2. Constructor and New Fields // Don't synch draw() with vertical retrace of monitor graphics.SynchronizeWithVerticalRetrace = false; IsFixedTimeStep = true; // default rate of 1/60 sec private float fps; private float updateInterval = 1.0f; private float timeSinceLastUpdate = 0.0f; private float framecount = 0; IsFixedTimeStep, when true, will cause XNA to call Update() only after TargetElapsedTime seconds have passes. In Constructor New private member fields.

3. New XNA 3.0 Windows Game In Visual Studio 2008 File -> New -> Project Project Type: XNA Game Studio 3.0 -> Windows Game (3.0) Name: Pong (or whatever you’d like) Let’s create some sprites In solution explorer Under content -> Add new item->Bitmap file Create a Ball (mine is 12x12) Might want to rename it to ball Create a Paddle -- maybe name it paddle (mine is 14x56)

4. Before we go to far what objects? Ball Position 2d vector Velocity 2d vector Paddle Position 2d vector Velocity ? Maybe, depends on if it keeps moving when user stops pressing button. For now yes What about dimensions?

5. Let’s create helper class(es) namespace Pong1 { public class Thingy { public int Height { get; set; } public int Width { get; set; } public Vector2 position { get; set; } public Vector2 motion { get; set; } public Rectangle rect { get { return new Rectangle((int)position.X, (int)position.Y, (int)Width, (int)Height); } } } public class Paddle : Thingy { } public class Ball : Thingy { } What is this?

6. Declare some variables Ball theBall; Paddle paddle1; Paddle paddle2; Texture2D ballTexture; Texture2D paddleTexture; const int SCREEN_WIDTH = 640; const int SCREEN_HEIGHT = 480;

7. Initialize() // Setup window dimensions. // We could also used defaults and query graphics.PreferredBackBufferHeight = SCREEN_HEIGHT; graphics.PreferredBackBufferWidth = SCREEN_WIDTH; graphics.PreferMultiSampling = false; graphics.ApplyChanges(); // Initialize Ball theBall = new Ball(); theBall.position = new Vector2(30, 30); theBall.motion = new Vector2(3f, 1f); theBall.Width = 12; theBall.Height = 12;

8. Initialize() // Initialize Paddles paddle1 = new Paddle(); paddle1.position = new Vector2(0, 10); paddle1.motion = new Vector2(0, 3); paddle1.Width = 14; paddle1.Height = 56; paddle2 = new Paddle(); paddle2.position = new Vector2(630, 30); paddle2.motion = new Vector2(0, -3); paddle2.Width = 14; paddle2.Height = 56;

9. Load and Display Sprites LoadContent() ballTexture = Content.Load ("ball"); paddleTexture = Content.Load ("Paddle"); Draw() spriteBatch.Begin(); spriteBatch.Draw(ballTexture, theBall.position, Color.White); spriteBatch.Draw(paddleTexture, paddle1.position, Color.Blue); spriteBatch.Draw(paddleTexture, paddle2.rect, Color.Red); spriteBatch.End(); Vector2 Rectangle

10. Let’s move the ball and paddles Update() // Move ball and make it bounce at boundaries. theBall.position += theBall.motion; if (theBall.position.X = SCREEN_WIDTH) theBall.motion = new Vector2(theBall.motion.X, theBall.motion.Y); // reverse X direction if (theBall.position.Y = SCREEN_HEIGHT - theBall.Height) theBall.motion = new Vector2(theBall.motion.X, - theBall.motion.Y);

11. Let’s move the ball and paddles Update() paddle1.position += paddle1.motion; if (paddle1.position.Y <= 0) { // Don’t let it go beyond screen. paddle1.position = new Vector2(paddle1.position.X, 0); paddle1.motion = new Vector2(paddle1.motion.X, -paddle1.motion.Y) } if (paddle1.position.Y >= SCREEN_HEIGHT-paddle1.Height) paddle1.position = new Vector2(0, SCREEN_HEIGHT - paddle1.Height); paddle2.position += paddle2.motion; if (paddle2.position.Y <= 0) { paddle2.position = new Vector2(paddle2.position.X, 0); paddle2.motion = new Vector2(paddle2.motion.X, -paddle2.motion.Y); } if (paddle2.position.Y >= SCREEN_HEIGHT - paddle2.Height) { paddle2.position = new Vector2(paddle2.position.X, SCREEN_HEIGHT - paddle2.Height); paddle2.motion = new Vector2(paddle2.motion.X, -paddle2.motion.Y); } This code looks very similar. Begs for a convenience function Compile and run

12. Lets add sound Solution Explorer Content Add -> New folder Name it sound or audio Right click on your new folder Add -> existing item Browse for a sound file you’d like to use, search for.wav I used ding.wav Also find sounds from the web Can use audacity to make and record them

