Pen Settings

HTML

CSS

CSS Base

Vendor Prefixing

Add External Stylesheets/Pens

Any URLs added here will be added as <link>s in order, and before the CSS in the editor. You can use the CSS from another Pen by using its URL and the proper URL extension.

+ add another resource

JavaScript

Babel includes JSX processing.

Add External Scripts/Pens

Any URL's added here will be added as <script>s in order, and run before the JavaScript in the editor. You can use the URL of any other Pen and it will include the JavaScript from that Pen.

+ add another resource

Packages

Add Packages

Search for and use JavaScript packages from npm here. By selecting a package, an import statement will be added to the top of the JavaScript editor for this package.

Behavior

Auto Save

If active, Pens will autosave every 30 seconds after being saved once.

Auto-Updating Preview

If enabled, the preview panel updates automatically as you code. If disabled, use the "Run" button to update.

Format on Save

If enabled, your code will be formatted when you actively save your Pen. Note: your code becomes un-folded during formatting.

Editor Settings

Code Indentation

Want to change your Syntax Highlighting theme, Fonts and more?

Visit your global Editor Settings.

HTML

              
                <header>0</header>
<div class="difficulty-select">
	<h1>Select Difficulty</h1>
	<button type="button" data-difficulty="0" disabled>Easy</button>
	<button type="button" data-difficulty="1" disabled>Medium</button>
	<button type="button" data-difficulty="2" disabled>Hard</button>
	<button type="button" data-difficulty="3" disabled>Brutal</button>
</div>
<div class="tutorial">
	<p><strong>Steer:</strong></p>
	<p><kbd>A</kbd> <kbd>D</kbd><br>or<br><kbd>&#8592;</kbd> <kbd>&#8594;</kbd><br>or<br>Drag left/right</p>
</div>
<button type="button" class="replay" disabled>
	<svg class="btn-icon" xmlns="http://www.w3.org/2000/svg" x="0px" y="0px" width="96px" height="96px" viewBox="0 0 96 96" enable-background="new 0 0 96 96">
		<path d="M96,88V60c0-1.083-0.396-2.021-1.188-2.812C94.02,56.396,93.083,56,92,56H64c-1.75,0-2.979,0.833-3.688,2.5
c-0.709,1.625-0.418,3.062,0.875,4.312l8.625,8.625C63.645,77.145,56.374,79.999,48,79.999c-4.333,0-8.469-0.844-12.406-2.531
c-3.937-1.687-7.344-3.969-10.219-6.844s-5.156-6.281-6.844-10.219C16.843,56.467,16,52.332,16,47.999
c0-4.334,0.844-8.469,2.531-12.406c1.687-3.937,3.969-7.344,6.844-10.219s6.281-5.156,10.219-6.844
c3.938-1.688,8.073-2.531,12.406-2.531c7.042,0,13.375,2.072,19,6.219c5.625,4.147,9.479,9.595,11.562,16.345
C78.854,39.521,79.479,40,80.438,40h12.438c0.667,0,1.188-0.25,1.562-0.75c0.416-0.541,0.562-1.104,0.438-1.688
c-1.625-7.291-4.698-13.791-9.219-19.5C81.135,12.354,75.594,7.916,69.031,4.75C62.468,1.584,55.458,0,48,0
c-6.5,0-12.708,1.271-18.625,3.812s-11.021,5.959-15.312,10.25s-7.708,9.396-10.25,15.312S0,41.5,0,48s1.271,12.708,3.812,18.625
s5.958,11.021,10.25,15.312s9.396,7.707,15.312,10.25C35.29,94.729,41.5,96,48,96c6.125,0,12.052-1.156,17.781-3.469
c5.729-2.313,10.822-5.573,15.281-9.781l8.125,8.062c1.207,1.291,2.666,1.582,4.375,0.875C95.188,90.979,96,89.75,96,88z"/>
	</svg>
</button>
              
            
!

CSS

              
                * {
	border: 0;
	box-sizing: border-box;
	margin: 0;
	padding: 0;
}
:root {
	font-size: calc(16px + (20 - 16) * (100vw - 320px)/(1024 - 320));
}
body, button {
	color: #fff;
	font: 1em Muli, "Helvetica Neue", Helvetica, sans-serif;
	line-height: 1.5;
}
body {
	overflow: hidden;
}
button, canvas {
	-webkit-tap-highlight-color: transparent;
}
button, .difficulty-select, .tutorial {
	opacity: 0;
}
button {
	background: #2762f3;
	border-radius: 0.375em;
	box-shadow: 0 0 0 0.25em inset, 0 -0.5em 0 #0003 inset;
	cursor: pointer;
	display: block;
	font-weight: 700;
	margin: 0 auto 0.75em auto;
	padding: 0.75em 1.5em;
	transition: background 0.15s linear;
	transform: translateY(50%);
	width: 100%;
	max-width: 16em;
	-webkit-user-select: none;
	-moz-user-select: none;
	-ms-user-select: none;
	user-select: none;
}
button:hover {
	background: #5785f6;
}
button:active {
	background: #0c48db;
}
button:disabled {
	cursor: default;
}
header, .difficulty-select, .tutorial, .replay {
	position: absolute;
	z-index: 1;
}
header, .difficulty-select {
	left: 0;
	width: 100%;
}
header, h1 {
	line-height: 1;
}
header {
	font-size: 4em;
	font-weight: 900;
	top: 0;
	padding: 0.75rem;
	-webkit-text-stroke: 4px #171717;
	text-shadow: 0 4px 0 #171717;
	transform: translateY(-100%);
	transition: all 0.25s linear;
}
h1 {
	font-size: 2em;
	margin-bottom: 1em;
	text-align: center;
	transform: translateX(100%);
}
kbd {
	background: #242424;
	border-radius: 0.25em;
	display: inline-block;
	font-family: Helvetica, sans-serif;
	height: 1.5em;
	min-width: 1.5em;
	padding: 0 0.25em;
	text-align: center;
	vertical-align: middle;
}
p {
	margin-bottom: 1.5em;
}

