arcattackandClaude Opus 4.8
1b5c3bbbd8
User observed peer warp spheres in 2-player mode; the KB (translocation-warp.md
frontmatter+body, multiplayer.md frontmatter+body) still called the peer path a
"local-player sphere stand-in until SimulationState/DropZoneLocation replication."
STALE: mechdmg.cpp:1074 fires BTStartWarpEffect at the peer's position gated to
ReplicantInstance, and simulationState rides every update-record header -- so an
observer DOES see a peer's un-wreck/respawn warp. Committed 160b78e ("observer
sees peer un-wreck"). The only genuine remainder is a [T3] fidelity nuance: the
peer sphere is anchored to the peer's WORLD position rather than the peer's
authentic (un-replicated) DropZoneLocation. (The staleness audit itself missed
this -- it trusted the file's own stale wording over its body + the code.)
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
414 lines
37 KiB
Markdown
414 lines
37 KiB
Markdown
---
|
||
id: multiplayer
|
||
title: "Multiplayer — replication, netcode, the console"
|
||
status: provisional
|
||
source_sections: "PROGRESS_LOG.md §7 (Phase 7), §8 (P6); docs/HARD_PROBLEMS.md (P6)"
|
||
related_topics: [wintesla-port, combat-damage, locomotion, decomp-reference]
|
||
key_terms: [master, replicant, EGG, dead-reckon]
|
||
open_questions:
|
||
- "pod-LAN config (real IPs); peer warp DropZoneLocation-anchoring [T3] (world-anchored peer sphere already visible, 160b78e); console-death replication freeze (pending recurrence to diagnose)"
|
||
---
|
||
|
||
# Multiplayer
|
||
|
||
Pod-to-pod networked play. The hard infrastructure exists (WinTesla replaced DOS `NETNUB` with a
|
||
WinSock2 TCP stack), and MP is now **substantially reconstructed + 2-node verified** — replication,
|
||
cross-pod combat, beam visuals, replicant gait, respawn (tasks #46-#52). Remaining: pod-LAN config,
|
||
fidelity nuances, and the Mech-level update records. Full detail: `docs/PROGRESS_LOG.md §7, §8`;
|
||
the problem writeup: `docs/HARD_PROBLEMS.md` (P6).
|
||
|
||
## The stack (already reconstructed)
|
||
- WinTesla replaced `NETNUB` with a **~3.5k-line WinSock2 TCP** reimplementation (`MUNGA_L4/L4NET.CPP`,
|
||
`SOCK_STREAM`/ReliableMode, zero SOCK_DGRAM); the master/replicant distributed-sim core
|
||
(InterestManager/Entity/HostManager) is complete. MP was integrated on that stack and verified
|
||
end-to-end 2-node. The rumored `L4NET.CPP:1853` send-size
|
||
bug is DEAD CODE (`#if MESSAGE_BUFFERING`==0). [T2]
|
||
|
||
## Master / replicant model
|
||
- **[[master]]** = a locally-simulated entity (your mech + dummies); drives itself + EMITS update records.
|
||
- **[[replicant]]** = a peer's mech, a local proxy; DeadReckons toward the master's replicated position.
|
||
MUST `SetValidFlag()` at creation or every message defers forever ([[reconstruction-gotchas]] §9).
|
||
|
||
## How a session forms
|
||
`-net <port>` = networked mode (the pod listens on <port> for a CONSOLE, boots ConsoleOnly; game mesh
|
||
= <port>+1). Solo (no `-net`) never touches WinSock. The mission egg's `[pilots]` section IS the
|
||
roster (`pilot=ip[:port]` + a per-address page); each pod self-identifies by local-IP+game-port,
|
||
connects to earlier pilots, listens for later ones — a deterministic full mesh; the mission loads when
|
||
all connect. The **CONSOLE** (operator station — ABSENT from every archive) delivers the egg as chunked
|
||
`ReceiveEggFileMessage` packets + the LAUNCH `RunMissionMessage`; **`tools/btconsole.py` is our console
|
||
emulator** (⚠ `NotationFile::ReadText` expects NUL-SEPARATED lines). [T2]
|
||
|
||
## Verified milestones (one box, two instances)
|
||
- ⚠ **`-net` node render glitch — LIKELY ALREADY FIXED / WATCHING (task #53):** a 2-node MP session
|
||
once showed ONE window come up visually wrong — shadow clipping, camera stuck inside/blocked,
|
||
targeting/firing dead — while the other was fine. Two earlier framings were WRONG and are corrected:
|
||
(i) the "two-D3D9-apps-on-one-GPU / device contention" theory was retracted — a solo instance, AND
|
||
two solo instances, are all clean, so it is not device contention; (ii) "glitched FROM LOAD, before
|
||
any death" was ALSO wrong — **the trigger is a RESPAWN** (user correction, 2026-07-10). So it is a
|
||
**post-respawn render-rebuild fault on the MP path**, not a load-time one. Does NOT affect the pod
|
||
(one instance per machine).
|
||
- **What the respawn rebuild does (reproduced 2026-07-10):** on respawn the player's mech is rebuilt
|
||
via `MakeEntityRenderables`, which runs a TWO-STEP view sequence — inside skeleton + `COCKPIT
|
||
eyepoint`, then outside skeleton + `external chase` (`[view] …` logs, btl4vid.cpp:2158) — and the
|
||
external chase camera is NOT re-installed (only ONE `[BTrender] external debug chase camera
|
||
installed`, btl4vid.cpp:647, for the whole session despite multiple respawns). Plausible failure:
|
||
if that two-step completes only to the COCKPIT step (raced/interrupted on the `-net` ladder), the
|
||
node is left stuck INSIDE — body hidden by the inside skeleton, shadow/reticle flagging with it =
|
||
the reported bundle. Camera + reticle + view + `tshd` shadow are all gated on `buildDebugChaseCamera
|
||
= (view_type == insideEntity)` (btl4vid.cpp:297).
