fix: clean gitignore for Godot C#

Scripts/Components/Engine.cs

@@ -0,0 +1,131 @@
+using System;
+
+public class Engine : RotatingComponent
+{
+    public double ThrottlePosition { get; set; }
+    public double CurrentPower { get; private set; }
+    public double CombustionPower { get; private set; }
+    public int CylinderCount { get; private set; }
+    public EngineControlUnit Ecu = new EngineControlUnit();
+
+    // Friction
+    private const double _baseFriction = 12.0;      // Seals, oil pump, valvetrain (Nm)
+    private const double _linearFriction = 0.025;   // Hydrodynamic bearing drag (Nm/(rad/s))
+    private const double _quadraticFriction = 0.00002; // Windage & churning (Nm/(rad/s)²)
+
+    // Engine geometry
+    private double _displacementCC;
+    private double _compressionRatio;
+
+    // Volumetric efficiency tuning – now in rad/s
+    public double VolumetricEfficiencyPeak { get; set; } = 1.15;      // was 1.10
+    public double AngularVelocityForVEPeak { get; set; } = 550.0;    // 5250 RPM (rad/s = 550)
+    public double AngularVelocityForVEMin { get; set; } = 800.0;      // 7639 RPM
+    public double VEminAtRedline { get; set; } = 0.85;                // much higher at redline
+
+    // Physics constants
+    private const double ATM_PRESSURE_KPA = 101.3;
+    private const double AIR_DENSITY_KG_PER_M3 = 1.225;
+    private const double FUEL_HEAT_VALUE_J_PER_KG = 43e6;
+    private const double STOICHIOMETRIC_AIR_FUEL_RATIO = 14.7;
+
+    public Engine(double inertia, int cylinders, double displacementCC, double compressionRatio)
+    {
+        CylinderCount = cylinders;
+        _displacementCC = displacementCC;
+        _compressionRatio = compressionRatio;
+
+        MomentOfInertia = inertia;
+        AngularVelocity = 100;   // rad/s (~955 RPM)
+    }
+
+    public override void Update(double dt)
+    {
+        Ecu.Update(dt, this);
+
+        ApplyThrottleTorque();
+        ApplyFrictionTorque();
+
+        CurrentPower = AccumulatedTorque * AngularVelocity;
+
+        base.Update(dt);
+    }
+
+    private double ComputeIndicatedTorque()
+    {
+        double w = AngularVelocity;           // rad/s
+        double throttle = Math.Clamp(ThrottlePosition, 0.0, 1.0);
+
+        // Volumetric Efficiency (WOT) as function of w (rad/s)
+        double veWOT;
+        if (w <= AngularVelocityForVEPeak)
+        {
+            // Start at a realistic 0.75 at zero RPM, peaking at your target
+            double t = w / AngularVelocityForVEPeak;
+            veWOT = 0.75 + (VolumetricEfficiencyPeak - 0.75) * t * (2 - t);
+        }
+        else
+        {
+            // Linear drop from VE_peak to VEminAtRedline
+            double t = (w - AngularVelocityForVEPeak) / (AngularVelocityForVEMin - AngularVelocityForVEPeak);
+            t = Math.Clamp(t, 0.0, 1.0);
+            veWOT = VolumetricEfficiencyPeak - t * (VolumetricEfficiencyPeak - VEminAtRedline);
+        }
+        veWOT = Math.Clamp(veWOT, 0.25, VolumetricEfficiencyPeak);
+
+        // Intake loss
+        double maxEngineDemandSpeed = 700.0; // rad/s, roughly 6700 RPM
+        double throttleArea = Math.Pow(throttle, 1.5);
+        double engineDemand = (w / maxEngineDemandSpeed) * veWOT;
+
+        const double intakeResistance = 0.03;   // was 0.5 – now physically realistic
+        double mapFraction = throttleArea / (throttleArea + intakeResistance * engineDemand);
+
+        if (throttle == 0) mapFraction = 0;
+
+        double manifoldPressureKpa = ATM_PRESSURE_KPA * mapFraction;
+        manifoldPressureKpa = Math.Clamp(manifoldPressureKpa, 0, ATM_PRESSURE_KPA);
+
+        double veActual = veWOT * (manifoldPressureKpa / ATM_PRESSURE_KPA);
+
+        // Exhaust loss (backpressure)
+        double exhaustBackpressureKpa = 2.0e-5 * w * w;
+        double exhaustLossFactor = 1.0 - Math.Min(0.25, exhaustBackpressureKpa / ATM_PRESSURE_KPA);
+
+        // Air & fuel mass per cycle
+        double displacementM3 = _displacementCC * 1e-6;
+        double airMassPerCycleKg = veActual * AIR_DENSITY_KG_PER_M3 * displacementM3;
+        double fuelMassPerCycleKg = airMassPerCycleKg / STOICHIOMETRIC_AIR_FUEL_RATIO;
+        double energyPerCycleJ = fuelMassPerCycleKg * FUEL_HEAT_VALUE_J_PER_KG;
+
+        // Thermal efficiency
+        double gamma = 1.4;
+        double ottoEfficiency = 1.0 - 1.0 / Math.Pow(_compressionRatio, gamma - 1.0);
+        double thermalEfficiency = 0.65 * ottoEfficiency;
+
+        double workPerCycleJ = energyPerCycleJ * thermalEfficiency * exhaustLossFactor;
+
+        double indicatedTorque = workPerCycleJ / (4.0 * Math.PI);
+        indicatedTorque = Math.Min(600.0, Math.Max(0.0, indicatedTorque));
+
+        return indicatedTorque;
+    }
+
+    public void ApplyThrottleTorque()
+    {
+        double torque = ComputeIndicatedTorque();
+        CombustionPower = torque * AngularVelocity;
+        ApplyTorque(torque);
+    }
+
+    public void ApplyFrictionTorque()
+    {
+        // Friction uses angular velocity (rad/s) directly
+        double w = AngularVelocity;
+        double frictionMag = _baseFriction
+                             + _linearFriction * Math.Abs(w)
+                             + _quadraticFriction * w * w;
+        double frictionTorque = -Math.Sign(w) * frictionMag;
+        ApplyTorque(frictionTorque);
+    }
+}