fix: Use fixed seed for deterministic runs of the simulation

Author: twpol

Source/Contrib/SimulatorTester/Program.cs

@@ -70,7 +70,7 @@ static void Main(string[] args)
                 }
 
                 var startTime = DateTimeOffset.Now;
-                var simulator = new Simulator(settings, activityFile, false);
+                var simulator = new Simulator(settings, activityFile, useOpenRailsDirectory: false, deterministic: true);
                 simulator.SetActivity(activityFile);
                 simulator.Start(cts.Token);
                 simulator.SetCommandReceivers();

Source/Orts.Simulation/Simulation/Simulator.cs

@@ -253,10 +253,10 @@ public QueryCarViewerLoadedEventArgs(TrainCar car)
         public event System.EventHandler<QueryCarViewerLoadedEventArgs> QueryCarViewerLoaded;
         public event System.EventHandler RequestTTDetachWindow;
 
-        public Simulator(UserSettings settings, string activityPath, bool useOpenRailsDirectory)
+        public Simulator(UserSettings settings, string activityPath, bool useOpenRailsDirectory, bool deterministic = false)
         {
             Catalog = new GettextResourceManager("Orts.Simulation");
-            Random = new Random();
+            Random = deterministic ? new Random(0) : new Random();
 
             MPManager.Simulator = this;