Simulation::ReadUpdateRecord threw away the sender's timestamp and
stamped lastUpdate with its own arrival time. The line carried the
original authors' own note: "HACK - should be based upon
message->timeStamp".
The dead reckoner extrapolates a replicant over
(lastPerformance - lastUpdate), so starting that clock at ARRIVAL rather
than at SEND leaves every remote vehicle exactly one network latency
behind where it should be. On the 1 ms LAN inside an arcade that is
nothing. Over Steam Datagram Relay it is 50-150 ms of positional lag on
every other player - a constant bias, not jitter, and the information
needed to remove it was already in the packet.
The timestamp cannot be used as it stands: both machines run
QueryPerformanceCounter since their own boot, so the two clocks share no
epoch. The offset is estimated per peer instead. Each record gives
sample = ourNow - theirStamp = trueOffset + oneWayLatency
and latency is never negative, so the smallest sample seen is the
closest to the truth. A rolling minimum over 128 samples follows crystal
drift and re-adapts when a route gets slower, rather than being pinned
forever by one lucky packet; a shorter path is believed immediately.
Applied with two clamps: never ahead of our own clock, and never further
back than 500 ms. Past that the packet is stale or the estimate is
wrong, and throwing a vehicle half a second forward does more damage
than the lag being corrected.
Entity::UpdateMessageHandler is the only point on the receive path that
knows whose update this is - records carry a timestamp but not an owner -
so it publishes the sender around the loop, and only for entities
somebody else owns. Offsets are forgotten in CreateMission: the hosts in
the next race are not the hosts in the last one and a HostID gets reused.
RP412NETCLOCK=0 restores the arrival-time behaviour, documented in
environ.ini, so a test machine can compare the two without a rebuild.
The estimate is logged per host when it first settles and whenever it
moves more than 50 ms, which is what a three-machine session should be
read against.
WHAT IS AND IS NOT VERIFIED. A full single-player race runs unchanged -
the path is never entered without replicants, which is the regression
risk that reaches everybody. The behaviour this exists for needs real
latency between real machines and is therefore untested: a two-instance
loopback race would only have exercised the zero-latency case, where the
correction is a no-op by construction. Expect remote vehicles to sit
further forward than before, and watch for overshoot when somebody
changes direction sharply - that is the tradeoff this makes, and the
clamp above is what bounds it.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Red Planet 4.12 — the Steamification
Red Planet is VWE's pod-racing game: eight-player VTV contests on Mars — Martian Death Race and Martian Football — originally played from inside VWE Tesla cockpit pods. This repo is the third life of that code:
| Generation | What it was |
|---|---|
| Red Planet 4.10 | The original game, running on the Tesla 1 pod platform (DOS-era MUNGA engine, serial RIO cockpit hardware, operator console, batch-file relaunch between missions) |
| Red Planet 4.11 | The Win32 port of 4.10 (RP411) — DirectX 9, WinSock TCP, TeslaConsole/TeslaLauncher session control; still runs in pods, still a LAN |
| Red Planet 4.12 | This repo: the Steamification of 4.11 — the same engine, the same wire protocol, the same missions, made distributable on Steam and playable over the internet with no cockpit hardware |
The architecture is deliberately conservative: the VWE's design survives intact, with each pod-era dependency replaced by a consumer equivalent behind the engine's existing seams.
| Arcade (4.10/4.11) | 4.12 replacement |
|---|---|
| RIO cockpit board (serial) | PadRIO — virtual RIO from XInput pad + keyboard, fully rebindable (bindings.txt, vRIO profile format) |
| Seven physical displays | Single-window cockpit — all displays composed on a locked 1920×1080 canvas around the viewscreen, with the real button banks lamp-lit and clickable |
| Pod button lamps | On-screen lamps, plus an RGB keyboard mirror (Windows Dynamic Lighting) |
| TeslaConsole operator | In-game front end — race setup menu builds the mission egg locally; an in-process console marshals every race (missions still only end on a console stop, exactly as designed in 1994) |
| TeslaLauncher relaunch-per-mission | Single binary — menu → race → results → menu in one process |
| WinSock TCP LAN mesh | NetTransport seam — the deterministic pod mesh unchanged, running over plain TCP (LAN/dev) or Steam Networking Sockets (FakeIP + Steam Datagram Relay) |
| Site network / fixed IPs | Steam lobbies — lobby owner is the console; members exchange FakeIPs and loadouts as lobby data |
Status: it works. v4.12.2 carried the first verified end-to-end internet build: three machines, three Steam accounts, lobby → mesh → marshaled five-minute race → deaths and respawns → timed stop → results on every machine → rematch from the same lobby.
v4.12.3
is about the screen. The cockpit now scales up as well as down and re-fits
whenever the window changes, keeping 16:9 so a wide panel letterboxes
instead of stretching; -fit runs it borderless over the whole monitor and
picks the render size to land on the viewscreen 1:1. The displays are the
player's to arrange — each of the six can be scaled on its own and the
radar moved out of the middle of the road (environ.ini). Each display's
button bank now reaches under its glass, so the picture itself is the press
target rather than a sliver at the edge.
