M2.3: the shared world (trees, pickups, pieces, chests, fires, doors, graves, clock on the server)

docs/MULTIPLAYER_PLAN.md

@@ -18,10 +18,10 @@ concrete decisions for this codebase, as it stands after M1.
 
 ## 2. Running a server
 *Built in M2.1* (`scripts/net/net.gd`, `server_config.gd`, `identity.gd`).
-As of M2.1 the server accepts players, checks who they are and keeps the
+The server accepts players, checks who they are and keeps the player list.
-player list. The world itself isn't served yet (M2.3). Flags: `--server`,
+Since M2.3 it also runs the shared island (§5). Flags: `--server`,
 `--port`, `--config`, `--server-name`, `--max-players`, `--password`,
-`--world`, and `--exit-with <pid>` (quit when that process exits; the tests
+`--world`, `--seed`, and `--exit-with <pid>` (quit when that process exits; the tests
 use it so a crashed test never leaves a server running). Flags apply to
 that run only and are never written to `server.json`.
 ```bash
@@ -161,8 +161,9 @@ A refused move sends the player back to their last good position.
 Respawning is a flagged teleport, allowed if it lands within 25 m of the
 island spawn. Normal play is never corrected, so there's no rubber-banding.
 This is the Valheim model, and simpler than replaying inputs on the server.
-Through-wall checks come with the shared world (M2.3), since the server
+Since M2.3 the server also refuses a move whose straight line crosses a
-doesn't know about buildings yet.
+wall, door frame (or closed door) or gable at waist height, checked from
+both ends so someone a wall was built on top of can still step out.
 
 The server sends everyone's positions 20 times a second. Each one is stamped
 with when the player moved (their clock plus a smoothed per-player offset),
@@ -177,9 +178,38 @@ Measured in `tests/test_net_world.gd` at 100 ms ± 30 ms simulated latency:
 a 4 m/s walk is seen at a median of 4.2 m/s, top 5.0, with no freezes, and
 it ends within a centimetre of where the walker stopped.
 
-Until later phases, while online: animals are off (M2.5), and building,
+**The shared world** *(built in M2.3: `world_net.gd`, autoload WorldNet)*.
-gathering and other world changes are local only and aren't saved (M2.3,
+The dedicated server runs the real world scene headless with nobody of its
-M2.4). The HUD says so. Respawning ignores beds.
+own in it (`world.gd` `server_mode`), and saves it like a single-player
+world, in `worlds/<world>/` next to `server.json`. It owns trees and rocks
+(damage, felling, regrowth), pickups, berry bushes, dropped items, every
+placed piece (walls, doors, chests, graves, fires, beds), fire fuel, door
+state and the clock. Weather is worked out from the seed and the clock, so
+it needs no syncing.
+- A client's `Actions.*` intents that change the island become requests
+  (`_c2s_hit`, `_c2s_place`, `_c2s_take`, `_c2s_chest_click`...). The server
+  checks reach (from where it last saw that player), applies the change,
+  and tells everyone (`_s2c_node`, `_s2c_piece_added`...). Nothing changes
+  on your screen until the server says so, so two people grabbing the same
+  stick get one stick between them.
+- Whatever a change earns you (wood, a pickup, a dismantled wall and
+  anything that collapsed with it, items out of a chest) the server sends
+  to you (`_s2c_give`). What doesn't fit lands at your feet.
+- Pieces have a net id that's saved with them, so they keep it across
+  server restarts.
+- Chest clicks happen on the server (someone else may be using the chest),
+  which hands back what you're holding.
+- On joining, your world asks for a snapshot of everything once its
+  scenery is up, then gets each change in order. Regrowth only happens on
+  the server, never on top of a player.
+- The world (fires, regrowth, the clock) pauses while nobody's on.
+
+Until later phases, while online: your inventory, stats and crafting stay on
+your own game and aren't saved by the server (M2.4), so the server trusts
+what you say you're putting into the world (a wall, a chest deposit, a
+grave's contents) but decides everything taken out. Animals are off (M2.5).
+Sleeping is off (it needs the sleep rule, M2.5). Respawning ignores beds.
+The HUD says so.
 
 **Interest.** On a 320 m worldlet with 8 players, the server sends every
 entity to everyone at first. Distance-based interest is a later
@@ -208,6 +238,12 @@ worlds/<world>/
                            friends, name, appearance
   backups/<timestamp>/     rolling copies (backups_kept)
 ```
+*As of M2.3:* `worlds/<world>/meta.json` and `world.json` (with pieces'
+net ids, no owners yet) are written next to `server.json` within 10 s of
+any change, when a player leaves, and every `autosave_minutes`. (Ctrl+C
+kills Godot without running any code, so there's no save on the way out.) An
+existing world keeps the seed it was made with, even if `server.json`
+changes. Player files, owners and backups come in M2.4 and M2.7.
 - Single-player saves (today's `world.json` with a `"player"` block) are
   migrated on first load. That block becomes the local player's file. The
   test suite keeps an old-format save fixture to prove it.
@@ -237,7 +273,7 @@ player" or "this player":
 | **M2.0** | worldlet W0 (terrain from data, no visible change), recommended first | seed 1337 generates the same height grid as today; all suites pass |
 | **M2.1** *(done)* | network skeleton: `--server`, ENet on 24242, Join screen (address, name), handshake with identity and challenge, name rules, player list | two clients and a headless server on one Mac connect, see the player list, and disconnect cleanly |
 | **M2.2** *(done)* | player bodies and name tags; predicted movement, interpolation for others | two players walk around together at 100 ms simulated latency without visible rubber-banding |
-| **M2.3** | world state replicated: resource nodes, pickups, pieces, chests, fires, doors, clock, weather | one chops a tree and the other sees it fall; one builds a wall and the other walks into it |
+| **M2.3** *(done)* | world state replicated: resource nodes, pickups, pieces, chests, fires, doors, clock, weather | one chops a tree and the other sees it fall; one builds a wall and the other walks into it |
 | **M2.4** | intents as RPCs; per-player inventory, stats, diet, death and graves; per-player saves and migration | two players craft, eat, die and loot their own graves; an old single-player save loads |
 | **M2.5** | wildlife and wolves server-side, projectiles, fishing, sleeping with the rule | a pack hunts two players at once; arrows hit on both screens |
 | **M2.6** | server rules: PvP, raiding, locks and friends, death penalty, difficulty; admin console and chat | each preset (co-op, rivals, adversarial) behaves as described in §4 |
@@ -255,6 +291,10 @@ player" or "this player":
 - **Save tests:** world and player file round trips, migration of old
   saves, backups.
 - The existing 9 suites keep running in single-player (loopback) mode.
+- `tests/test_net_shared.gd` (M2.3) is the two-world version: this test is
+  one player and `tests/net_world_bot.gd` (a second process with its own
+  world, following commands the test writes as files) is the other. A
+  `--debug-regrow <k>` server flag speeds regrowth up for it.
 
 ## 11. Risks
 - **Prediction feel** is the hard part. It gets an early phase (M2.2) so

docs/SETUP_ON_NEW_MACHINE.md

@@ -34,7 +34,9 @@ It checks the Godot version, imports a fresh copy, then starts the server on
 UDP 24242 with no window. Settings live in `server.json` (its path is printed
 at start-up; on macOS it's under
 `~/Library/Application Support/Godot/app_userdata/Emberwild/server/`).
-Stop it with Ctrl+C. Players join with **Join Game** on the title screen. Over
+The shared island is saved in `worlds/server-world/` in that same folder,
+within 10 seconds of any change (and when someone leaves). Stop it with
+Ctrl+C. Players join with **Join Game** on the title screen. Over
 Tailscale, use the server machine's 100.x address or its machine name. See
 `docs/MULTIPLAYER_PLAN.md` for all the options.
 

project.godot

@@ -27,6 +27,7 @@ ItemDB="*res://scripts/core/item_db.gd"
 Actions="*res://scripts/core/actions.gd"
 Saves="*res://scripts/core/saves.gd"
 Net="*res://scripts/net/net.gd"
+WorldNet="*res://scripts/net/world_net.gd"
 
 [display]
 

scripts/building/grave.gd

@@ -17,6 +17,8 @@ func interact(player: Node) -> void:
 	player.open_inventory(self)
 
 func _on_changed() -> void:
+	if WorldNet.world != null:
+		return   # online, the server crumbles it (world_net.gd)
 	for s in inventory.slots:
 		if s != null:
 			return

scripts/core/actions.gd

@@ -53,6 +53,12 @@ func _give(player: Node, id: String, n: int) -> int:
 		notify.emit("Inventory full")
 	return got
 
+## Playing on a server: changes to the island go to it (world_net.gd), and
+## come back to everyone, us included. Our own inventory and stats stay here
+## until M2.4.
+func _online() -> bool:
+	return WorldNet.is_client()
+
 func _in_reach(player: Node3D, target: Node3D, extra: float = 0.0) -> bool:
 	return player.global_position.distance_to(target.global_position) <= REACH + 2.5 + extra
 
@@ -104,6 +110,12 @@ func pickup(player: Node3D, pickup_node: Node3D) -> bool:
 	if not is_instance_valid(pickup_node) or not _in_reach(player, pickup_node):
 		return false
 	var id: String = pickup_node.item_id
+	if _online():
+		if player.inventory.space_for(id) < 1:
+			notify.emit("Inventory full")
+			return false
+		WorldNet.take(pickup_node)   # first come, first served: the server decides
+		return true
 	if _give(player, id, pickup_node.amount) <= 0:
 		return false
 	pickup_node.collected()
@@ -123,6 +135,9 @@ func harvest_hit(player: Node3D, node: Node3D, hit_point: Vector3) -> bool:
 	if not player.survival.use_stamina(6.0):
 		notify.emit("Too tired")
 		return false
+	if _online():
+		WorldNet.hit(node, float(tool.get("damage", 1.0)), hit_point)
+		return true
 	var drops: Dictionary = node.hit(float(tool.get("damage", 1.0)), hit_point, player.global_position)
 	for id in drops:
 		_give(player, id, int(drops[id]))
@@ -145,6 +160,9 @@ func place(player: Node3D, slot: int, xf: Transform3D, world: Node3D) -> bool:
 		notify.emit("Can't place that here")
 		return false
 	player.inventory.take_from(slot, 1)
+	if _online():
+		WorldNet.place(id, xf)   # (given back if the server says no)
+		return true
 	world.spawn_piece(def, xf)
 	return true
 
@@ -165,6 +183,9 @@ func dismantle(player: Node3D, piece: Node3D) -> bool:
 	if player.inventory.space_for(piece.item_id) < 1:
 		notify.emit("Inventory full")
 		return false
+	if _online():
+		WorldNet.dismantle(piece)
+		return true
 	_give(player, piece.item_id, 1)
 	piece.get_parent().get_parent().remove_piece(piece, player)
 	return true
@@ -172,6 +193,9 @@ func dismantle(player: Node3D, piece: Node3D) -> bool:
 func toggle_door(player: Node3D, door: Node3D) -> bool:
 	if not is_instance_valid(door) or not _in_reach(player, door, 1.0):
 		return false
+	if _online():
+		WorldNet.door(door)
+		return true
 	door.set_open(not door.open)
 	return true
 
@@ -353,6 +377,9 @@ func take_off(player: Node3D) -> bool:
 func forage(player: Node3D, bush: Node3D) -> bool:
 	if not is_instance_valid(bush) or not _in_reach(player, bush) or not bush.ripe():
 		return false
+	if _online():
+		WorldNet.forage(bush)
+		return true
 	var got: Dictionary = bush.harvest()
 	for id in got:
 		_give(player, id, int(got[id]))
@@ -385,7 +412,10 @@ func add_fuel(player: Node3D, fire: Node3D) -> bool:
 	for id in ["wood", "stick", "fiber"]:
 		if player.inventory.count(id) > 0:
 			player.inventory.remove(id, 1)
-			fire.add_fuel(float(ItemDB.get_item(id).get("fuel", 10)))
+			if _online():
+				WorldNet.fuel(fire, id)
+			else:
+				fire.add_fuel(float(ItemDB.get_item(id).get("fuel", 10)))
 			notify.emit("Added %s to the fire" % ItemDB.item_name(id).to_lower())
 			return true
 	notify.emit("Nothing to burn (wood or sticks)")
@@ -396,4 +426,14 @@ func add_fuel(player: Node3D, fire: Node3D) -> bool:
 func transfer(player: Node3D, from: Inventory, slot: int, to: Inventory, container: Node3D = null) -> void:
 	if container != null and not _in_reach(player, container, 1.0):
 		return
+	if _online() and container != null:
+		var s = from.get_slot(slot)
+		if s == null:
+			return
+		if from == player.inventory:
+			from.set_slot(slot, null)
+			WorldNet.chest_put(container, s)    # what doesn't fit comes back
+		else:
+			WorldNet.chest_take(container, slot, to.space_for(s.id))
+		return
 	from.quick_move(slot, to)

scripts/core/saves.gd

@@ -58,6 +58,22 @@ func create_world(world_name: String, seed: int) -> String:
 	})
 	return id
 
