Create Hsl.cs

Author: JimBobSquarePants

src/ImageSharp/ColorProfiles/Hsl.cs

@@ -0,0 +1,243 @@
+// Copyright (c) Six Labors.
+// Licensed under the Six Labors Split License.
+
+using System.Numerics;
+using System.Runtime.CompilerServices;
+
+namespace SixLabors.ImageSharp.ColorProfiles;
+
+/// <summary>
+/// Represents a Hsl (hue, saturation, lightness) color.
+/// </summary>
+public readonly struct Hsl : IColorProfile<Hsl, Rgb>
+{
+    private static readonly Vector3 Min = Vector3.Zero;
+    private static readonly Vector3 Max = new(360, 1, 1);
+
+    /// <summary>
+    /// Initializes a new instance of the <see cref="Hsl"/> struct.
+    /// </summary>
+    /// <param name="h">The h hue component.</param>
+    /// <param name="s">The s saturation component.</param>
+    /// <param name="l">The l value (lightness) component.</param>
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    public Hsl(float h, float s, float l)
+        : this(new Vector3(h, s, l))
+    {
+    }
+
+    /// <summary>
+    /// Initializes a new instance of the <see cref="Hsl"/> struct.
+    /// </summary>
+    /// <param name="vector">The vector representing the h, s, l components.</param>
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    public Hsl(Vector3 vector)
+    {
+        vector = Vector3.Clamp(vector, Min, Max);
+        this.H = vector.X;
+        this.S = vector.Y;
+        this.L = vector.Z;
+    }
+
+    /// <summary>
+    /// Gets the hue component.
+    /// <remarks>A value ranging between 0 and 360.</remarks>
+    /// </summary>
+    public readonly float H { get; }
+
+    /// <summary>
+    /// Gets the saturation component.
+    /// <remarks>A value ranging between 0 and 1.</remarks>
+    /// </summary>
+    public readonly float S { get; }
+
+    /// <summary>
+    /// Gets the lightness component.
+    /// <remarks>A value ranging between 0 and 1.</remarks>
+    /// </summary>
+    public readonly float L { get; }
+
+    /// <summary>
+    /// Compares two <see cref="Hsl"/> objects for equality.
+    /// </summary>
+    /// <param name="left">
+    /// The <see cref="Hsl"/> on the left side of the operand.
+    /// </param>
+    /// <param name="right">The <see cref="Hsl"/> on the right side of the operand.</param>
+    /// <returns>
+    /// True if the current left is equal to the <paramref name="right"/> parameter; otherwise, false.
+    /// </returns>
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    public static bool operator ==(Hsl left, Hsl right) => left.Equals(right);
+
+    /// <summary>
+    /// Compares two <see cref="Hsl"/> objects for inequality.
+    /// </summary>
+    /// <param name="left">The <see cref="Hsl"/> on the left side of the operand.</param>
+    /// <param name="right">The <see cref="Hsl"/> on the right side of the operand.</param>
+    /// <returns>
+    /// True if the current left is unequal to the <paramref name="right"/> parameter; otherwise, false.
+    /// </returns>
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    public static bool operator !=(Hsl left, Hsl right) => !left.Equals(right);
+
+    /// <inheritdoc/>
+    public static Hsl FromProfileConnectingSpace(ColorConversionOptions options, in Rgb source)
+    {
+        float r = source.R;
+        float g = source.G;
+        float b = source.B;
+
+        float max = MathF.Max(r, MathF.Max(g, b));
+        float min = MathF.Min(r, MathF.Min(g, b));
+        float chroma = max - min;
+        float h = 0F;
+        float s = 0F;
+        float l = (max + min) / 2F;
+
+        if (MathF.Abs(chroma) < Constants.Epsilon)
+        {
+            return new Hsl(0F, s, l);
+        }
+
+        if (MathF.Abs(r - max) < Constants.Epsilon)
+        {
+            h = (g - b) / chroma;
+        }
+        else if (MathF.Abs(g - max) < Constants.Epsilon)
+        {
