The Gyroscope subsystem is LIVE again (was a stub since the NaN revert).
Reconstructed byte-exact from @004b3778 / @004b2ec0 / @004b30ec / @004b33e0 /
@004b34ec + the byte-verified dispatch in the unexported Mech performance
FUN_004a9b5c (calls @0x4aaf74/0x4aaf83):
- ctor field map corrected: springConstant@0x1E8 / dampingConstant@0x1F4 were
mislabelled (the old 'eyeOrientation = r->springConstant' poison line), the
0x254-0x2B3 block (externalPitchPtr, work matrix, placement) was missing so
everything after was mis-offset, and clamps/accumulators were 0xCD fill --
every field now initialised per the binary; 33 offsets static_assert-locked,
sizeof == 0x3D0 exact
- integrators: state-minus-target displacements, componentwise damping
OVERWRITE (FUN_004086d0 is a component multiply, not a cross), position step
without dt, clamp to [posSpring, negSpring]; IntegrateBody's X/Z-crossed
force + integration terms
- writers: WriteMechJoint drives ONE node ('jointeye', type 5): TRANSLATION =
eyePosition spring, ROTATION = bodyOrientation spring; WriteEyeJoint is a
multiplicative sway attenuator on 'jointlocal' (post-anim only)
- dispatch moved out of GyroscopeSimulation into the Mech performance tail
(GyroFrameJointWrite bridge, mech4.cpp) with the binary gates; gyro<->torso
pitch link wired (gyro+0x258 = &torso currentTwist) via complete-type-TU
bridges, retiring the SubProxy::linkTarget landmine
- Mech ctor: deathAnimationLatched/legResetLatch were never initialised --
0xCDCDCDCD gated the writers off silently
Runtime-verified: joints resolve (both BallTranslation), Performance installs,
WriteMechJoint finite from frame 0 (no NaN), Madcat cockpit un-regressed,
combat targeting healthy. Empirical: spring targets are SYMMETRIC -> eye
equilibrium (0,0,0), clamps +/-0.1-0.15u -- the gyro is the hit-BOUNCE
mechanism, not a steady eye offset (hypothesis disproven, recorded in KB).
Pending (task #56 tail): the damage->gyro fan-out FUN_004b2980 (unexported
gap) so hits actually kick the springs; the mech+0x3F0 overspeed sway model;
the torso-pitch EyepointRotation writer (FUN_004b66b4) + glance-look states.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
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>
