mirror of
https://github.com/oliverbooth/X10D
synced 2024-11-25 11:58:48 +00:00
feat: add generic math where possible in MathUtility
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@ -1,6 +1,5 @@
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#if NET7_0_OR_GREATER
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using System.Diagnostics.Contracts;
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using System.Globalization;
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using System.Numerics;
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using System.Runtime.CompilerServices;
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using X10D.CompilerServices;
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@ -31,28 +30,5 @@ public static class BinaryIntegerExtensions
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TInteger root = TInteger.Abs(value).Mod(nine);
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return int.CreateChecked(root == TInteger.Zero ? nine : root);
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}
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/// <summary>
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/// Performs a modulo operation which supports a negative dividend.
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/// </summary>
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/// <param name="dividend">The dividend.</param>
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/// <param name="divisor">The divisor.</param>
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/// <returns>The result of <c>dividend mod divisor</c>.</returns>
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/// <remarks>
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/// The <c>%</c> operator (commonly called the modulo operator) in C# is not defined to be modulo, but is instead
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/// remainder. This quirk inherently makes it difficult to use modulo in a negative context, as <c>x % y</c> where x is
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/// negative will return a negative value, akin to <c>-(x % y)</c>, even if precedence is forced. This method provides a
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/// modulo operation which supports negative dividends.
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/// </remarks>
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/// <author>ShreevatsaR, https://stackoverflow.com/a/1082938/1467293</author>
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/// <license>CC-BY-SA 2.5</license>
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[Pure]
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[MethodImpl(CompilerResources.MethodImplOptions)]
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public static TInteger Mod<TInteger>(this TInteger dividend, TInteger divisor)
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where TInteger : IBinaryInteger<TInteger>
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{
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TInteger r = dividend % divisor;
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return r < TInteger.Zero ? r + divisor : r;
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}
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}
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#endif
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@ -1,4 +1,5 @@
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using System.Diagnostics.Contracts;
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using System.Numerics;
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using System.Runtime.CompilerServices;
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using X10D.CompilerServices;
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@ -12,6 +13,7 @@ public static class MathUtility
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private const double DefaultGamma = 2.2;
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private const float DefaultGammaF = 2.2f;
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#if !NET7_0_OR_GREATER
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/// <summary>
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/// Applies a simple bias function to value.
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/// </summary>
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@ -40,80 +42,6 @@ public static class MathUtility
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return value / ((1.0 / bias - 2.0) * (1.0 - value) + 1.0);
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}
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/// <summary>
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/// Calculates exponential decay for a value.
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/// </summary>
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/// <param name="value">The value to decay.</param>
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/// <param name="alpha">A factor by which to scale the decay.</param>
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/// <param name="decay">The decay amount.</param>
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/// <returns>The exponentially decayed value.</returns>
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public static float ExponentialDecay(float value, float alpha, float decay)
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{
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return value * MathF.Exp(-decay * alpha);
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}
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/// <summary>
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/// Calculates exponential decay for a value.
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/// </summary>
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/// <param name="value">The value to decay.</param>
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/// <param name="alpha">A factor by which to scale the decay.</param>
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/// <param name="decay">The decay amount.</param>
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/// <returns>The exponentially decayed value.</returns>
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public static double ExponentialDecay(double value, double alpha, double decay)
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{
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return value * System.Math.Exp(-decay * alpha);
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}
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/// <summary>
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/// Converts a gamma-encoded value to a linear value using a gamma value of <c>2.2</c>.
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/// </summary>
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/// <param name="value">The gamma-encoded value to convert. Expected range is [0, 1].</param>
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/// <returns>The linear value.</returns>
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[Pure]
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[MethodImpl(CompilerResources.MethodImplOptions)]
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public static float GammaToLinear(float value)
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{
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return GammaToLinear(value, DefaultGammaF);
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}
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/// <summary>
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/// Converts a gamma-encoded value to a linear value using the specified gamma value.
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/// </summary>
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/// <param name="value">The gamma-encoded value to convert. Expected range is [0, 1].</param>
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/// <param name="gamma">The gamma value to use for decoding.</param>
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/// <returns>The linear value.</returns>
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[Pure]
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[MethodImpl(CompilerResources.MethodImplOptions)]
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public static float GammaToLinear(float value, float gamma)
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{
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return MathF.Pow(value, 1.0f / gamma);
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}
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/// <summary>
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/// Converts a gamma-encoded value to a linear value using a gamma value of <c>2.2</c>.
