Car.js

/**
 * @author alteredq / http://alteredqualia.com/
 * @author Tapani Jamsa
 */

THREE.Car = function() {
	var scope = this;

	this.lerp = function(a, b, t) {
		return a + (b - a) * t;
	};

	// car geometry manual parameters

	this.modelScale = 100;

	this.backWheelOffset = 2;

	this.autoWheelGeometry = true;

	// car geometry parameters automatically set from wheel mesh
	// 	- assumes wheel mesh is front left wheel in proper global
	//    position with respect to body mesh
	//	- other wheels are mirrored against car root
	//	- if necessary back wheels can be offset manually

	this.wheelOffsetX = 0;
	this.wheelOffsetY = 0;
	this.wheelOffsetZ = 0;

	this.wheelDiameter = 1;

	// car "feel" parameters

	// DEFAULT VALUES
	this.MAX_SPEED = 2200; // 2200
	this.MAX_REVERSE_SPEED = -1500;

	this.MAX_WHEEL_ROTATION = 0.6;

	this.FRONT_ACCELERATION = 1250;
	this.BACK_ACCELERATION = 1500;

	this.WHEEL_ANGULAR_ACCELERATION = 1.5;

	this.FRONT_DECCELERATION = 750;
	this.WHEEL_ANGULAR_DECCELERATION = 1.0;

	this.STEERING_RADIUS_RATIO = 0.0023;

	this.MAX_TILT_SIDES = 0.05;
	this.MAX_TILT_FRONTBACK = 0.015;

	// internal control variables

	this.speed = 0;
	this.acceleration = 0;

	this.wheelOrientation = 0;
	this.carOrientation = 0;

	// car rigging

	this.root = new THREE.Object3D();

	this.frontLeftWheelRoot = new THREE.Object3D();
	this.frontRightWheelRoot = new THREE.Object3D();

	this.bodyMesh = null;

	// this.frontLeftWheelMesh = null;
	// this.frontRightWheelMesh = null;

	// this.backLeftWheelMesh = null;
	// this.backRightWheelMesh = null;

	this.bodyGeometry = null;
	this.wheelGeometry = null;

	// internal helper variables

	this.loaded = false;

	this.meshes = [];

	this.collisionCounter = 0;

	// API

	this.enableShadows = function(enable) {

		for (var i = 0; i < this.meshes.length; i++) {

			this.meshes[i].castShadow = enable;
			this.meshes[i].receiveShadow = enable;

		}

	};

	this.setVisible = function(enable) {

		for (var i = 0; i < this.meshes.length; i++) {

			this.meshes[i].visible = enable;
			this.meshes[i].visible = enable;

		}

	};

	this.loadPartsJSON = function(bodyURL, wheelURL) {

		var loader = new THREE.JSONLoader();

		loader.load(bodyURL, createBody);
		// loader.load(wheelURL, createWheels);

	};

	this.loadPartsBinary = function(bodyURL, wheelURL) {

		var loader = new THREE.BinaryLoader();

		loader.load({
			model: bodyURL,
			callback: function(geometry) {
				createBody(geometry)
			}
		});
		loader.load({
			model: wheelURL,
			callback: function(geometry) {
				createWheels(geometry)
			}
		});

	};

	this.updateCarModel = function(delta, controls) {

		// speed and wheels based on controls

		if (controls.moveForward) {

			this.speed = clamp(this.speed + delta * this.FRONT_ACCELERATION, this.MAX_REVERSE_SPEED, this.MAX_SPEED);
			this.acceleration = clamp(this.acceleration + delta, -1, 1);

		}

		if (controls.moveBackward) {


			this.speed = clamp(this.speed - delta * this.BACK_ACCELERATION, this.MAX_REVERSE_SPEED, this.MAX_SPEED);
			this.acceleration = clamp(this.acceleration - delta, -1, 1);

		}

		if (controls.moveLeft) {

			this.wheelOrientation = clamp(this.wheelOrientation + delta * this.WHEEL_ANGULAR_ACCELERATION, -this.MAX_WHEEL_ROTATION, this.MAX_WHEEL_ROTATION);

		}

		if (controls.moveRight) {

			this.wheelOrientation = clamp(this.wheelOrientation - delta * this.WHEEL_ANGULAR_ACCELERATION, -this.MAX_WHEEL_ROTATION, this.MAX_WHEEL_ROTATION);

		}

		// speed decay

		if (!(controls.moveForward || controls.moveBackward)) {

			if (this.speed > 0) {

				var k = exponentialEaseOut(this.speed / this.MAX_SPEED);

				this.speed = clamp(this.speed - k * delta * this.FRONT_DECCELERATION, 0, this.MAX_SPEED);
				this.acceleration = clamp(this.acceleration - k * delta, 0, 1);

			} else {

				var k = exponentialEaseOut(this.speed / this.MAX_REVERSE_SPEED);

				this.speed = clamp(this.speed + k * delta * this.BACK_ACCELERATION, this.MAX_REVERSE_SPEED, 0);
				this.acceleration = clamp(this.acceleration + k * delta, -1, 0);

