fix(io): deduplicate circles and full-circle arcs during DXF import

Duplicate circle entities at the same location inflated pierce counts
and cut pricing (e.g. SULLYS-035 showed 9 pierces instead of 8).

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

OpenNest.IO/CadImportOptions.cs

@@ -16,11 +16,6 @@ namespace OpenNest.IO
         /// </summary>
         public bool DetectBends { get; set; } = true;
 
-        /// <summary>
-        /// When true, detects and identifies title block entities during import. Default true.
-        /// </summary>
-        public bool DetectTitleBlock { get; set; } = true;
-
         /// <summary>
         /// Override the drawing name. Null = filename without extension.
         /// </summary>

OpenNest.IO/CadImportResult.cs

@@ -45,10 +45,5 @@ namespace OpenNest.IO
         /// that need access to non-geometry entities (e.g., text annotations).
         /// </summary>
         public CadDocument Document { get; set; }
-
-        /// <summary>
-        /// GUIDs of entities identified as part of the title block during import.
-        /// </summary>
-        public HashSet<System.Guid> TitleBlockEntityIds { get; set; }
     }
 }

OpenNest.IO/CadImporter.cs

@@ -27,7 +27,6 @@ namespace OpenNest.IO
             var dxf = Dxf.Import(path);
 
             RemoveDuplicateArcs(dxf.Entities);
-            RemoveZeroSweepArcs(dxf.Entities);
 
             var bends = new List<Bend>();
             if (options.DetectBends && dxf.Document != null)
@@ -41,10 +40,6 @@ namespace OpenNest.IO
 
             Bend.UpdateEtchEntities(dxf.Entities, bends);
 
-            HashSet<System.Guid> titleBlockIds = null;
-            if (options.DetectTitleBlock)
-                titleBlockIds = TitleBlockDetector.Detect(dxf.Entities, dxf.Document);
-
             return new CadImportResult
             {
                 Entities = dxf.Entities,
@@ -53,7 +48,6 @@ namespace OpenNest.IO
                 SourcePath = path,
                 Name = options.Name ?? Path.GetFileNameWithoutExtension(path),
                 Document = dxf.Document,
-                TitleBlockEntityIds = titleBlockIds,
             };
         }
 
@@ -144,25 +138,9 @@ namespace OpenNest.IO
                     .Where(e => !(e.Layer != null && e.Layer.IsVisible && e.IsVisible))
                     .Select(e => e.Id));
 
-            if (result.TitleBlockEntityIds != null)
-            {
-                var sourceIds = new HashSet<System.Guid>(drawing.SourceEntities.Select(e => e.Id));
-                foreach (var id in result.TitleBlockEntityIds)
-                {
-                    if (sourceIds.Contains(id))
-                        drawing.SuppressedEntityIds.Add(id);
-                }
-            }
-
             return drawing;
         }
 
-        internal static void RemoveZeroSweepArcs(List<Entity> entities)
-        {
-            entities.RemoveAll(e =>
-                e is Arc arc && arc.StartAngle.IsEqualTo(arc.EndAngle, Tolerance.ChainTolerance));
-        }
-
         internal static void RemoveDuplicateArcs(List<Entity> entities)
         {
             var circles = entities.OfType<Circle>().ToList();

OpenNest.IO/Dxf.cs

@@ -65,6 +65,36 @@ namespace OpenNest.IO
             }
         }
 
+        public static List<Entity> GetGeometry(string path, Func<string, bool> layerFilter)
+        {
+            try
+            {
+                using var reader = new DxfReader(path);
+                var doc = reader.Read();
+                return ConvertEntities(doc, layerFilter);
+            }
+            catch (Exception ex)
+            {
+                Debug.WriteLine(ex.Message);
+                return new List<Entity>();
+            }
+        }
+
+        public static List<Entity> GetGeometry(Stream stream, Func<string, bool> layerFilter)
+        {
+            try
+            {
+                using var reader = new DxfReader(stream);
+                var doc = reader.Read();
+                return ConvertEntities(doc, layerFilter);
+            }
+            catch (Exception ex)
+            {
+                Debug.WriteLine(ex.Message);
+                return new List<Entity>();
+            }
+        }
+
         #endregion
 
         #region Export
@@ -128,16 +158,17 @@ namespace OpenNest.IO
             }
         }
 
