Part of the
multiplayer-state skill. The skill links here when your agent needs the detail.authority/main.gd
extends Node
## The match server. It runs headless and owns every rule.
const Game = preload("res://network/game.gd")
const PlayerArchetype = preload("res://authority/player_archetype.tres")
## How far a player may move in one burst after a network stall, in metres.
const BURST := Game.MAX_SPEED * 0.5
const REACH := 2.0 # how close a player must stand to collect a coin
var spawner: SummerNetworkSpawner
var world: SummerNetworkWorld
var seat_of := {} # session_id -> seat, held until the Session leaves
var allowance := {} # seat -> metres the player may still move
var refilled_at := {} # seat -> msec of the last allowance refill
var match_group: SummerNetworkStateGroup
var match_doc := {"coins": {"0": [10.0, 0.5, 0.0], "1": [-10.0, 0.5, 0.0], "2": [0.0, 0.5, 10.0]}, "scores": {}}
var mine_groups := {} # session_id -> private group
var wallets := {} # session_id -> coins this player holds
var receipts := {} # session_id -> {request id: result}
func _ready() -> void:
spawner = Game.build_network(self, PlayerArchetype)
world = $World
spawner.entity_spawned.connect(_on_player_spawned)
spawner.command_received.connect(_on_command)
world.session_left.connect(_on_session_left)
var initialized: SummerResult = await Summer.initialize().get_result_or_completed_signal()
if not initialized.ok:
push_error(initialized.message)
return
if not world.is_ready():
await world.binding_ready
if not spawner.is_network_ready():
await spawner.network_ready
match_group = spawner.create_state_group(Game.MATCH, &"match", Game.pack(match_doc))
print("COURTYARD_AUTHORITY_READY")
## A seat is a player's place in this World for their whole stay, across
## reconnects. Returns -1 when the World is full.
func _seat(session: SummerSession) -> int:
if seat_of.has(session.session_id):
return seat_of[session.session_id]
var taken := seat_of.values()
for seat in Game.MAX_PLAYERS:
if seat not in taken:
seat_of[session.session_id] = seat
return seat
return -1
## The Spawner spawns one player entity per joined player, once that player's
## network is ready (and again after a reconnect). Its owner becomes the only
## writer of the pose; the group ends with the entity.
func _on_player_spawned(entity: SummerNetworkEntity) -> void:
var seat := _seat(entity.session)
if seat < 0:
push_warning("no free seat")
return
allowance[seat] = BURST
refilled_at[seat] = Time.get_ticks_msec()
var group := spawner.create_state_group(Game.MOTION, Game.motion_key(seat), Game.spawn_pose(seat, entity.entity_id), entity.session, entity)
group.set_acceptance_policy(_accept_motion.bind(seat))
print("COURTYARD_PLAYER_SPAWNED seat=%d entity=%d" % [seat, entity.entity_id])
## Runs on every pose an owner submits. True accepts it unchanged; false
## refuses it, and the owner snaps back to the last accepted pose.
func _accept_motion(candidate: Dictionary, current: Dictionary, seat: int) -> bool:
if candidate.entity != current.entity:
return false # a player can move, never become someone else
var position: Vector3 = candidate.position
if not Game.in_bounds(position) or not is_finite(candidate.yaw):
return false
# A distance allowance refilled at MAX_SPEED: bursts after a stall pass,
# speed hacks and teleports do not.
var now := Time.get_ticks_msec()
var budget := minf(float(allowance[seat]) + Game.MAX_SPEED * (now - int(refilled_at[seat])) / 1000.0, BURST)
refilled_at[seat] = now
var distance := position.distance_to(current.position)
if distance > budget:
allowance[seat] = budget
return false
allowance[seat] = budget - distance
return true
## Moves a player on purpose (respawn, portal). The owner snaps to it.
func teleport(seat: int, position: Vector3) -> void:
var group := spawner.get_state_group(Game.MOTION, Game.motion_key(seat))
if group != null and group.active:
var pose := group.get_state()
pose.position = position
allowance[seat] = BURST
group.reset(pose)
func _on_command(request: SummerNetworkCommandRequest) -> void:
var command := Game.unpack(request.payload)
var session := request.get_session()
var rid := str(command.get("rid", ""))
