# ALARM.HPP — reconstruction notes

**Status: RECONSTRUCTED, compile-verified under BC4.52. First of the 3 missing
Mech embedded-helper classes ([[MECH-LAYOUT]] step 1).**

`AlarmIndicator` — the multi-level status indicator the Mech carries four of
(masterAlarm 33 levels, heatAlarm 3, stabilityAlarm 2, statusAlarm 33). Absent
from the 4.10 archive (no ALARM/STATE variant survives it); reconstructed from
the shipped binary + the surviving StateIndicator source.

## Evidence

- Ctor decomp `FUN_0041b9ec(this, count)` (BT411 reference/decomp part_002.c):
  base ctor, own vtable `&PTR_FUN_004e3440`, three watcher sockets initialised at
  +6/+0xb/+0x10 via `FUN_0041c42c(_, 0)`, then `this[3]=this[4]=this[5]=count`.
- The surviving `StateIndicator::StateIndicator(unsigned max_states)` (CODE/RP/
  MUNGA/SIMULATE.CPP:62) is **byte-for-byte identical**: `audioWatcherSocket(NULL),
  videoWatcherSocket(NULL), gaugeWatcherSocket(NULL)` then `stateCount = oldState
  = currentState = max_states`.

The only difference is the vtable ⇒ AlarmIndicator is a StateIndicator **subclass**
(same Node + 3 state words + 3 SChainOf watcher-socket layout, adds no data). A
derived class naturally gets its own vtable, reproducing `PTR_FUN_004e3440`.

## API

The Mech drives the alarms with `SetLevel(unsigned)` / `GetLevel()` (and reads
`GetLevelCount()`). These map to StateIndicator's `SetState` / `GetState` /
`stateCount` — a level IS a state, so a level change notifies the audio/video/
gauge watchers exactly as SetState does. (BT411's `ReconAlarm` proxy exposed a
raw `level` member; that was a proxy artifact — the real class stores it as
`currentState`.)

## Placement

The 1995 source filename for AlarmIndicator is unknown (BT411 handled it via the
mechrecon.hpp proxy; nothing survives in CODE). Filed as MUNGA/ALARM.HPP; the
Mech includes it. StateIndicator's out-of-line methods live in SIMULATE.CPP
(already in munga.lib), so no new .CPP is needed — AlarmIndicator is header-only.