			}


		}

		// steering decay

		if (!(controls.moveLeft || controls.moveRight)) {

			if (this.wheelOrientation > 0) {

				this.wheelOrientation = clamp(this.wheelOrientation - delta * this.WHEEL_ANGULAR_DECCELERATION, 0, this.MAX_WHEEL_ROTATION);

			} else {

				this.wheelOrientation = clamp(this.wheelOrientation + delta * this.WHEEL_ANGULAR_DECCELERATION, -this.MAX_WHEEL_ROTATION, 0);

			}

		}

		var forwardDelta;

		// COLLISION
		var foundCollision = true;

		// Building colliders

		// left back
		var deltaX = Math.floor(Math.sin(this.root.rotation.y - 10) * 1000); // Using a little trigonometry calculate a point in space 1000 units in front of our character
		var deltaZ = Math.floor(Math.cos(this.root.rotation.y - 10) * 1000);
		var focusX = this.root.position.x + deltaX; // Calculate where this collision focus point is in relation to our character position
		var focusZ = this.root.position.z + deltaZ;
		if (isColliding(this.root.position, focusX, focusZ) == false) {
			// right back
			var deltaX = Math.floor(Math.sin(this.root.rotation.y + 10) * 1000);
			var deltaZ = Math.floor(Math.cos(this.root.rotation.y + 10) * 1000);
			var focusX = this.root.position.x + deltaX;
			var focusZ = this.root.position.z + deltaZ;

			if (isColliding(this.root.position, focusX, focusZ) == false) {
				// right front
				var deltaX = Math.floor(Math.sin(this.root.rotation.y - 10) * 1000);
				var deltaZ = Math.floor(Math.cos(this.root.rotation.y - 10) * 1000);
				var focusX = this.root.position.x - deltaX;
				var focusZ = this.root.position.z - deltaZ;

				if (isColliding(this.root.position, focusX, focusZ) == false) {
					// left front
					var deltaX = Math.floor(Math.sin(this.root.rotation.y + 10) * 1000);
					var deltaZ = Math.floor(Math.cos(this.root.rotation.y + 10) * 1000);
					var focusX = this.root.position.x - deltaX;
					var focusZ = this.root.position.z - deltaZ;

					if (isColliding(this.root.position, focusX, focusZ) == false) {
						foundCollision = false;
					}
				}
			}
		}

		if (foundCollision) {
			forwardDelta = this.speed * -3;
			this.speed *= -0.25;
			// this.acceleration = 0;
		}
		// car update
		else {
			forwardDelta = this.speed;
		}

		this.carOrientation += (forwardDelta * this.STEERING_RADIUS_RATIO) * this.wheelOrientation;

		// Ground collider
		var raycaster = new THREE.Raycaster(new THREE.Vector3(this.root.position.x, this.root.position.y + 50, this.root.position.z), new THREE.Vector3(0, -1, 0), 0, 500);

		for (var x = 0; x < gridManager.visibleBlocks.length; x++) {
			for (var z = 0; z < gridManager.visibleBlocks.length; z++) {
				var intersects = raycaster.intersectObject(gridManager.visibleBlocks[x][z].colliders[1]);

				if (intersects.length > 0) {
					// console.log("plane collision: " + intersects.length);
					// console.log(intersects[0]);
					// console.log(intersects[0].point);
					// this begin = this.root.position.y;
					// var target = intersects[0].point.y + 1;

					this.root.position.y = this.lerp(this.root.position.y, intersects[0].point.y + 0.8, delta);

					// this.root.position.y = intersects[0].point.y + 1;
					break;
				}
			}
		}

		// displacement


		this.root.position.x += Math.sin(this.carOrientation) * forwardDelta;
		this.root.position.z += Math.cos(this.carOrientation) * forwardDelta;

		// steering

		this.root.rotation.y = this.carOrientation;

		// tilt

		if (this.loaded) {

			this.bodyMesh.rotation.z = this.MAX_TILT_SIDES * this.wheelOrientation * (this.speed / this.MAX_SPEED);
			this.bodyMesh.rotation.x = -this.MAX_TILT_FRONTBACK * this.acceleration;

		}

		// // wheels rolling

		// var angularSpeedRatio = 1 / (this.modelScale * (this.wheelDiameter / 2));

		// var wheelDelta = forwardDelta * angularSpeedRatio;

		// if (this.loaded) {

		// 	this.frontLeftWheelMesh.rotation.x += wheelDelta;
		// 	this.frontRightWheelMesh.rotation.x += wheelDelta;
		// 	this.backLeftWheelMesh.rotation.x += wheelDelta;
		// 	this.backRightWheelMesh.rotation.x += wheelDelta;

		// }

		// // front wheels steering

		// this.frontLeftWheelRoot.rotation.y = this.wheelOrientation;
		// this.frontRightWheelRoot.rotation.y = this.wheelOrientation;

