From 5d0de4a1b160e671aee5dd633dded6f9fb85868e Mon Sep 17 00:00:00 2001
From: AJ Isaacs <ajisaacs27@gmail.com>
Date: Tue, 17 Mar 2026 07:59:26 -0400
Subject: [PATCH] feat(core): add CircleShape

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
---
 OpenNest.Core/Shapes/CircleShape.cs       | 20 +++++++++++++++++
 OpenNest.Tests/Shapes/CircleShapeTests.cs | 26 +++++++++++++++++++++++
 2 files changed, 46 insertions(+)
 create mode 100644 OpenNest.Core/Shapes/CircleShape.cs
 create mode 100644 OpenNest.Tests/Shapes/CircleShapeTests.cs

diff --git a/OpenNest.Core/Shapes/CircleShape.cs b/OpenNest.Core/Shapes/CircleShape.cs
new file mode 100644
index 0000000..6288cef
--- /dev/null
+++ b/OpenNest.Core/Shapes/CircleShape.cs
@@ -0,0 +1,20 @@
+using System.Collections.Generic;
+using OpenNest.Geometry;
+
+namespace OpenNest.Shapes
+{
+    public class CircleShape : ShapeDefinition
+    {
+        public double Diameter { get; set; }
+
+        public override Drawing GetDrawing()
+        {
+            var entities = new List<Entity>
+            {
+                new Circle(0, 0, Diameter / 2.0)
+            };
+
+            return CreateDrawing(entities);
+        }
+    }
+}
diff --git a/OpenNest.Tests/Shapes/CircleShapeTests.cs b/OpenNest.Tests/Shapes/CircleShapeTests.cs
new file mode 100644
index 0000000..0b4de30
--- /dev/null
+++ b/OpenNest.Tests/Shapes/CircleShapeTests.cs
@@ -0,0 +1,26 @@
+using OpenNest.Shapes;
+
+namespace OpenNest.Tests.Shapes;
+
+public class CircleShapeTests
+{
+    [Fact]
+    public void GetDrawing_ReturnsDrawingWithCorrectBoundingBox()
+    {
+        var shape = new CircleShape { Diameter = 10 };
+        var drawing = shape.GetDrawing();
+
+        var bbox = drawing.Program.BoundingBox();
+        Assert.Equal(10, bbox.Width, 0.01);
+        Assert.Equal(10, bbox.Length, 0.01);
+    }
+
+    [Fact]
+    public void GetDrawing_DefaultName_IsCircle()
+    {
+        var shape = new CircleShape { Diameter = 10 };
+        var drawing = shape.GetDrawing();
+
+        Assert.Equal("Circle", drawing.Name);
+    }
+}