|
||
- **Status: could NOT reproduce (2026-07-10) → likely already fixed.** 9 automated 2-node loads PLUS a
|
||
forced death/respawn all came up CLEAN (the respawn completed to external chase; clean backbuffer via
|
||
the new `BT_SHOT` dump). Since debug uninit is a deterministic `0xCDCDCDCD` (would glitch every run),
|
||
the intermittency implies a **race**, and the task #52 respawn fixes (the `LoadMission` re-entry
|
||
killer bug, viewpoint relink, death-latch) plausibly ALREADY closed it. **Left as WATCH** — re-open
|
||
and capture with `BT_SHOT` if it recurs. Tools kept: **`BT_SHOT=<path>`** (per-instance backbuffer
|
||
PNG, off by default, L4VIDEO.cpp) + `scratchpad/hunt53.sh` (N-run divergence hunter).
|
||
- **P6 smoke test:** two instances share a world — console egg → TCP mesh → synchronized start →
|
||
bidirectional entity replication (each renders its own mech + the peer's REPLICANT), 0 crashes.
|
||
- **Movement replication:** A's mech WALKS on B's screen (the replicant tracks the master to ~1.5u via
|
||
dead-reckoning). The authentic mission-start ladder runs (CreatingMission→…→RunningMission via the
|
||
console LAUNCH). SIX bugs fixed to get here (dead-reckoner install, replicant-motion DeadReckon,
|
||
master emission threshold, emission gated on RunningMission, the console-must-LAUNCH fact, replicant
|
||
validity). [T2]
|
||
- **Wire-format bug class found+fixed:** MakeMessages replicate RAW over TCP, so string payload must be
|
||
INLINE (`char[N]` at the binary offsets), not a `const char*` pointer (garbage cross-pod). Check
|
||
EVERY MakeMessage for pointer payloads. [T2]
|
||
|
||
## Debug tooling (`BT_NET_TRACE`, permanent)
|
||
`[net-tx]/[net-rx]` (L4NET), `[net-upd]` (update lookup), `[upd-repl]`, `[ent-exec]` (state ladder).
|
||
Per-instance: `BT_LOG=<file>` + `BT_AFFINITY=<mask>` (CPU pin). Update stream ≈ 60 Hz × 144-byte
|
||
records per moving master. [T2]
|
||
|
||
## Cross-pod combat step 1+2 (task #46, 2026-07-09) [T2 findings]
|
||
**Step 1 — target ANY peer mech: DONE + verified.** A live-mech registry (`BTRegisterMech`/
|
||
`BTDeregisterMech` from the Mech ctor/dtor, btplayer.cpp) collects every Mech — player, dummy,
|
||
AND peer replicants. The mech4 boresight world-pick now walks `BTGetTargetCandidates` (all mechs
|
||
≠ shooter) and picks the CLOSEST the ray strikes, retargeting the whole fire/damage block from
|
||
the solo `gEnemyMech` to the picked `hotTarget` (missile impact + projectile validation
|
||
generalised via `BTIsRegisteredMech`). Verified one-box: instance A correctly enumerates B's
|
||
mech as a live `ReplicantInstance` (inst=4), 20 zones, `ownerID=3`, alive. Solo un-regressed
|
||
(pick→damage→kill chain clean).
|
||
**Step 2 — cross-pod damage: SOLVED + verified end-to-end (task #47, 2026-07-09).** A one-line fix
|
||
(`Mech::Make`) yields a full cross-pod KILL: instance A (host 2) shoots B's mech (host 3) dead over
|
||
the network, B runs the death transition (wreck swap + explosion) on its own screen. [T2]
|
||
|
||
**THE BUG (root cause): B's own MASTER mech was INVALID, so every dispatched network message to it was
|
||
DEFERRED forever.** `Entity::Receive(Event*)` (ENTITY.cpp:165) does `if(!IsValid()) event->Defer();
|
||
return;`. The reconstructed `Mech::Make` (mech.cpp) force-set `ValidFlag` ONLY for replicants (the P6
|
||
bring-up hack for the partial MakeReady/CheckLoad handshake); a locally-created **master** never got
|
||
validated. So A→B TakeDamage arrived, resolved to B's real master mech, Posted, drained to
|
||
`Entity::Receive` — which saw `valid=0` and Deferred it. Handler never ran → 0 damage.
|
||
|
||
**THE FIX:** `Mech::Make` now sets `ValidFlag` for the master too (`if (mech != 0) mech->SetValidFlag();`
|
||
— the reconstructed ctor builds the whole mech synchronously, so it's safe). NOTHING ELSE changed: the
|
||
targeting, the virtual `victim->Dispatch`, the reroute, the wire, the receive, and the id resolution
|
||
were all already correct. Solo un-regressed (the solo enemy was already force-valid via btplayer:839;
|
||
the change only ADDS `ValidFlag`).
|
||
|
||
**Verified full path** (2-node one-box, `BT_MP_FORCE_DMG` on A firing at B's replicant once/sec):
|
||
1. A: `victim->Dispatch(&td)` (VIRTUAL — the real beam path) → `Entity::Dispatch` reads `inst=Replicant`,
|
||
stamps `entityID=3:22` (B's master id), `if(ReplicantInstance) SendMessage(ownerID=3, EntityManagerClientID)`.
|
||
2. Wire: `NetworkManager::Send` (L4NET.CPP:1062) → `send()` to host 3 (online).
|
||
3. B: `ReceiveNetworkPacket` (NTTMGR.cpp:107) → `GetEntityPointer(3:22)` = `entityIndexSocket.Find`
|
||
(HOSTMGR.h:270) → resolves to B's **master mech (classID 3001=0xBB9)** → `Post(EntityManagerEventPriority)`.
|
||
4. B: event drains → `Entity::Receive` (now `valid=1`) → `Mech::TakeDamageMessageHandler` (mech.cpp:584)
|
||
→ invalidZone (−1) cylinder lookup → zone damage. ~36 hits × 12 → B's mech DESTROYED + death transition.
