ResumeLayout(false);
+            ((System.ComponentModel.ISupportInitialize)splitContainer).EndInit();
+            splitContainer.ResumeLayout(false);
+            layoutTable.ResumeLayout(false);
+            layoutTable.PerformLayout();
+            fieldsTable.ResumeLayout(false);
+            fieldsTable.PerformLayout();
+            ((System.ComponentModel.ISupportInitialize)quantityUpDown).EndInit();
+            contentPanel.ResumeLayout(false);
+            buttonPanel.ResumeLayout(false);
+            ResumeLayout(false);
+        }
+
+        #endregion
+
+        private System.Windows.Forms.SplitContainer splitContainer;
+        private System.Windows.Forms.ListBox shapeListBox;
+        private System.Windows.Forms.TableLayoutPanel layoutTable;
+        private System.Windows.Forms.TableLayoutPanel fieldsTable;
+        private System.Windows.Forms.Label nameLabel;
+        private System.Windows.Forms.TextBox nameTextBox;
+        private System.Windows.Forms.Label qtyLabel;
+        private Controls.NumericUpDown quantityUpDown;
+        private System.Windows.Forms.Label configLabel;
+        private System.Windows.Forms.ComboBox configComboBox;
+        private System.Windows.Forms.Panel contentPanel;
+        private Controls.ShapePreviewControl previewBox;
+        private System.Windows.Forms.Panel parametersPanel;
+        private System.Windows.Forms.Panel buttonPanel;
+        private System.Windows.Forms.Button addButton;
+        private System.Windows.Forms.Button closeButton;
+    }
+}

OpenNest/Forms/ShapeLibraryForm.cs

@@ -0,0 +1,322 @@
+using OpenNest.Shapes;
+using System;
+using System.Collections.Generic;
+using System.Drawing;
+using System.IO;
+using System.Linq;
+using System.Reflection;
+using System.Text.Json;
+using System.Text.RegularExpressions;
+using System.Windows.Forms;
+
+namespace OpenNest.Forms
+{
+    public partial class ShapeLibraryForm : Form
+    {
+        private static readonly JsonSerializerOptions JsonOptions = new JsonSerializerOptions
+        {
+            PropertyNameCaseInsensitive = true
+        };
+
+        private readonly List<Drawing> addedDrawings = new List<Drawing>();
+        private readonly List<ShapeEntry> shapeEntries = new List<ShapeEntry>();
+        private readonly List<ParameterBinding> parameterBindings = new List<ParameterBinding>();
+
+        private ShapeEntry selectedEntry;
+        private bool suppressPreview;
+
+        public ShapeLibraryForm()
+        {
+            InitializeComponent();
+            DiscoverShapes();
+            PopulateShapeList();
+
+            shapeListBox.DrawItem += ShapeListBox_DrawItem;
+            shapeListBox.SelectedIndexChanged += ShapeListBox_SelectedIndexChanged;
+            configComboBox.SelectedIndexChanged += ConfigComboBox_SelectedIndexChanged;
+            addButton.Click += AddButton_Click;
+            closeButton.Click += (s, e) => Close();
+
+            if (shapeListBox.Items.Count > 0)
+                shapeListBox.SelectedIndex = 0;
+        }
+
+        public List<Drawing> GetDrawings() => addedDrawings;
+
+        private void DiscoverShapes()
+        {
+            var baseType = typeof(ShapeDefinition);
+            var shapeTypes = baseType.Assembly.GetTypes()
+                .Where(t => t.IsClass && !t.IsAbstract && baseType.IsAssignableFrom(t))
+                .OrderBy(t => t.Name)
+                .ToList();
+
+            var configDir = Path.Combine(AppDomain.CurrentDomain.BaseDirectory, "Configurations");
+
+            foreach (var type in shapeTypes)
+            {
+                var entry = new ShapeEntry { ShapeType = type };
+                entry.DisplayName = FriendlyName(type.Name);
+
+                var configPath = Path.Combine(configDir, type.Name + ".json");
+                if (File.Exists(configPath))
+                    entry.Configurations = LoadConfigurations(type, configPath);
+
+                shapeEntries.Add(entry);
+            }
+        }
+
+        private List<ShapeDefinition> LoadConfigurations(Type shapeType, string path)
+        {
+            try
+            {
+                var json = File.ReadAllText(path);
+                var listType = typeof(List<>).MakeGenericType(shapeType);
+                var list = JsonSerializer.Deserialize(json, listType, JsonOptions);
+                return ((System.Collections.IEnumerable)list).Cast<ShapeDefinition>().ToList();