+## The world slot called exactly `id` (a server's world), made with `seed` if
+## it doesn't exist yet. An existing world keeps its own seed.
+func open_or_create(id: String, seed: int) -> String:
+	if not read_meta(id).is_empty():
+		var had := int(read_meta(id).get("seed", seed))
+		if had != seed:
+			print("Saves: world '%s' was made with seed %d, so it keeps it (the config says %d)" % [id, had, seed])
+		return id
+	DirAccess.make_dir_recursive_absolute(_dir(id))
+	var now := Time.get_unix_time_from_system()
+	_write_json(_dir(id).path_join("meta.json"), {
+		"name": id, "seed": seed, "created": now, "last_played": now,
+		"play_time": 0.0, "version": VERSION,
+	})
+	return id
+
 func delete_world(id: String) -> void:
 	var dir := _dir(id)
 	var d := DirAccess.open(dir)

scripts/net/net.gd

@@ -32,7 +32,7 @@ signal clock(day: int, time: float)    ## the server's time of day
 const Identity = preload("res://scripts/net/identity.gd")
 const ServerConfig = preload("res://scripts/net/server_config.gd")
 
-const PROTOCOL := 2
+const PROTOCOL := 3   ## 3: the shared world (M2.3)
 const DEFAULT_PORT := 24242
 const HANDSHAKE_TIMEOUT := 10.0
 const JOIN_TIMEOUT := 20.0             ## includes the server building its terrain on first join
@@ -62,12 +62,11 @@ var debug_latency_ms := 0.0
 var debug_jitter_ms := 0.0
 
 # Server state.
-var _terrain: Node3D                   ## the island, regenerated from the seed, for movement checks
+var _world: Node3D                     ## the shared island (world.gd in server mode)
+var _terrain: Node3D                   ## its terrain, for movement checks
 var _spawn := Vector3.ZERO
 var _states: Dictionary = {}           ## peer -> {"pos", "yaw", "pitch", "anim", "held", "t", "corr_t"}
 var server_time := 0.0                 ## seconds since the server started
-var _clock_day := 1
-var _clock_time := 8.0 / 24.0
 var _send_left := 0.0
 var _clock_left := 0.0
 # Client delay queues (debug latency): [release_ms, callable].
@@ -180,20 +179,20 @@ func start_server(config_path: String, overrides: Dictionary = {}) -> String:
 		if overrides.has(flag):
 			var v: Variant = overrides[flag]
 			config.overrides[map[flag]] = int(v) if map[flag] in ["port", "max_players", "seed"] else String(v)
-	# The island, from the seed: the same terrain every client generates.
+	# The shared island (world_net.gd): the same terrain and scenery every
-	_terrain = load("res://scripts/world/terrain.gd").new()
+	# client generates from the seed, plus everything players changed.
-	_terrain.name = "ServerTerrain"
+	_world = WorldNet.open_server_world(config)
-	_terrain.noise_seed = int(config.v("seed"))
+	_terrain = _world.terrain
-	add_child(_terrain)
 	_spawn = _terrain.find_spawn(Vector2.ZERO)
 	server_time = 0.0
-	_clock_day = 1
-	_clock_time = 8.0 / 24.0
 	_peer = ENetMultiplayerPeer.new()
 	var port := int(config.v("port"))
 	# A few spare slots so a full server can still say "server is full".
 	var err := _peer.create_server(port, int(config.v("max_players")) + 4)
 	if err != OK:
+		WorldNet.close_server_world()
+		_world = null
+		_terrain = null
 		return "Couldn't open UDP port %d (error %d). Is another server already running on it?" % [port, err]
 	multiplayer.multiplayer_peer = _peer
 	multiplayer.server_relay = false   # clients only ever talk to the server
@@ -218,9 +217,10 @@ func stop() -> void:
 	_out_q.clear()
 	_in_q.clear()
 	local_peer = 0
-	if _terrain != null:
+	if _world != null:
-		_terrain.queue_free()
+		WorldNet.close_server_world()   # saves it first
-		_terrain = null
+	_world = null
+	_terrain = null
 	if state != "offline":
 		_set_state("offline")
 
@@ -238,6 +238,7 @@ func _on_peer_disconnected(id: int) -> void:
 		players.erase(id)
 		print("[server] %s left (%d online)" % [p.name, players.size()])
 		_s2c_player_left.rpc(id)
+		WorldNet.peer_left(id)
 		players_changed.emit()
 
 func _process(delta: float) -> void:
@@ -260,20 +261,19 @@ func _process(delta: float) -> void:
 	_run_queue(_out_q)
 	_run_queue(_in_q)
 
-## The world clock runs while anyone's on (or always, if the server's set
+## The world's clock (it runs while anyone's on, or always if the server's
-## not to pause when empty).
+## set not to pause when empty: world_net.gd pauses the world). Players get
+## it every few seconds.
 func _tick_clock(delta: float) -> void:
-	if players.is_empty() and bool(config.v("pause_when_empty")):
-		return
-	_clock_time += delta / (float(config.v("day_length_minutes")) * 60.0)
-	while _clock_time >= 1.0:
-		_clock_time -= 1.0
-		_clock_day += 1
 	_clock_left -= delta
-	if _clock_left <= 0.0:
+	if _clock_left <= 0.0 and not players.is_empty():
 		_clock_left = CLOCK_INTERVAL
 		for peer in players:
-			_s2c_clock.rpc_id(peer, _clock_day, _clock_time)
+			_s2c_clock.rpc_id(peer, _world.day_night.day, _world.day_night.time)
+
+## Where a player is, as far as the server knows.
+func player_pos(peer: int) -> Vector3:
+	return _states[peer].pos if _states.has(peer) else Vector3.INF
 
 func _broadcast_snapshot() -> void:
 	if _states.is_empty():
@@ -343,8 +343,36 @@ func move_problem(from: Vector3, to: Vector3, dt: float, teleported: bool) -> St
 		return "outside the island"
 	if to.y < _terrain.sample_height(to.x, to.z) - 1.5:
 		return "underground"
+	if not teleported and _through_wall(from, to):
+		return "through a wall"
 	return ""
 
+## Whether the straight line between two positions crosses a wall, a closed
+## door or a gable (at waist height). A genuine crossing hits the wall from
+## both sides; someone a wall was built on top of can still step out of it.
+func _through_wall(from: Vector3, to: Vector3) -> bool:
+	if _world == null or from.distance_to(to) < 0.05:
+		return false
+	var space: PhysicsDirectSpaceState3D = _world.get_world_3d().direct_space_state
+	var up := Vector3(0, 0.9, 0)
+	return _wall_hit(space, from + up, to + up) and _wall_hit(space, to + up, from + up)
+
+func _wall_hit(space: PhysicsDirectSpaceState3D, a: Vector3, b: Vector3) -> bool:
+	var ex: Array[RID] = []
+	for _i in range(4):
+		var rq := PhysicsRayQueryParameters3D.create(a, b, 4, ex)   # 4: building pieces
+		var hit := space.intersect_ray(rq)
+		if hit.is_empty():
+			return false
+		var c: Object = hit.collider
+		var piece: Node = c as Node
+		while piece != null and piece.get("kind") == null:
+			piece = piece.get_parent()
+		if piece != null and String(piece.kind) in ["wall", "door", "gable"]:
+			return true
+		ex.append(hit.rid)   # a floor or roof edge: look past it
+	return false
+
 func _reject(peer: int, reason: String) -> void:
 	_pending.erase(peer)
 	print("[server] rejected peer %d: %s" % [peer, reason])
@@ -400,8 +428,9 @@ func _c2s_proof(sig: PackedByteArray) -> void:
 		"stamp": server_time, "off": INF}
 	print("[server] %s joined (id %s%s, %d/%d online)" % [name, id, ", admin" if p.admin else "",
 		players.size(), int(config.v("max_players"))])
-	var world := {"seed": int(config.v("seed")), "worldlet": String(config.v("worldlet")), "spawn": start,
+	# (The world's own seed: an existing world keeps the seed it was made with.)
-		"island_spawn": _spawn, "day": _clock_day, "time": _clock_time, "server_time": server_time}
+	var world := {"seed": int(_terrain.noise_seed), "worldlet": String(config.v("worldlet")), "spawn": start,
+		"island_spawn": _spawn, "day": _world.day_night.day, "time": _world.day_night.time, "server_time": server_time}
 	_s2c_welcome.rpc_id(peer, {"you": peer, "server": config.public_info(), "players": players, "world": world})
 	for other in players:
 		if other != peer:

