// Copyright (c) 2014 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
(function() {
'use strict';
/**
* T-Rex runner.
* @param {string} outerContainerId Outer containing element id.
* @param {object} opt_config
* @constructor
* @export
*/
function Runner(outerContainerId, opt_config) {
// Singleton
if (Runner.instance_) {
return Runner.instance_;
}
Runner.instance_ = this;
this.outerContainerEl = document.querySelector(outerContainerId);
this.containerEl = null;
this.config = opt_config || Runner.config;
this.dimensions = Runner.defaultDimensions;
this.canvas = null;
this.canvasCtx = null;
this.tRex = null;
this.distanceMeter = null;
this.distanceRan = 0;
this.highestScore = 0;
this.time = 0;
this.runningTime = 0;
this.msPerFrame = 1000 / FPS;
this.currentSpeed = this.config.SPEED;
this.obstacles = [];
this.started = false;
this.activated = false;
this.crashed = false;
this.paused = false;
this.resizeTimerId_ = null;
this.playCount = 0;
// Sound FX.
this.audioBuffer = null;
this.soundFx = {};
// Global web audio context for playing sounds.
this.audioContext = new AudioContext();
// Images.
this.images = {};
this.imagesLoaded = 0;
this.loadImages();
}
window['Runner'] = Runner;
/**
* Default game width.
* @const
*/
var DEFAULT_WIDTH = 600;
/**
* Frames per second.
* @const
*/
var FPS = 60;
/** @const */
var IS_HIDPI = window.devicePixelRatio > 1;
/** @const */
var IS_MOBILE = window.navigator.userAgent.indexOf('Mobi') > -1;
/** @const */
var IS_TOUCH_ENABLED = 'ontouchstart' in window;
/**
* Default game configuration.
* @enum {number}
*/
Runner.config = {
ACCELERATION: 0.001,
BG_CLOUD_SPEED: 0.2,
BOTTOM_PAD: 10,
CLEAR_TIME: 3000,
CLOUD_FREQUENCY: 0.5,
GAMEOVER_CLEAR_TIME: 750,
GAP_COEFFICIENT: 0.6,
GRAVITY: 0.6,
INITIAL_JUMP_VELOCITY: 12,
MAX_CLOUDS: 6,
MAX_OBSTACLE_LENGTH: 3,
MAX_SPEED: 12,
MIN_JUMP_HEIGHT: 35,
MOBILE_SPEED_COEFFICIENT: 1.2,
RESOURCE_TEMPLATE_ID: 'audio-resources',
SPEED: 6,
SPEED_DROP_COEFFICIENT: 3
};
/**
* Default dimensions.
* @enum {string}
*/
Runner.defaultDimensions = {
WIDTH: DEFAULT_WIDTH,
HEIGHT: 150
};
/**
* CSS class names.
* @enum {string}
*/
Runner.classes = {
CANVAS: 'runner-canvas',
CONTAINER: 'runner-container',
CRASHED: 'crashed',
ICON: 'icon-offline',
TOUCH_CONTROLLER: 'controller'
};
/**
* Image source urls.
* @enum {array.<object>}
*/
Runner.imageSources = {
LDPI: [
{name: 'CACTUS_LARGE', id: '1x-obstacle-large'},
{name: 'CACTUS_SMALL', id: '1x-obstacle-small'},
{name: 'CLOUD', id: '1x-cloud'},
{name: 'HORIZON', id: '1x-horizon'},
{name: 'RESTART', id: '1x-restart'},
{name: 'TEXT_SPRITE', id: '1x-text'},
{name: 'TREX', id: '1x-trex'}
],
HDPI: [
{name: 'CACTUS_LARGE', id: '2x-obstacle-large'},
{name: 'CACTUS_SMALL', id: '2x-obstacle-small'},
{name: 'CLOUD', id: '2x-cloud'},
{name: 'HORIZON', id: '2x-horizon'},
{name: 'RESTART', id: '2x-restart'},
{name: 'TEXT_SPRITE', id: '2x-text'},
{name: 'TREX', id: '2x-trex'}
]
};
/**
* Sound FX. Reference to the ID of the audio tag on interstitial page.
* @enum {string}
*/
Runner.sounds = {
BUTTON_PRESS: 'offline-sound-press',
HIT: 'offline-sound-hit',
SCORE: 'offline-sound-reached'
};
/**
* Key code mapping.
* @enum {object}
*/
Runner.keycodes = {
JUMP: {'38': 1, '32': 1}, // Up, spacebar
DUCK: {'40': 1}, // Down
RESTART: {'13': 1} // Enter
};
/**
* Runner event names.
* @enum {string}
*/
Runner.events = {
ANIM_END: 'webkitAnimationEnd',
CLICK: 'click',
KEYDOWN: 'keydown',
KEYUP: 'keyup',
MOUSEDOWN: 'mousedown',
MOUSEUP: 'mouseup',
RESIZE: 'resize',
TOUCHEND: 'touchend',
TOUCHSTART: 'touchstart',
VISIBILITY: 'visibilitychange',
BLUR: 'blur',
FOCUS: 'focus',
LOAD: 'load'
};
Runner.prototype = {
/**
* Setting individual settings for debugging.
* @param {string} setting
* @param {*} value
*/
updateConfigSetting: function(setting, value) {
if (setting in this.config && value != undefined) {
this.config[setting] = value;
switch (setting) {
case 'GRAVITY':
case 'MIN_JUMP_HEIGHT':
case 'SPEED_DROP_COEFFICIENT':
this.tRex.config[setting] = value;
break;
case 'INITIAL_JUMP_VELOCITY':
this.tRex.setJumpVelocity(value);
break;
case 'SPEED':
this.setSpeed(value);
break;
}
}
},
/**
* Load and cache the image assets from the page.
*/
loadImages: function() {
var imageSources = IS_HIDPI ? Runner.imageSources.HDPI :
Runner.imageSources.LDPI;
var numImages = imageSources.length;
for (var i = numImages - 1; i >= 0; i--) {
var imgSource = imageSources[i];
this.images[imgSource.name] = document.getElementById(imgSource.id);
}
this.init();
},
/**
* Load and decode base 64 encoded sounds.
*/
loadSounds: function() {
var resourceTemplate =
document.getElementById(this.config.RESOURCE_TEMPLATE_ID).content;
for (var sound in Runner.sounds) {
var soundSrc = resourceTemplate.getElementById(Runner.sounds[sound]).src;
soundSrc = soundSrc.substr(soundSrc.indexOf(',') + 1);
var buffer = decodeBase64ToArrayBuffer(soundSrc);
// Async, so no guarantee of order in array.
this.audioContext.decodeAudioData(buffer, function(index, audioData) {
this.soundFx[index] = audioData;
}.bind(this, sound));
}
},
/**
* Sets the game speed. Adjust the speed accordingly if on a smaller screen.
* @param {number} opt_speed
*/
setSpeed: function(opt_speed) {
var speed = opt_speed || this.currentSpeed;
// Reduce the speed on smaller mobile screens.
if (this.dimensions.WIDTH < DEFAULT_WIDTH) {
var mobileSpeed = speed * this.dimensions.WIDTH / DEFAULT_WIDTH *
this.config.MOBILE_SPEED_COEFFICIENT;
this.currentSpeed = mobileSpeed > speed ? speed : mobileSpeed;
} else if (opt_speed) {
this.currentSpeed = opt_speed;
}
},
/**
* Game initialiser.