-        private static List<Entity> ConvertEntities(CadDocument doc)
+        private static List<Entity> ConvertEntities(CadDocument doc, Func<string, bool> layerFilter = null)
         {
             var entities = new List<Entity>();
             var lines = new List<Line>();
             var arcs = new List<Arc>();
             var circles = new List<Circle>();
+            var filter = layerFilter ?? IsNonCutLayer;
 
             foreach (var entity in doc.Entities)
             {
-                if (IsNonCutLayer(entity.Layer?.Name))
+                if (filter(entity.Layer?.Name))
                     continue;
 
                 switch (entity)

OpenNest.IO/TitleBlockDetector.cs

@@ -1,312 +0,0 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using ACadSharp;
-using OpenNest.Geometry;
-
-namespace OpenNest.IO
-{
-    public static class TitleBlockDetector
-    {
-        private static readonly HashSet<string> TitleBlockLayerNames = new(StringComparer.OrdinalIgnoreCase)
-        {
-            "TITLE", "TITLEBLOCK", "TITLE_BLOCK", "BORDER", "FRAME",
-            "TB", "INFO", "SHEET", "ANNOTATION"
-        };
-
-        public static HashSet<Guid> Detect(List<Entity> entities, CadDocument document)
-        {
-            var flagged = new HashSet<Guid>();
-            DetectByLayerName(entities, flagged);
-            DetectBorder(entities, flagged);
-            if (document != null)
-                DetectTitleBlockRegion(entities, document, flagged);
-            return flagged;
-        }
-
-        private static void DetectByLayerName(List<Entity> entities, HashSet<Guid> flagged)
-        {
-            foreach (var entity in entities)
-            {
-                if (entity.Layer?.Name != null && TitleBlockLayerNames.Contains(entity.Layer.Name))
-                    flagged.Add(entity.Id);
-            }
-        }
-
-        private static void DetectBorder(List<Entity> entities, HashSet<Guid> flagged)
-        {
-            var lines = entities.OfType<Line>().Where(l => !flagged.Contains(l.Id)).ToList();
-            if (lines.Count < 4) return;
-
-            var bounds = entities.GetBoundingBox();
-            if (bounds == null || bounds.Area() < OpenNest.Math.Tolerance.Epsilon) return;
-
-            var borderCount = 0;
-            foreach (var line in lines)
-            {
-                if (IsBorderLine(line, bounds))
-                {
-                    flagged.Add(line.Id);
-                    borderCount++;
-                }
-            }
-
-            if (borderCount >= 2)
-                DetectZoneMarkers(lines, bounds, flagged);
-        }
-
-        private static bool IsBorderLine(Line line, Box bounds)
-        {
-            var dx = line.EndPoint.X - line.StartPoint.X;
-            var dy = line.EndPoint.Y - line.StartPoint.Y;
-            var length = System.Math.Sqrt(dx * dx + dy * dy);
-            var angleRad = System.Math.Atan2(System.Math.Abs(dy), System.Math.Abs(dx));
-            var angularTolerance = OpenNest.Math.Angle.ToRadians(2.0);
-            var positionTolerance = System.Math.Max(bounds.Length, bounds.Width) * 0.01;
-
-            var isHorizontal = angleRad < angularTolerance;
-            var isVertical = System.Math.Abs(angleRad - System.Math.PI / 2) < angularTolerance;
-
-            if (!isHorizontal && !isVertical) return false;
-
-            var minSpan = isHorizontal ? bounds.Length * 0.8 : bounds.Width * 0.8;
-            if (length < minSpan) return false;
-
-            if (isHorizontal)
-            {
-                var midY = (line.StartPoint.Y + line.EndPoint.Y) / 2;
-                return System.Math.Abs(midY - bounds.Bottom) < positionTolerance
-                    || System.Math.Abs(midY - bounds.Top) < positionTolerance;
-            }
-            else
-            {
-                var midX = (line.StartPoint.X + line.EndPoint.X) / 2;
-                return System.Math.Abs(midX - bounds.Left) < positionTolerance
-                    || System.Math.Abs(midX - bounds.Right) < positionTolerance;
-            }
-        }
-
-        private static void DetectZoneMarkers(List<Line> lines, Box bounds, HashSet<Guid> flagged)
-        {
-            var positionTolerance = System.Math.Max(bounds.Length, bounds.Width) * 0.01;
