You are previewing Building HTML5 Games with ImpactJS.

Building HTML5 Games with ImpactJS

Cover of Building HTML5 Games with ImpactJS by Jesse Freeman Published by O'Reilly Media, Inc.
  1. Introducing HTML5 Game Development
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  3. A Note Regarding Supplemental Files
  4. Preface
    1. About This Book
    2. Who This Book Is For
    3. Who This Book Is Not For
    4. Conventions Used in This Book
    5. This Book’s Example Files
    6. Using Code Examples
    7. How To Use This Book
    8. Safari® Books Online
    9. How to Contact Us
    10. Acknowledgments
  5. 1. Introduction To Impact
    1. Why Use Impact?
    2. Setting Up a Local Environment
    3. Install WebStorm/PHPStorm
    4. Install Apache/PHP/MySQL
    5. Other Hosting Options
    6. Setting Up a New Impact Project
    7. Modules
    8. How Classes Work
    9. Core Classes
    10. How Inner Classes Work
    11. Level Editor
  6. 2. Working With Sprites
    1. Sprites and Sprite Sheets
    2. Scripting in Photoshop
    3. Working with Sprites in Photoshop
    4. Optimizing Sprites
  7. 3. Introduction To Game Design
    1. What is Game Design?
    2. Sample Game Design Document
      1. Gameplay
      2. Exploring a Map
      3. Combat
      4. Completing a Map
      5. Death
      6. Main Character
      7. Monsters
      8. Bosses
      9. Equipment
      10. Inventory
      11. Equipping Items
      12. Weapons and Armor
      13. Leveling Up
      14. Winning the Game
    3. Coming Up With Ideas
    4. Books to Read
  8. 4. Building A Game
    1. Creating Our First Level
    2. Saving/Loading Maps in Weltmeister
    3. CollisionMaps
    4. The Main Class
    5. Customizing the Main Class
    6. Key Binding
    7. Creating the Player Class
      1. Using Your Sprite Sheet
      2. Adding Simple Physics
      3. Defining Animation Sequences
    8. Creating a Monster Class
    9. Collision Detection
    10. type Property
    11. checkAgainst Property
    12. collides Property
    13. Health
    14. Weapons
    15. Firing the Weapon
    16. Add Multiple Weapons
    17. Killing Entities
    18. Respawning the Player
    19. Create Death Animations
    20. Adding Grenade Explosions
    21. Customizing the Camera
    22. Loading New Levels
  9. 5. Working With Text
    1. Creating Font Sprite Sheets
    2. Adding Text to Your Game
  10. 6. Working With Sound
    1. Adding Sounds
    2. Adding Music
    3. Mobile Browser Sound Compatibility Issues
  11. 7. Creating Game Screens and HUDs
    1. Extending Impact’s Game Class
    2. Creating a Start Screen
    3. Player Stats Screen
    4. Creating the Game Over Screen
    5. Adding In-Game HUD
    6. Game Rewards
    7. In-Game Analytics
  12. 8. Debugging Your Game
    1. Impact’s Debugger
    2. Publishing Your Game
    3. Baking Your Game
    4. Mobile Web Support
    5. Compiling for Native iOS
  13. 9. Wrapping Up
    1. References and Links
  14. About the Author
  15. SPECIAL OFFER: Upgrade this ebook with O’Reilly

Player Stats Screen

Next up, we are going to look at how we can keep track of player stats such as the time it took to complete a level, total number of kills, and how many times the player died. Instead of making this screen a separate game class, we are going to build it into our MyGame class.

We are going to need to add impact.timer to the requires block of our MyGame class. Add the following properties to the MyGame class:

statText: new ig.Font( 'media/04b03.font.png' ),
showStats: false,
statMatte: new ig.Image('media/stat-matte.png'),
levelTimer: new ig.Timer(),
levelExit: null,
stats: {time: 0, kills: 0, deaths: 0},

The following properties will allow us to track the visibility of the stats display, an image we can use to mask the screen, a font, a timer, and a stats object. Next, we are going to need to override the loadLevel() method so we can start a timer to track how long it takes the player to complete the level:

loadLevel: function( data ) {

This basically resets the timer when the main game class has loaded a level. Now in order to display our screen, we have to pause the update loop. The easiest way to do this will be to wrap the call to this.parent() inside update() with a conditional. Here is what the new this.parent() code should look like inside of update():

// Update all entities and BackgroundMaps
        this.showStats = false;
        this.levelExit.nextLevel(); ...

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