Pass ColorSpace types by readonly ref

src/ImageSharp/ColorSpaces/Conversion/IColorConversion.cs

@@ -8,13 +8,15 @@ namespace SixLabors.ImageSharp.ColorSpaces.Conversion
     /// </summary>
     /// <typeparam name="T">The input color type.</typeparam>
     /// <typeparam name="TResult">The result color type.</typeparam>
-    internal interface IColorConversion<in T, out TResult>
+    internal interface IColorConversion<T, TResult>
+        where T: struct
+        where TResult: struct
     {
         /// <summary>
         /// Performs the conversion from the input to an instance of the output type.
         /// </summary>
         /// <param name="input">The input color instance.</param>
         /// <returns>The converted result</returns>
-        TResult Convert(T input);
+        TResult Convert(in T input);
     }
 }

src/ImageSharp/ColorSpaces/Conversion/Implementation/CieLab/CieLabToCieXyzConverter.cs

@@ -13,7 +13,7 @@ namespace SixLabors.ImageSharp.ColorSpaces.Conversion.Implementation.CieLabColor
     {
         /// <inheritdoc/>
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        public CieXyz Convert(CieLab input)
+        public CieXyz Convert(in CieLab input)
         {
             DebugGuard.NotNull(input, nameof(input));
 

src/ImageSharp/ColorSpaces/Conversion/Implementation/CieLab/CieXyzToCieLabConverter.cs

@@ -26,7 +26,7 @@ namespace SixLabors.ImageSharp.ColorSpaces.Conversion.Implementation.CieLabColor
         /// </summary>
         /// <param name="labWhitePoint">The target reference lab white point</param>
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        public CieXyzToCieLabConverter(CieXyz labWhitePoint)
+        public CieXyzToCieLabConverter(in CieXyz labWhitePoint)
         {
             this.LabWhitePoint = labWhitePoint;
         }
@@ -42,7 +42,7 @@ namespace SixLabors.ImageSharp.ColorSpaces.Conversion.Implementation.CieLabColor
 
         /// <inheritdoc />
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        public CieLab Convert(CieXyz input)
+        public CieLab Convert(in CieXyz input)
         {
             DebugGuard.NotNull(input, nameof(input));
 

src/ImageSharp/ColorSpaces/Conversion/Implementation/CieLch/CIeLchToCieLabConverter.cs

@@ -14,7 +14,7 @@ namespace SixLabors.ImageSharp.ColorSpaces.Conversion.Implementation.CieLchColor
     {
         /// <inheritdoc/>
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        public CieLab Convert(CieLch input)
+        public CieLab Convert(in CieLch input)
         {
             DebugGuard.NotNull(input, nameof(input));
 

src/ImageSharp/ColorSpaces/Conversion/Implementation/CieLch/CieLabToCieLchConverter.cs

@@ -14,7 +14,7 @@ namespace SixLabors.ImageSharp.ColorSpaces.Conversion.Implementation.CieLchColor
     {
         /// <inheritdoc/>
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        public CieLch Convert(CieLab input)
+        public CieLch Convert(in CieLab input)
         {
             DebugGuard.NotNull(input, nameof(input));
 

src/ImageSharp/ColorSpaces/Conversion/Implementation/CieLchuv/CieLchuvToCieLuvConverter.cs

@@ -3,7 +3,6 @@
 
 using System;
 using System.Runtime.CompilerServices;
-using SixLabors.ImageSharp.ColorSpaces;
 
 namespace SixLabors.ImageSharp.ColorSpaces.Conversion.Implementation.CieLchuvColorSapce
 {
@@ -14,7 +13,7 @@ namespace SixLabors.ImageSharp.ColorSpaces.Conversion.Implementation.CieLchuvCol
     {
         /// <inheritdoc/>
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        public CieLuv Convert(CieLchuv input)
+        public CieLuv Convert(in CieLchuv input)
         {
             DebugGuard.NotNull(input, nameof(input));
 

src/ImageSharp/ColorSpaces/Conversion/Implementation/CieLchuv/CieLuvToCieLchuvConverter.cs

