Add collaborative surface drawing

network/network_player_list_service.gd

@@ -11,6 +11,7 @@ var _known: KnownPlayerStore
 var _spawn: PlayerSpawnService
 var _chat: NetworkChatService
 var _mail: NetworkMailService
+var _surface_drawing: NetworkSurfaceDrawingService
 var _revision := 0
 var _host_block_pairs: Dictionary[String, bool] = {}
 var _peer_fingerprints: Dictionary[int, String] = {}
@@ -96,6 +97,42 @@ func get_bans() -> Array[Dictionary]:
 	return _bans.get_bans(_session.get_host_identity_fingerprint()) if _session.is_host() else []
 
 
+func set_surface_drawing_service(
+	service: NetworkSurfaceDrawingService,
+) -> void:
+	_surface_drawing = service
+	if (
+		_surface_drawing != null
+		and not _surface_drawing.session_artwork_changed.is_connected(
+			_on_session_artwork_changed
+		)
+	):
+		_surface_drawing.session_artwork_changed.connect(
+			_on_session_artwork_changed
+		)
+	_changed()
+
+
+func get_session_artwork_counts() -> Vector2i:
+	if _surface_drawing == null:
+		return Vector2i.ZERO
+	return Vector2i(
+		_surface_drawing.get_canvas_count(),
+		_surface_drawing.get_painted_cell_count(),
+	)
+
+
+func reset_session_artwork() -> bool:
+	if not _session.is_host() or _surface_drawing == null:
+		return false
+	var ok: bool = _surface_drawing.clear_session_artwork()
+	moderation_finished.emit(
+		ok,
+		"Session artwork cleared." if ok else "Session artwork could not be cleared.",
+	)
+	return ok
+
+
 func set_muted(fingerprint: String, display_name: String, value: bool) -> bool:
 	if fingerprint == _session.get_local_identity_fingerprint():
 		return false
@@ -269,3 +306,10 @@ func _entry_before(a: PlayerListEntry, b: PlayerListEntry) -> bool:
 func _changed() -> void:
 	_revision += 1
 	entries_changed.emit()
+
+
+func _on_session_artwork_changed(
+	_canvas_count: int,
+	_painted_cell_count: int,
+) -> void:
+	_changed()

network/network_protocol.gd

@@ -10,7 +10,7 @@ const MAX_PUBLIC_KEY_LENGTH: int = 8192
 const MAX_SIGNATURE_LENGTH: int = 2048
 # ENet channels: 0 reliable lifecycle, 1 movement input, 2 movement
 # snapshots, 3 fishing input, 4 fishing snapshots, 5 reliable sales,
-# 6 reliable shop transactions, 7 reliable item/equipment/showcase lifecycle,
+# 6 reliable shop transactions, 7 reliable item/equipment/showcase/drawing,
 # 8 reliable ordered session chat, 9 reliable private session mail.
 const SALE_RELIABLE_CHANNEL: int = 5
 const SHOP_RELIABLE_CHANNEL: int = 6
@@ -18,6 +18,7 @@ const ITEM_RELIABLE_CHANNEL: int = 7
 const CHAT_RELIABLE_CHANNEL: int = 8
 const MAIL_RELIABLE_CHANNEL: int = 9
 const ENET_CHANNEL_COUNT: int = 10
+const SURFACE_DRAWING_CAPABILITY: String = "surface_drawing_v1"
 
 enum RejectionCode {
 	NONE,
@@ -83,7 +84,9 @@ static func make_client_hello(
 		"local_profile_id": profile_id,
 		"display_name": display_name,
 		"client_nonce": client_nonce,
-		"capability_flags": PackedStringArray(),
+		"capability_flags": PackedStringArray([
+			SURFACE_DRAWING_CAPABILITY,
+		]),
 		"cosmetic_snapshot": cosmetic_snapshot,
 		"identity_fingerprint": identity_fingerprint,
 		"identity_signature": identity_signature,
@@ -122,6 +125,16 @@ static func validate_client_hello(data: Variant) -> String:
 		TYPE_ARRAY,
 	]:
 		return "Capabilities are invalid."
+	var capabilities: Variant = payload["capability_flags"]
+	if capabilities.size() > 32:
+		return "Capabilities are invalid."
+	for capability: Variant in capabilities:
+		if (
+			typeof(capability) not in [TYPE_STRING, TYPE_STRING_NAME]
+			or str(capability).is_empty()
+			or str(capability).length() > 64
+		):
+			return "Capabilities are invalid."
 	if typeof(payload["cosmetic_snapshot"]) != TYPE_DICTIONARY:
 		return "Cosmetic snapshot is invalid."
 	if (
@@ -188,6 +201,7 @@ static func make_server_hello(
 			"item_use_v1",
 			"equipment_v1",
 			"fish_showcase_v1",
+			SURFACE_DRAWING_CAPABILITY,
 			"chat_v1",
 			"mail_v1",
 			"profile_v1",