/* UI */
.difficulty-select, .tutorial, .replay {
	top: 50%;
}
.difficulty-select, .tutorial {
	background: #0000007f;
}
.difficulty-select {
	padding: 1.5em 0;
	transform: translateY(-50%);
}
.menu-active, .tutorial-active, .replay-active {
	z-index: 9;
}
.menu-active {
	animation: fadeIn 0.5s linear forwards;
}
.menu-active h1 {
	animation: slideIn 0.5s 0.5s linear forwards;
}
.menu-active button:nth-of-type(1) {
	animation: fadeSlide 0.15s 1s linear forwards;
}
.menu-active button:nth-of-type(2) {
	animation: fadeSlide 0.15s 1.15s linear forwards;
}
.menu-active button:nth-of-type(3) {
	animation: fadeSlide 0.15s 1.3s linear forwards;
}
.menu-active button:nth-of-type(4) {
	animation: fadeSlide 0.15s 1.45s linear forwards;
}
.menu-inactive {
	animation: fadeIn 0.5s 1.1s linear reverse forwards;
	opacity: 1;
}
.menu-inactive h1 {
	animation: slideOut 0.5s 0.6s linear forwards;
	transform: translateX(0);
}
.menu-inactive button {
	opacity: 1;
	transform: translateY(0);
}
.menu-inactive button:nth-of-type(1) {
	animation: fadeSlide 0.15s linear reverse forwards;
}
.menu-inactive button:nth-of-type(2) {
	animation: fadeSlide 0.15s 0.15s linear reverse forwards;
}
.menu-inactive button:nth-of-type(3) {
	animation: fadeSlide 0.15s 0.3s linear reverse forwards;
}
.menu-inactive button:nth-of-type(4) {
	animation: fadeSlide 0.15s 0.45s linear reverse forwards;
}
.tutorial {
	border-radius: 0.75em;
	padding: 1.5em 1.5em 0 1.5em;
	left: 50%;
	text-align: center;
	width: 12em;
	transform: translate(-50%,-50%);
	transition: opacity 0.25s linear;
}
.replay {
	margin: 0;
	padding: 1.5em;
	left: 50%;
	transform: translate(-50%,0);
	transition: all 0.15s linear;
	width: 6em;
	height: 6em;
}
.btn-icon {
	fill: #fff;
	width: 3em;
	height: 3em;
}
.score-active {
	transform: translateY(0);
}
.tutorial-active, .replay-active {
	opacity: 1;
}
.replay-active {
	transform: translate(-50%,-50%);
}

/* Animations */
@keyframes fadeIn {
	from { opacity: 0 }
	to { opacity: 1 }
}
@keyframes slideIn {
	from { transform: translateX(100%) }
	to { transform: translateX(0) }
}
@keyframes slideOut {
	from { transform: translateX(0) }
	to { transform: translateX(-100%) }
}
@keyframes fadeSlide {
	from {
		opacity: 0;
		transform: translateY(50%);
	}
	to {
		opacity: 1;
		transform: translateY(0);
	}
}
              
            
!

JS

              
                window.addEventListener("DOMContentLoaded",app);

function app() {
	var header = document.querySelector("header"),
		difSelect = document.querySelector(".difficulty-select"),
		difButtons = difSelect.querySelectorAll("button"),
		tutorialBox = document.querySelector(".tutorial"),
		replayButton = document.querySelector(".replay"),

		scene,
		camera,
		renderer,
		hemiLight,
		pointLight,
		touch = {hold: false, x: 0},

		difSelectActive = false,
		scoreCounterActive = false,
		replayBtnActive = false,

		game = null,
		randomInt = (min,max) => Math.round(Math.random() * (max - min)) + min,
		skyColor = 0x69c6d0,
		pointLightZ = -60,
		cameraY = 45,
		cameraYMin = 7,
		renderDistance = 8,
		roadChunks = [];

	class Game {
		constructor(args) {
			// 0: easy, 1: medium (default), 2: hard, 3: brutal
			let d = args.difficulty;
			this.difficulty = d >= 0 && d <= 3 ? d : 1;

			this.tutorial = args.tutorial === true;
			this.over = false;
			this.preparingNew = false;
			this.score = 0;
			this.noScoreXZone = 15;
			this.vehicles = [
				new Vehicle({
					color: 0xff1717,
					x: 0,
					z: 0,
					modelID: 0,
					speed: 1,
					acceleration: 0.001 * 2**d,
					name: "Vehicle 0"
				})
			];
			this.vehicleSpawns = this.vehicles.length;
			this.vehicleLimit = 9;
			this.vehicleIDCtrld = 0;
			this.spark = null;
		}
	}
	class RoadChunk {
		constructor(zSpaces) {
			let chunkSize = 40,
				lineWidth = 1,
				lineHeight = 4,
				dotLines = 3;

			this.chunkSize = chunkSize;
			// surface
			this.surfaceGeo = new THREE.PlaneBufferGeometry(chunkSize,chunkSize);
			this.surfaceMat = new THREE.MeshLambertMaterial({
				color: 0x575757
			});
			this.surface = new THREE.Mesh(this.surfaceGeo,this.surfaceMat);
			this.surface.name = "Road Chunk";
			this.surface.rotation.x = -Math.PI/2;
			this.surface.position.set(0,0,zSpaces*chunkSize);
			this.surface.receiveShadow = true;
			scene.add(this.surface);

			// shoulder lines
			let lineGeo = new THREE.PlaneBufferGeometry(lineWidth,chunkSize),
				lineMat = new THREE.MeshLambertMaterial({
					color: 0xffffff
				}),
				line = new THREE.Mesh(lineGeo,lineMat);
			line.receiveShadow = true;

			let leftShoulder = line.clone();
			leftShoulder.position.set(-chunkSize*0.375,0,0.01);
			this.surface.add(leftShoulder);

			let rightShoulder = line.clone();
			rightShoulder.position.set(chunkSize*0.375,0,0.01);
			this.surface.add(rightShoulder);