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/// </summary>
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/// <param name="value">The gamma-encoded value to convert. Expected range is [0, 1].</param>
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/// <returns>The linear value.</returns>
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[Pure]
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[MethodImpl(CompilerResources.MethodImplOptions)]
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public static double GammaToLinear(double value)
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{
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return GammaToLinear(value, DefaultGamma);
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}
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/// <summary>
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/// Converts a gamma-encoded value to a linear value using the specified gamma value.
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/// </summary>
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/// <param name="value">The gamma-encoded value to convert. Expected range is [0, 1].</param>
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/// <param name="gamma">The gamma value to use for decoding.</param>
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/// <returns>The linear value.</returns>
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[Pure]
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[MethodImpl(CompilerResources.MethodImplOptions)]
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public static double GammaToLinear(double value, double gamma)
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{
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return System.Math.Pow(value, 1.0 / gamma);
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}
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/// <summary>
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/// Returns the linear interpolation inverse of a value, such that it determines where a value lies between two other
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/// values.
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@ -190,6 +118,167 @@ public static class MathUtility
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return ((1.0 - alpha) * value) + (alpha * target);
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}
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/// <summary>
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/// Performs smooth Hermite interpolation from one value to a target using a specified alpha.
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/// </summary>
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/// <param name="value">The interpolation source.</param>
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/// <param name="target">The interpolation target.</param>
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/// <param name="alpha">The interpolation alpha.</param>
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/// <returns>The interpolation result.</returns>
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public static float SmoothStep(float value, float target, float alpha)
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{
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alpha = System.Math.Clamp(alpha, 0.0f, 1.0f);
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alpha = -2.0f * alpha * alpha * alpha + 3.0f * alpha * alpha;
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return target * alpha + value * (1.0f - alpha);
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}
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/// <summary>
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/// Performs smooth Hermite interpolation from one value to a target using a specified alpha.
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/// </summary>
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/// <param name="value">The interpolation source.</param>
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/// <param name="target">The interpolation target.</param>
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/// <param name="alpha">The interpolation alpha.</param>
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/// <returns>The interpolation result.</returns>
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public static double SmoothStep(double value, double target, double alpha)
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{
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alpha = System.Math.Clamp(alpha, 0.0, 1.0);
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alpha = -2.0 * alpha * alpha * alpha + 3.0 * alpha * alpha;
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return target * alpha + value * (1.0 - alpha);
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}
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/// <summary>
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/// Converts a value from being a percentage of one range, to being the same percentage in a new range.
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/// </summary>
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/// <param name="value">The value to convert.</param>
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/// <param name="oldMin">The old minimum value.</param>
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/// <param name="oldMax">The old maximum value.</param>
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/// <param name="newMin">The new minimum value.</param>
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/// <param name="newMax">The new maximum value.</param>
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/// <returns>The scaled value.</returns>
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[Pure]
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[MethodImpl(CompilerResources.MethodImplOptions)]
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public static float ScaleRange(float value, float oldMin, float oldMax, float newMin, float newMax)
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{
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float oldRange = oldMax - oldMin;
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float newRange = newMax - newMin;
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float alpha = (value - oldMin) / oldRange;
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return (alpha * newRange) + newMin;
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}
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/// <summary>
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/// Converts a value from being a percentage of one range, to being the same percentage in a new range.
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/// </summary>
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/// <param name="value">The value to convert.</param>
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/// <param name="oldMin">The old minimum value.</param>
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/// <param name="oldMax">The old maximum value.</param>
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/// <param name="newMin">The new minimum value.</param>
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/// <param name="newMax">The new maximum value.</param>
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/// <returns>The scaled value.</returns>
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[Pure]
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[MethodImpl(CompilerResources.MethodImplOptions)]
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public static double ScaleRange(double value, double oldMin, double oldMax, double newMin, double newMax)
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{
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double oldRange = oldMax - oldMin;
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double newRange = newMax - newMin;
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double alpha = (value - oldMin) / oldRange;
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return (alpha * newRange) + newMin;
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}
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/// <summary>
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/// Returns the incremental sawtooth wave of a given value.
