Add GammaToLinear and LinearToGamma (#60)

CHANGELOG.md

@@ -13,6 +13,8 @@
 - X10D: Added `Color.GetClosestConsoleColor()`
 - X10D: Added `DateTime.GetIso8601WeekOfYear()` and `DateTimeOffset.GetIso8601WeekOfYear()`
 - X10D: Added `DirectoryInfo.Clear()`
+- X10D: Added `double.LinearToGamma([gamma])` and `float.LinearToGamma([gamma])` (#60)
+- X10D: Added `double.GammaToLinear([gamma])` and `float.GammaToLinear([gamma])` (#60)
 - X10D: Added `GreatestCommonFactor` for built-in integer types
 - X10D: Added `IEnumerable<T>.CountWhereNot(Func<T, bool>)`
 - X10D: Added `IEnumerable<T>.FirstWhereNot(Func<T, bool>)`

X10D.Tests/src/Math/MathUtilityTests.cs

@@ -7,6 +7,26 @@ namespace X10D.Tests.Math;
 [TestClass]
 public class MathUtilityTests
 {
+    [TestMethod]
+    public void GammaToLinear_ShouldReturnQuarter_GivenQuarterAndGamma1()
+    {
+        double doubleResult = MathUtility.GammaToLinear(0.25, 1.0);
+        float floatResult = MathUtility.GammaToLinear(0.25f, 1.0f);
+
+        Assert.AreEqual(0.25, doubleResult);
+        Assert.AreEqual(0.25f, floatResult);
+    }
+
+    [TestMethod]
+    public void GammaToLinear_ShouldReturn1_Given1AndDefaultGamma()
+    {
+        double doubleResult = MathUtility.GammaToLinear(1.0);
+        float floatResult = MathUtility.GammaToLinear(1.0f);
+
+        Assert.AreEqual(1.0, doubleResult);
+        Assert.AreEqual(1.0f, floatResult);
+    }
+
     [TestMethod]
     public void InverseLerp_ShouldReturn0_5_Given0_5_0_1()
     {
@@ -43,4 +63,24 @@ public class MathUtilityTests
         Assert.AreEqual(0.0, doubleResult, 1e-6);
         Assert.AreEqual(0.0f, floatResult, 1e-6f);
     }
+
+    [TestMethod]
+    public void LinearToGamma_ShouldReturnQuarter_GivenQuarterAndGamma1()
+    {
+        double doubleResult = MathUtility.LinearToGamma(0.25, 1.0);
+        float floatResult = MathUtility.LinearToGamma(0.25f, 1.0f);
+
+        Assert.AreEqual(0.25, doubleResult);
+        Assert.AreEqual(0.25f, floatResult);
+    }
+
+    [TestMethod]
+    public void LinearToGamma_ShouldReturn1_Given1AndDefaultGamma()
+    {
+        double doubleResult = MathUtility.LinearToGamma(1.0);
+        float floatResult = MathUtility.LinearToGamma(1.0f);
+
+        Assert.AreEqual(1.0, doubleResult);
+        Assert.AreEqual(1.0f, floatResult);
+    }
 }

