Add some XYZ tests

src/ImageSharp/ColorProfiles/CieLuv.cs

@@ -94,7 +94,7 @@ public readonly struct CieLuv : IColorProfile<CieLuv, CieXyz>
             ? ((116 * Math.Pow(yr, e)) - 16d)
             : (CieConstants.Kappa * yr);
 
-        if (double.IsNaN(l))
+        if (double.IsNaN(l) || l == -0d)
         {
             l = 0;
         }
@@ -107,7 +107,7 @@ public readonly struct CieLuv : IColorProfile<CieLuv, CieXyz>
             u = 0;
         }
 
-        if (double.IsNaN(v) || u == -0d)
+        if (double.IsNaN(v) || v == -0d)
         {
             v = 0;
         }
@@ -151,17 +151,17 @@ public readonly struct CieLuv : IColorProfile<CieLuv, CieXyz>
         double x = (d - b) / (a - c);
         double z = (x * a) + b;
 
-        if (double.IsNaN(x))
+        if (double.IsNaN(x) || x == -0d)
         {
             x = 0;
         }
 
-        if (double.IsNaN(y))
+        if (double.IsNaN(y) || y == -0d)
         {
             y = 0;
         }
 
-        if (double.IsNaN(z))
+        if (double.IsNaN(z) || z == -0d)
         {
             z = 0;
         }

tests/ImageSharp.Tests/ColorProfiles/CieXyzAndCieLchuvConversionTests.cs

@@ -0,0 +1,69 @@
+// Copyright (c) Six Labors.
+// Licensed under the Six Labors Split License.
+
+using SixLabors.ImageSharp.ColorProfiles;
+
+namespace SixLabors.ImageSharp.Tests.ColorProfiles;
+
+/// <summary>
+/// Tests <see cref="CieXyz"/>-<see cref="CieLchuv"/> conversions.
+/// </summary>
+public class CieXyzAndCieLchuvConversionTests
+{
+    private static readonly ApproximateColorProfileComparer Comparer = new(.0002f);
+
+    [Theory]
+    [InlineData(0.360555, 0.936901, 0.1001514, 97.50697, 177.345169, 142.601547)]
+    public void Convert_CieXyz_to_CieLchuv(float x, float y, float yl, float l, float c, float h)
+    {
+        // Arrange
+        CieXyz input = new(x, y, yl);
+        CieLchuv expected = new(l, c, h);
+        ColorProfileConverter converter = new();
+
+        Span<CieXyz> inputSpan = new CieXyz[5];
+        inputSpan.Fill(input);
+
+        Span<CieLchuv> actualSpan = new CieLchuv[5];
+
+        // Act
+        CieLchuv actual = converter.Convert<CieXyz, CieLchuv>(input);
+        converter.Convert<CieXyz, CieLchuv>(inputSpan, actualSpan);
+
+        // Assert
+        Assert.Equal(expected, actual, Comparer);
+
+        for (int i = 0; i < actualSpan.Length; i++)
+        {
+            Assert.Equal(expected, actualSpan[i], Comparer);
+        }
+    }
+
+    [Theory]
+    [InlineData(0, 0, 0, 0, 0, 0)]
+    [InlineData(97.50697, 177.345169, 142.601547, 0.360555, 0.936901, 0.1001514)]
+    public void Convert_CieLchuv_to_CieXyz(float l, float c, float h, float x, float y, float yl)
+    {
+        // Arrange
+        CieLchuv input = new(l, c, h);
+        CieXyz expected = new(x, y, yl);
+        ColorProfileConverter converter = new();
+
+        Span<CieLchuv> inputSpan = new CieLchuv[5];
+        inputSpan.Fill(input);
+
+        Span<CieXyz> actualSpan = new CieXyz[5];
+
+        // Act
+        CieXyz actual = converter.Convert<CieLchuv, CieXyz>(input);
+        converter.Convert<CieLchuv, CieXyz>(inputSpan, actualSpan);
+
+        // Assert
+        Assert.Equal(expected, actual, Comparer);
+
+        for (int i = 0; i < actualSpan.Length; i++)
+        {
+            Assert.Equal(expected, actualSpan[i], Comparer);
+        }
+    }
+}