# A retry of a request already answered gets the same answer, applied once.
var answered: Dictionary = receipts.get(session.session_id, {})
if rid != "" and answered.has(rid):
request.accept({}, Game.pack(answered[rid]))
return
match str(command.get("c", "")):
"join":
_join(request)
"collect":
_collect(request, rid, str(command.get("coin", "")))
_:
request.refuse(&"unknown_command")
## A client sends "join" once its network is ready: set up what the player
## owns besides their body.
func _join(request: SummerNetworkCommandRequest) -> void:
var session := request.get_session()
var seat := _seat(session)
if seat < 0:
request.refuse(&"match_full")
return
if not mine_groups.has(session.session_id):
wallets[session.session_id] = 0
# Private state: only this Session receives it, only the authority writes it.
mine_groups[session.session_id] = spawner.create_state_group(Game.MINE, StringName("mine%d" % seat), Game.pack({"coins": 0}), null, null, session)
request.accept({}, Game.pack({"seat": seat}))
print("COURTYARD_PLAYER_JOINED seat=%d" % seat)
## Checks everything before changing anything, then changes state only
## through the groups so every client, late joiners included, agrees.
func _collect(request: SummerNetworkCommandRequest, rid: String, coin: String) -> void:
var session := request.get_session()
if rid == "":
request.refuse(&"missing_request_id")
return
if not mine_groups.has(session.session_id):
request.refuse(&"not_joined")
return
if not match_doc.coins.has(coin):
request.refuse(&"coin_gone")
return
# The player's latest accepted pose, never a position from the payload.
var body := spawner.get_state_group(Game.MOTION, Game.motion_key(seat_of[session.session_id]))
if body == null or not body.active:
request.refuse(&"not_spawned")
return
var at: Array = match_doc.coins[coin]
if (body.get_state().position as Vector3).distance_to(Vector3(at[0], at[1], at[2])) > REACH:
request.refuse(&"too_far")
return
match_doc.coins.erase(coin)
var name := session.player.display_name
match_doc.scores[name] = int(match_doc.scores.get(name, 0)) + 1
match_group.reset(Game.pack(match_doc))
wallets[session.session_id] += 1
(mine_groups[session.session_id] as SummerNetworkStateGroup).reset(Game.pack({"coins": wallets[session.session_id]}))
spawner.publish_event_by_policy(Game.FX, {"position": Vector3(at[0], at[1], at[2])})
var result := {"coin": coin, "coins": wallets[session.session_id]}
var answered: Dictionary = receipts.get(session.session_id, {})
answered[rid] = result
receipts[session.session_id] = answered
request.accept({}, Game.pack(result))
## The Session ended for good: free the seat and everything the player had.
func _on_session_left(session: SummerSession, reason: String) -> void:
var seat: int = seat_of.get(session.session_id, -1)
seat_of.erase(session.session_id)
var mine: SummerNetworkStateGroup = mine_groups.get(session.session_id)
if mine != null and mine.active:
mine.retire()
mine_groups.erase(session.session_id)
wallets.erase(session.session_id)
receipts.erase(session.session_id)
print("COURTYARD_PLAYER_LEFT seat=%d reason=%s" % [seat, reason])
client/bot.gd
extends Node
## Test bot for Local Play, enabled with `-- --bot={client}`. It presses the
## real input actions. Bot 1 walks to the first coin and collects it; every
## bot prints what it sees, for the test run to check.
const COIN := "0"
var number := 0
var main: Node
var elapsed := 0.0
var step := 0
func _process(delta: float) -> void:
elapsed += delta
var me := _own_player()
if me == null:
return
if number == 1 and step == 0:
var at: Array = main.match_doc.get("coins", {}).get(COIN, [])
if at.is_empty():
return
var to_coin := Vector2(at[0] - me.global_position.x, at[2] - me.global_position.z)
if to_coin.length() > 0.5:
_steer(to_coin.normalized())
return
_steer(Vector2.ZERO)
step = 1
print("BOT_MOVED %s" % me.global_position)
var collected: Dictionary = await main.collect(COIN)
print("BOT_COLLECT %s" % JSON.stringify(collected))
if elapsed > 6.0 and step < 2:
step = 2
for node in main.get_node("Entities").get_children():
if node != me:
print("BOT_SAW %s" % node.global_position)
print("BOT_SCORES %s" % JSON.stringify(main.match_doc.get("scores", {})))
func _own_player() -> Node3D:
for node in main.get_node("Entities").get_children():
if node.get_script() == preload("res://client/player_owner.gd"):
return node
return null
func _steer(direction: Vector2) -> void:
for action in [&"ui_left", &"ui_right", &"ui_up", &"ui_down"]:
Input.action_release(action)
if direction.x > 0.0: Input.action_press(&"ui_right", direction.x)
if direction.x < 0.0: Input.action_press(&"ui_left", -direction.x)
if direction.y > 0.0: Input.action_press(&"ui_down", direction.y)
if direction.y < 0.0: Input.action_press(&"ui_up", -direction.y)