|
||
|
||
**Two prior mis-diagnoses corrected — both were the WRONG messageID.** `Entity::TakeDamageMessageID` is
|
||
**18**, NOT 21 (confirmed at runtime: `td.msgID=18`, so `Simulation::NextMessageID`=3, not 6). Every
|
||
earlier probe filtered `msgID==21`, so it NEVER matched a real
|
||
TakeDamage — the stray `msgID=21` hits it caught were an unrelated message, and correlating their `3:19` /
|
||
`classID 48` against the real `3:22` TakeDamage produced two phantom root causes: (a) the "cross-TU Entity
|
||
layout divergence" (disproven separately — an `offsetof` probe showed `Entity` is IDENTICAL in both TUs:
|
||
`sizeof=444`, `entityID@380 (0x17C)`, `ownerID@388`, `simulationFlags@32`; distinct from the REAL P5
|
||
raw-offset stomps at `this+0x2d4..0x2f0` in `docs/HARD_PROBLEMS.md`), and (b) the "localID drops by hostID
|
||
on the wire" claim. Both are FALSE. The id is correct end-to-end (`3:22` = B's master); nothing on the wire
|
||
is corrupted. Lesson: when a message probe seems to see a wrong id, first confirm the numeric messageID.
|
||
|
||
Retained gated instrument: `[mp-force]` (BT_MP_FORCE_DMG + BT_MP_LOG) — the 2-node cross-pod reproducer,
|
||
off in solo. `[mp-hdlr]` (BT_MP_NET, mech.cpp:591) logs each applied cross-pod hit. 2-node launch recipe +
|
||
`scratchpad/mp_test.sh`: A `-egg MP.EGG -net 1501`, B `-net 1601`, then `python tools/btconsole.py MP.EGG
|
||
127.0.0.1:1501 127.0.0.1:1601` (MP.EGG `[pilots]` = game ports 1502/1602).
|
||
|
||
## Interactive -net aim + drive (task #48, 2026-07-09) [T2]
|
||
Re-measured on a 2-node one-box run. **The prior "aim ray dead / drive dead in -net" claim was STALE — both
|
||
work:** A's aim ray is live (`noRay=0`) and A drives (`BT_AUTODRIVE`/`BT_GOTO` move it).
|
||
|
||
**FIXED — torso-pitch aim ray (gyro-stabilized boresight).** The aim/pick ray was the active RENDER EYE's
|
||
view direction, which (a) inherits the mech BODY pitch — on a slope the body tilts ~8° to conform to terrain
|
||
and the boresight pointed that far DOWN, hitting terrain ~50-100 m short of the enemy (`groundPicks`, never
|
||
`mechPicks`); and (b) in CHASE view (the DEFAULT) is the elevated behind-the-shoulder camera, so the ray
|
||
started over the mech's shoulder. Fix (L4VIDRND `DPLEyeRenderable::Execute`, the `BTSetAimCamera` publish):
|
||
LEVEL the boresight (drop the view-dir pitch, rebuild an upright basis with world +Y) AND anchor its ORIGIN
|
||
at the mech's torso (`myEntity->localToWorld` translation + ~5) instead of the render eye. The guns now fire
|
||
along the mech's horizontal heading from the torso, independent of view mode and terrain tilt. The reticle X
|
||
still carries the torso twist (`BTTwistToReticleX`); reticle Y any elevation. VERIFIED end-to-end: solo,
|
||
enemy 120 m ahead, **both chase AND cockpit** view → `[target] MECH under boresight ... mechPicks=59
|
||
groundPicks=0` → beam → `*** DESTROYED`. Also proved `PickRayHit` resolves a REPLICANT when aimed at it
|
||
(`hit=1` at 757 m in a 2-node run); the replicant `localToWorld` is correct (DeadReckon + `localToWorld=
|
||
localOrigin`, mech4.cpp:1191). [T2]
|
||
|
||
**FIXED — drive-to-range (the automated cross-pod kill now runs end-to-end).** The `BT_GOTO` beeline had
|
||
three separate faults: (1) it was gated behind `if(gBTDrive.forced)` (mech4.cpp), and `forced` was set ONLY
|
||
by `BT_AUTODRIVE` — so `BT_GOTO` alone never drove (chicken-and-egg: the block that would drive was gated on
|
||
the drive being on). Fix: `BT_GOTO` now enables forced mode itself + supplies its own forward throttle (a
|
||
"beeline" must drive, not just steer), cutting throttle inside a stop radius (weapon range for `enemy`, so it
|
||
holds and shoots instead of ramming). (2) The steering used the `gDriveHeading` SCALAR MIRROR (seeded to 0),
|
||
but MP pilots spawn facing a non-zero heading, so the beeline steered the WRONG way. Fix: compute the heading
|
||
error from the mech's ACTUAL forward (`localToWorld`'s -Z axis), signed angle to the target. (3) The goto turn
|
||
was routed through `controlsMapper->turnDemand`, which read 0 in -net — the heading froze and A drove straight
|
||
past B. Fix: apply the goto turn to the orientation integration DIRECTLY (`if(gBTGotoActive) turn=gBTGotoTurn`),
|
||
after the mapper read. **CAUSE FOUND LATER (task #51): turnDemand zeroed because `controlMode` was pointer
|
||
garbage — the `pilotArray[1]` shrunk-span overrun (see [[reconstruction-gotchas]] §5), MP-only because solo's
|
||
overrun wrote 0==BasicMode. Fixed at the root (10-slot array); the direct goto-turn stays (harmless, and it
|
||
skips the 1-frame mapper latency). KEYBOARD turning in MP was restored by the root fix.**
|
||
VERIFIED 2-node: A `BT_GOTO="enemy"` alone (no autodrive) drives `dist 1673→231 m`, holds at range, `mechPicks=59`,
|
||
autofire → **B hdlr=192, DESTROYED** — a fully automated human-style cross-pod kill via the real beam path
|
||
(not the FORCE_DMG hook). Solo un-regressed (plain autodrive + goto both work). `scratchpad/mp_kill_test.sh`;
|
||
`BT_GOTO_LOG` traces the beeline.
