Duplex steam engines - Booster Engine addition

Author: peternewell

Source/Orts.Simulation/Simulation/RollingStocks/MSTSControlTrailerCar.cs

@@ -225,7 +225,7 @@ public override string GetStatus()
         /// <summary>
         /// This function updates periodically the locomotive's motive force.
         /// </summary>
-        protected override void UpdateTractiveForce(float elapsedClockSeconds, float t, float AbsSpeedMpS, float AbsWheelSpeedMpS)
+        protected override void UpdateTractiveForce(float elapsedClockSeconds, float t, float AbsSpeedMpS, float AbsWheelSpeedMpS, int numberofengine)
         {
         }
 

Source/Orts.Simulation/Simulation/RollingStocks/MSTSDieselLocomotive.cs

@@ -624,7 +624,7 @@ protected override void UpdateControllers(float elapsedClockSeconds)
         /// <summary>
         /// This function updates periodically the locomotive's motive force.
         /// </summary>
-        protected override void UpdateTractiveForce(float elapsedClockSeconds, float t, float AbsSpeedMpS, float AbsWheelSpeedMpS)
+        protected override void UpdateTractiveForce(float elapsedClockSeconds, float t, float AbsSpeedMpS, float AbsWheelSpeedMpS, int numberofengine)
         {
             // This section calculates the motive force of the locomotive as follows:
             // Basic configuration (no TF table) - uses P = F /speed  relationship - requires power and force parameters to be set in the ENG file. 
@@ -760,7 +760,7 @@ protected override void UpdateTractiveForce(float elapsedClockSeconds, float t,
                 DieselEngines.HandleEvent(PowerSupplyEvent.StopEngine);
             }
 
-            ApplyDirectionToTractiveForce();
+            ApplyDirectionToTractiveForce(ref TractiveForceN);
 
             // Calculate the total tractive force for the locomotive - ie Traction + Dynamic Braking force.
             // Note typically only one of the above will only ever be non-zero at the one time.

Source/Orts.Simulation/Simulation/RollingStocks/MSTSLocomotive.cs

@@ -2008,9 +2008,12 @@ public override void Update(float elapsedClockSeconds)
 
             // Cruise Control
             CruiseControl?.Update(elapsedClockSeconds);
- 
-            // TODO  this is a wild simplification for electric and diesel electric
-            UpdateTractiveForce(elapsedClockSeconds, ThrottlePercent / 100f, AbsSpeedMpS, AbsWheelSpeedMpS);
+
+            if (EngineType == EngineTypes.Diesel || EngineType == EngineTypes.Electric)
+            {
+                // TODO  this is a wild simplification for electric and diesel electric
+                UpdateTractiveForce(elapsedClockSeconds, ThrottlePercent / 100f, AbsSpeedMpS, AbsWheelSpeedMpS, 0);
+            }
 
             foreach (MultiPositionController mpc in MultiPositionControllers)
             {
@@ -2372,7 +2375,7 @@ protected virtual void UpdateControllers(float elapsedClockSeconds)
         /// <summary>
         /// This function updates periodically the locomotive's motive force.
         /// </summary>
-        protected virtual void UpdateTractiveForce(float elapsedClockSeconds, float t, float AbsSpeedMpS, float AbsWheelSpeedMpS)
+        protected virtual void UpdateTractiveForce(float elapsedClockSeconds, float t, float AbsSpeedMpS, float AbsWheelSpeedMpS, int numberofengine)
         {
             // Method to set force and power info
             // An alternative method in the steam locomotive will override this and input force and power info for it.
@@ -2438,7 +2441,7 @@ protected virtual void UpdateTractiveForce(float elapsedClockSeconds, float t, f
                 AverageForceN = w * AverageForceN + (1 - w) * TractiveForceN;
             }
 
-            ApplyDirectionToTractiveForce();
+            ApplyDirectionToTractiveForce(ref TractiveForceN);
 
             // Calculate the total tractive force for the locomotive - ie Traction + Dynamic Braking force.
             // Note typically only one of the above will only ever be non-zero at the one time.
@@ -2493,21 +2496,21 @@ protected virtual void UpdateAxleDriveForce()
         /// <summary>
         /// This function applies a sign to the motive force as a function of the direction of the train.
         /// </summary>
-        protected virtual void ApplyDirectionToTractiveForce()
+        protected virtual void ApplyDirectionToTractiveForce(ref float tractiveForceN)
         {
             if (Train.IsPlayerDriven)
             {
                 switch (Direction)
                 {
                     case Direction.Forward:
-                        //MotiveForceN *= 1;     //Not necessary
+                        //tractiveForceN *= 1;     //Not necessary
                         break;
                     case Direction.Reverse:
-                        TractiveForceN *= -1;
+                        tractiveForceN *= -1;
                         break;
                     case Direction.N:
                     default:
-                        TractiveForceN *= 0;
+                        tractiveForceN *= 0;
                         break;
                 }
             }
@@ -2516,7 +2519,7 @@ protected virtual void ApplyDirectionToTractiveForce()
                 switch (Direction)
                 {
                     case Direction.Reverse:
-                        TractiveForceN *= -1;
+                        tractiveForceN *= -1;
                         break;
                     default:
                         break;