			// dotted lines
			let dotLineGeo = new THREE.PlaneBufferGeometry(lineWidth,lineHeight),
				dotLineMat = new THREE.MeshLambertMaterial({
					color: 0xffffff
				}),
				dotLine = new THREE.Mesh(dotLineGeo,dotLineMat);

			for (let l = 0; l < dotLines; ++l) {
				let y = chunkSize/2 - (chunkSize / dotLines) * l - lineHeight/2;

				let leftLine = dotLine.clone();
				leftLine.position.set(-chunkSize*0.125,y,0.01);
				this.surface.add(leftLine);

				let rightLine = dotLine.clone();
				rightLine.position.set(chunkSize*0.125,y,0.01);
				this.surface.add(rightLine);
			}
		}
	}
	class Vehicle {
		constructor(args) {
			this.color = args.color || randomInt(0x171717,0xcccccc);
			this.x = args.x || 0;
			this.z = args.z || 0;
			this.width = 1;
			this.height = 1;
			this.depth = 1;
			this.speed = args.speed || 1;
			this.acceleration = args.acceleration || 0;
			this.model = null;
			this.name = args.name || "";

			this.maxSpeed = 4;
			this.isSteering = false;
			this.steerAngle = 0;
			this.maxSteerAngle = 30;
			this.steerSpeed = 0.15;
			this.steerDir = "";
			this.xLimit = 20;
			this.crashed = false;
			this.deceleration = 0.01;

			// 0: car, 1: truck, 2: tractor trailer
			let modelID = args.modelID;

			if (modelID === undefined)
				modelID = Math.round(Math.random() * 2)

			// dimensions refer to hitbox
			switch (modelID) {
				case 1:
					this.width = 5;
					this.height = 5;
					this.depth = 10;
					this.model = new Truck(this.color,this.x,this.z,this.name); 
					break;
				case 2:
					this.width = 5;
					this.height = 8;
					this.depth = 18;
					this.model = new TractorTrailer(this.color,this.x,this.z,this.name);
					break;
				default:
					this.width = 5;
					this.height = 4;
					this.depth = 10;
					this.model = new Car(this.color,this.x,this.z,this.name);
					break;
			}
		}
		accelerate() {
			if (this.speed < this.maxSpeed) {
				this.speed += this.acceleration;
				this.speed = +(this.speed).toFixed(3);
			}
		}
		decelerate() {
			if (this.speed > 0) {
				this.speed -= this.deceleration;
				this.speed = +(this.speed).toFixed(3);

				if (this.speed < 0)
					this.speed = 0;
			}
		}
		move() {
			let mesh = this.model.mesh;

			// normal forward direction
			this.z -= this.speed;
			mesh.position.z = this.z;

			// handle steering
			if (this.isSteering && !this.crashed) {
				if (this.steerDir == "left") {
					this.x -= this.steerSpeed;

					if (this.steerAngle < this.maxSteerAngle)
						++this.steerAngle;
				}
				else if (this.steerDir == "right") {
					this.x += this.steerSpeed;

					if (this.steerAngle > -this.maxSteerAngle)
						--this.steerAngle;
				}

			// undo steering
			} else if (!this.crashed) {
				if (this.steerAngle > 0) {
					--this.steerAngle;
					this.x -= this.steerSpeed;

				} else if (this.steerAngle < 0) {
					++this.steerAngle;
					this.x += this.steerSpeed;
				}
			}

			// auto crash if out of bounds
			if (this.x < -this.xLimit || this.x > this.xLimit) {
				this.crashed = true;
				game.over = true;
			}

			mesh.position.x = this.x;
			mesh.rotation.y = this.steerAngle * Math.PI/180;

			if (!this.crashed) {
				mesh.getObjectByName("FL").rotation.y = mesh.rotation.y;
				mesh.getObjectByName("FR").rotation.y = mesh.rotation.y;
			}
		}
		steer(dir) {
			this.isSteering = true;
			this.steerDir = dir;
		}
		straighten() {
			this.isSteering = false;
			this.steerDir = "";
		}
	}
	class Car {
		constructor(color,x,z,name) {
			// I. Group
			this.mass = 3;
			this.mesh = new THREE.Object3D();
			this.mesh.name = name;
			this.mesh.position.set(x,2,z);
			scene.add(this.mesh);

			// II. Body
			var carBodyBase = new THREE.Mesh(new THREE.BoxBufferGeometry(5,3,10)),
				cutFront = new THREE.Mesh(new THREE.BoxBufferGeometry(5,1,3)),
				cutBack = new THREE.Mesh(new THREE.BoxBufferGeometry(5,1,2)),
				frontTireHoles = new THREE.Mesh(new THREE.CylinderBufferGeometry(1.2,1.2,5,16,16,false)),
				backTireHoles = frontTireHoles.clone();

			cutFront.position.set(0,1,-3.5);
			cutBack.position.set(0,1,4);

			frontTireHoles.position.set(0,-1.5,-3);
			frontTireHoles.rotation.z = 90 * Math.PI/180;

			backTireHoles.position.set(0,-1.5,3);
			backTireHoles.rotation.z = frontTireHoles.rotation.z;

			carBodyBase.updateMatrix();
			cutFront.updateMatrix();
			cutBack.updateMatrix();
			frontTireHoles.updateMatrix();
			backTireHoles.updateMatrix();

			var carBodyBase_BSP = CSG.fromMesh(carBodyBase),
				cutFront_BSP = CSG.fromMesh(cutFront),
				cutBack_BSP = CSG.fromMesh(cutBack),
				frontTireHoles_BSP = CSG.fromMesh(frontTireHoles),
				backTireHoles_BSP = CSG.fromMesh(backTireHoles),
				carBody_BSP = carBodyBase_BSP
					.subtract(cutFront_BSP)
					.subtract(cutBack_BSP)
					.subtract(frontTireHoles_BSP)
					.subtract(backTireHoles_BSP),
				carBody = CSG.toMesh(carBody_BSP, carBodyBase.matrix);

			carBody.material = new THREE.MeshLambertMaterial({
				color: color
			});
			carBody.position.set(0,0.5,0);
			carBody.castShadow = true;
			this.mesh.add(carBody);

