LightningScript

LightningScript Reference

LightningScript is the AngelTech Engine's scripting language for defining entity behaviors, world interactions, and dynamic events. It replaces the legacy ParasiteScript system.

Files use the .ozls extension.

Entity Definition Format (.ozls)

entity "<name>" : <type> {
    mesh = "<path>"
    texture = "<path>"
    icon = "<path>"

    stats {
        <name> = <value>
        vec3 <name> = (<x>, <y>, <z>)
    }

    variants {
        "<variantName>" { mesh_override = "<path>"  texture_override = "<path>" }
    }

    actions {
        on_<action> {
            <script lines>
        }
    }
}

Types

Type	Purpose
weapon	Ranged/melee weapon (hotbar, projectile dispatch)
armor / upgrade	Equipment items
consumable	Consumables (use via hotbar on_use)
pickup	World pickup (item_id/respawn_time stats)
skyzone	Zone volume with env/fog/skybox/zone actions
pawn	NPC hook-carrier (FSM actions: on_patrol/on_chase/on_return/on_death)
projectile	Reserved (no runtime consumer yet)

Stats Block

Defines runtime numeric properties:

stats {
    damage = 25.0
    magazine = 12
    vec3 color = (1.0, 0.2, 0.1)
}

Weapon-Specific Stats

Stat	Type	Ranged Default	Melee Default	Description
damage	float	10	10	Damage per projectile or melee hit
fire_rate	float	0.25	—	Seconds between shots (ranged)
swing_speed	float	—	0.25	Seconds between swings (melee)
magazine	float	none	—	Ammo capacity per magazine (ranged only)
reload_time	float	2.0	—	Seconds to complete a reload
projectile_speed	float	20	—	Projectile travel speed in units/sec
projectile_lifetime	float	2.0	—	Projectile lifespan in seconds (legacy key lifetime also accepted)
projectile_count	float	1	—	Number of projectiles per shot
spread	float	0	—	Random spread angle in degrees
reach	float	—	3.0	Melee attack range in units

Sound Stats

Sound is authored per-entity in the same stats block. Values are asset paths;
they resolve def-relative first, then via the package loader, so a .wav
inside a .ozsnd works exactly like a loose file.

Stat	Type	Applies To	Default	Description
fire_sound	string	ranged weapon	Audio/Sounds/Guns/machgf3b.wav	One-shot per projectile fired
swing_sound	string	melee weapon	(silent)	One-shot per melee swing
hit_sound	string	melee weapon	(silent)	Melee connect that is not blocked by geometry
reload_sound	string	any weapon	(silent)	Once per reload (manual and auto)
equip_sound	string	any weapon	Audio/Sounds/Entities/weapload.wav	Selecting the weapon in the hotbar
fire_volume / swing_volume / hit_volume / reload_volume / equip_volume	float	matching key	1.0	Linear gain
fire_pitch / swing_pitch / hit_pitch	float	matching key	1.0	Playback rate (0.85 = deeper)

Player sound lives on Player.ozls (GameData/Tex/Global/Models/), read off the
auto-spawned Player entity: jump_sound, land_sound, walk_sound,
run_sound, hurt_sound, death_sound, each with a _volume.

stats {
    fire_sound = GameData/Audio/Sounds/Guns/machgf3b.wav
    fire_volume = 0.9
    fire_pitch = 0.85
}

Authoring rules — these fail silently if broken:

• No quotes, no spaces. A stats string value is stored verbatim; the
  parser does not strip quotes, and it stops at the first space. Write
  fire_sound = a/b.wav, never fire_sound = "my gun.wav". A space truncates
  the path and it will simply never resolve.
• Deliberate asymmetry: fire_sound and equip_sound fall back to a
  global default, so an unauthored weapon still shoots. swing_sound,
  hit_sound, reload_sound and land_sound have no fallback — an
  unauthored key is simply silent, because there is no honest generic clip for
  "a blade connected" and borrowing one would make every swing in every level
  sound identical.
• hit_sound fires only on a connect that cleared geometry. A swing that stops
  at a wall runs no on_hit and makes no connect sound.
• run_sound is chosen off the sprint key while the player is moving;
  walk_sound otherwise. Both are loops.

All of these are editable from the AngelEd Property Window — see
Editor-Usage.md.