*/
init: function() {
// Hide the static icon.
document.querySelector('.' + Runner.classes.ICON).style.visibility =
'hidden';
this.adjustDimensions();
this.setSpeed();
this.containerEl = document.createElement('div');
this.containerEl.className = Runner.classes.CONTAINER;
// Player canvas container.
this.canvas = createCanvas(this.containerEl, this.dimensions.WIDTH,
this.dimensions.HEIGHT, Runner.classes.PLAYER);
this.canvasCtx = this.canvas.getContext('2d');
this.canvasCtx.fillStyle = '#f7f7f7';
this.canvasCtx.fill();
Runner.updateCanvasScaling(this.canvas);
// Horizon contains clouds, obstacles and the ground.
this.horizon = new Horizon(this.canvas, this.images, this.dimensions,
this.config.GAP_COEFFICIENT);
// Distance meter
this.distanceMeter = new DistanceMeter(this.canvas,
this.images.TEXT_SPRITE, this.dimensions.WIDTH);
// Draw t-rex
this.tRex = new Trex(this.canvas, this.images.TREX);
this.outerContainerEl.appendChild(this.containerEl);
if (IS_MOBILE) {
this.createTouchController();
}
this.startListening();
this.update();
this.loadSounds();
window.addEventListener(Runner.events.RESIZE,
this.debounceResize.bind(this), false);
},
/**
* Create the touch controller. A div that covers whole screen.
*/
createTouchController: function() {
this.touchController = document.createElement('div');
this.touchController.className = Runner.classes.TOUCH_CONTROLLER;
},
/**
* Debounce the resize event.
*/
debounceResize: function() {
if (!this.resizeTimerId_) {
this.resizeTimerId_ =
setInterval(this.adjustDimensions.bind(this), 250);
}
},
/**
* Adjust game space dimensions on resize.
*/
adjustDimensions: function() {
clearInterval(this.resizeTimerId_);
this.resizeTimerId_ = null;
var boxStyles = window.getComputedStyle(this.outerContainerEl);
var padding = Number(boxStyles.paddingLeft.substr(0,
boxStyles.paddingLeft.length - 2));
this.dimensions.WIDTH = this.outerContainerEl.offsetWidth - padding * 2;
// Redraw the elements back onto the canvas.
if (this.canvas) {
this.canvas.width = this.dimensions.WIDTH;
this.canvas.height = this.dimensions.HEIGHT;
Runner.updateCanvasScaling(this.canvas);
this.distanceMeter.calcXPos(this.dimensions.WIDTH);
this.clearCanvas();
this.horizon.update(0, 0, true);
this.tRex.update(0);
// Outer container and distance meter.
if (this.activated || this.crashed) {
this.containerEl.style.width = this.dimensions.WIDTH + 'px';
this.containerEl.style.height = this.dimensions.HEIGHT + 'px';
this.distanceMeter.update(0, Math.ceil(this.distanceRan));
this.stop();
} else {
this.tRex.draw(0, 0);
}
// Game over panel.
if (this.crashed && this.gameOverPanel) {
this.gameOverPanel.updateDimensions(this.dimensions.WIDTH);
this.gameOverPanel.draw();
}
}
},
/**
* Play the game intro.
* Canvas container width expands out to the full width.
*/
playIntro: function() {
if (!this.started && !this.crashed) {
this.playingIntro = true;
this.tRex.playingIntro = true;
// CSS animation definition.
var keyframes = '@-webkit-keyframes intro { ' +
'from { width:' + Trex.config.WIDTH + 'px }' +
'to { width: ' + this.dimensions.WIDTH + 'px }' +
'}';
document.styleSheets[0].insertRule(keyframes, 0);
this.containerEl.addEventListener(Runner.events.ANIM_END,
this.startGame.bind(this));
this.containerEl.style.webkitAnimation = 'intro .4s ease-out 1 both';
this.containerEl.style.width = this.dimensions.WIDTH + 'px';
if (this.touchController) {
this.outerContainerEl.appendChild(this.touchController);
}
this.activated = true;
this.started = true;
} else if (this.crashed) {
this.restart();
}
},
/**
* Update the game status to started.
*/
startGame: function() {
this.runningTime = 0;
this.playingIntro = false;
this.tRex.playingIntro = false;
this.containerEl.style.webkitAnimation = '';
this.playCount++;
// Handle tabbing off the page. Pause the current game.
window.addEventListener(Runner.events.VISIBILITY,
this.onVisibilityChange.bind(this), false);
window.addEventListener(Runner.events.BLUR,
this.onVisibilityChange.bind(this), false);
window.addEventListener(Runner.events.FOCUS,
this.onVisibilityChange.bind(this), false);
},
clearCanvas: function() {
this.canvasCtx.clearRect(0, 0, this.dimensions.WIDTH,
this.dimensions.HEIGHT);
},
/**
* Update the game frame.
*/
update: function() {
this.drawPending = false;
var now = performance.now();
var deltaTime = now - (this.time || now);
this.time = now;
if (this.activated) {
this.clearCanvas();
if (this.tRex.jumping) {
this.tRex.updateJump(deltaTime, this.config);
}
this.runningTime += deltaTime;
var hasObstacles = this.runningTime > this.config.CLEAR_TIME;
// First jump triggers the intro.
if (this.tRex.jumpCount == 1 && !this.playingIntro) {
this.playIntro();
}
// The horizon doesn't move until the intro is over.
if (this.playingIntro) {
this.horizon.update(0, this.currentSpeed, hasObstacles);
} else {
deltaTime = !this.started ? 0 : deltaTime;
this.horizon.update(deltaTime, this.currentSpeed, hasObstacles);
}
// Check for collisions.
var collision = hasObstacles &&
checkForCollision(this.horizon.obstacles[0], this.tRex);
if (!collision) {
this.distanceRan += this.currentSpeed * deltaTime / this.msPerFrame;
if (this.currentSpeed < this.config.MAX_SPEED) {
this.currentSpeed += this.config.ACCELERATION;
}
} else {
this.gameOver();
}
if (this.distanceMeter.getActualDistance(this.distanceRan) >
this.distanceMeter.maxScore) {
this.distanceRan = 0;
}
var playAcheivementSound = this.distanceMeter.update(deltaTime,
Math.ceil(this.distanceRan));
if (playAcheivementSound) {
this.playSound(this.soundFx.SCORE);
}
}
if (!this.crashed) {
this.tRex.update(deltaTime);
this.raq();
}
},
/**
* Event handler.
*/
handleEvent: function(e) {
return (function(evtType, events) {
switch (evtType) {
case events.KEYDOWN:
case events.TOUCHSTART:
case events.MOUSEDOWN:
this.onKeyDown(e);
break;
case events.KEYUP:
case events.TOUCHEND:
case events.MOUSEUP:
this.onKeyUp(e);
break;
}
}.bind(this))(e.type, Runner.events);
},
/**
* Bind relevant key / mouse / touch listeners.
*/
startListening: function() {
// Keys.
document.addEventListener(Runner.events.KEYDOWN, this);
document.addEventListener(Runner.events.KEYUP, this);
if (IS_MOBILE) {
// Mobile only touch devices.
this.touchController.addEventListener(Runner.events.TOUCHSTART, this);
this.touchController.addEventListener(Runner.events.TOUCHEND, this);
this.containerEl.addEventListener(Runner.events.TOUCHSTART, this);
} else {
// Mouse.
document.addEventListener(Runner.events.MOUSEDOWN, this);
document.addEventListener(Runner.events.MOUSEUP, this);
}
},
/**
* Remove all listeners.
