# SENSOR.CPP — reconstruction notes

Built against the surviving 4.10 CODE header `CODE/BT/BT/SENSOR.HPP` (Sensor :
PoweredSubsystem). Attributes RadarPercent / SelfTest / BadVoltage chain
`PoweredSubsystem::NextAttributeID`.

## Reconstructed

- Ctor: primes radarPercent=1, selfTest=False, badVoltage=False and installs
  `Sensor::SensorSimulation` as the per-frame Performance (unless the owner is a
  replicant copy, which is console-driven).
- `TestClass` / `TestInstance` / `ResetToInitialState` / the shared-data statics.

## PARTIAL: Sensor::SensorSimulation (per-frame)

The authentic `SensorSimulation` (BT411 @004b1c4c) does, each frame:
1. `PoweredSubsystem::PoweredSubsystemSimulation(time_slice)` (power/voltage tick),
2. `radarPercent = RadarBaseline - GetSubsystemDamageLevel()`,
3. gate on the electrical Ready state (`badVoltage`, zeroes radar if not Ready),
4. gate on the heat state — Normal / Degradation (`radar *= 0.5`) / Failure
   (radar 0, selfTest off).

Steps 1/3/4 depend on the **power/heat per-frame simulation chain that is not
yet reconstructed** — `PoweredSubsystem::PoweredSubsystemSimulation`,
`Generator::GeneratorSimulation`, `HeatSink::HeatSinkSimulation`,
`HeatWatcher::WatchSimulation`, `PowerWatcher::Simulation` are all staged
`Fail`. None of those are installed as Performances yet (only Sensor installs
one), so the roster otherwise ticks `DoNothingOnce`.

Until the power/heat wave, `SensorSimulation` runs the one reconstructed input
(step 2, using `MechSubsystem::GetSubsystemDamageLevel`, clamped ≥ 0) and
reports the sensor healthy (selfTest=True, badVoltage=False). This is a
**deliberately safe partial**: it keeps the engine's `Entity::PerformAndWatch`
roster-tick path alive (it must not `Fail`, or the whole per-frame simulation
aborts the frame the mission reaches RunningMission) while producing a real
radar-capability value. Deepen it with the power/heat simulation wave.

A gated one-shot (`BT_MECH_LOG`) logs the first Sensor frame — the marker that
the entity/roster simulation has engaged (RunningMission).