+            }
+            catch
+            {
+                return null;
+            }
+        }
+
+        private void PopulateShapeList()
+        {
+            foreach (var entry in shapeEntries)
+                shapeListBox.Items.Add(entry);
+        }
+
+        private void ShapeListBox_DrawItem(object sender, DrawItemEventArgs e)
+        {
+            if (e.Index < 0) return;
+
+            e.DrawBackground();
+
+            var entry = (ShapeEntry)shapeListBox.Items[e.Index];
+            var textColor = (e.State & DrawItemState.Selected) != 0
+                ? SystemColors.HighlightText
+                : SystemColors.ControlText;
+
+            var text = entry.DisplayName;
+            if (entry.HasConfigurations)
+                text += $"  ({entry.Configurations.Count})";
+
+            using (var brush = new SolidBrush(textColor))
+            {
+                var format = new StringFormat { LineAlignment = StringAlignment.Center };
+                var rect = new RectangleF(8, e.Bounds.Y, e.Bounds.Width - 8, e.Bounds.Height);
+                e.Graphics.DrawString(text, e.Font, brush, rect, format);
+            }
+
+            e.DrawFocusRectangle();
+        }
+
+        private void ShapeListBox_SelectedIndexChanged(object sender, EventArgs e)
+        {
+            if (shapeListBox.SelectedIndex < 0) return;
+
+            selectedEntry = (ShapeEntry)shapeListBox.SelectedItem;
+            suppressPreview = true;
+
+            var hasConfigs = selectedEntry.HasConfigurations;
+            configLabel.Visible = hasConfigs;
+            configComboBox.Visible = hasConfigs;
+
+            if (hasConfigs)
+            {
+                configComboBox.Items.Clear();
+                foreach (var cfg in selectedEntry.Configurations)
+                    configComboBox.Items.Add(cfg.Name);
+
+                configComboBox.SelectedIndex = 0;
+            }
+            else
+            {
+                nameTextBox.Text = selectedEntry.DisplayName;
+                var defaults = (ShapeDefinition)Activator.CreateInstance(selectedEntry.ShapeType);
+                defaults.SetPreviewDefaults();
+                BuildParameterControls(selectedEntry.ShapeType, defaults);
+            }
+
+            suppressPreview = false;
+            UpdatePreview();
+        }
+
+        private void ConfigComboBox_SelectedIndexChanged(object sender, EventArgs e)
+        {
+            if (configComboBox.SelectedIndex < 0 || selectedEntry == null) return;
+
+            var config = selectedEntry.Configurations[configComboBox.SelectedIndex];
+            nameTextBox.Text = config.Name;
+
+            suppressPreview = true;
+            BuildParameterControls(selectedEntry.ShapeType, config);
+            suppressPreview = false;
+            UpdatePreview();
+        }
+
+        private void BuildParameterControls(Type shapeType, ShapeDefinition sourceValues)
+        {
+            parametersPanel.SuspendLayout();
+            parametersPanel.Controls.Clear();
+            parameterBindings.Clear();
+
+            var props = shapeType.GetProperties(BindingFlags.Public | BindingFlags.Instance | BindingFlags.DeclaredOnly)
+                .Where(p => p.CanRead && p.CanWrite && p.Name != "Name")
+                .ToArray();
+
+            var panelWidth = parametersPanel.ClientSize.Width - parametersPanel.Padding.Horizontal;
+            var y = 4;
+
+            foreach (var prop in props)
+            {
+                var label = new Label
+                {
+                    Text = FriendlyName(prop.Name),
+                    Location = new Point(parametersPanel.Padding.Left, y),
+                    AutoSize = true
+                };
+
+                y += 18;
+
+                var tb = new TextBox
+                {
+                    Location = new Point(parametersPanel.Padding.Left, y),
+                    Width = panelWidth,
+                    Anchor = AnchorStyles.Top | AnchorStyles.Left | AnchorStyles.Right
+                };
+
+                if (sourceValues != null)
+                {
+                    if (prop.PropertyType == typeof(int))
+                        tb.Text = ((int)prop.GetValue(sourceValues)).ToString();
+                    else
+                        tb.Text = ((double)prop.GetValue(sourceValues)).ToString("G");
+                }
+
+                tb.TextChanged += (s, ev) => UpdatePreview();