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/// </summary>
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/// <param name="value">The value to calculate.</param>
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/// <returns>The sawtooth wave of the given value.</returns>
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public static float Sawtooth(float value)
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{
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return (value - MathF.Floor(value));
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}
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/// <summary>
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/// Returns the incremental sawtooth wave of a given value.
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/// </summary>
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/// <param name="value">The value to calculate.</param>
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/// <returns>The sawtooth wave of the given value.</returns>
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public static double Sawtooth(double value)
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{
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return (value - System.Math.Floor(value));
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}
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#endif
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/// <summary>
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/// Calculates exponential decay for a value.
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/// </summary>
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/// <param name="value">The value to decay.</param>
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/// <param name="alpha">A factor by which to scale the decay.</param>
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/// <param name="decay">The decay amount.</param>
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/// <returns>The exponentially decayed value.</returns>
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public static float ExponentialDecay(float value, float alpha, float decay)
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{
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return value * MathF.Exp(-decay * alpha);
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}
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/// <summary>
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/// Calculates exponential decay for a value.
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/// </summary>
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/// <param name="value">The value to decay.</param>
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/// <param name="alpha">A factor by which to scale the decay.</param>
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/// <param name="decay">The decay amount.</param>
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/// <returns>The exponentially decayed value.</returns>
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public static double ExponentialDecay(double value, double alpha, double decay)
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{
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return value * System.Math.Exp(-decay * alpha);
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}
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/// <summary>
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/// Converts a gamma-encoded value to a linear value using a gamma value of <c>2.2</c>.
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/// </summary>
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/// <param name="value">The gamma-encoded value to convert. Expected range is [0, 1].</param>
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/// <returns>The linear value.</returns>
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[Pure]
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[MethodImpl(CompilerResources.MethodImplOptions)]
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public static float GammaToLinear(float value)
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{
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return GammaToLinear(value, DefaultGammaF);
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}
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/// <summary>
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/// Converts a gamma-encoded value to a linear value using the specified gamma value.
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/// </summary>
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/// <param name="value">The gamma-encoded value to convert. Expected range is [0, 1].</param>
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/// <param name="gamma">The gamma value to use for decoding.</param>
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/// <returns>The linear value.</returns>
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[Pure]
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[MethodImpl(CompilerResources.MethodImplOptions)]
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public static float GammaToLinear(float value, float gamma)
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{
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return MathF.Pow(value, 1.0f / gamma);
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}
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/// <summary>
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/// Converts a gamma-encoded value to a linear value using a gamma value of <c>2.2</c>.
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/// </summary>
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/// <param name="value">The gamma-encoded value to convert. Expected range is [0, 1].</param>
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/// <returns>The linear value.</returns>
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[Pure]
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[MethodImpl(CompilerResources.MethodImplOptions)]
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public static double GammaToLinear(double value)
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{
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return GammaToLinear(value, DefaultGamma);
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}
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/// <summary>
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/// Converts a gamma-encoded value to a linear value using the specified gamma value.
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/// </summary>
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/// <param name="value">The gamma-encoded value to convert. Expected range is [0, 1].</param>
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/// <param name="gamma">The gamma value to use for decoding.</param>
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/// <returns>The linear value.</returns>
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[Pure]
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[MethodImpl(CompilerResources.MethodImplOptions)]
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public static double GammaToLinear(double value, double gamma)
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{
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return System.Math.Pow(value, 1.0 / gamma);
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}
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/// <summary>
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/// Converts a linear value to a gamma-encoded value using a gamma value of <c>2.2</c>.
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/// </summary>
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@ -288,64 +377,6 @@ public static class MathUtility
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#endif
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}
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/// <summary>
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/// Returns the incremental sawtooth wave of a given value.
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/// </summary>
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/// <param name="value">The value to calculate.</param>
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/// <returns>The sawtooth wave of the given value.</returns>
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public static float Sawtooth(float value)
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{
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return (value - MathF.Floor(value));
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}
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/// <summary>
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/// Returns the incremental sawtooth wave of a given value.