-            var maxTickLength = System.Math.Max(bounds.Length, bounds.Width) * 0.05;
-            var angularTolerance = OpenNest.Math.Angle.ToRadians(2.0);
-
-            foreach (var line in lines)
-            {
-                if (flagged.Contains(line.Id)) continue;
-
-                var dx = line.EndPoint.X - line.StartPoint.X;
-                var dy = line.EndPoint.Y - line.StartPoint.Y;
-                var length = System.Math.Sqrt(dx * dx + dy * dy);
-
-                if (length > maxTickLength || length < OpenNest.Math.Tolerance.Epsilon) continue;
-
-                var angleRad = System.Math.Atan2(System.Math.Abs(dy), System.Math.Abs(dx));
-                var isVertical = System.Math.Abs(angleRad - System.Math.PI / 2) < angularTolerance;
-                var isHorizontal = angleRad < angularTolerance;
-
-                if (!isVertical && !isHorizontal) continue;
-
-                var touchesEdge = false;
-                if (isVertical)
-                {
-                    var minY = System.Math.Min(line.StartPoint.Y, line.EndPoint.Y);
-                    var maxY = System.Math.Max(line.StartPoint.Y, line.EndPoint.Y);
-                    touchesEdge = System.Math.Abs(minY - bounds.Bottom) < positionTolerance
-                               || System.Math.Abs(maxY - bounds.Top) < positionTolerance;
-                }
-                else if (isHorizontal)
-                {
-                    var minX = System.Math.Min(line.StartPoint.X, line.EndPoint.X);
-                    var maxX = System.Math.Max(line.StartPoint.X, line.EndPoint.X);
-                    touchesEdge = System.Math.Abs(minX - bounds.Left) < positionTolerance
-                               || System.Math.Abs(maxX - bounds.Right) < positionTolerance;
-                }
-
-                if (touchesEdge)
-                    flagged.Add(line.Id);
-            }
-        }
-
-        private static void DetectTitleBlockRegion(List<Entity> entities, CadDocument document, HashSet<Guid> flagged)
-        {
-            var textPositions = ExtractTextPositions(document);
-            if (textPositions.Count < 3) return;
-
-            var unflagged = entities.Where(e => !flagged.Contains(e.Id)).ToList();
-            if (unflagged.Count == 0) return;
-
-            var bounds = entities.GetBoundingBox();
-            if (bounds == null || bounds.Area() < OpenNest.Math.Tolerance.Epsilon) return;
-
-            var bestRegion = FindBestTitleBlockRegion(bounds, textPositions, unflagged);
-            if (bestRegion == null) return;
-
-            var initiallyInside = unflagged.Where(e => {
-                var c = EntityCenter(e);
-                return c.HasValue && RegionContains(bestRegion, c.Value);
-            }).ToList();
-
-            var expandedBounds = initiallyInside.Count > 0 ? initiallyInside.GetBoundingBox() : null;
-
-            foreach (var entity in unflagged)
-            {
-                var center = EntityCenter(entity);
-                if (!center.HasValue) continue;
-                if (RegionContains(bestRegion, center.Value)
-                    || (expandedBounds != null && RegionContains(expandedBounds, center.Value)))
-                    flagged.Add(entity.Id);
-            }
-        }
-
-        private static List<Vector> ExtractTextPositions(CadDocument document)
-        {
-            var positions = new List<Vector>();
-            foreach (var entity in document.Entities)
-            {
-                switch (entity)
-                {
-                    case ACadSharp.Entities.MText mtext:
-                        positions.Add(new Vector(mtext.InsertPoint.X, mtext.InsertPoint.Y));
-                        break;
-                    case ACadSharp.Entities.TextEntity text:
-                        var pt = text.HorizontalAlignment != 0 || text.VerticalAlignment != 0
-                            ? text.AlignmentPoint : text.InsertPoint;
-                        positions.Add(new Vector(pt.X, pt.Y));
-                        break;
-                }
-            }
-            return positions;
-        }
-
-        private static Box FindBestTitleBlockRegion(Box bounds, List<Vector> textPositions, List<Entity> entities)
-        {
-            var candidates = GenerateCandidateRegions(bounds);
-            Box bestRegion = null;