13. Without using XACT Declare variable. SoundEffect hitWallSound; LoadContent() ContentManager contentManager = new ContentManager(this.Services, @"Content\sound\"); hitWallSound = contentManager.Load ("ding"); Everytime ball hits a wall (in your update) if (theBall.position.Y <= 0 || … ){ hitWallSound.Play(); theBall.motion = new Vector2(X, -Y); } Compile and run

14. Collide ball with paddle(s) In update() if (CollisionWithPaddle()) { hitPaddleSound.play(); theBall.motion = new Vector2( theBall.motion.X*1.03f, theBall.motion.Y*1.03f); } Speed up by 3% each hit

15. CollisionWithPaddle() private bool CollisionWithPaddle() { if (theBall.motion.X > 0) {//Moving Left must hit player2 return(RectsCollide(paddle2.position.X, paddle2.position.Y, paddle2.Width, paddle2.Height, theBall.position.X, theBall.position.Y,theBall.Width, theBall.Height)); else return(RectsCollide(paddle1.position.X, paddle1.position.Y, paddle1.Width, paddle1.Height, theBall.position.X, theBall.position.Y, theBall.Width, theBall.Height)); }

16. RectsCollide() private bool RectsCollide(float x1, float y1, float w1, float h1, float x2, float y2, float w2, float h2) { if (x2 - w2<= x1 && x1 <= x2 + w2 && y1 - h2 <= y2 && y2 <= y1 + h1) return true; else return false; } This is one way to see if two rectangles overlap. For many collisions you’ll want to do pixel level collisions. Many examples on the web, start with overlapping rectangles, then check for two pixels in the overlap that are not transparent.

17. One player game - update() GamePadState pad1 = GamePad.GetState(PlayerIndex.One); paddle1.motion = new Vector2(0, 0); if (pad1.DPad.Down == ButtonState.Pressed) paddle1.motion = new Vector2(0, 5); if (pad1.DPad.Up == ButtonState.Pressed) paddle1.motion = new Vector2(0,-5); if (pad1.ThumbSticks.Left.Y != 0) paddle1.motion = new Vector2(0,pad1.ThumbSticks.Left.Y*-5.0f); paddle1.position += paddle1.motion; if (paddle1.position.Y <= 0) paddle1.position = new Vector2(paddle1.position.X, 0); if (paddle1.position.Y >= SCREEN_HEIGHT-paddle1.Height) paddle1.position=new Vector2(0,SCREEN_HEIGHT- paddle1.Height); arrow pad or the left thumb stick will move paddle. Could add keyboard arrow keys. KeyboardState keyboard = Keyboard.GetState(); keyboard.IsKeyDown(Keys.Up) Don’t allow paddle to go past borders Compile and run Can add AI for other player or paddle2.Height = 356;

18. Score Solution Explorer Content (right click) Add -> New Item Sprite Font Change name to Courier New.spritefont This name is what you want to call it in the program Now in the editor, edit the XML to your desire Change the fontname to Courier New or whatever you want, you can look in control panel for available fonts. Change the size to 32 for this example Can change anything else you want

19. Score Create a type and declare some variables public class Aplayer { private int _score = 0; public int Score { get { return _score; } set { _score = value; } } } APlayer player1; APlayer player2; In initialize() player1 = new APlayer(); player2 = new APlayer();

20. Score - Update() if (theBall.position.X = SCREEN_WIDTH) // Someone has scored! { PlayWallHit(); if (theBall.motion.X < 0) player2.Score++; else player1.Score++; float L = theBall.motion.Length(); theBall.motion *= new Vector2(-3.0f/L, 3.0f/L); theBall.position = new Vector2(320, theBall.position.Y); // Start ball in the middle } Can’t just call normalize() since position is a struct and not a class.

21. Score Declare some variables SpriteFont Font1; Font1 = Content.Load ("Courier New"); Vector2 score1Pos; score1Pos = new Vector2(30,30) // Initialize Draw score spriteBatch.DrawString(Font1, player1.Score.ToString(), score1Pos, Color.White, 0, Vector2.Zero, 1.0f, SpriteEffects.None, 0.5f); If you want to center about point Vector2 FontOrigin = Font1.MeasureString(score) / 2; spriteBatch.DrawString(Font1, score, score1Pos, Color.White, 0, FontOrigin, 1.0f, SpriteEffects.None, 0.5f);

22. Now What Winning game Adding paddle momentum Make paddle curved so edge bounces different Use reflect() from Vector2 and just change the normal AI for the 2 nd user Add two player game, menu to select number of users Three player game? Four player game? Catch ball? Power ups?