Designing Game Objects

I recently started working on a small game for my own amusement, using Microsoft XNA and C#. My question is in regards to designing a game object and the objects that inherit it. I'm going to define a game object as something that can be rendered on screen. So for this, I decided to make a base class which all other objects that will need to be rendered will inherit, called GameObject. The code below is the class I made:

class GameObject
{
    private Model model = null;
    private float scale = 1f;
    private Vector3 position = Vector3.Zero;
    private Vector3 rotation = Vector3.Zero;
    private Vector3 velocity = Vector3.Zero;
    private bool alive = false;
    protected ContentManager content;

    #region Constructors
    public GameObject(ContentManager content, string modelResource)
    {
        this.content = content;
        model = content.Load<Model>(modelResource);
    }
    public GameObject(ContentManager content, string modelResource, bool alive)
        : this(content, modelResource)
    {
        this.alive = alive;
    }
    public GameObject(ContentManager content, string modelResource, bool alive, float scale)
        : this(content, modelResource, alive)
    {
        this.scale = scale;
    }
    public GameObject(ContentManager content, string modelResource, bool alive, float scale, Vector3 position)
        : this(content, modelResource, alive, scale)
    {
        this.position = position;
    }
    public GameObject(ContentManager content, string modelResource, bool alive, float scale, Vector3 position, Vector3 rotation)
        : this(content, modelResource, alive, scale, position)
    {
        this.rotation = rotation;
    }
    public GameObject(ContentManager content, string modelResource, bool alive, float scale, Vector3 position, Vector3 rotation, Vector3 velocity)
        : this(content, modelResource, alive, scale, position, rotation)
    {
        this.velocity = velocity;
    }
    #endregion
}

                    
                    
                        
                        c#
                        
                        oop
                        
                        xna
                        
                    
                    
                        
                        
                        
                        
                        
                        Edit
                        
                        
                        
                            
                        
                        
                        Report

Not only is the number of constructors a potential issue (especially having to re-define them for each derived class) - but the number of parameters to the constructor can become an issue. Even if you make the optional parameters nullable, it becomes difficult to read and maintain the code later.

If I write:

new Ship(content, "resource", true, null, null, null, null);

What does the second NULL do?

It makes code more readable (but more verbose) to use a structure to hold your parameters if the parameter list goes beyond four or five parameters:

GameObjectParams params(content, "resource");
params.IsAlive = true;
new Ship(params);

There are a lot of ways this can be done.

answered 2008-10-07T21:47:29.933

1 Answer

Your Answer