gistfile1.cs

 using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using Microsoft.Xna.Framework;
using Microsoft.Xna.Framework.Audio;
using Microsoft.Xna.Framework.Content;
using Microsoft.Xna.Framework.GamerServices;
using Microsoft.Xna.Framework.Graphics;
using Microsoft.Xna.Framework.Input;

namespace ShipFighterClasses
{
    public class Player
    {
        // This variable will hold our position - make it a property so game class
        //can use it to change position when mouse moved
        protected Vector2 position;
        public Vector2 Position
        {
            get { return position; }
            set { position = value; }
        }
        //make these protected so derived classes can use it
        public Texture2D TextureImage { get; set; }
        //origin of sprite, either null or the center of the image
        protected Vector2 spriteOrigin;
        public Vector2 SpriteOrigin
        {
            get { return spriteOrigin; }
            set { spriteOrigin = value; }
        }

        public virtual Rectangle CollisionRectangle
        {
            get
            {
                return new Rectangle(
                   (int)(position.X - spriteOrigin.X * Scale),
                    (int)(position.Y - spriteOrigin.Y * Scale),
                    Convert.ToInt32(TextureImage.Width * Scale) ,
                    Convert.ToInt32(TextureImage.Height * Scale)
                    );
            }
        }

        //vector so it has independant x and y values
        protected Vector2 velocity;
        public Vector2 Velocity
        {
            get { return velocity; }
            set { velocity = value; }
        }

        protected Vector2 acceleration;
        public Vector2 Acceleration
        {
            get { return acceleration; }
            set { acceleration = value; }
        }

        //whether to use the Origin or not
        public bool SetOrigin { get; set; }
        public float Scale { get; set; }

        //is he active or not (should he be updated and drawn?)
        public bool Alive { get; set; }

        //simpler than Sprite, missing a few properties

        // base version
        public Player(Texture2D textureImage, Vector2 position, Vector2 velocity, Vector2 acceleration,
            bool setOrigin, float scale)
        {
            Position = position;
            TextureImage = textureImage;
            Acceleration = acceleration;
            Velocity = velocity;
            SetOrigin = setOrigin;
            if (SetOrigin)
            {
                SpriteOrigin = new Vector2(TextureImage.Width / 2, TextureImage.Height / 2);
            }
            Scale = scale;
            Alive = true;
        }

        public bool CollisionSprite(Player sprite)
        {
            return this.CollisionRectangle.Intersects(sprite.CollisionRectangle); 
        }

        //version that does not keep sprite on screen
        public virtual void Update(GameTime gameTime)
        {
            if (Alive)
            {
                // time between frames
                float timeLapse = (float)(gameTime.ElapsedGameTime.TotalSeconds);
                //move the sprite
                position += Velocity * timeLapse;
            }
        }
        //version that keeps sprite on screen
        public virtual void Update(GameTime gameTime, GraphicsDevice Device)
        {
            if (Alive)
            {
                //call overload to do rotation and basic movement
                Update(gameTime);
                //keep on screen
                if (Position.X > Device.Viewport.Width - SpriteOrigin.X * Scale)
                {                    
                    position.X = Device.Viewport.Width - SpriteOrigin.X * Scale;
                    velocity.X = -Velocity.X;
                }
                else if (Position.X < SpriteOrigin.X * Scale)
                {
                    position.X = SpriteOrigin.X * Scale;
                    velocity.X = -Velocity.X;
                }

                if (Position.Y > Device.Viewport.Height - SpriteOrigin.Y * Scale)
                {
                    position.Y = Device.Viewport.Height  - SpriteOrigin.Y * Scale;
                    velocity.Y = -Velocity.Y;
                }
                else if (Position.Y < SpriteOrigin.Y * Scale)
                {
                    position.Y = SpriteOrigin.Y * Scale;
                    velocity.Y = -Velocity.Y;
                }
            }
        }

        public virtual void Draw(SpriteBatch spriteBatch)
        {
            if (Alive)
            {
                spriteBatch.Draw(TextureImage,
                     position,
                     null,
                     Color.White,
                     0f,
                     SpriteOrigin,
                     Scale,
                     SpriteEffects.None,
                     0);
                }
        }

        public void Up()
        {
            velocity.Y -= Acceleration.Y;
        }
        public void Left()
        {
            velocity.X -= Acceleration.X;
        }
        public void Down()
        {
            velocity.Y += Acceleration.Y;
        }
        public void Right()
        {
            velocity.X += Acceleration.X;
        }
        public virtual void Idle()
        {
            Velocity *= .95f; 
        }

    
    }
}