Joe DiPrimaandClaude Opus 5
1777d5a62e
Conn Man crashed twice in an Owens on 2026-07-27, kept playing, and by the time
we asked for his logs they no longer existed. Not a mystery: every launcher did
if exist content\X.old.log del content\X.old.log
if exist content\X.log ren content\X.log X.old.log
which keeps TWO generations. He relaunched more than twice, so his own bat
deleted both crash sessions. The player who crashes is exactly the player who
relaunches immediately, so the retention window was aimed at the wrong case.
THE LOG. BT_LOG set still means "use this path verbatim" -- that contract is
load-bearing (mp_a.log/mp_b.log for 2-node runs from one cwd, btoperator's
operator_N.log, every scratchpad/mp_*.sh that greps the file it named) and is
untouched. Only when BT_LOG is UNSET does the exe now name the file itself:
content\<stem>_YYYYMMDD.log, appended, one per day, no rotation window to fall
out of. The stem (solo/join/steam/joyconfig) comes from the gates the bat
already sets, so solo still cannot overwrite the MULTIPLAYER log.
Self-named files append UNCONDITIONALLY. The default open mode is ios::out --
TRUNCATE -- and the operator GUI's exported bats never set BT_LOG_APPEND, so
they were truncating already; leaving append implicit would have let the second
launch of the day erase the morning.
IDENTITY, because these arrive from many players at once and Discord renames
half of them to message.txt (most of the night-5 evidence had to be
re-identified by hand):
===== BT411 SESSION build=4.11.603 (d64d75f+) machine=... user=...
callsign=Conn Man mode=solo pid=13192 local=... log=... =====
Also the session separator inside a per-day file, and it puts build+hash ABOVE
any [crash] block so btl4+0xNNNN offsets stay matchable to a PDB across builds.
SIZE. Never delete, but stay sendable: past 8 MB the next launch rolls to
<stem>_YYYYMMDD.1.log. Checked only at open, so a live session is never split.
CONSOLIDATION. launch_report.txt is gone, folded into lastrun_<stem>.txt (one
launch record: the exe appends its block at first breath, the bat appends the
exit line). Per-stem because one shared lastrun.txt let a second launcher's
`del` destroy the first launch's block. Its ABSENCE after a run is now the
#41 "never reached WinMain" probe -- the old "if not exist X.log" test cannot
work against a per-day file, which survives earlier launches, and would have
reported every healthy run as blocked by antivirus. marshal.log folded into
the day log too; it keeps its own handle and gained a CRITICAL_SECTION because
it runs on a worker thread while the engine log stream is single-threaded.
play_steam.bat gained a launch bracket it never had -- which is why a Steam
player killed before WinMain previously left no evidence at all.
_putenv_s, not SetEnvironmentVariableA, to pin the resolved name: MSVC's CRT
keeps its own environment copy, so getenv() in-process does NOT see a
SetEnvironmentVariableA write (measured). btl4console/btl4lobby resolve the
day log via getenv, so with the Win32-only call they silently fell back to
marshal.log and the fold never happened.
logfile.open() is now checked -- a failed open used to rebind cout to a dead
buffer, silently dropping the header, [boot] and any crash stack while
lastrun still claimed log=<name>.
Verified: append across sessions with distinct pids, crash block landing under
its own header, BT_LOG verbatim unmangled, an inherited BT_LOG cleared by the
bats, roll-over at 8 MB, and both forensic verdicts (exe ran / exe blocked).
Console auto-retrieval is unaffected -- it uploads the matchlog, a different
file, and a crashed round never reaches the upload call anyway.
Known gaps, deliberately not in this commit: the setlocal hoist for gate
leakage when two bats share one console (dev-only), and btoperator's exported
bats still lack the lastrun bracket -- do not press Export on a shipped zip.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
BattleTech 4.11 (bt411)
A standalone Windows port of Virtual World Entertainment's arcade BattleTech (Tesla platform, release 4.10, ~1995–96), reconstructed on the shared RP411 Windows engine. The game boots, renders, and runs a single-player drive → animate → target → fire → damage → destroy loop across all 8 maps, with two-instance multiplayer entity replication working.
