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我目前正在用 C# 创建一个 2D 游戏引擎。目前，我正在实现一个实体组件系统。

我的结构如下：

  • Entity Class : 包含IGameComponent's 的列表，可以按类类型添加、删除和删除任何组件。（即；entity.RemoveComponent(typeof(Transform));。它还包含一个父实体和一个子实体列表。
  • IGameComponent 接口：目前，只是一个空接口。（注意：组件只包含数据，不包含功能）
  • 实体池：包含游戏中所有活动对象的列表，它也用于创建和销毁实体。

到目前为止一切都很棒。

但是，我面临一个问题。由于组件只包含数据，我需要一种方法来初始化、更新和渲染组件，我宁愿不只是向 GameComponent 类添加一堆虚拟方法，但我不知道有任何其他方法可以解决它。

我有哪些选择？

编辑：

我已经看到 Unity 使用像“SendMessage”这样的方法，我只能假设使用反射来调用方法。我应该实现类似的东西吗？

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1 回答 1

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我不知道你是否还需要它，但几年前我做了类似的东西，它可能会对你有所帮助。它是用 C# 编写的，建立在 MonoGame/XNA 之上

你的 GameObject 类可能看起来像这样

public class GameObject
{
    List<GameObjectComponent> _goComponent = new List<GameObjectComponent();

    public T GetComponent<T>() where T : GameObjectComponent
    {
        foreach (GameObjectComponent goc in _goComponent)
            if (goc.GetType().Equals(typeof(T)))
                return (T)goc;
        return null;
    }

    public void AddComponent(GameObjectComponent gameObjectComponent)
    {
        _goComponent.Add(gameObjectComponent);
        gameObjectComponent.gameObject = this;
        gameObjectComponent.Init();
    }

    public virtual void Update(GameTime gameTime)
    {
        foreach (GameObjectComponent _goc in _goComponent)
            _goc.Update(gameTime);
    }

    public static void Instantiate(GameObject gameObject)
    {
       Scene._AddedGO.Add(gameObject);
    }

    public static void Destroy(GameObject gameObject)
    {
       Scene._RemoveGO.Add(gameObject);
    }

}

GameObjectComponent 类似于 Unity3D 的 MonoBehaivior

  public class GameObjectComponent
{

    public GameObject gameObject;

    public GameObjectComponent()
    {

    }

    public virtual void Init()
    {

    }

    public virtual void Update(GameTime gameTime)
    {

    }
}

然后你继承其他类，如下所示：

public class Sprite : GameObjectComponent
{
    public Texture2D texture;
    public Vector2 origin = Vector2.Zero;
    public Rectangle rect;
    public Rectangle sourceRect;
    public Color color = Color.White;
    public float rotation = 0f;
    private float layerDepth = 0f;
    public int scale = 1;

    public Sprite()
    {

    } 

    public void Load(string path)
    {
        texture = Setup.ContentDevice.Load<Texture2D>(path);
    }

}

现在你终于可以创建你的 Player GameObject

class Player : GameObjectComponent
{
    float speed = 150f;
    KeyboardState keyState;

    float pos_X;
    float pos_Y;
    int rect_X;
    int rect_Y;

    public Player(float x, float y, int rx, int ry)
    {
        pos_X = x;
        pos_Y = y;
        rect_X = rx;
        rect_Y = ry;
    }

    public override void Init()
    {
        Sprite sprite = new Sprite();
        gameObject.AddComponent(sprite);

        gameObject.GetComponent<Sprite>().Load("Sprites/MainGuySpriteSheet_0");
        gameObject.GetComponent<Sprite>().scale = 1;
        gameObject.GetComponent<Sprite>().rect = new Rectangle(46, 0, 32, 36);


        Transform transform = new Transform();
        gameObject.AddComponent(transform);
        //  gameObject.GetComponent<Transform>().position = new Vector2(Screen.width / 2 - gameObject.GetComponent<Sprite>().rect.Width, Screen.height / 2 - gameObject.GetComponent<Sprite>().rect.Height);
        gameObject.GetComponent<Transform>().position = new Vector2(pos_X, pos_Y - 32 * (gameObject.GetComponent<Sprite>().scale - 1));

        RectCollider collider = new RectCollider();
        gameObject.AddComponent(collider);
        gameObject.GetComponent<RectCollider>().Set(gameObject.GetComponent<Sprite>(), gameObject.GetComponent<Transform>());

        SpriteRenderer render = new SpriteRenderer();
        gameObject.AddComponent(render);
        gameObject.GetComponent<SpriteRenderer>().layer = 1;
        gameObject.GetComponent<SpriteRenderer>().Set(gameObject.GetComponent<Sprite>());
    }

    public override void Update(GameTime gameTime)
    {
        //movex = transform.position.X -= 25 * gameTime.DeltaTime();


        if (Keyboard.GetState().IsKeyDown(Keys.Left))
            gameObject.GetComponent<Transform>().Move(-speed * gameTime.DeltaTime(), 0);

       else if (Keyboard.GetState().IsKeyDown(Keys.Right))
            gameObject.GetComponent<Transform>().Move(speed * gameTime.DeltaTime(), 0);

       else if (Keyboard.GetState().IsKeyDown(Keys.Down))
            gameObject.GetComponent<Transform>().Move(0, speed * gameTime.DeltaTime());

       else if (Keyboard.GetState().IsKeyDown(Keys.Up))
            gameObject.GetComponent<Transform>().Move(0, -speed * gameTime.DeltaTime());

        if (Keyboard.GetState().IsKeyDown(Keys.Space) && !keyState.IsKeyDown(Keys.Space))
        {
            GameObject tomato = new GameObject();
            tomato.AddComponent(new Tomato());
            tomato.GetComponent<Transform>().position = gameObject.GetComponent<Transform>().position;
            GameObject.Instantiate(tomato);
        }

        if (Keyboard.GetState().IsKeyDown(Keys.Q) && !keyState.IsKeyDown(Keys.Q))
        {
            SceneManager.LoadScene(new AnotherOne());
        }

        keyState = Keyboard.GetState();


        gameObject.GetComponent<Transform>().position.Y = MathHelper.Clamp(gameObject.GetComponent<Transform>().position.Y, 0, Screen.bounds.Height - gameObject.GetComponent<Sprite>().rect.Height * gameObject.GetComponent<Sprite>().scale);
        gameObject.GetComponent<Transform>().position.X = MathHelper.Clamp(gameObject.GetComponent<Transform>().position.X, 0, Screen.bounds.Width - gameObject.GetComponent<Sprite>().rect.Width * gameObject.GetComponent<Sprite>().scale);
    }

}

我希望它不会太令人困惑并且对您有所帮助。为了更清楚，我在这里留下了 git 的链接：https ://github.com/Memorix101/MonoGame_ComponentSystem

干杯，Memorix101 :)

于 2018-01-31T17:55:32.553 回答