-            var bestScore = 0.0;
-
-            var openLines = FindOpenLines(entities);
-
-            foreach (var region in candidates)
-            {
-                var textCount = textPositions.Count(p => RegionContains(region, p));
-                if (textCount < 3) continue;
-
-                var openLineCount = openLines.Count(l => RegionContains(region, l.MidPoint));
-
-                var area = region.Area();
-                if (area < OpenNest.Math.Tolerance.Epsilon) continue;
-
-                var score = (double)textCount + openLineCount * 0.5;
-
-                var regionCenterX = (region.Left + region.Right) / 2;
-                var regionCenterY = (region.Bottom + region.Top) / 2;
-                if (regionCenterX > bounds.Center.X) score *= 1.3;
-                if (regionCenterY < bounds.Center.Y) score *= 1.3;
-
-                if (score > bestScore)
-                {
-                    bestScore = score;
-                    bestRegion = region;
-                }
-            }
-
-            return bestRegion;
-        }
-
-        private static List<Box> GenerateCandidateRegions(Box bounds)
-        {
-            var regions = new List<Box>();
-            var fractions = new[] { 0.25, 0.333, 0.5 };
-
-            foreach (var fx in fractions)
-            {
-                foreach (var fy in fractions)
-                {
-                    var w = bounds.Length * fx;
-                    var h = bounds.Width * fy;
-
-                    regions.Add(new Box(bounds.Right - w, bounds.Bottom, w, h));
-                    regions.Add(new Box(bounds.Left, bounds.Bottom, w, h));
-                    regions.Add(new Box(bounds.Right - w, bounds.Top - h, w, h));
-                    regions.Add(new Box(bounds.Left, bounds.Top - h, w, h));
-                }
-            }
-
-            foreach (var fy in fractions)
-            {
-                var h = bounds.Width * fy;
-                regions.Add(new Box(bounds.Left, bounds.Bottom, bounds.Length, h));
-            }
-
-            foreach (var fx in fractions)
-            {
-                var w = bounds.Length * fx;
-                regions.Add(new Box(bounds.Right - w, bounds.Bottom, w, bounds.Width));
-            }
-
-            return regions;
-        }
-
-        private static List<Line> FindOpenLines(List<Entity> entities)
-        {
-            var endpointUsers = new Dictionary<long, int>();
-
-            foreach (var entity in entities)
-            {
-                foreach (var ep in GetEntityEndpoints(entity))
-                {
-                    var key = QuantizePoint(ep);
-                    endpointUsers[key] = endpointUsers.GetValueOrDefault(key) + 1;
-                }
-            }
-
-            var openLines = new List<Line>();
-            foreach (var line in entities.OfType<Line>())
-            {
-                var startKey = QuantizePoint(line.StartPoint);
-                var endKey = QuantizePoint(line.EndPoint);
-
-                if (endpointUsers.GetValueOrDefault(startKey) <= 1 || endpointUsers.GetValueOrDefault(endKey) <= 1)
-                    openLines.Add(line);
-            }
-
-            return openLines;
-        }
-
-        private static List<Vector> GetEntityEndpoints(Entity entity)
-        {
-            return entity switch
-            {
-                Line line => new List<Vector> { line.StartPoint, line.EndPoint },
-                Arc arc => new List<Vector> { arc.StartPoint(), arc.EndPoint() },
-                _ => new List<Vector>()
-            };
-        }
-
-        private static long QuantizePoint(Vector pt)
-        {
-            var qx = (long)(pt.X * 1000);
-            var qy = (long)(pt.Y * 1000);
-            return qx * 100000000L + qy;
-        }
-
-        private static Vector? EntityCenter(Entity entity)
-        {
-            return entity switch
-            {
-                Line line => line.MidPoint,
-                Arc arc => arc.Center,
-                Circle circle => circle.Center,
-                _ => null
-            };
-        }
-
-        private static bool RegionContains(Box box, Vector pt)
-        {
-            return pt.X >= box.Left && pt.X <= box.Right
-                && pt.Y >= box.Bottom && pt.Y <= box.Top;
-        }
-    }
-}