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/// </summary>
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/// <param name="value">The value to calculate.</param>
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/// <returns>The sawtooth wave of the given value.</returns>
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public static double Sawtooth(double value)
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{
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return (value - System.Math.Floor(value));
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}
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/// <summary>
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/// Converts a value from being a percentage of one range, to being the same percentage in a new range.
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/// </summary>
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/// <param name="value">The value to convert.</param>
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/// <param name="oldMin">The old minimum value.</param>
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/// <param name="oldMax">The old maximum value.</param>
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/// <param name="newMin">The new minimum value.</param>
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/// <param name="newMax">The new maximum value.</param>
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/// <returns>The scaled value.</returns>
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[Pure]
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[MethodImpl(CompilerResources.MethodImplOptions)]
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public static float ScaleRange(float value, float oldMin, float oldMax, float newMin, float newMax)
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{
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float oldRange = oldMax - oldMin;
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float newRange = newMax - newMin;
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float alpha = (value - oldMin) / oldRange;
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return (alpha * newRange) + newMin;
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}
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/// <summary>
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/// Converts a value from being a percentage of one range, to being the same percentage in a new range.
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/// </summary>
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/// <param name="value">The value to convert.</param>
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/// <param name="oldMin">The old minimum value.</param>
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/// <param name="oldMax">The old maximum value.</param>
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/// <param name="newMin">The new minimum value.</param>
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/// <param name="newMax">The new maximum value.</param>
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/// <returns>The scaled value.</returns>
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[Pure]
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[MethodImpl(CompilerResources.MethodImplOptions)]
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public static double ScaleRange(double value, double oldMin, double oldMax, double newMin, double newMax)
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{
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double oldRange = oldMax - oldMin;
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double newRange = newMax - newMin;
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double alpha = (value - oldMin) / oldRange;
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return (alpha * newRange) + newMin;
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}
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/// <summary>
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/// Calculates the sigmoid function for the given input value.
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/// </summary>
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@ -374,18 +405,92 @@ public static class MathUtility
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return 1.0f / (1.0f + System.Math.Exp(-value));
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}
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#if NET7_0_OR_GREATER
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/// <summary>
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/// Performs smooth Hermite interpolation from one value to a target using a specified alpha.
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/// Applies a simple bias function to value.
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/// </summary>
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/// <param name="value">The value to which the bias function will be applied.</param>
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/// <param name="bias">The bias value. Valid values range from 0-1.</param>
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/// <returns>The biased result.</returns>
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/// <remarks>
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/// If <paramref name="bias" /> is less than 0.5, <paramref name="value" /> will be shifted downward; otherwise, upward.
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/// </remarks>
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public static TNumber Bias<TNumber>(TNumber value, TNumber bias)
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where TNumber : INumber<TNumber>
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{
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TNumber identity = TNumber.MultiplicativeIdentity;
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return value / ((identity / bias - TNumber.CreateChecked(2)) * (identity - value) + identity);
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}
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/// <summary>
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/// Returns the linear interpolation inverse of a value, such that it determines where a value lies between two other
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/// values.
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/// </summary>
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/// <param name="alpha">The value whose lerp inverse is to be found.</param>
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/// <param name="start">The start of the range.</param>
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/// <param name="end">The end of the range.</param>
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/// <returns>A value determined by <c>(alpha - start) / (end - start)</c>.</returns>
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[Pure]
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[MethodImpl(CompilerResources.MethodImplOptions)]
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public static TNumber InverseLerp<TNumber>(TNumber alpha, TNumber start, TNumber end)
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where TNumber : INumber<TNumber>
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{
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if (start == end)
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{
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return TNumber.Zero;
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}
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return (alpha - start) / (end - start);
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}
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/// <summary>
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/// Linearly interpolates from one value to a target using a specified alpha.
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/// </summary>
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/// <param name="value">The interpolation source.</param>
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/// <param name="target">The interpolation target.</param>
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/// <param name="alpha">The interpolation alpha.</param>
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/// <returns>The interpolation result.</returns>
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public static float SmoothStep(float value, float target, float alpha)
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/// <returns>
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/// The interpolation result as determined by <c>(1 - alpha) * value + alpha * target</c>.
