javascript谷歌chrome浏览器自带的小恐龙游戏代码

使用方法

var canvas = document.createElement('canvas'),
    a = document.getElementById('runner-container'),
    ctx = canvas.getContext('2d');
canvas.id = 'c';
canvas.width = 600;
canvas.height = 150;
a.appendChild(canvas);

//坐标
var spriteDefinition = {
        CACTUS_LARGE: {
            x: 332,
            y: 2
        }, //大仙人掌
        CACTUS_SMALL: {
            x: 228,
            y: 2
        }, //小仙人掌
        CLOUD: {
            x: 86,
            y: 2
        }, //云
        HORIZON: {
            x: 2,
            y: 54
        }, //地面
        MOON: {
            x: 484,
            y: 2
        }, //月亮
        PTERODACTYL: {
            x: 134,
            y: 2
        }, //翼龙
        RESTART: {
            x: 2,
            y: 2
        }, //重新开始按钮
        TEXT_SPRITE: {
            x: 655,
            y: 2
        }, //分数
        TREX: {
            x: 848,
            y: 2
        }, //霸王龙
        STAR: {
            x: 645,
            y: 2
        } //星星
    },
    FPS = 60,
    DEFAULT_WIDTH = 600,

    imgSprite = document.getElementById('sprite');

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,
    INVERT_FADE_DURATION: 10000, //夜晚持续时间
    INVERT_DISTANCE: 700, //每700距离进行昼夜交替
    MAX_CLOUDS: 6, //云最大数量
    MAX_OBSTACLE_LENGTH: 3,
    MAX_OBSTACLE_DUPLICATION: 2,
    MAX_SPEED: 13,
    MIN_JUMP_HEIGHT: 35,
    MOBILE_SPEED_COEFFICIENT: 1.2,
    RESOURCE_TEMPLATE_ID: 'audio-resources',
    SPEED: 6,
    SPEED_DROP_COEFFICIENT: 3
};
Runner.defaultDimensions = {
    HEIGHT: 150,
    WIDTH: 600
};

Runner.classes = {
    CANVAS: 'runner-canvas',
    CONTAINER: 'runner-container',
    CRASHED: 'crashed',
    ICON: 'icon-offline',
    INVERTED: 'inverted',
    SNACKBAR: 'snackbar',
    SNACKBAR_SHOW: 'snackbar-show',
    TOUCH_CONTROLLER: 'controller'
};

Runner.sounds = {
    BUTTON_PRESS: 'offline-sound-press',
    HIT: 'offline-sound-hit',
    SCORE: 'offline-sound-reached'
};

Runner.keycodes = {
    JUMP: {
        '38': 1,
        '32': 1
    }, // Up, spacebar
    DUCK: {
        '40': 1
    }, // Down
    RESTART: {
        '13': 1
    } // Enter
};

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'
};

function Runner(outerContainerId, opt_config) {
    if (Runner.instance_) {
        return Runner.instance_;
    }
    Runner.instance_ = this;
    //this.outerContainerEl = document.querySelector(outerContainerId);
    this.containerEl = null;
    this.snackbarEl = null;
    //this.detailsButton = this.outerContainerEl.querySelector('#details-button');
    this.config = opt_config || Runner.config;
    this.dimensions = Runner.defaultDimensions;
    this.canvas = null;
    this.ctx = 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 = []; //障碍物

    this.started = false;
    this.activated = false;
    this.crashed = false;
    this.paused = false;
    this.inverted = false;
    this.invertTimer = 0;
    this.resizeTimerId_ = null;

    this.playCount = 0;

    // Sound FX.
    this.audioBuffer = null;
    this.soundFx = {};

    // Global web audio context for playing sounds.
    this.audioContext = null;

