Files
VRyHungry1/Scenes/multiplayer_world.gd
T
algodoogle 61d92052ac Rebuild multiplayer on the stock spawner and synchronizer
Adding an object to the game no longer requires any networking code. The
MultiplayerSpawner runs in its default mode — no spawn_function, no payload
dictionary — and NetReplication builds each object's SceneReplicationConfig
from a convention, so scenes carry no hand-authored replication at all.

Every replicated node gets two generated synchronizers: NetSync for script
state, always server-owned, and NetXform for position, handed to whoever is
holding the object. That split is what makes grab prediction work — a
synchronizer never applies inbound state on the peer that owns it, so a
player's own hand drives an object with no round trip while is_dirty and
friends keep flowing one way from the server.

Interaction is now two RPCs for the whole game (NetGrab), and client gating is
one rule applied to every object (NetWorld). Deleted: net_pickable.gd, the
replicated net_held_by field and its held-state juggling, the
grant/reject/force-release negotiation, the static-item despawn RPC, and the
per-scene replication configs. Authority is the single source of truth for who
simulates an object.

Two things the convention had to learn, both found by the test suite:

  * Addon scripts are excluded. godot-xr-tools' snap zones and pickables expose
    a public `enabled`, which is exactly the flag each peer must set for itself
    — so replicating it meant the server sent `enabled = true` back over every
    client's gate, and stations went on grabbing objects out of the local
    player's hands.
  * Arrays of nodes are excluded. Array[Node3D] and Array[FoodItem] would
    otherwise try to serialise live node references.

table.gd's replicated state loses its underscore prefix, which now marks a
variable as private and unreplicated; two in-place array mutations there were
skipping their setters, and the progress bar could divide by zero on a client.

Suite: 146/146 passing.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
2026-07-28 22:04:22 +01:00

146 lines
5.5 KiB
GDScript

extends Node3D
## World script for the multiplayer scene. Starts the host/join the menu asked
## for, turns the authored kitchen into replicated objects, gives every connected
## peer an avatar, and returns to the menu when the session ends.
##
## The world's contents are NOT left baked into the scene file. Whatever the
## scene authors is treated as a template: the server spawns real copies of it
## through NetWorld and every peer drops its own authored originals. A client
## therefore shows the server's world rather than assuming its local copy of the
## scene matches — which is also exactly the path a player joining mid-session
## takes.
const PLAYER_SCENE := "res://Player/net_player.tscn"
## Whether to build the full kitchen on the machine that owns the world. The real
## game scene wants this; focused debug scenes bake their own handful of objects
## and turn it off, so the thing under test is not sharing the world with a
## second copy of the whole kitchen.
@export var populate_from_layout: bool = true
var xr_interface: XRInterface
var _net_world: NetWorld
var _populated := false
func _ready() -> void:
xr_interface = XRServer.find_interface("OpenXR")
if xr_interface and xr_interface.is_initialized():
DisplayServer.window_set_vsync_mode(DisplayServer.VSYNC_DISABLED)
get_viewport().use_xr = true
# Both roots go through the same generic replication hook, so a player avatar
# is just another replicated object — nothing about it is special-cased.
_net_world = NetWorld.new()
_net_world.name = "NetWorld"
add_child(_net_world)
_net_world.setup($ItemsSpawner, $WorldContent)
$PlayersSpawner.add_spawnable_scene(PLAYER_SCENE)
$Players.child_entered_tree.connect(_on_player_entered)
NetworkManager.register_world(self, _net_world)
NetworkManager.player_joined.connect(_on_player_joined)
NetworkManager.player_left.connect(_on_player_left)
NetworkManager.session_started.connect(_on_session_started)
NetworkManager.session_ended.connect(_on_session_ended)
NetworkManager.connection_failed.connect(_on_connection_failed)
# world_ready() is what actually calls host()/join() (or the command-line
# equivalent). Populating before this point would be wrong for every case, not
# just offline: is_online() is still false until host()/join() runs, so
# owns_world() reads true for a joining client too and it would build its own
# copy instead of receiving the server's. host() emits session_started
# synchronously, which populates via _on_session_started; the call after
# world_ready() only covers the case where neither ran — this scene opened
# directly, offline.
NetworkManager.world_ready()
_populate_world_if_owner()
func _on_player_entered(node: Node) -> void:
if node is MultiplayerSynchronizer:
return
NetReplication.attach(node)
func _exit_tree() -> void:
NetworkManager.unregister_world()
func _on_session_started(_is_server: bool) -> void:
_populate_world_if_owner()
## Turns the authored template into replicated objects, exactly once, on the
## machine that owns world logic. Safe to call from several entry points.
func _populate_world_if_owner() -> void:
if _populated or not populate_from_layout:
return
# WorldLayout reads the live scene tree to find what to replicate, so it has
# to be an instance sitting in that tree.
var layout := WorldLayout.new()
add_child(layout)
var authored := layout.get_authored_nodes()
# Every peer drops its authored copies. The client would otherwise show its
# local originals on top of the server's replicated ones, and the two sets
# would drift apart because only the server's are synced.
if not NetworkManager.owns_world():
NetworkManager.log_line("Clearing %d authored nodes; the server's copies replace them" % authored.size())
_remove_authored(authored)
layout.queue_free()
return
_populated = true
GameManager.meals_in_play = ["hamburger"]
var objects := layout.describe(authored)
layout.queue_free()
_remove_authored(authored)
NetworkManager.log_line("Populating world: %d objects" % objects.size())
for d in objects:
NetworkManager.spawn_item(d["scene"], d["xform"], d["name"], d["props"])
NetworkManager.log_line("World populated")
# Freed immediately rather than queue_free()d, so the names are released before
# the replicated copies are spawned under the same ones.
func _remove_authored(nodes: Array[Node]) -> void:
for node in nodes:
if is_instance_valid(node):
node.get_parent().remove_child(node)
node.free()
## Only the server (or the single offline machine) creates avatars;
## MultiplayerSpawner replicates the result to everyone else, late joiners
## included.
func _on_player_joined(peer_id: int) -> void:
if not NetworkManager.owns_world() or $Players.has_node(str(peer_id)):
return
var p: Node = load(PLAYER_SCENE).instantiate()
# The name is the peer id, which is how net_player.gd knows whose avatar it
# is on every peer — MultiplayerSpawner replicates the name.
p.name = str(peer_id)
$Players.add_child(p)
NetworkManager.log_line("Spawned avatar for peer %d" % peer_id)
func _on_player_left(peer_id: int) -> void:
if not NetworkManager.owns_world():
return
var p := $Players.get_node_or_null(str(peer_id))
if p:
p.queue_free()
NetworkManager.log_line("Despawned avatar for peer %d" % peer_id)
func _on_session_ended() -> void:
NetworkManager.log_line("Session ended, returning to main menu")
get_tree().change_scene_to_file("res://Scenes/mainMenu.tscn")
func _on_connection_failed() -> void:
NetworkManager.log_line("Connection failed, returning to main menu")
get_tree().change_scene_to_file("res://Scenes/mainMenu.tscn")