ImageSharp/tests/ImageSharp.Tests/ColorProfiles/RgbAndCieXyzConversionTest.cs

// 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="Rgb"/> conversions.
/// </summary>
/// <remarks>
/// Test data generated using:
/// <see href="http://www.brucelindbloom.com/index.html?ColorCalculator.html"/>
/// </remarks>
public class RgbAndCieXyzConversionTest
{
    private static readonly ApproximateColorProfileComparer Comparer = new(.0001F);

    [Theory]
    [InlineData(0.96422, 1.00000, 0.82521, 1, 1, 1)]
    [InlineData(0.00000, 1.00000, 0.00000, 0, 1, 0)]
    [InlineData(0.96422, 0.00000, 0.00000, 1, 0, 0.292064)]
    [InlineData(0.00000, 0.00000, 0.82521, 0, 0.181415, 1)]
    [InlineData(0, 0, 0, 0, 0, 0)]
    [InlineData(0.297676, 0.267854, 0.045504, 0.720315, 0.509999, 0.168112)]
    public void Convert_XYZ_D50_To_SRGB(float x, float y, float z, float r, float g, float b)
    {
        // Arrange
        CieXyz input = new(x, y, z);
        ColorConversionOptions options = new() { SourceWhitePoint = KnownIlluminants.D50, TargetRgbWorkingSpace = KnownRgbWorkingSpaces.SRgb };
        ColorProfileConverter converter = new(options);
        Rgb expected = new(r, g, b);

        Span<CieXyz> inputSpan = new CieXyz[5];
        inputSpan.Fill(input);

        Span<Rgb> actualSpan = new Rgb[5];

        // Act
        Rgb actual = converter.Convert<CieXyz, Rgb>(input);
        converter.Convert<CieXyz, Rgb>(inputSpan, actualSpan);

        // Assert
        Assert.Equal(expected, actual, Comparer);

        for (int i = 0; i < actualSpan.Length; i++)
        {
            Assert.Equal(expected, actualSpan[i], Comparer);
        }
    }

    [Theory]
    [InlineData(0.950470, 1.000000, 1.088830, 1, 1, 1)]
    [InlineData(0, 1.000000, 0, 0, 1, 0)]
    [InlineData(0.950470, 0, 0, 1, 0, 0.254967)]
    [InlineData(0, 0, 1.088830, 0, 0.235458, 1)]
    [InlineData(0, 0, 0, 0, 0, 0)]
    [InlineData(0.297676, 0.267854, 0.045504, 0.754903, 0.501961, 0.099998)]
    public void Convert_XYZ_D65_To_SRGB(float x, float y, float z, float r, float g, float b)
    {
        // Arrange
        CieXyz input = new(x, y, z);
        ColorConversionOptions options = new() { SourceWhitePoint = KnownIlluminants.D65, TargetRgbWorkingSpace = KnownRgbWorkingSpaces.SRgb };
        ColorProfileConverter converter = new(options);
        Rgb expected = new(r, g, b);

        Span<CieXyz> inputSpan = new CieXyz[5];
        inputSpan.Fill(input);

        Span<Rgb> actualSpan = new Rgb[5];

        // Act
        Rgb actual = converter.Convert<CieXyz, Rgb>(input);
        converter.Convert<CieXyz, Rgb>(inputSpan, actualSpan);

        // Assert
        Assert.Equal(expected, actual, Comparer);

        for (int i = 0; i < actualSpan.Length; i++)
        {
            Assert.Equal(expected, actualSpan[i], Comparer);
        }
    }

    [Theory]
    [InlineData(1, 1, 1, 0.964220, 1.000000, 0.825210)]
    [InlineData(0, 0, 0, 0, 0, 0)]
    [InlineData(1, 0, 0, 0.436075, 0.222504, 0.013932)]
    [InlineData(0, 1, 0, 0.385065, 0.716879, 0.0971045)]
    [InlineData(0, 0, 1, 0.143080, 0.060617, 0.714173)]
    [InlineData(0.754902, 0.501961, 0.100000, 0.315757, 0.273323, 0.035506)]
    public void Convert_SRGB_To_XYZ_D50(float r, float g, float b, float x, float y, float z)
    {
        // Arrange
        Rgb input = new(r, g, b);
        ColorConversionOptions options = new() { TargetWhitePoint = KnownIlluminants.D50, SourceRgbWorkingSpace = KnownRgbWorkingSpaces.SRgb };
        ColorProfileConverter converter = new(options);
        CieXyz expected = new(x, y, z);

        Span<Rgb> inputSpan = new Rgb[5];
        inputSpan.Fill(input);

        Span<CieXyz> actualSpan = new CieXyz[5];

        // Act
        CieXyz actual = converter.Convert<Rgb, CieXyz>(input);
        converter.Convert<Rgb, 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(1, 1, 1, 0.950470, 1.000000, 1.088830)]
    [InlineData(0, 0, 0, 0, 0, 0)]
    [InlineData(1, 0, 0, 0.412456, 0.212673, 0.019334)]
    [InlineData(0, 1, 0, 0.357576, 0.715152, 0.119192)]
    [InlineData(0, 0, 1, 0.1804375, 0.072175, 0.950304)]
    [InlineData(0.754902, 0.501961, 0.100000, 0.297676, 0.267854, 0.045504)]
    public void Convert_SRGB_To_XYZ_D65(float r, float g, float b, float x, float y, float z)
    {
        // Arrange
        Rgb input = new(r, g, b);
        ColorConversionOptions options = new() { TargetWhitePoint = KnownIlluminants.D65, SourceRgbWorkingSpace = KnownRgbWorkingSpaces.SRgb };
        ColorProfileConverter converter = new(options);
        CieXyz expected = new(x, y, z);

        Span<Rgb> inputSpan = new Rgb[5];
        inputSpan.Fill(input);

        Span<CieXyz> actualSpan = new CieXyz[5];

        // Act
        CieXyz actual = converter.Convert<Rgb, CieXyz>(input);
        converter.Convert<Rgb, CieXyz>(inputSpan, actualSpan);

        // Assert
        Assert.Equal(expected, actual, Comparer);

        for (int i = 0; i < actualSpan.Length; i++)
        {
            Assert.Equal(expected, actualSpan[i], Comparer);
        }
    }
}