*/
stopListening: function() {
document.removeEventListener(Runner.events.KEYDOWN, this);
document.removeEventListener(Runner.events.KEYUP, this);
if (IS_MOBILE) {
this.touchController.removeEventListener(Runner.events.TOUCHSTART, this);
this.touchController.removeEventListener(Runner.events.TOUCHEND, this);
this.containerEl.removeEventListener(Runner.events.TOUCHSTART, this);
} else {
document.removeEventListener(Runner.events.MOUSEDOWN, this);
document.removeEventListener(Runner.events.MOUSEUP, this);
}
},
/**
* Process keydown.
* @param {Event} e
*/
onKeyDown: function(e) {
if (!this.crashed && (Runner.keycodes.JUMP[String(e.keyCode)] ||
e.type == Runner.events.TOUCHSTART)) {
if (!this.activated) {
this.activated = true;
}
if (!this.tRex.jumping) {
this.playSound(this.soundFx.BUTTON_PRESS);
this.tRex.startJump();
}
}
if (this.crashed && e.type == Runner.events.TOUCHSTART &&
e.currentTarget == this.containerEl) {
this.restart();
}
// Speed drop, activated only when jump key is not pressed.
if (Runner.keycodes.DUCK[e.keyCode] && this.tRex.jumping) {
e.preventDefault();
this.tRex.setSpeedDrop();
}
},
/**
* Process key up.
* @param {Event} e
*/
onKeyUp: function(e) {
var keyCode = String(e.keyCode);
var isjumpKey = Runner.keycodes.JUMP[keyCode] ||
e.type == Runner.events.TOUCHEND ||
e.type == Runner.events.MOUSEDOWN;
if (this.isRunning() && isjumpKey) {
this.tRex.endJump();
} else if (Runner.keycodes.DUCK[keyCode]) {
this.tRex.speedDrop = false;
} else if (this.crashed) {
// Check that enough time has elapsed before allowing jump key to restart.
var deltaTime = performance.now() - this.time;
if (Runner.keycodes.RESTART[keyCode] ||
(e.type == Runner.events.MOUSEUP && e.target == this.canvas) ||
(deltaTime >= this.config.GAMEOVER_CLEAR_TIME &&
Runner.keycodes.JUMP[keyCode])) {
this.restart();
}
} else if (this.paused && isjumpKey) {
this.play();
}
},
/**
* RequestAnimationFrame wrapper.
*/
raq: function() {
if (!this.drawPending) {
this.drawPending = true;
this.raqId = requestAnimationFrame(this.update.bind(this));
}
},
/**
* Whether the game is running.
* @return {boolean}
*/
isRunning: function() {
return !!this.raqId;
},
/**
* Game over state.
*/
gameOver: function() {
this.playSound(this.soundFx.HIT);
vibrate(200);
this.stop();
this.crashed = true;
this.distanceMeter.acheivement = false;
this.tRex.update(100, Trex.status.CRASHED);
// Game over panel.
if (!this.gameOverPanel) {
this.gameOverPanel = new GameOverPanel(this.canvas,
this.images.TEXT_SPRITE, this.images.RESTART,
this.dimensions);
} else {
this.gameOverPanel.draw();
}
// Update the high score.
if (this.distanceRan > this.highestScore) {
this.highestScore = Math.ceil(this.distanceRan);
this.distanceMeter.setHighScore(this.highestScore);
}
// Reset the time clock.
this.time = performance.now();
},
stop: function() {
this.activated = false;
this.paused = true;
cancelAnimationFrame(this.raqId);
this.raqId = 0;
},
play: function() {
if (!this.crashed) {
this.activated = true;
this.paused = false;
this.tRex.update(0, Trex.status.RUNNING);
this.time = performance.now();
this.update();
}
},
restart: function() {
if (!this.raqId) {
this.playCount++;
this.runningTime = 0;
this.activated = true;
this.crashed = false;
this.distanceRan = 0;
this.setSpeed(this.config.SPEED);
this.time = performance.now();
this.containerEl.classList.remove(Runner.classes.CRASHED);
this.clearCanvas();
this.distanceMeter.reset(this.highestScore);
this.horizon.reset();
this.tRex.reset();
this.playSound(this.soundFx.BUTTON_PRESS);
this.update();
}
},
/**
* Pause the game if the tab is not in focus.
*/
onVisibilityChange: function(e) {
if (document.hidden || document.webkitHidden || e.type == 'blur') {
this.stop();
} else {
this.play();
}
},
/**
* Play a sound.
* @param {SoundBuffer} soundBuffer
*/
playSound: function(soundBuffer) {
if (soundBuffer) {
var sourceNode = this.audioContext.createBufferSource();
sourceNode.buffer = soundBuffer;
sourceNode.connect(this.audioContext.destination);
sourceNode.start(0);
}
}
};
/**
* Updates the canvas size taking into
* account the backing store pixel ratio and
* the device pixel ratio.
*
* See article by Paul Lewis:
* http://www.html5rocks.com/en/tutorials/canvas/hidpi/
*
* @param {HTMLCanvasElement} canvas
* @param {number} opt_width
* @param {number} opt_height
* @return {boolean} Whether the canvas was scaled.
*/
Runner.updateCanvasScaling = function(canvas, opt_width, opt_height) {
var context = canvas.getContext('2d');
// Query the various pixel ratios
var devicePixelRatio = Math.floor(window.devicePixelRatio) || 1;
var backingStoreRatio = Math.floor(context.webkitBackingStorePixelRatio) || 1;
var ratio = devicePixelRatio / backingStoreRatio;
// Upscale the canvas if the two ratios don't match
if (devicePixelRatio !== backingStoreRatio) {
var oldWidth = opt_width || canvas.width;
var oldHeight = opt_height || canvas.height;
canvas.width = oldWidth * ratio;
canvas.height = oldHeight * ratio;
canvas.style.width = oldWidth + 'px';
canvas.style.height = oldHeight + 'px';
// Scale the context to counter the fact that we've manually scaled
// our canvas element.
context.scale(ratio, ratio);
return true;
}
return false;
};
/**
* Get random number.
* @param {number} min
* @param {number} max
* @param {number}
*/
function getRandomNum(min, max) {
return Math.floor(Math.random() * (max - min + 1)) + min;
}
/**
* Vibrate on mobile devices.
* @param {number} duration Duration of the vibration in milliseconds.
*/
function vibrate(duration) {
if (IS_MOBILE) {
window.navigator['vibrate'](duration);
}
}
/**
* Create canvas element.
* @param {HTMLElement} container Element to append canvas to.
* @param {number} width
* @param {number} height
* @param {string} opt_classname
* @return {HTMLCanvasElement}
*/
function createCanvas(container, width, height, opt_classname) {
var canvas = document.createElement('canvas');
canvas.className = opt_classname ? Runner.classes.CANVAS + ' ' +
opt_classname : Runner.classes.CANVAS;
canvas.width = width;
canvas.height = height;
container.appendChild(canvas);
return canvas;
}
/**
* Decodes the base 64 audio to ArrayBuffer used by Web Audio.
* @param {string} base64String
*/
function decodeBase64ToArrayBuffer(base64String) {
var len = (base64String.length / 4) * 3;
var str = atob(base64String);
var arrayBuffer = new ArrayBuffer(len);
var bytes = new Uint8Array(arrayBuffer);
for (var i = 0; i < len; i++) {
bytes[i] = str.charCodeAt(i);
}
return bytes.buffer;
}
//******************************************************************************
/**
* Game over panel.
