sensor.js

class Sensor{
    constructor(car){
        this.car = car;
        this.rayCount = 5;
        this.rayLength = 150;
        this.raySpread = Math.PI/2;

        this.rays = [];
        this.readings = [];
    }

    update(roadBoarders, traffic){
        this.#castRays();
        this.readings = [];
        for(let i = 0; i < this.rays.length; i++){
            this.readings.push(
                this.#getReading(this.rays[i], roadBoarders, traffic)
            );
        }
    }

    #getReading(ray, roadBoarders, traffic){
        let touches = [];

        for(let i = 0; i < roadBoarders.length; i++){
            const touch = getIntersection(ray[0], ray[1], roadBoarders[i][0], roadBoarders[i][1]);
            if (touch){
                touches.push(touch);
            }
        }

        for (let i = 0; i < traffic.length; i++){
            const poly = traffic[i].polygon;
            for (let j = 0; j < poly.length; j++){
                const touch = getIntersection(ray[0], ray[1], poly[j], poly[(j+1)%poly.length])
                if (touch){
                    touches.push(touch);
                }
            }
        }

        if (touches.length == 0){
            return null;
        }else{
            const offsets = touches.map(e => e.offset);
            const minOffset = Math.min(...offsets);
            return touches.find(e => e.offset == minOffset);
        }
    }

    #castRays(){
        this.rays = [];
        for (let i = 0; i <this.rayCount; i++){
            const rayAngle = lerp(
                this.raySpread/2,
                -this.raySpread/2,
                i/(this.rayCount - 1)
            ) + this.car.angle;

            const start = {x:this.car.x, y:this.car.y};
            const end = {x:this.car.x - Math.sin(rayAngle) * this.rayLength, y:this.car.y - Math.cos(rayAngle) * this.rayLength};
            this.rays.push([start,end]);
        }
    }

    draw(ctx){
        for(let i = 0; i < this.rayCount; i++){
            let end =  this.rays[i][1];
            if (this.readings[i]){
                end = this.readings[i]
            }


            ctx.beginPath();
            ctx.lineWidth = 2;
            ctx.strokeStyle = "yellow";
            ctx.moveTo(this.rays[i][0].x, this.rays[i][0].y);
            ctx.lineTo(end.x, end.y);
            ctx.stroke();

            ctx.beginPath();
            ctx.lineWidth = 2;
            ctx.strokeStyle = "black";
            ctx.moveTo(this.rays[i][1].x, this.rays[i][1].y);
            ctx.lineTo(end.x, end.y);
            ctx.stroke();
        }
    }
}