Networking

I've started to look into the networking code for Dune. While I'm currently still in a phase of trying things out in a sandbox environment, I will work on the networking code from now on. Once that's in, I will add the other missing features in Dune.

I initially read a few articles on other (commercial) RTS games and how they did their networking. For instance, Age Of Empires used a Peer-to-peer setup to communicate with all the other players. The game was a perfect simulation on each client. They accomplished this by make the game 'turn-based'. The player input would be registered, packed up and send to all clients. Each action would be executed in a turn, and when the data was send out to all the other clients, it used current turn + 2. So, when the current turn was 1000, and the player wanted a villager to go and chop down a tree, the actual ordering would happen in turn 1002. Since turns only lasted 200ms each, the player wouldn't even notice the delay between clicking and seeing the action.

However, in such systems, it's problematic when lag is 500ms: A packet send with orders scheduled for turn 1002 would arrive during turn 1003. AOE would adopt to this by either halt the game(In severe cases), or stretch up the time needed for each turn. In the case of 500ms lag, it would increase the turn time to 250 or 275ms, giving each packet more time to arrive.

This seemed to work well(I tried AOE2 to test it out) and it ran like a charm. So, I wanted to implement a similar to that of AOE2. However, setting up a P2P network between clients is a pain in the ass. Esp. when you take NAT into consideration. The system would have to work like this:
- Each client connects to host
- On start game, the host opens a series of new ports, one for each client.
- Each client connects to this port and disconnects directly
For each client:
- The host sends all other clients to which other client they should connect by handing out the IP and port number.
- The clients connect to the other player since the NAT port is now opened up

- Host is done when all players are connected to eachother.

It's quite complex, and I'm not sure if it would even work. Perhaps I should give it another shot and try to set it up. Once it works, it should work like a charm.