This repo is a clean, self-contained extraction of the BattleTech-specific work from the larger reverse-engineering workspace — engine + game + content + build, with nothing from Red Planet or the raw archive dumps. It builds and runs out of the box.
License: the game content (
content/) and the original binary are proprietary to Virtual World / the pod owner. This repository is private; do not redistribute.
Versioning
4.10 = the 1995 arcade release. 4.11 = this win32 reconstruction. Dev builds are
4.11.<build> where <build> is the git commit count — monotonic and zero-maintenance —
plus the short commit hash (4.11.311 (980c9cd)); a trailing + on the hash means the exe was
built from an uncommitted working tree. The stamp regenerates every build
(tools/btversion.cmake → build/btversion.h) and shows in the boot banner (btl4.log line 2)
and the window title. To identify any player's build, ask for the title bar or the top of their
btl4.log.
Layout
CMakeLists.txt one build: munga_engine lib + bt410_l4 game lib + btl4.exe
engine/
MUNGA/ shared 2007 sim/render engine (149 .cpp + headers)
MUNGA_L4/ Win32/D3D9 HAL + renderer + asset loaders (44 .cpp), incl.
our BT work: bgfload / L4D3D / L4VIDEO + the image codec
shim/ minimal ATL shim (USES_CONVERSION/W2A)
lib/ OpenAL32 / libsndfile import libs + runtime DLLs
game/
reconstructed/ the reconstructed BT game logic (mech, subsystems, HUD, app; ~47 .cpp)
original/BT,BT_L4 surviving original BT source + all BT headers
fwd/ header shims forwarding <NAME.hpp> -> the engine's NAME.h
btl4main.cpp WinMain launcher / entry point
content/ runtime data: BTL4.RES, VIDEO/, GAUGE/, AUDIO/, *.EGG, BTDPL.INI
context/ progressive knowledge graph — 18 on-demand topic files (routed by CLAUDE.md)
docs/ format specs + reconstruction ledgers + PROGRESS_LOG.md (full history)
reference/
decomp/ raw Ghidra pseudocode — source-of-truth for ongoing recon
ghidra_scripts/ the headless decomp exporter
glossary.yaml term / acronym definitions
phases/ restructuring / investigation logs
tools/ btconsole.py (MP console emulator), map/resource scanners
run/ run.cmd helper
CLAUDE.md knowledge-base ROUTER — identity, protocols, quick-lookup, conventions
Prerequisites
- Visual Studio 2019 BuildTools (MSVC v142, x86). The Community install on the original dev box was broken, hence the explicit BuildTools instance in the configure line below; adjust to your install.
- CMake ≥ 3.20.
- Legacy DirectX SDK (June 2010) — the engine uses
d3dx9/dinput/dxerr, removed from the modern Windows SDK. Default pathC:/Program Files (x86)/Microsoft DirectX SDK (June 2010); override with-DDXSDK=<path>. (The installer may throw a harmless S1023 error — dismiss it; the SDK headers/libs install before the failing redist step.)
OpenAL/libsndfile import libs + DLLs are vendored under engine/lib/; the DLLs are copied next to
the exe automatically at build time.
Build (32-bit / Win32)
cmake -S . -B build -G "Visual Studio 16 2019" -A Win32 ^
-DCMAKE_GENERATOR_INSTANCE="C:/Program Files (x86)/Microsoft Visual Studio/2019/BuildTools"
cmake --build build --config Debug
Must be Win32 — the DirectX SDK link libs are Lib/x86. The link uses /FORCE: the 1995
headers define free functions/globals without inline/extern, so identical symbols appear in
many translation units (~124 LNK2005); /FORCE:MULTIPLE keeps the first. UNRESOLVED tolerates
a dead offline-tool factory in mech3.cpp that is never called at runtime. (Cleanup task: move
those definitions to single TUs + neutralize the dead factory, then drop /FORCE.)
