GameObjects and Components

Axolotl2D uses a composition model similar to Unity: a GameObject supplies identity, activation, and a Transform; components add behavior and rendering.

Create an object

Instantiate objects from the active scene:

var player = Instantiate("Player");
player.Transform.LocalPosition = new Vector2(100, 80);

var renderer = player.AddComponent<SpriteRenderer>();
renderer.Sprite = new Sprite(assets.Get<Texture2D>("player"));

player.AddComponent<PlayerController>();

The returned object belongs to the scene immediately. Its components receive dependencies from the current scene scope.

Write a component

Every component constructor accepts its owning GameObject. Other parameters can be resolved by DI:

public sealed class PlayerController(
    GameObject gameObject,
    MovementSettings settings) : Component(gameObject)
{
    public override void Update(double deltaTime)
    {
        var distance = settings.Speed * (float)deltaTime;
        Transform.Translate(Vector2.UnitX * distance);
    }
}

Use GameObject, Transform, Enabled, IsActiveAndEnabled, and HasStarted from the component base class. Components do not need to locate global state through static accessors.

Find and remove components

var renderer = player.GetComponent<SpriteRenderer>();

if (renderer is not null)
{
    renderer.Tint = Color.Red;
}

player.RemoveComponent<PlayerController>();

GetComponent<T>() returns the first matching component. Removing a component invokes its disable and destruction callbacks as applicable, then disposes it.

Activation

GameObject.Active controls all components on the object. Component.Enabled controls one component:

player.Active = false;
renderer.Enabled = false;

IsActiveAndEnabled is true only when both values allow the component to run. State changes trigger OnEnable or OnDisable; they do not repeat Awake or Start.

Custom GameObject types

Use the generic overload when a domain-specific object type is useful:

public sealed class EnemyObject(
    IServiceProvider services,
    string name,
    EnemyCatalog catalog) : GameObject(services, name)
{
    public EnemyCatalog Catalog { get; } = catalog;
}

var boss = Instantiate<EnemyObject>("Boss");

The factory passes the requested name and resolves the other constructor arguments from the scene scope. Prefer components for reusable behavior; custom GameObject subclasses are best kept for meaningful domain identity or construction rules.