Break Out Windows Phone Dev Collision Detection

Question

I was following a tutorial for an XNA Break Out clone which I'm programming for the Windows Phone. The tutorial ends before the collision detection for the ball and bricks is complete. The bricks are put on the screen in rows and columns. I got the bounding box detection for the paddle which reflects the ball off the paddle, but the bricks need the same capability. I'm pasting the code for my main game class, the ball and bricks. If anyone can give me an idea how I can accomplish this it would be greatly appreciated. Do I need a array of rectangles, or is there a different approach to making this work?

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.Input.Touch;
using Microsoft.Xna.Framework.Media;

namespace bouncingBlocks
{
/// <summary>
/// This is the main type for your game
/// </summary>
public class Game1 : Microsoft.Xna.Framework.Game
{
    GraphicsDeviceManager graphics;
    SpriteBatch spriteBatch;
    Texture2D texture1;
    Texture2D texture2;

    public Vector2 spritePosition1;
    Vector2 spritePosition2;
    Texture2D mainBackground;
    Vector2 mainBackgroundPos;
    Vector2 spriteSpeed1 = new Vector2(50.0f, 50.0f);
    Vector2 spriteSpeed2 = new Vector2(100.0f, 100.0f);
    int sprite1Height;
    int sprite1Width;
    int sprite2Height;
    int sprite2Width;
    Texture2D paddleTexture;
    Rectangle screenRectangle;

    int bricksWide;
    int bricksHigh;
    Texture2D brickImage;
    Block[,] bricks;

    Vector2 ballPos;

    SoundEffect soundEffect;

    //objects
    paddle paddle;

    public Game1()
    {
        graphics = new GraphicsDeviceManager(this);
        Content.RootDirectory = "Content";
        graphics.PreferredBackBufferWidth = 320; 
        graphics.PreferredBackBufferHeight = 480;

        screenRectangle = new Rectangle(
            0,
            0,
            graphics.PreferredBackBufferWidth,
            graphics.PreferredBackBufferHeight
            );



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

    /// <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
        TouchPanel.EnabledGestures = GestureType.FreeDrag;


        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);
        spriteBatch = new SpriteBatch(GraphicsDevice);

        texture1 = Content.Load<Texture2D>("Ball");
        texture2 = Content.Load<Texture2D>("Ball");

        mainBackground = Content.Load<Texture2D>("Background");
        mainBackgroundPos.X = 0;
        mainBackgroundPos.Y = 0;
        paddleTexture = Content.Load<Texture2D>("GlowPaddle");
        paddle = new paddle(paddleTexture, screenRectangle);

        brickImage = Content.Load<Texture2D>("BlueBlock");
        bricksWide = 4;
        bricksHigh = 2;

        soundEffect = Content.Load<SoundEffect>("Windows Ding");

        spritePosition1.X = 0;
        spritePosition1.Y = 0;

        spritePosition2.X = graphics.GraphicsDevice.Viewport.Width - texture1.Width;
        spritePosition2.Y = graphics.GraphicsDevice.Viewport.Height - texture1.Height;

        sprite1Height = texture1.Bounds.Height;
        sprite1Width = texture1.Bounds.Width;

        sprite2Height = texture2.Bounds.Height;
        sprite2Width = texture2.Bounds.Width;
        StartGame();
        // 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
    }


    protected override void Update(GameTime gameTime)
    {
        // Allows the game to exit
        if (GamePad.GetState(PlayerIndex.One).Buttons.Back == ButtonState.Pressed)
            this.Exit();
        if (GamePad.GetState(PlayerIndex.One).Buttons.Back ==
        ButtonState.Pressed)
            this.Exit();

        // Move the sprite around.
        UpdateSprite(gameTime, ref spritePosition1, ref spriteSpeed1);
        UpdateSprite(gameTime, ref spritePosition2, ref spriteSpeed2);

        CheckForCollision();
        paddCollision(paddle.GetBounds());



        paddle.Update();



        // TODO: Add your update logic here

        base.Update(gameTime);
    }

    public Rectangle BallGetBounds()
    {
        return new Rectangle(
            (int)spritePosition1.X,
            (int)spritePosition1.Y,
            texture1.Width,
            texture1.Height);
    }

    private void StartGame()
    {

        paddle.SetInStartPosition();

        bricks = new Block[bricksWide, bricksHigh];
        for (int y = 0; y < bricksHigh; y++)
        {
            Color tint = Color.White;
            switch (y)
            {
                case 0:
                    tint = Color.Blue;
                    break;
                case 1:
                    tint = Color.Red;
                    break;
                case 2:
                    tint = Color.Green;
                    break;
                case 3:
                    tint = Color.Yellow;
                    break;
                case 4:
                    tint = Color.Purple;
                    break;
            }
            for (int x = 0; x < bricksWide; x++)
            {
                bricks[x, y] = new Block(
                brickImage,
                new Rectangle(
                x * brickImage.Width,
                y * brickImage.Height,
                brickImage.Width,
                brickImage.Height),
                tint);
            }
        }
    }


    public void blockCollision(Rectangle ballRec)
    {

        Rectangle newballLocation = new Rectangle(
            (int)spritePosition1.X,
            (int)spritePosition1.Y,
            texture1.Width,
            texture1.Height);
        if (ballRec.Intersects(newballLocation))
        {
            spritePosition1.Y = ballRec.Y - texture1.Height;
            spriteSpeed1.Y *= -1;

