4. Client

4.1. Client create event

To create the udphp client with udphp_createClient you need a UDP socket (not server!), a buffer, as well as the server ip. The rest is explained in the argument listing: *How to use udphp_createClient (arguments)*:

• UDP client socket - A UDP socket
• Server IP(string) - The IP of the server to connect to (not the master server ip!)
• buffer - A buffer
• directconnect(bool) - If you set this to true, GMnet PUNCH will be bypassed. The client willdirectly connect to the server without hole punching. directconnect is automatically set to true when the master server is down or the server is not registered at the master server
• server_port(real) - This is optional. Set to 0 when unkown. This will be used (and is then required for successful connection) when the client connects directly and ONLY then. See above to know when it connects directly.

IMPORTANT: The function will return the client id you have to store. This id is used to identify this client. Using this you can run multiple clients in one game (as used in the demo). It will return -1 if the client could not be created.

buffer = buffer_create(256, buffer_grow, 1);
client = network_create_socket(network_socket_udp);

client_id = udphp_createClient(client,server_ip,buffer,false,1234);
if (client_id < 0) {
    //Client could not be created. Destroy instace. GMnet PUNCH will also show a message if not silent.
    instance_destroy();
}
`

4.2. Client step event

In the step event simply run udphp_clientPunch with the stored client id as argument. This function will return false if the client’s connection failed. This is the only way to determine if a connection process failed and it will return true in all other cases.

if (!udphp_clientPunch(client_id)) {
    //When this returns false, the connection failed or the client was destroyed.
    show_message("Connection failed!");
    instance_destroy();
}
`

4.3. Client networking event

In the networking event simply call udphp_clientNetworking with the client id as an argument.

4.4. Client: Get IP anf Port of server / check if connected

To communicate with the server after you are connected you of course need IP and port of the server, you also need to know if you are already connected. To do that use these functions:

var connected = udphp_clientIsConnected(client_id); //true or false
if (connected) {
   //The next functions will return invalid information if you use them without making sure you are connected:
   var ip = udphp_clientGetServerIP(client_id); //String
   var port = udphp_clientGetServerPort(client_id); //real
}

Please see the hello world demo scripts in obj_client for an example.

4.5. GMnet PUNCH is now set up!

In the next page we will show the last feature: The online lobby!