scripts/net/world_net.gd

@@ -0,0 +1,626 @@
+extends Node
+## Autoload "WorldNet": the shared world (M2.3, docs/MULTIPLAYER_PLAN.md §5).
+##
+## A dedicated server runs the real world scene headless, with no player of its
+## own (world.gd `server_mode`). It owns everything in the island that changes:
+## trees and rocks (damage, felling, regrowth), pickups, berry bushes, dropped
+## items, building pieces, chests and graves, fires, doors and the clock. The
+## weather follows from the seed and the clock, so it needs no syncing.
+##
+## Clients ask; the server checks, applies and tells everyone:
+##   client -> server  _c2s_hit uid      server -> all   _s2c_node uid hp
+##   client -> server  _c2s_place item   server -> all   _s2c_piece_added {...}
+##   ...and so on for each kind of change (the _c2s_* / _s2c_* pairs below).
+## When a change earns the asker something (wood from a tree, a pickup, a
+## dismantled wall back), the server sends it to them with _s2c_give.
+##
+## Inventories, stats and crafting stay on each player's own game until M2.4,
+## so the server trusts what a client says it puts into the world (a placed
+## wall, a chest deposit) but decides everything it takes out.
+##
+## On joining, a client's world asks for a snapshot (_c2s_world) once its
+## scenery is up; from then on it gets every change, in order.
+
+const REACH := 3.2 + 2.5          ## Actions._in_reach, plus slack for latency
+const SLACK := 2.0
+const MAX_HIT := 12.0             ## no tool hits harder than this
+const FIRE_SYNC := 10.0           ## seconds between fire fuel updates
+const SAVE_AFTER := 10.0          ## seconds after a change before saving
+const FUELS := ["wood", "stick", "fiber"]
+
+var world: Node3D                 ## server: its world; client: ours while online
+var pieces: Dictionary = {}       ## net id -> piece (both sides)
+var dropped: Dictionary = {}      ## net id -> dropped pickup (both sides)
+var _next_nid := 1
+var _ready_peers: Dictionary = {} ## server: peers that have their snapshot
+var _fire_left := FIRE_SYNC
+var _blocker_left := 0.0
+var _save_left := INF             ## counting down to a save after a change
+var _chest_cb := Callable()       ## client: waiting for a chest click's result
+var chest_busy := false
+
+## Counters the tests read.
+var received := 0                 ## client: world events applied
+
+func is_server() -> bool:
+	return Net.is_server() and world != null
+
+func is_client() -> bool:
+	return Net.state == "connected" and world != null and is_instance_valid(world)
+
+# --- server: the world -----------------------------------------------------------
+
+## Loads (or creates) the server's world from its config and adds it to the
+## tree. Saves live next to server.json, in worlds/<world>/.
+func open_server_world(config: RefCounted) -> Node3D:
+	Saves.root_dir = config.path.get_base_dir().path_join("worlds")
+	var id := String(config.v("world")).validate_filename()
+	if id.is_empty():
+		id = "server-world"
+	Saves.current_id = Saves.open_or_create(id, int(config.v("seed")))
+	var w: Node3D = load("res://scenes/world.tscn").instantiate()
+	w.server_mode = true
+	w.day_length = float(config.v("day_length_minutes")) * 60.0
+	w.autosave_seconds = maxf(float(config.v("autosave_minutes")), 0.5) * 60.0
+	get_tree().root.add_child(w)
+	world = w
+	pieces.clear()
+	dropped.clear()
+	_ready_peers.clear()
+	_next_nid = 1
+	for p in w.all_pieces():
+		if p.has_meta("nid"):
+			_next_nid = maxi(_next_nid, int(p.get_meta("nid")) + 1)
+	for p in w.all_pieces():
+		if not p.has_meta("nid"):
+			p.set_meta("nid", _new_nid())
+		pieces[int(p.get_meta("nid"))] = p
+	for d in w.all_dropped():
+		if not d.has_meta("nid"):
+			d.set_meta("nid", _new_nid())
+		dropped[int(d.get_meta("nid"))] = d
+	_next_nid = maxi(_next_nid, _max_nid() + 1)
+	w.props.regrown.connect(_on_regrown)
+	var args: Dictionary = Net.parse_args(OS.get_cmdline_user_args())
+	if args.has("debug-regrow"):
+		w.props.regrow_scale = float(args["debug-regrow"])   # (tests: things grow back in seconds)
+	print("[server] world '%s' (seed %d): %d pieces, %d dropped items. Saves: %s" % [Saves.current_id,
+		w.terrain.noise_seed, pieces.size(), dropped.size(), ProjectSettings.globalize_path(Saves.root_dir)])
+	return w
+
+func close_server_world() -> void:
+	if world == null:
+		return
+	if Net.is_server() and is_instance_valid(world):
+		save()
+	if is_instance_valid(world):
+		world.queue_free()
+	world = null
+	pieces.clear()
+	dropped.clear()
+	_ready_peers.clear()
+
+func save() -> void:
+	_save_left = INF
+	if world != null and is_instance_valid(world) and world.server_mode:
+		world.save_now()
+
+func _new_nid() -> int:
+	_next_nid += 1
+	return _next_nid - 1
+
+func _max_nid() -> int:
+	var m := 0
+	for k in pieces:
+		m = maxi(m, k)
+	for k in dropped:
+		m = maxi(m, k)
+	return m
+
+## A player left: they no longer get events. Save while it's fresh.
+func peer_left(peer: int) -> void:
+	_ready_peers.erase(peer)
+	save()
+
+func _process(delta: float) -> void:
+	if not is_server():
+		return
+	# Pause the island while nobody's on (fires, regrowth, the clock).
+	var paused: bool = Net.players.is_empty() and bool(Net.config.v("pause_when_empty"))
+	world.process_mode = Node.PROCESS_MODE_DISABLED if paused else Node.PROCESS_MODE_INHERIT
+	if paused:
+		return
+	_blocker_left -= delta
+	if _blocker_left <= 0.0:
+		_blocker_left = 1.0
+		var at: Array = []
+		for peer in Net.players:
+			at.append(Net.player_pos(peer))
+		world.props.blockers = at   # nothing regrows on top of a player
+	_save_left -= delta
+	if _save_left <= 0.0:
+		_save_left = INF
+		save()
+	_fire_left -= delta
+	if _fire_left <= 0.0:
+		_fire_left = FIRE_SYNC
+		var fires: Array = []
+		for nid in pieces:
+			var p: Node3D = pieces[nid]
+			if is_instance_valid(p) and p.get("fuel") != null:
+				fires.append([nid, p.fuel])
+		if not fires.is_empty():
+			_all("_s2c_fires", [fires])
+
+## Sends to every player who has their snapshot. Any change to the island
+## also means saving soon: Ctrl+C kills Godot without a chance to save, so
+## this keeps the loss to a few seconds.
+func _all(method: String, args: Array) -> void:
+	if method != "_s2c_fires" and _save_left == INF:
+		_save_left = SAVE_AFTER
+	for peer in _ready_peers:
+		callv("rpc_id", [peer, method] + args)
+
+func _give_to(peer: int, items: Dictionary) -> void:
+	var clean := {}
+	for id in items:
+		if int(items[id]) > 0:
+			clean[id] = int(items[id])
+	if not clean.is_empty():
+		_s2c_give.rpc_id(peer, clean)
+
+func _tell(peer: int, text: String) -> void:
+	_s2c_notify.rpc_id(peer, text)
+
+## The asker, if they're a player in the world (else 0).
+func _asker() -> int:
+	var peer := multiplayer.get_remote_sender_id()
+	if not is_server() or not _ready_peers.has(peer):
+		return 0
+	return peer
+
+func _near(peer: int, at: Vector3, r: float) -> bool:
+	return Net.player_pos(peer).distance_to(at) <= r + SLACK
+
+func _piece(nid: int) -> Node3D:
+	var p: Node3D = pieces.get(nid)
+	if p == null or not is_instance_valid(p) or p.is_queued_for_deletion():
+		pieces.erase(nid)
+		return null
+	return p
+
+func _entry(p: Node3D) -> Dictionary:
+	return world.piece_entry(p)
+
+static func _clean_stack(s: Variant) -> Variant:
+	if not s is Dictionary:
+		return null
+	var id := String(s.get("id", ""))
+	var n := int(s.get("count", 0))
+	if ItemDB.get_item(id).is_empty() or n <= 0:
+		return null
+	return {"id": id, "count": mini(n, ItemDB.stack_size(id))}
+
+static func _empty(inv: Inventory) -> bool:
+	for s in inv.slots:
+		if s != null:
+			return false
+	return true
+
+# --- client -> server -------------------------------------------------------------
+
+@rpc("any_peer", "call_remote", "reliable")
+func _c2s_world() -> void:
+	var peer := multiplayer.get_remote_sender_id()
+	if not is_server() or not Net.players.has(peer):
+		return
+	_ready_peers[peer] = true
+	_s2c_world.rpc_id(peer, world.collect_shared())
+
+@rpc("any_peer", "call_remote", "reliable")
+func _c2s_hit(uid: String, damage: float, point: Vector3) -> void:
+	var peer := _asker()
+	var n: Node3D = world.props.resource_nodes.get(uid) if peer != 0 else null
+	if n == null or not is_instance_valid(n) or n.depleted:
+		return
+	if not _near(peer, point, 3.2 + 1.0) or point.distance_to(n.global_position) > 6.0:
+		return
+	var from: Vector3 = Net.player_pos(peer)
+	var drops: Dictionary = n.hit(clampf(damage, 0.0, MAX_HIT), point, from)
+	_give_to(peer, drops)
+	_all("_s2c_node", [uid, n.hp, point, from])
+
+@rpc("any_peer", "call_remote", "reliable")
+func _c2s_take(key: String) -> void:
+	var peer := _asker()
+	if peer == 0:
+		return
+	var pk: Node3D = _find_pickup(key)
+	if pk == null or pk.taken or not _near(peer, pk.global_position, REACH):
+		return
+	var got := {pk.item_id: pk.amount}
+	if key.begins_with("#"):
+		dropped.erase(int(key.substr(1)))
+	pk.collected()
+	_give_to(peer, got)
+	_all("_s2c_taken", [key])
+
+func _find_pickup(key: String) -> Node3D:
+	var pk: Node3D
+	if key.begins_with("#"):
+		pk = dropped.get(int(key.substr(1)))
+	else:
+		pk = world.props.pickups.get(key) if world != null else null
+	return pk if pk != null and is_instance_valid(pk) else null
+
+@rpc("any_peer", "call_remote", "reliable")
+func _c2s_forage(uid: String) -> void:
+	var peer := _asker()
+	var bush: Node3D = world.props.forage.get(uid) if peer != 0 else null
+	if bush == null or not bush.ripe() or not _near(peer, bush.global_position, REACH):
+		return
+	_give_to(peer, bush.harvest())
+	_all("_s2c_forage", [uid, bush.regrow_left])
+
+## Places `item` at `xf`. The client has already taken it out of its
+## inventory: if it can't go here, it's given back. A grave carries what the
+## player was holding when they died.
+@rpc("any_peer", "call_remote", "reliable")
+func _c2s_place(item: String, xf: Transform3D, contents: Array) -> void:
+	var peer := _asker()
+	if peer == 0:
+		return
+	var def: Dictionary = ItemDB.get_item(item)
+	if def.is_empty() or not def.has("place"):
+		return
+	# (A grave can be further off: drowning puts it on the nearest shore.)
+	var ok := xf.origin.is_finite() and _near(peer, xf.origin, 40.0 if item == "grave" else 8.0)
+	if item == "grave":
+		ok = ok and not contents.is_empty()
+	else:
+		ok = ok and world.placement_valid(def, xf)
+	if not ok:
+		if item != "grave":
+			_give_to(peer, {item: 1})
+			_tell(peer, "Can't place that here")
+		return
+	var p: Node3D = world.spawn_piece(def, xf.orthonormalized())
+	if item == "grave" and p.get("inventory") != null:
+		var clean: Array = []
+		for s in contents.slice(0, p.inventory.size()):
+			clean.append(_clean_stack(s))
+		p.inventory.load_data(clean)
+	p.set_meta("nid", _new_nid())
+	pieces[int(p.get_meta("nid"))] = p
