godot/modules/webrtc/doc_classes/WebRTCPeerConnection.xml

<?xml version="1.0" encoding="UTF-8" ?>
<class name="WebRTCPeerConnection" inherits="RefCounted" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="../../../doc/class.xsd">
	<brief_description>
		Interface to a WebRTC peer connection.
	</brief_description>
	<description>
		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 may not seem a trivial task, but it can be broken down into 3 main steps:
		- The peer that wants to initiate the connection ([code]A[/code] from now on) creates an offer and sends it to the other peer ([code]B[/code] from now on).
		- [code]B[/code] receives the offer, generates an answer, and sends it to [code]A[/code].
		- [code]A[/code] and [code]B[/code] then generate and exchange ICE candidates with each other.
		After these steps, the connection should be established. Refer to the linked tutorials for details.
	</description>
	<tutorials>
		<link title="WebRTC documentation">$DOCS_URL/tutorials/networking/webrtc.html</link>
		<link title="High-level multiplayer">$DOCS_URL/tutorials/networking/high_level_multiplayer.html</link>
	</tutorials>
	<methods>
		<method name="add_ice_candidate">
			<return type="int" enum="Error" />
			<param index="0" name="media" type="String" />
			<param index="1" name="index" type="int" />
			<param index="2" name="name" type="String" />
			<description>
				Add an ice candidate generated by a remote peer (and received over the signaling server). See [signal ice_candidate_created].
			</description>
		</method>
		<method name="close">
			<return type="void" />
			<description>
				Close the peer connection and all data channels associated with it.
				[b]Note:[/b] You cannot reuse this object for a new connection unless you call [method initialize].
			</description>
		</method>
		<method name="create_data_channel">
			<return type="WebRTCDataChannel" />
			<param index="0" name="label" type="String" />
			<param index="1" name="options" type="Dictionary" default="{}" />
			<description>
				Returns a new [WebRTCDataChannel] (or [code]null[/code] on failure) with given [param label] and optionally configured via the [param 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 [method create_data_channel] on only one of the peer and listen to [signal data_channel_received] on the other, or call [method create_data_channel] on both peers, with the same values, and the [code]"negotiated"[/code] option set to [code]true[/code].
				Valid [param 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]
				[b]Note:[/b] You must keep a reference to channels created this way, or it will be closed.
			</description>
		</method>
		<method name="create_offer">
			<return type="int" enum="Error" />
			<description>
				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], [signal session_description_created] will be called when the session is ready to be sent.
			</description>
		</method>
		<method name="get_connection_state" qualifiers="const">
			<return type="int" enum="WebRTCPeerConnection.ConnectionState" />
			<description>
				Returns the connection state.
			</description>
		</method>
		<method name="get_gathering_state" qualifiers="const">
			<return type="int" enum="WebRTCPeerConnection.GatheringState" />
			<description>
				Returns the ICE [enum GatheringState] of the connection. This lets you detect, for example, when collection of ICE candidates has finished.
			</description>
		</method>
		<method name="get_signaling_state" qualifiers="const">
			<return type="int" enum="WebRTCPeerConnection.SignalingState" />
			<description>
				Returns the signaling state on the local end of the connection while connecting or reconnecting to another peer.
			</description>
		</method>
		<method name="initialize">
			<return type="int" enum="Error" />
			<param index="0" name="configuration" type="Dictionary" default="{}" />
			<description>
				Re-initialize this peer connection, closing any previously active connection, and going back to state [constant STATE_NEW]. A dictionary of [param configuration] options can be passed to configure the peer connection.
				Valid [param configuration] 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.
							"credential": "a_password", # Optional password for the TURN server.
						}
					]
				}
				[/codeblock]
			</description>
		</method>
		<method name="poll">
			<return type="int" enum="Error" />
			<description>
				Call this method frequently (e.g. in [method Node._process] or [method Node._physics_process]) to properly receive signals.
			</description>
		</method>
		<method name="set_default_extension" qualifiers="static">
			<return type="void" />
			<param index="0" name="extension_class" type="StringName" />
			<description>
				Sets the [param extension_class] as the default [WebRTCPeerConnectionExtension] returned when creating a new [WebRTCPeerConnection].
			</description>
		</method>
		<method name="set_local_description">
			<return type="int" enum="Error" />
			<param index="0" name="type" type="String" />
			<param index="1" name="sdp" type="String" />
			<description>
				Sets the SDP description of the local peer. This should be called in response to [signal session_description_created].
				After calling this function the peer will start emitting [signal ice_candidate_created] (unless an [enum Error] different from [constant OK] is returned).
