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Multiplayer Chat

The human-to-human text channel in multiplayer: a small edit-line handler (CHAT*) that captures keystrokes, targets a recipient set (all / side / wing / squadron), supports 12 preset macros loaded from a file, and sends each line over the same MSGSend path the AI radio uses.

Provenance: Ghidra static analysis of the game executable with FA.SMS symbols applied; recorded in the symbol database and applied to the Ghidra project. Progress: reconstruction matrix. Markers follow spec-authoring.md: confirmed · inferred · unknown.

The chat handler (#493)

CHATInit (0x413120) resets the edit state and loads the CHATMAC macro resource (0x4EE2A0) into 12 preset slots. Each macro line is parsed [\recipient\]text[\soundfile] into three parallel arrays: a destination-mode index (0x522940), a text string (0x522970, stride 0x33), and an optional .5K sound name (0x522720, stride 0x29). confirmed

CHATKey (0x4133C0) is the whole interactive surface — it returns 0 when it consumes a key, otherwise passes it through to the game: confirmed

  • Open an edit line — ` / ~ / Alt+Enter start editing with a target mode of all (0), side (1/2), wing (3), or squadron (4). CanChatMode gates which modes are usable (side/wing require sides to have been chosen; in-flight vs pre-mission is the _curScreen == 0x10 test).
  • While editing — printable keys append to the buffer, Tab / Shift+Tab cycle the target mode, F1–F12 fire a macro (its text + sound go to the mode's recipients immediately), Enter sends the typed line, Esc / ` cancels.
  • Send — the line goes to every reachable player via MSGSend(kind 0x24), addressed 0x8003 + station. ChatCanReach decides who is in range for the chosen mode by testing same-side / same-wing / same-squadron over _objControlledBy and _humanChoseSide.

CHATGetEditLine formats the in-progress line ("SEND TO ALL: text_" with a blinking cursor) for the HUD overlay, and CHATFixKeyarray — called from the keyboard hook (KEYEvent) — forces the flight-control keys in _keyarray to released while a line is being edited, so typing a message never also flies the plane. CHATEndMission resets the channel between missions. confirmed

Chat: CHATKey captures the edit line and target mode, expands F-key macros from CHATMAC, and sends each line through MSGSend to the reachable players; CHATFixKeyarray keeps typing from flying the plane.

Functions

Full record: db/symbols/chat.csv.

VA Symbol Role
0x413120 CHATInit reset state + load the CHATMAC macro slots
0x4133C0 CHATKey the edit-line / macro / send key handler
0x413960 ChatCanReach can chat mode M reach player P (side/wing/squadron)
0x413B60 CHATGetEditLine format the in-progress line for the HUD
0x413C20 CHATFixKeyarray suppress flight keys while typing

Open Questions

1. The CHATMAC macro-file format

CHATInit parses CHATMAC as [\recipient\]text[\soundfile] lines into 12 slots, but the retail file itself has not been examined. Reading it (an asset task, needs FX_FA_ROOT) would confirm the recipient tokens (SEND TO ALL, …) and give a worked example for a format note.

Status: open — re-asset (dump the retail CHATMAC and cross-check the parse).

  • radio.md — the MSGSend queue chat sends through.
  • input.md — the key-code space and KEYEvent, which calls CHATFixKeyarray.
  • network.md — the multiplayer session that populates _humanChoseSide.