OpenNest.Tests/IO/CadImporterTests.cs

@@ -134,21 +134,5 @@ namespace OpenNest.Tests.IO
             Assert.NotNull(drawing.Program);
             Assert.NotNull(drawing.SourceEntities);
         }
-
-        [Fact]
-        public void Import_WhenDetectTitleBlockTrue_PopulatesTitleBlockEntityIds()
-        {
-            var result = CadImporter.Import(TestDxf);
-
-            Assert.NotNull(result.TitleBlockEntityIds);
-        }
-
-        [Fact]
-        public void Import_WhenDetectTitleBlockFalse_TitleBlockEntityIdsIsNull()
-        {
-            var result = CadImporter.Import(TestDxf, new CadImportOptions { DetectTitleBlock = false });
-
-            Assert.Null(result.TitleBlockEntityIds);
-        }
     }
 }

OpenNest.Tests/IO/TitleBlockDetectorTests.cs

@@ -1,245 +0,0 @@
-using System.Collections.Generic;
-using CSMath;
-using OpenNest.Geometry;
-using OpenNest.IO;
-using Xunit;
-
-namespace OpenNest.Tests.IO
-{
-    public class TitleBlockDetectorTests
-    {
-        private static Line MakeLine(double x1, double y1, double x2, double y2) =>
-            new Line(x1, y1, x2, y2);
-
-        [Fact]
-        public void DetectByLayerName_FlagsTitleLayer()
-        {
-            var line = MakeLine(0, 0, 10, 0);
-            line.Layer = new Layer("TITLE");
-            var entities = new List<Entity> { line };
-
-            var result = TitleBlockDetector.Detect(entities, null);
-
-            Assert.Contains(line.Id, result);
-        }
-
-        [Fact]
-        public void DetectByLayerName_CaseInsensitive()
-        {
-            var line = MakeLine(0, 0, 10, 0);
-            line.Layer = new Layer("border");
-            var entities = new List<Entity> { line };
-
-            var result = TitleBlockDetector.Detect(entities, null);
-
-            Assert.Contains(line.Id, result);
-        }
-
-        [Fact]
-        public void DetectByLayerName_IgnoresNonMatchingLayers()
-        {
-            var line = MakeLine(0, 0, 10, 0);
-            line.Layer = new Layer("0");
-            var entities = new List<Entity> { line };
-
-            var result = TitleBlockDetector.Detect(entities, null);
-
-            Assert.DoesNotContain(line.Id, result);
-        }
-
-        [Theory]
-        [InlineData("TITLE")]
-        [InlineData("TITLEBLOCK")]
-        [InlineData("TITLE_BLOCK")]
-        [InlineData("BORDER")]
-        [InlineData("FRAME")]
-        [InlineData("TB")]
-        [InlineData("INFO")]
-        [InlineData("SHEET")]
-        [InlineData("ANNOTATION")]
-        public void DetectByLayerName_AllKnownNames(string layerName)
-        {
-            var line = MakeLine(0, 0, 10, 0);
-            line.Layer = new Layer(layerName);
-            var entities = new List<Entity> { line };
-
-            var result = TitleBlockDetector.Detect(entities, null);
-
-            Assert.Contains(line.Id, result);
-        }
-
-        [Fact]
-        public void DetectBorder_FlagsLinesOnBoundingBoxEdges()
-        {
-            var entities = new List<Entity>
-            {
-                new Line(0, 0, 86, 0) { Layer = new Layer("0") },
-                new Line(86, 0, 86, 134) { Layer = new Layer("0") },
-                new Line(86, 134, 0, 134) { Layer = new Layer("0") },
-                new Line(0, 134, 0, 0) { Layer = new Layer("0") },
-                new Line(30, 40, 50, 90) { Layer = new Layer("0") },
-                new Line(50, 90, 70, 40) { Layer = new Layer("0") },
-                new Line(70, 40, 30, 40) { Layer = new Layer("0") },
-            };
-
-            var result = TitleBlockDetector.Detect(entities, null);
-
-            Assert.Contains(entities[0].Id, result);
-            Assert.Contains(entities[1].Id, result);
-            Assert.Contains(entities[2].Id, result);
-            Assert.Contains(entities[3].Id, result);
-            Assert.DoesNotContain(entities[4].Id, result);
-            Assert.DoesNotContain(entities[5].Id, result);
-            Assert.DoesNotContain(entities[6].Id, result);
-        }
-
-        [Fact]
-        public void DetectBorder_FlagsZoneMarkerTicks()
-        {
-            var entities = new List<Entity>
-            {
-                new Line(0, 0, 100, 0) { Layer = new Layer("0") },
-                new Line(100, 0, 100, 80) { Layer = new Layer("0") },
-                new Line(100, 80, 0, 80) { Layer = new Layer("0") },
-                new Line(0, 80, 0, 0) { Layer = new Layer("0") },
-                new Line(25, 80, 25, 77) { Layer = new Layer("0") },
-                new Line(50, 80, 50, 77) { Layer = new Layer("0") },
-                new Line(75, 80, 75, 77) { Layer = new Layer("0") },
-                new Line(40, 30, 60, 30) { Layer = new Layer("0") },
-            };
-
-            var result = TitleBlockDetector.Detect(entities, null);
-
-            Assert.Contains(entities[4].Id, result);
-            Assert.Contains(entities[5].Id, result);
