Template Workshop 2: Lanlist Template

In this Workshop you will learn how you can search for game servers inside a lan. The templates for searching for servers inside a lan and over the internet are combined. Both have nearly the same interface and are easy to use. The internet template will be explained in detail in the next workshop.

Functions of the internet serverlist template start with ITemp_ and lan serverlist function start with LanTemp_.

The whole template is open source and can be easily adapted to your needs. If you find bugs or possible improvements, share them with us by sending me a mail or post a forum entry on the Gamestudio forum, please!

The theory behind

Beside the normal game server (which is started through enet_init_server()) a small server that listens on an other udp port is started. If players are searching for game servers, they will broadcast (that is sending to everybody) a "search" packet. Every game server that has this small udp server running will response with server related informations like the server name, number of players,... The player that sent the "search" packet will wait some time and collect all packets that are comming from the game servers. The server informations are then listed. After that, the whole list can be displayed on the screen and one of the servers can be selected to connect to.

Because the player should only find servers of the same game, the search packet contains a string that determines from which game the packet was sent. The first part of the string is the user_name the Gamestudio edition was registered to and the second part is userdefined. It's recommended to use the game's name here. So the whole string could look like this for example: "Peter SoxbergerCoolest ANet Game 2".

The time the servers need to response to the search packet is captured. The measured value is stored in the ping field (in ms) of the server list entry.

The example project

The template comes with an example project which is located in the "Example" folder. Start the application "LanTemp_Example.exe".

Press [A] to start a server. Now start the application again (don't close the current running one) and press [G]. After 3 seconds, the server should appear in a list. Now switch back to the server application and press [I] a few times. This increases the number of players. Switch back to the second application and press [G] again. The number of players should have changed now. If you have more than one computer at home and they are inside the same lan, you can start the server also on a different computer.
If you press [R], the server will be stopped and can't be found anymore.

Please notice that it's not possible to have a server running and doing a searching for servers in the same application!

How to include the template into a project?

First of all you have to copy the script files into your project main folder. The script files are located in the "Lite-C" folder.

Then add this line #include "Serverlist.h" after this line #include "anet.h".

Now you have full access to the template's functions.

A short overview

At first the template always has to be initialized by using this function:

The ServerListEntry struct:
This struct represents an entry in the server list. If you want to open a server that is added to the list, fill the struct with the informations about your server and share it through the function LanTemp_AddServer() (lan template) or ITemp_AddServer() (internet template).

The ServerList struct:
This struct represents the whole server list and is filled by LanTemp_GetList() or ITemp_GetList().

If you need an example code look into LanTemp_Example.c. For more informations about the template functions look into Serverlist.h.

Have fun!