Modding Fika

Currently not updated for 3.11

Fika Events

Fika has a lot of events that you can subscribe to, which makes it easier to run code at certain key moments of the raid. To subscribe to an event, use:

public static void SubscribeEvent<TEvent>(Action<TEvent> callback) where TEvent : FikaEvent

To unsubscribe, use:

public static void UnsubscribeEvent<TEvent>(Action<TEvent> callback) where TEvent : FikaEvent

The event triggered will usually pass an important object related to the event, e.g. FikaNetworkManagerCreatedEvent passes a IFikaNetworkManager (named Manager in the object). This object can then be accessed if needed.

You can read the source code here to find all events.

Registering Packets

To register packets, subscribe to the FikaNetworkManagerCreatedEvent and access the IFikaNetworkManager. In the manager you can call either of these methods:

public void RegisterPacket<T>(Action<T> handle) where T : INetSerializable, new();

public void RegisterPacket<T, TUserData>(Action<T, TUserData> handle) where T : INetSerializable, new();

The INetSerializable needs to be a packet that you have created, and these methods are invoked when that packet is received. The second method also passes the NetPeer, which can be used to filter "packet bouncing" when received on the FikaServer. You handle the logic you want when receiving the packet in these methods.

Failing to register a packet will result in endless exceptions being thrown. Please register your packets correctly!

Creating a Packet

To create a packet, implement the INetSerializable interface into a new class. For packets that are sent often, I highly recommend using a struct. Add the data that you need in the form of Field and make all of them public. Then use the Serialize() and Deserialize() to write/read data. You can find an example here, which also includes how to write an enum. There are also a lot of extensions to write EFT/Unity specific data (e.g. Vector3) that you can find here.

Sending a Packet

To send a packet, you need a IFikaNetworkManager. This is either a FikaServer or FikaClient that you can access with the Comfort.Common using e.g. Singleton<FikaServer>.Instance. To determine whether you are a server or client, use FikaBackendUtils.IsServer.

Server

Use either of these methods:

public void SendDataToPeer<T>(NetPeer peer, ref T packet, DeliveryMethod deliveryMethod) where T : INetSerializable

public void SendDataToAll<T>(ref T packet, DeliveryMethod deliveryMethod, NetPeer peerToExclude = null) where T : INetSerializable

SendDataToPeer can be used to send a packet to just one NetPeer (which is useful for a response callback). SendDataToAll sends data to all clients, you can use the peerToExclude to exclude one NetPeer, which is useful if you don't want to "bounce" a packet back to the sender, but relay it to other clients. An example of this can be found here. In this scenario, we receive a player state and send it to everyone else, except for the one sending it as they are not interested in their own state.

Client

Use this method:

public void SendData<T>(ref T packet, DeliveryMethod deliveryMethod) where T : INetSerializable

It sends data to the server.

A client only has one NetPeer and it is the server! A client is never aware of other clients.

Tips and useful classes

• FikaBackendUtils has tons of useful methods/properties/fields that can be used.
• FikaGlobals has some helper methods that can be useful during development.
• CoopHandler has useful properties and methods, mainly to track players (especially human). It can be accessed on the Singleton<IFikaNetworkManager>.Instance or CoopHandler.TryGetCoopHandler() depending on your code style preference.