CydandClaude Opus 5
49d6d93414
The AppID commit claimed the switch off Spacewar meant a Steam account now had to have Red Planet on it, and that an account without it would drop to the TCP fallback. That is wrong, and it was never tested - it was reasoned from how AppIDs work in general and written down as fact, in the handbook, the environ.ini template, the README and the three-machine test doc. Cyd checked it the direct way: put 5108000 into an older dist and ran it. It behaved exactly as it had under 480. SteamAPI_Init does not check entitlement; steam_appid.txt only tells the API which app it is. The one real difference is that the Steam client now names Red Planet instead of Spacewar. So all four places now say that, and say nothing about entitlement. The part that was always true is kept: a copy started from its own folder needs the file, and without it Steam networking cannot start and the game falls back to TCP. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
4.2 KiB
Steam multiplayer — three-machine test procedure
The full end-to-end: three machines, three Steam accounts, one lobby, one marshaled race over Steam Datagram Relay. Written 2026-07-12 for the first live test.
Per machine (all three)
- Steam client installed, logged in (different account per machine), and RUNNING.
- Copy the
dist\folder onto the machine. - Start with
start-windowed.batas usual.
The packed dist already contains steam_appid.txt (5108000 — Red
Planet's own AppID; builds before that ran under Spacewar, 480) and ships
RP412STEAM=1 in environ.ini. If a machine has an older dist, check
both before blaming the network: a missing appid file makes
SteamAPI_Init fail and the game quietly falls back to TCP.
The switch off Spacewar changes what Steam thinks you are playing and
nothing else: the client now names Red Planet on the friends list.
SteamAPI_Init does not check entitlement, so a machine behaves exactly
as it did under 480 — confirmed by dropping the new number into an older
dist, which ran unchanged.
Sanity check per machine: rpl4.log should show
SteamNetTransport: up as 169.254.x.y (fake ports N console, M game).
If it says "staying on TCP", Steam isn't running / not logged in / the
appid file is missing.
The test
- Machine A (host): pick a track, vehicle, color, pilot name on
the setup menu, then click HOST STEAM RACE. The lobby room
appears with A listed as
[HOST]. - Machines B and C: click JOIN STEAM RACE on the setup menu. (It joins the first open RP412 lobby it finds — pick loadouts on the menu BEFORE joining; the lobby publishes them.)
- When all three names show bright in A's room (bright = FakeIP published), A clicks L A U N C H R A C E.
- All three pods leave the room and boot the mission. Expect in logs:
- every pod:
SteamNetTransport: peer registeredx3 - members:
SteamNetTransport: listening on engine port 1501/1502 - A:
LocalConsole: connecting to pod 169.254...thenegg sent,EGG ACK (mesh complete)per member - everyone:
All connections completed!then the race
- every pod:
- The race runs for the length A picked; A's console stops everyone; A gets the results screen with all three personas and scores.
- Everyone lands back in the lobby room. A can launch again — different track, same lobby, no restarts.
Controllers: disable Steam Input (once per machine)
Steam Input intercepts Xbox controllers the moment the game initializes SteamAPI, hiding them from XInput entirely - the pad works everywhere else and is invisible only in-game (reproduced A/B on the dev box, under Spacewar; nothing about it was specific to that AppID). Fix, either scope:
- Per game: Steam Library -> Red Planet -> Properties -> Controller -> Override: Disable Steam Input.
- Global: Steam -> Settings -> Controller -> uncheck Enable Steam Input for Xbox controllers.
PadRIO re-probes every 3 seconds, so the pad hot-connects the moment Steam releases it - no restart needed. (Our own AppID will configure this server-side; test machines need the client setting.)
The abort key
Alt+Q aborts your mission deliberately - score banked, back to the lobby room. If the host presses it, the race ends for everyone.
(History: the legacy abort was the '&' character, and the Win32 key channel made the UP ARROW - the hat look key! - collide with it. That was every mystery abort in rounds five and six. Plain arrow keys are now safe; debug keys like wireframe/frame-dump need RP412DEVKEYS=1.)
Notes and knowns
- All pods use engine ports 1501/1502 by convention under Steam; the transport maps them to the Steam-assigned fake ports per peer.
- FakeIPs are allocated per session — they are exchanged live through lobby member data, never configured by hand.
- Same-LAN machines may get a direct route from SDR; different networks relay. Both are fine.
- Two instances under ONE Steam account cannot mesh (one identity per account) — hence three machines.
- If a member joins after A already launched once, it will answer the NEXT launch only (launch signals are nonced).
What to collect if something breaks
rpl4.log from each machine (each dist folder), plus which step of
the sequence above diverged.