* @param {!HTMLCanvasElement} canvas
* @param {!HTMLImage} textSprite
* @param {!HTMLImage} restartImg
* @param {!Object} dimensions Canvas dimensions.
* @constructor
*/
function GameOverPanel(canvas, textSprite, restartImg, dimensions) {
this.canvas = canvas;
this.canvasCtx = canvas.getContext('2d');
this.canvasDimensions = dimensions;
this.textSprite = textSprite;
this.restartImg = restartImg;
this.draw();
};
/**
* Dimensions used in the panel.
* @enum {number}
*/
GameOverPanel.dimensions = {
TEXT_X: 0,
TEXT_Y: 13,
TEXT_WIDTH: 191,
TEXT_HEIGHT: 11,
RESTART_WIDTH: 36,
RESTART_HEIGHT: 32
};
GameOverPanel.prototype = {
/**
* Update the panel dimensions.
* @param {number} width New canvas width.
* @param {number} opt_height Optional new canvas height.
*/
updateDimensions: function(width, opt_height) {
this.canvasDimensions.WIDTH = width;
if (opt_height) {
this.canvasDimensions.HEIGHT = opt_height;
}
},
/**
* Draw the panel.
*/
draw: function() {
var dimensions = GameOverPanel.dimensions;
var centerX = this.canvasDimensions.WIDTH / 2;
// Game over text.
var textSourceX = dimensions.TEXT_X;
var textSourceY = dimensions.TEXT_Y;
var textSourceWidth = dimensions.TEXT_WIDTH;
var textSourceHeight = dimensions.TEXT_HEIGHT;
var textTargetX = Math.round(centerX - (dimensions.TEXT_WIDTH / 2));
var textTargetY = Math.round((this.canvasDimensions.HEIGHT - 25) / 3);
var textTargetWidth = dimensions.TEXT_WIDTH;
var textTargetHeight = dimensions.TEXT_HEIGHT;
var restartSourceWidth = dimensions.RESTART_WIDTH;
var restartSourceHeight = dimensions.RESTART_HEIGHT;
var restartTargetX = centerX - (dimensions.RESTART_WIDTH / 2);
var restartTargetY = this.canvasDimensions.HEIGHT / 2;
if (IS_HIDPI) {
textSourceY *= 2;
textSourceX *= 2;
textSourceWidth *= 2;
textSourceHeight *= 2;
restartSourceWidth *= 2;
restartSourceHeight *= 2;
}
// Game over text from sprite.
this.canvasCtx.drawImage(this.textSprite,
textSourceX, textSourceY, textSourceWidth, textSourceHeight,
textTargetX, textTargetY, textTargetWidth, textTargetHeight);
// Restart button.
this.canvasCtx.drawImage(this.restartImg, 0, 0,
restartSourceWidth, restartSourceHeight,
restartTargetX, restartTargetY, dimensions.RESTART_WIDTH,
dimensions.RESTART_HEIGHT);
}
};
//******************************************************************************
/**
* Check for a collision.
* @param {!Obstacle} obstacle
* @param {!Trex} tRex T-rex object.
* @param {HTMLCanvasContext} opt_canvasCtx Optional canvas context for drawing
* collision boxes.
* @return {Array.<CollisionBox>}
*/
function checkForCollision(obstacle, tRex, opt_canvasCtx) {
var obstacleBoxXPos = Runner.defaultDimensions.WIDTH + obstacle.xPos;
// Adjustments are made to the bounding box as there is a 1 pixel white
// border around the t-rex and obstacles.
var tRexBox = new CollisionBox(
tRex.xPos + 1,
tRex.yPos + 1,
tRex.config.WIDTH - 2,
tRex.config.HEIGHT - 2);
var obstacleBox = new CollisionBox(
obstacle.xPos + 1,
obstacle.yPos + 1,
obstacle.typeConfig.width * obstacle.size - 2,
obstacle.typeConfig.height - 2);
// Debug outer box
if (opt_canvasCtx) {
drawCollisionBoxes(opt_canvasCtx, tRexBox, obstacleBox);
}
// Simple outer bounds check.
if (boxCompare(tRexBox, obstacleBox)) {
var collisionBoxes = obstacle.collisionBoxes;
var tRexCollisionBoxes = Trex.collisionBoxes;
// Detailed axis aligned box check.
for (var t = 0; t < tRexCollisionBoxes.length; t++) {
for (var i = 0; i < collisionBoxes.length; i++) {
// Adjust the box to actual positions.
var adjTrexBox =
createAdjustedCollisionBox(tRexCollisionBoxes[t], tRexBox);
var adjObstacleBox =
createAdjustedCollisionBox(collisionBoxes[i], obstacleBox);
var crashed = boxCompare(adjTrexBox, adjObstacleBox);
// Draw boxes for debug.
if (opt_canvasCtx) {
drawCollisionBoxes(opt_canvasCtx, adjTrexBox, adjObstacleBox);
}
if (crashed) {
return [adjTrexBox, adjObstacleBox];
}
}
}
}
return false;
};
/**
* Adjust the collision box.
* @param {!CollisionBox} box The original box.
* @param {!CollisionBox} adjustment Adjustment box.
* @return {CollisionBox} The adjusted collision box object.
*/
function createAdjustedCollisionBox(box, adjustment) {
return new CollisionBox(
box.x + adjustment.x,
box.y + adjustment.y,
box.width,
box.height);
};
/**
* Draw the collision boxes for debug.
*/
function drawCollisionBoxes(canvasCtx, tRexBox, obstacleBox) {
canvasCtx.save();
canvasCtx.strokeStyle = '#f00';
canvasCtx.strokeRect(tRexBox.x, tRexBox.y,
tRexBox.width, tRexBox.height);
canvasCtx.strokeStyle = '#0f0';
canvasCtx.strokeRect(obstacleBox.x, obstacleBox.y,
obstacleBox.width, obstacleBox.height);
canvasCtx.restore();
};
/**
* Compare two collision boxes for a collision.
* @param {CollisionBox} tRexBox
* @param {CollisionBox} obstacleBox
* @return {boolean} Whether the boxes intersected.
*/
function boxCompare(tRexBox, obstacleBox) {
var crashed = false;
var tRexBoxX = tRexBox.x;
var tRexBoxY = tRexBox.y;
var obstacleBoxX = obstacleBox.x;
var obstacleBoxY = obstacleBox.y;
// Axis-Aligned Bounding Box method.
if (tRexBox.x < obstacleBoxX + obstacleBox.width &&
tRexBox.x + tRexBox.width > obstacleBoxX &&
tRexBox.y < obstacleBox.y + obstacleBox.height &&
tRexBox.height + tRexBox.y > obstacleBox.y) {
crashed = true;
}
return crashed;
};
//******************************************************************************
/**
* Collision box object.
* @param {number} x X position.
* @param {number} y Y Position.
* @param {number} w Width.
* @param {number} h Height.
*/
function CollisionBox(x, y, w, h) {
this.x = x;
this.y = y;
this.width = w;
this.height = h;
};
//******************************************************************************
/**
* Obstacle.
* @param {HTMLCanvasCtx} canvasCtx
* @param {Obstacle.type} type
* @param {image} obstacleImg Image sprite.
* @param {Object} dimensions
* @param {number} gapCoefficient Mutipler in determining the gap.
