feat: add MathUtility.Sawtooth (#60)

CHANGELOG.md

@@ -16,6 +16,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - X10D: Added `MathUtility.Bias(float, float)` and `MathUtility.Bias(double, double)`.
 - X10D: Added `MathUtility.ExponentialDecay(float, float, float)` and `MathUtility.ExponentialDecay(double, double, double)`.
 - X10D: Added `MathUtility.InverseLerp(float, float, float)` and `MathUtility.InverseLerp(double, double, double)`.
+- X10D: Added `MathUtility.Sawtooth(float)` and `MathUtility.Sawtooth(double)`.
 - X10D: Added `MathUtility.ScaleRange(float, float, float, float, float)`
   and `MathUtility.ScaleRange(double, double, double, double, double)`
 - X10D: Added `MathUtility.Sigmoid(float)` and `MathUtility.Sigmoid(double)`.

X10D.Tests/src/Math/MathUtilityTests.cs

@@ -163,6 +163,72 @@ public class MathUtilityTests
         Assert.AreEqual(1.0f, floatResult);
     }
 
+    [TestMethod]
+    public void Sawtooth_ShouldReturn0Point5_Given0Point5AsDouble()
+    {
+        const double value = 0.5;
+
+        const double expected = 0.5;
+        double actual = MathUtility.Sawtooth(value);
+
+        Assert.AreEqual(expected, actual, 1e-6);
+    }
+
+    [TestMethod]
+    public void Sawtooth_ShouldReturn0Point5_Given0Point5AsSingle()
+    {
+        const float value = 0.5f;
+
+        const float expected = 0.5f;
+        float actual = MathUtility.Sawtooth(value);
+
+        Assert.AreEqual(expected, actual, 1e-6f);
+    }
+
+    [TestMethod]
+    public void Sawtooth_ShouldReturn0Point5_Given1Point5AsDouble()
+    {
+        const double value = 1.5;
+
+        const double expected = 0.5;
+        double actual = MathUtility.Sawtooth(value);
+
+        Assert.AreEqual(expected, actual, 1e-6);
+    }
+
+    [TestMethod]
+    public void Sawtooth_ShouldReturn0Point5_Given1Point5AsSingle()
+    {
+        const float value = 1.5f;
+
+        const float expected = 0.5f;
+        float actual = MathUtility.Sawtooth(value);
+
+        Assert.AreEqual(expected, actual, 1e-6f);
+    }
+
+    [TestMethod]
+    public void Sawtooth_ShouldReturn0Point5_GivenNegative1Point5AsDouble()
+    {
+        const double value = -1.5;
+
+        const double expected = 0.5;
+        double actual = MathUtility.Sawtooth(value);
+
+        Assert.AreEqual(expected, actual, 1e-6);
+    }
+
+    [TestMethod]
+    public void Sawtooth_ShouldReturn0Point5_GivenNegative1Point5AsSingle()
+    {
+        const float value = -1.5f;
+
+        const float expected = 0.5f;
+        float actual = MathUtility.Sawtooth(value);
+
+        Assert.AreEqual(expected, actual, 1e-6f);
+    }
+
     [TestMethod]
     public void ScaleRangeDouble_ShouldScaleRange_GivenItsValues()
     {

X10D/src/Math/MathUtility.cs

@@ -287,6 +287,26 @@ public static class MathUtility
         return System.Math.Pow(value, 1.0 / gamma);
     }
 
+    /// <summary>
+    ///     Returns the incremental sawtooth wave of a given value.
+    /// </summary>
+    /// <param name="value">The value to calculate.</param>
+    /// <returns>The sawtooth wave of the given value.</returns>
+    public static float Sawtooth(float value)
+    {
+        return (value - MathF.Floor(value));
+    }
+
+    /// <summary>
+    ///     Returns the incremental sawtooth wave of a given value.
+    /// </summary>
+    /// <param name="value">The value to calculate.</param>
+    /// <returns>The sawtooth wave of the given value.</returns>
+    public static double Sawtooth(double value)
+    {
+        return (value - System.Math.Floor(value));
+    }
+
     /// <summary>
     ///     Converts a value from being a percentage of one range, to being the same percentage in a new range.
     /// </summary>