Add transactional RV decor synchronization

network/network_session.gd

@@ -28,6 +28,7 @@ const MAX_PENDING_MOVEMENT_INPUTS: int = 96
 const ANIMATION_REFRESH_INTERVAL: float = 1.0
 const MAX_MOVEMENT_INPUT_SEQUENCE: int = 2147483647
 const MAX_MOVEMENT_ONE_WAY_TRANSIT_SECONDS: float = 0.25
+const SPACE_TRANSITION_SNAPSHOT_GUARD_DISTANCE: float = 12.0
 
 const MOVEMENT_FLAG_JUMP: int = 1 << 0
 const MOVEMENT_FLAG_SPRINT: int = 1 << 1
@@ -124,6 +125,9 @@ var _pending_movement_inputs: Array[Dictionary] = []
 var _snapshot_accumulator: float = 0.0
 var _movement_snapshot_tick: int = 0
 var _last_local_snapshot_received_msec: int = 0
+var _local_space_transition_guard_active: bool = false
+var _local_space_transition_guard_position: Vector3 = Vector3.ZERO
+var _local_space_transition_minimum_ack: int = 0
 var _animation_refresh_accumulator: float = 0.0
 var _last_animation_state_by_peer: Dictionary[int, Dictionary] = {}
 var _pending_animation_state_by_peer: Dictionary[int, Dictionary] = {}
@@ -703,6 +707,40 @@ func peers_share_space(first_peer_id: int, second_peer_id: int) -> bool:
 	return get_peer_space(first_peer_id) == get_peer_space(second_peer_id)
 
 
+func apply_authoritative_space_transition(
+	peer_id: int,
+	target_transform: Transform3D,
+	acknowledged_input: int,
+) -> bool:
+	if not target_transform.origin.is_finite():
+		return false
+	var local_peer_id: int = get_local_peer_id()
+	var local_transition: bool = peer_id == local_peer_id
+	var avatar: Player = _spawn_service.get_avatar(peer_id)
+	# Remote home transitions can arrive before their player-spawn message. Keep
+	# the new space assignment so the later spawn inherits correct visibility;
+	# only a missing local avatar is a transition failure.
+	if avatar == null:
+		return not local_transition
+	avatar.apply_network_space_transition(target_transform, local_transition)
+	if (
+		local_transition
+		and state == State.JOINED_CLIENT
+	):
+		# Movement snapshots use another ENet channel and a pre-transition audit
+		# can therefore arrive after the reliable home transition. Clear local
+		# prediction and reject those old-world snapshots until the host publishes
+		# its first audit from the new space.
+		_pending_movement_inputs.clear()
+		_last_local_snapshot_received_msec = 0
+		_last_input_state_hash = 0
+		_idle_input_accumulator = IDLE_INPUT_INTERVAL
+		_local_space_transition_guard_active = true
+		_local_space_transition_guard_position = target_transform.origin
+		_local_space_transition_minimum_ack = maxi(acknowledged_input, 0)
+	return true
+
+
 func get_peer_rtt_ms(peer_id: int) -> int:
 	if peer_id == 1:
 		return 0
@@ -2569,6 +2607,8 @@ func receive_movement_snapshots(encoded_snapshots: Array) -> void:
 		if avatar == null:
 			continue
 		if peer_id == local_peer_id:
+			if _reject_stale_space_transition_snapshot(snapshot):
+				continue
 			_discard_acknowledged_movement_inputs(
 				int(snapshot.get("acknowledged_input", 0))
 			)
@@ -2586,6 +2626,33 @@ func receive_movement_snapshots(encoded_snapshots: Array) -> void:
 			)
 
 
+func _reject_stale_space_transition_snapshot(snapshot: Dictionary) -> bool:
+	if not _local_space_transition_guard_active:
+		return false
+	var position_values: Array = snapshot.get("position", [])
+	if position_values.size() != 3:
+		return true
+	var position := Vector3(
+		float(position_values[0]),
+		float(position_values[1]),
+		float(position_values[2]),
+	)
+	var acknowledged_input: int = int(
+		snapshot.get("acknowledged_input", 0)
+	)
+	if acknowledged_input < _local_space_transition_minimum_ack:
+		return true
+	if acknowledged_input > _local_space_transition_minimum_ack:
+		_local_space_transition_guard_active = false
+		return false
+	if position.distance_to(_local_space_transition_guard_position) > (
+		SPACE_TRANSITION_SNAPSHOT_GUARD_DISTANCE
+	):
+		return true
+	_local_space_transition_guard_active = false
+	return false
+
+
 func _discard_acknowledged_movement_inputs(acknowledged_sequence: int) -> void:
 	while (
 		not _pending_movement_inputs.is_empty()
@@ -2914,6 +2981,9 @@ func _teardown_peer() -> void:
 	_snapshot_accumulator = 0.0
 	_movement_snapshot_tick = 0
 	_last_local_snapshot_received_msec = 0
+	_local_space_transition_guard_active = false
+	_local_space_transition_guard_position = Vector3.ZERO
+	_local_space_transition_minimum_ack = 0
 	_animation_refresh_accumulator = 0.0
 	_last_animation_state_by_peer.clear()
 	_pending_animation_state_by_peer.clear()