client/main.gd
extends Node
## What each player runs: joins the match and shows every player.
const Game = preload("res://network/game.gd")
const PlayerArchetype = preload("res://client/player_archetype.tres")
var spawner: SummerNetworkSpawner
var waiting := {} # entity id -> pose group that arrived before its entity
var match_doc := {} # what the authority published for everyone
var mine := {} # what the authority published for this player only
func _ready() -> void:
spawner = Game.build_network(self, PlayerArchetype)
# Connect before joining, or the first values arrive unseen.
spawner.state_group_created.connect(_on_group_created)
spawner.entity_spawned.connect(_on_entity_spawned)
spawner.event_received.connect(_on_event)
var initialized: SummerResult = await Summer.initialize().get_result_or_completed_signal()
if not initialized.ok:
push_error(initialized.message)
return
var join := Summer.client.join(SummerJoinTarget.queue(Game.QUEUE))
# Hosted matchmaking may ask the player to accept a match.
join.acceptance_required.connect(func(proposal: SummerMatchmakingProposal) -> void: proposal.accept())
var joined: SummerResult = await join.get_result_or_completed_signal()
if not joined.ok:
push_error("join failed: %s %s" % [joined.code, joined.message])
return
if not spawner.is_network_ready():
await spawner.network_ready
var entered := await command({"c": "join"})
if not entered.ok:
push_error("could not enter the match: %s" % entered.error)
return
print("COURTYARD_CLIENT_JOINED")
# Local Play test bot: `-- --bot={client}` (see multiplayer-testing).
for arg in OS.get_cmdline_user_args():
if arg.begins_with("--bot="):
var bot := preload("res://client/bot.gd").new()
bot.number = int(arg.trim_prefix("--bot="))
bot.main = self
add_child(bot)
## Sends one Command and waits for the authority's answer.
func command(payload: Dictionary) -> Dictionary:
var admission := spawner.enqueue_command(Game.CMD, Game.pack(payload))
if not admission.is_enqueued():
return {"ok": false, "error": String(admission.get_code())}
var handle := admission.get_handle()
if not handle.is_terminal():
await handle.completed
if handle.get_outcome() == SummerNetworkCommandHandle.OUTCOME_ACCEPTED:
return {"ok": true, "error": "", "result": Game.unpack(handle.get_result())}
return {"ok": false, "error": String(handle.get_reason())}
func _on_group_created(group: SummerNetworkStateGroup) -> void:
match group.get_stream_id():
Game.MOTION:
_attach_pose(group, int(group.get_state().entity))
Game.MATCH, Game.MINE:
# The baseline is already installed when this fires; later
# changes arrive through state_installed.
_on_document(group, group.get_state())
group.state_installed.connect(func(state: Dictionary, _revision: int, _reset: bool) -> void: _on_document(group, state))
## The pose group and the player's entity can arrive in either order.
func _attach_pose(group: SummerNetworkStateGroup, entity_id: int) -> void:
var entity := spawner.get_entity(entity_id)
if entity == null or entity.root == null:
waiting[entity_id] = group
return
entity.root.bind(group)
func _on_entity_spawned(entity: SummerNetworkEntity) -> void:
if waiting.has(entity.entity_id):
_attach_pose(waiting[entity.entity_id], entity.entity_id)
waiting.erase(entity.entity_id)
func _on_document(group: SummerNetworkStateGroup, state: Dictionary) -> void:
if group.get_stream_id() == Game.MATCH:
match_doc = Game.unpack(state)
else:
mine = Game.unpack(state)
func _on_event(event: SummerNetworkEvent) -> void:
if event.stream_id == Game.FX:
print("COURTYARD_SPARKLE at %s" % event.payload.position)