			// III. Wheels
			var wheelGeo = new THREE.CylinderBufferGeometry(1,1,0.5,24,24,false),
				wheelMat = new THREE.MeshLambertMaterial({
					color: 0x171717
				}),
				wheel = new THREE.Mesh(wheelGeo,wheelMat);
			wheel.castShadow = true;
			wheel.rotation.z = -0.5 * Math.PI;

			var wheelPos = [
				{x: -2.25, y: -1, z: 3, name: "BL"},
				{x: 2.25, y: -1, z: 3, name: "BR"},
				{x: -2.25, y: -1, z: -3, name: "FL"},
				{x: 2.25, y: -1, z: -3, name: "FR"}
			];
			for (let p of wheelPos) {
				var w = wheel.clone();
				w.name = p.name;
				w.position.set(p.x,p.y,p.z);
				this.mesh.add(w);
			}

			// IV. Windows
			var windowMat = new THREE.MeshLambertMaterial({
					color: 0x171717
				}),

				horzWindowGeo = new THREE.PlaneBufferGeometry(4.4,0.8),
				horzWindowMat = windowMat,
				horzWindow = new THREE.Mesh(horzWindowGeo,horzWindowMat),

				midFrontWindowGeo = new THREE.PlaneBufferGeometry(2.3,0.8),
				midFrontWindowMat = windowMat,
				midFrontWindow = new THREE.Mesh(midFrontWindowGeo,midFrontWindowMat),

				midBackWindowGeo = new THREE.PlaneBufferGeometry(1.5,0.8),
				midBackWindowMat = windowMat,
				midBackWindow = new THREE.Mesh(midBackWindowGeo,midBackWindowMat);

			horzWindow.receiveShadow = true;
			midFrontWindow.receiveShadow = true;
			midBackWindow.receiveShadow = true;

			var leftMFWindow = midFrontWindow.clone();
			leftMFWindow.position.set(-2.51,1.4,-0.4);
			leftMFWindow.rotation.y = -0.5 * Math.PI;
			this.mesh.add(leftMFWindow);

			var rightMFWindow = midFrontWindow.clone();
			rightMFWindow.position.set(2.51,1.4,-0.4);
			rightMFWindow.rotation.y = 0.5 * Math.PI;
			this.mesh.add(rightMFWindow);

			var leftMBWindow = midBackWindow.clone();
			leftMBWindow.position.set(-2.51,1.4,1.9);
			leftMBWindow.rotation.y = -0.5 * Math.PI;
			this.mesh.add(leftMBWindow);

			var rightMBWindow = midBackWindow.clone();
			rightMBWindow.position.set(2.51,1.4,1.9);
			rightMBWindow.rotation.y = 0.5 * Math.PI;
			this.mesh.add(rightMBWindow);

			var frontWindow = horzWindow.clone();
			frontWindow.position.set(0,1.4,-2.01);
			frontWindow.rotation.y = Math.PI;
			this.mesh.add(frontWindow);

			var backWindow = horzWindow.clone();
			backWindow.position.set(0,1.4,3.01);
			this.mesh.add(backWindow);

			// V. Lights
			var lightGeo = new THREE.PlaneBufferGeometry(1,0.5),
				frontLightMat = new THREE.MeshLambertMaterial({
					color: 0xf1f1f1
				}),
				frontLight = new THREE.Mesh(lightGeo,frontLightMat),
				backLightMat = new THREE.MeshLambertMaterial({
					color: 0xf65555
				}),
				backLight = new THREE.Mesh(lightGeo,backLightMat);

			frontLight.rotation.y = Math.PI;

			var frontLeftLight = frontLight.clone();
			frontLeftLight.position.set(-2,0.25,-5.01);
			this.mesh.add(frontLeftLight);

			var frontRightLight = frontLight.clone();
			frontRightLight.position.set(2,0.25,-5.01);
			this.mesh.add(frontRightLight);

			var backLeftLight = backLight.clone();
			backLeftLight.position.set(-2,0.25,5.01);
			this.mesh.add(backLeftLight);

			var backRightLight = backLight.clone();
			backRightLight.position.set(2,0.25,5.01);
			this.mesh.add(backRightLight);
		}
	}
	class Truck {
		constructor(color,x,z,name) {
			// I. Group
			this.mass = 4;
			this.mesh = new THREE.Object3D();
			this.mesh.name = name;
			this.mesh.position.set(x,2.5,z);
			scene.add(this.mesh);

			// II. Body
			var truckBodyBase = new THREE.Mesh(new THREE.BoxBufferGeometry(5,4,10)),
				cutFront = new THREE.Mesh(new THREE.BoxBufferGeometry(5,1.5,2.5)),
				cutBack = new THREE.Mesh(new THREE.BoxBufferGeometry(5,1.5,4.5)),
				frontTireHoles = new THREE.Mesh(new THREE.CylinderBufferGeometry(1.2,1.2,5,16,16,false)),
				backTireHoles = frontTireHoles.clone(),
				trunk = new THREE.Mesh(new THREE.BoxBufferGeometry(4.4,1.5,4));

			cutFront.position.set(0,1.25,-3.75);
			cutBack.position.set(0,1.25,3);

			frontTireHoles.position.set(0,-2,-3);
			frontTireHoles.rotation.z = 90 * Math.PI/180;

			backTireHoles.position.set(0,-2,3);
			backTireHoles.rotation.z = frontTireHoles.rotation.z;

			trunk.position.set(0,0.1,2.75);

			truckBodyBase.updateMatrix();
			cutFront.updateMatrix();
			cutBack.updateMatrix();
			frontTireHoles.updateMatrix();
			backTireHoles.updateMatrix();
			trunk.updateMatrix();

			var truckBodyBase_BSP = CSG.fromMesh(truckBodyBase),
				cutFront_BSP = CSG.fromMesh(cutFront),
				cutBack_BSP = CSG.fromMesh(cutBack),
				frontTireHoles_BSP = CSG.fromMesh(frontTireHoles),
				backTireHoles_BSP = CSG.fromMesh(backTireHoles),
				trunk_BSP = CSG.fromMesh(trunk),
				truckBody_BSP = truckBodyBase_BSP
					.subtract(cutFront_BSP)
					.subtract(cutBack_BSP)
					.subtract(frontTireHoles_BSP)
					.subtract(backTireHoles_BSP)
					.subtract(trunk_BSP),
				truckBody = CSG.toMesh(truckBody_BSP, truckBodyBase.matrix);

			truckBody.material = new THREE.MeshLambertMaterial({
				color: color
			});
			truckBody.position.set(0,0.5,0);
			truckBody.castShadow = true;
			this.mesh.add(truckBody);