        }
    }

    public void paddCollision(Rectangle paddleRec)
    {
        Rectangle ballLocation = new Rectangle(
            (int)spritePosition1.X,
            (int)spritePosition1.Y,
            texture1.Width,
            texture1.Height);
        if (paddleRec.Intersects(ballLocation))
        {

            spritePosition1.Y = paddleRec.Y - texture1.Height;
            spriteSpeed1.Y *= -1;
        }
    }

    /// <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.Black);


        spriteBatch.Begin();
        spriteBatch.Draw(mainBackground, mainBackgroundPos, Color.White);


        spriteBatch.End();

        spriteBatch.Begin();
        foreach (Block brick in bricks)
            brick.Draw(spriteBatch);
        paddle.Draw(spriteBatch);
        spriteBatch.End();

        // Draw the sprite.
        spriteBatch.Begin(SpriteSortMode.BackToFront, BlendState.AlphaBlend);

        spriteBatch.Draw(texture1, spritePosition1, Color.White);
        spriteBatch.End();

        spriteBatch.Begin(SpriteSortMode.BackToFront, BlendState.Opaque);
        spriteBatch.Draw(texture2, spritePosition2, Color.Gray);
        spriteBatch.End();

        // TODO: Add your drawing code here

        base.Draw(gameTime);
    }

    void UpdateSprite(GameTime gameTime, ref Vector2 spritePosition, ref Vector2 spriteSpeed)
    {
        // Move the sprite by speed, scaled by elapsed time.
        spritePosition +=
            spriteSpeed * (float)gameTime.ElapsedGameTime.TotalSeconds;

        int MaxX =
            graphics.GraphicsDevice.Viewport.Width - texture1.Width;
        int MinX = 0;
        int MaxY =
            graphics.GraphicsDevice.Viewport.Height - texture1.Height;
        int MinY = 0;

        // Check for bounce.
        if (spritePosition.X > MaxX)
        {
            spriteSpeed.X *= -1;
            spritePosition.X = MaxX;
        }

        else if (spritePosition.X < MinX)
        {
            spriteSpeed.X *= -1;
            spritePosition.X = MinX;
        }

        if (spritePosition.Y > MaxY)
        {
            spriteSpeed.Y *= -1;
            spritePosition.Y = MaxY;
        }

        else if (spritePosition.Y < MinY)
        {
            spriteSpeed.Y *= -1;
            spritePosition.Y = MinY;
        }

    }

    void CheckForCollision()
    {
        BoundingBox bb1 = new BoundingBox(new Vector3(spritePosition1.X - (sprite1Width / 2), 
    spritePosition1.Y - (sprite1Height / 2), 0), new Vector3(spritePosition1.X + (sprite1Width / 2),   
    spritePosition1.Y + (sprite1Height / 2), 0));

        BoundingBox bb2 = new BoundingBox(new Vector3(spritePosition2.X - (sprite2Width / 2),


   spritePosition2.Y - (sprite2Height / 2), 0), new Vector3(spritePosition2.X + (sprite2Width / 2),  
   spritePosition2.Y + (sprite2Height / 2), 0));

        if (bb1.Intersects(bb2))
        {
            soundEffect.Play();
        }

    }

  }
  }

////Block Class

             using System;
        using System.Collections.Generic;
        using System.Linq;
        using System.Text;

        using Microsoft.Xna.Framework;
        using Microsoft.Xna.Framework.Graphics;

        namespace bouncingBlocks
        {
            class Block
            {
                Texture2D texture;
                Rectangle location;
                Color tint;
                bool alive;
                private Texture2D brickImage;
                private Rectangle rectangle;

                Rectangle BallRec;

                public Block(Texture2D brickImage, Rectangle rectangle, Color tint)
                {
                    // TODO: Complete member initialization
                    this.texture = brickImage;
                    this.location = rectangle;
                    this.tint = tint;
                    this.alive = true;


                }
                public Rectangle Location
                {
                    get { return location; }
                }


            public void CheckCollision()
            {

            }

                public void Draw(SpriteBatch spriteBatch)
                {
                    if (alive)
                        spriteBatch.Draw(texture, location, tint);
                }

            }



        }

//Ball Class

        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.Input.Touch;
        using Microsoft.Xna.Framework.Media;

        namespace bouncingBlocks
        {
            class Ball
            {

                Texture2D texture1;
                Texture2D texture2;
                int sprite1Height;
                int sprite1Width;
                public Vector2 spritePosition1;

                Vector2 spriteSpeed1 = new Vector2(50.0f, 50.0f);


                public Ball()
                {

                }
            }
        }

David Jazbec David Jazbec · Accepted Answer · 2012-02-05T23:37:11

If you know position and dimensions of brick you can simply add property wich returns BoudingBox to Brick class. You could also add that property to ball. (BoundingSphere instead of BoundingBox)

  public BoundingBox Boundingbox
  {
      return new BoundingBox(new Vector3(this.position.X, position.Y, 0f),
                             new Vector3(this.position.X + spritewidth,position.Y+spriteheight, 0f));
  }

Then when you check for collitions it would look something like this.

    foreach(Brick b in bricks)
    {
       if(ball.BoundingSphere.Intersects(b.Boundingbox))
       {
           b.Alive=false;
       }
    }

Break Out Windows Phone Dev Collision Detection

1 Answers