|
||
|
||
## Replicant gait animation (task #50, 2026-07-09) — DONE [T2]
|
||
A peer's replicant used to slide as a frozen statue (DeadReckon moved it; nothing animated it). Now the
|
||
replicant block (mech4.cpp, after `DeadReckon`) derives a SIGNED speed demand from the replicated
|
||
velocity — the master publishes `worldLinearVelocity` in every update record (`Mover::WriteUpdateRecord`
|
||
MOVER.cpp:759), the replicant stores it in `updateVelocity.linearMotion` (:712); sign = the forward dot
|
||
against the mech's -Z facing — writes it to `controlsMapper->speedDemand` (the LEG channel's live source)
|
||
and advances the LEG state machine for its JOINT writes only. Travel stays DeadReckon (the returned
|
||
distance is discarded) so position always follows the master; the clip cadence matches the replicated
|
||
speed. ⚠ REPLICANT GAIT-SCALAR PRIMING (same class as the master's per-frame primes, which live in the
|
||
PLAYER-only drive block): `globalTimeScale`/`idleStrideScale` read 0 on a replicant (clip frozen at
|
||
advance-time dt*0, legState engaged but legCycle stuck 0), and `reverseSpeedMax2`@0x7a0 (the run-cycle
|
||
rise-clamp; LoadLocomotionClips does NOT set it) read debug-heap garbage → legCycleSpeed clamped to
|
||
-4.3e8 entering run state 13. Both primed in the replicant block; `legCycleSpeed` itself sane-banded once.
|
||
VERIFIED 2-node: the observer's replicant runs the full lifecycle — stand→walk(5,7)→run(10,12) with
|
||
legCycle 7.5→34 tracking the master's speed, wind-down (8) and back to Standing(0) when the master stops.
|
||
Solo un-regressed. `BT_REPL_LOG` traces pos/vel/legState/legCycle; recipe `scratchpad/mp_gait_test.sh`.
|
||
NOTE: the update-record velocity is currently the master's ACTUAL travel velocity (worldLinearVelocity
|
||
from the leg channel); the binary publishes the BODY channel's smoothed projection (projectedVelocity,
|
||
disasm +0x2a0). Swapping the source is a fidelity refinement DEFERRED — it risks a verified working feed
|
||
for a smoothing nuance. [T3 on that nuance]
|
||
|
||
## Mech-level update records (task #1, 2026-07-11) — DONE [T1 transcription / T2 live]
|
||
|
||
The 9-type Mech record channel is LIVE end-to-end: **writer @004a0c2c** transcribed
|
||
instruction-for-instruction from `reference/decomp/mech_writeupdate_004a0c2c.disasm.txt`, **reader
|
||
@004a1232** rewritten from part_012.c:9576-9692 with every Wword absorber promoted to the NAMED
|
||
engine/port member. Wire sizes verified live (0x14/0x20/0x2c/0x78). Key mechanics:
|
||
|
||
- **Record type == the `updateModel` BIT INDEX** (`Simulation::WriteSimulationUpdate` walks the
|
||
mask, SIMULATE.cpp:302-328; binary twin FUN_0041bd98). Request = `Mech::ForceUpdate(1<<N)`
|
||
(@0x4a4c54: `updateModel |= mask`, `&= 0xfe03` filter when disabled). THREE prior mislabels of
|
||
the same binary fns are retired: `SetInstanceFlags` and `RequestActionFlags` (both @0x4a4c54 —
|
||
+0x18 is `Simulation::updateModel`, NOT entity flags) and `IsNetworkCopy` (@0x49fb54 =
|
||
`IsDisabled`, simulationState 2||9).
|
||
- **`movementMode` == `Simulation::simulationState.currentState`** (binary mech+0x40 =
|
||
StateIndicator@0x2c +0x14; oldState @+0x3c). The port's parallel `int movementMode` member is
|
||
GONE — `MovementMode()/SetMovementMode()` accessors ride the engine StateIndicator, so the state
|
||
(death 9 / limbo 2 / airborne 3,4) replicates in EVERY record header (+0xC) and the replicant
|
||
tracks the master automatically.
|
||
- **Every record tail = the mapper's `speedDemand`** (subsystemArray[0]+0x128) mirrored into
|
||
`bodyTargetSpeed@0x6b4` on both sides — the authentic replicant-gait feed (it was misread as a
|
||
"sequence number"; the type-2 record exists solely to ship it on change). Task #50's
|
||
velocity-derived gait stays as the leg-channel driver meanwhile.
|
||
- **Types**: 0 pose (Mover record + tail; orientation SAVED/RESTORED around the base call — it
|
||
rides ONLY type 4), 1 damage zones (engine), 2 speedDemand, 3 leg-state+stability (write-through
|
||
body dispatch both sides), 4 orientation+angular-velocity resync (euler-encoded, quat
|
||
normalized), 5 knockdown (SetBodyAnimation 0x20 both sides), 6 death, 7 impact (fields only),
|
||
8 airborne/reverse selector. 5/6/7 share the 0x2c heat/throttle/fall-basis payload.
|
||
- **Senders wired byte-exact** (the perf-loop + event map recovered from 27 binary call sites):
|
||
gait transitions `Force(8)` (mech2 — already transcribed under the RequestActionFlags mislabel,
|
||
masks matched the binary exactly), knockdown `Force(1|0x20)` (mech4), death `Force(1|0x40)`
|
||
BEFORE `SetMovementMode(9)` (the disabled filter would mask it after), `Reset` `Force(0x1f)` +
|
||
the binary zero-set (state 0, cycle/target speeds, poseSyncLatch), perf-loop deadbands: position
|
||
→ type 0, orientation deviation → type 4, speedDemand change → type 2, heat-level change → type
|
||
7 (snapshot @0x780). [T3 deadband thresholds — the model record's `UpdatePositionDiffrence` /
|
||
`UpdateTurnVelocityDiffrence` / `UpdateTurnDegreeDiffrence` fields (+0x26..0x28) are the
|
||
authentic constants, not yet streamed to the runtime members +0x768/+0x76c/+0x770.]