			// III. Wheels
			var wheelGeo = new THREE.CylinderBufferGeometry(1,1,0.5,24,24,false),
				wheelMat = new THREE.MeshLambertMaterial({
					color: 0x171717
				}),
				wheel = new THREE.Mesh(wheelGeo,wheelMat);
			wheel.castShadow = true;
			wheel.rotation.z = -0.5 * Math.PI;

			var wheelPos = [
				{x: -2.25, y: -1.5, z: 3, name: "BL"},
				{x: 2.25, y: -1.5, z: 3, name: "BR"},
				{x: -2.25, y: -1.5, z: -3, name: "FL"},
				{x: 2.25, y: -1.5, z: -3, name: "FR"}
			];
			for (let p of wheelPos) {
				var w = wheel.clone();
				w.name = p.name;
				w.position.set(p.x,p.y,p.z);
				this.mesh.add(w);
			}

			// IV. Windows
			var windowMat = new THREE.MeshLambertMaterial({
					color: 0x171717
				}),

				horzWindowGeo = new THREE.PlaneBufferGeometry(4.4,1.2),
				horzWindowMat = windowMat,
				horzWindow = new THREE.Mesh(horzWindowGeo,horzWindowMat),

				midFrontWindowGeo = new THREE.PlaneBufferGeometry(1.4,1.2),
				midFrontWindowMat = windowMat,
				midFrontWindow = new THREE.Mesh(midFrontWindowGeo,midFrontWindowMat),

				midBackWindowGeo = new THREE.PlaneBufferGeometry(1,1.2),
				midBackWindowMat = windowMat,
				midBackWindow = new THREE.Mesh(midBackWindowGeo,midBackWindowMat);

			horzWindow.receiveShadow = true;
			midFrontWindow.receiveShadow = true;
			midBackWindow.receiveShadow = true;

			var leftMFWindow = midFrontWindow.clone();
			leftMFWindow.position.set(-2.51,1.55,-1.55);
			leftMFWindow.rotation.y = -0.5 * Math.PI;
			this.mesh.add(leftMFWindow);

			var rightMFWindow = midFrontWindow.clone();
			rightMFWindow.position.set(2.51,1.55,-1.55);
			rightMFWindow.rotation.y = 0.5 * Math.PI;
			this.mesh.add(rightMFWindow);

			var leftMBWindow = midBackWindow.clone();
			leftMBWindow.position.set(-2.51,1.55,-0.05);
			leftMBWindow.rotation.y = -0.5 * Math.PI;
			this.mesh.add(leftMBWindow);

			var rightMBWindow = midBackWindow.clone();
			rightMBWindow.position.set(2.51,1.55,-0.05);
			rightMBWindow.rotation.y = 0.5 * Math.PI;
			this.mesh.add(rightMBWindow);

			var frontWindow = horzWindow.clone();
			frontWindow.position.set(0,1.55,-2.51);
			frontWindow.rotation.y = Math.PI;
			this.mesh.add(frontWindow);

			var backWindow = horzWindow.clone();
			backWindow.position.set(0,1.55,0.76);
			this.mesh.add(backWindow);

			/// V. Lights
			var lightGeo = new THREE.PlaneBufferGeometry(0.75,1),
				frontLightMat = new THREE.MeshLambertMaterial({
					color: 0xf1f1f1
				}),
				frontLight = new THREE.Mesh(lightGeo,frontLightMat),
				backLightMat = new THREE.MeshLambertMaterial({
					color: 0xf65555
				}),
				backLight = new THREE.Mesh(lightGeo,backLightMat);

			frontLight.rotation.y = Math.PI;

			var frontLeftLight = frontLight.clone();
			frontLeftLight.position.set(-2.125,0.25,-5.01);
			this.mesh.add(frontLeftLight);

			var frontRightLight = frontLight.clone();
			frontRightLight.position.set(2.125,0.25,-5.01);
			this.mesh.add(frontRightLight);

			var backLeftLight = backLight.clone();
			backLeftLight.position.set(-2.125,0.25,5.01);
			this.mesh.add(backLeftLight);

			var backRightLight = backLight.clone();
			backRightLight.position.set(2.125,0.25,5.01);
			this.mesh.add(backRightLight);
		}
	}
	class TractorTrailer {
		constructor(color,x,z,name) {
			// I. Group
			this.mass = 12;
			this.mesh = new THREE.Object3D();
			this.mesh.name = name;
			this.mesh.position.set(x,4,z);
			scene.add(this.mesh);

			// II. Cab
			var cabPt1Geo = new THREE.BoxBufferGeometry(5,4,5),
				cabPt1Mat = new THREE.MeshLambertMaterial({
					color: color
				}),
				cabPt1 = new THREE.Mesh(cabPt1Geo,cabPt1Mat);
			cabPt1.position.set(0,1,-6.5);
			cabPt1.castShadow = true;
			this.mesh.add(cabPt1);

			var cabPt2Geo = new THREE.BoxBufferGeometry(5,2,0.5),
				cabPt2Mat = cabPt1Mat,
				cabPt2 = new THREE.Mesh(cabPt2Geo,cabPt2Mat);
			cabPt2.position.set(0,-2,-8.75);
			cabPt2.castShadow = true;
			this.mesh.add(cabPt2);

			var cabPt3Geo = new THREE.BoxBufferGeometry(3,2,8.25),
				cabPt3Mat = new THREE.MeshLambertMaterial({
					color: 0x3f3f3f
				}),
				cabPt3 = new THREE.Mesh(cabPt3Geo,cabPt3Mat);
			cabPt3.position.set(0,-2,-4.375);
			cabPt3.castShadow = true;
			this.mesh.add(cabPt3);

