Interface to a WebRTC peer connection.
    public class WebRTCPeerConnection : Reference

A WebRTC connection between the local computer and a remote peer. Provides an interface to connect, maintain and monitor the connection.

Setting up a WebRTC connection between two peers from now on) may not seem a trivial task, but it can be broken down into 3 main steps:

  • The peer that wants to initiate the connection (A from now on) creates an offer and send it to the other peer (B from now on).

  • B receives the offer, generate and answer, and sends it to A).

  • A and B then generates and exchange ICE candidates with each other.

After these steps, the connection should become connected. Keep on reading or look into the tutorial for more information.

Inheritance Chain

Derived Classes

Constructors

    public WebRTCPeerConnection()

Signals

    "data_channel_received" (Object channel)

Emitted when a new in-band channel is received, i.e. when the channel was created with negotiated: false (default).

The object will be an instance of WebRTCDataChannel. You must keep a reference of it or it will be closed automatically. See CreateDataChannel(string, Godot.Collections.Dictionary)

    "ice_candidate_created" (String media, int index, String name)

Emitted when a new ICE candidate has been created. The three parameters are meant to be passed to the remote peer over the signaling server.

    "session_description_created" (String type, String sdp)

Emitted after a successful call to CreateOffer() or SetRemoteDescription(string, string) (when it generates an answer). The parameters are meant to be passed to SetLocalDescription(string, string) on this object, and sent to the remote peer over the signaling server.

Methods

    public Error AddIceCandidate(string media, int index, string name)

Add an ice candidate generated by a remote peer (and received over the signaling server). See ice_candidate_created.

    public void Close()

Close the peer connection and all data channels associated with it. Note, you cannot reuse this object for a new connection unless you call Initialize(Godot.Collections.Dictionary).

    public WebRTCDataChannel CreateDataChannel(string label, Dictionary options = null)

Returns a new WebRTCDataChannel (or null on failure) with given label and optionally configured via the options dictionary. This method can only be called when the connection is in state [constant STATE_NEW].

There are two ways to create a working data channel: either call CreateDataChannel(string, Godot.Collections.Dictionary) on only one of the peer and listen to data_channel_received on the other, or call CreateDataChannel(string, Godot.Collections.Dictionary) on both peers, with the same values, and the negotiated option set to true.

Valid options are:

[codeblock]

{

“negotiated”: true, # When set to true (default off), means the channel is negotiated out of band. “id” must be set too. data_channel_received will not be called.

“id”: 1, # When “negotiated” is true this value must also be set to the same value on both peer.

Only one of maxRetransmits and maxPacketLifeTime can be specified, not both. They make the channel unreliable (but also better at real time).

“maxRetransmits”: 1, # Specify the maximum number of attempt the peer will make to retransmits packets if they are not acknowledged.

“maxPacketLifeTime”: 100, # Specify the maximum amount of time before giving up retransmitions of unacknowledged packets (in milliseconds).

“ordered”: true, # When in unreliable mode (i.e. either “maxRetransmits” or “maxPacketLifetime” is set), “ordered” (true by default) specify if packet ordering is to be enforced.

“protocol”: “my-custom-protocol”, # A custom sub-protocol string for this channel.

}

[/codeblock]

Note: You must keep a reference to channels created this way, or it will be closed.

    public Error CreateOffer()

Creates a new SDP offer to start a WebRTC connection with a remote peer. At least one WebRTCDataChannel must have been created before calling this method.

If this functions returns [constant OK], session_description_created will be called when the session is ready to be sent.

    public ConnectionState GetConnectionState()

Returns the connection state. See ConnectionState.

    public Error Initialize(Dictionary configuration = null)

Re-initialize this peer connection, closing any previously active connection, and going back to state [constant STATE_NEW]. A dictionary of options can be passed to configure the peer connection.

Valid options are:

[codeblock]

{

“iceServers”: [

{

“urls”: [ “stun:stun.example.com:3478” ], # One or more STUN servers.

},

{

“urls”: [ “turn:turn.example.com:3478” ], # One or more TURN servers.

“username”: “a_username”, # Optional username for the TURN server.

“credentials”: “a_password”, # Optional password for the TURN server.

}

]

}

[/codeblock]

    public Error Poll()

Call this method frequently (e.g. in Node._Process(float) or Node._PhysicsProcess(float)) to properly receive signals.

    public Error SetLocalDescription(string type, string sdp)

Sets the SDP description of the local peer. This should be called in response to session_description_created.

If type is answer the peer will start emitting ice_candidate_created.

    public Error SetRemoteDescription(string type, string sdp)

Sets the SDP description of the remote peer. This should be called with the values generated by a remote peer and received over the signaling server.

If type is offer the peer will emit session_description_created with the appropriate answer.

If type is answer the peer will start emitting ice_candidate_created.

Inner Types

ConnectionState

Name Value Description
New 0 The connection is new, data channels and an offer can be created in this state.
Connecting 1 The peer is connecting, ICE is in progress, none of the transports has failed.
Connected 2 The peer is connected, all ICE transports are connected.
Disconnected 3 At least one ICE transport is disconnected.
Failed 4 One or more of the ICE transports failed.
Closed 5 The peer connection is closed (after calling [method close] for example).
Tags: