Networking (Week 50 + Week 51)

Where do I start?
Well I started with assignment 3 last week, which consists of making a 3D game using DirectX. I became so overwhelmed (and still am) by the task that I basically did nothing for two weeks! Sure I read about programming patterns and networking and I did dibble in some network programming.

So that’s why I have no blog post from last week. I didn’t do anything worth blogging about.  So a few days ago I finally started working on the assignment.

I have made some basic server network code and a packet managing system and I have also merged my code with the code from our teacher Tommi.

I started out with networking because that’s hard to add when the game is already done. So my basic plan is this layout:

So the client or player does something. That is made into a packet of data that is stored in a queue that the packet handler / manager take care of.  

Next step is that this is sent down to the lower network level that actual take care of the sending and receiving data using UDP. So the packet is sent to the server and put into a queue by the packet handler on the server side and then the server reads and handles the data and updates the game logic and creates a new packet and sends it back to the client or to all clients depending on the logic inside.

As you can see in the picture above the client has its on local game logic. This is so the player can still collide and move around in the world without feedback from the server. This so the player don’t have to wait for half a second if a packet is lost along the way.

When the server has handled everything and the packet is back to the client there will be a check if the client position/ state is different from the server’s calculations. If it is then the client will be corrected to the server data.

Each packet is made up of a packet header and the actual data from the client or the server depending on where it’s created. I haven’t created the client side of the network yet so the code is not tested but this is how a header looks like:

The reason I made a header is so I can keep track of who created the packet. What type of packet it is. When it was created and how big it is and if it’s an outgoing or incoming packet. I don’t know if all this is needed but it’s a start and I’m no experienced network programmer.

Here is a link to my code:

https://bitbucket.org/georgios_chatzoglakis/assignments/src

If you can't read it then just ask me here and I will allow you access.