    // Images.
    this.images = {};
    this.imagesLoaded = 0;

    this.loadImages();
}

Runner.prototype = {
    loadImages: function() {
        this.spriteDef = spriteDefinition;
        this.init();
    },
    loadSounds: function() {
        this.audioContext = new AudioContext();
    },
    setSpeed: function(opt_speed) {
        if (opt_speed) this.currentSpeed = opt_speed;
    },
    init: function() {
        this.setSpeed();
        this.canvas = c;
        this.ctx = ctx;
        this.ctx.fillStyle = '#f7f7f7';
        this.ctx.fill();

        this.horizon = new Horizon(this.canvas, this.spriteDef, this.dimensions,
            this.config.GAP_COEFFICIENT);

        this.distanceMeter = new DistanceMeter(this.canvas, this.spriteDef.TEXT_SPRITE, this.dimensions.WIDTH);

        this.tRex = new Trex(this.canvas, this.spriteDef.TREX);

        this.startListening();
        this.update();
    },
    //开场动画
    playIntro: function() {
        if (!this.started && !this.crashed) {
            this.playingIntro = true;
            this.tRex.playingIntro = true;

            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 = document.getElementById('runner-container');
            this.containerEl.addEventListener('webkitAnimationEnd',
                this.startGame.bind(this));

            this.containerEl.style.webkitAnimation = 'intro .4s ease-out 1 both';
            this.containerEl.style.width = this.dimensions.WIDTH + 'px';

            this.activated = true;
            this.started = true;
        } else if (this.crashed) {
            this.restart();
        }
    },
    startGame: function() {
        this.runningTime = 0;
        this.playingIntro = false;
        this.tRex.playingIntro = false;
        this.containerEl.style.webkitAnimation = '';
        this.playCount++;

        document.addEventListener('visibilitychange', this.onVisibilityChange.bind(this));
        window.addEventListener('blur', this.onVisibilityChange.bind(this));
        window.addEventListener('focus', this.onVisibilityChange.bind(this));
    },
    clearCanvas: function() {
        this.ctx.clearRect(0, 0, this.dimensions.WIDTH, this.dimensions.HEIGHT);
    },
    //todo
    update: function() {
        this.drawPending = false;

        var now = getTimeStamp();
        var deltaTime = now - (this.time || now);
        this.time = now;

        if (this.activated) {

            this.clearCanvas();

            if (this.tRex.jumping) {
                this.tRex.updateJump(deltaTime);
            }

            this.runningTime += deltaTime;
            var hasObstacles = this.runningTime > this.config.CLEAR_TIME;
            //如果是第一次跳跃并且没有播放开场动画，则播放开场动画
            if (this.tRex.jumpCount == 1 && !this.playingIntro) {
                this.playIntro();
            }

            if (this.playingIntro) {
                this.horizon.update(0, this.currentSpeed, hasObstacles);
            } else {
                deltaTime = !this.started ? 0 : deltaTime;
                this.horizon.update(deltaTime, this.currentSpeed, hasObstacles,
                    this.inverted);
            }
            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();
            }

            var playAchievementSound = this.distanceMeter.update(deltaTime,
                Math.ceil(this.distanceRan));

            if (playAchievementSound) {
                this.playSound(this.soundFx.SCORE);
            }
            //若夜晚持续时间大于设定值则变为白天
            if (this.invertTimer > this.config.INVERT_FADE_DURATION) {
                this.invertTimer = 0;
                this.invertTrigger = false;
                this.invert();
            } else if (this.invertTimer) {
                this.invertTimer += deltaTime;
            } else {
                var actualDistance =
                    this.distanceMeter.getActualDistance(Math.ceil(this.distanceRan));

                if (actualDistance > 0) {
                    this.invertTrigger = !(actualDistance %
                        this.config.INVERT_DISTANCE);

                    if (this.invertTrigger && this.invertTimer === 0) {
                        this.invertTimer += deltaTime;
                        this.invert();
                    }
                }
            }
        }
        if (!this.crashed) {
            this.tRex.update(deltaTime);
            this.raq();
        }
    },
    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);
    },
    startListening: function() {
        document.addEventListener(Runner.events.KEYDOWN, this);
        document.addEventListener(Runner.events.KEYUP, this);
        document.addEventListener(Runner.events.MOUSEDOWN, this);
        document.addEventListener(Runner.events.MOUSEUP, this);
    },
    stopListening: function() {
        document.removeEventListener(Runner.events.KEYDOWN, this);
        document.removeEventListener(Runner.events.KEYUP, this);
        document.removeEventListener(Runner.events.MOUSEDOWN, this);
        document.removeEventListener(Runner.events.MOUSEUP, this);
    },
    onKeyDown: functi