fix: remove Windows-specific TFM for Linux/Docker compatibility

Change net8.0-windows to net8.0 in Core, IO, and Engine projects so
the libraries can be consumed in Docker containers running on Linux.

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

CLAUDE.md

@@ -120,4 +120,3 @@ Always keep `README.md` and `CLAUDE.md` up to date when making changes that affe
 - **Cut-off materialization lifecycle**: `CutOff` objects live on `Plate.CutOffs`. Each generates a `Drawing` (with `IsCutOff = true`) whose `Program` contains trimmed line segments. `Plate.RegenerateCutOffs(settings)` removes old cut-off Parts, recomputes programs, and re-adds them to `Plate.Parts`. Regeneration triggers: cut-off add/remove/move, part drag complete, fill complete, plate transform. Cut-off Parts are excluded from quantity tracking, utilization, overlap detection, and nest file serialization (programs are regenerated from definitions on load).
 - **User-defined G-code variables**: Programs can contain named variable definitions (`name = expression [inline] [global]`) referenced in coordinates with `$name`. Variables resolve to doubles at parse time for geometry/nesting. `VariableRefs` on `Motion`/`Feedrate` track the symbolic link so post processors can emit machine variable references. Cincinnati post maps non-inline variables to numbered machine variables (`#200+`) with descriptive comments. Global variables share a number across programs; local variables get per-drawing numbers. `ProgramReader` uses a two-pass parse (collect definitions, then parse G-code with substitution). `NestWriter` serializes definitions and `$references` back to text for round-trip fidelity.
 - **CAD import pipeline**: All "DXF → Drawing" conversion goes through `OpenNest.IO.CadImporter`. The UI form uses `Import` on file load (storing the mutable result in a `FileListItem`) and `BuildDrawing` on save (passing the user's current visible entities and bends). Console, MCP, API, and Training projects use `ImportDrawing` for headless conversion. This guarantees all callers produce drawings with the same shape: pierce-point `Source.Offset`, stable `SourceEntities` with GUIDs, `SuppressedEntityIds`, detected bends, and metadata.
-- **GravographIS engrave/cut passes**: The `OpenNest.Posts.GravographIS` post splits geometry by `LayerType` into ordered tool passes — engrave (`Scribe`) then cut (`Cut`/`Leadin`/`Leadout`); `Display` is skipped. `ConvertGeometry` tags DXF layers `ENGRAVE`/`ETCH` (lines, arcs, circles) as `Scribe`; the layer round-trips through `.nest` via `NestWriter`/`ProgramReader`. `NestPolylineExtractor.ExtractLayered` carries `LayerType` per polyline (splitting a continuous chain at any layer change); `GravographISPostProcessor.BuildPasses` groups them and `GravographISWriter.Write(IReadOnlyList<GravographPass>, …)` emits each pass at its own feed/depth, parking to origin and emitting an operator pause (motor off → aux off → `LB` console message → motor on) before any pass whose config has `PauseBefore`. Per-pass parameters live in `GravographISPostConfig` (an `IConfigurablePostProcessor` config with `Engrave`/`Cut` `LayerCutConfig` blocks), edited in the shared `PostProcessorConfigForm` PropertyGrid and persisted to JSON. The cut block pauses by default so the operator can swap/adjust the tool (the spring-floated spindle means programmed `DZ` depth is not the real cut depth).

OpenNest.Core/Converters/ConvertGeometry.cs

@@ -87,15 +87,14 @@ namespace OpenNest.Converters
 
             lastpt = endpt;
 
-            var layer = ClassifyLayer(arc);
             var sweep = System.Math.Abs(arc.SweepAngle());
             if (sweep < Tolerance.Epsilon || sweep.IsEqualTo(Angle.TwoPI))
             {
-                pgm.Codes.Add(new LinearMove(endpt) { Layer = layer });
+                pgm.LineTo(endpt);
             }
             else
             {
-                pgm.Codes.Add(new ArcMove(endpt, arc.Center, arc.IsReversed ? RotationType.CW : RotationType.CCW) { Layer = layer });
+                pgm.ArcTo(endpt, arc.Center, arc.IsReversed ? RotationType.CW : RotationType.CCW);
             }
 
             return lastpt;
@@ -108,7 +107,7 @@ namespace OpenNest.Converters
             if (startpt.DistanceTo(lastpt) > Tolerance.ChainTolerance)
                 pgm.MoveTo(startpt);
 
-            pgm.Codes.Add(new ArcMove(startpt, circle.Center, circle.Rotation) { Layer = ClassifyLayer(circle) });
+            pgm.ArcTo(startpt, circle.Center, circle.Rotation);
 
             lastpt = startpt;
             return lastpt;
@@ -119,22 +118,13 @@ namespace OpenNest.Converters
             if (line.StartPoint.DistanceTo(lastpt) > Tolerance.ChainTolerance)
                 pgm.MoveTo(line.StartPoint);
 
-            pgm.Codes.Add(new LinearMove(line.EndPoint) { Layer = ClassifyLayer(line) });
+            var move = new LinearMove(line.EndPoint);
+            if (string.Equals(line.Layer?.Name, "ETCH", System.StringComparison.OrdinalIgnoreCase))
+                move.Layer = LayerType.Scribe;
+            pgm.Codes.Add(move);
 
             lastpt = line.EndPoint;
             return lastpt;
         }
-
-        // Engrave/etch geometry maps to Scribe so the post processor can treat it as a
-        // separate tool pass; everything else keeps the move's default Cut layer.
-        private static LayerType ClassifyLayer(Entity geo)
-        {
-            var name = geo.Layer?.Name;
-            if (string.Equals(name, "ENGRAVE", System.StringComparison.OrdinalIgnoreCase) ||
-                string.Equals(name, "ETCH", System.StringComparison.OrdinalIgnoreCase))
-                return LayerType.Scribe;
-
-            return LayerType.Cut;
-        }
     }
 }

OpenNest.Core/Geometry/ArcFit.cs

@@ -57,14 +57,13 @@ namespace OpenNest.Geometry
         }
 
         /// <summary>
-        /// Fits a circular arc that passes exactly through both the first and last points
+        /// Fits a circular arc constrained to be tangent to the given directions at both
-        /// while matching the given endpoint tangents as closely as possible. For any
+        /// the first and last points. The center lies at the intersection of the normals
-        /// circle through two points, the tangents at those points make equal mirrored
+        /// at P1 and Pn, guaranteeing the arc departs P1 in the start direction and arrives
-        /// angles with the chord, so the achievable inscribed angle is the average of the
+        /// at Pn in the end direction. Uses the radius from P1 (exact start tangent);
-        /// two requested ones — when the requested tangents are consistent with a single
+        /// deviation includes any endpoint gap at Pn.
-        /// circular arc, both are matched exactly.
         /// </summary>
-        internal static (Vector center, double radius, double deviation) FitThroughEndpointsWithTangents(
+        internal static (Vector center, double radius, double deviation) FitWithDualTangent(
             List<Vector> points, Vector startTangent, Vector endTangent)
         {
             if (points.Count < 3)
@@ -73,39 +72,42 @@ namespace OpenNest.Geometry
             var p1 = points[0];
             var pn = points[^1];
 
+            var stLen = System.Math.Sqrt(startTangent.X * startTangent.X + startTangent.Y * startTangent.Y);
+            var etLen = System.Math.Sqrt(endTangent.X * endTangent.X + endTangent.Y * endTangent.Y);
+            if (stLen < 1e-10 || etLen < 1e-10)
+                return (Vector.Invalid, 0, double.MaxValue);
+
+            // Normal to start tangent at P1 (perpendicular)
+            var n1x = -startTangent.Y / stLen;
+            var n1y = startTangent.X / stLen;
+
+            // Normal to end tangent at Pn
+            var n2x = -endTangent.Y / etLen;
+            var n2y = endTangent.X / etLen;
+
+            // Solve: P1 + t1*N1 = Pn + t2*N2
+            var det = n1x * (-n2y) - (-n2x) * n1y;
+            if (System.Math.Abs(det) < 1e-10)
+                return (Vector.Invalid, 0, double.MaxValue);
+
             var dx = pn.X - p1.X;
             var dy = pn.Y - p1.Y;
-            var chordLen = System.Math.Sqrt(dx * dx + dy * dy);
+            var t1 = (dx * (-n2y) - (-n2x) * dy) / det;
-            if (chordLen < 1e-10)
+
+            var cx = p1.X + t1 * n1x;
+            var cy = p1.Y + t1 * n1y;
+
+            // Use radius from P1 (guarantees exact start tangent and passes through P1)
+            var r1 = System.Math.Sqrt((cx - p1.X) * (cx - p1.X) + (cy - p1.Y) * (cy - p1.Y));
+            if (r1 < 1e-10)
                 return (Vector.Invalid, 0, double.MaxValue);
 
