ScriptCore: Implemented Pick-Method and ThreadSafeRandom

ScriptCore/Math/Random.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Collections.Generic;
 
 namespace GlitchyEngine.Math;
 
@@ -31,4 +32,13 @@ public static class RandomExtension
     /// <returns>A 32-bit signed integer greater than or equal to <paramref name="min"/> and less than <paramref name="max"/>; that is, the range of return values includes <paramref name="min"/> but not <paramref name="max"/>. If <paramref name="min"/> equals <paramref name="max"/>, <paramref name="min"/> is returned.</returns>
     /// <exception cref="T:System.ArgumentOutOfRangeException"><paramref name="min"/> is greater than <paramref name="max"/>.</exception>
     public static double Range(this Random random, double min, double max) => random.NextDouble() * (max - min) + min;
+    
+    /// <summary>
+    /// Picks a random element from the given list.
+    /// </summary>
+    /// <param name="random"></param>
+    /// <param name="list">The list to pick an element from.</param>
+    /// <typeparam name="T">The type of elements in the list.</typeparam>
+    /// <returns>The randomly picked element.</returns>
+    public static T Pick<T>(this Random random, IList<T> list) => list[random.Range(0, list.Count)];
 }

ScriptCore/Math/ThreadSafeRandom.cs

@@ -0,0 +1,38 @@
+using System;
+
+namespace GlitchyEngine.Math;
+
+/// <summary>
+/// A thread safe global random number generator.
+/// </summary>
+/// <remarks>
+/// Based on https://andrewlock.net/building-a-thread-safe-random-implementation-for-dotnet-framework/
+/// </remarks>
+public static class ThreadSafeRandom
+{
+    [ThreadStatic]
+    private static Random? _local;
+    private static readonly Random Global = new();
+
+    /// <summary>
+    /// Gets a thread safe random number generator.
+    /// </summary>
+    public static Random Instance
+    {
+        get
+        {
+            if (_local is null)
+            {
+                int seed;
+                lock (Global)
+                {
+                    seed = Global.Next();
+                }
+
+                _local = new Random(seed);
+            }
+
+            return _local;
+        }
+    }
+}