From aa4aa9d158507b5c945409d28af5841161a0e640 Mon Sep 17 00:00:00 2001
From: Christoph Ruegg <git@cdrnet.ch>
Date: Thu, 18 Aug 2016 12:28:53 +0200
Subject: [PATCH] Random: explicit byte sampling implementation for
 MersenneTwister and XorShift

---
 src/Numerics/Random/MersenneTwister.cs | 11 +++++++++++
 src/Numerics/Random/Xorshift.cs        | 18 +++++++++++++++++-
 2 files changed, 28 insertions(+), 1 deletion(-)

diff --git a/src/Numerics/Random/MersenneTwister.cs b/src/Numerics/Random/MersenneTwister.cs
index bd8fed69..6cce7d08 100644
--- a/src/Numerics/Random/MersenneTwister.cs
+++ b/src/Numerics/Random/MersenneTwister.cs
@@ -341,6 +341,17 @@ namespace MathNet.Numerics.Random
             return int31;
         }
 
+        /// <summary>
+        /// Fills the elements of a specified array of bytes with random numbers in full range, including zero and 255 (<see cref="F:System.Byte.MaxValue"/>).
+        /// </summary>
+        protected sealed override void DoSampleBytes(byte[] buffer)
+        {
+            for (var i = 0; i < buffer.Length; i++)
+            {
+                buffer[i] = (byte)(genrand_int32() % 256);
+            }
+        }
+
         /* /// <summary>
         /// Generates a random number on [0,1) with 53-bit resolution.
         /// </summary>
diff --git a/src/Numerics/Random/Xorshift.cs b/src/Numerics/Random/Xorshift.cs
index 61f0e949..1c64226f 100644
--- a/src/Numerics/Random/Xorshift.cs
+++ b/src/Numerics/Random/Xorshift.cs
@@ -266,7 +266,7 @@ namespace MathNet.Numerics.Random
         /// <summary>
         /// Returns a random 32-bit signed integer greater than or equal to zero and less than <see cref="F:System.Int32.MaxValue"/>
         /// </summary>
-        protected override int DoSampleInteger()
+        protected sealed override int DoSampleInteger()
         {
             var t = (_a * _x) + _c;
             _x = _y;
@@ -283,6 +283,22 @@ namespace MathNet.Numerics.Random
             return int31;
         }
 
+        /// <summary>
+        /// Fills the elements of a specified array of bytes with random numbers in full range, including zero and 255 (<see cref="F:System.Byte.MaxValue"/>).
+        /// </summary>
+        protected sealed override void DoSampleBytes(byte[] buffer)
+        {
+            for (var i = 0; i < buffer.Length; i++)
+            {
+                var t = (_a * _x) + _c;
+                _x = _y;
+                _y = _z;
+                _c = t >> 32;
+                _z = t & 0xffffffff;
+                buffer[i] = (byte)(_z % 256);
+            }
+        }
+
         /// <summary>
         /// Fills an array with random numbers greater than or equal to 0.0 and less than 1.0.
         /// </summary>