-            var ux = dx / chordLen;
+            // Measure endpoint gap at Pn
-            var uy = dy / chordLen;
+            var r2 = System.Math.Sqrt((cx - pn.X) * (cx - pn.X) + (cy - pn.Y) * (cy - pn.Y));
+            var endpointDev = System.Math.Abs(r2 - r1);
 
-            // Inscribed angle between chord and tangent at each endpoint (mirrored at Pn)
+            var interiorDev = MaxRadialDeviation(points, cx, cy, r1);
-            var theta1 = SignedAngle(ux, uy, startTangent);
+            return (new Vector(cx, cy), r1, System.Math.Max(endpointDev, interiorDev));
-            var theta2 = -SignedAngle(ux, uy, endTangent);
-            var theta = (theta1 + theta2) / 2;
-
-            // Nearly straight or degenerate (sweep would exceed ~356 degrees)
-            if (System.Math.Abs(theta) < 1e-3 || System.Math.Abs(theta) > System.Math.PI * 0.99)
-                return (Vector.Invalid, 0, double.MaxValue);
-
-            var halfChord = chordLen / 2;
-            var radius = halfChord / System.Math.Abs(System.Math.Sin(theta));
-            var d = -halfChord / System.Math.Tan(theta);
-
-            var cx = (p1.X + pn.X) / 2 + d * -uy;
-            var cy = (p1.Y + pn.Y) / 2 + d * ux;
-
-            return (new Vector(cx, cy), radius, MaxRadialDeviation(points, cx, cy, radius));
-        }
-
-        private static double SignedAngle(double ux, double uy, Vector to)
-        {
-            var len = System.Math.Sqrt(to.X * to.X + to.Y * to.Y);
-            if (len < 1e-10) return 0;
-            return System.Math.Atan2(ux * to.Y - uy * to.X, ux * to.X + uy * to.Y);
         }
 
         /// <summary>

OpenNest.Core/Geometry/GeometrySimplifier.cs

@@ -374,8 +374,11 @@ public class GeometrySimplifier
         var points = CollectPoints(entities, start, k);
         if (points.Count < 3) return null;
 
-        var startTangent = EstimateStartTangent(entities, start, points, chainedTangent);
+        var startTangent = chainedTangent.IsValid()
-        var endTangent = EstimateEndTangent(entities, k, points);
+            ? chainedTangent
+            : new Vector(points[1].X - points[0].X, points[1].Y - points[0].Y);
+
+        var endTangent = GetExitDirection(entities[k]);
         var (center, radius, dev) = TryFit(points, startTangent, endTangent);
         if (!center.IsValid()) return null;
 
@@ -383,10 +386,8 @@ public class GeometrySimplifier
         while (k + 1 <= runEnd)
         {
             var extPoints = CollectPoints(entities, start, k + 1);
-            if (extPoints.Count < 3) break;
+            var extEndTangent = GetExitDirection(entities[k + 1]);
-
+            var (nc, nr, nd) = extPoints.Count >= 3 ? TryFit(extPoints, startTangent, extEndTangent) : (Vector.Invalid, 0, 0d);
-            var extEndTangent = EstimateEndTangent(entities, k + 1, extPoints);
-            var (nc, nr, nd) = TryFit(extPoints, startTangent, extEndTangent);
             if (!nc.IsValid()) break;
 
             k++;
@@ -406,172 +407,37 @@ public class GeometrySimplifier
         return new ArcFitResult(center, radius, dev, points, k);
     }
 
-    private (Vector center, double radius, double deviation) TryFit(
+    private (Vector center, double radius, double deviation) TryFit(List<Vector> points, Vector startTangent, Vector endTangent)
-        List<Vector> points, TangentEstimate start, TangentEstimate end)
     {
-        foreach (var (center, radius, dev) in FitAttempts(points, start, end))
+        // Try dual-tangent fit first (matches direction at both endpoints)
+        if (endTangent.IsValid())
         {
+            var (dc, dr, dd) = ArcFit.FitWithDualTangent(points, startTangent, endTangent);
+            if (dc.IsValid() && dd <= Tolerance)
+            {
+                var isRev = SumSignedAngles(dc, points) < 0;
+                var aDev = MaxArcToSegmentDeviation(points, dc, dr, isRev);
+                if (aDev <= Tolerance)
+                    return (dc, dr, System.Math.Max(dd, aDev));
+            }
+        }
+
+        // Fall back to start-tangent-only, then mirror axis
+        var (center, radius, dev) = ArcFit.FitWithStartTangent(points, startTangent);
         if (!center.IsValid() || dev > Tolerance)
-                continue;
+            (center, radius, dev) = FitMirrorAxis(points);
+        if (!center.IsValid() || dev > Tolerance)
+            return (Vector.Invalid, 0, 0);
 
         // Check that the arc doesn't bulge away from the original line segments
         var isReversed = SumSignedAngles(center, points) < 0;
         var arcDev = MaxArcToSegmentDeviation(points, center, radius, isReversed);
         if (arcDev > Tolerance)
-                continue;
+            return (Vector.Invalid, 0, 0);
 