+
+                parameterBindings.Add(new ParameterBinding { Property = prop, Control = tb });
+
+                parametersPanel.Controls.Add(label);
+                parametersPanel.Controls.Add(tb);
+
+                y += 30;
+            }
+
+            parametersPanel.ResumeLayout(true);
+        }
+
+        private void UpdatePreview()
+        {
+            if (suppressPreview || selectedEntry == null) return;
+
+            try
+            {
+                var shape = CreateShapeFromInputs();
+                if (shape == null) return;
+
+                var drawing = shape.GetDrawing();
+                previewBox.ShowDrawing(drawing);
+
+                if (drawing?.Program != null)
+                {
+                    var bb = drawing.Program.BoundingBox();
+                    previewBox.SetInfo(
+                        nameTextBox.Text,
+                        string.Format("{0:F3} x {1:F3}", bb.Size.Length, bb.Size.Width));
+                }
+            }
+            catch
+            {
+                previewBox.ShowDrawing(null);
+            }
+        }
+
+        private ShapeDefinition CreateShapeFromInputs()
+        {
+            var shape = (ShapeDefinition)Activator.CreateInstance(selectedEntry.ShapeType);
+            shape.Name = nameTextBox.Text;
+
+            foreach (var binding in parameterBindings)
+            {
+                var tb = (TextBox)binding.Control;
+
+                if (binding.Property.PropertyType == typeof(int))
+                {
+                    if (int.TryParse(tb.Text, out var intVal))
+                    {
+                        binding.Property.SetValue(shape, intVal);
+                        tb.ForeColor = SystemColors.WindowText;
+                    }
+                    else
+                    {
+                        tb.ForeColor = Color.Red;
+                        return null;
+                    }
+                }
+                else
+                {
+                    var val = ArchUnits.GetLengthInches(tb);
+                    if (double.IsNaN(val))
+                        return null;
+
+                    binding.Property.SetValue(shape, val);
+                }
+            }
+
+            return shape;
+        }
+
+        private void AddButton_Click(object sender, EventArgs e)
+        {
+            try
+            {
+                var shape = CreateShapeFromInputs();
+                if (shape == null) return;
+
+                var drawing = shape.GetDrawing();
+                drawing.Color = Drawing.GetNextColor();
+                drawing.Quantity.Required = (int)quantityUpDown.Value;
+
+                addedDrawings.Add(drawing);
+                DialogResult = DialogResult.OK;
+
+                addButton.Text = $"Added ({addedDrawings.Count})";
+            }
+            catch (Exception ex)
+            {
+                MessageBox.Show(
+                    $"Failed to create shape: {ex.Message}",
+                    "Error",
+                    MessageBoxButtons.OK,
+                    MessageBoxIcon.Warning);
+            }
+        }
+
+        private static string FriendlyName(string name)
+        {
+            if (name.EndsWith("Shape"))
+                name = name.Substring(0, name.Length - 5);
+
+            return Regex.Replace(name, @"(?<=[a-z0-9])([A-Z])", " $1");
+        }
+
+        private class ShapeEntry
+        {
+            public Type ShapeType { get; set; }
+            public string DisplayName { get; set; }
+            public List<ShapeDefinition> Configurations { get; set; }
+            public bool HasConfigurations => Configurations != null && Configurations.Count > 0;
+
+            public override string ToString() => DisplayName;
+        }
+
+        private class ParameterBinding
+        {
+            public PropertyInfo Property { get; set; }
+            public Control Control { get; set; }
+        }
+    }
+}

OpenNest/Forms/ShapeLibraryForm.resx

@@ -0,0 +1,120 @@
+<?xml version="1.0" encoding="utf-8"?>
+<root>
+  <!--
+    Microsoft ResX Schema
+
+    Version 2.0
+
+    The primary goals of this format is to allow a simple XML format
+    that is mostly human readable. The generation and parsing of the
+    various data types are done through the TypeConverter classes
+    associated with the data types.
+
+    Example:
+
+    ... ado.net/XML headers & schema ...