			var cabLeftWindowGeo = new THREE.PlaneBufferGeometry(2.5,2),
				cabLeftWindowMat = new THREE.MeshLambertMaterial({
					color: 0x171717
				}),
	        	cabLeftWindow = new THREE.Mesh(cabLeftWindowGeo,cabLeftWindowMat);
			cabLeftWindow.position.set(-2.51,1,-7.75);
			cabLeftWindow.rotation.y = -0.5 * Math.PI;
			cabLeftWindow.receiveShadow = true;
			this.mesh.add(cabLeftWindow);

			var cabRightWindow = cabLeftWindow.clone();
			cabRightWindow.position.x = -cabLeftWindow.position.x;
			cabRightWindow.rotation.y = -cabLeftWindow.rotation.y;
			this.mesh.add(cabRightWindow);

			var cabFrontWindowGeo = new THREE.PlaneBufferGeometry(5,2),
				cabFrontWindowMat = cabLeftWindowMat,
	        	cabFrontWindow = new THREE.Mesh(cabFrontWindowGeo,cabFrontWindowMat);
			cabFrontWindow.position.set(0,1,-9.01);
			cabFrontWindow.rotation.y = Math.PI;
			cabFrontWindow.receiveShadow = true;
			this.mesh.add(cabFrontWindow);

			var lightGeo = new THREE.PlaneBufferGeometry(1,1),
				lightMat = new THREE.MeshLambertMaterial({
					color: 0xf1f1f1
				}),
				light = new THREE.Mesh(lightGeo,lightMat);

			light.rotation.y = Math.PI;

			var leftLight = light.clone();
			leftLight.position.set(-1.5,-1.5,-9.01);
			this.mesh.add(leftLight);

			var rightLight = light.clone();
			rightLight.position.set(1.5,-1.5,-9.01);
			this.mesh.add(rightLight);

			// III. Metal Cylinders
			var cabLeftCylinderGeo = new THREE.CylinderBufferGeometry(0.75,0.75,2.25,16,16,false),
				cabLeftCylinderMat = new THREE.MeshLambertMaterial({
					color: 0x7f7f7f
				}),
				cabLeftCylinder = new THREE.Mesh(cabLeftCylinderGeo,cabLeftCylinderMat);
			cabLeftCylinder.position.set(-2.25,-1.875,-3.875);
			cabLeftCylinder.rotation.x = -0.5 * Math.PI;
			cabLeftCylinder.castShadow = true;
			this.mesh.add(cabLeftCylinder);

			var cabRightCylinder = cabLeftCylinder.clone();
			cabRightCylinder.position.x = -cabLeftCylinder.position.x;
			this.mesh.add(cabRightCylinder);

			// IV. Trailer
			var trailerGeo = new THREE.BoxBufferGeometry(5,5,12),
				trailerMat = new THREE.MeshLambertMaterial({
					color: 0xffffff
				}),
				trailer = new THREE.Mesh(trailerGeo,trailerMat);
			trailer.position.set(0,1.5,3);
			trailer.castShadow = true;
			this.mesh.add(trailer);

			var trailerBottomGeo = new THREE.BoxBufferGeometry(3,2,2),
				trailerBottomMat = cabPt3Mat,
				trailerBottom = new THREE.Mesh(trailerBottomGeo,trailerBottomMat);
			trailerBottom.position.set(0,-2,7);
			trailerBottom.castShadow = true;
			this.mesh.add(trailerBottom);

			// V. Wheels
			var wheelGeo = new THREE.CylinderBufferGeometry(1.5,1.5,1,24,24,false),
				wheelMat = new THREE.MeshLambertMaterial({
					color: 0x242424
				}),
				wheel = new THREE.Mesh(wheelGeo,wheelMat);
			wheel.castShadow = true;
			wheel.rotation.z = -0.5 * Math.PI;

			var wheelPos = [
				{x: -2, y: -2.5, z: 7, name: "BL"},
				{x: 2, y: -2.5, z: 7, name: "BR"},
				{x: -2, y: -2.5, z: -1, name: "ML"},
				{x: 2, y: -2.5, z: -1, name: "MR"},
				{x: -2, y: -2.5, z: -6.75, name: "FL"},
				{x: 2, y: -2.5, z: -6.75, name: "FR"}
			];
			for (let p of wheelPos) {
				var w = wheel.clone();
				w.name = p.name;
				w.position.set(p.x,p.y,p.z);
				this.mesh.add(w);
			}
		}
	}
	class Spark {
		constructor(x,y,z,isHorz = false) {
			this.center = new THREE.Object3D();
			this.center.name = "Spark";
			this.center.position.set(x,y,z);
			scene.add(this.center);

			this.isHorz = isHorz;
			this.particles = [];

			// populate particles
			let particleGeo = new THREE.SphereBufferGeometry(1,16,16),
				particleMat = new THREE.MeshBasicMaterial({
					color: 0xffff00
				}),
				particleMesh = new THREE.Mesh(particleGeo,particleMat);

			for (var m = 0; m < randomInt(6,8); ++m) {
				this.particles.push({
					x: 0,
					y: 0,
					z: 0,
					size: 1,
					speed: 0.2,
					decay: 0.04,
					angle: randomInt(0,359),
					mesh: particleMesh.clone()
				});
				this.center.add(this.particles[m].mesh);
			}
		}
		moveParticles() {
			// shrink particles as they move
			for (let p of this.particles) {
				if (p.size > 0) {
					p.size -= p.decay;

					if (this.isHorz === true) {
						p.x += p.speed * Math.sin(p.angle * Math.PI/180);
						p.mesh.position.x = p.x;
					}
					else {
						p.z += p.speed * Math.sin(p.angle * Math.PI/180);
						p.mesh.position.z = p.z;
					}

					p.y += p.speed * Math.cos(p.angle * Math.PI/180);
					p.mesh.position.y = p.y;

					p.mesh.scale.x = p.size;
					p.mesh.scale.y = p.size;
					p.mesh.scale.z = p.size;
				}
			}
		}
	}

	var init = () => {
			// I. Setting Up Scene
			scene = new THREE.Scene();
			camera = new THREE.PerspectiveCamera(45,window.innerWidth / window.innerHeight,0.1,2000);
			renderer = new THREE.WebGLRenderer({
				logarithmicDepthBuffer: true
			});
			renderer.setClearColor(new THREE.Color(skyColor));
			renderer.setSize(window.innerWidth, window.innerHeight);
			renderer.shadowMap.enabled = true;

