/godot-composition

Orchestrator Recipes (load on demand)

MANDATORY when wiring Input → Movement → Health orchestrators beyond composition_root_init.gd. Components live in scripts/ — this file holds pedagogy only.

Typed export orchestrator

class_name Player extends CharacterBody3D

@export var health_component: HealthComponent
@export var movement_component: VelocityComponent
@export var input_component: Node  # project-specific InputComponent

func _physics_process(delta: float) -> void:
	if input_component.has_method(&"update"):
		input_component.call(&"update")
	if movement_component and input_component.has_method(&"get_move_dir"):
		var dir: Vector2 = input_component.call(&"get_move_dir")
		movement_component.tick(delta, dir)

Input component (senses only)

Reads hardware; does not move the body.

class_name InputComponent extends Node

var move_dir: Vector2
var jump_pressed: bool

func update() -> void:
	move_dir = Input.get_vector("left", "right", "up", "down")
	jump_pressed = Input.is_action_just_pressed("jump")

Prefer godot-input-handling for action maps.

Movement component (legs)

class_name MovementComponent extends Node

@export var body: CharacterBody3D
@export var speed: float = 8.0
@export var jump_velocity: float = 12.0

func tick(delta: float, direction: Vector2, wants_jump: bool) -> void:
	if not body:
		return
	if not body.is_on_floor():
		body.velocity.y -= 9.8 * delta
	body.velocity.x = direction.x * speed if direction else move_toward(body.velocity.x, 0, speed)
	if wants_jump and body.is_on_floor():
		body.velocity.y = jump_velocity
	body.move_and_slide()

Production movement: velocity_component.gd.

Health component

health_component.gd — context-agnostic HP; orchestrator connects died to despawn/VFX.

State-component FSM

state_component_vsm.gd — child nodes as states. Deeper FSMs: godot-state-machine-advanced.

Component registry

O(1) lookup by name or group — orchestrator-private; still no sideways sibling calls.

var _components: Dictionary = {}

func _ready() -> void:
	for child in get_children():
		_components[child.name] = child
		for group in child.get_groups():
			_components[group] = child

func get_comp(key: StringName) -> Node:
	return _components.get(key)

Dependency validation

CAUTION: assert() strips in release — use @export typed slots + null checks for shipping builds.

@export var health_component: HealthComponent

func _ready() -> void:
	assert(health_component != null, "Missing HealthComponent export!")