* @param {number} speed
*/
function Obstacle(canvasCtx, type, obstacleImg, dimensions,
gapCoefficient, speed) {
this.canvasCtx = canvasCtx;
this.image = obstacleImg;
this.typeConfig = type;
this.gapCoefficient = gapCoefficient;
this.size = getRandomNum(1, Obstacle.MAX_OBSTACLE_LENGTH);
this.dimensions = dimensions;
this.remove = false;
this.xPos = 0;
this.yPos = this.typeConfig.yPos;
this.width = 0;
this.collisionBoxes = [];
this.gap = 0;
this.init(speed);
};
/**
* Coefficient for calculating the maximum gap.
* @const
*/
Obstacle.MAX_GAP_COEFFICIENT = 1.5;
/**
* Maximum obstacle grouping count.
* @const
*/
Obstacle.MAX_OBSTACLE_LENGTH = 3,
Obstacle.prototype = {
/**
* Initialise the DOM for the obstacle.
* @param {number} speed
*/
init: function(speed) {
this.cloneCollisionBoxes();
// Only allow sizing if we're at the right speed.
if (this.size > 1 && this.typeConfig.multipleSpeed > speed) {
this.size = 1;
}
this.width = this.typeConfig.width * this.size;
this.xPos = this.dimensions.WIDTH - this.width;
this.draw();
// Make collision box adjustments,
// Central box is adjusted to the size as one box.
// ____ ______ ________
// _| |-| _| |-| _| |-|
// | |<->| | | |<--->| | | |<----->| |
// | | 1 | | | | 2 | | | | 3 | |
// |_|___|_| |_|_____|_| |_|_______|_|
//
if (this.size > 1) {
this.collisionBoxes[1].width = this.width - this.collisionBoxes[0].width -
this.collisionBoxes[2].width;
this.collisionBoxes[2].x = this.width - this.collisionBoxes[2].width;
}
this.gap = this.getGap(this.gapCoefficient, speed);
},
/**
* Draw and crop based on size.
*/
draw: function() {
var sourceWidth = this.typeConfig.width;
var sourceHeight = this.typeConfig.height;
if (IS_HIDPI) {
sourceWidth = sourceWidth * 2;
sourceHeight = sourceHeight * 2;
}
// Sprite
var sourceX = (sourceWidth * this.size) * (0.5 * (this.size - 1));
this.canvasCtx.drawImage(this.image,
sourceX, 0,
sourceWidth * this.size, sourceHeight,
this.xPos, this.yPos,
this.typeConfig.width * this.size, this.typeConfig.height);
},
/**
* Obstacle frame update.
* @param {number} deltaTime
* @param {number} speed
*/
update: function(deltaTime, speed) {
if (!this.remove) {
this.xPos -= Math.floor((speed * FPS / 1000) * deltaTime);
this.draw();
if (!this.isVisible()) {
this.remove = true;
}
}
},
/**
* Calculate a random gap size.
* - Minimum gap gets wider as speed increses
* @param {number} gapCoefficient
* @param {number} speed
* @return {number} The gap size.
*/
getGap: function(gapCoefficient, speed) {
var minGap = Math.round(this.width * speed +
this.typeConfig.minGap * gapCoefficient);
var maxGap = Math.round(minGap * Obstacle.MAX_GAP_COEFFICIENT);
return getRandomNum(minGap, maxGap);
},
/**
* Check if obstacle is visible.
* @return {boolean} Whether the obstacle is in the game area.
*/
isVisible: function() {
return this.xPos + this.width > 0;
},
/**
* Make a copy of the collision boxes, since these will change based on
* obstacle type and size.
*/
cloneCollisionBoxes: function() {
var collisionBoxes = this.typeConfig.collisionBoxes;
for (var i = collisionBoxes.length - 1; i >= 0; i--) {
this.collisionBoxes[i] = new CollisionBox(collisionBoxes[i].x,
collisionBoxes[i].y, collisionBoxes[i].width,
collisionBoxes[i].height);
}
}
};
/**
* Obstacle definitions.
* minGap: minimum pixel space betweeen obstacles.
* multipleSpeed: Speed at which multiples are allowed.
*/
Obstacle.types = [
{
type: 'CACTUS_SMALL',
className: ' cactus cactus-small ',
width: 17,
height: 35,
yPos: 105,
multipleSpeed: 3,
minGap: 120,
collisionBoxes: [
new CollisionBox(0, 7, 5, 27),
new CollisionBox(4, 0, 6, 34),
new CollisionBox(10, 4, 7, 14)
]
},
{
type: 'CACTUS_LARGE',
className: ' cactus cactus-large ',
width: 25,
height: 50,
yPos: 90,
multipleSpeed: 6,
minGap: 120,
collisionBoxes: [
new CollisionBox(0, 12, 7, 38),
new CollisionBox(8, 0, 7, 49),
new CollisionBox(13, 10, 10, 38)
]
}
];
//******************************************************************************
/**
* T-rex game character.
* @param {HTMLCanvas} canvas
* @param {HTMLImage} image Character image.
* @constructor
*/
function Trex(canvas, image) {
this.canvas = canvas;
this.canvasCtx = canvas.getContext('2d');
this.image = image;
this.xPos = 0;
this.yPos = 0;
// Position when on the ground.
this.groundYPos = 0;
this.currentFrame = 0;
this.currentAnimFrames = [];
this.blinkDelay = 0;
this.animStartTime = 0;
this.timer = 0;
this.msPerFrame = 1000 / FPS;
this.config = Trex.config;
// Current status.
this.status = Trex.status.WAITING;
this.jumping = false;
this.jumpVelocity = 0;
this.reachedMinHeight = false;
this.speedDrop = false;
this.jumpCount = 0;
this.jumpspotX = 0;
this.init();
};
/**
* T-rex player config.
* @enum {number}
*/
Trex.config = {
DROP_VELOCITY: -5,
GRAVITY: 0.6,
HEIGHT: 47,
INIITAL_JUMP_VELOCITY: -10,
INTRO_DURATION: 1500,
MAX_JUMP_HEIGHT: 30,
MIN_JUMP_HEIGHT: 30,
SPEED_DROP_COEFFICIENT: 3,
SPRITE_WIDTH: 262,
START_X_POS: 50,
WIDTH: 44
};
/**
* Used in collision detection.
* @type {Array.<CollisionBox>}
*/
Trex.collisionBoxes = [
new CollisionBox(1, -1, 30, 26),
new CollisionBox(32, 0, 8, 16),
new CollisionBox(10, 35, 14, 8),
new CollisionBox(1, 24, 29, 5),
new CollisionBox(5, 30, 21, 4),
new CollisionBox(9, 34, 15, 4)
];
/**
* Animation states.
* @enum {string}
*/
Trex.status = {
CRASHED: 'CRASHED',
JUMPING: 'JUMPING',
RUNNING: 'RUNNING',
WAITING: 'WAITING'
};
/**
* Blinking coefficient.
* @const
*/
Trex.BLINK_TIMING = 7000;
/**
* Animation config for different states.
* @enum {object}
*/
Trex.animFrames = {
WAITING: {
frames: [44, 0],
msPerFrame: 1000 / 3
},
RUNNING: {
frames: [88, 132],
msPerFrame: 1000 / 12
},
CRASHED: {
frames: [220],
msPerFrame: 1000 / 60
},
JUMPING: {
frames: [0],
msPerFrame: 1000 / 60
}
};
Trex.prototype = {
/**
* T-rex player initaliser.
* Sets the t-rex to blink at random intervals.