			// II. Lighting
			// A. Ambient
			var ambientLight = new THREE.AmbientLight(0xffffff);
			ambientLight.name = "Ambient Light";
			scene.add(ambientLight);

			// B. Hemisphere
			hemiLight = new THREE.HemisphereLight(0x0044ff, 0xffffff, 0.5);
			hemiLight.name = "Hemisphere Light";
			hemiLight.position.set(0,5,0);
			scene.add(hemiLight);
			
			// C. Point
			pointLight = new THREE.PointLight(0xffffff,0.5);
			pointLight.name = "Point Light";
			pointLight.position.set(0,60,pointLightZ);
			pointLight.castShadow = true;
			pointLight.shadow.mapSize = new THREE.Vector2(1024,1024);
			scene.add(pointLight);

			// III. Scenery
			// A. Road
			for (let r = 1; r > -renderDistance; --r)
				roadChunks.push(new RoadChunk(r));

			// B. Grass
			var firstChunkSize = roadChunks[0].chunkSize,
				grassDepth = firstChunkSize * (renderDistance + 1),
				grassGeo = new THREE.PlaneBufferGeometry(400,grassDepth),
				grassMat = new THREE.MeshLambertMaterial({
					color: 0xbbe868
				}),
				grass = new THREE.Mesh(grassGeo,grassMat);

			grass.name = "Grass";
			grass.rotation.x = -Math.PI/2;
			grass.position.set(0,-0.05,-grassDepth/2 + firstChunkSize*1.5);
			grass.receiveShadow = true;
			scene.add(grass);

			// C. Fog
			scene.fog = new THREE.Fog(skyColor, 0.01, grassDepth - firstChunkSize*2);

			// IV. Camera
			camera.position.set(0,cameraYMin,30);
			camera.lookAt(scene.position);
			
			// V. Rendering
			document.body.appendChild(renderer.domElement);
		},
		checkCollision = (a,b) => {
			if (!a.crashed && !b.crashed && (a.name != b.name)) {
				let A_left = a.x - a.width/2,
					A_right = a.x + a.width/2,
					A_front = a.z - a.depth/2,
					A_back = a.z + a.depth/2,
					B_left = b.x - b.width/2,
					B_right = b.x + b.width/2,
					B_front = b.z - b.depth/2,
					B_back = b.z + b.depth/2;

				// right hits left, left hits right
				let touchedX_RL = (A_left <= B_right && A_left >= B_left),
					touchedX_LR = (A_right >= B_left && A_right <= B_right),
				// front hits back, back hits front
					touchedZ_FB = (A_front <= B_back && A_front >= B_front),
					touchedZ_BF = (A_back >= B_front && A_back <= B_back);
				
				if ((touchedX_RL || touchedX_LR) && (touchedZ_FB || touchedZ_BF)) {
					var newMomentum = (a.model.mass * a.speed + b.model.mass * b.speed)/(a.model.mass + b.model.mass);

					a.speed = newMomentum;
					b.speed = newMomentum;
					
					let sx = 0,
						sz = 0;

					// x-center the spark between crashing ends
					if (A_left <= B_right)
						sx = (A_left + B_right)/2;
					else if (A_right >= B_left)
						sx = (A_right + B_left)/2;

					// then z-center it
					if (A_front <= B_back)
						sz = (A_front + B_back)/2;
					else if (A_back >= B_front)
						sz = (A_back + B_front)/2;

					// trigger spark for player vehicle
					if (a.name == "Vehicle 0") {
						a.crashed = true;
						game.over = true;
						game.spark = new Spark(sx,a.height/2,sz,A_front - B_back < 1);
					}
				}
			}
		},
		toggleDifBtnStates = () => {
			for (let b of difButtons)
				b.disabled = !b.disabled;
		},
		toggleDifMenu = () => {
			difSelectActive = !difSelectActive;

			let activeClass = "menu-active",
				inactiveClass = "menu-inactive";

			if (difSelectActive) {
				difSelect.classList.remove(inactiveClass);
				void difSelect.offsetWidth;
				difSelect.classList.add(activeClass);
				setTimeout(toggleDifBtnStates,1500);

			} else {
				difSelect.classList.remove(activeClass);
				void difSelect.offsetWidth;
				difSelect.classList.add(inactiveClass);
				toggleDifBtnStates();
			}
		},
		toggleScoreCounter = () => {
			scoreCounterActive = !scoreCounterActive;

			let activeClass = "score-active";

			if (scoreCounterActive)
				header.classList.add(activeClass);
			else
				header.classList.remove(activeClass);
		},
		toggleReplayBtn = () => {
			replayBtnActive = !replayBtnActive;
			replayButton.disabled = !replayBtnActive;

			let activeClass = "replay-active";

			if (replayBtnActive)
				replayButton.classList.add(activeClass);
			else
				replayButton.classList.remove(activeClass);
		},
		showTutorial = () => {
			if (game.tutorial)
				tutorialBox.classList.add("tutorial-active");
		},
		hideTutorial = () => {
			if (game.tutorial) {
				game.tutorial = false;
				tutorialBox.classList.remove("tutorial-active");
			}
		},
		startGame = difficulty => {
			if (game != null && game.over) {
				// remove spark
				if (game.spark != null) {
					let sparkName = scene.getObjectByName(game.spark.name);
					scene.remove(sparkName);
				}
				// remove all vehicles
				for (let v of game.vehicles) {
					let vehicleName = scene.getObjectByName(v.name);
					scene.remove(vehicleName);
				}
			}

