Add random number generator

00_Common/dotnet/Games.Common/Randomness/RandomNumberGenerator.cs

@@ -0,0 +1,50 @@
+using System;
+
+namespace Games.Common.Randomness;
+
+public class RandomNumberGenerator : IRandom
+{
+    private Random _random;
+    private float _previous;
+
+    public RandomNumberGenerator()
+    {
+        // The BASIC RNG is seeded based on time with a 1 second resolution
+        _random = new Random((int)(DateTime.UtcNow.Ticks / TimeSpan.TicksPerSecond));
+    }
+
+    public float NextFloat() => NextFloat(1);
+
+    public float NextFloat(float exclusiveMaximum)
+    {
+        if (exclusiveMaximum <= 0)
+        {
+            throw new ArgumentOutOfRangeException(nameof(exclusiveMaximum), "Must be greater than 0.");
+        }
+
+        return NextFloat(0, exclusiveMaximum);
+    }
+
+    public float NextFloat(float inclusiveMinimum, float exclusiveMaximum)
+    {
+        if (exclusiveMaximum <= inclusiveMinimum)
+        {
+            throw new ArgumentOutOfRangeException(nameof(exclusiveMaximum), "Must be greater than inclusiveMinimum.");
+        }
+
+        var range = exclusiveMaximum - inclusiveMinimum;
+        return _previous = ((float)_random.NextDouble()) * range + inclusiveMinimum;
+    }
+
+    public int Next(int exclusiveMaximum) => ToInt(NextFloat(exclusiveMaximum));
+
+    public int Next(int inclusiveMinimum, int exclusiveMaximum) => ToInt(NextFloat(inclusiveMinimum, exclusiveMaximum));
+
+    public float PreviousFloat() => _previous;
+
+    public int Previous() => ToInt(_previous);
+
+    private static int ToInt(float value) => (int)Math.Floor(value);
+
+    public void Reseed(int seed) => _random = new Random(seed);
+}