-            Assert.Contains(entities[6].Id, result);
-            Assert.DoesNotContain(entities[7].Id, result);
-        }
-
-        [Fact]
-        public void DetectBorder_IgnoresWhenNoBorderPresent()
-        {
-            var entities = new List<Entity>
-            {
-                new Line(30, 40, 50, 90) { Layer = new Layer("0") },
-                new Line(50, 90, 70, 40) { Layer = new Layer("0") },
-                new Line(70, 40, 30, 40) { Layer = new Layer("0") },
-            };
-
-            var result = TitleBlockDetector.Detect(entities, null);
-
-            Assert.Empty(result);
-        }
-
-        [Fact]
-        public void DetectBorder_ToleratesSlightRotation()
-        {
-            var angleRad = OpenNest.Math.Angle.ToRadians(0.5);
-            var endY = 86 * System.Math.Sin(angleRad);
-            var entities = new List<Entity>
-            {
-                new Line(0, 0, 86, endY) { Layer = new Layer("0") },
-                new Line(86, endY, 86, 134) { Layer = new Layer("0") },
-                new Line(86, 134, 0, 134) { Layer = new Layer("0") },
-                new Line(0, 134, 0, 0) { Layer = new Layer("0") },
-                new Line(30, 40, 50, 90) { Layer = new Layer("0") },
-            };
-
-            var result = TitleBlockDetector.Detect(entities, null);
-
-            Assert.Contains(entities[0].Id, result);
-        }
-
-        [Fact]
-        public void DetectTitleBlock_FlagsEntitiesInTextDenseCorner()
-        {
-            var partLine1 = new Line(5, 70, 25, 120) { Layer = new Layer("0") };
-            var partLine2 = new Line(25, 120, 45, 70) { Layer = new Layer("0") };
-            var partLine3 = new Line(45, 70, 5, 70) { Layer = new Layer("0") };
-
-            var tbLines = new List<Entity>();
-            for (var x = 50; x <= 85; x += 5)
-                tbLines.Add(new Line(x, 0, x, 30) { Layer = new Layer("0") });
-            for (var y = 0; y <= 30; y += 5)
-                tbLines.Add(new Line(50, y, 85, y) { Layer = new Layer("0") });
-
-            var entities = new List<Entity> { partLine1, partLine2, partLine3 };
-            entities.AddRange(tbLines);
-
-            var doc = BuildDocWithTexts(
-                (60, 5, "TITLE: Test Part"),
-                (60, 10, "DWG NO: 12345"),
-                (60, 15, "SCALE: 1:1"),
-                (60, 20, "REV: A"),
-                (60, 25, "MATERIAL: STEEL"));
-
-            var result = TitleBlockDetector.Detect(entities, doc);
-
-            foreach (var tb in tbLines)
-                Assert.Contains(tb.Id, result);
-            Assert.DoesNotContain(partLine1.Id, result);
-            Assert.DoesNotContain(partLine2.Id, result);
-            Assert.DoesNotContain(partLine3.Id, result);
-        }
-
-        [Fact]
-        public void DetectTitleBlock_NoFalsePositivesWithoutText()
-        {
-            var entities = new List<Entity>
-            {
-                new Line(30, 40, 50, 90) { Layer = new Layer("0") },
-                new Line(50, 90, 70, 40) { Layer = new Layer("0") },
-                new Line(70, 40, 30, 40) { Layer = new Layer("0") },
-            };
-
-            var result = TitleBlockDetector.Detect(entities, null);
-
-            Assert.Empty(result);
-        }
-
-        [Fact]
-        public void DetectTitleBlock_BottomEdgeStrip()
-        {
-            var partLine = new Line(20, 40, 80, 40) { Layer = new Layer("0") };
-
-            var tbLines = new List<Entity>();
-            for (var x = 0; x <= 100; x += 10)
-                tbLines.Add(new Line(x, 0, x, 20) { Layer = new Layer("0") });
-            for (var y = 0; y <= 20; y += 5)
-                tbLines.Add(new Line(0, y, 100, y) { Layer = new Layer("0") });
-
-            var entities = new List<Entity> { partLine };
-            entities.AddRange(tbLines);
-
-            var doc = BuildDocWithTexts(
-                (10, 5, "TITLE"),
-                (30, 5, "DWG NO"),
-                (50, 5, "SCALE"),
-                (70, 5, "REV"),
-                (90, 5, "DATE"));
-
-            var result = TitleBlockDetector.Detect(entities, doc);
-
-            foreach (var tb in tbLines)
-                Assert.Contains(tb.Id, result);
-            Assert.DoesNotContain(partLine.Id, result);
-        }
-
-        private static ACadSharp.CadDocument BuildDocWithTexts(
-            params (double x, double y, string value)[] texts)
-        {
-            var doc = new ACadSharp.CadDocument();
-            foreach (var (x, y, value) in texts)
-            {
-                var mtext = new ACadSharp.Entities.MText
-                {
-                    InsertPoint = new XYZ(x, y, 0),
-                    Value = value,
-                    Height = 2.0
-                };
-                doc.Entities.Add(mtext);
-            }
-            return doc;
-        }
-    }
-}