*/
init: function() {
this.blinkDelay = this.setBlinkDelay();
this.groundYPos = Runner.defaultDimensions.HEIGHT - this.config.HEIGHT -
Runner.config.BOTTOM_PAD;
this.yPos = this.groundYPos;
this.minJumpHeight = this.groundYPos - this.config.MIN_JUMP_HEIGHT;
this.draw(0, 0);
this.update(0, Trex.status.WAITING);
},
/**
* Setter for the jump velocity.
* The approriate drop velocity is also set.
*/
setJumpVelocity: function(setting) {
this.config.INIITAL_JUMP_VELOCITY = -setting;
this.config.DROP_VELOCITY = -setting / 2;
},
/**
* Set the animation status.
* @param {!number} deltaTime
* @param {Trex.status} status Optional status to switch to.
*/
update: function(deltaTime, opt_status) {
this.timer += deltaTime;
// Update the status.
if (opt_status) {
this.status = opt_status;
this.currentFrame = 0;
this.msPerFrame = Trex.animFrames[opt_status].msPerFrame;
this.currentAnimFrames = Trex.animFrames[opt_status].frames;
if (opt_status == Trex.status.WAITING) {
this.animStartTime = performance.now();
this.setBlinkDelay();
}
}
// Game intro animation, T-rex moves in from the left.
if (this.playingIntro && this.xPos < this.config.START_X_POS) {
this.xPos += Math.round((this.config.START_X_POS /
this.config.INTRO_DURATION) * deltaTime);
}
if (this.status == Trex.status.WAITING) {
this.blink(performance.now());
} else {
this.draw(this.currentAnimFrames[this.currentFrame], 0);
}
// Update the frame position.
if (this.timer >= this.msPerFrame) {
this.currentFrame = this.currentFrame ==
this.currentAnimFrames.length - 1 ? 0 : this.currentFrame + 1;
this.timer = 0;
}
},
/**
* Draw the t-rex to a particular position.
* @param {number} x
* @param {number} y
*/
draw: function(x, y) {
var sourceX = x;
var sourceY = y;
var sourceWidth = this.config.WIDTH;
var sourceHeight = this.config.HEIGHT;
if (IS_HIDPI) {
sourceX *= 2;
sourceY *= 2;
sourceWidth *= 2;
sourceHeight *= 2;
}
this.canvasCtx.drawImage(this.image, sourceX, sourceY,
sourceWidth, sourceHeight,
this.xPos, this.yPos,
this.config.WIDTH, this.config.HEIGHT);
},
/**
* Sets a random time for the blink to happen.
*/
setBlinkDelay: function() {
this.blinkDelay = Math.ceil(Math.random() * Trex.BLINK_TIMING);
},
/**
* Make t-rex blink at random intervals.
* @param {number} time Current time in milliseconds.
*/
blink: function(time) {
var deltaTime = time - this.animStartTime;
if (deltaTime >= this.blinkDelay) {
this.draw(this.currentAnimFrames[this.currentFrame], 0);
if (this.currentFrame == 1) {
// Set new random delay to blink.
this.setBlinkDelay();
this.animStartTime = time;
}
}
},
/**
* Initialise a jump.
*/
startJump: function() {
if (!this.jumping) {
this.update(0, Trex.status.JUMPING);
this.jumpVelocity = this.config.INIITAL_JUMP_VELOCITY;
this.jumping = true;
this.reachedMinHeight = false;
this.speedDrop = false;
}
},
/**
* Jump is complete, falling down.
*/
endJump: function() {
if (this.reachedMinHeight &&
this.jumpVelocity < this.config.DROP_VELOCITY) {
this.jumpVelocity = this.config.DROP_VELOCITY;
}
},
/**
* Update frame for a jump.
* @param {number} deltaTime
*/
updateJump: function(deltaTime) {
var msPerFrame = Trex.animFrames[this.status].msPerFrame;
var framesElapsed = deltaTime / msPerFrame;
// Speed drop makes Trex fall faster.
if (this.speedDrop) {
this.yPos += Math.round(this.jumpVelocity *
this.config.SPEED_DROP_COEFFICIENT * framesElapsed);
} else {
this.yPos += Math.round(this.jumpVelocity * framesElapsed);
}
this.jumpVelocity += this.config.GRAVITY * framesElapsed;
// Minimum height has been reached.
if (this.yPos < this.minJumpHeight || this.speedDrop) {
this.reachedMinHeight = true;
}
// Reached max height
if (this.yPos < this.config.MAX_JUMP_HEIGHT || this.speedDrop) {
this.endJump();
}
// Back down at ground level. Jump completed.
if (this.yPos > this.groundYPos) {
this.reset();
this.jumpCount++;
}
this.update(deltaTime);
},
/**
* Set the speed drop. Immediately cancels the current jump.
*/
setSpeedDrop: function() {
this.speedDrop = true;
this.jumpVelocity = 1;
},
/**
* Reset the t-rex to running at start of game.
*/
reset: function() {
this.yPos = this.groundYPos;
this.jumpVelocity = 0;
this.jumping = false;
this.update(0, Trex.status.RUNNING);
this.midair = false;
this.speedDrop = false;
this.jumpCount = 0;
}
};
//******************************************************************************
/**
* Handles displaying the distance meter.
* @param {!HTMLCanvasElement} canvas
* @param {!HTMLImage} spriteSheet Image sprite.
* @param {number} canvasWidth
* @constructor
*/
function DistanceMeter(canvas, spriteSheet, canvasWidth) {
this.canvas = canvas;
this.canvasCtx = canvas.getContext('2d');
this.image = spriteSheet;
this.x = 0;
this.y = 5;
this.currentDistance = 0;
this.maxScore = 0;
this.highScore = 0;
this.container = null;
this.digits = [];
this.acheivement = false;
this.defaultString = '';
this.flashTimer = 0;
this.flashIterations = 0;
this.config = DistanceMeter.config;
this.init(canvasWidth);
};
/**
* @enum {number}
*/
DistanceMeter.dimensions = {
WIDTH: 10,
HEIGHT: 13,
DEST_WIDTH: 11
};
/**
* Y positioning of the digits in the sprite sheet.
* X position is always 0.
* @type {array.<number>}
*/
DistanceMeter.yPos = [0, 13, 27, 40, 53, 67, 80, 93, 107, 120];
/**
* Distance meter config.
* @enum {number}
*/
DistanceMeter.config = {
// Number of digits.
MAX_DISTANCE_UNITS: 5,
// Distance that causes achievement animation.
ACHIEVEMENT_DISTANCE: 100,
// Used for conversion from pixel distance to a scaled unit.
COEFFICIENT: 0.025,
// Flash duration in milliseconds.
FLASH_DURATION: 1000 / 4,
// Flash iterations for achievement animation.
FLASH_ITERATIONS: 3
};
DistanceMeter.prototype = {
/**
* Initialise the distance meter to '00000'.
* @param {number} width Canvas width in px.
*/
init: function(width) {
var maxDistanceStr = '';
this.calcXPos(width);
this.maxScore = this.config.MAX_DISTANCE_UNITS;
for (var i = 0; i < this.config.MAX_DISTANCE_UNITS; i++) {
this.draw(i, 0);
this.defaultString += '0';
maxDistanceStr += '9';
}
this.maxScore = parseInt(maxDistanceStr);
},
/**
* Calculate the xPos in the canvas.
* @param {number} canvasWidth
*/
calcXPos: function(canvasWidth) {
this.x = canvasWidth - (DistanceMeter.dimensions.DEST_WIDTH *
(this.config.MAX_DISTANCE_UNITS + 1));
},
/**
* Draw a digit to canvas.