@@ -14,7 +14,7 @@ namespace SixLabors.ImageSharp.ColorSpaces.Conversion.Implementation.CieLchuvCol
     {
         /// <inheritdoc/>
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        public CieLchuv Convert(CieLuv input)
+        public CieLchuv Convert(in CieLuv input)
         {
             DebugGuard.NotNull(input, nameof(input));
 

src/ImageSharp/ColorSpaces/Conversion/Implementation/CieLuv/CieLuvToCieXyzConverter.cs

@@ -3,7 +3,6 @@
 
 using System;
 using System.Runtime.CompilerServices;
-using SixLabors.ImageSharp.ColorSpaces;
 
 namespace SixLabors.ImageSharp.ColorSpaces.Conversion.Implementation.CieLuvColorSapce
 {
@@ -14,7 +13,7 @@ namespace SixLabors.ImageSharp.ColorSpaces.Conversion.Implementation.CieLuvColor
     {
         /// <inheritdoc/>
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        public CieXyz Convert(CieLuv input)
+        public CieXyz Convert(in CieLuv input)
         {
             DebugGuard.NotNull(input, nameof(input));
 

src/ImageSharp/ColorSpaces/Conversion/Implementation/CieLuv/CieXyzToCieLuvConverter.cs

@@ -26,7 +26,7 @@ namespace SixLabors.ImageSharp.ColorSpaces.Conversion.Implementation.CieLuvColor
         /// </summary>
         /// <param name="luvWhitePoint">The target reference luv white point</param>
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        public CieXyzToCieLuvConverter(CieXyz luvWhitePoint)
+        public CieXyzToCieLuvConverter(in CieXyz luvWhitePoint)
         {
             this.LuvWhitePoint = luvWhitePoint;
         }
@@ -42,7 +42,7 @@ namespace SixLabors.ImageSharp.ColorSpaces.Conversion.Implementation.CieLuvColor
 
         /// <inheritdoc />
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        public CieLuv Convert(CieXyz input)
+        public CieLuv Convert(in CieXyz input)
         {
             DebugGuard.NotNull(input, nameof(input));
 

src/ImageSharp/ColorSpaces/Conversion/Implementation/CieXyy/CieXyzAndCieXyyConverter.cs

@@ -15,7 +15,7 @@ namespace SixLabors.ImageSharp.ColorSpaces.Conversion.Implementation.CieXyyColor
     {
         /// <inheritdoc/>
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        public CieXyy Convert(CieXyz input)
+        public CieXyy Convert(in CieXyz input)
         {
             DebugGuard.NotNull(input, nameof(input));
 
@@ -32,7 +32,7 @@ namespace SixLabors.ImageSharp.ColorSpaces.Conversion.Implementation.CieXyyColor
 
         /// <inheritdoc/>
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        public CieXyz Convert(CieXyy input)
+        public CieXyz Convert(in CieXyy input)
         {
             DebugGuard.NotNull(input, nameof(input));
 

src/ImageSharp/ColorSpaces/Conversion/Implementation/Cmyk/CmykAndRgbConverter.cs

@@ -14,7 +14,7 @@ namespace SixLabors.ImageSharp.ColorSpaces.Conversion.Implementation.CmykColorSa
     {
         /// <inheritdoc/>
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        public Rgb Convert(Cmyk input)
+        public Rgb Convert(in Cmyk input)
         {
             float r = (1F - input.C) * (1F - input.K);
             float g = (1F - input.M) * (1F - input.K);
@@ -25,7 +25,7 @@ namespace SixLabors.ImageSharp.ColorSpaces.Conversion.Implementation.CmykColorSa
 
