Add some unit tests for Av1Math

src/ImageSharp/Formats/Heif/Av1/Av1Math.cs

@@ -26,17 +26,6 @@ internal static class Av1Math
         return log;
     }
 
-    public static uint Log2(uint n)
-    {
-        uint result = 0U;
-        while ((n >>= 1) > 0)
-        {
-            result++;
-        }
-
-        return result;
-    }
-
     public static int Log2(int n)
     {
         int result = 0;

src/ImageSharp/Formats/Heif/Av1/Transform/Inverse/Av1Adst32Inverse1dTransformer.cs

@@ -1,8 +1,6 @@
 // Copyright (c) Six Labors.
 // Licensed under the Six Labors Split License.
 
-using System.Drawing;
-using System;
 using System.Runtime.CompilerServices;
 
 namespace SixLabors.ImageSharp.Formats.Heif.Av1.Transform.Inverse;

tests/ImageSharp.Tests/Formats/Heif/Av1/Av1MathTests.cs

@@ -8,6 +8,81 @@ namespace SixLabors.ImageSharp.Tests.Formats.Heif.Av1;
 [Trait("Format", "Avif")]
 public class Av1MathTests
 {
+    [Theory]
+    [InlineData(1, 0)]
+    [InlineData(2, 1)]
+    [InlineData(3, 1)]
+    [InlineData(4, 2)]
+    [InlineData(5, 2)]
+    [InlineData(7, 2)]
+    [InlineData(8, 3)]
+    [InlineData(9, 3)]
+    public void TestMostSignificantBit(uint value, int expected)
+    {
+        int actual = Av1Math.MostSignificantBit(value);
+        Assert.Equal(expected, actual);
+    }
+
+    [Theory]
+    [InlineData(1, 0)]
+    [InlineData(2, 1)]
+    [InlineData(3, 1)]
+    [InlineData(4, 2)]
+    [InlineData(5, 2)]
+    [InlineData(7, 2)]
+    [InlineData(8, 3)]
+    [InlineData(9, 3)]
+    public void TestLog2(int value, int expected)
+    {
+        int actual = Av1Math.Log2(value);
+        Assert.Equal(expected, actual);
+    }
+
+    [Theory]
+    [InlineData(1, 0)]
+    [InlineData(2, 1)]
+    [InlineData(3, 1)]
+    [InlineData(4, 2)]
+    [InlineData(5, 2)]
+    [InlineData(7, 2)]
+    [InlineData(8, 3)]
+    [InlineData(9, 3)]
+    public void TestFloorLog2(uint value, uint expected)
+    {
+        uint actual = Av1Math.FloorLog2(value);
+        Assert.Equal(expected, actual);
+    }
+
+    [Theory]
+    [InlineData(1, 0)]
+    [InlineData(2, 1)]
+    [InlineData(3, 1)]
+    [InlineData(4, 2)]
+    [InlineData(5, 2)]
+    [InlineData(7, 2)]
+    [InlineData(8, 3)]
+    [InlineData(9, 3)]
+    public void TestLog2_32(uint value, uint expected)
+    {
+        uint actual = Av1Math.Log2_32(value);
+        Assert.Equal(expected, actual);
+    }
+
+    [Theory]
+    [InlineData(1, 0)]
+    [InlineData(2, 1)]
+    [InlineData(3, 2)]
+    [InlineData(4, 2)]
+    [InlineData(5, 3)]
+    [InlineData(7, 3)]
+    [InlineData(8, 3)]
+    [InlineData(9, 4)]
+    public void TestLog2Ceiling(uint value, uint expected)
+    {
+        uint actual = Av1Math.CeilLog2(value);
+        Assert.Equal(expected, actual);
+    }
+
     [Theory]
     [InlineData(4, 2, 1)]
     [InlineData(4, 3, 0)]