Godot Code Review

# BAD: tight coupling, breaks if the tree changes
func take_damage(amount: int) -> void:
    get_parent().get_parent().get_node("HUD").update_health(health)

// BAD: tight coupling, breaks if the tree changes
public void TakeDamage(int amount)
{
    GetParent().GetParent().GetNode("HUD").Call("UpdateHealth", _health);
}

# GOOD: parent/ancestor listens; child stays decoupled
signal health_changed(new_health: int)

func take_damage(amount: int) -> void:
    health -= amount
    health_changed.emit(health)

// GOOD: parent/ancestor listens; child stays decoupled
[Signal]
public delegate void HealthChangedEventHandler(int newHealth);

public void TakeDamage(int amount)
{
    _health -= amount;
    EmitSignal(SignalName.HealthChanged, _health);
}

var speed = 200
var health = 100

func move(direction):
    position += direction * speed

func heal(amount):
    health += amount
    return health

// BAD: no explicit types, weak contracts
float speed = 200;
int health = 100;

public void Move(object direction)
{
    Position += (Vector2)direction * speed;
}

public object Heal(object amount)
{
    health += (int)amount;
    return health;
}

class_name PlayerController
extends CharacterBody2D

signal health_changed(new_health: int)
signal player_died()

const MAX_HEALTH: int = 100
const BASE_SPEED: float = 200.0

@export var speed: float = BASE_SPEED
@export var max_health: int = MAX_HEALTH

var health: int = max_health

func move(direction: Vector2) -> void:
    velocity = direction * speed
    move_and_slide()

func heal(amount: int) -> int:
    health = mini(health + amount, max_health)
    health_changed.emit(health)
    return health

// GOOD: strongly typed, proper C# conventions
public partial class PlayerController : CharacterBody2D
{
    [Signal]
    public delegate void HealthChangedEventHandler(int newHealth);
    [Signal]
    public delegate void PlayerDiedEventHandler();

    private const int MaxHealth = 100;
    private const float BaseSpeed = 200f;

    [Export] public float Speed { get; set; } = BaseSpeed;
    [Export] public int MaxHp { get; set; } = MaxHealth;

    private int _health;

    public override void _Ready()
    {
        _health = MaxHp;
    }

    public void Move(Vector2 direction)
    {
        Velocity = direction * Speed;
        MoveAndSlide();
    }

    public int Heal(int amount)
    {
        _health = Mathf.Min(_health + amount, MaxHp);
        EmitSignal(SignalName.HealthChanged, _health);
        return _health;
    }
}

// GOOD
public partial class PlayerController : CharacterBody2D
{
    [Signal]
    public delegate void HealthChangedEventHandler(int newHealth);

    [Export] public float Speed { get; set; } = 200f;
    [Export] public int MaxHealth { get; set; } = 100;

    private int _health;
    private AnimationPlayer _animationPlayer = null!;

    public override void _Ready()
    {
        _animationPlayer = GetNode<AnimationPlayer>("AnimationPlayer");
        // Validate at startup rather than silently failing later
        if (_animationPlayer is null)
            GD.PushError("AnimationPlayer node not found on PlayerController");

        _health = MaxHealth;
    }

    public void TakeDamage(int amount)
    {
        _health = Mathf.Max(_health - amount, 0);
        EmitSignal(SignalName.HealthChanged, _health);
    }
}

# BAD: get_node() traverses the tree every frame
func _process(delta: float) -> void:
    get_node("HUD/HealthBar").value = health
    get_node("HUD/Label").text = str(health)

// BAD: GetNode() traverses the tree every frame
public override void _Process(double delta)
{
    GetNode<ProgressBar>("HUD/HealthBar").Value = _health;
    GetNode<Label>("HUD/Label").Text = _health.ToString();
}

# GOOD: resolved once at scene load
@onready var _health_bar: ProgressBar = $HUD/HealthBar
@onready var _health_label: Label = $HUD/Label

func _process(delta: float) -> void:
    _health_bar.value = health
    _health_label.text = str(health)

// GOOD: resolved once in _Ready()
private ProgressBar _healthBar = null!;
private Label _healthLabel = null!;

public override void _Ready()
{
    _healthBar = GetNode<ProgressBar>("HUD/HealthBar");
    _healthLabel = GetNode<Label>("HUD/Label");
}

public override void _Process(double delta)
{
    _healthBar.Value = _health;
    _healthLabel.Text = _health.ToString();
}

# BAD: new String allocation compared each frame
if animation_name == "run":
    pass

# GOOD: StringName literal, no allocation
if animation_name == &"run":
    pass

// BAD: allocates a new StringName each frame
if (animationName == "run") { }

// GOOD: cache StringName as a static field
private static readonly StringName RunAnim = new("run");

public override void _Process(double delta)
{
    if (animationName == RunAnim) { }
}

# Continuous movement — physics process
func _physics_process(delta: float) -> void:
    var direction: Vector2 = Input.get_vector(
        &"ui_left", &"ui_right", &"ui_up", &"ui_down"
    )
    velocity = direction * speed
    move_and_slide()

# Discrete action — unhandled input
func _unhandled_input(event: InputEvent) -> void:
    if event.is_action_pressed(&"jump"):
        _jump()

// Continuous movement — physics process
public override void _PhysicsProcess(double delta)
{
    Vector2 direction = Input.GetVector(
        "ui_left", "ui_right", "ui_up", "ui_down"
    );
    Velocity = direction * Speed;
    MoveAndSlide();
}

// Discrete action — unhandled input
public override void _UnhandledInput(InputEvent @event)
{
    if (@event.IsActionPressed("jump"))
    {
        Jump();
    }
}