Action Blocks

Scripts attached to specific events:

Action	Trigger
on_use	Player selects the entity from hotbar and presses E/Enter
on_equip	Entity is equipped
on_unequip	Entity is unequipped
on_fire	Ranged weapon fired (before projectile spawn)
on_swing	Melee weapon swung (before range check)
on_hit	Melee swing connects with a target
on_reload	Weapon reload triggered (auto or manual via R key)
on_collect	Entity is picked up
on_enter	Player enters a zone/skyzone volume
on_exit	Player exits a zone/skyzone volume
on_tick	Called every frame while active
on_patrol / on_chase / on_return / on_death	Pawn FSM state transitions (requires a pawn-named .ozls, e.g. Walker.ozls)

Opcodes

Variable Operations

Opcode	Syntax	Description
var	var x = 5	Declare int (no decimal) or float (has decimal)
$	$x = 42	Assign to runtime variable (creates if not exists)
$ +=	$x += 5	Add and assign
$ -=	$x -= 3	Subtract and assign
$ *=	$x *= 2	Multiply and assign
$ /=	$x /= 2	Divide and assign
RHS arithmetic	$x = $x - 1	Assignments support one binary op (+ - * /) with variables/numbers

Variables are referenced in conditions with $ prefix (e.g., $health > 0).
$flag<idx> (e.g. $flag0) reads the instance's toggle flags set by wtflag/toggle_flag.

Control Flow

Opcode	Syntax	Description
if / else / endif	if ($x == 0) ... endif	Conditional execution (brace style if (...) { ... } also supported)
goto / jump	goto label_name	Jump to a label
stop / end	stop	Halt script execution
say	say "hello"	Print to log
set_cooldown	set_cooldown 1.5	Set cooldown timer in seconds

Flags

Opcode	Syntax	Description
wtflag	wtflag idx val	Write toggle flag (0-63)
rtflag	rtflag idx	Read flag value into $result
toggle_flag	toggle_flag idx	Flip a toggle flag (0-63)

Hotbar/equipment instance flags are persisted in save games (flags= section). Zone-instance flags are session-only.

World Interaction

Opcode	Syntax	Description
set_fog	set_fog r g b density	Set fog color and density
restore_fog	restore_fog	Restore fog to world default
set_ambient	set_ambient r g b	Set ambient light color
restore_ambient	restore_ambient	Restore default ambient
set_skybox	set_skybox "name"	Set skybox by name
restore_skybox	restore_skybox	Restore default skybox
play_sound	play_sound "path"	Queue sound playback (package-aware: resolves .ozsnd via SoundManager::PlayScriptSound)
msg	msg "text"	On-screen text message
heal / damage	heal 25	Immediate player health delta
playerstat	playerstat health -= 5	Deferred write to a player stat
consume	consume	Mark consumable as used (removes from hotbar)
spawn_pawn	spawn_pawn "Walker" x y z	Spawn an NPC
spawn_pickup	spawn_pickup "Coin" x y z [respawn]	Spawn a pickup

Gameplay / event opcodes (Phase 1)

These queue a deferred ScriptCommand the host applies after the action body
runs. Engine-generic ones are applied by LightningEntityManager; the ones that
need the camera or world loader are drained by Core.hpp.

Opcode	Syntax	Effect
emit_event	emit_event "zone.enter" [int]	Publish an EventBus event (topic, optional int). The bridge runs on_<topic> on the def named by the event's s0.
objective	objective <id> += 1	Advance an ObjectiveSystem objective (=, +=, -=); emits objective.progress/objective.complete.
set_worldflag	set_worldflag <name> <value>	Write a cross-instance world flag (survives across entities, serialised with the world).
get_worldflag	get_worldflag <name>	Read a world flag into $result.
give_xp	give_xp 50	Add player XP.
grant_item	grant_item "Medkit" [qty]	Spawn an entity def and place it in the hotbar.
teleport	teleport x y z	Move the player (engine Y-up space).
change_world	change_world "Dust_Ravine"	Request a world load.
apply_area_damage	apply_area_damage <radius> <damage>	Damage pawns around the player.
spawn_projectile	spawn_projectile <speed> <damage> <life> [count] [spread]	Fire a projectile from the player.
play_clip	play_clip "Attack"	Plays a named one-shot skeletal clip and returns to Idle. Two legs: a forced clip on matching pawns (PawnSystem::PlayPawnClip), and — when the command matches the held weapon def — the first-person view-model (ViewModel::PlayClip). The no-pawn warn fires only when neither leg plays.

