Added original SDK code for Alien Swarm.

public/appframework/tier2app.h

@@ -0,0 +1,89 @@
+//=========== (C) Copyright 1999 Valve, L.L.C. All rights reserved. ===========
+//
+// The copyright to the contents herein is the property of Valve, L.L.C.
+// The contents may be used and/or copied only with the written permission of
+// Valve, L.L.C., or in accordance with the terms and conditions stipulated in
+// the agreement/contract under which the contents have been supplied.
+//
+// $Header: $
+// $NoKeywords: $
+//
+// The application object for apps that use tier2
+//=============================================================================
+
+#ifndef TIER2APP_H
+#define TIER2APP_H
+
+#ifdef _WIN32
+#pragma once
+#endif
+
+
+#include "appframework/AppFramework.h"
+#include "tier2/tier2dm.h"
+#include "tier1/convar.h"
+
+
+//-----------------------------------------------------------------------------
+// The application object for apps that use tier2
+//-----------------------------------------------------------------------------
+class CTier2SteamApp : public CSteamAppSystemGroup
+{
+	typedef CSteamAppSystemGroup BaseClass;
+
+public:
+	// Methods of IApplication
+	virtual bool PreInit()
+	{
+		CreateInterfaceFn factory = GetFactory();
+		ConnectTier1Libraries( &factory, 1 );
+		ConVar_Register( 0 );
+		ConnectTier2Libraries( &factory, 1 );
+		return true;			
+	}
+
+	virtual void PostShutdown()
+	{
+		DisconnectTier2Libraries();
+		ConVar_Unregister();
+		DisconnectTier1Libraries();
+	}
+
+	virtual void Destroy()
+	{
+	}
+};
+
+
+//-----------------------------------------------------------------------------
+// The application object for apps that use tier2 and datamodel
+//-----------------------------------------------------------------------------
+class CTier2DmSteamApp : public CTier2SteamApp
+{
+	typedef CTier2SteamApp BaseClass;
+
+public:
+	// Methods of IApplication
+	virtual bool PreInit()
+	{
+		if ( !BaseClass::PreInit() )
+			return false;
+
+		CreateInterfaceFn factory = GetFactory();
+		if ( !ConnectDataModel( factory ) )
+			return false;
+
+		InitReturnVal_t nRetVal = InitDataModel();
+		return ( nRetVal == INIT_OK );
+	}
+
+	virtual void PostShutdown()
+	{
+		ShutdownDataModel();
+		DisconnectDataModel();
+		BaseClass::PostShutdown();
+	}
+};
+
+
+#endif // TIER2APP_H