         return (center, radius, System.Math.Max(dev, arcDev));
     }
 
-        return (Vector.Invalid, 0, 0);
-    }
-
-    /// <summary>
-    /// Yields fit attempts in preference order. A trusted tangent (chained from the
-    /// previous arc, an adjacent original arc, or a long straight edge) is enforced
-    /// exactly on its side; otherwise the tangency error is balanced between both
-    /// endpoints. The unconstrained mirror-axis fit is the last resort. Every attempt
-    /// passes exactly through both endpoints, so no gaps are introduced.
-    /// </summary>
-    private IEnumerable<(Vector center, double radius, double deviation)> FitAttempts(
-        List<Vector> points, TangentEstimate start, TangentEstimate end)
-    {
-        if (start.Trusted && !end.Trusted)
-        {
-            yield return ArcFit.FitWithStartTangent(points, start.Direction);
-            yield return ArcFit.FitThroughEndpointsWithTangents(points, start.Direction, end.Direction);
-            yield return FitWithEndTangent(points, end.Direction);
-        }
-        else if (end.Trusted && !start.Trusted)
-        {
-            yield return FitWithEndTangent(points, end.Direction);
-            yield return ArcFit.FitThroughEndpointsWithTangents(points, start.Direction, end.Direction);
-            yield return ArcFit.FitWithStartTangent(points, start.Direction);
-        }
-        else
-        {
-            yield return ArcFit.FitThroughEndpointsWithTangents(points, start.Direction, end.Direction);
-            yield return ArcFit.FitWithStartTangent(points, start.Direction);
-            yield return FitWithEndTangent(points, end.Direction);
-        }
-
-        yield return FitMirrorAxis(points);
-    }
-
-    /// <summary>
-    /// Fits an arc through both endpoints with an exact tangent at the last point,
-    /// by running the start-tangent fit on the reversed point sequence.
-    /// </summary>
-    private static (Vector center, double radius, double deviation) FitWithEndTangent(
-        List<Vector> points, Vector endTangent)
-    {
-        var reversed = new List<Vector>(points);
-        reversed.Reverse();
-        return ArcFit.FitWithStartTangent(reversed, new Vector(-endTangent.X, -endTangent.Y));
-    }
-
-    /// <summary>
-    /// An estimated tangent direction at a fit endpoint. Trusted estimates come from
-    /// exact geometry (a chained arc, an adjacent original arc, or a long straight
-    /// edge) and are enforced exactly; untrusted ones are derived from the polyline
-    /// vertices and only guide the fit.
-    /// </summary>
-    private readonly record struct TangentEstimate(Vector Direction, bool Trusted);
-
-    /// <summary>Segment-length ratio above which a neighboring line counts as a true
-    /// straight edge (rather than another chord of the tessellated curve).</summary>
-    private const double NeighborEdgeFactor = 3.0;
-
-    private static TangentEstimate EstimateStartTangent(
-        List<Entity> entities, int start, List<Vector> points, Vector chainedTangent)
-    {
-        if (chainedTangent.IsValid())
-            return new TangentEstimate(chainedTangent, true);
-
-        if (entities[start] is Arc startArc)
-            return new TangentEstimate(GetEntryDirection(startArc), true);
-
-        var firstChordLen = points[0].DistanceTo(points[1]);
-        if (start > 0)
-        {
-            var prev = entities[start - 1];
-            var prevEnd = prev switch { Line l => l.EndPoint, Arc a => a.EndPoint(), _ => Vector.Invalid };
-            if (prevEnd.IsValid() && prevEnd.DistanceTo(points[0]) < 1e-6)
-            {
-                if (prev is Arc)
-                    return new TangentEstimate(GetExitDirection(prev), true);
-                if (prev is Line prevLine && prevLine.StartPoint.DistanceTo(prevLine.EndPoint) >= NeighborEdgeFactor * firstChordLen)
-                    return new TangentEstimate(GetExitDirection(prevLine), true);
-            }
-        }
-
-        var chord = new Vector(points[1].X - points[0].X, points[1].Y - points[0].Y);
-        if (points.Count >= 3)
-            return new TangentEstimate(EstimateVertexTangent(points[0], points[1], points[2], chord), false);
-        return new TangentEstimate(chord, false);
-    }
-
-    private static TangentEstimate EstimateEndTangent(List<Entity> entities, int k, List<Vector> points)
-    {
-        if (entities[k] is Arc endArc)
-            return new TangentEstimate(GetExitDirection(endArc), true);
-
-        var lastChordLen = points[^1].DistanceTo(points[^2]);
-        if (k + 1 < entities.Count)
-        {
-            var next = entities[k + 1];
-            var nextStart = next switch { Line l => l.StartPoint, Arc a => a.StartPoint(), _ => Vector.Invalid };
-            if (nextStart.IsValid() && nextStart.DistanceTo(points[^1]) < 1e-6)
-            {
-                if (next is Arc nextArc)
-                    return new TangentEstimate(GetEntryDirection(nextArc), true);
-                if (next is Line nextLine && nextLine.StartPoint.DistanceTo(nextLine.EndPoint) >= NeighborEdgeFactor * lastChordLen)
-                    return new TangentEstimate(GetExitDirection(nextLine), true);
-            }
-        }
-
-        var chord = new Vector(points[^1].X - points[^2].X, points[^1].Y - points[^2].Y);
-        if (points.Count >= 3)
-            return new TangentEstimate(EstimateVertexTangent(points[^1], points[^2], points[^3], chord), false);
-        return new TangentEstimate(chord, false);
-    }
-
-    /// <summary>
-    /// Estimates the curve tangent at a polyline vertex from the circle through it and
-    /// its two nearest neighbors. A raw chord direction is off from the true tangent by
-    /// half the chord's subtended angle; the circumcircle estimate removes that bias.
-    /// Falls back to the travel direction when the three points are collinear.
-    /// </summary>
-    private static Vector EstimateVertexTangent(Vector at, Vector b, Vector c, Vector travel)
-    {
-        var d = 2 * (at.X * (b.Y - c.Y) + b.X * (c.Y - at.Y) + c.X * (at.Y - b.Y));
-        if (System.Math.Abs(d) < 1e-14)
-            return travel;
-
-        var sqA = at.X * at.X + at.Y * at.Y;
-        var sqB = b.X * b.X + b.Y * b.Y;
-        var sqC = c.X * c.X + c.Y * c.Y;
-        var cx = (sqA * (b.Y - c.Y) + sqB * (c.Y - at.Y) + sqC * (at.Y - b.Y)) / d;
-        var cy = (sqA * (c.X - b.X) + sqB * (at.X - c.X) + sqC * (b.X - at.X)) / d;
-
-        var tangent = new Vector(-(at.Y - cy), at.X - cx);
-        if (tangent.X * travel.X + tangent.Y * travel.Y < 0)
-            tangent = new Vector(-tangent.X, -tangent.Y);
-        return tangent;
-    }
-
-    /// <summary>
-    /// Returns the entry direction (tangent at start point) of an entity.
-    /// </summary>
-    private static Vector GetEntryDirection(Entity entity) => entity switch
-    {
-        Line line => new Vector(line.EndPoint.X - line.StartPoint.X, line.EndPoint.Y - line.StartPoint.Y),
-        Arc arc => arc.IsReversed
-            ? new Vector(System.Math.Sin(arc.StartAngle), -System.Math.Cos(arc.StartAngle))
-            : new Vector(-System.Math.Sin(arc.StartAngle), System.Math.Cos(arc.StartAngle)),
-        _ => Vector.Invalid,
-    };
-
     /// <summary>
     /// Computes the tangent direction at the last point of a fitted arc,
     /// used to chain tangent continuity to the next arc.

OpenNest.Core/OpenNest.Core.csproj

@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFramework>net8.0-windows</TargetFramework>
+    <TargetFramework>net8.0</TargetFramework>
     <RootNamespace>OpenNest</RootNamespace>
     <AssemblyName>OpenNest.Core</AssemblyName>
   </PropertyGroup>

OpenNest.Engine/OpenNest.Engine.csproj

@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFramework>net8.0-windows</TargetFramework>
+    <TargetFramework>net8.0</TargetFramework>
     <RootNamespace>OpenNest</RootNamespace>
     <AssemblyName>OpenNest.Engine</AssemblyName>
   </PropertyGroup>

OpenNest.IO/Dxf.cs

@@ -242,7 +242,6 @@ namespace OpenNest.IO
             public ExportContext()
             {
                 Document = new CadDocument();
-                Document.Header.Version = ACadVersion.AC1018;
 
                 CutLayer = new Layer("Cut") { Color = new Color(1) };
                 RapidLayer = new Layer("Rapid") { Color = new Color(5) };

OpenNest.IO/OpenNest.IO.csproj

@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFramework>net8.0-windows</TargetFramework>
+    <TargetFramework>net8.0</TargetFramework>
     <RootNamespace>OpenNest.IO</RootNamespace>
     <AssemblyName>OpenNest.IO</AssemblyName>
   </PropertyGroup>

OpenNest.Posts.GravographIS/GravographISPostConfig.cs

@@ -1,81 +0,0 @@
-using System.ComponentModel;
-using OpenNest.CNC;
-
-namespace OpenNest.Posts.GravographIS
-{
-    /// <summary>
-    /// Cut parameters for one kind of pass (engrave or cut). Edited in the post
-    /// configuration PropertyGrid and persisted to JSON.
-    /// </summary>
-    [TypeConverter(typeof(ExpandableObjectConverter))]
-    public sealed class LayerCutConfig
-    {
-        [DisplayName("Feed (mm/sec)")]
-        [Description("XY and Z feed for this pass. Patches the VS and VZ wire commands.")]
-        public int FeedMmPerSec { get; set; } = 10;
-
-        [DisplayName("Depth (inches)")]
-        [Description("Programmed Z plunge (DZ). Note: the spring-floated spindle means this does not set actual cut depth — tool protrusion does.")]
-        public double Depth { get; set; } = 0.25;
-
-        [DisplayName("Pause Before")]
-        [Description("Stop the spindle and prompt the operator before this pass begins, so the tool can be swapped/adjusted.")]
-        public bool PauseBefore { get; set; }
-
-        [DisplayName("Pause Message")]
-        [Description("Message shown on the controller during the pause.")]
-        public string PauseMessage { get; set; } = "";
-
-        public override string ToString() => $"{FeedMmPerSec} mm/s, {Depth:0.###}\"" + (PauseBefore ? ", pause" : "");
-    }
-
-    /// <summary>
-    /// Configuration for the Gravograph IS post processor: one <see cref="LayerCutConfig"/>
-    /// per cut kind. The engrave block applies to <see cref="LayerType.Scribe"/> paths,
-    /// the cut block to <see cref="LayerType.Cut"/>/<see cref="LayerType.Leadin"/>/<see cref="LayerType.Leadout"/>.
-    /// The cut block carries the tool-change pause by default.
-    /// </summary>
-    public sealed class GravographISPostConfig
-    {
-        [Category("Engrave (Scribe)")]
-        [DisplayName("Engrave")]
-        [Description("Parameters for engrave/scribe geometry (text).")]
-        public LayerCutConfig Engrave { get; set; } = new LayerCutConfig
-        {
-            FeedMmPerSec = 10,
-            Depth = 0.25,
-            PauseBefore = false,
-            PauseMessage = "",
-        };
-
-        [Category("Cut")]
-        [DisplayName("Cut")]
-        [Description("Parameters for cut geometry (outlines). Pauses for a tool change by default.")]
-        public LayerCutConfig Cut { get; set; } = new LayerCutConfig
-        {
-            FeedMmPerSec = 3,
-            Depth = 0.25,
-            PauseBefore = true,
-            PauseMessage = "Change tool",
-        };
-
-        /// <summary>
-        /// Returns the cut config a polyline of the given layer should use, or null
-        /// if the layer is non-cutting (<see cref="LayerType.Display"/>) and should be skipped.
-        /// </summary>
-        public LayerCutConfig ConfigFor(LayerType layer)
-        {
-            switch (layer)
-            {
-                case LayerType.Scribe:
-                    return Engrave;
-                case LayerType.Cut:
-                case LayerType.Leadin:
-                case LayerType.Leadout:
-                    return Cut;
-                default:
-                    return null;
-            }
-        }
-    }
-}