## Asks the authority for a coin. The request id makes a retry safe.
func collect(coin: String) -> Dictionary:
return await command({"c": "collect", "coin": coin, "rid": "collect-%s-%d" % [coin, Time.get_ticks_usec()]})
export_presets.cfg
[preset.0]
name="summer.games"
platform="summer.games"
runnable=false
dedicated_server=false
custom_features="summer_client"
export_filter="all_resources"
include_filter=""
exclude_filter=""
export_path=""
encrypt_pck=false
encrypt_directory=false
script_export_mode=2
[preset.0.options]
platforms/ios=true
platforms/macos=true
platforms/windows=false
[preset.1]
name="Courtyard Authority"
platform="Linux"
runnable=false
dedicated_server=true
custom_features="summer_authority"
export_filter="all_resources"
include_filter=""
exclude_filter="client/*"
export_path=""
encrypt_pck=false
encrypt_directory=false
script_export_mode=2
[preset.1.options]
binary_format/architecture="x86_64"
network/composition.tres
[gd_resource type="SummerNetworkComposition" load_steps=22 format=3]
[sub_resource type="SummerNetworkField" id="MotionPosition"]
field_name = &"position"
type = 9
[sub_resource type="SummerNetworkField" id="MotionYaw"]
field_name = &"yaw"
type = 2
[sub_resource type="SummerNetworkField" id="MotionEntity"]
field_name = &"entity"
type = 1
[sub_resource type="SummerNetworkSchema" id="MotionSchema"]
schema_id = &"courtyard.motion.v1"
state_fields = Array[SummerNetworkField]([SubResource("MotionEntity"), SubResource("MotionPosition"), SubResource("MotionYaw")])
[sub_resource type="SummerWorldAudience" id="Everyone"]
max_expansion = 8
[sub_resource type="SummerNetworkStateStream" id="Motion"]
stream_id = &"courtyard.motion"
writer_policy = 1
skip_writer_echo = true
state_schema = SubResource("MotionSchema")
audience_policy = SubResource("Everyone")
max_audience_count = 8
max_keys = 8
max_state_bytes = 1024
max_total_bytes = 8192
[sub_resource type="SummerNetworkField" id="CommandBytes"]
field_name = &"b"
type = 20
[sub_resource type="SummerNetworkSchema" id="CommandSchema"]
schema_id = &"courtyard.cmd.v1"
state_fields = Array[SummerNetworkField]([SubResource("CommandBytes")])
[sub_resource type="SummerNetworkField" id="ResultBytes"]
field_name = &"b"
type = 20
[sub_resource type="SummerNetworkSchema" id="ResultSchema"]
schema_id = &"courtyard.cmd.result.v1"
state_fields = Array[SummerNetworkField]([SubResource("ResultBytes")])
[sub_resource type="SummerNetworkOccurrenceStream" id="Commands"]
stream_id = &"courtyard.cmd"
command_scope = 2
command_tick_dispatch = true
command_timeout_msec = 8000
payload_schema = SubResource("CommandSchema")
result_schema = SubResource("ResultSchema")
[sub_resource type="SummerNetworkField" id="MatchBytes"]
field_name = &"b"
type = 20
[sub_resource type="SummerNetworkSchema" id="MatchSchema"]
schema_id = &"courtyard.match.v1"
state_fields = Array[SummerNetworkField]([SubResource("MatchBytes")])
[sub_resource type="SummerWorldAudience" id="MatchAudience"]
max_expansion = 8
[sub_resource type="SummerNetworkStateStream" id="Match"]
stream_id = &"courtyard.match"
state_schema = SubResource("MatchSchema")
audience_policy = SubResource("MatchAudience")
max_audience_count = 8
max_keys = 1
max_state_bytes = 4096
max_total_bytes = 4096
[sub_resource type="SummerNetworkField" id="MineBytes"]
field_name = &"b"
type = 20
[sub_resource type="SummerNetworkSchema" id="MineSchema"]
schema_id = &"courtyard.mine.v1"
state_fields = Array[SummerNetworkField]([SubResource("MineBytes")])
[sub_resource type="SummerTargetSessionAudience" id="OnlyThatPlayer"]
max_expansion = 1
[sub_resource type="SummerNetworkStateStream" id="Mine"]
stream_id = &"courtyard.mine"