			// first time or starting anew
			if (game == null || game.over) {
				game = new Game({
					difficulty: difficulty,
					tutorial: game == null
				});
				header.innerHTML = game.score;
				toggleScoreCounter();
				showTutorial();
			}
		},
		update = () => {
			// intro sequence
			if (cameraY > cameraYMin) {
				cameraY -= 0.5;
				if (cameraY == cameraYMin)
					toggleDifMenu();
			}

			// normal game function
			if (game != null && cameraY == cameraYMin) {
				let firstChunkSize = roadChunks[0].chunkSize,
					vehicleCtrld = game.vehicles[game.vehicleIDCtrld];

				// push all vehicles forward one chunk when player reaches that distance
				if (vehicleCtrld.z <= -firstChunkSize) {
					let vehiclesBehind = [];
					game.vehicles.forEach((e,i) => {
						e.z += firstChunkSize;

						// mark for removal if no longer seen
						if (e.z - e.depth/2 > vehicleCtrld.z + firstChunkSize/2) {
							vehiclesBehind.push({
								index: i,
								name: e.name
							});
						}
					});
					// remove vehicles way behind, score
					vehiclesBehind.sort((a,b) => b.index - a.index);
					for (let v of vehiclesBehind) {
						let objectName = scene.getObjectByName(v.name);
						scene.remove(objectName);
						game.vehicles.splice(v.index,1);

						// score points for passing without using shoulder
						if (Math.abs(vehicleCtrld.x) < game.noScoreXZone) {
							++game.score;
							header.innerHTML = game.score;
						}
					}

					// and then spawn 0–3 new ones
					if (game.vehicles.length < game.vehicleLimit && !game.tutorial) {
						let spawnTries = 3;
						while (spawnTries--) {
							if (Math.random() < 0.05 + game.difficulty * 0.025) {
								game.vehicles.push(new Vehicle({
									x: (-1 + spawnTries) * 10,
									z: -renderDistance * firstChunkSize - spawnTries * 15,
									name: "Vehicle " + game.vehicleSpawns
								}));
								++game.vehicleSpawns;
							}
						}
					}
				}

				// move vehicles
				let vehiclesAhead = [];
				game.vehicles.forEach((e,i) => {
					e.move();

					for (let v of game.vehicles)
						checkCollision(e,v);

					if (!game.tutorial) {
						if (!e.crashed)
							e.accelerate();
						else {
							e.decelerate();

							// spinout if steering
							if (e.steerAngle > 0)
								e.steerAngle += e.speed * e.steerSpeed;
							else if (e.steerAngle < 0)
								e.steerAngle -= e.speed * e.steerSpeed;
						}
					}
					
					// mark for removal if no longer seen
					if (e.z < (-renderDistance - 1.5) * firstChunkSize) {
						vehiclesAhead.push({
							index: i,
							name: e.name
						});
					}
				});
				// remove vehicles way ahead
				vehiclesAhead.sort((a,b) => b.index - a.index);
				for (let v of vehiclesAhead) {
					let objectName = scene.getObjectByName(v.name);
					scene.remove(objectName);
					game.vehicles.splice(v.index,1);
				}

				// spark from crash
				if (game.spark != null) {
					game.spark.moveParticles();
					game.spark.center.position.z = vehicleCtrld.z - (game.spark.isHorz ? vehicleCtrld.depth/2 : 0);
				}

				// show difficulty menu on game over
				if (vehicleCtrld.speed <= 0 && game.over && !game.preparingNew && !replayBtnActive)
					toggleReplayBtn();

				// center spotlight and camera on player vehicle
				pointLight.position.z = vehicleCtrld.z + pointLightZ;
				camera.position.set(0,cameraY,vehicleCtrld.z + 30);

			} else {
				pointLight.position.z = pointLightZ;
				camera.position.set(0,cameraY,30);
			}

			renderer.render(scene,camera);
			requestAnimationFrame(update);
		},
		adjustWindow = () => {
			camera.aspect = window.innerWidth / window.innerHeight;
			camera.updateProjectionMatrix();
			renderer.setSize(window.innerWidth,window.innerHeight)
		},
		steerVehicle = e => {
			if (game != null && !game.over && game.vehicles.length) {
				let playerVehicle = game.vehicles[game.vehicleIDCtrld];

				// left arrow, A, or drag left
				if ((e.keyCode && (e.keyCode == 37 || e.keyCode == 65)) || 
					(touch.hold && e.pageX < touch.x)) {
					playerVehicle.steer("left");
					hideTutorial();

				// right arrow, D, or drag right
				} else if ((e.keyCode && (e.keyCode == 39 || e.keyCode == 68)) || 
					(touch.hold && e.pageX > touch.x)) {
					playerVehicle.steer("right");
					hideTutorial();
				}
			}
		},
		straightenVehicle = () => {
			if (game != null && !game.over && game.vehicles.length) {
				game.vehicles[game.vehicleIDCtrld].straighten();
			}
			touch.hold = false;
		},
		getTouchHold = e => {
			touch.hold = true;
			touch.x = e.pageX;
		};

	init();
	update();
	
	window.addEventListener("resize",adjustWindow);

	// steering
	var downEvent = "ontouchstart" in document.documentElement ? "touchstart" : "mousedown",
		moveEvent = "ontouchmove" in document.documentElement ? "touchmove" : "mousemove",
		upEvent = "ontouchend" in document.documentElement ? "touchend" : "mouseup";

	document.addEventListener("keydown",steerVehicle);
	document.addEventListener("keyup",straightenVehicle);
	document.addEventListener(downEvent,getTouchHold);
	document.addEventListener(moveEvent,steerVehicle);
	document.addEventListener(upEvent,straightenVehicle);

	// difficulty buttons
	for (let b of difButtons) {
		b.addEventListener("click",function(){
			toggleDifMenu();

			let t = this;
			setTimeout(() => {
				startGame(t.getAttribute("data-difficulty"));
			},1600);
		});
	}

	// replay button
	replayButton.addEventListener("click",function(){
		game.preparingNew = true;
		toggleScoreCounter();
		toggleReplayBtn();
		setTimeout(toggleDifMenu,250);
	});
}
              
            
!
999px

Console