godot-patterns

Godot Patterns

Typed GDScript Class Structure

class_name PlayerCharacter extends CharacterBody3D
## Player character controller with movement and combat.
## Requires: CollisionShape3D child, AnimationTree child

signal died
signal health_changed(old_health: float, new_health: float)

const SPEED: float = 6.0
const JUMP_VELOCITY: float = 5.5
const GRAVITY: float = 9.8

@export var max_health: float = 100.0
@export var weapon_data: WeaponData  # Resource reference

@onready var animation_tree: AnimationTree = $AnimationTree
@onready var weapon_pivot: Node3D = $WeaponPivot
@onready var health_bar: ProgressBar = %HealthBar  # % = unique name shortcut

var _current_health: float
var _is_dead: bool = false

func _ready() -> void:
    _current_health = max_health
    animation_tree.active = true

func _physics_process(delta: float) -> void:
    if _is_dead:
        return
    _handle_gravity(delta)
    _handle_movement()
    move_and_slide()

func take_damage(amount: float) -> void:
    if _is_dead:
        return
    var old_health := _current_health
    _current_health = maxf(0.0, _current_health - amount)
    health_changed.emit(old_health, _current_health)
    if _current_health <= 0.0:
        _die()

func _die() -> void:
    _is_dead = true
    set_physics_process(false)  # Stop physics checks, cheaper than bool guard
    died.emit()

func _handle_gravity(delta: float) -> void:
    if not is_on_floor():
        velocity.y -= GRAVITY * delta

func _handle_movement() -> void:
    var input_dir := Input.get_vector(
        &"move_left", &"move_right", &"move_forward", &"move_back"
    )
    var direction := (transform.basis * Vector3(input_dir.x, 0, input_dir.y)).normalized()
    if direction:
        velocity.x = direction.x * SPEED
        velocity.z = direction.z * SPEED
    else:
        velocity.x = move_toward(velocity.x, 0, SPEED)
        velocity.z = move_toward(velocity.z, 0, SPEED)

Scene Inheritance Pattern

# Base scene: Enemy.tscn with Enemy.gd
class_name Enemy extends CharacterBody3D
@export var move_speed: float = 3.0
@export var health: float = 50.0

func _ready() -> void:
    _setup()

func _setup() -> void:
    pass  # Override in subclasses

func attack(target: Node3D) -> void:
    pass  # Override in subclasses

# Inherited scene: GoblinEnemy.tscn extends Enemy.tscn
class_name GoblinEnemy extends Enemy

func _setup() -> void:
    move_speed = 4.0  # Goblins are faster
    health = 30.0

func attack(target: Node3D) -> void:
    # Goblin-specific attack logic
    pass