using UnityEngine;
using System.Collections;

public class Rocket : MonoBehaviour {
    public Transform[] planets;
    public float speed = 20;
    public float rotspeed = 1;
    private Vector2 gravity = new Vector2(0, 0);

    void FixedUpdate ()
    {
        //Gravity
        foreach (Transform planet in planets)
        {
            Vector2 pos = new Vector2(transform.position.x, transform.position.y);
            Vector2 planetpos = new Vector2(planet.position.x, planet.position.y);
            gravity = planet.GetComponent<Planet>().mass * (planetpos - pos) / (Distance(pos, planetpos) * Distance(pos, planetpos));
            rigidbody2D.AddForce(gravity);
        }

        //Thrust
        if (Input.GetAxis("Vertical") > 0)
        {
            rigidbody2D.AddForce(transform.up * Input.GetAxis("Vertical") * speed);
        }
        rigidbody2D.AddTorque(-Input.GetAxis("Horizontal") * rotspeed);
    }

    float Distance(Vector2 pos1, Vector2 pos2)
    {
        float csquared = (pos1.x - pos2.x) * (pos1.x - pos2.x) + (pos1.y - pos2.y) * (pos1.y - pos2.y);
        return Mathf.Sqrt(csquared);
    }
}