ScienceLab.FrictionForce/Assets/Scripts/Rocket/RocketFlightCore.cs

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

public class RocketFlightCore : MonoBehaviour
{
    public enum FlightPhase
    {
        Idle, Ignition, LaunchPad, LowerAtmosphere, UpperAtmosphere, KarmanLine, Space, DeepSpace, Exploded, Landed
    }

    public FlightPhase Phase { get; private set; } = FlightPhase.Idle;
    public float CurrentHeight { get; private set; }
    public float Velocity { get; private set; }
    public float MaxHeightReached { get; private set; }
    public float AnimTime { get; private set; }
    public bool FuelCutoff { get; private set; }
    public bool RocketEscaped { get; private set; }
    public bool IsActive { get; private set; }
    public float TotalFuel { get; private set; }
    public float RemainingFuel { get; private set; }

    private float _gravity;
    private float _atmDensity;
    private float _materialDrag;
    private float _thrust;
    private float _animSpeed;
    private float _fuelBurnRate;
    private bool _willExplode;
    private float _explodeDelay;
    private float _explodeTimer;
    private float _fuelCutoffTime;
    private float _escapeVelocity;

    public void Initialize() { }

    public void StartFlight(float fuelAmount, float gravity, float atmDensity, float materialDrag, bool willExplode, float explodeDelay)
    {
        _gravity = gravity;
        _atmDensity = atmDensity;
        _materialDrag = materialDrag;
        _willExplode = willExplode;
        _explodeDelay = explodeDelay;

        _thrust = Mathf.Max(10f, 200f - atmDensity * 1.5f - materialDrag * 30f);
        _fuelBurnRate = 1f;
        TotalFuel = fuelAmount;
        RemainingFuel = fuelAmount;

        _escapeVelocity = Mathf.Sqrt(2f * gravity * 6371000f) * 0.0001f;

        float simFuelDuration = fuelAmount / _fuelBurnRate;
        _animSpeed = simFuelDuration / 18f;

        CurrentHeight = 0f;
        Velocity = 0f;
        MaxHeightReached = 0f;
        AnimTime = 0f;
        FuelCutoff = false;
        RocketEscaped = false;
        IsActive = true;
        _explodeTimer = 0f;
        _fuelCutoffTime = 0f;

        Phase = FlightPhase.Ignition;
    }

    public void ResetFlight()
    {
        CurrentHeight = 0f;
        Velocity = 0f;
        MaxHeightReached = 0f;
        AnimTime = 0f;
        FuelCutoff = false;
        RocketEscaped = false;
        IsActive = false;
        RemainingFuel = 0f;
        Phase = FlightPhase.Idle;
    }

    public bool UpdateFlight(float deltaTime, out bool shouldExplode, out bool flightFinished)
    {
        shouldExplode = false;
        flightFinished = false;

        if (!IsActive) return false;

        AnimTime += deltaTime;
        float dt = deltaTime * _animSpeed;

        if (_willExplode)
        {
            _explodeTimer += deltaTime;
            if (_explodeTimer >= _explodeDelay)
            {
                shouldExplode = true;
                Phase = FlightPhase.Exploded;
                IsActive = false;
                return true;
            }
        }

        bool hasFuel = RemainingFuel > 0f;
        float currentThrust = 0f;

        if (hasFuel && !FuelCutoff)
        {
            currentThrust = _thrust;
            RemainingFuel = Mathf.Max(0f, RemainingFuel - _fuelBurnRate * dt);
            if (RemainingFuel <= 0f)
            {
                FuelCutoff = true;
                _fuelCutoffTime = AnimTime;
            }
        }

        float atmFactor = Mathf.Exp(-CurrentHeight * 0.00001f);
        float drag = _atmDensity * atmFactor * Velocity * Velocity * _materialDrag * 0.0001f;
        drag = Mathf.Sign(Velocity) * drag;

        Velocity += (currentThrust - _gravity - drag) * dt;

        CurrentHeight = Mathf.Max(0f, CurrentHeight + Velocity * dt);
        if (CurrentHeight > MaxHeightReached) MaxHeightReached = CurrentHeight;

        if (FuelCutoff && Velocity > _escapeVelocity * 0.5f)
            RocketEscaped = true;

        UpdatePhase();

        if (AnimTime >= 25f || (FuelCutoff && CurrentHeight <= 0f && Velocity < 0f))
        {
            if (FuelCutoff && CurrentHeight <= 0f && Velocity < 0f)
            {
                shouldExplode = true;
                Phase = FlightPhase.Exploded;
            }
            else
            {
                flightFinished = true;
            }
            IsActive = false;
            return true;
        }

        return false;
    }

    private void UpdatePhase()
    {
        if (AnimTime < 0.5f)
            Phase = FlightPhase.Ignition;
        else if (CurrentHeight < 1000f)
            Phase = FlightPhase.LaunchPad;
        else if (CurrentHeight < 30000f)
            Phase = FlightPhase.LowerAtmosphere;
        else if (CurrentHeight < 80000f)
            Phase = FlightPhase.UpperAtmosphere;
        else if (CurrentHeight < 100000f)
            Phase = FlightPhase.KarmanLine;
        else if (CurrentHeight < 400000f)
            Phase = FlightPhase.Space;
        else
            Phase = FlightPhase.DeepSpace;
    }

    public float GetAtmosphereProgress()
    {
        return Mathf.Clamp01(CurrentHeight / 100000f);
    }

    public float GetSpaceProgress()
    {
        return Mathf.Clamp01((CurrentHeight - 100000f) / 300000f);
    }

    public float GetSpeedNormalized()
    {
        return Mathf.Clamp01(Mathf.Abs(Velocity) / 150f);
    }

    public float GetFuelProgress()
    {
        return TotalFuel > 0f ? 1f - (RemainingFuel / TotalFuel) : 1f;
    }

    public float GetFuelCutoffTime()
    {
        return FuelCutoff ? AnimTime - _fuelCutoffTime : 0f;
    }
}