v4.12.4 is about the lobby. Both rooms now show the host's mission setup — the track, then time of day, weather and game length — since everyone flies the owner's picks and it was the one thing in the room nobody could see for themselves. The football team sheet names each player's VTV beside their team colours and position. And a lobby holds eight players rather than four, a full grid as the pod hall ran it, with the room sizing its roster to whatever space the window gives it.
v4.12.5 restores the Winners Circle. The pod hall stood the finishers on a numbered award platform when the race ended, and all of it was still in this repo — the stand, eight ranked spots in every map, and the code to put racers on them — wired only into the mission-review build and so never once run by a pod. The race now fades out and fades back in on the platform: finishers in finishing order, each pilot's callsign on the plate beside their spot, the cockpit glass cleared away, held for a few seconds before the results screen. Three pieces of it had been stubbed out in the D3D9 port and are working again.
v4.12.6
is about the windows. Where you put them now survives the
menu-race-menu loop: RP412MFDLAYOUT remembers the game window, the
exploded view's display panes and the plasma glass in mfd_layout.cfg
beside bindings.txt. Append ,noframe to a line to take that
window's title bar and border off — a cockpit filling the monitor edge
to edge at a rect you chose, rather than -fit taking the whole
screen — and the setup screen carries its own EXIT GAME button,
since a window with no title bar needs a way out. The Steam buttons
now dim and say STEAM NOT RUNNING instead of disappearing. And the
Winners Circle camera is framed off the award stand itself rather than
off whoever is standing on it, so the shot is the same one for every
player at every head count.
v4.12.7
is about sticks. Anything that is not an Xbox-class pad — a flight stick,
a HOTAS throttle, a twist grip, rudder pedals, a wheel — comes in through
DirectInput rather than XInput, and the game could not see any of it.
Now it can, and joyconfig.bat sets it up: the wizard asks you to move
each control in turn, works out which device and axis answered and which
way round it reads, and writes the joystick rows of bindings.txt,
leaving anything you have edited yourself alone. A twist grip or rudder
bar drives both pedals through one signed Pedals axis, and a real
throttle lever owns its channel outright rather than nudging a position
the way a spring-centred stick has to. Ported from the sibling BT411.
Playing
Grab the release zip (or run pack-dist.ps1 on a build). Single player:
run start-windowed.bat — the game boots into the setup menu, where the
SCENARIO group picks Death Race or Football (Football swaps in the
team/position columns and its own track list). Steam multiplayer: see
docs/STEAM-3-MACHINE-TEST.md (until RP412
has its own AppID it runs under Spacewar, 480).
The config files beside the exe are self-documenting and none of them ship: the game writes each one the first time it needs it and then leaves it alone, so a new build dropped over an existing folder keeps every setting. environ.ini is every engine option, commented; bindings.txt every key, pad button and axis; pilot.cfg your callsign and loadout; mfd_layout.cfg where you dragged the windows. Delete any of them to start that part over with the current defaults. Default controls: numpad flies (8/2/4/6 stick, 7/9 pedals, 0 trigger), Shift/Ctrl throttle, Alt reverse, arrows look, Space fires, letter rows are the MFD button banks as printed on the panel. Alt+Q aborts a mission. Full map with pad and keyboard diagrams: docs/CONTROLS.md.
Building
VS 2022 (v143) + DirectX SDK June 2010 + the vendored Steamworks SDK
(extern/steamworks_sdk_164) — see BUILD.md. Solution
WinTesla.sln, configuration Release|Win32, output
Release\rpl4opt.exe.
Documentation
| Doc | Contents |
|---|---|
| docs/CONTROLS.md | Controls map — pad and keyboard diagrams, the panel button banks, rebinding |
| docs/RP412-ROADMAP.md | The original plan and workstreams |
| docs/RP412-FRONTEND-DESIGN.md | TeslaConsole analysis, the egg format, the console protocol, and the Steam mapping — with status notes as each layer landed |
| docs/STEAM-3-MACHINE-TEST.md | Multiplayer test procedure, Steam Input notes, the abort key |
| BUILD.md | Toolchain and build steps |
Dev tooling: tools/two-pod-test.ps1 races two pods on loopback,
marshaled by a console feeder speaking the arcade Munga protocol.
Related repositories
| Repo | Role |
|---|---|
| RP411 | Upstream: the Win32 arcade port this repo Steamifies (full history preserved; remote rp411 for cross-pulling fixes) |
| VRIO | Virtual RIO panel + vPLASMA — source of the bindings format, the cockpit layout, and the keyboard lamp mirror |
| TeslaSuite | TeslaConsole / Launcher / vPOD — the arcade session-control stack 4.12 absorbed (and the reference implementation of the Munga control protocol, TCP 1501) |