X10D/src/Math/MathUtility.cs

@@ -8,6 +8,75 @@ namespace X10D.Math;
 /// </summary>
 public static class MathUtility
 {
+    private const double DefaultGamma = 2.2;
+    private const float DefaultGammaF = 2.2f;
+
+    /// <summary>
+    ///     Converts a gamma-encoded value to a linear value using a gamma value of <c>2.2</c>.
+    /// </summary>
+    /// <param name="value">The gamma-encoded value to convert. Expected range is [0, 1].</param>
+    /// <returns>The linear value.</returns>
+    [Pure]
+#if NETSTANDARD2_1
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+#else
+    [MethodImpl(MethodImplOptions.AggressiveInlining | MethodImplOptions.AggressiveOptimization)]
+#endif
+    public static float GammaToLinear(float value)
+    {
+        return GammaToLinear(value, DefaultGammaF);
+    }
+
+    /// <summary>
+    ///     Converts a gamma-encoded value to a linear value using the specified gamma value.
+    /// </summary>
+    /// <param name="value">The gamma-encoded value to convert. Expected range is [0, 1].</param>
+    /// <param name="gamma">The gamma value to use for decoding.</param>
+    /// <returns>The linear value.</returns>
+    [Pure]
+#if NETSTANDARD2_1
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+#else
+    [MethodImpl(MethodImplOptions.AggressiveInlining | MethodImplOptions.AggressiveOptimization)]
+#endif
+    public static float GammaToLinear(float value, float gamma)
+    {
+        return MathF.Pow(value, 1.0f / gamma);
+    }
+
+    /// <summary>
+    ///     Converts a gamma-encoded value to a linear value using a gamma value of <c>2.2</c>.
+    /// </summary>
+    /// <param name="value">The gamma-encoded value to convert. Expected range is [0, 1].</param>
+    /// <returns>The linear value.</returns>
+    [Pure]
+#if NETSTANDARD2_1
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+#else
+    [MethodImpl(MethodImplOptions.AggressiveInlining | MethodImplOptions.AggressiveOptimization)]
+#endif
+    public static double GammaToLinear(double value)
+    {
+        return GammaToLinear(value, DefaultGamma);
+    }
+
+    /// <summary>
+    ///     Converts a gamma-encoded value to a linear value using the specified gamma value.
+    /// </summary>
+    /// <param name="value">The gamma-encoded value to convert. Expected range is [0, 1].</param>
+    /// <param name="gamma">The gamma value to use for decoding.</param>
+    /// <returns>The linear value.</returns>
+    [Pure]
+#if NETSTANDARD2_1
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+#else
+    [MethodImpl(MethodImplOptions.AggressiveInlining | MethodImplOptions.AggressiveOptimization)]
+#endif
+    public static double GammaToLinear(double value, double gamma)
+    {
+        return System.Math.Pow(value, 1.0 / gamma);
+    }
+
     /// <summary>
     ///     Returns the linear interpolation inverse of a value, such that it determines where a value lies between two other
     ///     values.
@@ -100,6 +169,72 @@ public static class MathUtility
         return ((1.0 - alpha) * value) + (alpha * target);
     }
 
+    /// <summary>
+    ///     Converts a linear value to a gamma-encoded value using a gamma value of <c>2.2</c>.
+    /// </summary>
+    /// <param name="value">The linear value to convert. Expected range is [0, 1].</param>
+    /// <returns>The gamma-encoded value.</returns>
+    [Pure]
+#if NETSTANDARD2_1
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+#else
+    [MethodImpl(MethodImplOptions.AggressiveInlining | MethodImplOptions.AggressiveOptimization)]
+#endif
+    public static float LinearToGamma(float value)
+    {
+        return LinearToGamma(value, DefaultGammaF);
+    }
+
+    /// <summary>
+    ///     Converts a linear value to a gamma-encoded value using the specified gamma value.
+    /// </summary>
+    /// <param name="value">The linear value to convert. Expected range is [0, 1].</param>
+    /// <param name="gamma">The gamma value to use for encoding.</param>
+    /// <returns>The gamma-encoded value.</returns>
+    [Pure]
+#if NETSTANDARD2_1
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+#else
+    [MethodImpl(MethodImplOptions.AggressiveInlining | MethodImplOptions.AggressiveOptimization)]
+#endif
+    public static float LinearToGamma(float value, float gamma)
+    {
+        return MathF.Pow(value, 1.0f / gamma);
+    }
+
+    /// <summary>
+    ///     Converts a linear value to a gamma-encoded value using a gamma value of <c>2.2</c>.
+    /// </summary>
+    /// <param name="value">The linear value to convert. Expected range is [0, 1].</param>
+    /// <returns>The gamma-encoded value.</returns>
+    [Pure]
+#if NETSTANDARD2_1
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+#else
+    [MethodImpl(MethodImplOptions.AggressiveInlining | MethodImplOptions.AggressiveOptimization)]
+#endif
+    public static double LinearToGamma(double value)
+    {
+        return LinearToGamma(value, DefaultGamma);
+    }
+
+    /// <summary>
+    ///     Converts a linear value to a gamma-encoded value using the specified gamma value.
+    /// </summary>
+    /// <param name="value">The linear value to convert. Expected range is [0, 1].</param>
+    /// <param name="gamma">The gamma value to use for encoding.</param>
+    /// <returns>The gamma-encoded value.</returns>
+    [Pure]
+#if NETSTANDARD2_1
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+#else
+    [MethodImpl(MethodImplOptions.AggressiveInlining | MethodImplOptions.AggressiveOptimization)]
+#endif
+    public static double LinearToGamma(double value, double gamma)
+    {
+        return System.Math.Pow(value, 1.0 / gamma);
+    }
+
     /// <summary>
     ///     Converts a value from being a percentage of one range, to being the same percentage in a new range.
     /// </summary>