Transcript
HTML5 Gameswith CreateJS
TWITTER: @david_kelleherSLIDES: slideshare.net/davekelleher/
Game: davidk.net/game/
Outline
Game TheoryObject Oriented ConceptsHTML5 Game FrameworksCreateJS OverviewCode for Dodgeball GameOther CreateJS FeaturesAtari SDK
Game Theory
Player
UI: Info, Feedback
Decision / Action
Outcome: Win, Loss
Parts of a Web Game
Player
Cartoon character in gym
UI / Feedback
Score (text field) Position of player Balls: position, direction,
speed
Strategy
Dexterity
Luck
Gameplay Decisions/Actions
Decision / Action
Strategy: Avoid or catch ball? Dexterity: Click to “catch” ball
Outcome
Score point for touching clicked (catchable) ball
End game when hit by unclicked ball
Object Oriented
Object Oriented
A procedural coding strategy would have a game loop with a massively complex controller. Use an object oriented coding strategy instead.
Object Oriented
Blinky speeds up as you eat dots
Pinky tends to move counterclockwise
Inky makes unpredictable turns
Clyde doesn’t always chase pac man
Object Oriented
In JavaScript, classes can be defined using the constructor and prototype methods.
Here is use of the constructor:
function MyClass () { var myPrivateVariable; ... this.publicGetVar = function() { return(myPrivateVariable); } ...
Events
User Input• Mouse Move• Click, Mouseup, Mousedown• Drag and Drop, Swipe• Key Input
Game Event• Timer, Tick• Collision (Hit Test)• User Defined
HTML5 Frameworks
Game Frameworks
CreateJS: 2D, like working in FlashPhaser: 2D, more game focusedThreeJS: 3D, large communityBabylon: 3D, more gaming
focused
CreateJS
CreateJS
EaselJS: Core <canvas> featuresTweenJS: Animation librarySoundJS: Audio libraryPreloadJS: Asset manager
CreateJS
Dodgeball Code
Dave’s Dodgeball HTML5
<!DOCTYPE html><html lang="en"><head> <meta charset="utf-8"/> <title>Dodgeball</title> <script src="https://code.createjs.com/easeljs-0.8.0.min.js"> </script> <script src="https://code.createjs.com/tweenjs-0.6.0.min.js"> </script></head><body>
<script src="js/game.js"></script></body></html>
CreateJS Classes Used
EaselJS TweenJS• Stage• Ticker• Bitmap• Text• MouseEvent
• Tween• Ease
Dave’s Dodgeball JS
// Create gym background instancevar gym = new createjs.Bitmap("img/gym.jpg");
Dave’s Dodgeball JS
// Create score instancevar score = new createjs.Text(0, 'bold 50px sans-serif', '#FFF');score.x = 20;score.y = 20;score.value = 0; // custom property// method for scoring a pointscore.point = function () { score.value++; this.text = this.value;}
Dave’s Dodgeball JS
// Create player instancevar player = new createjs.Bitmap("img/player.png");player.x = 232;player.y = 275;player.alive = true; // custom propertyplayer.die = function () { player.alive = false; player.image = new createjs.Bitmap("img/player-dead.png").image;}
Dave’s Dodgeball JS
// Create instances of ball graphicsballCatchable = new createjs.Bitmap("img/ball-catch.png");ballCaught = new createjs.Bitmap("img/star.gif")
Dave’s Dodgeball JS
// Define a Ball "class"function Ball () { var ball = new createjs.Bitmap("img/ball.png"); ball.catchable = false; ball.caught = false; ball.x = Math.floor((Math.random() * 600) + 1); ball.scaleX = .25; ball.scaleY = .25; ball.regX = ball.image.width / 2; ball.regY = ball.image.height / 2;
Dave’s Dodgeball JS
// Ball class continued ...
// Handler for mousedown listener ball.addEventListener("mousedown", function() { ball.image = ballCatchable.image; ball.catchable = true; });
Dave’s Dodgeball JS
// Ball class continued ...
// Handler for tick event listener (HitTest) ball.on("tick", function() { if (this.y<500) { var xDist = this.x - player.x - 70; var yDist = this.y - player.y - 30; // Using pythagorus var distance = Math.sqrt(xDist*xDist + yDist*yDist); if ((distance < 50) && (this.caught == false)) { if ((ball.catchable == true) && (player.alive == true)) { ball.caught = true; ball.image = ballCaught.image; ball.regX = 130; ball.regY = 130; score.point(); } else { player.die(); } } } });
Dave’s Dodgeball JS
// Ball class continued ...
// Move the ball ball.moveToX = Math.floor((Math.random() * 600) + 1); ball.moveTime = Math.floor((Math.random() * 100) + 2000); createjs.Tween.get(ball) .to({scaleX:.75, scaleY:.75, x:ball.moveToX, y:500, rotation:1440}, ball.moveTime, createjs.Ease.getPowOut(1.5) );
Dave’s Dodgeball JS
// Ball class continued ...
// Provide "public" access to the ball object this.getBall = function() { return(ball); }}
Dave’s Dodgeball JS
// Make HTML5 canvas elementvar canvas = document.createElement("canvas");canvas.width = 600;canvas.height = 400;document.body.appendChild(canvas);
Dave’s Dodgeball JS
// Make Create.js stagevar stage = new createjs.Stage(canvas);stage.addChild(gym);stage.addChild(score);stage.addChild(player);// Handler for mousemove listener (player follows mouse)stage.on("stagemousemove", function(evt) { if (player.alive == true) player.x = evt.stageX-68;});stage.mouseMoveOutside = true;
Dave’s Dodgeball JS
// Add a ticker to the stage objectvar tickHandle = createjs.Ticker.on("tick", stage);createjs.Ticker.setFPS(60);
Dave’s Dodgeball JS
// Ticker continued ...
createjs.Ticker.addEventListener("tick", function() { // Add ball instance randomNumber = Math.floor((Math.random() * 60) + 1); if ((randomNumber == 1) && (player.alive == true)) { stage.addChild(new Ball().getBall()); }});
More CreateJS
SpriteSheet
SpriteSheet Classvar data = {
images: ["sprites.jpg"], frames: {width:50,
height:50},animations: {
stand:0, run:[1,5], jump:[6,8,"run"]
}};
Drag and Drop
object.on("pressmove", function(evt) { evt.target.x = evt.stageX; evt.target.y = evt.stageY;});
Atari Arcade SDK
Atari Arcade
https://www.atari.com/arcade/developers
Atari Arcade SDK (extends CreateJS)https://github.com/AtariAdmin/AtariArcadeSDK
HTML5 Gameswith CreateJS
TWITTER: @david_kelleherSLIDES: slideshare.net/davekelleher/
Game: davidk.net/game/
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