using System;using System.Collections.Generic;using System.Linq;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;using Microsoft.Xna.Framework.Media;namespace WindowsGame2{    /// <summary>    /// This is the main type for your game    /// </summary>    public class Game1 : Microsoft.Xna.Framework.Game    {        GraphicsDeviceManager graphics;        SpriteBatch spriteBatch;        KeyboardState kb;        VertexPositionColor[] vertices = new VertexPositionColor[4];        BasicEffect effect;        public Game1()        {            graphics = new GraphicsDeviceManager(this);            Content.RootDirectory = "Content";        }        /// <summary>        /// Allows the game to perform any initialization it needs to before starting to run.        /// This is where it can query for any required services and load any non-graphic        /// related content.  Calling base.Initialize will enumerate through any components        /// and initialize them as well.        /// </summary>        protected override void Initialize()        {            // TODO: Add your initialization logic here            effect = new BasicEffect(graphics.GraphicsDevice);            effect.VertexColorEnabled = true;            effect.Projection = Matrix.CreateOrthographicOffCenter(0, graphics.GraphicsDevice.Viewport.Width, graphics.GraphicsDevice.Viewport.Height, 0, 1, 0);            graphics.PreferredBackBufferWidth = 1024;            graphics.PreferredBackBufferHeight = 768;            Window.Title = "Matrix Math";            graphics.ApplyChanges();                       vertices[0] = new VertexPositionColor(new Vector3(-2.0f, 2.0f, -1.5f), Color.CadetBlue);            vertices[1] = new VertexPositionColor(new Vector3(2.0f, 2.0f, -1.5f), Color.Blue);            vertices[2] = new VertexPositionColor(new Vector3(-2.0f, -2.0f, -1.5f), Color.Brown);            vertices[3] = new VertexPositionColor(new Vector3(2.0f, -2.0f, -1.5f), Color.Crimson);            kb = Keyboard.GetState();            base.Initialize();        }        /// <summary>        /// LoadContent will be called once per game and is the place to load        /// all of your content.        /// </summary>        protected override void LoadContent()        {            // Create a new SpriteBatch, which can be used to draw textures.            spriteBatch = new SpriteBatch(GraphicsDevice);            // TODO: use this.Content to load your game content here        }        /// <summary>        /// UnloadContent will be called once per game and is the place to unload        /// all content.        /// </summary>        protected override void UnloadContent()        {            // TODO: Unload any non ContentManager content here        }        /// <summary>        /// Allows the game to run logic such as updating the world,        /// checking for collisions, gathering input, and playing audio.        /// </summary>        /// <param name="gameTime">Provides a snapshot of timing values.</param>        protected override void Update(GameTime gameTime)        {            KeyboardState newstate = Keyboard.GetState();            if (newstate.IsKeyDown(Keys.Escape) && (graphics.IsFullScreen))            {                if (!kb.IsKeyDown(Keys.Escape))                {                    graphics.IsFullScreen = false;                    graphics.ApplyChanges();                }            }            else if (newstate.IsKeyDown(Keys.Escape) && (!graphics.IsFullScreen))            {                if (!kb.IsKeyDown(Keys.Escape))                {                    graphics.IsFullScreen = true;                    graphics.ApplyChanges();                }            }            kb = newstate;            // TODO: Add your update logic here            base.Update(gameTime);        }        /// <summary>        /// This is called when the game should draw itself.        /// </summary>        /// <param name="gameTime">Provides a snapshot of timing values.</param>        protected override void Draw(GameTime gameTime)        {            GraphicsDevice.Clear(Color.MediumAquamarine);                        effect.CurrentTechnique.Passes[0].Apply();            graphics.GraphicsDevice.DrawUserPrimitives<VertexPositionColor>(PrimitiveType.TriangleStrip, vertices, 0, 2);            // TODO: Add your drawing code here                        base.Draw(gameTime);        }    }}