/DashXna/DashXna/Game/IntroScreen.cs

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;

using System.Xml.Linq;

using Microsoft.Xna.Framework.Input.Touch;





namespace Dash

{

    /// <summary>

    /// This is a game component that implements IUpdateable.

    /// </summary>

    public class IntroScreen : Microsoft.Xna.Framework.DrawableGameComponent

    {

        SpriteBatch spriteBatch;

        SpriteFont font;

        Texture2D background;

        string story;

        Vector2 textSize;

        double textOffset;

        double opacity = 1;



        public IntroScreen(Game game)

            : base(game)

        {

            DrawOrder = 15;

        }



        /// <summary>

        /// Allows the game component to perform any initialization it needs to before starting

        /// to run.  This is where it can query for any required services and load content.

        /// </summary>

        public override void Initialize()

        {

            // TODO: Add your initialization code here



            base.Initialize();

        }



        protected override void LoadContent()

        {

            font = Game.Content.Load<SpriteFont>("Default");

            spriteBatch = new SpriteBatch(Game.GraphicsDevice);

            background = Game.Content.Load<Texture2D>("StoryBackground");



            XDocument doc = XDocument.Load(TitleContainer.OpenStream("Content\\Intro-Story.xml"));



            story = doc.Descendants("story").First().Element("text").Value;

            textSize = font.MeasureString(story);

            textOffset = 500;



            base.LoadContent();

        }



        /// <summary>

        /// Allows the game component to update itself.

        /// </summary>

        /// <param name="gameTime">Provides a snapshot of timing values.</param>

        public override void Update(GameTime gameTime)

        {

            textOffset -= gameTime.ElapsedGameTime.TotalSeconds * 40;



            if (TouchPanel.GetState().Any())

                textOffset = -5000;

            

            if (textOffset < -textSize.Y)

            {

                if (opacity > 0)

                {

                    opacity -= gameTime.ElapsedGameTime.TotalSeconds * 0.5f;

                }

                else

                {

                    this.Enabled = false;

                    this.Visible = false;

                    (Game.Services.GetService(typeof(GameplayComponent)) as GameplayComponent).Enabled = true;

                }

            }



            base.Update(gameTime);

        }



        public override void Draw(GameTime gameTime)

        {

            var transform = Matrix.Identity;



            spriteBatch.Begin(SpriteSortMode.Deferred, BlendState.AlphaBlend, SamplerState.LinearClamp, DepthStencilState.Default,

                RasterizerState.CullNone, null, transform);



            spriteBatch.Draw(background, new Vector2(0, 0), new Color(1, 1, 1, (float)opacity));



            spriteBatch.DrawString(font, "The Story (Tap to skip)", new Vector2(40, (float)textOffset - 10), Color.Gray);

            spriteBatch.DrawString(font, story, new Vector2(40, (int)(10 + textOffset)), Color.White);



            spriteBatch.End();



            base.Draw(gameTime);

        }

    }

}