Add helper methods for System.Random (#3832)

This might be a maint thing but look, I just want seeded RNG and IRobustRandom doesn't have it so not sure what is easier considering IRobustRandom is also registered as a depdency but constructing it manually is weird aaaa

Robust.Shared/Random/IRobustRandom.cs

@@ -2,53 +2,76 @@ using System;
 using System.Collections.Generic;
 using Robust.Shared.Maths;
 
-namespace Robust.Shared.Random
+namespace Robust.Shared.Random;
+
+public interface IRobustRandom
 {
-    public interface IRobustRandom
+    /// <summary>
+    /// Get the underlying System.Random
+    /// </summary>
+    /// <returns></returns>
+    System.Random GetRandom();
+
+    float NextFloat();
+    public float NextFloat(float minValue, float maxValue)
+        => NextFloat() * (maxValue - minValue) + minValue;
+    public float NextFloat(float maxValue) => NextFloat() * maxValue;
+    int Next();
+    int Next(int minValue, int maxValue);
+    TimeSpan Next(TimeSpan minTime, TimeSpan maxTime);
+    TimeSpan Next(TimeSpan maxTime);
+    int Next(int maxValue);
+    double NextDouble();
+    double NextDouble(double minValue, double maxValue) => NextDouble() * (maxValue - minValue) + minValue;
+    void NextBytes(byte[] buffer);
+
+    public Angle NextAngle() => NextFloat() * MathHelper.Pi * 2;
+    public Angle NextAngle(Angle minValue, Angle maxValue) => NextFloat() * (maxValue - minValue) + minValue;
+    public Angle NextAngle(Angle maxValue) => NextFloat() * maxValue;
+
+    /// <summary>
+    ///     Random vector, created from a uniform distribution of magnitudes and angles.
+    /// </summary>
+    /// <remarks>
+    ///     In general, NextVector2(1) will tend to result in vectors with smaller magnitudes than
+    ///     NextVector2Box(1,1), even if you ignored any vectors with a magnitude larger than one.
+    /// </remarks>
+    public Vector2 NextVector2(float minMagnitude, float maxMagnitude) => NextAngle().RotateVec((NextFloat(minMagnitude, maxMagnitude), 0));
+    public Vector2 NextVector2(float maxMagnitude = 1) => NextVector2(0, maxMagnitude);
+
+    /// <summary>
+    ///     Random vector, created from a uniform distribution of x and y coordinates lying inside some box.
+    /// </summary>
+    public Vector2 NextVector2Box(float minX, float minY, float maxX, float maxY) => new Vector2(NextFloat(minX, maxX), NextFloat(minY, maxY));
+    public Vector2 NextVector2Box(float maxAbsX = 1, float maxAbsY = 1) => NextVector2Box(-maxAbsX, -maxAbsY, maxAbsX, maxAbsY);
+
+    void Shuffle<T>(IList<T> list)
     {
-        float NextFloat();
-        public float NextFloat(float minValue, float maxValue)
-            => NextFloat() * (maxValue - minValue) + minValue;
-        public float NextFloat(float maxValue) => NextFloat() * maxValue;
-        int Next();
-        int Next(int minValue, int maxValue);
-        TimeSpan Next(TimeSpan minTime, TimeSpan maxTime);
-        TimeSpan Next(TimeSpan maxTime);
-        int Next(int maxValue);
-        double NextDouble();
-        double NextDouble(double minValue, double maxValue) => NextDouble() * (maxValue - minValue) + minValue;
-        void NextBytes(byte[] buffer);
-
-        public Angle NextAngle() => NextFloat() * MathHelper.Pi * 2;
-        public Angle NextAngle(Angle minValue, Angle maxValue) => NextFloat() * (maxValue - minValue) + minValue;
-        public Angle NextAngle(Angle maxValue) => NextFloat() * maxValue;
-
-        /// <summary>
-        ///     Random vector, created from a uniform distribution of magnitudes and angles.
-        /// </summary>
-        /// <remarks>
-        ///     In general, NextVector2(1) will tend to result in vectors with smaller magnitudes than
-        ///     NextVector2Box(1,1), even if you ignored any vectors with a magnitude larger than one.
-        /// </remarks>
-        public Vector2 NextVector2(float minMagnitude, float maxMagnitude) => NextAngle().RotateVec((NextFloat(minMagnitude, maxMagnitude), 0));
-        public Vector2 NextVector2(float maxMagnitude = 1) => NextVector2(0, maxMagnitude);
-
-        /// <summary>
-        ///     Random vector, created from a uniform distribution of x and y coordinates lying inside some box.
-        /// </summary>
-        public Vector2 NextVector2Box(float minX, float minY, float maxX, float maxY) => new Vector2(NextFloat(minX, maxX), NextFloat(minY, maxY));
-        public Vector2 NextVector2Box(float maxAbsX = 1, float maxAbsY = 1) => NextVector2Box(-maxAbsX, -maxAbsY, maxAbsX, maxAbsY);
-
-        void Shuffle<T>(IList<T> list)
+        var n = list.Count;
+        while (n > 1)
         {
-            var n = list.Count;
-            while (n > 1) {
-                n -= 1;
-                var k = Next(n + 1);
-                var value = list[k];
-                list[k] = list[n];
-                list[n] = value;
-            }
+            n -= 1;
+            var k = Next(n + 1);
+            (list[k], list[n]) = (list[n], list[k]);
         }
     }
 }
+
+public static class RandomHelpers
+{
+    public static void Shuffle<T>(this System.Random random, IList<T> list)
+    {
+        var n = list.Count;
+        while (n > 1)
+        {
+            n -= 1;
+            var k = random.Next(n + 1);
+            (list[k], list[n]) = (list[n], list[k]);
+        }
+    }
+
+    public static bool Prob(this System.Random random, double chance)
+    {
+        return random.NextDouble() < chance;
+    }
+}

Robust.Shared/Random/RobustRandom.cs

@@ -7,6 +7,8 @@ namespace Robust.Shared.Random
     {
         private readonly System.Random _random = new();
 
+        public System.Random GetRandom() => _random;
+
         public float NextFloat()
         {
             return _random.NextFloat();