Pong/Assets/Scripts/Game/Ball.cs

using System;
using Unity.Netcode;
using UnityEngine;

namespace Game {
	public class Ball : NetworkBehaviour {
		public Rigidbody2D Rb { get; private set; }

		private CircleCollider2D Collider { get; set; }
		public float Radius {
			get => transform.localScale.x * Collider.radius;
			set => transform.localScale = new Vector3(1, 1, 1) * value * 2;
		}

		public bool IsAlive {
			get {
				float y = transform.position.y;
				float y1 = BorderSize.Singleton.y1;
				float y2 = BorderSize.Singleton.y2;
				return y > y1 && y < y2;
			}
		}

		private void OnEnable() {
			Rb = GetComponent<Rigidbody2D>();
			Collider = GetComponent<CircleCollider2D>();
		}

		private void Start() {
			Rb.velocity = new Vector2(0, 20);
		}
	}
}