|
||
- **VERIFIED 2-node**: types 2/3/4 flow while driving; kill → B emits ONE type-6 (simState=9 in
|
||
the header) → A's replicant flips to MovementMode 9 and its own `UpdateDeathState` runs the
|
||
wreck-sink loop on the OBSERVER's screen (smoke re-arm logged on A; NO double death transition,
|
||
NO replicant VehicleDead) — the death SINK/burial gap (old item 3) is CLOSED. Respawn:
|
||
`Force(0x1f)` burst snaps the replicant to the drop zone + un-wrecks it. Walking replicant
|
||
un-regressed (run states 10→12, legCycle tracking, with type-3 records flowing). Solo clean.
|
||
- Telemetry: `[mrec-tx]/[mrec-rx]` per non-pose record (BT_REPL_LOG). Note the type-1 rx line
|
||
prints a bogus simState (the damage record's own layout at +0xC) — cosmetic.
|
||
- New by-name members: `poseSyncLatch@0x77c` (dead-reckon re-base latch, consumed by
|
||
FUN_004ab1c8), `fallDirection@0x4a8` + `fallScalar@0x4b4` [T4 names], `heatLevelSnapshot@0x780`.
|
||
A TU-local stub type forced the `BTMapperSpeedDemandRaw(void*)` bridge (mech.cpp carries a local
|
||
`struct MechControlsMapper` recon stub — typed cross-TU signatures mangle differently).
|
||
|
||
## Subsystem update-record DIRECTION + the Torso pair (task #57, 2026-07-13) [T0/T1]
|
||
|
||
**Engine semantics [T0 SIMULATE.cpp:270-297]: `WriteUpdateRecord(record, model)` PRODUCES the
|
||
outgoing record from the object (master serialize; base sets `recordLength=sizeof`, stream
|
||
advances by `recordLength` — variable-length records are the mechanism); `ReadUpdateRecord(record)`
|
||
APPLIES the record into the object (replicant).** The names read backwards — do not flip them.
|
||
Base fns in every subsystem vtable: slot 6 = 41bd34 (Read/apply), slot 7 = 41c500 (Write/produce,
|
||
3 args).
|
||
|
||
- **Torso pair:** slot 6 `@004b6a78` = `ReadUpdateRecord` (apply: lastUpdateTime clock stamp +
|
||
twistAtUpdate/twistVelocity/twistRate ← record +0x10/14/18). Slot 7 `@004b6a1c` =
|
||
`WriteUpdateRecord` — **Ghidra missed the function start**; raw-disasm recovery: chains base,
|
||
sets `recordLength=0x1C`, writes currentTwist/twistVelocity/twistRate → +0x10/14/18, snapshots
|
||
`twistAtUpdate = currentTwist`.
|
||
- **The bug this fixed:** the old recon had the APPLY body on the WRITE virtual (and no Write at
|
||
all) — the master consumed its own uninitialized stream buffer (0xCDCDCDCD → twistAtUpdate =
|
||
−4.316e8) and never serialized twist; the replicant MadCat pinned at −140° (the "torso ghost
|
||
twist"). With the pair correct the replicant tracks `targetTwist = twistAtUpdate +
|
||
twistRate·elapsed` cleanly (cur=0 when master still). [T2 live]
|
||
- **Residual (authentic):** the initial full-state snapshot record does NOT carry the torso
|
||
extras; the replicant's blind +0x10 read can pick up 0xCD fill ONCE at spawn. The binary does
|
||
the same read; the twist clamp contains it (on the fixed-torso BLH it pins to ±0.01° —
|
||
invisible). First real twist record overwrites it.
|
||
|
||
## Remaining (P6 phase 4 / Phase 7)
|
||
The pod-LAN config (real IPs, bare-IP pilot entries); update-record velocity sourced from the body-channel
|
||
projection (above). See [[open-questions]]. [T3]
|
||
|
||
## MP-front scout (task #45, 2026-07-09) — the P6 chain SURVIVES the combat/HUD rework [T2]
|
||
Re-ran the one-box smoke test on the current build (world-pick targeting, weapon groups, death
|
||
transition, HUD all landed since P6): console egg → mesh → RunningMission on BOTH instances, 174+
|
||
×144-byte update records EACH side (msgID=6), 2 mech trees per instance, 0 crashes over ~6 min.
|
||
**Gap map to a first playable LAN fight** (in wiring order):
|
||
1. ✅ **Enemy selection — DONE (task #46).** The world-pick used to test only `gEnemyMech` (the solo
|
||
dummy, btplayer.cpp:791); now generalized to the live-mech registry candidate walk
|
||
(`BTGetTargetCandidates`, all mechs != shooter) — see "Cross-pod combat step 1+2" above.
|
||
2. ✅ **Cross-pod damage — DONE (task #47).** TakeDamage dispatched at the REPLICANT reroutes to the
|
||
owning master (verified end-to-end: full cross-pod kill; the master takes real zone damage + runs
|
||
its own death transition; task #42 placed the death dispatch victim-side — MP-correct by
|
||
construction). See "Cross-pod combat step 1+2" above.
|
||
3. **Victim visuals on the shooter's screen** — PARTIALLY resolved (user-observed 2026-07-09): the
|
||
wreck SWAP does appear on the killer's screen, but the death SINK/burial does not (the collapse+
|
||
burial runs only in the owning pod's death transition). Fix path: transcribe the recovered
|
||
Mech-level WriteUpdateRecord death/knockdown record types (5/6 — disasm preserved, task #51).
