Class hierarchy for ship game

Here's the basic class hierarchy I made:

Code:

    public abstract class sprite
    {
        protected int Xposition;
        protected int Yposition;
        protected int Xsize;
        protected int Ysize;
        protected int Yspeed;
        protected int Xspeed;
        public int hp;
        public int damage;
        protected Texture2D tex;
        public Rectangle rect;

        public abstract bool update(sprite[] onscreen, SpriteBatch sb, Camera cam);      //If update returns false, we kill the sprite

        protected void updatepos()
        {
            Xposition += Xspeed;
            Yposition += Yspeed;
        }

        public int[,] GetClipping()
        {
            int[,] clipping = { { Xposition, Yposition }, { Xposition + Xsize, Yposition + Ysize } };
            return clipping;
        }

        public bool checkclipping(sprite sp)
        {
            return rect.Intersects(sp.rect);         
        }
    }
    public abstract class ship : sprite
    {
        public abstract void hit(sprite sp);
    }

    public abstract class goodship : ship
    {
    }

    public abstract class badship : ship
    {
    }

    public abstract class bullet : sprite
    {
        protected int lifetimer;
    }

The point of this is to keep everything grouped together in a way that makes them easy to use in the future. What we want to do is make functions as high "up" on the class hierarchy as possible, for instance, every sprite is going to have a get clipping routine, so that one goes at the very top of the tree. Different types of good ships would do different things, but there is bound to be any number of things they have in common, just as a good ship has a lot in common with a bad ship. So yeah, class hierarchy, extend these to make different types of what I already put in here.

P.S. the code boxes on this forum are painful with the current color scheme. Someone's gonna have to do something about that.

Edit: Added update position function in the base sprite class. It's only preliminary, so if someone has a better function for that, let me know. Also: I suggest that all new classes we code (Ships, bullets, etc.) all be placed in here for easy organization.

Edit2: I dun edited it again. Not that anyone has looked at this before I edited it, so I won't even bother saying what I changed. I also created a naive camera class:

Code:

    public class Camera
    {
        private int Xpos;
        private int Ypos;
        private int Xsize;
        private int Ysize;
        private int xspeed = 0;
        private int yspeed = 0;
        private delegate void function();  //This is going to need to be edited for whatever we want to pass to the update functions
                                            //(In case you didn't figure it out, this is a callback. You write a funciton then just pass that here, the camera will update using that function.
                                            //This is for greater extendability
        private function updatefunc;

        public void setupdate(Delegate func)
        {
            updatefunc = (function)func;
        }

        public Camera(int x, int y, int xs, int ys)
        {
            Xpos = x; Ypos = y; Xsize = xs; Ysize = ys;
        }
       
        public void move(int x, int y)
        {
            Xpos += x;
            Ypos += y;
        }

        public int get_Xpos()
        {
            return Xpos;
        }

        public int get_Ypos()
        {
            return Ypos;
        }

        public int get_Xsize()
        {
            return Xsize;
        }

        public int get_Ysize()
        {
            return Ysize;
        }

        public void update()
        {
            updatefunc();
        }
    }

And, finally, finished the first bullet class to get the idea I'm going for in building these accross:

Code:

    public class standardgoodbullet : bullet
    {
        public standardgoodbullet(int x, int y, int w, int h, int xs, int ys)
        {
            hp = 1;
            damage = 10;
            lifetimer = 40;
            Xposition = x;
            Yposition = y;
            Xsize = w;
            Ysize = h;
            Yspeed = ys;
            Xspeed = xs;
        }

        private void interact(ship s)
        {
            if (checkclipping(s))
            {
                s.hit(this);
            }
        }

        private void draw(SpriteBatch sb, Camera cam)
        {
            int drawposx1 = Xposition - cam.get_Xpos();
            int drawposy1 = Yposition - cam.get_Ypos();
            int drawposx2 = drawposx1 - Xspeed;
            int drawposy2 = drawposy1 - Yspeed;
            int drawposx3 = drawposx2 - Xspeed - Xspeed;
            int drawposy3 = drawposy2 - Yspeed - Yspeed;
            Random random = new Random();
            byte r1 = (byte)random.Next(0, 256);
            byte r2 = (byte)random.Next(0, 256);
            byte r3 = (byte)random.Next(0, 256);
            byte b1 = (byte)random.Next(0, 256);
            byte b2 = (byte)random.Next(0, 256);
            byte b3 = (byte)random.Next(0, 256);
            byte g1 = (byte)random.Next(0, 256);
            byte g2 = (byte)random.Next(0, 256);
            byte g3 = (byte)random.Next(0, 256);
            sb.Draw(tex, new Rectangle(drawposx1, drawposy1, Xsize, Ysize), new Color(r1, b1, g1));
            sb.Draw(tex, new Rectangle(drawposx2, drawposy2, Xsize, Ysize), new Color(r2, b2, g2));
            sb.Draw(tex, new Rectangle(drawposx3, drawposy3, Xsize, Ysize), new Color(r3, b3, g3));

        }

        public override bool update(sprite[] onscreen, SpriteBatch sb, Camera cam)
        {
            updatepos();
            lifetimer -= 1;
            rect = new Rectangle(Xposition, Yposition, Xsize, Ysize);
            draw(sb, cam);
            foreach (sprite i in onscreen)
            {
                if (i is badship)
                {
                    interact((ship)i);
                }
            }
            if (lifetimer <= 0 ||
                hp <= 0)
            {
                return false;
            }
            else
            {
                return true;
            }
        }
    }

No time to test all this right now, but it at least compiles.

Here is a great place to find info on making bullets and weapons

http://davisxna.wordpress.com/2011/04/21/topdownshooter-part-3-weapons-and-bullets/