The Mech per-impact hit-location resolver (the cylinder damage table) is now
functional, wired, and runtime-verified [T2]. Unaimed (zone==-1) hits — the
collision-damage path — now resolve an impact point to a damage zone via the
authentic height x angle grid + weighted dice roll, instead of dropping.
dmgtable.cpp/.hpp was a non-functional skeleton on no-op ReconTable/stream
shims; backed it with real std::vector storage and fixed 5 latent runtime bugs:
- ReadEntries now consumes the leading cell name-string ([i32 len][len+1])
- PieSlice ctor reads rotateWithTorso into the correct member
- SelectSlice direct-indexes (was int lookup on a float-keyed table)
- ResolveHit returns the zone (chains SelectSlice -> SelectZone)
- real MemoryStream::ReadBytes (was a variadic no-op)
mech.cpp ctor: replaced the empty-name StandingAnimation stub with the real
load — FindResourceDescription(dzRes->resourceName, type 0x1d) -> stream ->
new DamageLookupTable, cached at mech[0x111]; ~Mech deletes it.
Mech::TakeDamageMessageHandler override registered (MESSAGE_ENTRY overlays
Entity's by ID): on invalidDamageZone, resolve via the table then base-route;
aimed reticle hits pass through unchanged.
Three named accessors (no databinding-trap raw reads): WorldToLocal
(localToWorld.MultiplyByInverse), CylinderReferenceHeight (standingTemplateMaxY
== collisionTemplate->maxY == binary mech+0x2ec[+0xc]), TorsoHeading via a
BTGetTorsoTwist bridge in torso.cpp (Torso::CurrentTwist == torso+0x1d8;
torso.hpp cannot be included into mech.cpp — subsystem-stub collision).
Stream format + geometry + roll + handler were all byte-verified against the
shipped BTL4.RES type-29 resources (18 tables, exact consumption) and the
disassembly (FUN_0049eb54/e678/de14, glue 0x49ed0c, handler @0x4a037a).
Runtime: boots clean, "[cyl] table 'bhk1' layers=7" (exact byte-verified layer
count, found by name), mech spawns + walks, no asserts/AV/0xCDCDCDCD. Env gate
BT_CYL_LOG=1. Unblocks collision-damage application.
KB updated (combat-damage.md STEP 6 COMPLETE, open-questions.md marked done).
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>
