pong-ml/js/Ball.js

class Ball {
	position = {x:15, y: 20};
	radius = 5;
	game = null;
	velocity = {x:3, y:2.3};
	isAlive = true;
	constructor() {

	}

	init(game) {
		this.game = game;
		this.position.x = Math.floor(this.game.getWidth() * Math.random());
		this.position.y = Math.floor(this.game.getHeight() * Math.random());
		this.velocity.x = Math.floor(6 * Math.random() - 3) || 1;
		this.velocity.y = Math.floor(6 * Math.random() - 3) || 1;
		this.isAlive = true;
	}

	update(delta) {
		this.position.x += delta * this.velocity.x;
		this.position.y += delta * this.velocity.y;

		let collisionBox = {
			left: this.position.x - this.radius,
			top: this.position.y - this.radius,
			right: this.position.x + this.radius,
			bottom: this.position.y + this.radius
		};
		this.handleBorderCollision(collisionBox);
		this.handlePaddleCollision(collisionBox);
	}

	handleBorderCollision(collisionBox) {
		switch(this.game.collideSide(collisionBox)) {
			case "top":
				this.velocity.y *= -1
				this.position.y = this.radius;
				break;
			case "left":
				this.game.getPaddle("right").addPoint();
				this.setDead();
				break;
			case "bottom":
				this.velocity.y *= -1
				this.position.y = this.game.getHeight() - this.radius;
				break;
			case "right":
				this.game.getPaddle("left").addPoint();
				this.setDead();
				break;
			default:
				break;
		}
	}

	handlePaddleCollision(collisionBox) {
		let leftPaddle = this.game.getPaddle("left");
		switch(leftPaddle.collideSide(collisionBox)) {
			case "left":
				this.velocity.x *= -1;
				this.position.x = leftPaddle.getPosition().x + leftPaddle.getSize().w + this.radius;
				break;
			default:
				break;
		}
		let rightPaddle = this.game.getPaddle("right");
		switch(rightPaddle.collideSide(collisionBox)) {
			case "right":
				this.velocity.x *= -1;
				this.position.x = rightPaddle.getPosition().x - this.radius;
				break;
			default:
				break;
		}
	}

	setDead() {
		this.isAlive = false;
	}

	isDead() {
		return !this.isAlive;
	}

	draw(context) {
		context.fillStyle = "#000000";
		context.beginPath();
		context.arc(this.position.x, this.position.y, this.radius, 0, 2 * Math.PI);
		context.fill();
	}

	getBallPositionRatio() {
		return (this.position.y + this.radius) / this.game.getHeight();
	}
}