Engine lifecycles

State machines and execution sequences in the LBA2 engine. Each section lists states with their code-level constants, the typical sequence, and where the logic lives.

Truth hierarchy: code > this document > external sources.

Main loop frame order

Each game frame executes these steps in order. Defined in MainLoop().

Step	Function	What it does
1	MyGetInput() + ManageTime()	Read player input and advance timer
2	DoDir(i) per object	Compute movement direction
3	DoTrack(i) per object	Execute track script (pathing)
4	PtrDoAnim(i) per object	Advance animations
5	CheckZoneSce(i) per object	Test zone triggers
6	DoLife(i) per object	Execute life script (behavior AI)
7	AffScene()	Render the scene

Code: SOURCES/PERSO.CPP (MainLoop), SOURCES/GERETRAK.CPP (DoTrack), SOURCES/GERELIFE.CPP (DoLife), SOURCES/OBJECT.CPP (CheckZoneSce)

Scene (cube) loading

Triggered by ChangeCube() when the hero enters a zone-type-0 trigger or a life script executes LM_CHANGE_CUBE.

Phase	What happens
1	Unload current scene objects and zones
2	Load collision grid (BufCube[]) for the new cube
3	Load objects into ListObjet[] (up to MAX_OBJETS=100)
4	Load zones into ListZone[] (up to MAX_ZONES=255)
5	Set CubeMode (0=interior, 1=exterior)
6	Initialize camera position

Code: SOURCES/OBJECT.CPP (ChangeCube), SOURCES/GRILLE.CPP (grid loading)

Object lifecycle

Objects are loaded when a scene starts and can be killed during gameplay.

State	Meaning	Terminal?
Alive	Object exists, scripts run each frame	No
Dead	OBJ_DEAD bit set in WorkFlags	Yes

Happy path: Alive (scripts running) -> LM_KILL_OBJ or LM_SUICIDE -> Dead

Transitions:

• LM_KILL_OBJ (opcode 37): another object's life script kills this object
• LM_SUICIDE (opcode 38): object kills itself
• Both set OBJ_DEAD (bit 5) in WorkFlags

Code:

• Constants: SOURCES/COMMON.H (OBJ_DEAD, LM_KILL_OBJ, LM_SUICIDE)
• Transitions: SOURCES/GERELIFE.CPP (DoLife opcode handlers)

Hero behavior modes

The hero's Comportement determines movement style, available actions, and combat behavior. Changed by player input or by LM_COMPORTEMENT_HERO in life scripts.

Modes 0–3 are player-switchable; 4–13 are context-triggered. Full enum (constants and meanings): GLOSSARY.md#comportement-hero-behavior-modes.

Player-switchable core modes: Normal <-> Athletic <-> Aggressive <-> Stealth (via COMPORTEMENT input or NORMAL/SPORTIF/AGRESSIF/DISCRET direct inputs).

Other modes are context-triggered by life scripts (LM_COMPORTEMENT_HERO, opcode 30).

Code:

• Constants: SOURCES/COMMON.H (C_NORMAL through C_SKELETON)
• Transitions: SOURCES/PERSO.CPP, SOURCES/GERELIFE.CPP

Animation state

Each object has an animation that progresses through frames each tick.

State	Meaning	Terminal?
Playing	LastFrame < NbFrames, NEW_FRAME set each tick	No
Ended	ANIM_END (bit 2) set in WorkFlags	Yes (until new anim)

Happy path: Anim set (via LM_ANIM / LM_ANIM_OBJ) -> Playing -> ANIM_END

Scripts typically check ANIM_END before assigning the next animation. Looping animations restart automatically without setting ANIM_END.

Code:

• State: T_OBJ_3D.LastFrame, T_OBJ_3D.NbFrames in LIB386/H/OBJECT/AFF_OBJ.H
• Flags: ANIM_END, NEW_FRAME in SOURCES/COMMON.H
• Anim engine: LIB386/ANIM/

Related docs

This is the temporal view of the engine. Two companion maps give the other axes:

• ARCHITECTURE_GLOBALS.md — structure: the ~200 globals grouped into eight owning domains, with the shared-bus offenders. The pivots in the state machines above (ListObjet, CubeMode, Comportement) are its worst offenders.
• ENGINE_GAME_SEAM.md — layer: engine vs game vs platform, from a three-way diff against the LBA1 source. The main-loop steps DoTrack (3) and DoLife (6) are where the engine crosses into the game's Life/Track scripts.