+	_all("_s2c_piece_added", [_entry(p)])
+
+@rpc("any_peer", "call_remote", "reliable")
+func _c2s_dismantle(nid: int) -> void:
+	var peer := _asker()
+	var p: Node3D = _piece(nid) if peer != 0 else null
+	if p == null or not _near(peer, p.global_position, 8.0) or p.item_id == "grave":
+		return
+	var why: String = p.dismantle_block_reason()
+	if not why.is_empty():
+		_tell(peer, why)
+		return
+	# Whatever loses its support collapses: those come back to you too.
+	var items := {}
+	for k in pieces:
+		if _piece(k) != null:
+			items[k] = pieces[k].item_id
+	world.remove_piece(p, null)
+	var gone: Array = []
+	var fell: Array = []
+	var refund := {}
+	for k in items:
+		if _piece(k) == null:
+			gone.append(k)
+			refund[items[k]] = refund.get(items[k], 0) + 1
+			if k != nid:
+				fell.append(k)
+	_all("_s2c_pieces_removed", [gone, fell])
+	_give_to(peer, refund)
+
+@rpc("any_peer", "call_remote", "reliable")
+func _c2s_door(nid: int) -> void:
+	var peer := _asker()
+	var p: Node3D = _piece(nid) if peer != 0 else null
+	if p == null or p.get("open") == null or not _near(peer, p.global_position, REACH + 1.0):
+		return
+	p.set_open(not p.open)
+	_all("_s2c_piece_state", [nid, p.save_extra()])
+
+@rpc("any_peer", "call_remote", "reliable")
+func _c2s_fuel(nid: int, item: String) -> void:
+	var peer := _asker()
+	if peer == 0 or not item in FUELS:
+		return
+	var p := _piece(nid)
+	if p == null or p.get("fuel") == null or not _near(peer, p.global_position, REACH) \
+			or p.fuel >= p.MAX_FUEL - 1.0:
+		_give_to(peer, {item: 1})
+		return
+	p.add_fuel(float(ItemDB.get_item(item).get("fuel", 10)))
+	_all("_s2c_piece_state", [nid, p.save_extra()])
+
+## A click on a chest slot while holding `cursor`: the same as clicking in
+## your own inventory (pick up, put down, swap). The new cursor comes back.
+@rpc("any_peer", "call_remote", "reliable")
+func _c2s_chest_click(nid: int, slot: int, cursor: Variant, right: bool) -> void:
+	var peer := _asker()
+	if peer == 0:
+		return
+	var c: Variant = _clean_stack(cursor)
+	var p := _piece(nid)
+	if p == null or p.get("inventory") == null or slot < 0 or slot >= p.inventory.size() \
+			or not _near(peer, p.global_position, REACH + 1.0):
+		_s2c_cursor.rpc_id(peer, c)   # nothing happened: keep what you were holding
+		return
+	var res: Variant = p.inventory.click(slot, c, right)
+	_s2c_cursor.rpc_id(peer, res)
+	_chest_changed(nid, p)
+
+## Shift-click from your inventory: as much of `stack` as fits goes in, the
+## rest comes back.
+@rpc("any_peer", "call_remote", "reliable")
+func _c2s_chest_put(nid: int, stack: Variant) -> void:
+	var peer := _asker()
+	var s: Variant = _clean_stack(stack)
+	if peer == 0 or s == null:
+		return
+	var p := _piece(nid)
+	if p == null or p.get("inventory") == null or not _near(peer, p.global_position, REACH + 1.0):
+		_give_to(peer, {s.id: s.count})
+		return
+	var left: int = p.inventory.add(s.id, s.count)
+	_give_to(peer, {s.id: left})
+	_chest_changed(nid, p)
+
+## Shift-click on a chest slot: up to `room` of it comes to you.
+@rpc("any_peer", "call_remote", "reliable")
+func _c2s_chest_take(nid: int, slot: int, room: int) -> void:
+	var peer := _asker()
+	var p: Node3D = _piece(nid) if peer != 0 else null
+	if p == null or p.get("inventory") == null or slot < 0 or slot >= p.inventory.size() or room <= 0 \
+			or not _near(peer, p.global_position, REACH + 1.0):
+		return
+	var s: Variant = p.inventory.get_slot(slot)
+	if s == null:
+		return
+	var id: String = s.id
+	var n: int = p.inventory.take_from(slot, room)
+	_give_to(peer, {id: n})
+	_chest_changed(nid, p)
+
+func _chest_changed(nid: int, p: Node3D) -> void:
+	_all("_s2c_chest", [nid, p.inventory.to_data()])
+	# An emptied grave crumbles.
+	if p.item_id == "grave" and _empty(p.inventory):
+		world.remove_piece(p, null)
+		pieces.erase(nid)
+		_all("_s2c_pieces_removed", [[nid], []])
+
+## Something the player put down in the world: an arrow that landed, a fish
+## that didn't fit. Anyone can pick it up.
+@rpc("any_peer", "call_remote", "reliable")
+func _c2s_drop(item: String, count: int, xf: Transform3D) -> void:
+	var peer := _asker()
+	if peer == 0 or ItemDB.get_item(item).is_empty() or count <= 0 or count > 999 \
+			or not xf.origin.is_finite() or not _near(peer, xf.origin, 60.0):
+		return   # (60 m: an arrow can land a long way off)
+	var d: Node3D = world.drop_item(item, count, xf.orthonormalized())
+	d.set_meta("nid", _new_nid())
+	dropped[int(d.get_meta("nid"))] = d
+	_all("_s2c_dropped", [world.dropped_entry(d)])
+
+func _on_regrown(uid: String) -> void:
+	_all("_s2c_regrown", [uid])
+
+# --- client: asking ----------------------------------------------------------------
+
+## Our world is up: ask for the shared state.
+func join_world(w: Node3D) -> void:
+	world = w
+	pieces.clear()
+	dropped.clear()
+	chest_busy = false
+	_chest_cb = Callable()
+	received = 0
+	_c2s_world.rpc_id(1)
+
+func leave_world() -> void:
+	if not Net.is_server():
+		world = null
+		pieces.clear()
+		dropped.clear()
+
+func hit(node: Node3D, damage: float, point: Vector3) -> void:
+	_c2s_hit.rpc_id(1, String(node.uid), damage, point)
+
+## The key the server knows a pickup by: its scenery id, or "#<net id>".
+func pickup_key(pk: Node3D) -> String:
+	return "#%d" % int(pk.get_meta("nid")) if pk.has_meta("nid") else String(pk.uid)
+
+func take(pk: Node3D) -> void:
+	_c2s_take.rpc_id(1, pickup_key(pk))
+
+func forage(bush: Node3D) -> void:
+	_c2s_forage.rpc_id(1, String(bush.uid))
+
+func place(item: String, xf: Transform3D, contents: Array = []) -> void:
+	_c2s_place.rpc_id(1, item, xf, contents)
+
+static func nid(p: Node3D) -> int:
+	return int(p.get_meta("nid", 0))
+
+func dismantle(p: Node3D) -> void:
+	_c2s_dismantle.rpc_id(1, nid(p))
+
+func door(p: Node3D) -> void:
+	_c2s_door.rpc_id(1, nid(p))
+
+func fuel(p: Node3D, item: String) -> void:
+	_c2s_fuel.rpc_id(1, nid(p), item)
+
+## `done(cursor)` gets what you're holding afterwards.
+func chest_click(p: Node3D, slot: int, cursor: Variant, right: bool, done: Callable) -> void:
+	chest_busy = true
+	_chest_cb = done
+	_c2s_chest_click.rpc_id(1, nid(p), slot, cursor, right)
+
+func chest_put(p: Node3D, stack: Dictionary) -> void:
+	_c2s_chest_put.rpc_id(1, nid(p), stack)
+
+func chest_take(p: Node3D, slot: int, room: int) -> void:
+	_c2s_chest_take.rpc_id(1, nid(p), slot, room)
+
+func drop(item: String, count: int, xf: Transform3D) -> void:
+	_c2s_drop.rpc_id(1, item, count, xf)
+
+# --- server -> client ------------------------------------------------------------
+
+@rpc("authority", "call_remote", "reliable")
+func _s2c_world(state: Dictionary) -> void:
+	if not is_client():
+		return
+	world.apply_shared(state)
+	pieces.clear()
+	dropped.clear()
+	for p in world.all_pieces():
+		if p.has_meta("nid"):
+			pieces[int(p.get_meta("nid"))] = p
+	for d in world.all_dropped():
+		if d.has_meta("nid"):
+			dropped[int(d.get_meta("nid"))] = d
+	received += 1
+
+@rpc("authority", "call_remote", "reliable")
+func _s2c_node(uid: String, hp: float, point: Vector3, from: Vector3) -> void:
+	if not is_client():
+		return
+	var n: Node3D = world.props.resource_nodes.get(uid)
+	if n != null and is_instance_valid(n):
+		n.apply_remote(hp, point, from)
+		received += 1
+
+@rpc("authority", "call_remote", "reliable")
+func _s2c_regrown(uid: String) -> void:
+	if not is_client():
+		return
+	var n: Node3D = world.props.pickups.get(uid, world.props.resource_nodes.get(uid))
+	if n != null and is_instance_valid(n):
+		world.props.regrow.erase(uid)
+		n.regrow()
+		received += 1
+
+@rpc("authority", "call_remote", "reliable")
+func _s2c_taken(key: String) -> void:
+	if not is_client():
+		return
+	var pk := _find_pickup(key)
+	if key.begins_with("#"):
+		dropped.erase(int(key.substr(1)))
+	if pk != null:
+		pk.collected()
+		received += 1
+
+@rpc("authority", "call_remote", "reliable")
+func _s2c_forage(uid: String, left: float) -> void:
+	if not is_client():
+		return
+	var bush: Node3D = world.props.forage.get(uid)
+	if bush != null:
+		bush.restore(left)
+		received += 1
+
+@rpc("authority", "call_remote", "reliable")
+func _s2c_piece_added(e: Dictionary) -> void:
+	if not is_client():
+		return
+	var p: Node3D = world.add_piece_entry(e)
+	if p != null:
+		pieces[int(e.nid)] = p
+		received += 1
+
+@rpc("authority", "call_remote", "reliable")
+func _s2c_pieces_removed(nids: Array, fell: Array) -> void:
+	if not is_client():
+		return
+	var gone: Array = []
+	for k in nids:
+		var p: Node3D = pieces.get(int(k))
+		pieces.erase(int(k))
+		if p != null and is_instance_valid(p):
+			gone.append(p)
+	var collapsed: Array = []
+	for k in fell:
+		collapsed.append(int(k))
+	world.remove_pieces_net(gone, collapsed)
+	received += 1
+
+@rpc("authority", "call_remote", "reliable")
+func _s2c_piece_state(nid_: int, extra: Dictionary) -> void:
+	if not is_client():
+		return
+	var p: Node3D = pieces.get(nid_)
+	if p == null or not is_instance_valid(p):
+		return
+	if extra.has("open") and p.has_method("set_open"):
+		p.set_open(bool(extra.open))
+	elif p.has_method("load_extra"):
+		p.load_extra(extra)
+	received += 1
+
+@rpc("authority", "call_remote", "reliable")
+func _s2c_fires(fires: Array) -> void:
+	if not is_client():
+		return
+	for f in fires:
+		var p: Node3D = pieces.get(int(f[0]))
+		if p != null and is_instance_valid(p) and p.has_method("load_extra"):
+			p.load_extra({"fuel": float(f[1])})
+
+@rpc("authority", "call_remote", "reliable")
+func _s2c_chest(nid_: int, data: Array) -> void:
+	if not is_client():
+		return
+	var p: Node3D = pieces.get(nid_)
+	if p != null and is_instance_valid(p) and p.get("inventory") != null:
+		p.inventory.load_data(data)
+		received += 1
+
+@rpc("authority", "call_remote", "reliable")
+func _s2c_dropped(e: Dictionary) -> void:
+	if not is_client():
+		return
+	var d: Node3D = world.add_dropped_entry(e)
+	if d != null:
+		dropped[int(e.nid)] = d
+		received += 1
+
+## Items the server decided we earned. Anything that doesn't fit goes back
+## on the ground at our feet (for anyone to pick up).
+@rpc("authority", "call_remote", "reliable")
+func _s2c_give(items: Dictionary) -> void:
+	if not is_client():
+		return
+	for id in items:
+		var n := int(items[id])
+		var got: int = Actions._give(world.player, String(id), n)
+		if got < n:
+			drop(String(id), n - got, Transform3D(Basis(), world.player.global_position + Vector3(0, 0.1, 0)))
+
+@rpc("authority", "call_remote", "reliable")
+func _s2c_cursor(stack: Variant) -> void:
+	chest_busy = false
+	var cb := _chest_cb
+	_chest_cb = Callable()
+	if cb.is_valid():
+		cb.call(stack)
+	elif stack != null and is_client():
+		_s2c_give({stack.id: stack.count})
+
+@rpc("authority", "call_remote", "reliable")
+func _s2c_notify(text: String) -> void:
+	Actions.notify.emit(text)

