self-driving-car/car.js

class Car {
	constructor(
		x,
		y,
		controlType,
		color = "blue",
		maxSpeed = 4,
		width = 30,
		height = 50
	) {
		this.x = x;
		this.y = y;
		this.width = width;
		this.height = height;

		this.speed = 0;
		this.acceleration = 0.2;
		this.maxSpeed = maxSpeed;
		this.friction = 0.05;
		this.angle = 0;
		this.useBrain = controlType == "AI";
		if (controlType != "DUMMY") {
			this.sensor = new Sensor(this);
			this.brain = new NeuralNetwork([
				this.sensor.rayCount,
				6,
				4,
			]);
		}
		this.controls = new Controls(controlType);
		this.img = new Image();
		this.img.src = "car.png";
		this.mask = document.createElement("canvas");
		this.mask.width = width;
		this.mask.height = height;

		const maskCtx = this.mask.getContext("2d");
		this.img.onload = () => {
			maskCtx.fillStyle = color;
			maskCtx.rect(0, 0, this.width, this.height);
			maskCtx.fill();

			maskCtx.globalCompositeOperation = "destination-atop";
			maskCtx.drawImage(
				this.img,
				0,
				0,
				this.width,
				this.height
			);
		};
	}
	update(roadBorders, traffic) {
		if (!this.damaged) {
			this.#move();
			this.polygon = this.#createPolygon();
			this.damaged = this.#assessDamage(roadBorders, traffic);
		}
		if (this.sensor) {
			this.sensor.update(roadBorders, traffic);
			const offsets = this.sensor.readings.map((s) =>
				s == null ? 0 : 1 - s.offset
			);
			const outputs = NeuralNetwork.feedForward(
				offsets,
				this.brain
			);
			if (this.useBrain) {
				this.controls.forward = outputs[0];
				this.controls.left = outputs[1];
				this.controls.right = outputs[2];
				this.controls.reverse = outputs[3];
			}
		}
	}
	#assessDamage(roadBorders, traffic) {
		for (let i = 0; i < roadBorders.length; i++) {
			if (polyIntersect(this.polygon, roadBorders[i]))
				return true;
		}
		for (let i = 0; i < traffic.length; i++) {
			if (polyIntersect(this.polygon, traffic[i].polygon)) {
				return true;
			}
		}
		return false;
	}
	#createPolygon() {
		const points = [];
		const rad = Math.hypot(this.width, this.height) / 2;
		const alpha = Math.atan2(this.width, this.height);
		points.push({
			x: this.x - Math.sin(this.angle - alpha) * rad,
			y: this.y - Math.cos(this.angle - alpha) * rad,
		});
		points.push({
			x: this.x - Math.sin(this.angle + alpha) * rad,
			y: this.y - Math.cos(this.angle + alpha) * rad,
		});
		points.push({
			x:
				this.x -
				Math.sin(Math.PI + this.angle - alpha) * rad,
			y:
				this.y -
				Math.cos(Math.PI + this.angle - alpha) * rad,
		});
		points.push({
			x:
				this.x -
				Math.sin(Math.PI + this.angle + alpha) * rad,
			y:
				this.y -
				Math.cos(Math.PI + this.angle + alpha) * rad,
		});
		return points;
	}
	#move() {
		if (this.controls.forward) this.speed += this.acceleration;
		else if (this.controls.reverse) this.speed -= this.acceleration;
		if (this.speed > this.maxSpeed) this.speed = this.maxSpeed;
		else if (this.speed < -this.maxSpeed / 2)
			this.speed = -this.maxSpeed / 2;
		if (this.speed > 0) this.speed -= this.friction;
		if (this.speed < 0) this.speed += this.friction;
		if (Math.abs(this.speed) < this.friction) this.speed = 0;
		if (this.speed != 0) {
			const flip = this.speed > 0 ? 1 : -1;
			if (this.controls.left) this.angle += 0.03 * flip;
			if (this.controls.right) this.angle -= 0.03 * flip;
		}
		this.x -= Math.sin(this.angle) * this.speed;
		this.y -= Math.cos(this.angle) * this.speed;
	}
	draw(ctx, color, drawSensor = false) {
		if (this.sensor && drawSensor) this.sensor.draw(ctx);
		ctx.save();
		ctx.translate(this.x, this.y);
		ctx.rotate(-this.angle);
		if (!this.damaged) {
			ctx.drawImage(
				this.mask,
				-this.width / 2,
				-this.height / 2,
				this.width,
				this.height
			);
		}
		ctx.globalCompositeOperation = "multiply";
		ctx.drawImage(
			this.img,
			-this.width / 2,
			-this.height / 2,
			this.width,
			this.height
		);
		ctx.restore();
	}
}

function polyIntersect(poly1, poly2) {
	for (let i = 0; i < poly1.length; i++) {
		for (let j = 0; j < poly2.length; j++) {
			const touch = getIntersection(
				poly1[i],
				poly1[(i + 1) % poly1.length],
				poly2[j],
				poly2[(j + 1) % poly2.length]
			);
			if (touch) return true;
		}
	}
	return false;
}