Black bars on 720p emulator?

Question

I'm making a game for Windows Phone 8 using XNA 4.0 in Visual Studio express 2012. I'm trying to add a background image to the game with a size of 1366x768 (as i believe WP8 only supports up to 720p). Everything stretches![enter image description here][2] well on the other emulators (WVGA and WXGA) until i use the 720p emulator and i get black bars on the sides. (picture) http://i46.tinypic.com/30crj44.png This is all the code i have used so far:

GraphicsDeviceManager graphics;
    SpriteBatch spriteBatch;
    Texture2D Background;

    public Game1()
    {
        graphics = new GraphicsDeviceManager(this);
        Content.RootDirectory = "Content";

        graphics.SupportedOrientations = DisplayOrientation.LandscapeLeft | DisplayOrientation.LandscapeRight;

        this.graphics.IsFullScreen = true;

        // Frame rate is 30 fps by default for Windows Phone.
        TargetElapsedTime = TimeSpan.FromTicks(333333);

        // Extend battery life under lock.
        InactiveSleepTime = TimeSpan.FromSeconds(1);
    }

    /// <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

        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);

        Background = Content.Load<Texture2D>("SkyBackground");

    }

    /// <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)
    {
        // Allows the game to exit
        if (GamePad.GetState(PlayerIndex.One).Buttons.Back == ButtonState.Pressed)
            this.Exit();

        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.CornflowerBlue);

        // TODO: Add your drawing code here
        spriteBatch.Begin();
        drawBackground();
        spriteBatch.End();

        base.Draw(gameTime);
    }

    private void drawBackground()
    {
        spriteBatch.Draw(Background, GraphicsDevice.Viewport.Bounds, Color.White);
    }

How can i fix this, or is this normal? Any help for a noob like me would be appreciated :)

Answer 1

It looks like XNA games are always clamped at a maximum resolution of 800x480; even changing the PreferredBackBufferWidth and PreferredBackBufferHeight parameters doesn't prevent it from using a scaled-up + letterboxed framebuffer.

Answer 2

I've run into this problem before and I've described how to solve it (or to better phrase it, how to work around it) on Nokia Community Wiki article: Fullscreen XNA games on Windows Phone 8 devices.

r2d2rigo is right, you need to change aspect ratio when running on WP8 devices.