GRP)¶

Formation and flight/group management: WNG_* manages aircraft wings (a leader plus up to 9 wingmen), GRP_* the byte-identical twin for ground/naval groups. This is the executor the AI interpreter's wm_* commands drive. 0x45E460–0x45FEC0.

Provenance: Ghidra static analysis of the game executable with FA.SMS symbols applied; recorded in the symbol database and applied to the Ghidra project. FA.SMS exported the full GRP API but only part of WNG; every unnamed WNG function is the exact GRP twin (with GRP→WNG), which is how all 15 recovered names are pinned. Progress: reconstruction matrix. Markers follow spec-authoring.md: confirmed · inferred · unknown.

Data model¶

A wing is _wingIds[wing*10 + slot] (ushort ids; slot 0 = leader, 1–9 = wingmen) with _wingSizes[wing] the count — up to 10 wings, 10 groups. GRP is the same on _groupIds/_groupSizes. There are 8 formation types (_fTypeOffsets, 8×10 slot offsets; _wmFormType selects). The formation-command block (_wmFormControl/_wmFormType/ _wmFormSpacingH/_wmFormSpacingV, plus the shared target) is the control surface both the AI interpreter and multiplayer messages write.

Commands: AI interpreter → WNG/GRP¶

The Chuck Talk AI interpreter's wm_ opcodes map 1:1 onto the formation surface: CTDo_wm_hspacing/vspacing/formation/control set it, and CTEval_wm_*_is read it back. Execution reaches WNG/GRP two ways — direct calls on the current object (_GVEventProc → GRPSetType/SetControl/…), or via _MSGSend wingman messages (0x8001/0x8002) whose subcode dispatch in _PLANEEventProc calls the WNG setters (7=SpacingH, 8=SpacingV, 9=Type, 10=Control, 0x0B=attack, 0x0C/0x0D=engage, 0x11=cover-me). WNGSendWM(' ', target) fans an attack order out to all qualifying wingmen.

Wingman commands: the AI interpreter and multiplayer messages write the shared formation-command block; WNGFormationMove positions each wingman relative to the live leader.

Formation-keeping¶

WNGFormationMove indexes slot + formType*10 into _fTypeOffsets for a (dx,dy,dz) unit vector; the target point = (dx·spacingH + jitterX, dy·spacingV + jitterY, dz·spacingH + jitterZ) relative to the live leader (WNGLeader returns the first living member, so formation survives leader loss), then CreateMove issues the move order. Jitter is re-rolled on an interval for natural drift.

Functions¶

Full record: db/symbols/wingman.csv.

VA	Symbol	Role
`0x45E460`	`WNGInit`	zero all wing arrays and formation scalars
`0x45E490`	`WNGAdd`	add the current object to a wing slot
`0x45E710`	`WNGPart`	find id → (wing, slot); leader/wingman test
`0x45E630`	`WNGLeader`	first live member of a wing
`0x45E6E0`	`WNGWingmen`	the wingmen list (slots 1..n)
`0x45E970`	`WNGFormationMove`	position a wingman in formation vs the leader
`0x45ED90`	`WNGSendWM`	dispatch a wingman-message opcode (fan out orders)
`0x45EB30`	`WNGSetType`	set the formation type
`0x45EAC0`	`WNGSetControl`	set the formation control level
`0x45EBF0`	`WNGSetStateTarget`	enter a state + set the shared target
`0x45F190`	`GRPInit`	ground/naval-group twin of `WNGInit`
`0x45F1C0`	`GRPAdd`	group twin of `WNGAdd`
`0x45F440`	`GRPPart`	group twin of `WNGPart`
`0x45FC50`	`GRPAttackingObj`	count group members attacking a target

Open Questions¶

1. `_wmFormControl` semantics¶

Set to 1 on Add and clamped in SetControl with a two-sided comparison; WNGSendWM early-outs when it is > 1. Whether it is a boolean "hold formation", a member count, or a tightness level needs the CT wm_control argument range — a bench (re-gameplay) check.

Status: open — re-gameplay (#56).

ai-interpreter.md — the Chuck Talk wm_* opcodes that drive this.
objects.md — the entity/message system carrying wingman commands.
physics.md — CreateMove / the flight model that executes formation moves.