* @param {number} digitPos Position of the digit.
* @param {number} value Digit value 0-9.
* @param {boolean} opt_highScore Whether drawing the high score.
*/
draw: function(digitPos, value, opt_highScore) {
var sourceWidth = DistanceMeter.dimensions.WIDTH;
var sourceHeight = DistanceMeter.dimensions.HEIGHT;
var sourceX = DistanceMeter.dimensions.WIDTH * value;
var targetX = digitPos * DistanceMeter.dimensions.DEST_WIDTH;
var targetY = this.y;
var targetWidth = DistanceMeter.dimensions.WIDTH;
var targetHeight = DistanceMeter.dimensions.HEIGHT;
// For high DPI we 2x source values.
if (IS_HIDPI) {
sourceWidth *= 2;
sourceHeight *= 2;
sourceX *= 2;
}
this.canvasCtx.save();
if (opt_highScore) {
// Left of the current score.
var highScoreX = this.x - (this.config.MAX_DISTANCE_UNITS * 2) *
DistanceMeter.dimensions.WIDTH;
this.canvasCtx.translate(highScoreX, this.y);
} else {
this.canvasCtx.translate(this.x, this.y);
}
this.canvasCtx.drawImage(this.image, sourceX, 0,
sourceWidth, sourceHeight,
targetX, targetY,
targetWidth, targetHeight
);
this.canvasCtx.restore();
},
/**
* Covert pixel distance to a 'real' distance.
* @param {number} distance Pixel distance ran.
* @return {number} The 'real' distance ran.
*/
getActualDistance: function(distance) {
return distance ?
Math.round(distance * this.config.COEFFICIENT) : 0;
},
/**
* Update the distance meter.
* @param {number} deltaTime
* @param {number} distance
* @return {boolean} Whether the acheivement sound fx should be played.
*/
update: function(deltaTime, distance) {
var paint = true;
var playSound = false;
if (!this.acheivement) {
distance = this.getActualDistance(distance);
if (distance > 0) {
// Acheivement unlocked
if (distance % this.config.ACHIEVEMENT_DISTANCE == 0) {
// Flash score and play sound.
this.acheivement = true;
this.flashTimer = 0;
playSound = true;
}
// Create a string representation of the distance with leading 0.
var distanceStr = (this.defaultString +
distance).substr(-this.config.MAX_DISTANCE_UNITS);
this.digits = distanceStr.split('');
} else {
this.digits = this.defaultString.split('');
}
} else {
// Control flashing of the score on reaching acheivement.
if (this.flashIterations <= this.config.FLASH_ITERATIONS) {
this.flashTimer += deltaTime;
if (this.flashTimer < this.config.FLASH_DURATION) {
paint = false;
} else if (this.flashTimer >
this.config.FLASH_DURATION * 2) {
this.flashTimer = 0;
this.flashIterations++;
}
} else {
this.acheivement = false;
this.flashIterations = 0;
this.flashTimer = 0;
}
}
// Draw the digits if not flashing.
if (paint) {
for (var i = this.digits.length - 1; i >= 0; i--) {
this.draw(i, parseInt(this.digits[i]));
}
}
this.drawHighScore();
return playSound;
},
/**
* Draw the high score.
*/
drawHighScore: function() {
this.canvasCtx.save();
this.canvasCtx.globalAlpha = .8;
for (var i = this.highScore.length - 1; i >= 0; i--) {
this.draw(i, parseInt(this.highScore[i], 10), true);
}
this.canvasCtx.restore();
},
/**
* Set the highscore as a array string.
* Position of char in the sprite: H - 10, I - 11.
* @param {number} distance Distance ran in pixels.
*/
setHighScore: function(distance) {
distance = this.getActualDistance(distance);
var highScoreStr = (this.defaultString +
distance).substr(-this.config.MAX_DISTANCE_UNITS);
this.highScore = ['10', '11', ''].concat(highScoreStr.split(''));
},
/**
* Reset the distance meter back to '00000'.
*/
reset: function() {
this.update(0);
this.acheivement = false;
}
};
//******************************************************************************
/**
* Cloud background item.
* Similar to an obstacle object but without collision boxes.
* @param {HTMLCanvasElement} canvas Canvas element.
* @param {Image} cloudImg
* @param {number} containerWidth
*/
function Cloud(canvas, cloudImg, containerWidth) {
this.canvas = canvas;
this.canvasCtx = this.canvas.getContext('2d');
this.image = cloudImg;
this.containerWidth = containerWidth;
this.xPos = containerWidth;
this.yPos = 0;
this.remove = false;
this.cloudGap = getRandomNum(Cloud.config.MIN_CLOUD_GAP,
Cloud.config.MAX_CLOUD_GAP);
this.init();
};
/**
* Cloud object config.
* @enum {number}
*/
Cloud.config = {
HEIGHT: 13,
MAX_CLOUD_GAP: 400,
MAX_SKY_LEVEL: 30,
MIN_CLOUD_GAP: 100,
MIN_SKY_LEVEL: 71,
WIDTH: 46
};
Cloud.prototype = {
/**
* Initialise the cloud. Sets the Cloud height.
*/
init: function() {
this.yPos = getRandomNum(Cloud.config.MAX_SKY_LEVEL,
Cloud.config.MIN_SKY_LEVEL);
this.draw();
},
/**
* Draw the cloud.
*/
draw: function() {
this.canvasCtx.save();
var sourceWidth = Cloud.config.WIDTH;
var sourceHeight = Cloud.config.HEIGHT;
if (IS_HIDPI) {
sourceWidth = sourceWidth * 2;
sourceHeight = sourceHeight * 2;
}
this.canvasCtx.drawImage(this.image, 0, 0,
sourceWidth, sourceHeight,
this.xPos, this.yPos,
Cloud.config.WIDTH, Cloud.config.HEIGHT);
this.canvasCtx.restore();
},
/**
* Update the cloud position.
* @param {number} speed
*/
update: function(speed) {
if (!this.remove) {
this.xPos -= Math.ceil(speed);
this.draw();
// Mark as removeable if no longer in the canvas.
if (!this.isVisible()) {
this.remove = true;
}
}
},
/**
* Check if the cloud is visible on the stage.
* @return {boolean}
*/
isVisible: function() {
return this.xPos + Cloud.config.WIDTH > 0;
}
};
//******************************************************************************
/**
* Horizon Line.
* Consists of two connecting lines. Randomly assigns a flat / bumpy horizon.
* @param {HTMLCanvasElement} canvas
* @param {HTMLImage} bgImg Horizon line sprite.
* @constructor
*/
function HorizonLine(canvas, bgImg) {
this.image = bgImg;
this.canvas = canvas;
this.canvasCtx = canvas.getContext('2d');
this.sourceDimensions = {};
this.dimensions = HorizonLine.dimensions;
this.sourceXPos = [0, this.dimensions.WIDTH];
this.xPos = [];
this.yPos = 0;
this.bumpThreshold = 0.5;
this.setSourceDimensions();
this.draw();
};
/**
* Horizon line dimensions.
* @enum {number}
*/
HorizonLine.dimensions = {
WIDTH: 600,
HEIGHT: 12,
YPOS: 127
};
HorizonLine.prototype = {
/**
* Set the source dimensions of the horizon line.
