ScienceLab.GravityForce/Assets/Materials/Scripts/MoonOrbitSaturn.cs

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class MoonOrbitSaturn : MonoBehaviour
{
    public Transform saturn;

    public SaturnMoonType moonType = SaturnMoonType.Mimas;
    public bool autoCalculateOrbit = true;
    public float manualOrbitRadius = 10f;

    public float orbitInclination = 0f;
    public float startAngleDegrees = 0f;

    public float timeScale = 10f;

    public float orbitScaleMultiplier = 4f;

    public bool showDebugInfo = false;

    private const float SATURN_RADIUS_KM = 58232f;

    private const float MIMAS_DISTANCE_KM = 185539f;
    private const float MIMAS_PERIOD_HOURS = 22.6f;

    private const float ENCELADUS_DISTANCE_KM = 237948f;
    private const float ENCELADUS_PERIOD_HOURS = 32.9f;

    private const float TETHYS_DISTANCE_KM = 294619f;
    private const float TETHYS_PERIOD_HOURS = 45.3f;

    private const float DIONE_DISTANCE_KM = 377396f;
    private const float DIONE_PERIOD_HOURS = 65.7f;

    private const float RHEA_DISTANCE_KM = 527108f;
    private const float RHEA_PERIOD_HOURS = 108.4f;

    private const float TITAN_DISTANCE_KM = 1221870f;
    private const float TITAN_PERIOD_HOURS = 382.7f;

    private const float IAPETUS_DISTANCE_KM = 3560820f;
    private const float IAPETUS_PERIOD_HOURS = 1903.7f;

    private float orbitRadius;
    private float angularSpeed;
    private float currentAngle;

    public enum SaturnMoonType
    {
        Mimas,
        Enceladus,
        Tethys,
        Dione,
        Rhea,
        Titan,
        Iapetus
    }

    void Start()
    {
        if (saturn == null)
        {
            saturn = GameObject.Find("Saturn")?.transform;
            if (saturn == null)
            {
                enabled = false;
                return;
            }
        }

        CalculateOrbit();
        SetInitialPosition();
    }

    void CalculateOrbit()
    {
        float saturnRadius = saturn.localScale.x / 2f;

        if (autoCalculateOrbit)
        {
            switch (moonType)
            {
                case SaturnMoonType.Mimas:
                    orbitRadius = saturnRadius * (MIMAS_DISTANCE_KM / SATURN_RADIUS_KM);
                    angularSpeed = (2f * Mathf.PI / (MIMAS_PERIOD_HOURS * 3600f)) * timeScale;
                    orbitInclination = 1.57f;
                    break;

                case SaturnMoonType.Enceladus:
                    orbitRadius = saturnRadius * (ENCELADUS_DISTANCE_KM / SATURN_RADIUS_KM);
                    angularSpeed = (2f * Mathf.PI / (ENCELADUS_PERIOD_HOURS * 3600f)) * timeScale;
                    orbitInclination = 0.02f;
                    break;

                case SaturnMoonType.Tethys:
                    orbitRadius = saturnRadius * (TETHYS_DISTANCE_KM / SATURN_RADIUS_KM);
                    angularSpeed = (2f * Mathf.PI / (TETHYS_PERIOD_HOURS * 3600f)) * timeScale;
                    orbitInclination = 1.09f;
                    break;

                case SaturnMoonType.Dione:
                    orbitRadius = saturnRadius * (DIONE_DISTANCE_KM / SATURN_RADIUS_KM);
                    angularSpeed = (2f * Mathf.PI / (DIONE_PERIOD_HOURS * 3600f)) * timeScale;
                    orbitInclination = 0.02f;
                    break;

                case SaturnMoonType.Rhea:
                    orbitRadius = saturnRadius * (RHEA_DISTANCE_KM / SATURN_RADIUS_KM);
                    angularSpeed = (2f * Mathf.PI / (RHEA_PERIOD_HOURS * 3600f)) * timeScale;
                    orbitInclination = 0.35f;
                    break;

                case SaturnMoonType.Titan:
                    orbitRadius = saturnRadius * (TITAN_DISTANCE_KM / SATURN_RADIUS_KM);
                    angularSpeed = (2f * Mathf.PI / (TITAN_PERIOD_HOURS * 3600f)) * timeScale;
                    orbitInclination = 0.33f;
                    break;

                case SaturnMoonType.Iapetus:
                    orbitRadius = saturnRadius * (IAPETUS_DISTANCE_KM / SATURN_RADIUS_KM);
                    angularSpeed = (2f * Mathf.PI / (IAPETUS_PERIOD_HOURS * 3600f)) * timeScale;
                    orbitInclination = 15.47f;
                    break;
            }

            orbitRadius *= orbitScaleMultiplier;
        }
        else
        {
            orbitRadius = manualOrbitRadius;
            float period = GetPeriod() * 3600f;
            angularSpeed = (2f * Mathf.PI / period) * timeScale;
        }
    }

    float GetPeriod()
    {
        switch (moonType)
        {
            case SaturnMoonType.Mimas: return MIMAS_PERIOD_HOURS;
            case SaturnMoonType.Enceladus: return ENCELADUS_PERIOD_HOURS;
            case SaturnMoonType.Tethys: return TETHYS_PERIOD_HOURS;
            case SaturnMoonType.Dione: return DIONE_PERIOD_HOURS;
            case SaturnMoonType.Rhea: return RHEA_PERIOD_HOURS;
            case SaturnMoonType.Titan: return TITAN_PERIOD_HOURS;
            case SaturnMoonType.Iapetus: return IAPETUS_PERIOD_HOURS;
            default: return MIMAS_PERIOD_HOURS;
        }
    }

    void SetInitialPosition()
    {
        currentAngle = startAngleDegrees * Mathf.Deg2Rad;
        UpdatePosition();
    }

    void Update()
    {
        currentAngle += angularSpeed * Time.deltaTime;
        UpdatePosition();
    }

    void UpdatePosition()
    {
        float x = Mathf.Cos(currentAngle) * orbitRadius;
        float z = Mathf.Sin(currentAngle) * orbitRadius;

        float inclinationRad = orbitInclination * Mathf.Deg2Rad;
        float y = z * Mathf.Sin(inclinationRad);
        z = z * Mathf.Cos(inclinationRad);

        transform.position = saturn.position + new Vector3(x, y, z);
    }

    void OnDrawGizmos()
    {
        if (saturn == null) return;

        Gizmos.color = Color.white;

        int segments = 64;
        Vector3 prevPos = GetOrbitPoint(0f);

        for (int i = 1; i <= segments; i++)
        {
            Vector3 newPos = GetOrbitPoint(i * 2f * Mathf.PI / segments);
            Gizmos.DrawLine(prevPos, newPos);
            prevPos = newPos;
        }
    }

    Vector3 GetOrbitPoint(float angle)
    {
        float x = Mathf.Cos(angle) * orbitRadius;
        float z = Mathf.Sin(angle) * orbitRadius;

        float inclinationRad = orbitInclination * Mathf.Deg2Rad;
        float y = z * Mathf.Sin(inclinationRad);
        z = z * Mathf.Cos(inclinationRad);

        return saturn.position + new Vector3(x, y, z);
    }
}