Initiating a Client/Server Session

Microsoft DirectX 8.1 (C++)

Initiating a Client/Server Session

A client/server game can be launched through a lobby, or directly by the server application.

The Server Application

Client/server games are often arranged through lobbies. The most straightforward way to launch the server is to implement it as a lobbyable application. This approach provides a way to launch the server, and supports communication between server and lobby during the course of the session. See DirectPlay Lobbies for further discussion.

A server can also be directly launched, and then advertise itself as available and wait for clients to connect. See Selecting a Client/Server Host for details.

Once the server application has been launched, it should initialize itself by calling IDirectPlay8Server::Initialize. As with other similar Microsoft® DirectPlay® methods, the primary purpose of initialization is to provide DirectPlay with a pointer to your callback message handler. You should also call IDirectPlay8Server::SetServerInfo to describe the current game. Clients cannot connect to a server until this method has been called.

The Client Application

One of the first steps you should take is to determine whether your game was lobby-launched. To do so, create and initialize a lobbied application object (CLSID_DirectPlay8LobbiedApplication). When you do so, you pass the object a pointer to your lobbied application message handler. This message handler receives messages directly from the lobbied application object, and indirectly from the lobby client and the lobby.

If the application was lobby-launched, the IDirectPlay8LobbiedApplication::Initialize method returns a connection handle for the lobby client and a DPL_MSGID_CONNECT message is sent to your lobbied application message handler. The pdplConnectionSettings member of the associated structure points to a DPL_CONNECTION_SETTINGSstructure that contains connection information such as an address object for the server.
If the application was not lobby launched, you will receive neither the connection handle, nor the message. However, if you call IDirectPlay8LobbiedApplication::SetAppAvailable, a lobby client can later connect your running application to a session by sending your lobbied application message handler a DPL_MSGID_CONNECT message.

You should also create and initialize a client object (CLSID_DirectPlay8Client). This object will be your primary means of communicating with Microsoft® DirectPlay® and the server. If you want to have multiple players in the session, you must create a separate instance of this object for each player.