OpenNest.Posts.GravographIS/GravographISPostProcessor.cs

@@ -1,30 +1,16 @@
 using System;
-using System.Collections.Generic;
 using System.IO;
 using System.IO.Ports;
-using System.Text.Json;
-using System.Text.Json.Serialization;
 using System.Threading;
-using OpenNest.Geometry;
 
 namespace OpenNest.Posts.GravographIS
 {
     /// <summary>
     /// IPostProcessor implementation for the Gravograph IS8000. <see cref="Post(Nest, Stream)"/>
     /// writes the binary HPGL bytes. For serial streaming, use <see cref="Stream(Nest, string, Handshake, CancellationToken)"/>.
-    ///
-    /// Geometry is split by <see cref="OpenNest.CNC.LayerType"/> into an engrave pass
-    /// (Scribe) and a cut pass (Cut), each with its own feed/depth from <see cref="Config"/>.
-    /// The cut pass pauses by default so the operator can swap/adjust the tool.
     /// </summary>
-    public sealed class GravographISPostProcessor : IConfigurablePostProcessor
+    public sealed class GravographISPostProcessor : IPostProcessor
     {
-        private static readonly JsonSerializerOptions JsonOptions = new()
-        {
-            WriteIndented = true,
-            Converters = { new JsonStringEnumConverter() }
-        };
-
         public string Name => "Gravograph IS8000";
         public string Author => "OpenNest";
         public string Description => "Gravograph IS8000 mechanical engraver (binary HPGL over serial)";
@@ -37,53 +23,14 @@ namespace OpenNest.Posts.GravographIS
 
         public bool AllowReverse { get; set; } = true;
 
-        public GravographISPostConfig Config { get; }
-
-        object IConfigurablePostProcessor.Config => Config;
-
-        public GravographISPostProcessor()
-        {
-            var configPath = GetConfigPath();
-            if (File.Exists(configPath))
-            {
-                var json = File.ReadAllText(configPath);
-                Config = JsonSerializer.Deserialize<GravographISPostConfig>(json, JsonOptions)
-                    ?? new GravographISPostConfig();
-            }
-            else
-            {
-                Config = new GravographISPostConfig();
-                SaveConfig();
-            }
-        }
-
-        public GravographISPostProcessor(GravographISPostConfig config)
-        {
-            Config = config ?? throw new ArgumentNullException(nameof(config));
-        }
-
-        public void SaveConfig()
-        {
-            var configPath = GetConfigPath();
-            var json = JsonSerializer.Serialize(Config, JsonOptions);
-            File.WriteAllText(configPath, json);
-        }
-
-        private static string GetConfigPath()
-        {
-            var assemblyPath = typeof(GravographISPostProcessor).Assembly.Location;
-            var dir = Path.GetDirectoryName(assemblyPath);
-            var name = Path.GetFileNameWithoutExtension(assemblyPath);
-            return Path.Combine(dir, name + ".json");
-        }
-
         public void Post(Nest nest, Stream outputStream)
         {
             if (nest == null) throw new ArgumentNullException(nameof(nest));
             if (outputStream == null) throw new ArgumentNullException(nameof(outputStream));
 
-            var passes = BuildPasses(Extractor.ExtractLayered(nest));
+            var polylines = Extractor.Extract(nest);
-            new GravographISWriter(WriterOptions).Write(passes, outputStream);
+            var prepared = PolylinePrePass.Prepare(polylines, StitchTolerance, AllowReverse);
+            new GravographISWriter(WriterOptions).Write(prepared, outputStream);
         }
 
         public void Post(Nest nest, string outputFile)
@@ -92,52 +39,6 @@ namespace OpenNest.Posts.GravographIS
             Post(nest, fs);
         }
 
-        /// <summary>
-        /// Groups layer-tagged polylines into ordered tool passes: engrave (Scribe)
-        /// first, then cut. Each group is stitch/reverse-optimized independently.
-        /// Geometry whose layer maps to no config (Display) is skipped. When only one
-        /// group is present, a single pass is returned (and so the writer emits no pause).
-        /// </summary>
-        public IReadOnlyList<GravographPass> BuildPasses(IEnumerable<LayeredPolyline> polylines)
-        {
-            if (polylines == null) throw new ArgumentNullException(nameof(polylines));
-
-            var engrave = new List<IReadOnlyList<Vector>>();
-            var cut = new List<IReadOnlyList<Vector>>();
-
-            foreach (var poly in polylines)
-            {
-                if (poly == null) continue;
-                var block = Config.ConfigFor(poly.Layer);
-                if (block == null)
-                    continue; // non-cutting (Display) geometry
-                if (ReferenceEquals(block, Config.Engrave))
-                    engrave.Add(poly.Points);
-                else
-                    cut.Add(poly.Points);
-            }
-
-            var passes = new List<GravographPass>();
-            if (engrave.Count > 0)
-                passes.Add(MakePass(Config.Engrave, engrave));
-            if (cut.Count > 0)
-                passes.Add(MakePass(Config.Cut, cut));
-
-            return passes;
-        }
-
-        private GravographPass MakePass(LayerCutConfig block, List<IReadOnlyList<Vector>> polylines)
-        {
-            return new GravographPass
-            {
-                Polylines = PolylinePrePass.Prepare(polylines, StitchTolerance, AllowReverse),
-                FeedMmPerSec = block.FeedMmPerSec,
-                DepthInches = block.Depth,
-                PauseBefore = block.PauseBefore,
-                PauseMessage = block.PauseMessage ?? "",
-            };
-        }
-
         /// <summary>
         /// Buffers the encoded job in memory, then streams it to the named COM port.
         /// </summary>

OpenNest.Posts.GravographIS/GravographISWriter.cs

@@ -1,30 +1,10 @@
 using System;
 using System.Collections.Generic;
 using System.IO;
-using System.Text;
 using OpenNest.Geometry;
 
 namespace OpenNest.Posts.GravographIS
 {
-    /// <summary>
-    /// One tool pass: a run of polylines cut at a single feed/depth, optionally
-    /// preceded by an operator pause (to swap or adjust the tool). The Gravograph
-    /// post builds one pass for engrave and one for cut.
-    /// </summary>
-    public sealed class GravographPass
-    {
-        public IEnumerable<IReadOnlyList<Vector>> Polylines { get; set; }
-
-        public int FeedMmPerSec { get; set; }
-
-        public double DepthInches { get; set; }
-
-        /// <summary>When true, park to origin and prompt the operator before this pass.</summary>
-        public bool PauseBefore { get; set; }
-
-        public string PauseMessage { get; set; } = "";
-    }
-
     /// <summary>
     /// Encodes polylines (in inches) into the Gravograph IS8000 native "binary HPGL"
     /// wire format. The byte stream is byte-exact against captures from GravoStyle'98.
@@ -104,40 +84,12 @@ namespace OpenNest.Posts.GravographIS
         public void Write(IEnumerable<IReadOnlyList<Vector>> polylines, Stream output)
         {
             if (polylines == null) throw new ArgumentNullException(nameof(polylines));
-
-            // A single pass at the configured feed/depth — byte-identical to the
-            // original single-group output (no transitions, no pause).
-            Write(new[]
-            {
-                new GravographPass
-                {
-                    Polylines = polylines,
-                    FeedMmPerSec = Options.FeedMmPerSec,
-                    DepthInches = Options.DepthInches,
-                    PauseBefore = false,
-                    PauseMessage = "",
-                },
-            }, output);
-        }
-
-        /// <summary>
-        /// Writes the full byte stream for an ordered list of tool passes. The preamble
-        /// carries the first pass's feed/depth; each later pass emits an inline feed
-        /// (and depth, if changed) and, when <see cref="GravographPass.PauseBefore"/> is
-        /// set, parks to the operator origin and emits an operator pause before cutting.
-        /// </summary>
-        public void Write(IReadOnlyList<GravographPass> passes, Stream output)
-        {
-            if (passes == null) throw new ArgumentNullException(nameof(passes));
             if (output == null) throw new ArgumentNullException(nameof(output));
 
-            var firstFeed = passes.Count > 0 ? passes[0].FeedMmPerSec : Options.FeedMmPerSec;
-            var firstDepth = passes.Count > 0 ? passes[0].DepthInches : Options.DepthInches;
-
             var preamble = (byte[])PreambleTemplate.Clone();
-            PatchOperand(preamble, (byte)'V', (byte)'S', (short)firstFeed);
+            PatchOperand(preamble, (byte)'V', (byte)'S', (short)Options.FeedMmPerSec);
-            PatchOperand(preamble, (byte)'V', (byte)'Z', (short)firstFeed);
+            PatchOperand(preamble, (byte)'V', (byte)'Z', (short)Options.FeedMmPerSec);
-            PatchOperand(preamble, (byte)'D', (byte)'Z', DepthInStepsAsInt16(firstDepth));
+            PatchOperand(preamble, (byte)'D', (byte)'Z', DepthInStepsAsInt16());
             output.Write(preamble, 0, preamble.Length);
 
