feat: add VerticalRemnantComparer and HorizontalRemnantComparer

Implements two IFillComparer strategies that preserve axis-aligned remnants: VerticalRemnantComparer minimizes X-extent, HorizontalRemnantComparer minimizes Y-extent, both using a count > extent > density tiebreak chain. Includes 12 unit tests covering all tiebreak levels and null-guard cases. Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
2026-03-21 12:38:23 -04:00
parent f894ffd27c
commit 1a41eeb81d
3 changed files with 206 additions and 0 deletions
@@ -63,3 +63,111 @@ public class DefaultFillComparerTests
        Assert.True(comparer.IsBetter(candidate, current, workArea));
    }
 }
+
+public class VerticalRemnantComparerTests
+{
+    private readonly IFillComparer comparer = new VerticalRemnantComparer();
+    private readonly Box workArea = new(0, 0, 100, 100);
+
+    [Fact]
+    public void HigherCount_WinsRegardlessOfExtent()
+    {
+        var candidate = new List<Part>
+        {
+            TestHelpers.MakePartAt(0, 0, 10),
+            TestHelpers.MakePartAt(40, 0, 10),
+            TestHelpers.MakePartAt(80, 0, 10)
+        };
+        var current = new List<Part>
+        {
+            TestHelpers.MakePartAt(0, 0, 10),
+            TestHelpers.MakePartAt(12, 0, 10)
+        };
+        Assert.True(comparer.IsBetter(candidate, current, workArea));
+    }
+
+    [Fact]
+    public void SameCount_SmallerXExtent_Wins()
+    {
+        var candidate = new List<Part>
+        {
+            TestHelpers.MakePartAt(0, 0, 10),
+            TestHelpers.MakePartAt(12, 0, 10)
+        };
+        var current = new List<Part>
+        {
+            TestHelpers.MakePartAt(0, 0, 10),
+            TestHelpers.MakePartAt(50, 0, 10)
+        };
+        Assert.True(comparer.IsBetter(candidate, current, workArea));
+    }
+
+    [Fact]
+    public void SameCount_SameExtent_HigherDensityWins()
+    {
+        var candidate = new List<Part>
+        {
+            TestHelpers.MakePartAt(0, 0, 10),
+            TestHelpers.MakePartAt(40, 0, 10)
+        };
+        var current = new List<Part>
+        {
+            TestHelpers.MakePartAt(0, 0, 10),
+            TestHelpers.MakePartAt(40, 40, 10)
+        };
+        Assert.True(comparer.IsBetter(candidate, current, workArea));
+    }
+
+    [Fact]
+    public void NullCandidate_ReturnsFalse()
+    {
+        var current = new List<Part> { TestHelpers.MakePartAt(0, 0, 10) };
+        Assert.False(comparer.IsBetter(null, current, workArea));
+    }
+
+    [Fact]
+    public void NullCurrent_ReturnsTrue()
+    {
+        var candidate = new List<Part> { TestHelpers.MakePartAt(0, 0, 10) };
+        Assert.True(comparer.IsBetter(candidate, null, workArea));
+    }
+}
+
+public class HorizontalRemnantComparerTests
+{
+    private readonly IFillComparer comparer = new HorizontalRemnantComparer();
+    private readonly Box workArea = new(0, 0, 100, 100);
+
+    [Fact]
+    public void SameCount_SmallerYExtent_Wins()
+    {
+        var candidate = new List<Part>
+        {
+            TestHelpers.MakePartAt(0, 0, 10),
+            TestHelpers.MakePartAt(0, 12, 10)
+        };
+        var current = new List<Part>
+        {
+            TestHelpers.MakePartAt(0, 0, 10),
+            TestHelpers.MakePartAt(0, 50, 10)
+        };
+        Assert.True(comparer.IsBetter(candidate, current, workArea));
+    }
+
+    [Fact]
+    public void HigherCount_WinsRegardlessOfExtent()
+    {
+        var candidate = new List<Part>
+        {
+            TestHelpers.MakePartAt(0, 0, 10),
+            TestHelpers.MakePartAt(0, 40, 10),
+            TestHelpers.MakePartAt(0, 80, 10)
+        };
+        var current = new List<Part>
+        {
+            TestHelpers.MakePartAt(0, 0, 10),
+            TestHelpers.MakePartAt(0, 12, 10)
+        };
+        Assert.True(comparer.IsBetter(candidate, current, workArea));
+    }
+}