         /// <inheritdoc/>
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        public Cmyk Convert(Rgb input)
+        public Cmyk Convert(in Rgb input)
         {
             // To CMYK
             float c = 1F - input.R;

src/ImageSharp/ColorSpaces/Conversion/Implementation/Hsl/HslAndRgbConverter.cs

@@ -15,7 +15,7 @@ namespace SixLabors.ImageSharp.ColorSpaces.Conversion.Implementation.HslColorSap
     {
         /// <inheritdoc/>
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        public Rgb Convert(Hsl input)
+        public Rgb Convert(in Hsl input)
         {
             DebugGuard.NotNull(input, nameof(input));
 
@@ -48,7 +48,7 @@ namespace SixLabors.ImageSharp.ColorSpaces.Conversion.Implementation.HslColorSap
 
         /// <inheritdoc/>
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        public Hsl Convert(Rgb input)
+        public Hsl Convert(in Rgb input)
         {
             DebugGuard.NotNull(input, nameof(input));
 

src/ImageSharp/ColorSpaces/Conversion/Implementation/Hsv/HsvAndRgbConverter.cs

@@ -3,7 +3,6 @@
 
 using System;
 using System.Runtime.CompilerServices;
-using SixLabors.ImageSharp.ColorSpaces;
 
 namespace SixLabors.ImageSharp.ColorSpaces.Conversion.Implementation.HsvColorSapce
 {
@@ -15,7 +14,7 @@ namespace SixLabors.ImageSharp.ColorSpaces.Conversion.Implementation.HsvColorSap
     {
         /// <inheritdoc/>
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        public Rgb Convert(Hsv input)
+        public Rgb Convert(in Hsv input)
         {
             DebugGuard.NotNull(input, nameof(input));
 
@@ -80,7 +79,7 @@ namespace SixLabors.ImageSharp.ColorSpaces.Conversion.Implementation.HsvColorSap
 
         /// <inheritdoc/>
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        public Hsv Convert(Rgb input)
+        public Hsv Convert(in Rgb input)
         {
             DebugGuard.NotNull(input, nameof(input));
 

src/ImageSharp/ColorSpaces/Conversion/Implementation/HunterLab/CieXyzToHunterLabConverter.cs

@@ -26,7 +26,7 @@ namespace SixLabors.ImageSharp.ColorSpaces.Conversion.Implementation.HunterLabCo
         /// </summary>
         /// <param name="labWhitePoint">The hunter Lab white point.</param>
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        public CieXyzToHunterLabConverter(CieXyz labWhitePoint)
+        public CieXyzToHunterLabConverter(in CieXyz labWhitePoint)
         {
             this.HunterLabWhitePoint = labWhitePoint;
         }
@@ -42,7 +42,7 @@ namespace SixLabors.ImageSharp.ColorSpaces.Conversion.Implementation.HunterLabCo
 
         /// <inheritdoc/>
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        public HunterLab Convert(CieXyz input)
+        public HunterLab Convert(in CieXyz input)
         {
             DebugGuard.NotNull(input, nameof(input));
 

src/ImageSharp/ColorSpaces/Conversion/Implementation/HunterLab/HunterLabToCieXyzConverter.cs

@@ -14,7 +14,7 @@ namespace SixLabors.ImageSharp.ColorSpaces.Conversion.Implementation.HunterLabCo
     {
         /// <inheritdoc/>
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        public CieXyz Convert(HunterLab input)
+        public CieXyz Convert(in HunterLab input)
         {
             DebugGuard.NotNull(input, nameof(input));
 

src/ImageSharp/ColorSpaces/Conversion/Implementation/Lms/CieXyzAndLmsConverter.cs

@@ -3,7 +3,6 @@
 
 using System.Numerics;
 using System.Runtime.CompilerServices;
-using SixLabors.ImageSharp.ColorSpaces;
 
 namespace SixLabors.ImageSharp.ColorSpaces.Conversion.Implementation.LmsColorSapce
 {
@@ -61,7 +60,7 @@ namespace SixLabors.ImageSharp.ColorSpaces.Conversion.Implementation.LmsColorSap
 
         /// <inheritdoc/>
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        public Lms Convert(CieXyz input)
+        public Lms Convert(in CieXyz input)
         {
             DebugGuard.NotNull(input, nameof(input));
 