             // Cumulative head position from the operator-set upper-left origin, in
@@ -153,67 +105,13 @@ namespace OpenNest.Posts.GravographIS
 
             var firstPolyline = true;
             var polyIndex = 0;
-            var currentFeed = firstFeed;
-            var currentDepth = firstDepth;
 
-            for (var p = 0; p < passes.Count; p++)
+            foreach (var poly in polylines)
-            {
-                var pass = passes[p];
-
-                if (p > 0)
-                {
-                    if (pass.PauseBefore)
-                    {
-                        // Park: lift Z, then rapid (pen-up) back to the operator origin so
-                        // the head is clear of the work while the tool is swapped.
-                        WriteLiftOnly(output);
-                        WriteTravel(output, (byte)'P', (byte)'U',
-                            checked(-headX), checked(-headY),
-                            ref headX, ref headY, envelopeXSteps, envelopeYSteps, polyIndex);
-                        WritePauseCore(output, pass.PauseMessage);
-                    }
-
-                    if (pass.FeedMmPerSec != currentFeed)
-                    {
-                        WriteCommand(output, (byte)'V', (byte)'S', (short)pass.FeedMmPerSec);
-                        WriteCommand(output, (byte)'V', (byte)'Z', (short)pass.FeedMmPerSec);
-                        currentFeed = pass.FeedMmPerSec;
-                    }
-
-                    if (pass.DepthInches != currentDepth)
-                    {
-                        WriteCommand(output, (byte)'D', (byte)'Z', DepthInStepsAsInt16(pass.DepthInches));
-                        currentDepth = pass.DepthInches;
-                    }
-                }
-
-                if (pass.Polylines == null) continue;
-
-                foreach (var poly in pass.Polylines)
             {
                 polyIndex++;
                 if (poly == null || poly.Count < 2)
                     continue;
 
-                    WritePolyline(output, poly, ref firstPolyline, ref headX, ref headY,
-                        envelopeXSteps, envelopeYSteps, polyIndex);
-                }
-            }
-
-            WriteLiftOnly(output);
-            if (Options.ReturnToOriginAtEnd && !firstPolyline)
-            {
-                WriteTravel(output, (byte)'P', (byte)'U',
-                    checked(-headX), checked(-headY),
-                    ref headX, ref headY, envelopeXSteps, envelopeYSteps, polyIndex);
-            }
-            output.Write(EndJobBytes, 0, EndJobBytes.Length);
-        }
-
-        private void WritePolyline(Stream output, IReadOnlyList<Vector> poly,
-            ref bool firstPolyline, ref int headX, ref int headY,
-            int envelopeXSteps, int envelopeYSteps, int polyIndex)
-        {
                 var (startX, startY) = ToWire(poly[0]);
                 WriteTravel(output,
                     firstPolyline ? (byte)'D' : (byte)'P',
@@ -248,49 +146,14 @@ namespace OpenNest.Posts.GravographIS
                 firstPolyline = false;
             }
 
-        // The operator pause, minus the leading lift/park which the caller emits.
+            WriteLiftOnly(output);
-        // Stops the spindle (MC off), turns off aux, writes the console message, then
+            if (Options.ReturnToOriginAtEnd && !firstPolyline)
-        // restarts the spindle (MC on) so the job resumes when the operator presses start.
-        private static void WritePauseCore(Stream s, string message)
             {
-            WriteCommandRaw(s, (byte)'M', (byte)'C', 0x00, 0x00); // motor off
+                WriteTravel(output, (byte)'P', (byte)'U',
-            WriteCommandRaw(s, (byte)'O', (byte)'U', 0xFF, 0xFB); // aux off
+                    checked(-headX), checked(-headY),
-            WriteCommandRaw(s, (byte)'O', (byte)'U', 0xFF, 0xFA); // aux off
+                    ref headX, ref headY, envelopeXSteps, envelopeYSteps, polyIndex);
-            WriteCommandRaw(s, (byte)'L', (byte)'B', 0x00, 0x00); // begin message
-            WriteMessagePackets(s, message);
-            WriteCommandRaw(s, (byte)'N', (byte)'R', 0x00, 0x01); // line terminator
-            WriteCommandRaw(s, (byte)'L', (byte)'B', 0x00, 0x01); // end message
-            WriteCommandRaw(s, (byte)'M', (byte)'C', 0x00, 0x01); // motor on
             }
-
+            output.Write(EndJobBytes, 0, EndJobBytes.Length);
-        // Console label packets carry two ASCII chars each; an odd-length message is
-        // space-padded to a whole number of packets so widths stay 2 bytes.
-        private static void WriteMessagePackets(Stream s, string message)
-        {
-            if (string.IsNullOrEmpty(message)) return;
-
-            var chars = Encoding.ASCII.GetBytes(message);
-            for (var i = 0; i < chars.Length; i += 2)
-            {
-                var c0 = chars[i];
-                var c1 = (i + 1 < chars.Length) ? chars[i + 1] : (byte)0x20;
-                WriteCommandRaw(s, (byte)'L', (byte)'B', c0, c1);
-            }
-        }
-
-        private static void WriteCommand(Stream s, byte c0, byte c1, short value)
-        {
-            WriteCommandRaw(s, c0, c1, (byte)((value >> 8) & 0xFF), (byte)(value & 0xFF));
-        }
-
-        private static void WriteCommandRaw(Stream s, byte c0, byte c1, byte hi, byte lo)
-        {
-            s.WriteByte(0xFF);
-            s.WriteByte(0xFD);
-            s.WriteByte(c0);
-            s.WriteByte(c1);
-            s.WriteByte(hi);
-            s.WriteByte(lo);
         }
 
         private const double StepsPerMm = 80.0;
@@ -318,11 +181,11 @@ namespace OpenNest.Posts.GravographIS
                 $"work envelope from upper-left origin. Refusing to emit the record.");
         }
 
-        private static short DepthInStepsAsInt16(double depthInches)
+        private short DepthInStepsAsInt16()
         {
-            var steps = (long)System.Math.Round(depthInches * StepsPerInch, MidpointRounding.AwayFromZero);
+            var steps = (long)System.Math.Round(Options.DepthInches * StepsPerInch, MidpointRounding.AwayFromZero);
             if (steps < short.MinValue || steps > short.MaxValue)
-                throw new ArgumentOutOfRangeException(nameof(depthInches), $"Depth {depthInches} in. → {steps} steps overflows int16.");
+                throw new ArgumentOutOfRangeException(nameof(Options.DepthInches), $"Depth {Options.DepthInches} in. → {steps} steps overflows int16.");
             return (short)steps;
         }
 

OpenNest.Posts.GravographIS/NestPolylineExtractor.cs

@@ -1,35 +1,15 @@
 using System;
 using System.Collections.Generic;
-using System.Linq;
 using OpenNest.CNC;
 using OpenNest.Geometry;
 
 namespace OpenNest.Posts.GravographIS
 {
-    /// <summary>
-    /// A polyline together with the <see cref="LayerType"/> of the moves that
-    /// produced it. The Gravograph post groups by layer to emit separate engrave
-    /// and cut passes (with a tool-change pause between them).
-    /// </summary>
-    public sealed class LayeredPolyline
-    {
-        public LayeredPolyline(List<Vector> points, LayerType layer)
-        {
-            Points = points;
-            Layer = layer;
-        }
-
-        public List<Vector> Points { get; }
-
-        public LayerType Layer { get; }
-    }
-
     /// <summary>
     /// Lifts polylines out of an OpenNest <see cref="Nest"/> for the Gravograph
     /// backend. Walks each <see cref="Part"/>'s <see cref="Program"/>, breaks
-    /// polylines at rapid moves and at <see cref="LayerType"/> changes, and
+    /// polylines at rapid moves, and tessellates arcs to a chord-deviation
-    /// tessellates arcs to a chord-deviation tolerance (the wire format takes
+    /// tolerance (the wire format takes line segments only).
-    /// line segments only).
     /// </summary>
     public sealed class NestPolylineExtractor
     {
@@ -37,31 +17,13 @@ namespace OpenNest.Posts.GravographIS
 
         /// <summary>
         /// Extracts polylines from every non-cutoff part in every plate of the nest,
-        /// returning them in plate coordinates (inches). Layer information is dropped;
+        /// returning them in plate coordinates (inches).
-        /// use <see cref="ExtractLayered(Nest)"/> to keep it.
         /// </summary>
         public List<List<Vector>> Extract(Nest nest)
-        {
-            return ExtractLayered(nest).Select(p => p.Points).ToList();
-        }
-
-        /// <summary>
-        /// Extracts polylines for a single part without layer information.
-        /// </summary>
-        public List<List<Vector>> ExtractPart(Part part)
-        {
-            return ExtractPartLayered(part).Select(p => p.Points).ToList();
-        }
-
-        /// <summary>
-        /// Extracts layer-tagged polylines from every non-cutoff part in every plate,
-        /// in plate coordinates (inches). Each polyline is layer-uniform.
-        /// </summary>
-        public List<LayeredPolyline> ExtractLayered(Nest nest)
         {
             if (nest == null) throw new ArgumentNullException(nameof(nest));
 
