P2P Networking
Steam has a mechanism allowing you to send packets to another Steam user.
It's totally feasible to create a game's netcode using this system.
In the past we used this in Rust to send voice communications instead of bouncing it off the server. We ultimately stopped doing this because it revealed your IP.
Sending Messages
byte[] mydata = ...
SteamId TargetSteamId = ...
var sent = SteamNetworking.SendP2PPacket( TargetSteamId, mydata );
// if sent is true - the data was sent !
Receiving Messages
You need to set up a callback so you can authorize who can send you messages
SteamNetworking.OnP2PSessionRequest = ( steamid ) =>
{
// If we want to let this steamid talk to us
SteamNetworking.AcceptP2PSessionWithUser( steamid );
}
Then just call something like this regularly
while ( SteamNetworking.IsP2PPacketAvailable() )
{
var packet = SteamNetworking.ReadP2PPacket();
if ( packet.HasValue )
{
HandleMessageFrom( packet.Value.SteamId, packet.Value.Data );
}
}
Your HandleMessageFrom function should look like this
void HandleMessageFrom( SteamId steamid, Data data )
{
.. do stuff
}
Further Reading
There are less garbage creating versions of some of the functions here on the SteamNetworking class.
Although the p2p stuff is easy and will work out for a lot of situations, you should look at SteamNetworkingSockets if you're planning to make a game with client/server architecture with 10+ players sending updates multiple times a second.
Garry's Mod
Rust
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