# HEAT.CPP / POWERSUB.CPP — the power/heat wave (Phase 5.3.10, 2026-07-21)

The mech's thermal + electrical economy is LIVE: weapons dump firing heat into
their own sinks, the sinks conduct through the Condenser bank into the central
HeatSink, temperatures drive the degradation/failure alarms, and every powered
subsystem tracks its generator through the electrical state machine.

## The heat topology (wire-verified on TEST.EGG)

`linkedSinkIndex` (the previously-missing HeatSink resource int — see below)
wires the authored conduction graph at construction:

    weapons / equipment  ->  Condenser1..6 (slots 4-9)  ->  central HeatSink (slot 2)
    GeneratorA..D (10-13) ->  Condensers
    Reservoir (3)         ->  central HeatSink

Authored values match the BT411 calibration audit EXACTLY: central bank mass
1.39e6, PPC's own sink 174000, thresholds 77 start / 1000 degradation / 2000
failure, PPC conductance 86800.  (The central sink's own `linkedSinkIdx=5` is a
FORWARD reference — Condenser2 isn't constructed yet at slot 2's ctor — so its
drain is unwired; a post-walk fixup is a small future item.  Everything drains
INTO it fine.)

## Reconstructed

- **HeatSink::HeatSinkSimulation** (@004ad924): absorb pendingHeat → T =
  E/mass → UpdateHeatLoad (15-sample filter) → ConductHeat → alarm thresholds.
  Installed by the HeatSink ctor (derived classes override and chain it).
- **ConductHeat / ComputeHeatFlow** (@004ad8ac/@004ad9ec): the two-body
  equilibrium relaxation — `(T·massScale − (E_other+pending+E_own)/denom)·tau·
  (1−exp(−dt·conductance·(coolant/capacity)·flowScale/denom))`.  Verified:
  flow == 0 exactly at uniform temperature; a fired PPC bleeds ~170K units/step
  into Condenser4.
- **PoweredSubsystem ctor + PoweredSubsystemSimulation** (@004b0f74/@004b0bd0):
  resolves `voltageSourceIndex` from the roster (GeneratorA-D — wire-verified),
  attaches the tap (`Generator::TapVoltageSource`, −1 when full), and runs the
  electrical FSM (Starting=0 / NoVoltage=1 / Shorted=2 / GeneratorOff=3 /
  Ready=4) watching the generator state.  Deferred: the AutoConnect
  replacement-generator hunt (needs the status flags / damage wave).
- **Generator::GeneratorSimulation** (PARTIAL): heat step + start/short-recovery
  timers; the load model (voltage sag, I²R self-heat feeding the charge
  integration) joins the electrical-charge wave (TrackSeekVoltage).
- **Sensor::SensorSimulation** upgraded to the authentic gating (@004b1c4c):
  power step first, radar = 1 − damage, electrical-Ready gate (badVoltage),
  heat-state switch (Degradation ×0.5, Failure → 0).  Verified: voltState=4,
  radar 100% on the healthy mech.
- Weapons: Emitter/Projectile sims run the power step at their head; the
  Loading recharge is gated on electrical Ready (authentic @4bbdf5); FireWeapon
  dumps the firing heat.

## Heat units (1e7-native) — TWO authoring conventions

The heat chain is 1e7-unit-native (BT411 audit).  The stream stores
`heatCostToFire` in TWO conventions:
- **Energy weapons: small units** (PPC = 11) — the ×1e7 comes from the energy
  closed form ((1−dF)·E ≈ heatCost·1e7 at full charge).  Our partial multiplies
  by 1e7 pending the charge model.
- **Ballistics: native units** (SRM6 = 5.06e7) — dumped RAW.  (Double-scaling
  this to 5e14 was the runaway-temperature bug during bring-up.)
Both land ~+640K on the weapon's own sink — the consistent design magnitude.

## The resource-alignment resolution (wire-verified, closes the +3 mystery)

The raw-stream dumps pinned the FULL ancestry alignment:
- `HeatSink__SubsystemResource.linkedSinkIndex` — THE missing int that shifted
  every descendant block +1 (PoweredSubsystem's voltageSourceIndex previously
  read the linked-sink index — hence "power sources" appearing to be
  Condensers).
- The MechWeapon pip tail is `pipPosition(int) + pipColor(3 floats) +
  pipExtendedRange(int)` (+2) — matches BT411's verified overlay exactly.
- +1 +2 = the +3 the interim ProjectileWeapon pad compensated; the pad is gone.
- True bhk1 reads: PPC recharge **5.0 s** (not the misaligned 1.0), discharge
  0.99 s, range 900, damage 12, heatCost 11, pipColor (0,0,1); SRM6 recharge
  5 s, range 800, salvo damage 35, missileCount 6.

## VERIFIED (BT_FORCE_FIRE + BT_POWER_LOG)

PPC: 77° → fires → ~709° → relaxes to 441° across its 5 s reload → sustained
fire climbs the residual 441 → 674 → 838 → 960 — brushing the 1000° degradation
threshold: the authentic fire-discipline game.  SRM salvos spike +641K and
cross degradation after three.  Condensers absorb and pass to the central
bank.  Neutral run: sensor Ready/100%, mech holds, zero Fail.

## Heat consequences (Phase 5.3.11, 2026-07-22)

The weapon-side consequences are wired and VERIFIED under sustained fire:

- **Ballistic gate 1** (@4bbd36): weapon destroyed-state or its own sink at
  FailureHeat pins full recoil + the unavailable alarm (the NoAmmo roach-motel
  re-asserts).  (Mech-disabled half joins the damage wave.)
- **CheckForJam** (@4bbfcc): `p = 0.41·T/failT` clamped [minJamChance, 1.0],
  rolled per granted shot against the MUNGA uniform `Random`.  Interim gate:
  heat-degraded only (stands in for the deferred `LiveFireEnabled` novice
  switch AND the trivially-true `heatLoad>0` early-out — the exact spurious-
  cold-jam trap the BT411 port documented).  Verified: SRM6s jam at
  T≈1200-1320 (24%+ rolls past the 1000° threshold), stay jammed.
- **Emitter hard gate** (@4baab9): FailureHeat drops the beam state + charge
  each frame; SELF-RECOVERING — conduction cools the sink below 2000° and the
  weapon resumes from Loading.  Verified: the PPC settles into an emergent
  thermal duty cycle (fire at ~1930° → spike 2562° → shutdown → cool → refire);
  the lasers oscillate around ~2200°.

## Still deferred

UpdateCoolant / BalanceCoolant (coolant depletion + venting), the
HeatModelOff / LiveFireEnabled experience gates (novice mode), the electrical
charge model (TrackSeekVoltage / voltage sag / I²R), the mech-disabled halves
of the weapon gates (damage wave), the central sink's forward-linked drain,
Condenser MoveValve handling, jam recovery via ResetToInitialState (mission
reset path).