3. Server

Okay so we are done in obj_control. Let’s go to obj_server and obj_client. Both have the same structure. GMnet PUNCH uses the create event, the step event and the networking event of both. The following scripts can jsut be inserted as [the first] entries in these events. The GMnet PUNCH scripts will only run when needed and they won’t interupt your networking. If they do, please contact the support!

Server create event

obj_server’s create event get’s called on server creation (obviously). You need to create a player list (ds_list) there. This list will be used by GMnet PUNCH to store all players in. How to use them in your game will be explained later, but this is your only way to tell which player communicates with the server! You will also need a buffer that will be used for communication by the server. It should either be large or a growing buffer. The last thing you’ll need is a UDP server created by network_create_server(network_socket_udp,{port},{maxplayers}. All these will be fed into the udphp_createServer script.

_How to use udphpcreateServer (arguments):

  • server - A UDP server
  • buffer - A buffer
  • player-list - A ds_list that will store all players (more information below)

udphp_createServer will return either true or false. If the returned value is false, the server creation failed.

player_list = ds_list_create();
buffer = buffer_create(256, buffer_grow, 1);
server = network_create_server(network_socket_udp,1234,32);
ret = udphp_createServer(server,buffer,player_list);
if (!ret) {
    //Server could not be created. Destroy instace. GMnet PUNCH will also show a message if not silent.

Server step event

In obj_server’s step event the actual magic happens. Just run udphp_serverPunch with no arguments.

Server networking event

And in obj_server’s networking event we share the magic: Simply run udphp_serverNetworking with no arguemnts.

Server: Client identification

To identify clients in the networking event, you take the ip and the portof async_load and check if they are in the player list you created earlier. The player list stores keys in the format “ip:port”.

To see if a player is in the player list:

var in_ip = ds_map_find_value(async_load, "ip");
var in_port = ds_map_find_value(async_load, "port");
var exists = ds_list_find_index(player_list, in_ip+":"+string(in_port));
//exists will give you the position of the player in the list or -1 if he's not in there

To get ip and port of a player entry:

var entry = /* Entry from the player list */
var ip = udphp_playerListIP(entry);
var port = udphp_playerListPort(entry);

To send a message to all players iterate over the player list and send a packet to all players (see hello world demo in step event).

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