The 'can't kill the enemy / no visible damage' cluster, root-caused and fixed
faithfully:
- STEP-6 unaimed path was INERT: the cylinder table was 'cached' at Wword(0x111)
-- the recon ABSORBER bank (stores nothing, reads 0) -- so every unaimed hit
silently no-op'd. Promoted to the named member Mech::damageLookupTable
(binary this[0x111], was mislabeled ammoExpended). New gotcha class recorded
(reconstruction-gotchas §2) + sweep; 2 dead multiplayer branches logged.
- Fire path migrated off the stale vital-zone aim onto the completed STEP-6
unaimed dispatch (zone=-1 + beam entry point -> cylinder resolves the
exterior zone). No more invisible 1-shot kills; death via the authentic
cascade (~14 center-mass hits). Wreck stays TARGETED on kill (beams stop on
it); scoring latches off.
- SendSubsystemDamage AV fixed: unbound critical-subsystem plug guard (43
unbound plugs/mech logged as an open question -- the binding itself is a gap).
- RemakeEntity (render damage swap): the 1996 render state machine's missing
Remake state, reconstructed as an in-place SetDrawObj mesh swap keyed by each
segment's damage-zone graphic state (tree dtor doesn't cascade -> never
rebuild). Destroyed arms/guns visibly wreck (the only variants the RES
registers).
- BT .PFX particle layer (L4VIDEO.cpp): the 1995 explosion/damage effect layer,
unported since 2007 (DPLIndependantEffect/ReadPSFX/ExplosionScripts all
stubs). Parses the authentic VIDEO/*.PFX definitions via the [pfx_day]
psfxN mapping; premultiplied blending renders BOTH families from the same
data (additive-style fire + occluding smoke -- DDAM2 is 30% grey, DDTHSMK
ramps negative: impossible additively); depth-sorted billboards with a
radial-masked grit sprite; impact-frame orientation (.PFX offsets are
authored mech-local, -Z = out of the struck armor toward the shooter) for
weapon hits AND damage bands (via lastInflictingID, now maintained -- was
declared but never written). Both effect-number encodings route (raw dpl
<100 + WinTesla 1000+slot carried by the band resources). Death fires the
authentic dnboom (7) + ddthsmk smoke plume (1).
- Effects anchor at the impact point / damaged zone's segment, not the mech
origin (no more fire at the feet).
- Dev force-input gates BT_AUTOFIRE / BT_AUTODRIVE for headless fire-chain
verification; BT_PFX_ADD=1 flips the particle blend for A/B.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Fixes the "kills are invisible" report: a mech died only at the state level, with
no visible destruction on its body. Root cause: the per-zone damage-state
descriptor table (binary zone+0xd4) that drives destroyed-skins + explosions was
never built -- its loader (Mech__DamageZone::LoadCriticalSubsystems / FUN_0041e4a8)
was a no-op stub, and MechDeathHandler itself was a no-op stub. The surrounding
plumbing (the per-zone load loop over the type-0x1e resource, the death-handler
slot) was already correct. Whole pipeline is EXPORTED -- no stand-ins.
Reconstructed:
- Mech__DamageZone descriptor table (binary this+0xd4): un-stubbed
LoadCriticalSubsystems (FUN_0041e4a8/FUN_0042a748/FUN_0042a2c8) to parse the
real type-0x1e stream -- entry = [f32 DamageLevel][i32 EffectResource]
[i32 GraphicState][f32 TimeDelay], ascending by DamageLevel. Verified live:
6 entries/zone, first threshold 0.2, effect 26, across all 40 zones, no crash.
- The three lookups (FUN_0042a664 by-level / FUN_0042a5f4 crossing / FUN_0042a6c4
by-graphic-state) as Mech__DamageZone methods.
- The real MechDeathHandler (FUN_0042a984 ctor / FUN_0042aa2c Performance /
FUN_0042a9f4 dtor), replacing the stub: each tick it walks the zones and, as a
zone's damageLevel rises across a descriptor threshold, fires that entry's
explosion (binary +0xb8 & 4) and, on destruction, the Destroyed-graphic
descriptor's explosion (+0xb8 & 8), applying the descriptor's GraphicState (the
destroyed skin) to the zone. Runs for EVERY mech, so the enemy visibly falls
apart as it dies.
Integration: the binary ticks MechDeathHandler off the mech's Performance list
(mech+0xbc), which the bring-up drive override bypasses, so Mech::PerformAndWatch
drives Tick() directly (same approach as UpdateDeathState). Effect spawn uses the
established Explosion::Make port (BTSpawnDamageEffect) -- the authentic dispatch
(class-5 message -> the 0xBD3 SubsystemMessageManager effect manager) is unported.
Runtime: builds clean, boots clean, 42 descriptor tables load with sensible
byte-aligned data, no crash. Live effect firing is combat-triggered (verified by
the load + the wiring; the [deathfx] threshold-crossing log fires under BT_DEATH_LOG).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Clean, self-contained extraction of the BattleTech-specific work from the
reverse-engineering workspace -- engine + game + content + build, with nothing
from Red Planet or the raw archive dumps. Builds green (Win32) and runs the
single-player drive->animate->target->fire->damage->destroy loop out of the box.
Layout:
engine/ MUNGA + MUNGA_L4 shared 2007 engine, carrying our BT render/loader
work (bgfload/L4D3D/L4VIDEO: BSL bit-slice decode, LOD/ground/shadow
models) + image codec; the minimal rp/ headers the audio HAL needs
game/ reconstructed BT logic + surviving-original BT source + fwd shims
+ WinMain launcher
content/ full runtime tree (BTL4.RES, VIDEO/, GAUGE/, AUDIO/, eggs, BTDPL.INI)
docs/ format specs + reconstruction ledgers
reference/ raw Ghidra pseudocode (recon source-of-truth) + decomp exporter
tools/ MP console emulator + map/resource scanners
One top-level CMake builds munga_engine lib + bt410_l4 game lib + btl4.exe.
All paths relativized (186 fwd shims + ~437 CMake abs paths -> repo-relative);
DXSDK is the one external, overridable via -DDXSDK. Verified: builds to a
byte-identical 2.27MB exe and runs combat (TARGET DESTROYED, 0 crashes) against
the bundled content.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