|
||
3b. **Respawn cycle** (task #52) — the AUTHENTIC cycle is now reconstructed [T1 @004c05c4 +
|
||
engine PLAYER.cpp]: mech death transition (mech4.cpp) dispatches `VehicleDead` (ctor default
|
||
`deathCount = -1` = the death notification) to `GetPlayerLink()` → `BTPlayer::
|
||
VehicleDeadMessageHandler` (@004c05c4 structure): MissionEnding(state 4) skips all; -1 →
|
||
dedup on deathPending, ++deathCount, debit `scenarioRole` life, sever `playerVehicle`
|
||
(the WRECK entity stays), re-post the same message at **now + 5.0 s** (5.0f @004c0830)
|
||
stamped with deathCount; out of lives → the binary posts msgID 0x18 at +10 s (mission
|
||
review; deferred). deathCount ≥ 0 / -2 with a vehicle in hand = acquired (clears
|
||
deathPending); without one → engine base @0042db80 (PLAYER.cpp:214: closest non-"win"
|
||
DropZone → AssignDropZone → 2s re-post probe) → DropZoneReply → CreatePlayerVehicle (a NEW
|
||
mech; `deathCount = 0`) + viewpoint relink (Verify(viewpointEntity==NULL) is compiled out at
|
||
DEBUG_LEVEL 0 — release overwrites, same as the 1995 build). @0049fe0c = roster-wide
|
||
slot-11 DeathShutdown broadcast (the death transition already runs that pass).
|
||
CORRECTIONS to the earlier scouting: BTL4.RES **type 12 = InternalAudioStream** (the engine's
|
||
own resource-type table) — `*int.scp` are internal-AUDIO scripts, NOT per-mech intro scripts;
|
||
and `adrop` (id 1994) is a **type-14 MakeMessageStream** = the map's four DropZone make
|
||
records (0xE0 each: classID 3, origin, facing, name "two"/"three"/…), i.e. the respawn
|
||
infrastructure. **⚠ CORRECTION (2026-07-09): the "blue whirlwind" IS in the game — it is the
|
||
TRANSLOCATION SPHERE, and our port STUBS it.** (My earlier "not a shipped asset" verdict was
|
||
WRONG; it was wrong because I searched only RES resource NAMES + the keyword "whirlwind" — but the
|
||
effect (a) loads `tsphere.bgf` by FILENAME via `d3d_OBJECT::LoadObject`, NOT through the RES table,
|
||
and (b) is called "translocate," not "whirlwind.") The mechanism, fully recovered:
|
||
- **Asset:** `content/VIDEO/GEO/TSPHERE.BGF` (2085-byte low-poly sphere; also in the pod install
|
||
REL410/BT + RP + VWETEST/CYCLE). The exe string table has `tsphere.bgf` / `tsphere`.
|
||
- **Engine class:** `POVTranslocateRenderable` (L4VIDRND.cpp:1749 / .h:638) — a `VideoRenderable`
|
||
(Watcher) that loads `tsphere.bgf` and runs a state machine keyed on a `StateIndicator` "effect
|
||
trigger" (the player's `SimulationState` dial) vs a control state: `IdleState` → (trigger hits
|
||
control state) `InitialCollapseState` (sphere scales `COLLAPSE_START_SCALE 100`→1 over
|
||
`COLLAPSE_TIME 1.3s`, then `SetIsDead(true)`) → `WaitForReincarnateState` (jitters via cos/sin
|
||
`TRANSLATE_LIMIT 2.0`) → (trigger leaves control state = respawn) `ExpandRevealState` (scales
|
||
1→`EXPAND_END_SCALE 150` over `EXPAND_TIME 1.0s`, `SetIsDead(false)`) → IdleState. Rotates
|
||
throughout (`ROTATE_RATE`). I.e. the sphere COLLAPSES onto the mech at death and EXPANDS to
|
||
reveal the reborn mech at respawn — exactly the "blue warp that comes to get you & respawns you."
|
||
- **Wiring (already present in our port!):** `btl4vid.cpp` `MakeEntityRenderables` for a
|
||
`BTPlayerClassID` REPLICANT creates `new BTTranslocationRenderable(entity, Watcher, GetMainView(),
|
||
sim_state=GetAttributePointer(SimulationState), drop_zone=GetAttributePointer("DropZoneLocation"),
|
||
1)` (FUN_00458d2c, alloc 0x40, control state 1); our own POV instead gets `BTPOVStartEndRenderable`
|
||
(the mission fade in/out). So peers watch each other's translocation sphere; your own death is a
|
||
POV fade.
|
||
- **✅ DONE + LOG-VERIFIED (2026-07-09, task #52):** `BTTranslocationRenderable` was a no-op stub
|
||
in `btstubs.cpp`; now reconstructed in `btl4vid.cpp` (state machine + `d3d_OBJECT::LoadObject
|
||
("tsphere.bgf")`), drawn direct from the render loop by `BTDrawTranslocationSpheres` (hooked in
|
||
L4VIDEO.cpp beside `BTDrawBeams`, PASS_ALPHABLEND) — the same direct-draw accommodation the beams/
|
||
reticle use since our VideoComponent tree is partial. Trigger: the LOCAL player's own
|
||
`SimulationState` dial, pulsed `DropZoneAcquired(1)`→`VehicleTranslocated(2)` at respawn (btplayer.cpp
|
||
create branch + a 1.4 s flip timer in `PlayerSimulation`), with the respawn origin written into the
|
||
player's `DropZoneLocation` attribute (the sphere's draw position). Wiring (btl4vid.cpp
|
||
`MakeEntityRenderables`, BTPlayerClassID) originally built the sphere only for REPLICANT players
|
||
(third-party view) + a POV fade for self; extended to build it for the LOCAL player too, since peer
|
||
player-attribute replication (SimulationState/DropZoneLocation) isn't wired (on a replicant both read
|
||
0xCD… uninitialised — confirmed via `BT_TLOC_LOG`). Verified 2-node: on B's respawn the sphere
|
||
COLLAPSES (scale ~100→5) then EXPANDS (→150) at the valid drop-zone origin, deduped to ≤2 active,
|
||
respawn cycle un-regressed, no render errors. Env gate `BT_TLOC_LOG`.
