main.js

const carCanvas = document.getElementById('carCanvas');
carCanvas.width = 200;
const networkCanvas = document.getElementById('networkCanvas');
networkCanvas.width = 300;

const carCtx = carCanvas.getContext('2d');
const networkCtx = networkCanvas.getContext('2d');

const road = new Road(carCanvas.width / 2, carCanvas.width * 0.9);
const N = 500;
const cars = generateCars(N);
let bestCar = cars[0];
if (localStorage.getItem("bestBrain")) {
    for (let i = 0; i < cars.length; ++i) {
        // We have to serialize it as JSON because localStorage only works with strings
        cars[i].brain = JSON.parse(localStorage.getItem("bestBrain"));
        if (i != 0) {
            NeuralNetwork.mutate(cars[i].brain, 0.2);
        }
    }
}

const traffic = [
    new Car(road.getLaneCenter(1), -100, 30, 50, "DUMMY", 2),
    new Car(road.getLaneCenter(0), -300, 30, 50, "DUMMY", 2),
    new Car(road.getLaneCenter(2), -300, 30, 50, "DUMMY", 2),
    new Car(road.getLaneCenter(0), -500, 30, 50, "DUMMY", 2),
    new Car(road.getLaneCenter(1), -500, 30, 50, "DUMMY", 2),
    new Car(road.getLaneCenter(1), -700, 30, 50, "DUMMY", 2),
    new Car(road.getLaneCenter(2), -700, 30, 50, "DUMMY", 2)
];

animate();

function save() {
    localStorage.setItem("bestBrain", JSON.stringify(bestCar.brain));
}

function discard() {
    localStorage.removeItem("bestBrain");
}

function generateCars(N) {
    const cars = [];

    for (let i = 1; i <= N; ++i) {
        cars.push(new Car(road.getLaneCenter(1), 100, 30, 50, "AI"));
    }

    return cars;
}

// `time` argument will come from `requestAnimationFrame` below
function animate(time) {
    //
    // Updates
    //
    for (let i = 0; i < traffic.length; ++i) {
        traffic[i].update(road.borders, []);
    }

    for (let i = 0; i < cars.length; ++i) {
        cars[i].update(road.borders, traffic);
    }

    // Best car is the one with minimum y value out of all cars
    bestCar = cars.find(c => c.y == Math.min(...cars.map(c => c.y)));

    //
    // Draws
    //
    carCanvas.height = window.innerHeight;
    networkCanvas.height = window.innerHeight;

    carCtx.save();
    carCtx.translate(0, -bestCar.y + carCanvas.height * 0.7);
    
    road.draw(carCtx);
    for (let i = 0; i < traffic.length; ++i) {
        traffic[i].draw(carCtx, "red");
    }

    carCtx.globalAlpha = 0.2;
    for (let i = 1; i < cars.length; ++i) {
        cars[i].draw(carCtx, "blue");
    }
    carCtx.globalAlpha = 1;
    bestCar.draw(carCtx, "blue", true);

    carCtx.restore();

    networkCtx.lineDashOffset = - time / 100;
    Visualizer.drawNetwork(networkCtx, bestCar.brain);

    // Below function accepts a function as an argument and repeatedly calls it.
    requestAnimationFrame(animate);
}