*/
setSourceDimensions: function() {
for (var dimension in HorizonLine.dimensions) {
if (IS_HIDPI) {
if (dimension != 'YPOS') {
this.sourceDimensions[dimension] =
HorizonLine.dimensions[dimension] * 2;
}
} else {
this.sourceDimensions[dimension] =
HorizonLine.dimensions[dimension];
}
this.dimensions[dimension] = HorizonLine.dimensions[dimension];
}
this.xPos = [0, HorizonLine.dimensions.WIDTH];
this.yPos = HorizonLine.dimensions.YPOS;
},
/**
* Return the crop x position of a type.
*/
getRandomType: function() {
return Math.random() > this.bumpThreshold ? this.dimensions.WIDTH : 0;
},
/**
* Draw the horizon line.
*/
draw: function() {
this.canvasCtx.drawImage(this.image, this.sourceXPos[0], 0,
this.sourceDimensions.WIDTH, this.sourceDimensions.HEIGHT,
this.xPos[0], this.yPos,
this.dimensions.WIDTH, this.dimensions.HEIGHT);
this.canvasCtx.drawImage(this.image, this.sourceXPos[1], 0,
this.sourceDimensions.WIDTH, this.sourceDimensions.HEIGHT,
this.xPos[1], this.yPos,
this.dimensions.WIDTH, this.dimensions.HEIGHT);
},
/**
* Update the x position of an indivdual piece of the line.
* @param {number} pos Line position.
* @param {number} increment
*/
updateXPos: function(pos, increment) {
var line1 = pos;
var line2 = pos == 0 ? 1 : 0;
this.xPos[line1] -= increment;
this.xPos[line2] = this.xPos[line1] + this.dimensions.WIDTH;
if (this.xPos[line1] <= -this.dimensions.WIDTH) {
this.xPos[line1] += this.dimensions.WIDTH * 2;
this.xPos[line2] = this.xPos[line1] - this.dimensions.WIDTH;
this.sourceXPos[line1] = this.getRandomType();
}
},
/**
* Update the horizon line.
* @param {number} deltaTime
* @param {number} speed
*/
update: function(deltaTime, speed) {
var increment = Math.floor(speed * (FPS / 1000) * deltaTime);
if (this.xPos[0] <= 0) {
this.updateXPos(0, increment);
} else {
this.updateXPos(1, increment);
}
this.draw();
},
/**
* Reset horizon to the starting position.
*/
reset: function() {
this.xPos[0] = 0;
this.xPos[1] = HorizonLine.dimensions.WIDTH;
}
};
//******************************************************************************
/**
* Horizon background class.
* @param {HTMLCanvasElement} canvas
* @param {Array.<HTMLImageElement>} images
* @param {object} dimensions Canvas dimensions.
* @param {number} gapCoefficient
* @constructor
*/
function Horizon(canvas, images, dimensions, gapCoefficient) {
this.canvas = canvas;
this.canvasCtx = this.canvas.getContext('2d');
this.config = Horizon.config;
this.dimensions = dimensions;
this.gapCoefficient = gapCoefficient;
this.obstacles = [];
this.horizonOffsets = [0, 0];
this.cloudFrequency = this.config.CLOUD_FREQUENCY;
// Cloud
this.clouds = [];
this.cloudImg = images.CLOUD;
this.cloudSpeed = this.config.BG_CLOUD_SPEED;
// Horizon
this.horizonImg = images.HORIZON;
this.horizonLine = null;
// Obstacles
this.obstacleImgs = {
CACTUS_SMALL: images.CACTUS_SMALL,
CACTUS_LARGE: images.CACTUS_LARGE
};
this.init();
};
/**
* Horizon config.
* @enum {number}
*/
Horizon.config = {
BG_CLOUD_SPEED: 0.2,
BUMPY_THRESHOLD: .3,
CLOUD_FREQUENCY: .5,
HORIZON_HEIGHT: 16,
MAX_CLOUDS: 6
};
Horizon.prototype = {
/**
* Initialise the horizon. Just add the line and a cloud. No obstacles.
*/
init: function() {
this.addCloud();
this.horizonLine = new HorizonLine(this.canvas, this.horizonImg);
},
/**
* @param {number} deltaTime
* @param {number} currentSpeed
* @param {boolean} updateObstacles Used as an override to prevent
* the obstacles from being updated / added. This happens in the
* ease in section.
*/
update: function(deltaTime, currentSpeed, updateObstacles) {
this.runningTime += deltaTime;
this.horizonLine.update(deltaTime, currentSpeed);
this.updateClouds(deltaTime, currentSpeed);
if (updateObstacles) {
this.updateObstacles(deltaTime, currentSpeed);
}
},
/**
* Update the cloud positions.
* @param {number} deltaTime
* @param {number} currentSpeed
*/
updateClouds: function(deltaTime, speed) {
var cloudSpeed = this.cloudSpeed / 1000 * deltaTime * speed;
var numClouds = this.clouds.length;
if (numClouds) {
for (var i = numClouds - 1; i >= 0; i--) {
this.clouds[i].update(cloudSpeed);
}
var lastCloud = this.clouds[numClouds - 1];
// Check for adding a new cloud.
if (numClouds < this.config.MAX_CLOUDS &&
(this.dimensions.WIDTH - lastCloud.xPos) > lastCloud.cloudGap &&
this.cloudFrequency > Math.random()) {
this.addCloud();
}
// Remove expired clouds.
this.clouds = this.clouds.filter(function(obj) {
return !obj.remove;
});
}
},
/**
* Update the obstacle positions.
* @param {number} deltaTime
* @param {number} currentSpeed
*/
updateObstacles: function(deltaTime, currentSpeed) {
// Obstacles, move to Horizon layer.
var updatedObstacles = this.obstacles.slice(0);
for (var i = 0; i < this.obstacles.length; i++) {
var obstacle = this.obstacles[i];
obstacle.update(deltaTime, currentSpeed);
// Clean up existing obstacles.
if (obstacle.remove) {
updatedObstacles.shift();
}
}
this.obstacles = updatedObstacles;
if (this.obstacles.length > 0) {
var lastObstacle = this.obstacles[this.obstacles.length - 1];
if (lastObstacle && !lastObstacle.followingObstacleCreated &&
lastObstacle.isVisible() &&
(lastObstacle.xPos + lastObstacle.width + lastObstacle.gap) <
this.dimensions.WIDTH) {
this.addNewObstacle(currentSpeed);
lastObstacle.followingObstacleCreated = true;
}
} else {
// Create new obstacles.
this.addNewObstacle(currentSpeed);
}
},
/**
* Add a new obstacle.
* @param {number} currentSpeed
*/
addNewObstacle: function(currentSpeed) {
var obstacleTypeIndex =
getRandomNum(0, Obstacle.types.length - 1);
var obstacleType = Obstacle.types[obstacleTypeIndex];
var obstacleImg = this.obstacleImgs[obstacleType.type];
this.obstacles.push(new Obstacle(this.canvasCtx, obstacleType,
obstacleImg, this.dimensions, this.gapCoefficient, currentSpeed));
},
/**
* Reset the horizon layer.
* Remove existing obstacles and reposition the horizon line.
*/
reset: function() {
this.obstacles = [];
this.horizonLine.reset();
},
/**
* Update the canvas width and scaling.
* @param {number} width Canvas width.
* @param {number} height Canvas height.
*/
resize: function(width, height) {
this.canvas.width = width;
this.canvas.height = height;
},
/**
* Add a new cloud to the horizon.
*/
addCloud: function() {
this.clouds.push(new Cloud(this.canvas, this.cloudImg,
this.dimensions.WIDTH));
}
};
})();