completely moved MP unit spawn (spawnpoint stuff, etc) into a trait; moved trait from Player to World.

OpenRA.Game/Traits/World/SpawnDefaultUnits.cs

@@ -0,0 +1,72 @@
+#region Copyright & License Information
+/*
+ * Copyright 2007,2009,2010 Chris Forbes, Robert Pepperell, Matthew Bowra-Dean, Paul Chote, Alli Witheford.
+ * This file is part of OpenRA.
+ * 
+ *  OpenRA is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ * 
+ *  OpenRA is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ * 
+ *  You should have received a copy of the GNU General Public License
+ *  along with OpenRA.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#endregion
+
+using System.Collections.Generic;
+using System;
+using System.Linq;
+using OpenRA.FileFormats;
+
+namespace OpenRA.Traits
+{
+	class SpawnDefaultUnitsInfo : StatelessTraitInfo<SpawnDefaultUnits> { }
+
+	class SpawnDefaultUnits : IGameStarted
+	{
+		public void GameStarted(World world)
+		{
+			var taken = Game.LobbyInfo.Clients.Where(c => c.SpawnPoint != 0)
+				.Select(c => world.Map.SpawnPoints.ElementAt(c.SpawnPoint - 1)).ToList();
+
+			var available = world.Map.SpawnPoints.Except(taken).ToList();
+
+			foreach (var client in Game.LobbyInfo.Clients)
+			{
+				SpawnUnitsForPlayer(world.players[client.Index],
+					(client.SpawnPoint == 0)
+					? ChooseSpawnPoint(world, available, taken)
+					: world.Map.SpawnPoints.ElementAt(client.SpawnPoint - 1));
+			}	
+		}
+
+		void SpawnUnitsForPlayer(Player p, int2 sp)
+		{
+			p.World.CreateActor("mcv", sp, p);
+		}
+
+		static int2 ChooseSpawnPoint(World world, List<int2> available, List<int2> taken)
+		{
+			if (available.Count == 0)
+				throw new InvalidOperationException("No free spawnpoint.");
+
+			var n = taken.Count == 0
+				? world.SharedRandom.Next(available.Count)
+				: available			// pick the most distant spawnpoint from everyone else
+					.Select((k, i) => Pair.New(k, i))
+					.OrderByDescending(a => taken.Sum(t => (t - a.First).LengthSquared))
+					.Select(a => a.Second)
+					.First();
+
+			var sp = available[n];
+			available.RemoveAt(n);
+			taken.Add(sp);
+			return sp;
+		}
+	}
+}