scripts/ui/inventory_screen.gd

@@ -144,8 +144,12 @@ func open(chest: Node) -> void:
 func close() -> void:
 	if _cursor != null:
 		var left: int = player.inventory.add(_cursor.id, _cursor.count)
-		if left > 0 and container != null:
+		if left > 0 and container != null and is_instance_valid(container):
-			left = container.inventory.add(_cursor.id, left)
+			if WorldNet.is_client():
+				WorldNet.chest_put(container, {"id": _cursor.id, "count": left})
+				left = 0
+			else:
+				left = container.inventory.add(_cursor.id, left)
 		_cursor = null
 	if container != null and is_instance_valid(container) and container.inventory.changed.is_connected(_refresh):
 		container.inventory.changed.disconnect(_refresh)
@@ -201,10 +205,28 @@ func _on_chest_slot(i: int, right: bool, shift: bool) -> void:
 		return
 	if shift:
 		Actions.transfer(player, container.inventory, i, player.inventory, container)
+	elif WorldNet.is_client():
+		# A shared chest: the server does the click (someone else may be in
+		# it too) and hands back what we're holding.
+		if WorldNet.chest_busy:
+			return
+		var held = _cursor
+		_cursor = null
+		WorldNet.chest_click(container, i, held, right, _on_chest_cursor)
 	else:
 		_cursor = container.inventory.click(i, _cursor, right)
 	_refresh()
 
+func _on_chest_cursor(stack) -> void:
+	if visible:
+		_cursor = stack
+		_refresh()
+	elif stack != null:
+		# Closed in the meantime: into our bag (or the ground).
+		var left: int = player.inventory.add(stack.id, stack.count)
+		if left > 0:
+			player.get_parent().drop_item(stack.id, left, Transform3D(Basis(), player.global_position + Vector3(0, 0.1, 0)))
+
 func _refresh() -> void:
 	if player == null:
 		return

scripts/world/props.gd

@@ -45,6 +45,12 @@ var forage: Dictionary = {}           ## uid -> berry bush (forage.gd)
 ## Regrowth: uid -> seconds until a felled tree, mined boulder or picked-up
 ## item comes back. Saved with the world. Bushes keep their own timers.
 var regrow: Dictionary = {}
+## Off on a client playing online: the server says when things grow back.
+var regrow_enabled := true
+## Other places nothing may regrow on top of (a server's players).
+var blockers: Array = []
+var regrow_scale := 1.0               ## test hook: a server started with --debug-regrow <k>
+signal regrown(uid: String)
 const REGROW_SECONDS := {"tree": 2400.0, "rock": 3600.0, "pickup": 900.0}
 const REGROW_RETRY := 120.0           ## blocked (player or a building nearby): try again later
 var _regrow_tick := 0.0
@@ -125,15 +131,15 @@ func _regrow_kind(uid: String) -> String:
 	return resource_nodes[uid].kind
 
 func _on_depleted(node: Node) -> void:
-	regrow[node.uid] = REGROW_SECONDS[node.kind]
+	regrow[node.uid] = REGROW_SECONDS[node.kind] * regrow_scale
 
 func _on_taken(pk: Node) -> void:
-	regrow[pk.uid] = REGROW_SECONDS["pickup"]
+	regrow[pk.uid] = REGROW_SECONDS["pickup"] * regrow_scale
 
