Props and player network management

Player management

Update properties

Client sends update to server

To update properties or actions from the client to the Godot server, you need to call the function client_send_action_to_server.

This is an example for a jump request:

client_send_action_to_server({"action": "jump"})

You can add more than one property in the argument.

Server receive update

The properties / actions received on the Godot server (can be sent by the client or by a Horizon service), these properties arrive in the function server_action_received. You need to manage the key => values.

For example, for the jump action received, we have:

func server_action_received(data: Dictionary) -> void:
match data["action"]:
"jump":
is_jumping = true

Server sends update to client

The server can send updated properties to the client, for example, the health.

To do that, call the function server_send_properties_to_client.

For example:

client_send_action_to_server({"health": 80})

Client receives update

The client receives all properties modified in the function client_channel_data_update, such as the new position and health.

For example:

func client_channel_data_update(data: Dictionary) -> void:
if data.has("health"):
health = data["health"]

Generic props management

What is a generic prop?

A generic prop is any scene spawned in the game, except for the player scene (normal_player.tscn).

It can be a planet, a box, a building, a car...

Structure of the gd file

For each generic prop scene, it MUST HAVE A GD SCRIPT ATTACHED.

This GD script must have at a minimum the following data inside (you can copy the content and paste it):

# TODO Change the class_name
class_name Box50cm

# TODO Update to the right node
extends RigidBody3D

signal hs_server_prop_update
signal hs_server_prop_delete

@export var uuid: String = ""

# TODO change the type
var type_name = "box"

var spawn_position: Vector3 = Vector3.ZERO
var spawn_rotation: Vector3 = Vector3.UP

var server_last_position = Vector3.ZERO
var server_last_rotation = Vector3.ZERO

var has_parent: bool = false

func _ready() -> void:
	position = spawn_position

func _physics_process(_delta: float) -> void:
	if GameOrchestrator.is_server():
    # this part send the position or rotation if changed since last frame
		var my_position = snapped(position, Vector3(0.001, 0.001, 0.001))
		var my_rotation = snapped(rotation, Vector3(0.0001, 0.0001, 0.0001))
		if server_last_position != my_position or server_last_rotation != my_rotation:
			emit_signal(
				"hs_server_prop_update",
				uuid,
				{
					"position": my_position,
					"rotation": my_rotation,
				},
				type_name,
				has_parent
			)
			server_last_position = my_position
			server_last_rotation = my_rotation

func _exit_tree() -> void:
	if GameOrchestrator.is_server():
    # send the information to the client the server delete this scene
		emit_signal(
			"hs_server_prop_delete",
			uuid,
			type_name
		)

# manage the parent changes
func client_parent_change(parent: Node) -> void:
	reparent(parent)
	has_parent = true

# receive the update from server, in this example, we manage position and rotation properties
func client_channel_data_update(data: Dictionary) -> void:
	if data.has("position"):
		position = Vector3(
			data["position"]["x"],
			data["position"]["y"],
			data["position"]["z"]
		)
	if data.has("rotation"):
		rotation = Vector3(
			data["rotation"]["x"],
			data["rotation"]["y"],
			data["rotation"]["z"]
		)

Update properties

Server sends update to client

The server can send updated properties to the client, for example, a LED state.

For that, you need to emit a signal on hs_server_prop_update with this code:

emit_signal(
"hs_server_prop_update",
uuid,
{
"led": true,
},
type_name,
has_parent
)

In the argument where we have led, we can put many properties. All other arguments are the same.

Client receives update

The client receives the properties updated by the server in the function client_channel_data_update.

The data argument is a dictionary where the key is the property and the value is the property value.

You can update or do what you want with the value.

value int

Be careful, the int value sent by the server is a float when it arrives, so you need to convert it to int before use.

Delete prop

To delete a prop, the function _exit_tree sends the signal to the client, and the client deletes the scene; it's automatic!