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/// </returns>
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[Pure]
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[MethodImpl(CompilerResources.MethodImplOptions)]
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public static TNumber Lerp<TNumber>(TNumber value, TNumber target, TNumber alpha)
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where TNumber : INumber<TNumber>
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{
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alpha = System.Math.Clamp(alpha, 0.0f, 1.0f);
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alpha = -2.0f * alpha * alpha * alpha + 3.0f * alpha * alpha;
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return target * alpha + value * (1.0f - alpha);
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// rookie mistake: a + t * (b - a)
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// "precise" method: (1 - t) * a + t * b
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return ((TNumber.MultiplicativeIdentity - alpha) * value) + (alpha * target);
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}
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/// <summary>
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/// Returns the incremental sawtooth wave of a given value.
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/// </summary>
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/// <param name="value">The value to calculate.</param>
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/// <returns>The sawtooth wave of the given value.</returns>
|
||||
public static TNumber Sawtooth<TNumber>(TNumber value)
|
||||
where TNumber : IFloatingPoint<TNumber>
|
||||
{
|
||||
return (value - TNumber.Floor(value));
|
||||
}
|
||||
|
||||
/// <summary>
|
||||
/// Converts a value from being a percentage of one range, to being the same percentage in a new range.
|
||||
/// </summary>
|
||||
/// <param name="value">The value to convert.</param>
|
||||
/// <param name="oldMin">The old minimum value.</param>
|
||||
/// <param name="oldMax">The old maximum value.</param>
|
||||
/// <param name="newMin">The new minimum value.</param>
|
||||
/// <param name="newMax">The new maximum value.</param>
|
||||
/// <returns>The scaled value.</returns>
|
||||
[Pure]
|
||||
[MethodImpl(CompilerResources.MethodImplOptions)]
|
||||
public static TNumber ScaleRange<TNumber>(TNumber value, TNumber oldMin, TNumber oldMax, TNumber newMin, TNumber newMax)
|
||||
where TNumber : INumber<TNumber>
|
||||
{
|
||||
TNumber oldRange = oldMax - oldMin;
|
||||
TNumber newRange = newMax - newMin;
|
||||
TNumber alpha = (value - oldMin) / oldRange;
|
||||
return (alpha * newRange) + newMin;
|
||||
}
|
||||
|
||||
/// <summary>
|
||||
@ -395,10 +500,16 @@ public static class MathUtility
|
||||
/// <param name="target">The interpolation target.</param>
|
||||
/// <param name="alpha">The interpolation alpha.</param>
|
||||
/// <returns>The interpolation result.</returns>
|
||||
public static double SmoothStep(double value, double target, double alpha)
|
||||
public static TNumber SmoothStep<TNumber>(TNumber value, TNumber target, TNumber alpha)
|
||||
where TNumber : INumber<TNumber>
|
||||
{
|
||||
alpha = System.Math.Clamp(alpha, 0.0, 1.0);
|
||||
alpha = -2.0 * alpha * alpha * alpha + 3.0 * alpha * alpha;
|
||||
return target * alpha + value * (1.0 - alpha);
|
||||
TNumber one = TNumber.One;
|
||||
TNumber two = one + one;
|
||||
TNumber three = two + one;
|
||||
|
||||
alpha = TNumber.Clamp(alpha, TNumber.Zero, TNumber.One);
|
||||
alpha = -two * alpha * alpha * alpha + three * alpha * alpha;
|
||||
return target * alpha + value * (one - alpha);
|
||||
}
|
||||
#endif
|
||||
}
|
||||
|
||||
104
X10D/src/Math/NumberExtensions.cs
Normal file
104
X10D/src/Math/NumberExtensions.cs
Normal file
@ -0,0 +1,104 @@
|
||||
#if NET7_0_OR_GREATER
|
||||
using System.Diagnostics.Contracts;
|
||||
using System.Numerics;
|
||||
using System.Runtime.CompilerServices;
|
||||
using X10D.CompilerServices;
|
||||
|
||||
namespace X10D.Math;
|
||||
|
||||
/// <summary>
|
||||
/// Math-related extension methods for <see cref="INumber{TSelf}" />.
|
||||
/// </summary>
|
||||
public static class NumberExtensions
|
||||
{
|
||||
/// <summary>
|
||||
/// Returns a value indicating whether the current value is evenly divisible by 2.