 ## Advances regrowth timers by `secs` (every second while playing, or in one
 ## go when you sleep).
 func skip_time(secs: float) -> void:
-	for uid in regrow.keys():
+	for uid in regrow.keys() if regrow_enabled else []:
 		regrow[uid] -= secs
 		if regrow[uid] <= 0.0:
 			_try_regrow(uid)
@@ -148,12 +154,15 @@ func _try_regrow(uid: String) -> void:
 		regrow.erase(uid)
 		return
 	var r := 0.5 if pickups.has(uid) else 1.4
-	if _player != null and _player.global_position.distance_to(node.global_position) < r + 3.0 \
+	var blocked := _player != null and _player.global_position.distance_to(node.global_position) < r + 3.0
-			or _built_over(node.global_position, r):
+	for b in blockers:
-		regrow[uid] = REGROW_RETRY
+		blocked = blocked or (b as Vector3).distance_to(node.global_position) < r + 3.0
+	if blocked or _built_over(node.global_position, r):
+		regrow[uid] = REGROW_RETRY * regrow_scale
 		return
 	regrow.erase(uid)
 	node.regrow()
+	regrown.emit(uid)
 
 ## Something built (or being built) where a tree or rock would come back.
 func _built_over(pos: Vector3, r: float) -> bool:
@@ -179,10 +188,10 @@ func restore_regrow(saved: Dictionary) -> void:
 			regrow[uid] = float(saved[uid])
 	for uid in resource_nodes:
 		if resource_nodes[uid].depleted and not regrow.has(uid):
-			regrow[uid] = REGROW_SECONDS[resource_nodes[uid].kind]
+			regrow[uid] = REGROW_SECONDS[resource_nodes[uid].kind] * regrow_scale
 	for uid in pickups:
 		if pickups[uid].taken and not regrow.has(uid):
-			regrow[uid] = REGROW_SECONDS["pickup"]
+			regrow[uid] = REGROW_SECONDS["pickup"] * regrow_scale
 
 # --- materials --------------------------------------------------------------
 

scripts/world/resource_node.gd

@@ -56,15 +56,26 @@ func interact_prompt(player: Node) -> String:
 ## Applies one hit. Returns the items earned by this hit.
 func hit(damage: float, point: Vector3, from: Vector3) -> Dictionary:
 	var out := {}
-	hp -= damage
 	for id in drops_per_hit:
 		out[id] = drops_per_hit[id]
-	_burst(point, chip_color, 14)
+	if hp - damage <= 0.0:
-	if hp <= 0.0:
-		depleted = true
 		for id in drops_final:
 			var r: Array = drops_final[id]
 			out[id] = out.get(id, 0) + rng.randi_range(int(r[0]), int(r[1]))
+	_show_hit(hp - damage, point, from)
+	return out
+
+## A hit someone else's game reported, via the server (world_net.gd): the
+## same chips, shake and fall, with no drops.
+func apply_remote(new_hp: float, point: Vector3, from: Vector3) -> void:
+	if not depleted:
+		_show_hit(new_hp, point, from)
+
+func _show_hit(new_hp: float, point: Vector3, from: Vector3) -> void:
+	hp = new_hp
+	_burst(point, chip_color, 14)
+	if hp <= 0.0:
+		depleted = true
 		_deplete(from)
 	else:
 		_shake = 1.0
@@ -73,7 +84,6 @@ func hit(damage: float, point: Vector3, from: Vector3) -> Dictionary:
 		_shake_axis = away.normalized().cross(Vector3.UP) if away.length() > 0.01 else Vector3.RIGHT
 		if kind == "rock":
 			_set_instance(_rock_xf())
-	return out
 
 func _process(delta: float) -> void:
 	if _shake <= 0.0 or depleted:

scripts/world/world.gd

@@ -33,6 +33,12 @@ const AUTOSAVE_SECONDS := 120.0
 ## Set by the title screen before adding the world: no player, no HUD, no
 ## saving, just a slow camera flight over the island as a menu backdrop.
 var menu_mode := false
+## Set by WorldNet on a dedicated server: the shared island with nobody of its
+## own in it (no player, HUD, animals or effects). It saves to the server's
+## world slot. See world_net.gd.
+var server_mode := false
+var day_length := 1200.0           ## seconds per day (a server sets its own)
+var autosave_seconds := AUTOSAVE_SECONDS
 
 var _spawn := Vector3.ZERO
 var _spawn_yaw := 0.0
@@ -61,11 +67,15 @@ func is_online() -> bool:
 var _loading := false           ## applying a save: defer support recompute
 
 func _ready() -> void:
+	_autosave_left = autosave_seconds
 	_pieces = Node3D.new()
 	_pieces.name = "Pieces"
 	add_child(_pieces)
 	day_night = preload("res://scripts/world/day_night.gd").new()
 	day_night.name = "DayNight"
+	if is_online() and Net.server_info.has("day_length_minutes"):
+		day_length = float(Net.server_info.day_length_minutes) * 60.0   # same days, same weather
+	day_night.day_length = day_length
 	add_child(day_night)
 	day_night.setup(sun, $WorldEnvironment.environment)
 	weather = preload("res://scripts/world/weather.gd").new()
@@ -86,7 +96,15 @@ func _ready() -> void:
 	creatures.name = "Creatures"
 	creatures.enabled = false   # until the scenery is placed
 	add_child(creatures)
-	if not menu_mode and DisplayServer.get_name() != "headless":
+	if server_mode:
+		# Nobody of our own: the player node stays, parked out of the way and
+		# switched off, because a few shared functions expect one.
+		player.process_mode = Node.PROCESS_MODE_DISABLED
+		player.collision_layer = 0
+		player.position = Vector3(0, -500, 0)
+		player.get_node("Camera3D").current = false
+		$HUD.visible = false
+	elif not menu_mode and DisplayServer.get_name() != "headless":
 		weather_fx = preload("res://scripts/world/weather_fx.gd").new()
 		weather_fx.name = "WeatherFX"
 		add_child(weather_fx)
@@ -101,13 +119,13 @@ func _ready() -> void:
 		add_child(_menu_cam)
 		_menu_cam.current = true
 		$HUD.visible = false
-	elif DisplayServer.get_name() != "headless":
+	elif DisplayServer.get_name() != "headless" and not server_mode:
 		hud = preload("res://scripts/ui/hud.gd").new()
 		add_child(hud)
 		hud.bind(player)
-	if not menu_mode:
+	if not menu_mode and not server_mode:
 		player.survival.died.connect(_on_player_died)
-	if Saves.has_world() and not menu_mode:
+	if Saves.has_world() and not menu_mode and not server_mode:
 		# Save on window close instead of quitting straight away.
 		get_tree().auto_accept_quit = false
 	player.set_physics_process(false)
@@ -158,8 +176,12 @@ func _on_player_died() -> void:
 		if st != null:
 			has_items = true
 	if has_items:
-		var grave := spawn_piece(ItemDB.get_item("grave"), Transform3D(Basis(Vector3.UP, player.rotation.y), pos))
+		var gxf := Transform3D(Basis(Vector3.UP, player.rotation.y), pos)
-		grave.inventory.load_data(player.inventory.to_data())
+		if net_sync != null:
+			WorldNet.place("grave", gxf, player.inventory.to_data())   # the server puts it in the shared world
+		else:
+			var grave := spawn_piece(ItemDB.get_item("grave"), gxf)
+			grave.inventory.load_data(player.inventory.to_data())
 		player.inventory.load_data(Inventory.new(player.inventory.size()).to_data())
 	if hud != null:
 		hud.close_screens()
@@ -197,6 +219,8 @@ func _respawn_at_bed(bed: Node3D) -> void:
 
 ## Why you can't sleep in `bed` right now ("" = you can).
 func sleep_block_reason(bed: Node3D) -> String:
+	if is_online():
+		return "Sleeping on a server isn't in yet (everyone would have to agree)"
 	var h: float = day_night.hours()
 	if h > 5.5 and h < 19.5:
 		return "You can only sleep at night (after 19:30)"
@@ -255,6 +279,12 @@ func _on_terrain_ready() -> void:
 	print("[world] scenery placed in %d ms" % (Time.get_ticks_msec() - t0))
 	if menu_mode:
 		return
+	if server_mode:
+		if Saves.has_world():
+			var saved: Dictionary = Saves.load_state(Saves.current_id)
+			if not saved.is_empty():
+				apply_save(saved)
+		return   # no player, no animals (the server runs those in M2.5)
 	_respawn()
 	if Saves.has_world():
 		var state: Dictionary = Saves.load_state(Saves.current_id)
@@ -301,15 +331,25 @@ func _process(delta: float) -> void:
 ## Writes the current game to the active world slot. Returns false if this
 ## session isn't tied to a slot (e.g. running world.tscn directly).
 func save_now() -> bool:
-	_autosave_left = AUTOSAVE_SECONDS
+	_autosave_left = autosave_seconds
 	if not Saves.has_world():
 		return false
 	var ok: bool = Saves.save_state(Saves.current_id, collect_save(), _session_time)
 	if ok:
 		_session_time = 0.0
-	Actions.notify.emit("Game saved" if ok else "Save FAILED")
+	if server_mode:
+		if not ok:
+			printerr("[server] saving the world FAILED")
+	else:
+		Actions.notify.emit("Game saved" if ok else "Save FAILED")
 	return ok
 
+## A server's world saves as it closes, however the server stops (Ctrl+C
+## included), unless it has just saved.
+func _exit_tree() -> void:
+	if server_mode and Saves.has_world() and _session_time > 0.0:
+		save_now()
+
 func _notification(what: int) -> void:
 	if what != NOTIFICATION_WM_CLOSE_REQUEST or menu_mode:
 		return
@@ -349,20 +389,13 @@ func collect_save() -> Dictionary:
 		if not is_instance_valid(pk) or pk.taken:
 			taken.append(uid)
 	var dropped: Array = []
-	for d in _dropped.get_children():
+	for d in all_dropped():
-		if d.is_queued_for_deletion() or d.taken:
+		dropped.append(dropped_entry(d))
-			continue
-		dropped.append({"item": d.item_id, "count": d.amount, "xf": _xf_to_array(d.global_transform)})
 	var pieces: Array = []
-	for piece in _pieces.get_children():
+	for piece in all_pieces():
-		if piece.is_queued_for_deletion():
+		pieces.append(piece_entry(piece))
-			continue
+	if server_mode:
-		var entry := {"item": piece.item_id, "xf": _xf_to_array(piece.global_transform)}
+		return _shared_state(harvested, regrow, taken, dropped, pieces)
-		if piece.get("inventory") != null:
-			entry["inventory"] = piece.inventory.to_data()
-		if piece.has_method("save_extra"):
-			entry["extra"] = piece.save_extra()
-		pieces.append(entry)
 	return {
 		"player": {
 			"pos": [player.global_position.x, player.global_position.y, player.global_position.z],
@@ -383,22 +416,107 @@ func collect_save() -> Dictionary:
 		"pieces": pieces,
 	}
 