tests/ImageSharp.Tests/ColorProfiles/CieXyzAndCieLuvConversionTest.cs

@@ -0,0 +1,86 @@
+// Copyright (c) Six Labors.
+// Licensed under the Six Labors Split License.
+
+using SixLabors.ImageSharp.ColorProfiles;
+
+namespace SixLabors.ImageSharp.Tests.ColorProfiles;
+
+/// <summary>
+/// Tests <see cref="CieXyz"/>-<see cref="CieLuv"/> conversions.
+/// </summary>
+/// <remarks>
+/// Test data generated using:
+/// <see href="http://www.brucelindbloom.com/index.html?ColorCalculator.html"/>
+/// </remarks>
+public class CieXyzAndCieLuvConversionTest
+{
+    private static readonly ApproximateColorProfileComparer Comparer = new(.0002f);
+
+    [Theory]
+    [InlineData(0, 0, 0, 0, 0, 0)]
+    [InlineData(0, 100, 50, 0, 0, 0)]
+    [InlineData(0.1, 100, 50, 0.000493, 0.000111, -0.000709)]
+    [InlineData(70.0000, 86.3525, 2.8240, 0.569310, 0.407494, 0.365843)]
+    [InlineData(10.0000, -1.2345, -10.0000, 0.012191, 0.011260, 0.025939)]
+    [InlineData(100, 0, 0, 0.950470, 1.000000, 1.088830)]
+    [InlineData(1, 1, 1, 0.001255, 0.001107, 0.000137)]
+    public void Convert_Luv_to_Xyz(float l, float u, float v, float x, float y, float z)
+    {
+        // Arrange
+        CieLuv input = new(l, u, v);
+        CieXyz expected = new(x, y, z);
+
+        ColorConversionOptions options = new() { WhitePoint = Illuminants.D65, TargetWhitePoint = Illuminants.D65 };
+        ColorProfileConverter converter = new(options);
+
+        Span<CieLuv> inputSpan = new CieLuv[5];
+        inputSpan.Fill(input);
+
+        Span<CieXyz> actualSpan = new CieXyz[5];
+
+        // Act
+        CieXyz actual = converter.Convert<CieLuv, CieXyz>(input);
+        converter.Convert<CieLuv, CieXyz>(inputSpan, actualSpan);
+
+        // Assert
+        Assert.Equal(expected, actual, Comparer);
+
+        for (int i = 0; i < actualSpan.Length; i++)
+        {
+            Assert.Equal(expected, actualSpan[i], Comparer);
+        }
+    }
+
+    [Theory]
+    [InlineData(0, 0, 0, 0, 0, 0)]
+    [InlineData(0.000493, 0.000111, 0, 0.1003, 0.9332, -0.0070)]
+    [InlineData(0.569310, 0.407494, 0.365843, 70.0000, 86.3524, 2.8240)]
+    [InlineData(0.012191, 0.011260, 0.025939, 9.9998, -1.2343, -9.9999)]
+    [InlineData(0.950470, 1.000000, 1.088830, 100, 0, 0)]
+    [InlineData(0.001255, 0.001107, 0.000137, 0.9999, 0.9998, 1.0004)]
+    public void Convert_Xyz_to_Luv(float x, float y, float z, float l, float u, float v)
+    {
+        // Arrange
+        CieXyz input = new(x, y, z);
+        CieLuv expected = new(l, u, v);
+
+        ColorConversionOptions options = new() { WhitePoint = Illuminants.D65, TargetWhitePoint = Illuminants.D65 };
+        ColorProfileConverter converter = new(options);
+
+        Span<CieXyz> inputSpan = new CieXyz[5];
+        inputSpan.Fill(input);
+
+        Span<CieLuv> actualSpan = new CieLuv[5];
+
+        // Act
+        CieLuv actual = converter.Convert<CieXyz, CieLuv>(input);
+
+        // Assert
+        Assert.Equal(expected, actual, Comparer);
+
+        for (int i = 0; i < actualSpan.Length; i++)
+        {
+            Assert.Equal(expected, actualSpan[i], Comparer);
+        }
+    }
+}