|
||
- **✅ VISUAL DONE + LIVE-VERIFIED (task #52, follow-up):** the on-screen look now matches the
|
||
original cabinet photo (`capture.png`) — a smooth spinning lavender vortex with a bright core. The
|
||
full geometry/material/render authority is now **[[translocation-warp]]**; headlines: tsphere is a
|
||
12-facet BICONE viewed ON-AXIS + spun in place (decomp `FUN_00453dc4` Z-spin, which the WinTesla
|
||
port had stubbed), coloured by the `bintA` cloud through a WIDE lavender ramp, drawn as SKY. The
|
||
defect that hid it for the whole effort was NOT the warp code — it was a general
|
||
**texture-scroll precision-collapse bug** in `L4D3D::SetTextureScrolling` (offset = `scrollDelta ×
|
||
absolute_time` → unbounded → UV precision loss → radial "spokes"), fixed with `fmodf`; that also
|
||
cleans the scrolling beam grit. See [[reconstruction-gotchas]] §13. PEER WARP IS WIRED + VISIBLE
|
||
(`160b78e`): an observer sees a peer's un-wreck warp via the world-anchored `BTStartWarpEffect`
|
||
(mechdmg.cpp:1074, `ReplicantInstance`-gated; `simulationState` rides every record header).
|
||
REMAINING [T3, non-gating]: the peer sphere is anchored to the peer's WORLD position, not the
|
||
peer's authentic `DropZoneLocation` (that attribute isn't replicated) — a fidelity refinement.
|
||
Also confirm the COLLAPSE (death-side) warp fires on every MP death path (force-damage test logged
|
||
EXPAND reliably, COLLAPSE less so).
|
||
NOTE the respawn-cycle SIM path is separate + done: `DropZoneReply` (FUN_004bffd0) → `Mech::Reset`
|
||
(@0049fb74) + the level-2 "translocated" cockpit alarm; `CreatePlayerVehicle` (FUN_004bfcac,
|
||
disassembled — make+link only, matches RP analog). The sphere is a pure RENDER-side watcher on the
|
||
SimulationState dial, independent of that sim path.
|
||
Mech::Reset (@0049fb74) full subsystem-reset sweep is still a bring-up TODO.
|
||
**Three respawn bugs found + fixed on the way (all [T2], 2-node force-damage verified):**
|
||
(i) **death-latch un-latch** — `IsMechDestroyed` tested `graphicAlarm>=9` alone; a later leg hit
|
||
on the wreck rewrites the alarm to 4/3, un-latching → the death transition RE-RAN (double kill,
|
||
double `VehicleDead(-1)`). Fixed to latch on `movementMode 2||9` (see combat-damage.md
|
||
"Death-latch correction"). (ii) **score into severed vehicle** — `BTPlayer::ScoreMessageHandler`
|
||
/ `ScoreInflictedMessageHandler` deref `playerVehicle` unguarded; during the 5s dead window it is
|
||
0 → guard added (apply the award, skip the vehicle response). (iii) **renderer LoadMission
|
||
re-entry** — the KILLER bug: `MakeAndLinkViewpointEntity` (APP.cpp:1265) calls
|
||
`videoRenderer->LoadMission` on EVERY viewpoint-make, so the respawn re-runs
|
||
`DPLReadEnvironment`→`DPLReadINIPage`; its light block `Fail`s ("All lights must be defined on a
|
||
single INI page") because `sceneLightCount` was never reset between reads (ctor-only init). Fixed
|
||
in L4VIDEO.cpp `DPLReadEnvironment`: tear down the prior mission's `sceneLight[]` +
|
||
`sceneLightCount=0` before re-reading (the per-page invariant is intra-read only). This is a
|
||
PORT-layer re-entrancy gap in the 2007 renderer, not BT logic. Caught via cdb `bp ucrtbased!abort`
|
||
— a `Fail`/`Check` is an abort() MessageBox, not an AV, so `sxe av` misses it.
|
||
4. ✅ **Cross-pod beam visuals — DONE (task #51, 2026-07-09).** The keepalive theory needed one
|
||
correction: `FUN_0041c350` = (a) queue the LOCAL deferred beam-effect callback (@0x4bac0c) on the
|
||
app+0x34 manager (our per-weapon render walk plays that role) AND (b) set the subsystem DIRTY bit —
|
||
which maps to the 2007 engine's `updateModel`/`ForceUpdate()`. The REPLICATION rides **subsystem
|
||
update records inside the mech's update message**: the roster walk passes the entity's stream to
|
||
every subsystem's `PerformAndWatch`; `Emitter::WriteUpdateRecord` (@004ba65c, corrected: record
|
||
LENGTH not recordID; rec+0x30 = the TARGET's **EntityID** not a colour) serializes
|
||
firingActive/beamEndpoint/beamFlag/targetID; the engine's `Entity::UpdateMessageHandler` routes
|
||
records by `subsystemID` to `Emitter::ReadUpdateRecord` (@004ba568 — was MIStranscribed as
|
||
TakeDamage; the whole weapon-family slot map was swapped: slot 6=Read, 7=Write, 9=TakeDamage — see
|
||
mechweap.hpp). `ServiceDischarge`/`ContinueDischarge` call `ForceUpdate()` per keepalive tick +
|
||
once at beam end. The render walk was extracted to `Mech::DrawWeaponBeams` (per-mech port cache)
|
||
and runs for REPLICANTS. ⚠ two silent-failure traps fixed: the overrides originally used the
|
||
class's own shadowing `UpdateRecord` typedef as the param type → never overrode the engine virtual
|
||
(base ran, nothing serialized); and `recordLength` must be each level's sizeof or the stream
|
||
framing misparses. VERIFIED 2-node: A fires 57 volleys → 225 records → B applies 225 → draws 414
|
||
replicant beams (PPC blue / laser red from A's replicant's gun ports). Solo un-regressed.