+    <resheader name="resmimetype">text/microsoft-resx</resheader>
+    <resheader name="version">2.0</resheader>
+    <resheader name="reader">System.Resources.ResXResourceReader, System.Windows.Forms, ...</resheader>
+    <resheader name="writer">System.Resources.ResXResourceWriter, System.Windows.Forms, ...</resheader>
+    <data name="Name1"><value>this is my long string</value><comment>this is a comment</comment></data>
+    <data name="Color1" type="System.Drawing.Color, System.Drawing">Blue</data>
+    <data name="Bitmap1" mimetype="application/x-microsoft.net.object.binary.base64">
+        <value>[base64 mime encoded serialized .NET Framework object]</value>
+    </data>
+    <data name="Icon1" type="System.Drawing.Icon, System.Drawing" mimetype="application/x-microsoft.net.object.bytearray.base64">
+        <value>[base64 mime encoded string representing a byte array form of the .NET Framework object]</value>
+        <comment>This is a comment</comment>
+    </data>
+
+    There are any number of "resheader" rows that contain simple
+    name/value pairs.
+
+    Each data row contains a name, and value. The row also contains a
+    type or mimetype. Type corresponds to a .NET class that support
+    text/value conversion through the TypeConverter architecture.
+    Classes that don't support this are serialized and stored with the
+    mimetype set.
+
+    The mimetype is used for serialized objects, and tells the
+    ResXResourceReader how to depersist the object. This is currently not
+    extensible. For a given mimetype the value must be set accordingly:
+
+    Note - application/x-microsoft.net.object.binary.base64 is the format
+    that the ResXResourceWriter will generate, however the reader can
+    read any of the formats listed below.
+
+    mimetype: application/x-microsoft.net.object.binary.base64
+    value   : The object must be serialized with
+            : System.Runtime.Serialization.Formatters.Binary.BinaryFormatter
+            : and then encoded with base64 encoding.
+
+    mimetype: application/x-microsoft.net.object.soap.base64
+    value   : The object must be serialized with
+            : System.Runtime.Serialization.Formatters.Soap.SoapFormatter
+            : and then encoded with base64 encoding.
+
+    mimetype: application/x-microsoft.net.object.bytearray.base64
+    value   : The object must be serialized into a byte array
+            : using a System.ComponentModel.TypeConverter
+            : and then encoded with base64 encoding.
+    -->
+  <xsd:schema id="root" xmlns="" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:msdata="urn:schemas-microsoft-com:xml-msdata">
+    <xsd:import namespace="http://www.w3.org/XML/1998/namespace" />
+    <xsd:element name="root" msdata:IsDataSet="true">
+      <xsd:complexType>
+        <xsd:choice maxOccurs="unbounded">
+          <xsd:element name="metadata">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" />
+              </xsd:sequence>
+              <xsd:attribute name="name" use="required" type="xsd:string" />
+              <xsd:attribute name="type" type="xsd:string" />
+              <xsd:attribute name="mimetype" type="xsd:string" />
+              <xsd:attribute ref="xml:space" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="assembly">
+            <xsd:complexType>
+              <xsd:attribute name="alias" type="xsd:string" />
+              <xsd:attribute name="name" type="xsd:string" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="data">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />
+                <xsd:element name="comment" type="xsd:string" minOccurs="0" msdata:Ordinal="2" />
+              </xsd:sequence>
+              <xsd:attribute name="name" type="xsd:string" use="required" msdata:Ordinal="1" />
+              <xsd:attribute name="type" type="xsd:string" msdata:Ordinal="3" />
+              <xsd:attribute name="mimetype" type="xsd:string" msdata:Ordinal="4" />
+              <xsd:attribute ref="xml:space" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="resheader">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />
+              </xsd:sequence>
+              <xsd:attribute name="name" type="xsd:string" use="required" />
+            </xsd:complexType>
+          </xsd:element>
+        </xsd:choice>
+      </xsd:complexType>
+    </xsd:element>
+  </xsd:schema>
+  <resheader name="resmimetype">
+    <value>text/microsoft-resx</value>
+  </resheader>
+  <resheader name="version">
+    <value>2.0</value>
+  </resheader>
+  <resheader name="reader">
+    <value>System.Resources.ResXResourceReader, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
+  </resheader>
+  <resheader name="writer">
+    <value>System.Resources.ResXResourceWriter, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
+  </resheader>
+</root>

OpenNest/OpenNest.csproj

@@ -10,6 +10,11 @@
   <ItemGroup>
     <Compile Remove="Controls\LayoutViewGL.cs" />
   </ItemGroup>
+  <ItemGroup>
+    <Content Include="Configurations\**\*.json">
+      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
+    </Content>
+  </ItemGroup>
   <ItemGroup>
     <ProjectReference Include="..\OpenNest.Api\OpenNest.Api.csproj" />
     <ProjectReference Include="..\OpenNest.Core\OpenNest.Core.csproj" />