This video covers networking in the Godot game engine. First, we start off creating a simple UDP socket server and a client. We then illustrate the use of HTTPClient to make a REST web service request. We then create a simple ENet based client and server in Godot. Finally, we create a simple lobby and networked game using GDScript keywords master, slave, sync, and remote.
The Video
Code Samples
SimpleClient.gd
extends SceneTree
func _init():
var socket = PacketPeerUDP.new()
socket.set_dest_address("127.0.0.1",4242)
socket.put_packet("quit".to_ascii())
print("Exiting application")
self.quit()
SimpleServer.gd
extends SceneTree
func _init():
var done = false
var socket = PacketPeerUDP.new()
if(socket.listen(4242,"127.0.0.1") != OK):
print("An error occurred listening on port 4242")
done = true;
else:
print("Listening on port 4242 on localhost")
while(done != true):
if(socket.get_available_packet_count() > 0):
var data = socket.get_packet().get_string_from_ascii()
if(data == "quit"):
done = true
else:
print("Data received: " + data)
socket.close()
print("Exiting application")
self.quit()
HTTPRequest.gd
extends Button
func _ready():
$HTTPRequest.connect("request_completed",self,"_on_HTTPRequest_request_completed")
func _on_Button_pressed():
$HTTPRequest.request("https://jsonplaceholder.typicode.com/todos/1",PoolStringArray([]),false)
func _on_HTTPRequest_request_completed( result, response_code, headers, body ):
if(response_code == 200):
get_parent().get_node("Label").text = body.get_string_from_utf8()
Client.gd
extends Node2D
func _ready():
var network = NetworkedMultiplayerENet.new()
network.create_client("127.0.0.1", 4242)
get_tree().set_network_peer(network)
network.connect("connection_failed",self,"_on_connection_failed")
get_tree().multiplayer.connect("network_peer_packet",self,"_on_packet_received")
func _on_connection_failed(error):
$labelStatus.text = "Error connecting to server " + error
func _on_packet_received(id,packet):
$labelServerData.text = packet.get_string_from_ascii()
func _on_buttonConnect_pressed():
var network = NetworkedMultiplayerENet.new()
network.create_client("127.0.0.1", 4242)
get_tree().set_network_peer(network)
func _on_buttonDisconnect_pressed():
get_tree().set_network_peer(null)
Server.gd
extends Label
func _ready():
var network = NetworkedMultiplayerENet.new()
network.create_server(4242, 2)
get_tree().set_network_peer(network)
network.connect("peer_connected",self,"_peer_connected")
network.connect("peer_disconnected",self,"_peer_disconnected")
func _peer_connected(id):
text = text + "\nUser " + str(id) + " connected"
get_parent().get_node("labelUserCount").text = "Total Users:" + str(get_tree().get_network_connected_peers().size())
func _peer_disconnected(id):
text = text + "\nUser " + str(id) + " disconnected"
get_parent().get_node("labelUserCount").text = "Total Users:" + str(get_tree().get_network_connected_peers().size())
extends Button
func _on_buttonSendData_pressed():
print("Sending data to client")
var textToSend = get_parent().get_node("textToSend").text
get_tree().multiplayer.send_bytes(textToSend.to_ascii())
Lobby.gd
extends Node2D
func _ready():
get_tree().connect("network_peer_connected", self, "_player_connected")
func _player_connected(id):
print("Player connected to server!")
#Game on!
globals.otherPlayerId = id
var game = preload("res://Game.tscn").instance()
get_tree().get_root().add_child(game)
hide()
func _on_buttonHost_pressed():
print("Hosting network")
var host = NetworkedMultiplayerENet.new()
var res = host.create_server(4242,2)
if res != OK:
print("Error creating server")
return
$buttonJoin.hide()
$buttonHost.disabled = true
get_tree().set_network_peer(host)
func _on_buttonJoin_pressed():
print("Joining network")
var host = NetworkedMultiplayerENet.new()
host.create_client("127.0.0.1",4242)
get_tree().set_network_peer(host)
$buttonHost.hide()
$buttonJoin.disabled = true
Game.gd
extends Node2D
func _ready():
#First create ourself
var thisPlayer = preload("res://Player.tscn").instance()
thisPlayer.set_name(str(get_tree().get_network_unique_id()))
thisPlayer.set_network_master(get_tree().get_network_unique_id())
add_child(thisPlayer)
#Now create the other player
var otherPlayer = preload("res://Player.tscn").instance()
otherPlayer.set_name(str(globals.otherPlayerId))
otherPlayer.set_network_master(globals.otherPlayerId)
add_child(otherPlayer)
Player.gd
extends Node2D
slave func setPosition(pos):
position = pos
master func shutItDown():
#Send a shutdown command to all connected clients, including this one
rpc("shutDown")
sync func shutDown():
get_tree().quit()
func _process(delta):
var moveByX = 0
var moveByY = 0
if(is_network_master()):
if Input.is_key_pressed(KEY_LEFT):
moveByX = -5
if Input.is_key_pressed(KEY_RIGHT):
moveByX = 5
if Input.is_key_pressed(KEY_UP):
moveByY = -5
if Input.is_key_pressed(KEY_DOWN):
moveByY = 5
if Input.is_key_pressed(KEY_Q):
shutItDown()
# Tell the other computer about our new position so it can update
rpc_unreliable("setPosition",Vector2(position.x - moveByX, position.y))
# Move our local player
translate(Vector2(moveByX,moveByY))