BT412/context/build-and-run.md

id, title, status, source_sections, related_topics, key_terms

id	title	status	source_sections	related_topics	key_terms
build-and-run	Build / Run / Debug — recipe, repo layout, env gates	established	PROGRESS_LOG.md §10a, §10a-bis; README.md	wintesla-port decomp-reference reconstruction-method	BTL4OPT cdb BTL4.RES EGG WinTesla

Build / Run / Debug

The one top-level CMakeLists.txt builds munga_engine (engine) + bt410_l4 (reconstructed BT game lib) + btl4.exe. Full recipe + repo-layout map: docs/PROGRESS_LOG.md §10a / §10a-bis + README.md. Env-gate table: decomp-reference §6.

Build (Win32 / VS2022 BuildTools — the DXSDK link libs are Lib/x86)

# configure once (BT412 toolchain of record, moved from VS2019/v142 at the 4.12 fork):
cmake -S . -B build -G "Visual Studio 17 2022" -A Win32 \
  -DCMAKE_GENERATOR_INSTANCE="C:/Program Files (x86)/Microsoft Visual Studio/2022/BuildTools"
# build:
cmake --build build --config Debug

Build flavors — the BT412 compile gate (2026-07-17, merge-back into BT411)

One tree builds both lines; option(BT412 ... ON) gates the steamification layer. [T2]

• Default (BT412=ON) — pod/dev game + PadRIO/plasma/front end/lobby (all runtime-gated; a -egg/-net launch behaves as 4.11). Compile definition BT412 set on all 3 targets.
• Pod-minimal (-DBT412=OFF, dir build-pod/) — compiles OUT L4PADRIO, L4PADBINDINGS, L4KEYLIGHT, L4PLASMASCREEN, L4STEAMTRANSPORT, btl4fe, btl4console, btl4lobby. Seam sites carry #ifdef BT412: L4CTRL.cpp PAD token (log + ignore), L4GREND.cpp L4PLASMA=SCREEN (log + ignore), L4VB16.cpp (inert PadRIO stub struct — call sites identical in both flavors), btl4main.cpp (front-end/marshal/lobby blocks compile out; zero-arg launch = 4.11 behavior). The NetTransport seam always compiles — it is the wire for both flavors (WinsockNetTransport verified byte-identical to pre-seam arcade behavior). Verified: clean v143 link (no unresolved), solo -egg DEV.EGG runs (31 subsystems tick, gait, targeting).
• Steam (-DBT412_STEAM=ON, dir build-steam/) — requires BT412=ON (configure-time FATAL_ERROR otherwise; negative-tested).
• Links DXSDK d3d9/d3dx9/dinput8 + OpenAL/libsndfile (engine/lib/). DXSDK June 2010 at C:\Program Files (x86)\Microsoft DirectX SDK (June 2010)\ (overridable -DDXSDK). [T2]
• Linker uses /FORCE:MULTIPLE — tolerates the ~124 header-defined-global LNK2005s. UNRESOLVED is gone (BT412, 2026-07-14): the v143 linker refuses to emit an image with unresolved externals even under /FORCE, so the dead offline-tool ladders in mech3.cpp (Mech::CreateSubsystemStream / Mech::SubsystemDefaultData — never called at runtime) are compiled out behind BT412_OFFLINE_TOOLS (default off). A genuinely unresolved symbol is now a hard LINK ERROR, not a hidden runtime AV — the reconstruction-gotchas §6 hazard class is retired for the exe link. No other source changes were needed for v143 (verified: clean build, solo DEV.EGG run, two-instance loopback MP with replication). [T2]
• Editing an engine/ file rebuilds the engine lib automatically (one project). A NEW member on a DPLRenderer/d3d_OBJECT class needs the game objs that embed its layout recompiled — delete stale objs if layout-mismatch corruption appears. [T2]
• ⚠ Kill the running exe before rebuilding (taskkill //F //IM btl4.exe) or you get LNK1104.

Run

run\run.cmd [EGG]      # default DEV.EGG; cd's to content\ and runs btl4.exe -egg <EGG>

• cwd MUST be content\ — the engine resolves BTL4.RES, VIDEO\, BTDPL.INI, eggs relative to cwd (the loadTables gotcha: L4VIDEO.cpp:849 fopen("VIDEO\\REPLACEMATS.tbl") is relative + unchecked → fread on NULL if cwd is wrong). Logs to btl4.log in content\ (or BT_LOG=<file>). [T2]
• Interactive: WASD drive; weapon groups (keyboard, task #43) 1/Space = lasers, 2 = PPCs, 3/Ctrl = missiles; X all-stop; V cockpit/chase view. Default egg = DEV.EGG (map=grass, time=day). Swap mech via the egg's vehicle= (bhk1/madcat/…). The code path is mech-agnostic (verified — Mad Cat booted + fought with zero code changes). [T2]

Debug (cdb x86)

"C:\Program Files (x86)\Windows Kits\10\Debuggers\x86\cdb.exe". Pattern for a faulting stack (cwd = content): -g -c ".lines;sxe av;g;kp 24;q" with BT_ASSERT_TO_DEBUGGER=1. Debug CRT fills fresh heap 0xCDCDCDCD (uninit) + freed 0xFEEEFEEE — invaluable for "was this ever constructed?". BT_HEAPCHECK=1 = whole-heap validation every alloc/free (O(n²) at mission load — SLOW). To attach to a frozen abort dialog: cdb -p <pid> -c ".lines;~*kp 30;q". [T2]

Repo layout (bt411)

• engine/MUNGA/ + engine/MUNGA_L4/ — the shared 2007 MUNGA engine + Win32/D3D9 HAL (carries our BT render/loader work: bgfload/L4D3D/L4VIDEO + the image codec). engine/shim/ (ATL), engine/lib/ (OpenAL/libsndfile), engine/rp/ (RP headers the audio HAL includes).
• game/reconstructed/ — the reconstructed BT source (the bulk).
• game/original/BT/ + BT_L4/ — surviving original BT .cpp + all BT headers (the include path).
• game/fwd/ — ~186 forwarding shims (#include <EXPLODE.hpp> → ../../engine/MUNGA/<NAME>.h).
• game/btl4main.cpp — the WinMain launcher.
• content/ — the runtime tree (BTL4.RES, VIDEO/, GAUGE/, AUDIO/, eggs, BTDPL.INI). Run cwd.
• reference/decomp/ — the raw Ghidra pseudocode (all/part_*.c) — the source-of-truth.
• docs/ — the detailed ledgers (incl. PROGRESS_LOG.md, the full pre-restructure CLAUDE.md).
• tools/ — btconsole.py, disas2.py, map/res scanners. context/ — this knowledge base.

Key Relationships

• Base: wintesla-port (the engine build recipe).
• Verify loop: reconstruction-method; env gates: decomp-reference §6.