+            h = 2F + ((b - r) / chroma);
+        }
+        else if (MathF.Abs(b - max) < Constants.Epsilon)
+        {
+            h = 4F + ((r - g) / chroma);
+        }
+
+        h *= 60F;
+        if (h < 0F)
+        {
+            h += 360F;
+        }
+
+        if (l <= .5F)
+        {
+            s = chroma / (max + min);
+        }
+        else
+        {
+            s = chroma / (2F - max - min);
+        }
+
+        return new Hsl(h, s, l);
+    }
+
+    /// <inheritdoc/>
+    public static void FromProfileConnectionSpace(ColorConversionOptions options, ReadOnlySpan<Rgb> source, Span<Hsl> destination)
+    {
+        Guard.DestinationShouldNotBeTooShort(source, destination, nameof(destination));
+        for (int i = 0; i < source.Length; i++)
+        {
+            Rgb rgb = source[i];
+            destination[i] = FromProfileConnectingSpace(options, in rgb);
+        }
+    }
+
+    /// <inheritdoc/>
+    public Rgb ToProfileConnectingSpace(ColorConversionOptions options)
+    {
+        float rangedH = this.H / 360F;
+        float r = 0;
+        float g = 0;
+        float b = 0;
+        float s = this.S;
+        float l = this.L;
+
+        if (MathF.Abs(l) > Constants.Epsilon)
+        {
+            if (MathF.Abs(s) < Constants.Epsilon)
+            {
+                r = g = b = l;
+            }
+            else
+            {
+                float temp2 = (l < .5F) ? l * (1F + s) : l + s - (l * s);
+                float temp1 = (2F * l) - temp2;
+
+                r = GetColorComponent(temp1, temp2, rangedH + 0.3333333F);
+                g = GetColorComponent(temp1, temp2, rangedH);
+                b = GetColorComponent(temp1, temp2, rangedH - 0.3333333F);
+            }
+        }
+
+        return new Rgb(r, g, b);
+    }
+
+    /// <inheritdoc/>
+    public static void ToProfileConnectionSpace(ColorConversionOptions options, ReadOnlySpan<Hsl> source, Span<Rgb> destination)
+    {
+        Guard.DestinationShouldNotBeTooShort(source, destination, nameof(destination));
+        for (int i = 0; i < source.Length; i++)
+        {
+            Hsl hsl = source[i];
+            destination[i] = hsl.ToProfileConnectingSpace(options);
+        }
+    }
+
+    /// <inheritdoc/>
+    public static ChromaticAdaptionWhitePointSource GetChromaticAdaptionWhitePointSource()
+        => ChromaticAdaptionWhitePointSource.RgbWorkingSpace;
+
+    /// <inheritdoc/>
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    public override int GetHashCode() => HashCode.Combine(this.H, this.S, this.L);
+
+    /// <inheritdoc/>
+    public override string ToString() => FormattableString.Invariant($"Hsl({this.H:#0.##}, {this.S:#0.##}, {this.L:#0.##})");
+
+    /// <inheritdoc/>
+    public override bool Equals(object? obj) => obj is Hsl other && this.Equals(other);
+
+    /// <inheritdoc/>
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    public bool Equals(Hsl other)
+        => this.H.Equals(other.H)
+        && this.S.Equals(other.S)
+        && this.L.Equals(other.L);
+
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    private static float GetColorComponent(float first, float second, float third)
+    {
+        third = MoveIntoRange(third);
+        if (third < 0.1666667F)
+        {
+            return first + ((second - first) * 6F * third);
+        }
+
+        if (third < .5F)
+        {
+            return second;
+        }
+
+        if (third < 0.6666667F)
+        {
+            return first + ((second - first) * (0.6666667F - third) * 6F);
+        }
+
+        return first;
+    }
+
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    private static float MoveIntoRange(float value)
+    {
+        if (value < 0F)
+        {
+            value++;
+        }
+        else if (value > 1F)
+        {
+            value--;
+        }
+
+        return value;
+    }
+}