			</description>
		</method>
		<method name="set_remote_description">
			<return type="int" enum="Error" />
			<param index="0" name="type" type="String" />
			<param index="1" name="sdp" type="String" />
			<description>
				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 [param type] is [code]"offer"[/code] the peer will emit [signal session_description_created] with the appropriate answer.
				If [param type] is [code]"answer"[/code] the peer will start emitting [signal ice_candidate_created].
			</description>
		</method>
	</methods>
	<signals>
		<signal name="data_channel_received">
			<param index="0" name="channel" type="WebRTCDataChannel" />
			<description>
				Emitted when a new in-band channel is received, i.e. when the channel was created with [code]negotiated: false[/code] (default).
				The object will be an instance of [WebRTCDataChannel]. You must keep a reference of it or it will be closed automatically. See [method create_data_channel].
			</description>
		</signal>
		<signal name="ice_candidate_created">
			<param index="0" name="media" type="String" />
			<param index="1" name="index" type="int" />
			<param index="2" name="name" type="String" />
			<description>
				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.
			</description>
		</signal>
		<signal name="session_description_created">
			<param index="0" name="type" type="String" />
			<param index="1" name="sdp" type="String" />
			<description>
				Emitted after a successful call to [method create_offer] or [method set_remote_description] (when it generates an answer). The parameters are meant to be passed to [method set_local_description] on this object, and sent to the remote peer over the signaling server.
			</description>
		</signal>
	</signals>
	<constants>
		<constant name="STATE_NEW" value="0" enum="ConnectionState">
			The connection is new, data channels and an offer can be created in this state.
		</constant>
		<constant name="STATE_CONNECTING" value="1" enum="ConnectionState">
			The peer is connecting, ICE is in progress, none of the transports has failed.
		</constant>
		<constant name="STATE_CONNECTED" value="2" enum="ConnectionState">
			The peer is connected, all ICE transports are connected.
		</constant>
		<constant name="STATE_DISCONNECTED" value="3" enum="ConnectionState">
			At least one ICE transport is disconnected.
		</constant>
		<constant name="STATE_FAILED" value="4" enum="ConnectionState">
			One or more of the ICE transports failed.
		</constant>
		<constant name="STATE_CLOSED" value="5" enum="ConnectionState">
			The peer connection is closed (after calling [method close] for example).
		</constant>
		<constant name="GATHERING_STATE_NEW" value="0" enum="GatheringState">
			The peer connection was just created and hasn't done any networking yet.
		</constant>
		<constant name="GATHERING_STATE_GATHERING" value="1" enum="GatheringState">
			The ICE agent is in the process of gathering candidates for the connection.
		</constant>
		<constant name="GATHERING_STATE_COMPLETE" value="2" enum="GatheringState">
			The ICE agent has finished gathering candidates. If something happens that requires collecting new candidates, such as a new interface being added or the addition of a new ICE server, the state will revert to gathering to gather those candidates.
		</constant>
		<constant name="SIGNALING_STATE_STABLE" value="0" enum="SignalingState">
			There is no ongoing exchange of offer and answer underway. This may mean that the [WebRTCPeerConnection] is new ([constant STATE_NEW]) or that negotiation is complete and a connection has been established ([constant STATE_CONNECTED]).
		</constant>
		<constant name="SIGNALING_STATE_HAVE_LOCAL_OFFER" value="1" enum="SignalingState">
			The local peer has called [method set_local_description], passing in SDP representing an offer (usually created by calling [method create_offer]), and the offer has been applied successfully.
		</constant>
		<constant name="SIGNALING_STATE_HAVE_REMOTE_OFFER" value="2" enum="SignalingState">
			The remote peer has created an offer and used the signaling server to deliver it to the local peer, which has set the offer as the remote description by calling [method set_remote_description].
		</constant>
		<constant name="SIGNALING_STATE_HAVE_LOCAL_PRANSWER" value="3" enum="SignalingState">
			The offer sent by the remote peer has been applied and an answer has been created and applied by calling [method set_local_description]. This provisional answer describes the supported media formats and so forth, but may not have a complete set of ICE candidates included. Further candidates will be delivered separately later.
		</constant>
		<constant name="SIGNALING_STATE_HAVE_REMOTE_PRANSWER" value="4" enum="SignalingState">
			A provisional answer has been received and successfully applied in response to an offer previously sent and established by calling [method set_local_description].
		</constant>
		<constant name="SIGNALING_STATE_CLOSED" value="5" enum="SignalingState">
			The [WebRTCPeerConnection] has been closed.
		</constant>
	</constants>
</class>