plasma.steam

Steam platform backend for PlasmaEngine's Platform Services, published as plasma.steam.

It implements plPlatformBackend on the Steamworks SDK: identity, achievements, stats, leaderboards, friends, rich presence, lobbies, lobby-based matchmaking, invites and launch joins, DLC entitlements, the Steam overlay, peer-to-peer datagrams over Steam Datagram Relay, and Steam Cloud saves through the save system's plSaveGameCloudProvider seam. Voice is not provided (the hub answers Unsupported).

Layout

Package.plPackage        the manifest - identity, compatibility, components
Steam.plPluginBundle     what plugin discovery reads
plasma.steam.workspace.cs
Configs/
  PlasmaPackageSdk.pb.cs   build rules against an installed engine SDK (stamped from the engine)
  PlasmaPackageSteam.pb.cs locates the Steamworks SDK through STEAM_SDK_PATH
Source/SteamPlugin/      runtime -> plSteamPlugin
  SteamPlatformBackend.h/.cpp   the backend object, lifecycle, callback registry, id helpers
  Capabilities/                 one file per provider interface
Branding/                icon, banner and the script that renders them

Runtime only: no editor plugin. The backend is never created in tool processes (editor, engine process, command-line tools); those keep the local backend.

What you still need

The Steamworks SDK is not redistributed. Download it from partner.steamgames.com and:

• To build: set STEAM_SDK_PATH to the SDK root - the directory containing public/steam/steam_api.h and redistributable_bin/win64/steam_api64.lib (the sdk folder inside the zip; the folder above it is accepted too).
• To run: copy redistributable_bin/win64/steam_api64.dll next to the game executable. Without it plSteamPlugin.dll fails to load and the hub falls back to the local backend.

Configuration

RuntimeConfigs/PlatformServices.ddl names the backend and its app id:

BackendOrder { "steam", "local" }
BackendSettings
{
  steam { AppId = 480 }
}

With AppId set the backend calls SteamAPI_RestartAppIfNecessary; a build not started through the Steam client is relaunched by Steam and Initialize fails so the hub falls back while this process exits. Development builds write steam_appid.txt beside the executable when it is missing, which is what lets a build started from the editor or a debugger talk to a running Steam client. Shipping builds never write it.

Per-backend ids in PlatformDefinitions.ddl use the backend name steam: achievement and stat ids are the API names from the Steamworks admin, leaderboard ids are leaderboard names, DLC ids are the decimal DLC app ids.

Behaviour notes

• Ids: users are steam:<SteamID64>, lobbies are the decimal lobby CSteamID.
• Achievements and stats wait for UserStatsReceived_t; requests made before that are queued and run when it arrives. On SDKs that removed RequestCurrentStats (1.61+) the stats are already loaded by init; the build detects which SDK it has (PL_STEAM_HAS_REQUEST_CURRENT_STATS).
• Matchmaking is a loop: search with the request's filters, join the first lobby with room, and after three empty rounds host a public lobby with the request's attributes and report Found for it.
• Transport uses ISteamNetworkingMessages. Channels 0..7 are polled; a session with a peer is accepted while Listen() is active and refused otherwise.
• Cloud saves are one file per slot, sav_<project>_<profile>_<slot>.plsave, with a small header in front of the envelope carrying revision, parent revision and the deleted flag. Publish reads the remote header first and answers Conflict when the revision is not the expected one; Steam has no server-side compare, so the check is client-side.
• Lobby member attributes are read for the keys the lobby itself carries, since Steam cannot enumerate member data keys.

Building

Requires an engine SDK - a built engine checkout - named by PLASMA_SDK_ROOT, and the Steamworks SDK named by STEAM_SDK_PATH:

PLASMA_SDK_ROOT=/path/to/engine STEAM_SDK_PATH=/path/to/steamworks/sdk plasmabuild build SteamPlugin

Output lands in Bin/Windows_x64_Development/.

Artwork

Branding/make_art.py composes the icon (512x512) and banner (1100x512) from the official Steam marks in Branding/source/ (renders of Valve's Steam_icon_logo.svg and Steam_2016_logo_black.svg), white on charcoal, with a pure-Python PNG codec. Steam and the Steam logo are trademarks of Valve Corporation, used to identify a Steam integration.

Publishing a new version

Staging and publishing are driven from the engine and registry repositories:

# engine repo - stage and validate, emitting machine-readable output
python Utilities/PackageInspector.py <staged-package-dir> --json <out>.json

# registry repo - upload blobs and record the release
python tools/publish_package.py <out>.json

Versions are immutable. A mistake is fixed by publishing a new patch version, never by replacing an existing one.