-func apply_save(s: Dictionary) -> void:
+func _shared_state(harvested: Dictionary, regrow: Dictionary, taken: Array, dropped: Array, pieces: Array) -> Dictionary:
-	var p: Dictionary = s.get("player", {})
+	return {
+		"dropped": dropped,
+		"time": {"day": day_night.day, "time": day_night.time},
+		"forage_regrow": regrow,
+		"regrow": props.regrow.duplicate(),
+		"harvested": harvested,
+		"pickups_taken": taken,
+		"pieces": pieces,
+	}
+
+## The live pieces (placed and not being removed).
+func all_pieces() -> Array:
+	return _pieces.get_children().filter(func(p): return not p.is_queued_for_deletion())
+
+func all_dropped() -> Array:
+	return _dropped.get_children().filter(func(d): return not d.is_queued_for_deletion() and not d.taken)
+
+## One piece as saved (and as sent to players): its item, where it is, what's
+## in it, its state (fuel, door open), and its net id if it has one.
+func piece_entry(piece: Node3D) -> Dictionary:
+	var entry := {"item": piece.item_id, "xf": _xf_to_array(piece.global_transform)}
+	if piece.get("inventory") != null:
+		entry["inventory"] = piece.inventory.to_data()
+	if piece.has_method("save_extra"):
+		entry["extra"] = piece.save_extra()
+	if piece.has_meta("nid"):
+		entry["nid"] = int(piece.get_meta("nid"))
+	return entry
+
+func dropped_entry(d: Node3D) -> Dictionary:
+	var e := {"item": d.item_id, "count": d.amount, "xf": _xf_to_array(d.global_transform)}
+	if d.has_meta("nid"):
+		e["nid"] = int(d.get_meta("nid"))
+	return e
+
+## The shared state a server sends a player who joins (everything but the
+## server's own bookkeeping).
+func collect_shared() -> Dictionary:
+	return collect_save()
+
+## A joining player's copy of the server's island.
+func apply_shared(s: Dictionary) -> void:
+	apply_save(s, false)
+	props.regrow.clear()   # the server says when things grow back
+
+func add_piece_entry(e: Dictionary) -> Node3D:
+	var def: Dictionary = ItemDB.get_item(e.get("item", ""))
+	if def.is_empty() or not def.has("place"):
+		return null
+	var piece := spawn_piece(def, _array_to_xf(e.xf))
+	if e.has("inventory") and piece.get("inventory") != null:
+		piece.inventory.load_data(e.inventory)
+	if e.has("extra") and piece.has_method("load_extra"):
+		piece.load_extra(e.extra)
+	if e.has("nid"):
+		piece.set_meta("nid", int(e.nid))
+	return piece
+
+func add_dropped_entry(e: Dictionary) -> Node3D:
+	if ItemDB.get_item(e.get("item", "")).is_empty():
+		return null
+	var d := _make_dropped(e.item, int(e.get("count", 1)), _array_to_xf(e.xf))
+	if e.has("nid"):
+		d.set_meta("nid", int(e.nid))
+	return d
+
+## Pieces the server took out (dismantled, collapsed, a grave emptied). No
+## refunds here: the server sends those to whoever did it.
+func remove_pieces_net(gone: Array, collapsed_nids: Array) -> void:
+	var any_build := false
+	for p in gone:
+		if p.item_id == "bed" and spawn_bed() == p:
+			has_bed_spawn = false
+		if p.is_in_group("build"):
+			any_build = true
+		if int(p.get_meta("nid", 0)) in collapsed_nids:
+			_collapse_fx(p)
+		_pieces.remove_child(p)
+		p.queue_free()
+	if any_build:
+		build.recompute()
+		_settle_loose_pieces()
+		_update_grass_cuts()
+
+func apply_save(s: Dictionary, with_player: bool = true) -> void:
+	var p: Dictionary = s.get("player", {}) if with_player else {}
 	if p.has("pos"):
 		player.global_position = Vector3(p.pos[0], p.pos[1] + 0.05, p.pos[2])
 		player.rotation = Vector3(0.0, float(p.get("yaw", 0.0)), 0.0)
 		player.get_node("Camera3D").rotation.x = float(p.get("pitch", 0.0))
-	if p.has("inventory"):
+	if with_player:
-		player.inventory.load_data(p.inventory)
+		if p.has("inventory"):
-	player.select(int(p.get("selected", 0)))
+			player.inventory.load_data(p.inventory)
-	if p.has("stats"):
+		player.select(int(p.get("selected", 0)))
-		player.survival.load_data(p.stats)
+		if p.has("stats"):
-	player.worn = String(p.get("worn", ""))
+			player.survival.load_data(p.stats)
-	player.worn_changed.emit()
+		player.worn = String(p.get("worn", ""))
+		player.worn_changed.emit()
 	for d in s.get("dropped", []):
-		if not ItemDB.get_item(d.get("item", "")).is_empty():
+		add_dropped_entry(d)
-			drop_item(d.item, int(d.get("count", 1)), _array_to_xf(d.xf))
 	var t: Dictionary = s.get("time", {})
 	if not t.is_empty():
 		day_night.day = int(t.get("day", 1))
@@ -424,14 +542,7 @@ func apply_save(s: Dictionary) -> void:
 	weather.snap()
 	_loading = true
 	for e in s.get("pieces", []):
-		var def: Dictionary = ItemDB.get_item(e.get("item", ""))
+		add_piece_entry(e)
-		if def.is_empty() or not def.has("place"):
-			continue
-		var piece := spawn_piece(def, _array_to_xf(e.xf))
-		if e.has("inventory") and piece.get("inventory") != null:
-			piece.inventory.load_data(e.inventory)
-		if e.has("extra") and piece.has_method("load_extra"):
-			piece.load_extra(e.extra)
 	_loading = false
 	build.recompute()   # same terrain, same pieces: nothing collapses on load
 	_update_grass_cuts()
@@ -531,14 +642,18 @@ func _go_online() -> void:
 	net_sync.setup(self)
 	Net.left.connect(_on_net_left)
 	get_tree().auto_accept_quit = false   # leave the server cleanly on window close
+	# The island's changes come from the server from now on.
+	props.regrow_enabled = false
+	WorldNet.join_world(self)
 	if hud != null:
-		var bar := UITheme.label("Online: %s  ·  you can see each other; building, gathering and animals aren't shared yet" \
+		var bar := UITheme.label("Online: %s  ·  the island is shared; your inventory isn't saved yet, and there are no animals yet" \
 			% Net.server_info.get("server_name", "server"), 14, UITheme.TEXT_DIM)
 		bar.position = Vector2(16, 40)
 		$HUD.add_child(bar)
 	Actions.notify.emit("Connected to %s" % Net.server_info.get("server_name", "the server"))
 
 func _on_net_left(_reason: String) -> void:
+	WorldNet.leave_world()
 	if is_inside_tree():
 		get_tree().paused = false
 		get_tree().auto_accept_quit = true
@@ -546,7 +661,14 @@ func _on_net_left(_reason: String) -> void:
 
 ## Leaves `count` of an item lying in the world at `xf` (an arrow stuck in a
 ## tree, a thrown spear, meat that didn't fit). Saved with the world.
+## Online, the server puts it in the shared world (and returns null here).
 func drop_item(id: String, count: int, xf: Transform3D) -> Node3D:
+	if net_sync != null:
+		WorldNet.drop(id, count, xf)
+		return null
+	return _make_dropped(id, count, xf)
+
+func _make_dropped(id: String, count: int, xf: Transform3D) -> Node3D:
 	var pk: Area3D = preload("res://scripts/world/pickup.gd").new()
 	pk.setup(id, ItemDB.mesh_for(id), ItemDB.item_material(), 0.3)
 	pk.amount = count

tests/net_world_bot.gd

@@ -0,0 +1,159 @@
+extends SceneTree
+## A second player with a real world, for tests/test_net_shared.gd. Joins,
+## loads the island like the game does, then follows commands the test
+## writes as files (so the test can line up both players' actions):
+##   <dir>/cmd_<n>.json  -> runs it ->  <dir>/res_<n>.json
+## Commands: walk, report, take, chest_take, bump, hop, leave.
+## Args (after --): --identity <dir> --name <name> --address host:port --dir <cmd dir>
+
+var net: Node
+var world: Node3D
+var player: CharacterBody3D
+var dir := ""
+var corrections := 0
+
+func _initialize() -> void:
+	_run.call_deferred()
+
+func _run() -> void:
+	net = root.get_node("Net")
+	var args: Dictionary = net.parse_args(OS.get_cmdline_user_args())
+	dir = String(args.dir)
+	var me = load("res://scripts/net/identity.gd").open(String(args.identity))
+	me.name = String(args.get("name", "Bob"))
+	net.identity = me
+	var outcome := {"v": ""}
+	net.joined.connect(func(): outcome.v = "joined")
+	net.join_failed.connect(func(r): outcome.v = "failed: " + r)
+	net.join(String(args.address))
+	var t0 := Time.get_ticks_msec()
+	while outcome.v.is_empty() and Time.get_ticks_msec() - t0 < 20000:
+		await process_frame
+	if outcome.v != "joined":
+		_write(0, {"ok": false, "why": outcome.v})
+		quit()
+		return
+	world = load("res://scenes/world.tscn").instantiate()
+	root.add_child(world)
+	for _i in range(8):
+		await physics_frame
+	player = world.player
+	player.set_physics_process(false)   # the test moves us
+	net.corrected.connect(func(_p): corrections += 1)
+	t0 = Time.get_ticks_msec()
+	while world.get_node("/root/WorldNet").received < 1 and Time.get_ticks_msec() - t0 < 10000:
+		await process_frame
+	_write(0, {"ok": true, "pos": _v(player.global_position)})
+	var n := 1
+	while net.state == "connected":
+		var path := "%s/cmd_%d.json" % [dir, n]
+		if not FileAccess.file_exists(path):
+			await create_timer(0.05).timeout
+			continue
+		await create_timer(0.05).timeout
+		var cmd: Dictionary = JSON.parse_string(FileAccess.get_file_as_string(path))
+		var res: Dictionary = await _do(cmd)
+		_write(n, res)
+		n += 1
+		if cmd.get("do") == "leave":
+			break
+	quit()
+
+func _write(n: int, d: Dictionary) -> void:
+	var f := FileAccess.open("%s/res_%d.json" % [dir, n], FileAccess.WRITE)
+	f.store_string(JSON.stringify(d))
+	f.close()
+
+static func _v(p: Vector3) -> Array:
+	return [p.x, p.y, p.z]
+
+static func _p(a: Array) -> Vector3:
+	return Vector3(a[0], a[1], a[2])
+
+func _do(cmd: Dictionary) -> Dictionary:
+	var WN: Node = root.get_node("WorldNet")
+	match String(cmd.get("do", "")):
+		"walk":
+			await walk(player, _p(cmd.to), world)
+			return {"pos": _v(player.global_position), "corrections": corrections}
+		"report":
+			return report(world, WN, cmd, corrections)
+		"take":
+			var pk: Node3D = _pickup(world, WN, String(cmd.key))
+			var ok: bool = pk != null and root.get_node("Actions").pickup(player, pk)
+			await create_timer(0.6).timeout
+			return {"asked": ok, "inv": player.inventory.to_data()}
+		"chest_take":
+			var c: Node3D = WN.pieces.get(int(cmd.nid))
+			if c == null:
+				return {"error": "no chest %d" % int(cmd.nid)}
+			root.get_node("Actions").transfer(player, c.inventory, int(cmd.slot), player.inventory, c)
+			await create_timer(0.6).timeout
+			return {"inv": player.inventory.to_data()}
+		"bump":
+			# Walk into whatever's in front, with real collisions.
+			var start := player.global_position
+			var d: Vector3 = _p(cmd.dir).normalized()
+			for _i in range(int(float(cmd.dist) / 0.1)):
+				player.move_and_collide(d * 0.1)
+				await physics_frame
+			await create_timer(0.3).timeout
+			return {"moved": Vector2(player.global_position.x - start.x, player.global_position.z - start.z).length()}
+		"hop":
+			# Cheat: step straight through to the other side.
+			var c0 := corrections
+			player.global_position = _p(cmd.to)
+			await create_timer(1.0).timeout
+			return {"corrected": corrections - c0, "pos": _v(player.global_position)}
+		"leave":
+			net.leave()
+			await create_timer(0.3).timeout
+			return {"left": true}
+	return {"error": "unknown command"}
+
+# Shared with test_net_shared.gd (it loads this script for these).
+
+## Walks (by setting positions, like the game sending its moves) at 5 m/s.
+static func walk(p: CharacterBody3D, to: Vector3, w: Node3D) -> void:
+	var tree := p.get_tree()
+	var from := p.global_position
+	var dist := Vector2(to.x - from.x, to.z - from.z).length()
+	var steps := maxi(1, int(dist / (5.0 / 60.0)))
+	for i in range(1, steps + 1):
+		var q := from.lerp(to, float(i) / steps)
+		q.y = w.terrain.sample_height(q.x, q.z) + 0.05
+		p.global_position = q
+		await tree.physics_frame
+	await tree.create_timer(0.4).timeout   # let the server hear about it
+
+static func _pickup(w: Node3D, WN: Node, key: String) -> Node3D:
+	if key.begins_with("#"):
+		return WN.dropped.get(int(key.substr(1)))
+	return w.props.pickups.get(key)
+
+static func report(w: Node3D, WN: Node, cmd: Dictionary, corr: int) -> Dictionary:
+	var out := {"nodes": {}, "pieces": {}, "taken": {}, "inv": w.player.inventory.to_data(),
+		"received": WN.received, "corrections": corr, "dropped": []}
+	for uid in cmd.get("uids", []):
+		var n: Node3D = w.props.resource_nodes.get(uid)
+		out.nodes[uid] = {"hp": n.hp, "depleted": n.depleted} if n != null else null
+	for key in cmd.get("keys", []):
+		var pk: Node3D = _pickup(w, WN, key)
+		out.taken[key] = pk == null or not is_instance_valid(pk) or pk.taken
+	for nid in WN.pieces:
+		var p: Node3D = WN.pieces[nid]
+		if p == null or not is_instance_valid(p) or p.is_queued_for_deletion():
+			continue
+		var e := {"item": p.item_id, "pos": _v(p.global_position)}
+		if p.get("inventory") != null:
+			e.inv = p.inventory.to_data()
+		if p.get("open") != null:
+			e.open = p.open
+		if p.get("fuel") != null:
+			e.fuel = p.fuel
+		out.pieces[str(nid)] = e
+	for nid in WN.dropped:
+		var d: Node3D = WN.dropped[nid]
+		if d != null and is_instance_valid(d) and not d.taken:
+			out.dropped.append({"nid": nid, "item": d.item_id, "count": d.amount})
+	return out

tests/run_all.sh

@@ -9,7 +9,7 @@ if [ ! -f .godot/global_script_class_cache.cfg ]; then
 	echo "Importing the project first (fresh copy)..."
 	godot --headless --path . --import >/dev/null 2>&1
 fi
-for t in test_survival_core test_survival_stats test_save_load test_weather_building test_creatures_combat test_wolves test_den_sites test_fishing_diet test_net_lobby test_net_world test_terrain_edges test_boundary; do
+for t in test_survival_core test_survival_stats test_save_load test_weather_building test_creatures_combat test_wolves test_den_sites test_fishing_diet test_net_lobby test_net_world test_net_shared test_terrain_edges test_boundary; do
 	extra=""
 	[ "$t" = "test_boundary" ] && extra="--fixed-fps 30"
 	# A suite that waits on a world that failed to load would hang forever,

tests/test_net_lobby.gd

@@ -207,10 +207,13 @@ func _result(path: String) -> Dictionary:
 func _sleep(s: float) -> void:
 	await create_timer(s).timeout
 
