Car-Physics-Godot/Scripts/Core/RotatingComponent.cs

using System;

public abstract class RotatingComponent
{
    public double MomentOfInertia { get; set; }   // kg·m²
    public double AngularVelocity { get; set; }   // rad/s
    public double AngularPosition { get; set; }   // rad (0..2π, wrapped)
    public double TotalAngularPosition { get; set; } // rad (never wraps)
    public double AccumulatedTorque {get; private set; }

    public RotatingComponent(double momentOfInertia = 0.1, double angularVelocity = 0, double angularPosition = 0)
    {
        MomentOfInertia = momentOfInertia;
        AngularVelocity = angularVelocity;
        AngularPosition = angularPosition;
        TotalAngularPosition = angularPosition;
        AccumulatedTorque = 0;
    }

    public virtual void ApplyTorque(double torqueNm)
    {
        AccumulatedTorque += torqueNm;
    }

    public virtual void Update(double dt)
    {
        if (dt <= 0) return;

        if (MomentOfInertia > 0)
        {
            double angularAcceleration = AccumulatedTorque / MomentOfInertia;
            AngularVelocity += angularAcceleration * dt;
        }

        double deltaAngle = AngularVelocity * dt;
        TotalAngularPosition += deltaAngle;
        AngularPosition += deltaAngle;

        // Wrap AngularPosition to 0..2π for sin/cos
        AngularPosition = AngularPosition % (2 * Math.PI);
        if (AngularPosition < 0) AngularPosition += 2 * Math.PI;

        AccumulatedTorque = 0;
    }

    public double RPM => AngularVelocity * 60 / (2 * Math.PI);
    public double TotalAngleDeg => TotalAngularPosition * 180 / Math.PI;

    public void SetRPM(double rpm)
    {
        AngularVelocity = rpm * 2 * Math.PI / 60;
    }

    public virtual void ResetTorque()
    {
        AccumulatedTorque = 0;
    }
}