From 00ede7c5d075d0b706cc1251bd20d8767fa9d06c Mon Sep 17 00:00:00 2001
From: AJ Isaacs <ajisaacs27@gmail.com>
Date: Tue, 29 Sep 2026 19:27:23 -0400
Subject: [PATCH] fix(math): normalize degree interval checks in degrees

---
 OpenNest.Core/Math/Angle.cs       |  8 +--
 OpenNest.Tests/Math/AngleTests.cs | 82 +++++++++++++++++++++++++++++++
 2 files changed, 86 insertions(+), 4 deletions(-)
 create mode 100644 OpenNest.Tests/Math/AngleTests.cs

diff --git a/OpenNest.Core/Math/Angle.cs b/OpenNest.Core/Math/Angle.cs
index 82708f2..6023e42 100644
--- a/OpenNest.Core/Math/Angle.cs
+++ b/OpenNest.Core/Math/Angle.cs
@@ -1,4 +1,4 @@
-namespace OpenNest.Math
+namespace OpenNest.Math
 {
     public static class Angle
     {
@@ -106,14 +106,14 @@
             if (reversed)
                 Generic.Swap(ref a1, ref a2);
 
-            var diff = Angle.NormalizeRad(a2 - a1);
+            var diff = Angle.NormalizeDeg(a2 - a1);
 
             // full circle
             if (a2.IsEqualTo(a1))
                 return true;
 
-            a1 = Angle.NormalizeRad(angle - a1);
-            a2 = Angle.NormalizeRad(a2 - angle);
+            a1 = Angle.NormalizeDeg(angle - a1);
+            a2 = Angle.NormalizeDeg(a2 - angle);
 
             return diff >= a1 - Tolerance.Epsilon || diff >= a2 - Tolerance.Epsilon;
         }
diff --git a/OpenNest.Tests/Math/AngleTests.cs b/OpenNest.Tests/Math/AngleTests.cs
new file mode 100644
index 0000000..d7dfee6
--- /dev/null
+++ b/OpenNest.Tests/Math/AngleTests.cs
@@ -0,0 +1,82 @@
+using Xunit;
+
+namespace OpenNest.Tests.Math;
+
+public class AngleTests
+{
+    [Theory]
+    [InlineData(10, 0, 90, true)]
+    [InlineData(180, 0, 90, false)]
+    [InlineData(0, 0, 90, true)]
+    [InlineData(90, 0, 90, true)]
+    [InlineData(350, 340, 10, true)]
+    [InlineData(20, 340, 10, false)]
+    [InlineData(-10, 340, 10, true)]
+    [InlineData(370, 0, 90, true)]
+    [InlineData(123, 45, 45, true)]
+    public void IsBetweenDeg_ReturnsExpected(double angle, double a1, double a2, bool expected)
+    {
+        Assert.Equal(expected, OpenNest.Math.Angle.IsBetweenDeg(angle, a1, a2));
+    }
+
+    [Theory]
+    [InlineData(45, 90, 0, true)]
+    [InlineData(45, 0, 90, false)]
+    public void IsBetweenDeg_Reversed_SwapsEndpoints(double angle, double a1, double a2, bool expected)
+    {
+        Assert.Equal(expected, OpenNest.Math.Angle.IsBetweenDeg(angle, a1, a2, reversed: true));
+    }
+
+    [Theory]
+    [InlineData(10, 0, 90, false)]
+    [InlineData(45, 0, 90, false)]
+    [InlineData(180, 0, 90, false)]
+    [InlineData(0, 0, 90, false)]
+    [InlineData(90, 0, 90, false)]
+    [InlineData(350, 340, 10, false)]
+    [InlineData(20, 340, 10, false)]
+    [InlineData(-10, 340, 10, false)]
+    [InlineData(370, 0, 90, false)]
+    [InlineData(123, 45, 45, false)]
+    [InlineData(45, 90, 0, true)]
+    [InlineData(45, 0, 90, true)]
+    public void IsBetweenDeg_OrdinaryCases_MatchesRadians(
+        double angle, double a1, double a2, bool reversed)
+    {
+        var radianResult = OpenNest.Math.Angle.IsBetweenRad(
+            angle * System.Math.PI / 180,
+            a1 * System.Math.PI / 180,
+            a2 * System.Math.PI / 180,
+            reversed);
+
+        Assert.Equal(radianResult, OpenNest.Math.Angle.IsBetweenDeg(angle, a1, a2, reversed));
+    }
+
+    [Theory]
+    [InlineData(-0.000005, 0, 90, true)]
+    [InlineData(-0.00002, 0, 90, false)]
+    [InlineData(90.000005, 0, 90, true)]
+    [InlineData(90.00002, 0, 90, false)]
+    [InlineData(123, 45, 45.000005, true)]
+    [InlineData(123, 45, 45.00002, false)]
+    [InlineData(123, 45, 405, false)]
+    public void IsBetweenDeg_UsesDegreeToleranceBeforeNormalizingEndpoints(
+        double angle, double a1, double a2, bool expected)
+    {
+        Assert.Equal(expected, OpenNest.Math.Angle.IsBetweenDeg(angle, a1, a2));
+    }
+
+    [Theory]
+    [InlineData(-0.000005, 0, 1, true)]
+    [InlineData(-0.00002, 0, 1, false)]
+    [InlineData(1.000005, 0, 1, true)]
+    [InlineData(1.00002, 0, 1, false)]
+    [InlineData(2, 0.5, 0.500005, true)]
+    [InlineData(2, 0.5, 0.50002, false)]
+    [InlineData(2, 0.5, 0.5 + 2 * System.Math.PI, false)]
+    public void IsBetweenRad_UsesRadianToleranceBeforeNormalizingEndpoints(
+        double angle, double a1, double a2, bool expected)
+    {
+        Assert.Equal(expected, OpenNest.Math.Angle.IsBetweenRad(angle, a1, a2));
+    }
+}