-            var result = new List<LayeredPolyline>();
+            var result = new List<List<Vector>>();
 
             foreach (var plate in nest.Plates)
             {
@@ -78,17 +40,17 @@ namespace OpenNest.Posts.GravographIS
         }
 
         /// <summary>
-        /// Extracts layer-tagged polylines for a single part. Public so callers
+        /// Extracts polylines for a single part. Public so callers driving the
-        /// driving the writer directly (e.g. from a console one-off) can use it.
+        /// writer directly (e.g. from a console one-off) can use it.
         /// </summary>
-        public List<LayeredPolyline> ExtractPartLayered(Part part)
+        public List<List<Vector>> ExtractPart(Part part)
         {
-            var list = new List<LayeredPolyline>();
+            var list = new List<List<Vector>>();
             ExtractPart(part, list);
             return list;
         }
 
-        private void ExtractPart(Part part, List<LayeredPolyline> sink)
+        private void ExtractPart(Part part, List<List<Vector>> sink)
         {
             var program = part.Program;
             if (program == null) return;
@@ -105,7 +67,6 @@ namespace OpenNest.Posts.GravographIS
             var offset = part.Location;
             var pos = new Vector(0, 0);
             List<Vector> current = null;
-            var currentLayer = LayerType.Cut;
 
             foreach (var code in program.Codes)
             {
@@ -116,14 +77,17 @@ namespace OpenNest.Posts.GravographIS
                 {
                     case RapidMove rapid:
                     {
-                        FlushCurrent(sink, ref current, currentLayer);
+                        FlushCurrent(sink, ref current);
                         pos = rapid.EndPoint;
                         break;
                     }
 
                     case LinearMove linear:
                     {
-                        StartOrSplit(sink, ref current, ref currentLayer, linear.Layer, pos + offset);
+                        if (current == null)
+                        {
+                            current = new List<Vector> { pos + offset };
+                        }
                         var end = linear.EndPoint;
                         current.Add(end + offset);
                         pos = end;
@@ -132,7 +96,10 @@ namespace OpenNest.Posts.GravographIS
 
                     case ArcMove arc:
                     {
-                        StartOrSplit(sink, ref current, ref currentLayer, arc.Layer, pos + offset);
+                        if (current == null)
+                        {
+                            current = new List<Vector> { pos + offset };
+                        }
                         TessellateArc(pos, arc, offset, ArcChordToleranceInches, current);
                         pos = arc.EndPoint;
                         break;
@@ -140,33 +107,13 @@ namespace OpenNest.Posts.GravographIS
                 }
             }
 
-            FlushCurrent(sink, ref current, currentLayer);
+            FlushCurrent(sink, ref current);
         }
 
-        // Ensures `current` is an open polyline whose layer matches `moveLayer`,
+        private static void FlushCurrent(List<List<Vector>> sink, ref List<Vector> current)
-        // seeded at `seed` (the current pen position). When the layer changes
-        // mid-chain the previous polyline is flushed and a new one begins at the
-        // shared seam vertex so engrave and cut passes stay geometrically continuous.
-        private static void StartOrSplit(List<LayeredPolyline> sink, ref List<Vector> current,
-            ref LayerType currentLayer, LayerType moveLayer, Vector seed)
-        {
-            if (current == null)
-            {
-                current = new List<Vector> { seed };
-                currentLayer = moveLayer;
-            }
-            else if (moveLayer != currentLayer)
-            {
-                FlushCurrent(sink, ref current, currentLayer);
-                current = new List<Vector> { seed };
-                currentLayer = moveLayer;
-            }
-        }
-
-        private static void FlushCurrent(List<LayeredPolyline> sink, ref List<Vector> current, LayerType layer)
         {
             if (current != null && current.Count >= 2)
-                sink.Add(new LayeredPolyline(current, layer));
+                sink.Add(current);
             current = null;
         }
 

OpenNest.Tests/Converters/ConvertGeometryLayerTests.cs

@@ -1,70 +0,0 @@
-using System.Linq;
-using OpenNest.CNC;
-using OpenNest.Converters;
-using OpenNest.Geometry;
-
-namespace OpenNest.Tests.Converters;
-
-public class ConvertGeometryLayerTests
-{
-    private static Program ProgramFor(Entity entity)
-    {
-        var shape = new Shape();
-        shape.Entities.Add(entity);
-        return ConvertGeometry.ToProgram(shape);
-    }
-
-    [Fact]
-    public void AddLine_EngraveLayer_TagsScribe()
-    {
-        var line = new Line(0, 0, 1, 0) { Layer = new Layer("ENGRAVE") };
-
-        var pgm = ProgramFor(line);
-
-        Assert.All(pgm.Codes.OfType<LinearMove>(), m => Assert.Equal(LayerType.Scribe, m.Layer));
-    }
-
-    [Fact]
-    public void AddLine_EtchLayer_TagsScribe()
-    {
-        var line = new Line(0, 0, 1, 0) { Layer = new Layer("etch") };
-
-        var pgm = ProgramFor(line);
-
-        Assert.All(pgm.Codes.OfType<LinearMove>(), m => Assert.Equal(LayerType.Scribe, m.Layer));
-    }
-
-    [Fact]
-    public void AddArc_EngraveLayer_TagsScribe()
-    {
-        var arc = new Arc(new Vector(0, 0), 1, 0, System.Math.PI / 2) { Layer = new Layer("ENGRAVE") };
-
-        var pgm = ProgramFor(arc);
-
-        var arcs = pgm.Codes.OfType<ArcMove>().ToList();
-        Assert.NotEmpty(arcs);
-        Assert.All(arcs, m => Assert.Equal(LayerType.Scribe, m.Layer));
-    }
-
-    [Fact]
-    public void AddCircle_EngraveLayer_TagsScribe()
-    {
-        var circle = new Circle(0, 0, 1) { Layer = new Layer("ENGRAVE") };
-
-        var pgm = ProgramFor(circle);
-
-        var arcs = pgm.Codes.OfType<ArcMove>().ToList();
-        Assert.NotEmpty(arcs);
-        Assert.All(arcs, m => Assert.Equal(LayerType.Scribe, m.Layer));
-    }
-
-    [Fact]
-    public void AddLine_DefaultLayer_StaysCut()
-    {
-        var line = new Line(0, 0, 1, 0) { Layer = new Layer("0") };
-
-        var pgm = ProgramFor(line);
-
-        Assert.All(pgm.Codes.OfType<LinearMove>(), m => Assert.Equal(LayerType.Cut, m.Layer));
-    }
-}

OpenNest.Tests/Geometry/GeometrySimplifierTests.cs

@@ -131,111 +131,6 @@ public class GeometrySimplifierTests
         Assert.IsType<Arc>(result.Entities[6]);
     }
 
