allow optional mixes again; fix openal so it can *tell* when it fails to allocate sources, rather than just copying 400 bytes of ununitialized garbage into our managed space

OpenRa.FileFormats/Session.cs

@@ -31,7 +31,7 @@ namespace OpenRa.FileFormats
 		{
 			public string Map = "scm12ea.ini";
 			public string[] Packages = {};	// filename:sha1 pairs.
-			public string[] Mods = { "cnc" };	// mod names
+			public string[] Mods = { "ra" };	// mod names
 			public int OrderLatency = 3;
 		}
 	}

OpenRa.Game/Game.cs

@@ -44,8 +44,13 @@ namespace OpenRa
 				FileSystem.MountTemporary(new Folder(dir));
 
 			foreach (var pkg in manifest.Packages)
-				FileSystem.MountTemporary(new Package(pkg));
-			Timer.Time("mount tempory packages: {0}");
+				if (pkg.StartsWith( "~"))		// this package is optional.
+					try { FileSystem.MountTemporary(new Package(pkg.Substring(1))); }
+					catch { }
+				else
+					FileSystem.MountTemporary(new Package(pkg));
+
+			Timer.Time("mount temporary packages: {0}");
 		}
 		
 		public static void ChangeMap(string mapName)

OpenRa.Game/Sound.cs

@@ -136,7 +136,7 @@ namespace OpenRa
 	{
 		float volume = 1f;
 		Dictionary<int, bool> sourcePool = new Dictionary<int, bool>();
-		const int POOL_SIZE = 100;
+		const int POOL_SIZE = 32;
 
 		public OpenAlSoundEngine()
 		{
@@ -145,16 +145,18 @@ namespace OpenRa
 			if (dev == IntPtr.Zero)
 				throw new InvalidOperationException("Can't create OpenAL device");
 			var ctx = OpenAlInterop.alcCreateContext(dev, IntPtr.Zero);
+			if (ctx == IntPtr.Zero)
+				throw new InvalidOperationException("Can't create OpenAL context");
 			OpenAlInterop.alcMakeContextCurrent(ctx);
 
-			int[] sources = new int[POOL_SIZE];
-			IntPtr pTemp = Marshal.AllocHGlobal(sizeof(int) * POOL_SIZE);
-			OpenAlInterop.alGenSources(POOL_SIZE, pTemp);
-			Marshal.Copy(pTemp, sources, 0, POOL_SIZE);
-			Marshal.FreeHGlobal(pTemp);
-
-			foreach (int source in sources)
+			for (var i = 0; i < POOL_SIZE; i++)
+			{
+				var source = 0;
+				OpenAlInterop.alGenSources(1, out source);
+				if (0 != OpenAlInterop.alGetError())
+					throw new InvalidOperationException("failed generating source {0}".F(i));
 				sourcePool.Add(source, false);
+			}
 		}
 
 		int GetSourceFromPool()

OpenRa.Game/Support/OpenAlInterop.cs

@@ -51,8 +51,14 @@ namespace OpenRa.Support
 		[DllImport("OpenAL32.dll")]
 		public static extern void alBufferData(int buffer, int format, byte[] data, int size, int freq);
 
+		//[DllImport("OpenAL32.dll")]
+		//public static extern void alGenSources(int n, IntPtr sources);
+
 		[DllImport("OpenAL32.dll")]
-		public static extern void alGenSources(int n, IntPtr sources);
+		public static extern void alGenSources(int one, out int source);
+
+		[DllImport("OpenAL32.dll")]
+		public static extern int alGetError();
 
 		[DllImport("OpenAL32.dll")]
 		public static extern void alSourcef(int source, int param, float value);

mods/ra/mod.yaml

@@ -4,7 +4,7 @@ Folders:
 	./
 
 Packages:
-	main.mix
+	~main.mix
 	redalert.mix
 	conquer.mix
 	hires.mix