self driving car

sensor.js

@@ -0,0 +1,95 @@
+class Sensor {
+	constructor(car) {
+		this.car = car;
+		this.rayCount = 5;
+		this.rayLength = 150;
+		this.raySpread = Math.PI / 2;
+
+		this.rays = [];
+		this.readings = [];
+	}
+	update(roadBorders, traffic) {
+		this.#castRays();
+		this.readings = [];
+		for (let i = 0; i < this.rays.length; i++) {
+			this.readings.push(
+				this.#getReading(
+					this.rays[i],
+					roadBorders,
+					traffic
+				)
+			);
+		}
+	}
+	#getReading(ray, roadBorders, traffic) {
+		let touches = [];
+		for (let i = 0; i < roadBorders.length; i++) {
+			const touch = getIntersection(
+				ray[0],
+				ray[1],
+				roadBorders[i][0],
+				roadBorders[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 value = getIntersection(
+					ray[0],
+					ray[1],
+					poly[j],
+					poly[(j + 1) % poly.length]
+				);
+				if (value) touches.push(value);
+			}
+		}
+		if (touches.length == 0) return null;
+		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,
+					this.rayCount == 1
+						? 0.5
+						: 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();
+		}
+	}
+}