-    [Fact]
-    public void Analyze_FilletBetweenTangentLines_ArcIsTangentToLines()
-    {
-        // A 90-degree fillet (r=0.3, center origin, 270deg..360deg CCW) between two
-        // long tangent lines, approximated by 8 chords whose interior vertices bulge
-        // radially outward within tolerance (simulates real DXF tessellation noise).
-        var r = 0.3;
-        var deltas = new[] { 0.0, 0.002, 0.003, 0.0035, 0.0035, 0.0035, 0.003, 0.002, 0.0 };
-        var pts = new List<Vector>();
-        for (var i = 0; i <= 8; i++)
-        {
-            var ang = OpenNest.Math.Angle.ToRadians(270 + 11.25 * i);
-            var radius = r + deltas[i];
-            pts.Add(new Vector(radius * System.Math.Cos(ang), radius * System.Math.Sin(ang)));
-        }
-
-        var shape = new Shape();
-        shape.Entities.Add(new Line(new Vector(-2, -r), pts[0]));
-        for (var i = 0; i < pts.Count - 1; i++)
-            shape.Entities.Add(new Line(pts[i], pts[i + 1]));
-        shape.Entities.Add(new Line(pts[^1], new Vector(r, 2)));
-
-        var simplifier = new GeometrySimplifier { Tolerance = 0.004 };
-        var candidates = simplifier.Analyze(shape);
-
-        Assert.Single(candidates);
-        var arc = candidates[0].FittedArc;
-
-        // Arc must pass exactly through the run's boundary vertices (no gaps)
-        Assert.True(arc.StartPoint().DistanceTo(pts[0]) < 1e-6);
-        Assert.True(arc.EndPoint().DistanceTo(pts[^1]) < 1e-6);
-
-        // Arc must be tangent to the adjacent straight edges at its endpoints
-        var startDelta = AngleBetweenDeg(ArcTangentAt(arc, arc.StartPoint()), new Vector(1, 0));
-        var endDelta = AngleBetweenDeg(ArcTangentAt(arc, arc.EndPoint()), new Vector(0, 1));
-        Assert.True(startDelta < 0.3, $"Arc start not tangent to incoming line: off by {startDelta:F3} deg");
-        Assert.True(endDelta < 0.3, $"Arc end not tangent to outgoing line: off by {endDelta:F3} deg");
-    }
-
-    [Fact]
-    public void Analyze_CompoundCurve_AdjacentArcsAreTangentAtJunction()
-    {
-        // Two tangent-continuous arcs of different radii (r=0.2 sweeping 60deg, then
-        // r=0.6 sweeping 40deg), tessellated into chords with slight radial noise.
-        // The fitted arcs must stay tangent-continuous at their junction.
-        var c1 = new Vector(0, 0);
-        var r1 = 0.2;
-        var deltas1 = new[] { 0.0, 0.001, 0.0005, -0.0005, -0.001, -0.0005, 0.0 };
-        var pts = new List<Vector>();
-        for (var i = 0; i <= 6; i++)
-        {
-            var ang = OpenNest.Math.Angle.ToRadians(10 * i);
-            var radius = r1 + deltas1[i];
-            pts.Add(new Vector(c1.X + radius * System.Math.Cos(ang), c1.Y + radius * System.Math.Sin(ang)));
-        }
-
-        // Second arc center along the junction radius so tangents match at the junction
-        var junctionAngle = OpenNest.Math.Angle.ToRadians(60);
-        var u = new Vector(System.Math.Cos(junctionAngle), System.Math.Sin(junctionAngle));
-        var r2 = 0.6;
-        var c2 = new Vector(c1.X + u.X * (r1 - r2), c1.Y + u.Y * (r1 - r2));
-        var deltas2 = new[] { 0.0, 0.001, -0.001, 0.0005, -0.0005, 0.0 };
-        for (var i = 1; i <= 5; i++)
-        {
-            var ang = OpenNest.Math.Angle.ToRadians(60 + 8 * i);
-            var radius = r2 + deltas2[i];
-            pts.Add(new Vector(c2.X + radius * System.Math.Cos(ang), c2.Y + radius * System.Math.Sin(ang)));
-        }
-
-        var shape = new Shape();
-        for (var i = 0; i < pts.Count - 1; i++)
-            shape.Entities.Add(new Line(pts[i], pts[i + 1]));
-
-        var simplifier = new GeometrySimplifier { Tolerance = 0.004 };
-        var candidates = simplifier.Analyze(shape);
-
-        Assert.Equal(2, candidates.Count);
-        var arcA = candidates[0].FittedArc;
-        var arcB = candidates[1].FittedArc;
-
-        // Arcs must share the junction vertex exactly
-        Assert.True(arcA.EndPoint().DistanceTo(arcB.StartPoint()) < 1e-6);
-
-        // Tangent continuity across the junction
-        var junctionDelta = AngleBetweenDeg(ArcTangentAt(arcA, arcA.EndPoint()), ArcTangentAt(arcB, arcB.StartPoint()));
-        Assert.True(junctionDelta < 0.3, $"Tangent break of {junctionDelta:F3} deg at arc-arc junction");
-    }
-
-    private static Vector ArcTangentAt(Arc arc, Vector pt)
-    {
-        var ang = System.Math.Atan2(pt.Y - arc.Center.Y, pt.X - arc.Center.X);
-        return arc.IsReversed
-            ? new Vector(System.Math.Sin(ang), -System.Math.Cos(ang))
-            : new Vector(-System.Math.Sin(ang), System.Math.Cos(ang));
-    }
-
-    private static double AngleBetweenDeg(Vector v1, Vector v2)
-    {
-        var l1 = System.Math.Sqrt(v1.X * v1.X + v1.Y * v1.Y);
-        var l2 = System.Math.Sqrt(v2.X * v2.X + v2.Y * v2.Y);
-        var dot = (v1.X * v2.X + v1.Y * v2.Y) / (l1 * l2);
-        dot = System.Math.Max(-1, System.Math.Min(1, dot));
-        return System.Math.Acos(dot) * 180.0 / System.Math.PI;
-    }
-
     [Fact]
     public void Apply_DynaPanDxf_NoGapsAfterSimplification()
     {

OpenNest.Tests/GravographIS/GravographISPostConfigTests.cs

@@ -1,51 +0,0 @@
-using OpenNest.CNC;
-using OpenNest.Posts.GravographIS;
-
-namespace OpenNest.Tests.GravographIS;
-
-public class GravographISPostConfigTests
-{
-    [Fact]
-    public void Defaults_EngraveBlock_NoPause_FasterFeed()
-    {
-        var config = new GravographISPostConfig();
-
-        Assert.Equal(10, config.Engrave.FeedMmPerSec);
-        Assert.False(config.Engrave.PauseBefore);
-    }
-
-    [Fact]
-    public void Defaults_CutBlock_PausesToChangeTool()
-    {
-        var config = new GravographISPostConfig();
-
-        Assert.Equal(3, config.Cut.FeedMmPerSec);
-        Assert.True(config.Cut.PauseBefore);
-        Assert.Equal("Change tool", config.Cut.PauseMessage);
-    }
-
-    [Theory]
-    [InlineData(LayerType.Scribe)]
-    public void ConfigFor_Scribe_ReturnsEngraveBlock(LayerType layer)
-    {
-        var config = new GravographISPostConfig();
-        Assert.Same(config.Engrave, config.ConfigFor(layer));
-    }
-
-    [Theory]
-    [InlineData(LayerType.Cut)]
-    [InlineData(LayerType.Leadin)]
-    [InlineData(LayerType.Leadout)]
-    public void ConfigFor_CutLayers_ReturnCutBlock(LayerType layer)
-    {
-        var config = new GravographISPostConfig();
-        Assert.Same(config.Cut, config.ConfigFor(layer));
-    }
-
-    [Fact]
-    public void ConfigFor_Display_ReturnsNull_SoItIsSkipped()
-    {
-        var config = new GravographISPostConfig();
-        Assert.Null(config.ConfigFor(LayerType.Display));
-    }
-}

OpenNest.Tests/GravographIS/GravographISPostProcessorTests.cs

@@ -1,70 +0,0 @@
-using System.Collections.Generic;
-using OpenNest.CNC;
-using OpenNest.Geometry;
-using OpenNest.Posts.GravographIS;
-
-namespace OpenNest.Tests.GravographIS;
-
-public class GravographISPostProcessorTests
-{
-    private static LayeredPolyline Poly(LayerType layer, params Vector[] pts)
-        => new LayeredPolyline(new List<Vector>(pts), layer);
-
-    [Fact]
-    public void BuildPasses_EngraveAndCut_OrdersEngraveFirstThenCutWithPause()
-    {
-        var post = new GravographISPostProcessor();
-
-        var passes = post.BuildPasses(new[]
-        {
-            Poly(LayerType.Cut, new Vector(0, 0), new Vector(1, 0)),
-            Poly(LayerType.Scribe, new Vector(0, 0), new Vector(0, 1)),
-        });
-
-        Assert.Equal(2, passes.Count);
-
-        Assert.Equal(post.Config.Engrave.FeedMmPerSec, passes[0].FeedMmPerSec);
-        Assert.False(passes[0].PauseBefore);
-
-        Assert.Equal(post.Config.Cut.FeedMmPerSec, passes[1].FeedMmPerSec);
-        Assert.True(passes[1].PauseBefore);
-        Assert.Equal("Change tool", passes[1].PauseMessage);
-    }
-
-    [Fact]
-    public void BuildPasses_CutOnly_IsSinglePass()
-    {
-        var post = new GravographISPostProcessor();
-
-        var passes = post.BuildPasses(new[]
-        {
-            Poly(LayerType.Cut, new Vector(0, 0), new Vector(1, 0)),
-        });
-
-        Assert.Single(passes);
-        Assert.Equal(post.Config.Cut.FeedMmPerSec, passes[0].FeedMmPerSec);
-    }
-
-    [Fact]
-    public void BuildPasses_SkipsDisplayGeometry()
-    {
-        var post = new GravographISPostProcessor();
-
-        var passes = post.BuildPasses(new[]
-        {
-            Poly(LayerType.Display, new Vector(0, 0), new Vector(1, 0)),
-            Poly(LayerType.Cut, new Vector(0, 0), new Vector(0, 1)),
-        });
-
-        Assert.Single(passes);
-        Assert.Equal(post.Config.Cut.FeedMmPerSec, passes[0].FeedMmPerSec);
-    }
-
-    [Fact]
-    public void Config_IsExposedThroughConfigurableInterface()
-    {
-        var post = new GravographISPostProcessor(new GravographISPostConfig());
-        OpenNest.IConfigurablePostProcessor configurable = post;
-        Assert.Same(post.Config, configurable.Config);
-    }
-}

