feat: remove duplicate arcs matching circles on same layer during DXF import

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

OpenNest.IO/CadImporter.cs

@@ -5,6 +5,7 @@ using OpenNest.Bending;
 using OpenNest.Converters;
 using OpenNest.Geometry;
 using OpenNest.IO.Bending;
+using OpenNest.Math;
 
 namespace OpenNest.IO
 {
@@ -25,6 +26,8 @@ namespace OpenNest.IO
 
             var dxf = Dxf.Import(path);
 
+            RemoveDuplicateArcs(dxf.Entities);
+
             var bends = new List<Bend>();
             if (options.DetectBends && dxf.Document != null)
             {
@@ -136,5 +139,33 @@ namespace OpenNest.IO
 
             return drawing;
         }
+
+        internal static void RemoveDuplicateArcs(List<Entity> entities)
+        {
+            var circles = entities.OfType<Circle>().ToList();
+            var arcs = entities.OfType<Arc>().ToList();
+            var arcsToRemove = new List<Arc>();
+
+            foreach (var arc in arcs)
+            {
+                foreach (var circle in circles)
+                {
+                    if (arc.Layer?.Name != circle.Layer?.Name)
+                        continue;
+
+                    if (!arc.Center.DistanceTo(circle.Center).IsEqualTo(0))
+                        continue;
+
+                    if (!arc.Radius.IsEqualTo(circle.Radius))
+                        continue;
+
+                    arcsToRemove.Add(arc);
+                    break;
+                }
+            }
+
+            foreach (var arc in arcsToRemove)
+                entities.Remove(arc);
+        }
     }
 }

OpenNest.Tests/IO/RemoveDuplicateArcsTests.cs

@@ -0,0 +1,96 @@
+using System.Collections.Generic;
+using System.Linq;
+using OpenNest.Geometry;
+using OpenNest.IO;
+using OpenNest.Math;
+using Xunit;
+
+namespace OpenNest.Tests.IO;
+
+public class RemoveDuplicateArcsTests
+{
+    [Fact]
+    public void RemoveDuplicateArcs_RemovesArcMatchingCircle_SameLayer()
+    {
+        var layer = new Layer("0");
+        var circle = new Circle(10, 10, 5) { Layer = layer };
+        var arc = new Arc(10, 10, 5, 0, Angle.ToRadians(90)) { Layer = layer };
+        var line = new Line(0, 0, 10, 0) { Layer = layer };
+        var entities = new List<Entity> { circle, arc, line };
+
+        CadImporter.RemoveDuplicateArcs(entities);
+
+        Assert.Equal(2, entities.Count);
+        Assert.Contains(circle, entities);
+        Assert.Contains(line, entities);
+        Assert.DoesNotContain(arc, entities);
+    }
+
+    [Fact]
+    public void RemoveDuplicateArcs_KeepsArcOnDifferentLayer()
+    {
+        var layer1 = new Layer("cut");
+        var layer2 = new Layer("etch");
+        var circle = new Circle(10, 10, 5) { Layer = layer1 };
+        var arc = new Arc(10, 10, 5, 0, Angle.ToRadians(90)) { Layer = layer2 };
+        var entities = new List<Entity> { circle, arc };
+
+        CadImporter.RemoveDuplicateArcs(entities);
+
+        Assert.Equal(2, entities.Count);
+        Assert.Contains(arc, entities);
+    }
+
+    [Fact]
+    public void RemoveDuplicateArcs_KeepsArcWithDifferentRadius()
+    {
+        var layer = new Layer("0");
+        var circle = new Circle(10, 10, 5) { Layer = layer };
+        var arc = new Arc(10, 10, 3, 0, Angle.ToRadians(90)) { Layer = layer };
+        var entities = new List<Entity> { circle, arc };
+
+        CadImporter.RemoveDuplicateArcs(entities);
+
+        Assert.Equal(2, entities.Count);
+    }
+
+    [Fact]
+    public void RemoveDuplicateArcs_KeepsArcWithDifferentCenter()
+    {
+        var layer = new Layer("0");
+        var circle = new Circle(10, 10, 5) { Layer = layer };
+        var arc = new Arc(20, 20, 5, 0, Angle.ToRadians(90)) { Layer = layer };
+        var entities = new List<Entity> { circle, arc };
+
+        CadImporter.RemoveDuplicateArcs(entities);
+
+        Assert.Equal(2, entities.Count);
+    }
+
+    [Fact]
+    public void RemoveDuplicateArcs_NoCircles_NoChange()
+    {
+        var arc = new Arc(10, 10, 5, 0, Angle.ToRadians(90));
+        var line = new Line(0, 0, 10, 0);
+        var entities = new List<Entity> { arc, line };
+
+        CadImporter.RemoveDuplicateArcs(entities);
+
+        Assert.Equal(2, entities.Count);
+    }
+
+    [Fact]
+    public void RemoveDuplicateArcs_MultipleArcsMatchOneCircle_RemovesAll()
+    {
+        var layer = new Layer("0");
+        var circle = new Circle(10, 10, 5) { Layer = layer };
+        var arc1 = new Arc(10, 10, 5, 0, Angle.ToRadians(90)) { Layer = layer };
+        var arc2 = new Arc(10, 10, 5, Angle.ToRadians(90), Angle.ToRadians(180)) { Layer = layer };
+        var entities = new List<Entity> { circle, arc1, arc2 };
+
+        CadImporter.RemoveDuplicateArcs(entities);
+
+        Assert.Single(entities);
+        Assert.Contains(circle, entities);
+    }
+}