+## Deletes a folder and everything in it (a server's folder has its world in it).
 func _rmdir(d: String) -> void:
 	var da := DirAccess.open(d)
 	if da == null:
 		return
+	for sub in da.get_directories():
+		_rmdir(d.path_join(sub))
 	for f in da.get_files():
 		da.remove(f)
 	DirAccess.remove_absolute(d)

tests/test_net_shared.gd

@@ -0,0 +1,494 @@
+extends SceneTree
+## M2.3: the shared world. Two players on a dedicated server see the same
+## island change: a tree one of them fells (and its regrowth), pickups and
+## dropped items (first come, first served), building pieces (and walking
+## into them, for real and by cheating), doors, chests, fires, dismantling,
+## and the whole lot surviving a server restart.
+##
+## A real headless server, plus "Bob" (tests/net_world_bot.gd) as another
+## process with his own world, following this test's commands. This test is
+## "Alice" with the real world scene.
+## Run: godot --headless --path . --script res://tests/test_net_shared.gd
+
+const PORT := 24346
+const DIR := "user://test_net"
+const SRV := DIR + "/server5"
+const BOB := DIR + "/bob_cmds"
+const SEED := 777
+const Bot = preload("res://tests/net_world_bot.gd")
+
+var _fails := 0
+var _finished := false
+var _pids: Array[int] = []
+var Net: Node
+var WN: Node
+var A: Node
+var world: Node3D
+var player: CharacterBody3D
+var _cmd := 0
+var _server_pid := 0
+var _toasts: Array[String] = []
+
+func check(cond: bool, what: String) -> void:
+	print(("  ok   " if cond else "  FAIL ") + what)
+	if not cond:
+		_fails += 1
+
+func _initialize() -> void:
+	_run.call_deferred()
+
+func _run() -> void:
+	Engine.max_fps = 60
+	Net = root.get_node("Net")
+	WN = root.get_node("WorldNet")
+	A = root.get_node("Actions")
+	A.notify.connect(func(t): _toasts.append(t))
+	for d in [SRV, BOB]:
+		_rm_tree(d)
+	DirAccess.make_dir_recursive_absolute(BOB)
+	_start_server()
+	await _sleep(4.0)
+	await _body()
+	Net.stop()
+	for pid in _pids:
+		if OS.is_process_running(pid):
+			OS.kill(pid)
+	check(_finished, "test ran to the end (no script errors)")
+	_rm_tree(SRV)
+	_rm_tree(BOB)
+	print("RESULT: %s (%d failures)" % ["PASS" if _fails == 0 else "FAIL", _fails])
+	quit(1 if _fails > 0 else 0)
+
+func _start_server() -> void:
+	# --debug-regrow: things grow back in seconds instead of half an hour.
+	_server_pid = _spawn(["--server", "--port", str(PORT), "--config", SRV + "/server.json",
+		"--server-name", "Shared Test", "--seed", str(SEED), "--debug-regrow", "0.002"])
+
+func _body() -> void:
+	var me = load("res://scripts/net/identity.gd").open(DIR + "/a")
+	me.name = "Alice"
+	Net.identity = me
+	var r := await _join()
+	check(r == "", "Alice joins (%s)" % r)
+	if r != "":
+		return
+	await _load_world()
+	check(WN.received >= 1 and WN.world == world, "and gets the server's island")
+
+	print("Bob, with his own world")
+	_spawn(["--identity", DIR + "/bob", "--name", "Bob", "--address", "127.0.0.1:%d" % PORT, "--dir", BOB],
+		"res://tests/net_world_bot.gd")
+	var b0 := await _bob_result(0, 30.0)
+	check(bool(b0.get("ok", false)), "Bob joins and loads it too (%s)" % b0.get("why", "ok"))
+	if not bool(b0.get("ok", false)):
+		return
+
+	await _trees()
+	await _building()
+	await _containers_and_fires()
+	await _items_on_the_ground()
+	await _restart()
+	_finished = true
+
+# --- trees --------------------------------------------------------------------
+
+func _trees() -> void:
+	print("felling a tree")
+	var tree := _nearest(world.props.resource_nodes.values().filter(func(n): return n.kind == "tree" and not n.depleted))
+	var uid: String = tree.uid
+	var to_tree: Vector3 = (tree.global_position - player.global_position)
+	to_tree.y = 0.0
+	await Bot.walk(player, tree.global_position - to_tree.normalized() * 1.6, world)
+	player.inventory.set_slot(0, {"id": "stone_axe", "count": 1})
+	player.select(0)
+	var wood0: int = player.inventory.count("wood")
+	var hits := 0
+	var t := 0.0
+	while not tree.depleted and t < 20.0:
+		player.survival.stamina = 100.0
+		if A.harvest_hit(player, tree, tree.global_position + Vector3(0, 1.0, 0)):
+			hits += 1
+		await _sleep(0.25)
+		t += 0.25
+	check(tree.depleted, "Alice fells it in %d hits (her world shows it when the server says so)" % hits)
+	await _sleep(0.3)
+	check(player.inventory.count("wood") > wood0, "and the server gives her the wood (%d)" % (player.inventory.count("wood") - wood0))
+	var rep := await _bob({"do": "report", "uids": [uid]})
+	var bn: Variant = rep.nodes.get(uid)
+	check(bn != null and bool(bn.depleted), "Bob sees it fall too")
+
+	print("regrowth (sped up for the test)")
+	await _sleep(6.0)   # (trees take 4.8 s at this speed-up)
+	check(tree.depleted, "it doesn't grow back with Alice standing next to it")
+	var walk_from := Time.get_ticks_msec()
+	await Bot.walk(player, player.global_position + Vector3(14, 0, 0), world)
+	t = 0.0
+	while tree.depleted and t < 15.0:
+		await _sleep(0.2)
+		t += 0.2
+	check(not tree.depleted, "once she walks off, it grows back (%.1f s after she set off)" % ((Time.get_ticks_msec() - walk_from) / 1000.0))
+	rep = await _bob({"do": "report", "uids": [uid]})
+	bn = rep.nodes.get(uid)
+	check(bn != null and not bool(bn.depleted), "for Bob as well")
+
+# --- building -----------------------------------------------------------------
+
+var _wall: Node3D
+var _door: Node3D
+
+func _building() -> void:
+	print("building a wall")
+	var site: Vector3 = world.build.debug_find_site(player.global_position + Vector3(0, 0, 10), 3.0)
+	await Bot.walk(player, site + Vector3(-3.5, 0, 0), world)
+	_wall = await _place("wood_wall", site, 0.0)
+	check(_wall != null, "Alice puts up a wall (the server agrees and tells everyone)")
+	if _wall == null:
+		return
+	var rep := await _bob({"do": "report"})
+	var seen := _find(rep, "wood_wall")
+	check(not seen.is_empty() and _p(seen.pos).distance_to(_wall.global_position) < 0.01, "Bob has the same wall, in the same place")
+
+	print("Bob walks into it")
+	var n: Vector3 = _wall.global_basis.z.normalized()
+	var base := _wall.global_position
+	await _bob({"do": "walk", "to": _v(base + n * 2.5)})
+	var bump := await _bob({"do": "bump", "dir": _v(-n), "dist": 4.0})
+	check(float(bump.get("moved", 9.0)) < 2.3, "and it stops him (moved %.2f of 4 m)" % float(bump.get("moved", 9.0)))
+	var hop := await _bob({"do": "hop", "to": _v(base - n * 0.6 + Vector3(0, 0.05, 0))})
+	var hp: Vector3 = _p(hop.get("pos", [0, 0, 0]))
+	check(int(hop.get("corrected", 0)) >= 1 and (hp - base).dot(n) > 0.0,
+		"a game that steps him through anyway is refused by the server, and he's put back on his side")
+	await _dismantle()
+
+	print("a door")
+	var dsite: Vector3 = world.build.debug_find_site(site + Vector3(0, 0, 8), 2.0)
+	await Bot.walk(player, dsite + Vector3(-2.5, 0, 0), world)
+	_door = await _place("wood_door", dsite, 0.0)
+	check(_door != null, "Alice puts up a door")
+	if _door == null:
+		return
+	A.toggle_door(player, _door)
+	await _sleep(0.6)
+	check(_door.open, "she opens it")
+	rep = await _bob({"do": "report"})
+	seen = _find(rep, "wood_door")
+	check(not seen.is_empty() and bool(seen.get("open", false)), "and it's open for Bob")
+
+## Places `id` on the ground at `at` through Actions, the way the game does.
+func _place(id: String, at: Vector3, yaw: float) -> Node3D:
+	var def: Dictionary = root.get_node("ItemDB").get_item(id)
+	var xf := Transform3D(Basis(Vector3.UP, yaw), Vector3(at.x, world.terrain.sample_height(at.x, at.z), at.z))
+	if def.place.has("kind"):
+		var hit := {"position": xf.origin, "normal": Vector3.UP, "collider": world.terrain.get_node("TerrainBody")}
+		var res: Dictionary = world.build.placement(def, hit, yaw)
+		if not res.ok:
+			print("    (can't place %s: %s)" % [id, res.reason])
+			return null
+		xf = res.xf
+	player.inventory.set_slot(5, {"id": id, "count": 1})
+	var before: Array = WN.pieces.keys()
+	if not A.place(player, 5, xf, world):
+		print("    (Actions.place refused %s)" % id)
+		return null
+	check(player.inventory.get_slot(5) == null, "(%s taken from Alice's bag)" % id)
+	var t := 0.0
+	while t < 3.0:
+		for k in WN.pieces:
+			if not k in before and WN.pieces[k].item_id == id:
+				return WN.pieces[k]
+		await _sleep(0.05)
+		t += 0.05
+	return null
+
+# --- chests and fires ------------------------------------------------------------
+
+var _chest: Node3D
+var _fire: Node3D
+
+func _containers_and_fires() -> void:
+	print("a shared chest")
+	var site: Vector3 = world.build.debug_find_site(player.global_position + Vector3(6, 0, 0), 1.5)
+	await Bot.walk(player, site + Vector3(-2.0, 0, 0), world)
+	_chest = await _place("chest", site, 0.0)
+	check(_chest != null, "Alice places a chest")
+	if _chest == null:
+		return
+	player.inventory.set_slot(6, {"id": "wood", "count": 10})
+	A.transfer(player, player.inventory, 6, _chest.inventory, _chest)
+	await _sleep(0.5)
+	check(player.inventory.get_slot(6) == null and _chest.inventory.count("wood") == 10, "she puts 10 wood in")
+	var got := {"c": "waiting"}
+	WN.chest_click(_chest, 3, {"id": "stone", "count": 3}, false, func(c): got.c = c)
+	var t := 0.0
+	while got.c is String and t < 3.0:
+		await _sleep(0.05)
+		t += 0.05
+	check(got.c == null and _chest.inventory.get_slot(3) != null and _chest.inventory.get_slot(3).id == "stone",
+		"and drops 3 stone in slot 4 by hand (the server does the click and hands back an empty cursor)")
+	var nid: int = WN.nid(_chest)
+	await _bob({"do": "walk", "to": _v(site + Vector3(1.8, 0, 0))})
+	var rep := await _bob({"do": "report"})
+	var seen: Dictionary = rep.pieces.get(str(nid), {})
+	check(_count(seen.get("inv", []), "wood") == 10 and _count(seen.get("inv", []), "stone") == 3, "Bob sees what's in it")
+	var slot := -1
+	for i in range(_chest.inventory.size()):
+		var s = _chest.inventory.get_slot(i)
+		if s != null and s.id == "wood":
+			slot = i
+	var took := await _bob({"do": "chest_take", "nid": nid, "slot": slot})
+	check(_count(took.get("inv", []), "wood") == 10, "Bob takes the wood out (shift-click)")
+	await _sleep(0.3)
+	check(_chest.inventory.count("wood") == 0 and _chest.inventory.count("stone") == 3, "and it's gone from Alice's view of the chest")
+
+	print("a fire")
+	var fsite: Vector3 = world.build.debug_find_site(site + Vector3(0, 0, -5), 1.5)
+	await Bot.walk(player, fsite + Vector3(-2.0, 0, 0), world)
+	_fire = await _place("campfire", fsite, 0.0)
+	check(_fire != null, "Alice lights a campfire")
+	if _fire == null:
+		return
+	var f0: float = _fire.fuel
+	player.inventory.set_slot(7, {"id": "wood", "count": 2})
+	A.add_fuel(player, _fire)
+	await _sleep(0.5)
+	check(_fire.fuel > f0 + 30.0, "and feeds it a log (%.0f s -> %.0f s of fuel)" % [f0, _fire.fuel])
+	rep = await _bob({"do": "report"})
+	seen = rep.pieces.get(str(WN.nid(_fire)), {})
+	check(absf(float(seen.get("fuel", -100.0)) - _fire.fuel) < 5.0, "Bob's fire has the same fuel (%.0f s)" % float(seen.get("fuel", -1.0)))
+
+# --- things on the ground --------------------------------------------------------
+
+func _items_on_the_ground() -> void:
+	print("dropped items")
+	var at := player.global_position + Vector3(1.0, 0.1, 0)
+	world.drop_item("flint", 2, Transform3D(Basis(), at))
+	var t := 0.0
+	var key := ""
+	while key.is_empty() and t < 3.0:
+		for k in WN.dropped:
+			if WN.dropped[k].item_id == "flint":
+				key = "#%d" % k
+		await _sleep(0.05)
+		t += 0.05
+	check(not key.is_empty(), "Alice drops 2 flint: it's in the shared world")
+	var rep := await _bob({"do": "report"})
+	check(rep.dropped.any(func(d): return d.item == "flint" and int(d.count) == 2), "Bob sees it")
+	await _bob({"do": "walk", "to": _v(at + Vector3(1.0, 0, 0))})
+	var took := await _bob({"do": "take", "key": key})
+	check(_count(took.get("inv", []), "flint") == 2, "Bob picks it up")
+	await _sleep(0.3)
+	check(WN.dropped.is_empty() or not WN.dropped.has(int(key.substr(1))), "and it's gone for Alice")
+
+	print("first come, first served")
+	var pk := _nearest(world.props.pickups.values().filter(func(p): return not p.taken))
+	await Bot.walk(player, pk.global_position + Vector3(-1.0, 0, 0), world)
+	await _bob({"do": "walk", "to": _v(pk.global_position + Vector3(1.0, 0, 0))})
+	var id: String = pk.item_id
+	var a0: int = player.inventory.count(id)
+	_bob_send({"do": "take", "key": pk.uid})   # both reach for it at once
+	A.pickup(player, pk)
+	var br := await _bob_wait(_cmd)
+	await _sleep(0.4)
+	var a_got: int = player.inventory.count(id) - a0
+	var b_got: int = _count(br.get("inv", []), id) - (2 if id == "flint" else 0)
+	check(a_got + b_got == pk.amount and (a_got == 0 or b_got == 0),
+		"only one of them gets the %s (Alice %d, Bob %d)" % [id, a_got, b_got])
+
+	print("dying online")
+	player.inventory.load_data(Inventory.new(player.inventory.size()).to_data())
+	player.inventory.set_slot(0, {"id": "stone", "count": 7})
+	player.inventory.set_slot(1, {"id": "berries", "count": 4})
+	var died_at := player.global_position
+	world._on_player_died()
+	var grave: Node3D = null
+	var t2 := 0.0
+	while grave == null and t2 < 3.0:
+		for p in WN.pieces.values():
+			if p.item_id == "grave":
+				grave = p
+		await _sleep(0.05)
+		t2 += 0.05
+	check(grave != null and grave.global_position.distance_to(died_at) < 3.0 and player.inventory.count("stone") == 0,
+		"Alice dies: her things go into a grave in the shared world")
+	if grave == null:
+		return
+	var gnid: int = WN.nid(grave)
+	var rep2 := await _bob({"do": "report"})
+	var g: Dictionary = rep2.pieces.get(str(gnid), {})
+	check(_count(g.get("inv", []), "stone") == 7 and _count(g.get("inv", []), "berries") == 4, "Bob sees the grave, with what she had")
+	await Bot.walk(player, grave.global_position + Vector3(1.5, 0, 0), world)
+	for i in range(grave.inventory.size()):
+		if is_instance_valid(grave) and grave.inventory.get_slot(i) != null:
+			A.transfer(player, grave.inventory, i, player.inventory, grave)
+			await _sleep(0.15)
+	await _sleep(0.5)
+	check(player.inventory.count("stone") == 7 and player.inventory.count("berries") == 4, "she takes it all back")
+	check(not WN.pieces.has(gnid), "and the empty grave crumbles")
+	rep2 = await _bob({"do": "report"})
+	check(not rep2.pieces.has(str(gnid)), "for Bob too")
+
+# --- dismantling ---------------------------------------------------------------
+
+func _dismantle() -> void:
+	if _wall == null:
+		return
+	print("taking the wall down")
+	# (Straight after building it, while she's still beside it: a test walk
+	# back from somewhere else can cut through the door frame, and the
+	# server rightly sends her back.)
+	var nid: int = WN.nid(_wall)
+	var w0: int = player.inventory.count("wood_wall")
+	_toasts.clear()
+	var ok: bool = A.dismantle(player, _wall)
+	check(ok, "Alice dismantles the wall (%.1f m away%s)" % [player.global_position.distance_to(_wall.global_position),
+		"" if ok else ", refused: %s" % [_toasts]])
+	await _sleep(0.5)
+	check(not WN.pieces.has(nid) and player.inventory.count("wood_wall") == w0 + 1, "it's gone, and back in her bag")
+	var rep := await _bob({"do": "report"})
+	check(not rep.pieces.has(str(nid)), "gone for Bob too")
+
+# --- persistence -------------------------------------------------------------------
+
+func _restart() -> void:
+	print("the server restarts")
+	var expect := {}
+	for k in WN.pieces:
+		expect[k] = WN.pieces[k].item_id
+	var chest_nid: int = WN.nid(_chest) if _chest != null else -1
+	# Killed outright while everyone's still on (like Ctrl+C, which gives
+	# Godot no chance to save): the server saved within a few seconds of the
+	# last change anyway.
+	await _sleep(WN.SAVE_AFTER + 1.5)
+	check(FileAccess.file_exists(SRV + "/worlds/server-world/world.json"), "the server saved the island soon after the last change")
+	OS.kill(_server_pid)
+	_pids.erase(_server_pid)
+	await _bob({"do": "leave"})
+	world.queue_free()
+	await process_frame
+	Net.leave()
+	await _sleep(1.0)
+	_start_server()
+	await _sleep(4.0)
+	var r := await _join()
+	check(r == "", "Alice rejoins (%s)" % r)
+	if r != "":
+		return
+	await _load_world()
+	var same: bool = expect.size() == WN.pieces.size()
+	for k in expect:
+		same = same and WN.pieces.has(k) and WN.pieces[k].item_id == expect[k]
+	check(same, "everything built is still there, with the same ids (%d pieces)" % WN.pieces.size())
+	var c: Node3D = WN.pieces.get(chest_nid)
+	check(c != null and c.inventory.count("stone") == 3 and c.inventory.count("wood") == 0, "the chest still has the 3 stone")
+	var d: Node3D = null
+	for p in WN.pieces.values():
+		if p.item_id == "wood_door":
+			d = p
+	check(d != null and d.open, "and the door is still open")
+	world.queue_free()
+	await process_frame
+	Net.leave()
+
+# --- helpers --------------------------------------------------------------------
+
+func _load_world() -> void:
+	world = load("res://scenes/world.tscn").instantiate()
+	root.add_child(world)
+	for _i in range(8):
+		await physics_frame
+	player = world.player
+	player.set_physics_process(false)   # the test moves Alice
+	var t := 0.0
+	while WN.received < 1 and t < 10.0:
+		await _sleep(0.05)
+		t += 0.05
+
+func _nearest(nodes: Array) -> Node3D:
+	var best: Node3D = null
+	for n in nodes:
+		if best == null or n.global_position.distance_to(player.global_position) < best.global_position.distance_to(player.global_position):
+			best = n
+	return best
+
+func _find(rep: Dictionary, item: String) -> Dictionary:
+	for k in rep.get("pieces", {}):
+		if rep.pieces[k].item == item:
+			return rep.pieces[k]
+	return {}
+
+static func _count(inv: Array, id: String) -> int:
+	var n := 0
+	for s in inv:
+		if s != null and s.id == id:
+			n += int(s.count)
+	return n
+
+static func _v(p: Vector3) -> Array:
+	return [p.x, p.y, p.z]
+
+static func _p(a: Array) -> Vector3:
+	return Vector3(a[0], a[1], a[2])
+
+func _bob_send(cmd: Dictionary) -> void:
+	_cmd += 1
+	var f := FileAccess.open("%s/cmd_%d.json" % [BOB, _cmd], FileAccess.WRITE)
+	f.store_string(JSON.stringify(cmd))
+	f.close()
+
+func _bob(cmd: Dictionary) -> Dictionary:
+	_bob_send(cmd)
+	return await _bob_wait(_cmd)
+
+func _bob_wait(n: int) -> Dictionary:
+	return await _bob_result(n, 20.0)
+
+func _bob_result(n: int, limit: float) -> Dictionary:
+	var path := "%s/res_%d.json" % [BOB, n]
+	var t := 0.0
+	while not FileAccess.file_exists(path) and t < limit:
+		await _sleep(0.05)
+		t += 0.05
+	await _sleep(0.05)
+	var d: Variant = JSON.parse_string(FileAccess.get_file_as_string(path)) if FileAccess.file_exists(path) else null
+	return d if d is Dictionary else {"error": "Bob gave no answer to command %d" % n, "nodes": {}, "pieces": {}, "dropped": []}
+
+func _join() -> String:
+	var state := {"done": false, "reason": ""}
+	var ok := func(): state.done = true
+	var bad := func(why): state.done = true; state.reason = why
+	Net.joined.connect(ok)
+	Net.join_failed.connect(bad)
+	Net.join("127.0.0.1:%d" % PORT)
+	var t := 0.0
+	while not state.done and t < 25.0:
+		await _sleep(0.05)
+		t += 0.05
+	Net.joined.disconnect(ok)
+	Net.join_failed.disconnect(bad)
+	return state.reason if state.done else "test timed out"
+
+func _spawn(user_args: Array, script: String = "") -> int:
+	var args := PackedStringArray(["--headless", "--path", ProjectSettings.globalize_path("res://")])
+	if not script.is_empty():
+		args.append_array(["--script", script])
+	args.append("--")
+	for x in user_args:
+		args.append(str(x))
+	args.append_array(["--exit-with", str(OS.get_process_id())])
+	var pid := OS.create_process(OS.get_executable_path(), args)
+	_pids.append(pid)
+	return pid
+
+func _sleep(s: float) -> void:
+	await create_timer(s).timeout
+
+## Deletes a folder and everything in it.
+static func _rm_tree(d: String) -> void:
+	var da := DirAccess.open(d)
+	if da == null:
+		return
+	for sub in da.get_directories():
+		_rm_tree(d.path_join(sub))
+	for f in da.get_files():
+		da.remove(f)
+	DirAccess.remove_absolute(d)

tests/test_net_world.gd

@@ -252,10 +252,13 @@ func _result(path: String) -> Dictionary:
 func _sleep(s: float) -> void:
 	await create_timer(s).timeout
 
+## Deletes a folder and everything in it (a server's folder has its world in it).
 func _rmdir(d: String) -> void:
 	var da := DirAccess.open(d)
 	if da == null:
 		return
+	for sub in da.get_directories():
+		_rmdir(d.path_join(sub))
 	for f in da.get_files():
 		da.remove(f)
 	DirAccess.remove_absolute(d)