OpenNest/Actions/ActionCutOff.cs

@@ -16,11 +16,15 @@ namespace OpenNest.Actions
         private CutOffSettings settings;
         private CutOffAxis lockedAxis = CutOffAxis.Vertical;
         private Dictionary<Part, Entity> perimeterCache;
+        private readonly Timer debounceTimer;
+        private bool regeneratePending;
 
         public ActionCutOff(PlateView plateView)
             : base(plateView)
         {
             settings = plateView.CutOffSettings;
+            debounceTimer = new Timer { Interval = 16 };
+            debounceTimer.Tick += OnDebounce;
             ConnectEvents();
         }
 
@@ -36,6 +40,8 @@ namespace OpenNest.Actions
 
         public override void DisconnectEvents()
         {
+            debounceTimer.Stop();
+            debounceTimer.Dispose();
             plateView.MouseMove -= OnMouseMove;
             plateView.MouseDown -= OnMouseDown;
             plateView.KeyDown -= OnKeyDown;
@@ -52,6 +58,18 @@ namespace OpenNest.Actions
 
         private void OnMouseMove(object sender, MouseEventArgs e)
         {
+            regeneratePending = true;
+            debounceTimer.Start();
+        }
+
+        private void OnDebounce(object sender, System.EventArgs e)
+        {
+            debounceTimer.Stop();
+
+            if (!regeneratePending)
+                return;
+
+            regeneratePending = false;
             var pt = plateView.CurrentPoint;
             previewCutOff = new CutOff(pt, lockedAxis);
             previewCutOff.Regenerate(plateView.Plate, settings, perimeterCache);

OpenNest/Controls/EntityView.cs

@@ -30,16 +30,13 @@ namespace OpenNest.Controls
         public List<Entity> OriginalEntities { get; set; }
         public bool ShowEntityLabels { get; set; }
         public List<CadText> Texts { get; set; } = new List<CadText>();
-        public HashSet<Guid> TitleBlockEntityIds { get; set; }
 
         private readonly Pen gridPen = new Pen(Color.FromArgb(70, 70, 70));
         private readonly Dictionary<int, Pen> penCache = new Dictionary<int, Pen>();
-        private readonly Dictionary<int, Pen> ghostPenCache = new Dictionary<int, Pen>();
         private readonly Font labelFont = new Font("Segoe UI", 7f);
         private readonly SolidBrush labelBrush = new SolidBrush(Color.FromArgb(220, 255, 255, 200));
         private readonly SolidBrush labelBackBrush = new SolidBrush(Color.FromArgb(33, 40, 48));
         private readonly SolidBrush textBrush = new SolidBrush(Color.FromArgb(180, 200, 200, 200));
-        private readonly SolidBrush ghostTextBrush = new SolidBrush(Color.FromArgb(50, 200, 200, 200));
 
         public event EventHandler<Line> LinePicked;
         public event EventHandler PickCancelled;
@@ -105,13 +102,6 @@ namespace OpenNest.Controls
             foreach (var entity in Entities)
             {
                 if (IsEtchLayer(entity.Layer)) continue;
-
-                if (TitleBlockEntityIds != null && TitleBlockEntityIds.Contains(entity.Id))
-                {
-                    DrawGhostEntity(e.Graphics, entity);
-                    continue;
-                }
-
                 var isHighlighted = simplifierHighlightSet != null && simplifierHighlightSet.Contains(entity);
                 var pen = isHighlighted
                     ? GetEntityPen(Color.FromArgb(60, entity.Color))
@@ -253,26 +243,11 @@ namespace OpenNest.Controls
             return pen;
         }
 