|
||
✅ **The MECH-level records LANDED (task #1, 2026-07-11)** — see the section below; this
|
||
REMAINING note is closed.
|
||
5. ✅ **2-window driving — RESOLVED (tasks #48/#51).** Keyboard MP turning was restored at the root
|
||
(the `pilotArray[1]` shrunk-span overrun fix, task #51); `BT_KEY_NOFOCUS` exists for automated
|
||
harnesses. DEATHS scoring lights via the existing BTPostKillScore MP branch. Respawn is
|
||
reconstructed (task #52 — see item 3b).
|
||
|
||
## Key Relationships
|
||
- Base: [[wintesla-port]] (L4NET). Depends on: [[locomotion]] (update writer), [[combat-damage]]
|
||
(entity lifecycle). Detail: `docs/HARD_PROBLEMS.md` (P6).
|
||
|
||
|
||
## Authentic coupled peer motion — DONE (task #50, 2026-07-14) [T1]
|
||
Decomp-verified (workflows w0odszxro/wh1h5gnmc, 3 make-or-break claims adversarially CONFIRMED; committed c52a1ad + default-promoted). The 1995 peer per-frame path FUN_004ab430 -> FUN_004ab1c8 (IntegrateMotion) drives motion SINGLE-SOURCE:
|
||
- LINEAR position = GAIT. IntegrateMotion advances the BODY gait channel FUN_004a5678 (FUN_004a5028 is DEAD CODE, zero call sites), turns its cycleDistance into velocity `{0,0,-cd/dt}`, rotates by heading, integrates into projectedOrigin.linear@0x260 (part_012.c:14994/14997/15008); localOrigin.linear@0x100 is copied VERBATIM from it (FUN_00408440, part_012.c:15131 -- NOT a lerp). updateVelocity.linear is never used for position.
|
||
- ANGULAR/heading = replicated-velocity slerp (the ONLY thing Mover::DeadReckon-style velocity extrapolation drives): projectedOrigin.angular@0x26c built from updateVelocity.angular@0x2d4 (FUN_004ab188), localOrigin.angular slerped toward it.
|
||
- 0x260 aliasing: "motionDelta@0x260" and "projectedOrigin@0x260" are LITERALLY THE SAME field (base Mover::projectedOrigin, Origin 0x1c); "worldPose@0x26c" is its quaternion half. Our reconstruction's shadow names hid this and drove the false velocity-vs-gait "contradiction".
|
||
- Re-anchor: motionEventVector@0x598 = updateOrigin - localOrigin captured on poseSyncLatch, DECAYED into localOrigin over ~_DAT_004ab9cc (~0.2s) -- no snap. Zeroed in idle states.
|
||
- MASTER + PEER run the SAME predictor. The master's SEND-mirror (FUN_004a9b5c @0x4aab9c) advances projectedOrigin by IntegrateMotion(mj=0) fed the LAST-SENT bodyTargetSpeed, then deadbands |localOrigin-projectedOrigin|^2 vs UpdatePositionDiffrence@0x768. A gait-driven peer REQUIRES this gait mirror (a constant-velocity mirror under-sends -> tug-of-war, measured ratio 1.86).
|
||
- T4 CLOSED: both leg(0x65c) and body(0x6bc) animators are AnimationInstances of the SAME JointedMover/JointSubsystem (JMOVER.cpp:1382) -- either poses the WHOLE skeleton. Our port keeps the peer on the LEG channel (body unbound on the peer); faithful functional equivalent.
|
||
|
||
RECONSTRUCTION STATE: coupled path is DEFAULT ON (mech4.cpp: s_drPos gait-coupled, s_gaitMirror/Send). Reverts: BT_DR_POS=1 (peer velocity), BT_NO_MASTER_GAITMIRROR (master const-vel mirror). Measured: single-source coupling backward-steps 0.1% (vs the two-source split's churn), position ratio 1.043. RESIDUAL (follow-up): occasional ~2.9u snap from the leg(peer)-vs-body(mirror) channel mismatch -- to close, run the master mirror on a leg-channel prediction fed last-sent speed, matching the peer's poser. Also open: exact _DAT_004ab9cc decay constant; whether IntegrateMotion's 2-stage angular integrate is intended.
|
||
|
||
|
||
## Peer motion: the "random shakiness" is single-box packet jitter, NOT the game (task #50, 2026-07-15) [T2]
|
||
After the coupled body-channel peer landed (96a896a + turn-step f094d78 + cadence-mirror 23f1532), residual peer shakiness on accel/decel was RANDOM -- sometimes perfect, sometimes shaky. Root cause is the TEST RIG, proven with BT_RXJIT (record inter-arrival ms on the peer): two Debug btl4 nodes on ONE box contend for CPU, so Windows BATCHES their TCP delivery -- update records arrive in bursts (min ~0ms back-to-back, max 56-226ms gaps, burstiness max/avg 3-7x) instead of an even ~17ms. A peer dead-reckons across the long gaps then snaps when a record lands -> random shake. Pinning each node to a DISJOINT core set (ProcessorAffinity 0x00F / 0x3C0) restored even ~17ms delivery (burstiness ~1.0) and the shakiness vanished (user-confirmed). REAL pods are dedicated machines with no contention -- they never see this. DO NOT add an interpolation/jitter buffer or other un-authentic netcode to mask a single-box artifact. Use tools/mp_launch.sh (bakes in the affinity) for all 2-node tests. Diagnostic env: BT_RXJIT (arrival jitter), BT_SLIDE ([slide]/[mslide] slide-in-stand), BT_GAITEV, BT_MIRDIV, BT_NO_MIRROR_CAD / BT_PEER_LEGCH (revert the coupled-peer fixes). |