cirnogodot/Scripts/Components/FSM/3DPlayer/IsoMovementModule.cs

using Cirno.Scripts.Components.Actors;
using Cirno.Scripts.Components.Actors._3D;
using Cirno.Scripts.Utils;
using Godot;
using GodotPlugins.Game;

namespace Cirno.Scripts.Components.FSM._3DPlayer;

public partial class IsoMovementModule : ModuleBase<PlayerState, CharacterBody3D>
{
    [Export] public IsoPlayerStorageModule PlayerStorage { get; private set; }
    [Export] private InputProvider _inputProvider;

    [Export] public PlayerHitboxSpriteProvider3D HitboxSpriteProvider { get; private set; }

    [Export] public int Speed { get; set; } = 45;
    [Export] public int StrafeSpeed { get; set; } = 35;
    [Export] public float Acceleration = 8f;
    [Export] public float Deceleration = 8f;
    [Export] public float Gravity = -9.8f;
    [Export] public float FallSpeed = 20f;

    [Export] public float TurnResistance { get; set; } = 0.5f;

    private bool _isStrafing;
    private float _accelerationPerSecond;
    private float _decelerationPerSecond;

    public int MovementSpeed => _isStrafing ? StrafeSpeed : Speed;

    private IStateMachine<PlayerState, CharacterBody3D> _stateMachine;
    private CharacterBody3D MainObject => _stateMachine.MainObject;

    public override void EnterState(PlayerState state)
    {
        _accelerationPerSecond = Speed / Acceleration;
        _decelerationPerSecond = Speed / Deceleration;
    }

    public override void ExitState(PlayerState state)
    {
    }

    public override void Init(IStateMachine<PlayerState, CharacterBody3D> machine)
    {
        _stateMachine = machine;
    }

    public override void Process(double delta)
    {
        var movementInput = _inputProvider.GetMovementInput();

        _isStrafing = _inputProvider.GetStrafePressed();
        var rightStickInput = _inputProvider.GetAimInput().Normalized();

        // Update Facing Direction
        // if (!_isStrafing)
        // {
        if (rightStickInput.Length() > 0.1f) // If the right stick is moved
        {
            PlayerStorage.FacingDirection = rightStickInput;
            PlayerStorage.AimingDirection = rightStickInput;
        }
        else if (movementInput != Vector2.Zero) // Fall back to movement direction
        {
            PlayerStorage.FacingDirection = movementInput;
            PlayerStorage.AimingDirection = rightStickInput;
        }
        // }

        var rotatedMovementDirection = movementInput.Rotated(Mathf.DegToRad(-45f));

        //PlayerStorage.MovementDirection = new Vector3(rotatedMovementDirection.X, 0, rotatedMovementDirection.Y);
        PlayerStorage.MovementDirection = rotatedMovementDirection;

        HitboxSpriteProvider.SetVisibility(_isStrafing);
    }

    private Vector2 InterpolateVelocityAxes(
        Vector2 current, Vector2 target, float accel, float decel, float delta)
    {
        float newX = current.X;
        float newY = current.Y;

        // --- X Axis ---
        if (Mathf.Sign(target.X) == Mathf.Sign(current.X) || Mathf.IsZeroApprox(current.X))
        {
            // Same direction or stopped → normal accel/decel
            float step = (Mathf.Abs(target.X) > Mathf.Abs(current.X)) ? accel : decel;
            newX = Mathf.MoveToward(current.X, target.X, step * delta);
        }
        else
        {
            // Opposite direction → apply resistance multiplier to deceleration
            float slowStep = decel * TurnResistance;
            newX = Mathf.MoveToward(current.X, 0, slowStep * delta);

            // Only start accelerating toward target if we've nearly stopped
            if (Mathf.IsZeroApprox(newX))
                newX = Mathf.MoveToward(newX, target.X, accel * delta);
        }

        // --- Y Axis ---
        if (Mathf.Sign(target.Y) == Mathf.Sign(current.Y) || Mathf.IsZeroApprox(current.Y))
        {
            float step = (Mathf.Abs(target.Y) > Mathf.Abs(current.Y)) ? accel : decel;
            newY = Mathf.MoveToward(current.Y, target.Y, step * delta);
        }
        else
        {
            float slowStep = decel * TurnResistance;
            newY = Mathf.MoveToward(current.Y, 0, slowStep * delta);

            if (Mathf.IsZeroApprox(newY))
                newY = Mathf.MoveToward(newY, target.Y, accel * delta);
        }

        return new Vector2(newX, newY);
    }

    public override void PhysicsProcess(double delta)
    {
        var v3 = MainObject.Velocity;
        Vector2 v = v3.ToVector2();
        float dt = (float)delta;

        Vector2 inputDir = PlayerStorage.MovementDirection;
        if (inputDir.Length() > 1f)
            inputDir = inputDir.Normalized();

        if (_isStrafing)
        {
            v = inputDir * StrafeSpeed;
        }
        else
        {
            Vector2 targetVel = inputDir * Speed;
            v = InterpolateVelocityAxes(v, targetVel, Acceleration, Deceleration, dt);
        }

        float vy = Mathf.Clamp(v3.Y + Gravity * dt, -FallSpeed, FallSpeed);
        if (Input.IsKeyLabelPressed(Key.Z)) vy = 10;

        MainObject.Velocity = v.ToVector3(vy);
        MainObject.MoveAndSlide();
    }
}