state_schema = SubResource("MineSchema")
audience_policy = SubResource("OnlyThatPlayer")
max_audience_count = 1
max_keys = 8
max_state_bytes = 1024
max_total_bytes = 8192
[sub_resource type="SummerNetworkField" id="FxPosition"]
field_name = &"position"
type = 9
[sub_resource type="SummerNetworkSchema" id="FxSchema"]
schema_id = &"courtyard.fx.v1"
state_fields = Array[SummerNetworkField]([SubResource("FxPosition")])
[sub_resource type="SummerWorldAudience" id="FxAudience"]
max_expansion = 8
[sub_resource type="SummerNetworkOccurrenceStream" id="Fx"]
stream_id = &"courtyard.fx"
kind = 2
command_scope = 0
event_scope = 2
event_delivery = 2
transient_ttl_ticks = 30
max_outcome_history = 0
command_timeout_msec = 0
audience_policy = SubResource("FxAudience")
max_audience_count = 8
payload_schema = SubResource("FxSchema")
[resource]
network_version = "1.0.0"
state_streams = Array[SummerNetworkStateStream]([SubResource("Motion"), SubResource("Match"), SubResource("Mine")])
occurrence_streams = Array[SummerNetworkOccurrenceStream]([SubResource("Commands"), SubResource("Fx")])
network/game.gd
extends RefCounted
## Shared by the client and the authority: ids, streams and shared rules.
const QUEUE := &"courtyard"
const MOTION := &"courtyard.motion"
const CMD := &"courtyard.cmd"
const MATCH := &"courtyard.match" # one document every player sees
const MINE := &"courtyard.mine" # one private document per player
const FX := &"courtyard.fx" # one-off effects, never stored
const MAX_PLAYERS := 8
const COMPOSITION := preload("res://network/composition.tres")
## The authority's sanity bound on movement, in metres per second. Keep it
## above the fastest legitimate speed (walking, jumping, falling).
const MAX_SPEED := 15.0
const ARENA_RADIUS := 40.0
## Adds the World, an Entities root and the Spawner under `parent`. Both sides
## pass their own player archetype; the composition is the same file.
static func build_network(parent: Node, player: SummerEntityArchetype) -> SummerNetworkSpawner:
var world := SummerNetworkWorld.new()
world.name = "World"
parent.add_child(world)
var entities := Node3D.new()
entities.name = "Entities"
parent.add_child(entities)
var spawner := SummerNetworkSpawner.new()
spawner.name = "Spawner"
spawner.network_world_path = NodePath("../World")
spawner.entities_root_path = NodePath("../Entities")
spawner.archetypes = [player]
spawner.player_archetype = &"player" # one entity per joined player
spawner.network_composition = COMPOSITION
parent.add_child(spawner)
return spawner
## Pose groups are keyed by seat, so a stream needs at most MAX_PLAYERS keys.
static func motion_key(seat: int) -> StringName:
return StringName("p%d" % seat)
## Seats spawn on a circle. `entity` ties the pose to the player's entity.
static func spawn_pose(seat: int, entity_id: int) -> Dictionary:
var angle := TAU * float(seat) / MAX_PLAYERS
return {"entity": entity_id, "position": Vector3(cos(angle) * 4.0, 1.0, sin(angle) * 4.0), "yaw": 0.0}
static func in_bounds(position: Vector3) -> bool:
return position.is_finite() and Vector2(position.x, position.z).length() <= ARENA_RADIUS \
and position.y > -10.0 and position.y < 30.0
## Commands and results travel as JSON bytes: a network String holds at most
## 256 bytes.
static func pack(document: Dictionary) -> Dictionary:
return {"b": JSON.stringify(document).to_utf8_buffer()}
static func unpack(fields: Dictionary) -> Dictionary:
var parsed: Variant = JSON.parse_string((fields.get("b", PackedByteArray()) as PackedByteArray).get_string_from_utf8())
return parsed if parsed is Dictionary else {}
Source:
library/skills/multiplayer-state/files.md, rendered from summer-engine@4.3.0 on npm.
