From a4032d069ee1032e2587ee051a353ade23d960b8 Mon Sep 17 00:00:00 2001
From: Chris Forbes <chrisf@ijw.co.nz>
Date: Mon, 8 Mar 2010 23:43:53 +1300
Subject: [PATCH] borrowed Mono's RNG.

---
 OpenRA.FileFormats/OpenRA.FileFormats.csproj |   3 +-
 OpenRA.FileFormats/Thirdparty/Random.cs      | 139 +++++++++++++++++++
 OpenRA.Game/World.cs                         |   6 +-
 3 files changed, 145 insertions(+), 3 deletions(-)
 create mode 100644 OpenRA.FileFormats/Thirdparty/Random.cs

diff --git a/OpenRA.FileFormats/OpenRA.FileFormats.csproj b/OpenRA.FileFormats/OpenRA.FileFormats.csproj
index 1b66837ab3..174eb124e5 100644
--- a/OpenRA.FileFormats/OpenRA.FileFormats.csproj
+++ b/OpenRA.FileFormats/OpenRA.FileFormats.csproj
@@ -1,4 +1,4 @@
-<?xml version="1.0" encoding="utf-8"?>
+<?xml version="1.0" encoding="utf-8"?>
 <Project DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003" ToolsVersion="3.5">
   <PropertyGroup>
     <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
@@ -80,6 +80,7 @@
     <Compile Include="PriorityQueue.cs" />
     <Compile Include="Properties\AssemblyInfo.cs" />
     <Compile Include="ProtocolVersion.cs" />
+    <Compile Include="Thirdparty\Random.cs" />
     <Compile Include="Session.cs" />
     <Compile Include="ShpReader.cs" />
     <Compile Include="ShroudPaletteRemap.cs" />
diff --git a/OpenRA.FileFormats/Thirdparty/Random.cs b/OpenRA.FileFormats/Thirdparty/Random.cs
new file mode 100644
index 0000000000..2f6c9dd14b
--- /dev/null
+++ b/OpenRA.FileFormats/Thirdparty/Random.cs
@@ -0,0 +1,139 @@
+//
+// System.Random.cs
+//
+// Authors:
+//   Bob Smith (bob@thestuff.net)
+//   Ben Maurer (bmaurer@users.sourceforge.net)
+//
+// (C) 2001 Bob Smith.  http://www.thestuff.net
+// (C) 2003 Ben Maurer
+//
+
+//
+// Copyright (C) 2004 Novell, Inc (http://www.novell.com)
+//
+// Permission is hereby granted, free of charge, to any person obtaining
+// a copy of this software and associated documentation files (the
+// "Software"), to deal in the Software without restriction, including
+// without limitation the rights to use, copy, modify, merge, publish,
+// distribute, sublicense, and/or sell copies of the Software, and to
+// permit persons to whom the Software is furnished to do so, subject to
+// the following conditions:
+// 
+// The above copyright notice and this permission notice shall be
+// included in all copies or substantial portions of the Software.
+// 
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+//
+
+using System;
+namespace OpenRA.Thirdparty
+{
+	[Serializable]
+	public class Random
+	{
+		const int MBIG = int.MaxValue;
+		const int MSEED = 161803398;
+		const int MZ = 0;
+
+		int inext, inextp;
+		int [] SeedArray = new int [56];
+		
+		public Random ()
+			: this (Environment.TickCount)
+		{
+		}
+
+		public Random (int Seed)
+		{
+			int ii;
+			int mj, mk;
+
+			// Numerical Recipes in C online @ http://www.library.cornell.edu/nr/bookcpdf/c7-1.pdf
+			mj = MSEED - Math.Abs (Seed);
+			SeedArray [55] = mj;
+			mk = 1;
+			for (int i = 1; i < 55; i++) {  //  [1, 55] is special (Knuth)
+				ii = (21 * i) % 55;
+				SeedArray [ii] = mk;
+				mk = mj - mk;
+				if (mk < 0)
+					mk += MBIG;
+				mj = SeedArray [ii];
+			}
+			for (int k = 1; k < 5; k++) {
+				for (int i = 1; i < 56; i++) {
+					SeedArray [i] -= SeedArray [1 + (i + 30) % 55];
+					if (SeedArray [i] < 0)
+						SeedArray [i] += MBIG;
+				}
+			}
+			inext = 0;
+			inextp = 31;
+		}
+
+		protected virtual double Sample ()
+		{
+			int retVal;
+
+			if (++inext  >= 56) inext  = 1;
+			if (++inextp >= 56) inextp = 1;
+
+			retVal = SeedArray [inext] - SeedArray [inextp];
+
+			if (retVal < 0)
+				retVal += MBIG;
+
+			SeedArray [inext] = retVal;
+
+			return retVal * (1.0 / MBIG);
+		}
+
+		public virtual int Next ()
+		{
+			return (int)(Sample () * int.MaxValue);
+		}
+
+		public virtual int Next (int maxValue)
+		{
+			if (maxValue < 0)
+				throw new ArgumentOutOfRangeException("Max value is less then min value.");
+
+			return (int)(Sample () * maxValue);
+		}
+
+		public virtual int Next (int minValue, int maxValue)
+		{
+			if (minValue > maxValue)
+				throw new ArgumentOutOfRangeException("Min value is greater then max value.");
+
+			uint diff = (uint)(maxValue - minValue);
+			if (diff == 0)
+				return minValue;
+
+			int result = (int)(Sample () * diff + minValue);
+			return ((result != maxValue) ? result : (result - 1));
+		}
+
+		public virtual void NextBytes (byte [] buffer)
+		{
+			if (buffer == null)
+				throw new ArgumentNullException ("buffer");
+
+			for (int i = 0; i < buffer.Length; i++) {
+				buffer [i] = (byte)(Sample () * (byte.MaxValue + 1)); 
+			}
+		}
+
+		public virtual double NextDouble ()
+		{
+			return this.Sample ();
+		}
+	}
+}
diff --git a/OpenRA.Game/World.cs b/OpenRA.Game/World.cs
index 3adca8c670..a9711918b1 100644
--- a/OpenRA.Game/World.cs
+++ b/OpenRA.Game/World.cs
@@ -28,6 +28,8 @@ using OpenRA.Graphics;
 using OpenRA.Support;
 using OpenRA.Traits;
 
+using XRandom = OpenRA.Thirdparty.Random;
+
 namespace OpenRA
 {
 	public class World
@@ -36,8 +38,8 @@ namespace OpenRA
 		List<IEffect> effects = new List<IEffect>();
 		List<Action<World>> frameEndActions = new List<Action<World>>();
 
-		public Random SharedRandom = new Random(0);	// synced
-		public Random CosmeticRandom = new Random();	// not synced
+		public XRandom SharedRandom = new XRandom(0);	// synced
+		public XRandom CosmeticRandom = new XRandom();	// not synced
 
 		public readonly Dictionary<int, Player> players = new Dictionary<int, Player>();