-        private Pen GetGhostPen(Color color)
-        {
-            var ghostColor = Color.FromArgb(60, color.R, color.G, color.B);
-            var argb = ghostColor.ToArgb();
-            if (!ghostPenCache.TryGetValue(argb, out var pen))
-            {
-                pen = new Pen(ghostColor);
-                ghostPenCache[argb] = pen;
-            }
-            return pen;
-        }
-
         public void ClearPenCache()
         {
             foreach (var pen in penCache.Values)
                 pen.Dispose();
             penCache.Clear();
-            foreach (var pen in ghostPenCache.Values)
-                pen.Dispose();
-            ghostPenCache.Clear();
         }
 
         private static bool IsEtchLayer(Layer layer) =>
@@ -438,28 +413,10 @@ namespace OpenNest.Controls
                 labelBrush.Dispose();
                 labelBackBrush.Dispose();
                 textBrush.Dispose();
-                ghostTextBrush.Dispose();
             }
             base.Dispose(disposing);
         }
 
-        private void DrawGhostEntity(Graphics g, Entity e)
-        {
-            var pen = GetGhostPen(e.Color);
-            switch (e.Type)
-            {
-                case EntityType.Arc:
-                    DrawArc(g, (Arc)e, pen);
-                    break;
-                case EntityType.Circle:
-                    DrawCircle(g, (Circle)e, pen);
-                    break;
-                case EntityType.Line:
-                    DrawLine(g, (Line)e, pen);
-                    break;
-            }
-        }
-
         private void DrawEntity(Graphics g, Entity e, Pen pen)
         {
             if (!e.Layer.IsVisible || !e.IsVisible)
@@ -544,10 +501,8 @@ namespace OpenNest.Controls
                 sf.Alignment = text.HAlign;
                 sf.LineAlignment = text.VAlign;
 
-                var brush = TitleBlockEntityIds != null && TitleBlockEntityIds.Count > 0
-                    ? ghostTextBrush : textBrush;
                 using var font = new Font("Segoe UI", fontSize, GraphicsUnit.Pixel);
-                g.DrawString(text.Value, font, brush, 0, 0, sf);
+                g.DrawString(text.Value, font, textBrush, 0, 0, sf);
                 g.Restore(state);
             }
         }

OpenNest/Controls/FileListControl.cs

@@ -20,7 +20,6 @@ namespace OpenNest.Controls
         public List<Entity> OriginalEntities { get; set; }
         public List<Bend> Bends { get; set; } = new();
         public HashSet<Guid> SuppressedEntityIds { get; set; }
-        public HashSet<Guid> TitleBlockEntityIds { get; set; }
         public Box Bounds { get; set; }
         public int EntityCount { get; set; }
         public List<CadText> Texts { get; set; } = new();

OpenNest/Forms/CadConverterForm.cs

@@ -94,16 +94,8 @@ namespace OpenNest.Forms
                     Bounds = result.Bounds,
                     EntityCount = result.Entities.Count,
                     Texts = ExtractTexts(result.Document),
-                    TitleBlockEntityIds = result.TitleBlockEntityIds,
                 };
 
-                if (result.TitleBlockEntityIds != null && result.TitleBlockEntityIds.Count > 0)
-                {
-                    item.SuppressedEntityIds ??= new HashSet<Guid>();
-                    foreach (var id in result.TitleBlockEntityIds)
-                        item.SuppressedEntityIds.Add(id);
-                }
-
                 if (InvokeRequired)
                     BeginInvoke((Action)(() => fileList.AddItem(item)));
                 else
@@ -162,7 +154,6 @@ namespace OpenNest.Forms
             entityView1.Entities.AddRange(item.Entities);
             entityView1.Bends = item.Bends ?? new List<Bend>();
             entityView1.Texts = item.Texts ?? new List<CadText>();
-            entityView1.TitleBlockEntityIds = item.TitleBlockEntityIds;
 
             item.Entities.ForEach(e => e.IsVisible = true);
             if (item.Entities.Any(e => e.Layer != null))