|
||||
/// </summary>
|
||||
/// <param name="value">The value whose parity to check.</param>
|
||||
/// <returns>
|
||||
/// <see langword="true" /> if <paramref name="value" /> is evenly divisible by 2, or <see langword="false" />
|
||||
/// otherwise.
|
||||
/// </returns>
|
||||
[Pure]
|
||||
[MethodImpl(CompilerResources.MethodImplOptions)]
|
||||
public static bool IsEven<TNumber>(this TNumber value)
|
||||
where TNumber : INumber<TNumber>
|
||||
{
|
||||
return value % TNumber.CreateChecked(2) == TNumber.Zero;
|
||||
}
|
||||
|
||||
/// <summary>
|
||||
/// Returns a value indicating whether the current value is not evenly divisible by 2.
|
||||
/// </summary>
|
||||
/// <param name="value">The value whose parity to check.</param>
|
||||
/// <returns>
|
||||
/// <see langword="true" /> if <paramref name="value" /> is not evenly divisible by 2, or <see langword="false" />
|
||||
/// otherwise.
|
||||
/// </returns>
|
||||
[Pure]
|
||||
[MethodImpl(CompilerResources.MethodImplOptions)]
|
||||
public static bool IsOdd<TNumber>(this TNumber value)
|
||||
where TNumber : INumber<TNumber>
|
||||
{
|
||||
return !value.IsEven();
|
||||
}
|
||||
|
||||
/// <summary>
|
||||
/// Performs a modulo operation which supports a negative dividend.
|
||||
/// </summary>
|
||||
/// <param name="dividend">The dividend.</param>
|
||||
/// <param name="divisor">The divisor.</param>
|
||||
/// <returns>The result of <c>dividend mod divisor</c>.</returns>
|
||||
/// <remarks>
|
||||
/// The <c>%</c> operator (commonly called the modulo operator) in C# is not defined to be modulo, but is instead
|
||||
/// remainder. This quirk inherently makes it difficult to use modulo in a negative context, as <c>x % y</c> where x is
|
||||
/// negative will return a negative value, akin to <c>-(x % y)</c>, even if precedence is forced. This method provides a
|
||||
/// modulo operation which supports negative dividends.
|
||||
/// </remarks>
|
||||
/// <author>ShreevatsaR, https://stackoverflow.com/a/1082938/1467293</author>
|
||||
/// <license>CC-BY-SA 2.5</license>
|
||||
[Pure]
|
||||
[MethodImpl(CompilerResources.MethodImplOptions)]
|
||||
public static TNumber Mod<TNumber>(this TNumber dividend, TNumber divisor)
|
||||
where TNumber : INumber<TNumber>
|
||||
{
|
||||
TNumber r = dividend % divisor;
|
||||
return r < TNumber.Zero ? r + divisor : r;
|
||||
}
|
||||
|
||||
/// <summary>
|
||||
/// Returns an integer that indicates the sign of this number.
|
||||
/// </summary>
|
||||
/// <param name="value">A signed number.</param>
|
||||
/// <returns>
|
||||
/// A number that indicates the sign of <paramref name="value" />, as shown in the following table.
|
||||
///
|
||||
/// <list type="table">
|
||||
/// <listheader>
|
||||
/// <term>Return value</term>
|
||||
/// <description>Meaning</description>
|
||||
/// </listheader>
|
||||
///
|
||||
/// <item>
|
||||
/// <term>-1</term>
|
||||
/// <description><paramref name="value" /> is less than zero.</description>
|
||||
/// </item>
|
||||
/// <item>
|
||||
/// <term>0</term>
|
||||
/// <description><paramref name="value" /> is equal to zero.</description>
|
||||
/// </item>
|
||||
/// <item>
|
||||
/// <term>1</term>
|
||||
/// <description><paramref name="value" /> is greater than zero.</description>
|
||||
/// </item>
|
||||
/// </list>
|
||||
/// </returns>
|
||||
[Pure]
|
||||
[MethodImpl(CompilerResources.MethodImplOptions)]
|
||||
public static int Sign<TNumber>(this TNumber value)
|
||||
where TNumber : INumber<TNumber>
|
||||
{
|
||||
return TNumber.Sign(value);
|
||||
}
|
||||
}
|
||||
#endif
|
||||
Loading…
Reference in New Issue
Block a user