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<?xml version="1.0" encoding="UTF-8" ?>
<class name="WebRTCPeerConnection" inherits="Reference" version="4.0">
<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 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 ([code]A[/code] from now on) creates an offer and send it to the other peer ([code]B[/code] from now on).
- [code]B[/code] receives the offer, generate and answer, and sends it to [code]A[/code]).
- [code]A[/code] and [code]B[/code] 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.
</description>
<tutorials>
</tutorials>
<methods>
<method name="add_ice_candidate">
<return type="int" enum="Error">
</return>
<argument index="0" name="media" type="String">
</argument>
<argument index="1" name="index" type="int">
</argument>
<argument index="2" name="name" type="String">
</argument>
<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">
</return>
<description>
Close the peer connection and all data channels associated with it. Note, you cannot reuse this object for a new connection unless you call [method initialize].
</description>
</method>
<method name="create_data_channel">
<return type="WebRTCDataChannel">
</return>
<argument index="0" name="label" type="String">
</argument>
<argument index="1" name="options" type="Dictionary" default="{
}">
</argument>
<description>
Returns a new [WebRTCDataChannel] (or [code]null[/code] on failure) with given [code]label[/code] and optionally configured via the [code]options[/code] 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 [code]options[/code] 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">
</return>
<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">
</return>
<description>
Returns the connection state. See [enum ConnectionState].
</description>
</method>
<method name="initialize">
<return type="int" enum="Error">
</return>
<argument index="0" name="configuration" type="Dictionary" default="{
}">
</argument>
<description>
Re-initialize this peer connection, closing any previously active connection, and going back to state [constant STATE_NEW]. A dictionary of [code]options[/code] can be passed to configure the peer connection.
Valid [code]options[/code] 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]
</description>
</method>
<method name="poll">
<return type="int" enum="Error">
</return>
<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_local_description">
<return type="int" enum="Error">
</return>
<argument index="0" name="type" type="String">
</argument>
<argument index="1" name="sdp" type="String">
</argument>
<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">
</return>
<argument index="0" name="type" type="String">
</argument>
<argument index="1" name="sdp" type="String">
</argument>
<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 [code]type[/code] is [code]offer[/code] the peer will emit [signal session_description_created] with the appropriate answer.
If [code]type[/code] is [code]answer[/code] the peer will start emitting [signal ice_candidate_created].
</description>
</method>
</methods>
<signals>
<signal name="data_channel_received">
<argument index="0" name="channel" type="Object">
</argument>
<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">
<argument index="0" name="media" type="String">
</argument>
<argument index="1" name="index" type="int">
</argument>
<argument index="2" name="name" type="String">
</argument>
<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">
<argument index="0" name="type" type="String">
</argument>
<argument index="1" name="sdp" type="String">
</argument>
<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>
</constants>
</class>
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