*

Unity/Assets/Scripts/Car/CarEngine.cs

@@ -0,0 +1,110 @@
+using UnityEngine;
+using System.Collections;
+using System;
+using System.Collections.Generic;
+
+[Serializable]
+public class IdleThrolleController
+{
+    public double IdleSpeed;
+    public double SpeedThreshold = 1.0;
+    public double LagConstant = 1.0;
+    public double IdleThrolle = 0.0;
+
+    public void Integrate(double dt, double speed)
+    {
+        var throlleDerivative = ((0.5f*(1.0 - Math.Tanh(4.0*(speed - IdleSpeed)/SpeedThreshold))) - IdleThrolle)/LagConstant;
+        IdleThrolle += throlleDerivative * dt;
+    }
+}
+
+public class CarEngine : MonoBehaviour {
+    public Flywheel flywheel;
+	public int cylinderCount = 4;
+	public float startRpm = 50;
+
+    public double inertia = 0.3f;
+    public double inputInertia = 0.0;
+    public double inputTorque = 0.0;
+
+    /*public abstract Curve TorqueCurve { get;}
+	public abstract Curve FrictionCurve { get;}*/
+    public float Weight = 100;
+
+	public Starter starter;
+
+    public double inputThrolle = 0.0f;
+    public double engineThrolle = 0.0f;
+    public IdleThrolleController idleThrolleController;
+    public double crankshaftAngle = 0.0; //radians
+    public double angularSpeed;
+    public double angularSpeedRPM;
+    public double k_Friction = 0.000003;
+
+    public Curve powerCurve;
+
+    public double k_FrictionTorque = 0.75f;
+    public double kinematicFrictionTorque = 0;
+
+    public double Rpm
+    {
+        get { return angularSpeed * MathEx.RadSToRpm; }
+    }
+
+
+   /* private static KeyValuePair<int, float>[] _starterTable = new KeyValuePair<int, float>[]{
+		new KeyValuePair<int, float>(2, 12.5f),
+		new KeyValuePair<int, float>(4, 8.0f),
+		new KeyValuePair<int, float>(6, 6.5f),
+		new KeyValuePair<int, float>(8, 6.0f),
+		new KeyValuePair<int, float>(12, 5.5f)
+	};*/
+
+
+    void FixedUpdate()
+    {
+        Integrate(Time.fixedDeltaTime);
+    }
+
+    public void Integrate(double dt) {
+        //do idle throlle
+        idleThrolleController.Integrate(dt, Rpm);
+        engineThrolle = Math.Max(inputThrolle, idleThrolleController.IdleThrolle);
+
+        //integrate angular acceleration and speed
+        var angularDerivative = (GetTorque(engineThrolle, Rpm) - inputTorque) / (inertia + inputInertia);
+        angularSpeed += angularDerivative * dt;
+
+        angularSpeedRPM = MathEx.RadSToRpm * angularSpeed;
+
+        //integrate angle
+        crankshaftAngle += angularSpeed * dt;
+
+        kinematicFrictionTorque = (angularSpeedRPM/60.0)*k_FrictionTorque;
+    }
+
+    public double GetTorque(double throlle, double rpm)
+    {
+        var t = GetTorque(rpm);
+        t = t * throlle - k_Friction * rpm * rpm * (1.0 - throlle);
+        return t; 
+    }
+
+    public double GetTorque(double rpm){
+        if (powerCurve == null)
+        {
+            return 0;
+        }
+        return powerCurve.Sample((float)rpm);
+    }
+
+	public static float GetWatts(float torque, float rpm){
+		return torque * rpm / 9549.0f;
+	}
+
+	public static float GetHp(float torque, float rpm){
+		return GetWatts(torque, rpm) * 1.36f;
+	}
+
+	public bool Started = false;
+}