Events (subscription)

The engine publishes facts on the EventBus; a def subscribes by declaring an
action named on_<topic> with . replaced by _:

Topic	Action	Emitted when
world.load	on_world_load	A world finishes loading
entity.death	on_entity_death	A pawn's FSM enters DEAD (s0 = pawn def name)
entity.chase / entity.patrol / entity.return	matching on_entity_*	Pawn FSM transitions
pickup.collect	on_pickup_collect	A pickup is collected (s0 = pickup def name)
player.hurt / player.death	on_player_hurt / on_player_death	Player takes damage / dies
trigger.enter / trigger.exit	on_trigger_enter / on_trigger_exit	Player crosses an OZONE trigger volume (s0 = trigger def name)

Triggers (OZONE)

A trigger line places a volume whose meaning is a : trigger def:

trigger Trigger_EnterVolume minX minY minZ maxX maxY maxZ [once] [team=N]

On the player's entry/exit the engine emits trigger.enter / trigger.exit
with the def name; once latches after the first entry.

Conditions

Used in if statements within action blocks (both styles work):

if ($health <= 0) {
    say "Player defeated"
    end
}

if ($result == 0)
    say "first time"
endif

Supported operators: ==, !=, >, <, >=, <=, plus &&, || and
parentheses (e.g. if (($a == 1 || $b == 2) && $c > 0)).

Example: Ranged Weapon (automag)

entity "automag" : weapon {
    mesh = "automag_lvl1.obj"
    texture = "automag_lvl1_texture.png"
    stats {
        damage = 15
        fire_rate = 0.4
        magazine = 12
        reload_time = 2.0
        projectile_lifetime = 2.5
    }
    actions {
        on_fire {
            say "Bang! (15 damage)"
            set_cooldown 0.4
        }
        on_reload {
            say "Reloading..."
        }
    }
    variants {
        "lvl1" { mesh_override = "automag_lvl1.obj" }
        "lvl2" { mesh_override = "automag_lvl2_alt.obj" }
        "lvl3" { mesh_override = "automag_heavy_rifle_lvl3.obj" }
    }
}

variants are resolved when the instance spawns: the engine parses the lvlN
name for its tier and picks the highest tier that does not exceed the player's
level (clamped to the highest declared tier). A level-1 player therefore always
sees lvl1. The chosen variant applies to both the world pickup and the
first-person view-model. Names without an lvlN prefix are treated as tier 0.
Override mesh_override paths are resolved relative to the def's own directory,
so include the file extension.

Declarative zone environment

A skyzone entity can author its atmosphere directly rather than through
set_fog / set_ambient opcodes. These are applied when the player enters the
zone:

entity "skyzone_citadel" : skyzone {
    skybox = "..."
    music = "..."            // asset prefix, handed to SoundManager::PlayWorldMusic
    fog_color = (0.62, 0.52, 0.46)
    fog_density = 0.0022
    ambient_light = (0.50, 0.46, 0.46)

    actions {
        on_enter { msg "..." }
        on_exit  { restore_fog   }
    }
}

fog_color, fog_density and ambient_light are applied on on_enter; the
restore_fog / restore_ambient / restore_skybox opcodes revert them to the
level defaults. Note the vec3 syntax is name = (x, y, z) — a vec3 prefix
does not parse.

Example: Zone with Damage Loop (acidpool)

entity "acidpool" : skyzone {
    actions {
        on_enter {
            wtflag 0 1
            var timer = 60
            play_sound "GameData/Audio/Sounds/Entities/Hurt.mp3"
            msg "Acid! The pooled run-off burns your boots!"
        }
        on_tick {
            if ($flag0 >= 1) {
                $timer = $timer - 1
                if ($timer <= 0) {
                    playerstat health -= 5
                    var timer = 60
                }
            }
        }
        on_exit {
            wtflag 0 0
            msg "You scramble clear of the acid."
        }
    }
}

Integration

• Entity .ozls files are parsed by LightningScriptParser into EntityDef structs (recursively scanned from all of GameData/ + packages)
• LightningEntityRegistry stores all registered definitions
• LightningEntityManager manages runtime instances with individual LightningScriptContext per instance
• Instances start idle — action bodies run only when triggered (spawn does not auto-execute)
• Hotbar integration: slot selection triggers on_equip/on_unequip; use triggers on_use
• Zone triggers: PawnSystem calls zone actions on entry/exit; pawn FSM transitions dispatch the matching on_* action