	}

	function isColliding(position, focusX, focusZ) {
		var raycaster = new THREE.Raycaster(position, new THREE.Vector3(focusX, position.y, focusZ), 0, 4);
		for (var x = 0; x < gridManager.visibleBlocks.length; x++) {
			for (var z = 0; z < gridManager.visibleBlocks.length; z++) {
				var intersects = raycaster.intersectObject(gridManager.visibleBlocks[x][z].colliders[0]);
				if (intersects.length > 0) {
					return true;
				}
			}
		}
		return false;
	}

	// internal helper methods

	function createBody(geometry, materials) {

		console.log("create body");

		scope.bodyGeometry = geometry;

		createCar(materials);

	}

	function createWheels(geometry) {

		scope.wheelGeometry = geometry;

		createCar();

	}

	function createCar(materials) {

		if (scope.bodyGeometry /* && scope.wheelGeometry*/ ) {

			// compute wheel geometry parameters

			// if (scope.autoWheelGeometry) {

			// 	scope.wheelGeometry.computeBoundingBox();

			// 	var bb = scope.wheelGeometry.boundingBox;

			// 	var dx = 0.5 * (bb.x[1] + bb.x[0]);
			// 	var dy = 0.5 * (bb.y[1] + bb.y[0]);
			// 	var dz = 0.5 * (bb.z[1] + bb.z[0]);

			// 	scope.wheelOffsetX = dx;
			// 	scope.wheelOffsetY = dy;
			// 	scope.wheelOffsetZ = dz;

			// 	scope.wheelDiameter = bb.y[1] - bb.y[0];

			// 	THREE.GeometryUtils.center(scope.wheelGeometry);

			// }

			// rig the car

			var delta,
				s = scope.modelScale,
				faceMaterial = new THREE.MeshFaceMaterial(materials);

			// body

			scope.bodyMesh = new THREE.Mesh(scope.bodyGeometry, faceMaterial);
			scope.bodyMesh.scale.set(s, s, s);

			scope.root.add(scope.bodyMesh);

			// // front left wheel

			// delta = new THREE.Vector3(s * scope.wheelOffsetX, s * scope.wheelOffsetY, s * scope.wheelOffsetZ);

			// scope.frontLeftWheelRoot.position.add(delta);

			// scope.frontLeftWheelMesh = new THREE.Mesh(scope.wheelGeometry, faceMaterial);
			// scope.frontLeftWheelMesh.scale.set(s, s, s);

			// scope.frontLeftWheelRoot.add(scope.frontLeftWheelMesh);
			// scope.root.add(scope.frontLeftWheelRoot);

			// // front right wheel

			// delta = new THREE.Vector3(-s * scope.wheelOffsetX, s * scope.wheelOffsetY, s * scope.wheelOffsetZ);

			// scope.frontRightWheelRoot.position.add(delta);

			// scope.frontRightWheelMesh = new THREE.Mesh(scope.wheelGeometry, faceMaterial);

			// scope.frontRightWheelMesh.scale.set(s, s, s);
			// scope.frontRightWheelMesh.rotation.z = Math.PI;

			// scope.frontRightWheelRoot.add(scope.frontRightWheelMesh);
			// scope.root.add(scope.frontRightWheelRoot);

			// // back left wheel

			// delta = new THREE.Vector3(s * scope.wheelOffsetX, s * scope.wheelOffsetY, -s * scope.wheelOffsetZ - scope.backWheelOffset);

			// scope.backLeftWheelMesh = new THREE.Mesh(scope.wheelGeometry, faceMaterial);

			// scope.backLeftWheelMesh.position.add(delta);
			// scope.backLeftWheelMesh.scale.set(s, s, s);

			// scope.root.add(scope.backLeftWheelMesh);

			// // back right wheel

			// delta = new THREE.Vector3(-s * scope.wheelOffsetX, s * scope.wheelOffsetY, -s * scope.wheelOffsetZ - scope.backWheelOffset)

			// scope.backRightWheelMesh = new THREE.Mesh(scope.wheelGeometry, faceMaterial);

			// scope.backRightWheelMesh.position.add(delta);
			// scope.backRightWheelMesh.scale.set(s, s, s);
			// scope.backRightWheelMesh.rotation.z = Math.PI;

			// scope.root.add(scope.backRightWheelMesh);

			// cache meshes

			scope.meshes = [scope.bodyMesh /*, scope.frontLeftWheelMesh, scope.frontRightWheelMesh, scope.backLeftWheelMesh, scope.backRightWheelMesh*/ ];

			// callback

			scope.loaded = true;

			if (scope.callback) {

				scope.callback(scope);

			}

		}

	}

	function clamp(x, a, b) {
		return x < a ? a : (x > b ? b : x);
	}

	function quadraticEaseOut(k) {
		return -k * (k - 2);
	}

	function cubicEaseOut(k) {
		return --k * k * k + 1;
	}

	function circularEaseOut(k) {
		return Math.sqrt(1 - --k * k);
	}

	function sinusoidalEaseOut(k) {
		return Math.sin(k * Math.PI / 2);
	}

	function exponentialEaseOut(k) {
		return k == 1 ? 1 : -Math.pow(2, -10 * k) + 1;
	}

};