@@ -71,7 +70,7 @@ namespace SixLabors.ImageSharp.ColorSpaces.Conversion.Implementation.LmsColorSap
 
         /// <inheritdoc/>
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        public CieXyz Convert(Lms input)
+        public CieXyz Convert(in Lms input)
         {
             DebugGuard.NotNull(input, nameof(input));
 

src/ImageSharp/ColorSpaces/Conversion/Implementation/Rgb/CieXyzToLinearRgbConverter.cs

@@ -36,7 +36,7 @@ namespace SixLabors.ImageSharp.ColorSpaces.Conversion.Implementation.RgbColorSap
         public IRgbWorkingSpace TargetWorkingSpace { get; }
 
         /// <inheritdoc/>
-        public LinearRgb Convert(CieXyz input)
+        public LinearRgb Convert(in CieXyz input)
         {
             DebugGuard.NotNull(input, nameof(input));
 

src/ImageSharp/ColorSpaces/Conversion/Implementation/Rgb/LinearRgbToCieXyzConverter.cs

@@ -36,7 +36,7 @@ namespace SixLabors.ImageSharp.ColorSpaces.Conversion.Implementation.RgbColorSap
         public IRgbWorkingSpace SourceWorkingSpace { get; }
 
         /// <inheritdoc/>
-        public CieXyz Convert(LinearRgb input)
+        public CieXyz Convert(in LinearRgb input)
         {
             DebugGuard.NotNull(input, nameof(input));
             DebugGuard.IsTrue(input.WorkingSpace.Equals(this.SourceWorkingSpace), nameof(input.WorkingSpace), "Input and source working spaces must be equal.");

src/ImageSharp/ColorSpaces/Conversion/Implementation/Rgb/LinearRgbToRgbConverter.cs

@@ -11,7 +11,7 @@ namespace SixLabors.ImageSharp.ColorSpaces.Conversion.Implementation.RgbColorSap
     internal class LinearRgbToRgbConverter : IColorConversion<LinearRgb, Rgb>
     {
         /// <inheritdoc/>
-        public Rgb Convert(LinearRgb input)
+        public Rgb Convert(in LinearRgb input)
         {
             DebugGuard.NotNull(input, nameof(input));
 

src/ImageSharp/ColorSpaces/Conversion/Implementation/Rgb/RgbToLinearRgbConverter.cs

@@ -11,7 +11,7 @@ namespace SixLabors.ImageSharp.ColorSpaces.Conversion.Implementation.RgbColorSap
     internal class RgbToLinearRgbConverter : IColorConversion<Rgb, LinearRgb>
     {
         /// <inheritdoc/>
-        public LinearRgb Convert(Rgb input)
+        public LinearRgb Convert(in Rgb input)
         {
             Guard.NotNull(input, nameof(input));
 

src/ImageSharp/ColorSpaces/Conversion/Implementation/YCbCr/YCbCrAndRgbConverter.cs

@@ -4,7 +4,6 @@
 using System;
 using System.Numerics;
 using System.Runtime.CompilerServices;
-using SixLabors.ImageSharp.ColorSpaces;
 
 namespace SixLabors.ImageSharp.ColorSpaces.Conversion.Implementation.YCbCrColorSapce
 {
@@ -18,7 +17,7 @@ namespace SixLabors.ImageSharp.ColorSpaces.Conversion.Implementation.YCbCrColorS
 
         /// <inheritdoc/>
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        public Rgb Convert(YCbCr input)
+        public Rgb Convert(in YCbCr input)
         {
             DebugGuard.NotNull(input, nameof(input));
 
@@ -35,7 +34,7 @@ namespace SixLabors.ImageSharp.ColorSpaces.Conversion.Implementation.YCbCrColorS
 
         /// <inheritdoc/>
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        public YCbCr Convert(Rgb input)
+        public YCbCr Convert(in Rgb input)
         {
             DebugGuard.NotNull(input, nameof(input));