Add Steam networking capabilities (Round 2) #34
Description
Is your feature request related to a problem? Please describe (REQUIRED):
This is a new round of mappings required to continue multilayer development to utilise Steam's lobby and matchmaking features.
Describe the solution you'd like (REQUIRED):
There is a list of functions that need mapping, below.
Describe alternatives you've considered (REQUIRED):
We are implementing functionality that is not yet implemented from the Steam extension for Defold. I'm testing out the functionality as its implemented while the Defold team provides the mappngs.
Additional context (OPTIONAL):
Discussion is here: https://forum.defold.com/t/steam-multiplayer-api/80588/9
Ok now that I'm attempting to actually do it, looks like there are more functions and events that need mapping that I didn't realise when just reading the documentation. The next immediate issue I ran into is missing a mapping for "CreateLobby".
I "cheated" and use ChatGPT to assess the situation and make a complete list, but it's been extremely correct on this topic so far and this will likely save us many incremental back and forths as I try a bit, run into a roadblock, etc. etc.
Here is a comprehensive, focused list of Steamworks API functions and callbacks that should be mapped in Defold's Steam extension (extension-steam) in order to fully support Steam lobbies and friend joining via lobbies.
Each entry includes the original Steamworks symbol and a suggested Lua binding name consistent with the existing Defold Steam API.
🧱 Core API Functions to Bind
🟩 Lobby Management
| Steamworks C++ Function | Suggested Lua Binding | Description |
|---|---|---|
ISteamMatchmaking::CreateLobby(...) |
steam.matchmaking_create_lobby(lobby_type, max_players) |
Creates a lobby |
ISteamMatchmaking::JoinLobby(CSteamID) |
steam.matchmaking_join_lobby(lobby_id) |
Joins an existing lobby |
ISteamMatchmaking::LeaveLobby(CSteamID) |
steam.matchmaking_leave_lobby(lobby_id) |
Leaves the specified lobby |
🟦 Lobby Data Management
| Steamworks Function | Suggested Lua Binding | Description |
|---|---|---|
ISteamMatchmaking::SetLobbyData(...) |
steam.matchmaking_set_lobby_data(lobby_id, key, value) |
Sets key-value data for the lobby |
ISteamMatchmaking::GetLobbyData(...) |
steam.matchmaking_get_lobby_data(lobby_id, key) |
Retrieves a specific key from the lobby |
ISteamMatchmaking::GetLobbyDataCount(...) |
steam.matchmaking_get_lobby_data_count(lobby_id) |
(Optional) Gets the number of keys |
ISteamMatchmaking::GetLobbyDataByIndex(...) |
steam.matchmaking_get_lobby_data_by_index(lobby_id, index) |
(Optional) Enumerates keys |
🟨 Lobby Member Information
| Steamworks Function | Suggested Lua Binding | Description |
|---|---|---|
ISteamMatchmaking::GetNumLobbyMembers(CSteamID) |
steam.matchmaking_get_num_lobby_members(lobby_id) |
Returns member count |
ISteamMatchmaking::GetLobbyMemberByIndex(CSteamID, i) |
steam.matchmaking_get_lobby_member_by_index(lobby_id, index) |
Gets the SteamID of a member |
🔄 Lobby Messaging (Optional but Valuable)
| Steamworks Function | Suggested Lua Binding | Description |
|---|---|---|
ISteamMatchmaking::SendLobbyChatMsg(...) |
steam.matchmaking_send_lobby_chat_msg(lobby_id, message) |
Sends a chat message to all lobby members |
ISteamMatchmaking::GetLobbyChatEntry(...) |
steam.matchmaking_get_lobby_chat_entry(...) |
Retrieves received messages |
🔔 Required Callbacks to Map
These allow the Lua code to react to the result of lobby operations.
| Callback Struct | Event Constant | Description |
|---|---|---|
LobbyCreated_t |
steam.CALLBACK_LOBBY_CREATED |
Fired after CreateLobby() call completes |
LobbyEnter_t |
steam.CALLBACK_LOBBY_ENTERED |
Fired when local user successfully joins a lobby |
GameLobbyJoinRequested_t |
steam.CALLBACK_GAME_LOBBY_JOIN_REQUESTED |
Fired when a user clicks “Join Game” via Steam friends |
LobbyChatUpdate_t |
steam.CALLBACK_LOBBY_CHAT_UPDATE |
Fired when a player joins, leaves, or is kicked |
LobbyChatMsg_t |
steam.CALLBACK_LOBBY_CHAT_MSG |
Fired when a lobby message is received (if chat is used) |
📌 Optional but Useful Additions
These aren't strictly required, but they're common in games with lobby-based matchmaking:
| Function | Purpose |
|---|---|
ISteamMatchmaking::RequestLobbyList() |
Enables you to query lobbies from other players |
ISteamMatchmaking::AddRequestLobbyListStringFilter(...) |
Filters lobby results |
ISteamMatchmaking::GetLobbyByIndex(...) |
Lets you enumerate found lobbies |
ISteamMatchmaking::RequestLobbyData(CSteamID) |
Requests updated data for a lobby |
ISteamMatchmaking::SetLobbyJoinable(CSteamID, bool) |
Makes lobby joinable or not (host-only) |
Steam Documentation reference for matchmaking:
https://partner.steamgames.com/doc/api/ISteamMatchmaking