network/network_session.gd

@@ -168,6 +168,7 @@ func start_private_host(port: int = DEFAULT_PORT) -> bool:
 		NetworkProtocol.PROTOCOL_VERSION,
 		_player_identity.fingerprint,
 		_player_identity.public_pem,
+		PackedStringArray([NetworkProtocol.SURFACE_DRAWING_CAPABILITY]),
 	)
 	_registry.update_appearance(1, _local_appearance_snapshot)
 	var host_profile_hello := NetworkProtocol.make_client_hello(
@@ -361,6 +362,7 @@ func supports_server_capability(capability: StringName) -> bool:
 		return str(capability) in PackedStringArray([
 			"movement_v1", "fishing_v1", "sale_v1", "shop_v1",
 			"item_use_v1", "equipment_v1", "fish_showcase_v1",
+			NetworkProtocol.SURFACE_DRAWING_CAPABILITY,
 			"chat_v1",
 			"mail_v1",
 			"profile_v1",
@@ -373,6 +375,14 @@ func get_peer_record(peer_id: int) -> PeerRegistry.PeerRecord:
 	return _registry.get_peer(peer_id)
 
 
+func peer_supports_capability(
+	peer_id: int,
+	capability: StringName,
+) -> bool:
+	var record: PeerRegistry.PeerRecord = _registry.get_peer(peer_id)
+	return record != null and str(capability) in record.capability_flags
+
+
 func get_authenticated_peer_ids() -> Array[int]:
 	return _registry.get_peer_ids()
 
@@ -931,6 +941,7 @@ func submit_client_hello(data: Dictionary) -> void:
 		NetworkProtocol.PROTOCOL_VERSION,
 		identity["fingerprint"],
 		identity["public_key"],
+		_sanitized_capabilities(data.get("capability_flags", [])),
 	):
 		_reject_peer(
 			sender_id,
@@ -1062,6 +1073,7 @@ func receive_server_hello(data: Dictionary) -> void:
 		NetworkProtocol.PROTOCOL_VERSION,
 		_player_identity.fingerprint,
 		_player_identity.public_pem,
+		PackedStringArray([NetworkProtocol.SURFACE_DRAWING_CAPABILITY]),
 	)
 	_registry.update_appearance(local_peer_id, _local_appearance_snapshot)
 	var local_record := _registry.get_peer(local_peer_id)
@@ -1143,6 +1155,7 @@ func _apply_spawn_entry(entry: Dictionary) -> void:
 			NetworkProtocol.PROTOCOL_VERSION,
 			str(entry.get("identity_fingerprint", "")),
 			str(entry.get("identity_public_key", "")),
+			_sanitized_capabilities(entry.get("capability_flags", [])),
 		)
 		var added_record := _registry.get_peer(peer_id)
 		if added_record != null and added_record.identity_authenticated:
@@ -1218,9 +1231,28 @@ func _make_spawn_entry(
 			record.profile_authorization.duplicate(true)
 			if record != null else {}
 		),
+		"capability_flags": (
+			record.capability_flags.duplicate()
+			if record != null else PackedStringArray()
+		),
 	}
 
 
+func _sanitized_capabilities(value: Variant) -> PackedStringArray:
+	var result := PackedStringArray()
+	if typeof(value) not in [TYPE_ARRAY, TYPE_PACKED_STRING_ARRAY]:
+		return result
+	for capability: Variant in value:
+		if (
+			typeof(capability) in [TYPE_STRING, TYPE_STRING_NAME]
+			and not str(capability).is_empty()
+			and str(capability).length() <= 64
+			and str(capability) not in result
+		):
+			result.append(str(capability))
+	return result
+
+
 func _verify_spawn_identity(entry: Dictionary) -> bool:
 	var fingerprint := str(entry.get("identity_fingerprint", ""))
 	var public_pem := NetworkIdentityCrypto.normalize_public_pem(

network/network_surface_drawing_service.gd.uid

@@ -0,0 +1 @@
+uid://bkiepgu8j5r6t

network/peer_registry.gd

@@ -16,6 +16,7 @@ class PeerRecord:
 	var identity_public_key: String = ""
 	var identity_authenticated: bool = false
 	var profile_authorization: Dictionary = {}
+	var capability_flags: PackedStringArray = PackedStringArray()
 
 
 var _records: Dictionary[int, PeerRecord] = {}
@@ -28,6 +29,7 @@ func add_peer(
 	protocol_version: int,
 	identity_fingerprint: String = "",
 	identity_public_key: String = "",
+	capability_flags: PackedStringArray = PackedStringArray(),
 ) -> bool:
 	if (
 		peer_id <= 0
@@ -49,6 +51,7 @@ func add_peer(
 	record.identity_authenticated = NetworkIdentityCrypto.valid_fingerprint(
 		identity_fingerprint
 	)
+	record.capability_flags = capability_flags.duplicate()
 	_records[peer_id] = record
 	return true