Run
run\run.cmd REM boots DEV.EGG (grass / day)
run\run.cmd DBASE.EGG REM any egg in content/
The working directory must be content/ (the engine resolves BTL4.RES, VIDEO\,
BTDPL.INI, and eggs relative to cwd); run.cmd handles that. Maps available in BTL4.RES:
cavern grass rav polar3 polar4 arena1 arena2 dbase — switch via a copied egg's map= field.
Useful env-var flags (default OFF unless noted)
The authentic stack (gait, collision, real controls) is default-on; set =0 to fall back.
Debug/harness flags: BT_FORCE_THROTTLE=1 (auto-walk), BT_SPAWN_ENEMY=1 (spawn a target dummy),
BT_FORCE_FIRE=1 (auto-fire), BT_HEAPCHECK=1 (whole-heap validation — slow), BT_BSL=0 (legacy
texture decode), BT_DEV_GAUGES=1 (render the cockpit MFDs in a dev window), BT_LOG=<file>.
Interactive: WASD drive, A/D turn, Q/E torso twist, R/F torso pitch aim,
Space / 1-4 fire, X all-stop, V view, M control mode. An Xbox-type controller
works out of the box. All bindings are user-editable in content/CONTROLS.MAP (delete it to
restore the compiled-in WASD default; content/CONTROLS_NUMPAD.MAP is an alternate profile). The
complete env-gate table is in context/decomp-reference.md §6 (routed from CLAUDE.md);
controls/pad details in context/pod-hardware.md.
Multiplayer
Modern path (relay + operator console). Pods make ONE outbound connection to a relay/console, so internet play needs no per-player port forwarding and CGNAT-safe LAN discovery just works. Run the operator station:
python tools/btoperator.py # PySide6 GUI: build the mission egg (validated dropdowns),
# start the relay, watch pods arrive, assign seats, LAUNCH,
# end the timed mission, export player join.bat scripts
Players run one universal join.bat (internet, seat assigned by the relay) or join_lan.bat
(same LAN, auto-discovers the console) or play_solo.bat (offline practice) — see players/.
The pod waits patiently if the session isn't up yet. Full architecture, wire format, and the
D1 relay/UDP design: context/multiplayer.md.
Legacy mesh (two instances, one box), still supported:
instance A: btl4.exe -egg MP.EGG -net 1501 (BT_LOG=mp_a.log)
instance B: btl4.exe -net 1601 (BT_LOG=mp_b.log)
console: python tools/btconsole.py MP.EGG 127.0.0.1:1501 127.0.0.1:1601
-net <port> enables networked mode. Verified end-to-end: full entity/movement replication,
cross-pod combat + kills, per-pilot paint + callsigns, timed missions, 4-pod live sessions, and a
spectator/broadcast camera seat (hostType=1 vehicle=camera) with auto-directed coverage and
a live ranking window.
Status & continuing the work
The engine, renderer, audio, HAL, build, locomotion, collision, damage, render fidelity, the full
cockpit gauge / MFD system (every config binding resolves + every widget builds), and the
projectile / missile weapon families are done. Active fronts: per-subsystem polish (the gyroscope
integrator; the 0xBD3 message manager that gates the valve / status-message control routes) and
cross-pod MP combat. reference/decomp/ holds the raw pseudocode every reconstruction is verified
against.
Start with CLAUDE.md — it is the router into the progressive knowledge base: a quick-lookup
table pointing to the context/*.md topic files (loaded on demand), the evidence-tier and
convention rules, and context/open-questions.md for what's deferred / next. The complete
pre-restructure history is preserved verbatim in docs/PROGRESS_LOG.md; docs/*.md holds the
detailed running ledgers.