OpenNest.Tests/GravographIS/GravographISWriterTests.cs

@@ -178,101 +178,6 @@ public class GravographISWriterTests
         Assert.Equal(-GravographISWriter.StepsPerInch, dy);
     }
 
-    [Fact]
-    public void Passes_PauseBeforeCut_EmitsPauseSequenceBetweenGroups()
-    {
-        var engrave = new List<IReadOnlyList<Vector>> { new[] { new Vector(0, 0), new Vector(1, 0) } };
-        var cut = new List<IReadOnlyList<Vector>> { new[] { new Vector(0, 0), new Vector(0, -1) } };
-        var passes = new List<GravographPass>
-        {
-            new GravographPass { Polylines = engrave, FeedMmPerSec = 10, DepthInches = 0.25 },
-            new GravographPass { Polylines = cut, FeedMmPerSec = 3, DepthInches = 0.25, PauseBefore = true, PauseMessage = "Hi" },
-        };
-
-        using var ms = new MemoryStream();
-        new GravographISWriter(new GravographISWriterOptions
-        {
-            EnvelopeGuardEnabled = false,
-            ReturnToOriginAtEnd = false,
-        }).Write(passes, ms);
-        var bytes = ms.ToArray();
-
-        var mcOff = IndexOf(bytes, 0, (byte)'M', (byte)'C', 0x00, 0x00);
-        var ouFb = IndexOf(bytes, mcOff, (byte)'O', (byte)'U', 0xFF, 0xFB);
-        var ouFa = IndexOf(bytes, ouFb, (byte)'O', (byte)'U', 0xFF, 0xFA);
-        var lbBegin = IndexOf(bytes, ouFa, (byte)'L', (byte)'B', 0x00, 0x00);
-        var lbMsg = IndexOf(bytes, lbBegin, (byte)'L', (byte)'B', (byte)'H', (byte)'i');
-        var nr = IndexOf(bytes, lbMsg, (byte)'N', (byte)'R', 0x00, 0x01);
-        var lbEnd = IndexOf(bytes, nr, (byte)'L', (byte)'B', 0x00, 0x01);
-        var mcOn = IndexOf(bytes, lbEnd, (byte)'M', (byte)'C', 0x00, 0x01);
-
-        Assert.True(mcOff >= 0, "motor-off (MC 0000) not found");
-        Assert.True(mcOff < ouFb && ouFb < ouFa && ouFa < lbBegin && lbBegin < lbMsg
-            && lbMsg < nr && nr < lbEnd && lbEnd < mcOn,
-            "pause commands out of order");
-
-        // Resume sets the cut feed inline (VS 0x0003) after the motor restarts.
-        var vsCut = IndexOf(bytes, mcOn, (byte)'V', (byte)'S', 0x00, 0x03);
-        Assert.True(vsCut > mcOn, "cut feed not set after resume");
-    }
-
-    [Fact]
-    public void Passes_PauseOddMessage_SpacePadsLastPacket()
-    {
-        var passes = new List<GravographPass>
-        {
-            new GravographPass { Polylines = new List<IReadOnlyList<Vector>> { new[] { new Vector(0, 0), new Vector(1, 0) } }, FeedMmPerSec = 10 },
-            new GravographPass { Polylines = new List<IReadOnlyList<Vector>> { new[] { new Vector(0, 0), new Vector(0, -1) } }, FeedMmPerSec = 3, PauseBefore = true, PauseMessage = "abc" },
-        };
-
-        using var ms = new MemoryStream();
-        new GravographISWriter(new GravographISWriterOptions { EnvelopeGuardEnabled = false, ReturnToOriginAtEnd = false }).Write(passes, ms);
-        var bytes = ms.ToArray();
-
-        var lbAb = IndexOf(bytes, 0, (byte)'L', (byte)'B', (byte)'a', (byte)'b');
-        var lbCPad = IndexOf(bytes, lbAb, (byte)'L', (byte)'B', (byte)'c', 0x20);
-        Assert.True(lbAb >= 0, "first message packet 'ab' not found");
-        Assert.True(lbCPad > lbAb, "odd packet not space-padded to 'c '");
-    }
-
-    [Fact]
-    public void Passes_DifferentFeeds_NoPause_EmitsInlineFeedChangeNoMessage()
-    {
-        var passes = new List<GravographPass>
-        {
-            new GravographPass { Polylines = new List<IReadOnlyList<Vector>> { new[] { new Vector(0, 0), new Vector(1, 0) } }, FeedMmPerSec = 10 },
-            new GravographPass { Polylines = new List<IReadOnlyList<Vector>> { new[] { new Vector(0, 0), new Vector(0, -1) } }, FeedMmPerSec = 3, PauseBefore = false },
-        };
-
-        using var ms = new MemoryStream();
-        new GravographISWriter(new GravographISWriterOptions { EnvelopeGuardEnabled = false, ReturnToOriginAtEnd = false }).Write(passes, ms);
-        var bytes = ms.ToArray();
-
-        Assert.True(IndexOf(bytes, 0, (byte)'V', (byte)'S', 0x00, 0x03) >= 0, "inline cut feed change missing");
-        Assert.True(IndexOfCmd(bytes, (byte)'L', (byte)'B') < 0, "no LB message expected without a pause");
-    }
-
-    private static int IndexOf(byte[] bytes, int from, byte c0, byte c1, byte hi, byte lo)
-    {
-        for (var i = System.Math.Max(0, from); i <= bytes.Length - 6; i++)
-        {
-            if (bytes[i] == 0xFF && bytes[i + 1] == 0xFD && bytes[i + 2] == c0 &&
-                bytes[i + 3] == c1 && bytes[i + 4] == hi && bytes[i + 5] == lo)
-                return i;
-        }
-        return -1;
-    }
-
-    private static int IndexOfCmd(byte[] bytes, byte c0, byte c1)
-    {
-        for (var i = 0; i <= bytes.Length - 4; i++)
-        {
-            if (bytes[i] == 0xFF && bytes[i + 1] == 0xFD && bytes[i + 2] == c0 && bytes[i + 3] == c1)
-                return i;
-        }
-        return -1;
-    }
-
     private static void AssertOperand(byte[] bytes, byte c0, byte c1, byte hi, byte lo)
     {
         for (var i = 0; i < bytes.Length - 5; i++)

OpenNest.Tests/GravographIS/NestPolylineExtractorTests.cs

@@ -34,45 +34,4 @@ public class NestPolylineExtractorTests
         Assert.Equal(new Vector(0.25, 47.75), poly[3]);
         Assert.Equal(new Vector(0.25, 46.75), poly[4]);
     }
-
-    [Fact]
-    public void ExtractPartLayered_SplitsContinuousChainAtLayerChange()
-    {
-        // A single continuous chain (no rapid) that switches from Scribe to Cut
-        // must be split into two layer-uniform polylines sharing the seam vertex,
-        // so the post can emit a tool-change pause between engrave and cut.
-        var program = new Program(Mode.Absolute);
-        program.Codes.Add(new LinearMove(1, 0) { Layer = LayerType.Scribe });
-        program.Codes.Add(new LinearMove(2, 0) { Layer = LayerType.Scribe });
-        program.Codes.Add(new LinearMove(2, 1) { Layer = LayerType.Cut });
-        program.Codes.Add(new LinearMove(3, 1) { Layer = LayerType.Cut });
-
-        var drawing = new Drawing("Mixed", program);
-        var part = new Part(drawing, new Vector(0, 0));
-
-        var polylines = new NestPolylineExtractor().ExtractPartLayered(part);
-
-        Assert.Equal(2, polylines.Count);
-
-        Assert.Equal(LayerType.Scribe, polylines[0].Layer);
-        Assert.Equal(new[] { new Vector(0, 0), new Vector(1, 0), new Vector(2, 0) }, polylines[0].Points);
-
-        Assert.Equal(LayerType.Cut, polylines[1].Layer);
-        Assert.Equal(new[] { new Vector(2, 0), new Vector(2, 1), new Vector(3, 1) }, polylines[1].Points);
-    }
-
-    [Fact]
-    public void ExtractPartLayered_UniformChain_IsSinglePolyline()
-    {
-        var program = new Program(Mode.Absolute);
-        program.Codes.Add(new LinearMove(1, 0));
-        program.Codes.Add(new LinearMove(1, 1));
-
-        var part = new Part(new Drawing("Cut", program), new Vector(0, 0));
-
-        var polylines = new NestPolylineExtractor().ExtractPartLayered(part);
-
-        Assert.Single(polylines);
-        Assert.Equal(LayerType.Cut, polylines[0].Layer);
-    }
 }