Merge pull request #505 from peternewell/air-compressor#1

Set compressor to only operate on electric compressor code for v1.4

Author: twpol

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

@@ -2310,14 +2310,21 @@ protected virtual void UpdateVacuumExhauster(float elapsedClockSeconds)
         protected virtual void UpdateCompressor(float elapsedClockSeconds)
         {
 
+            var reservoirChargingRate = MainResChargingRatePSIpS;
+
+            // For a mechanical compressor (typically fitted to a diesel locomotive) the charging rate will be related to the RpM of the diesel engine, and therefore 
+            // derated by an amount equivalent to the diesel RpM.
+            // All other locomotive types it will be the full charging rate for the reservoir
+
+            // TO DO - For v1.4 this code uses the "electric" compressor code to control the compressor. The only additional feature is the addition of a variable 
+            // charging rate based upon the diesel engine rpm. Note that the diesel compressor code operates regardless of whether the engine is running or not. 
+            // This needs to be corrected in a future implementation.
+
+            // If mechanical compressor then calculate charging rate based upon engine rpm
             if (CompressorIsMechanical && (EngineType == EngineTypes.Control || EngineType == EngineTypes.Diesel))
             {
-                // For a mechanical compressor (typically fitted to a diesel locomotive) the charging rate will be related to the RpM of the diesel engine, and therefore 
-                // derated by an amount equivalent to the diesel RpM.
-                // All other locomotive types it will be the full charging rate for the reservoir
-                var reservoirChargingRate = MainResChargingRatePSIpS;
 
-                // Control car uses the attached active locomotive
+                // Control car uses the attached active locomotive to set the charging rate
                 if (EngineType == EngineTypes.Control)
                 {
                     FindControlActiveLocomotive();
@@ -2326,51 +2333,28 @@ protected virtual void UpdateCompressor(float elapsedClockSeconds)
                     {
                         var activeloco = ControlActiveLocomotive as MSTSDieselLocomotive;
 
-                        // Compressors only operate when the diesel engine is running, otherwise they are off
-                        if (activeloco.DieselEngines[0].State == DieselEngineState.Running && !CompressorIsOn)
-                            SignalEvent(Event.CompressorOn);
-                        else if (activeloco.DieselEngines[0].State != DieselEngineState.Running && CompressorIsOn)
-                            SignalEvent(Event.CompressorOff);
-
                         // Set charging rate depending upon compressor rpm
                         reservoirChargingRate = (activeloco.DieselEngines[0].RealRPM / activeloco.DieselEngines[0].MaxRPM) * MainResChargingRatePSIpS;
                     }
                 }
                 else
                 {
-                    // Powered locomotive use thereselves
+                    // Powered locomotive use themselves
                     var mstsDieselLocomotive = this as MSTSDieselLocomotive;
 
-                    // Compressors only operate when the diesel engine is running, otherwise they are off
-                    if (mstsDieselLocomotive.DieselEngines[0].State == DieselEngineState.Running && !CompressorIsOn)
-                        SignalEvent(Event.CompressorOn);
-                    else if (mstsDieselLocomotive.DieselEngines[0].State != DieselEngineState.Running && CompressorIsOn)
-                        SignalEvent(Event.CompressorOff);
-
                     // Set charging rate depending upon compressor rpm
                     reservoirChargingRate = (mstsDieselLocomotive.DieselEngines[0].RealRPM / mstsDieselLocomotive.DieselEngines[0].MaxRPM) * MainResChargingRatePSIpS;
                 }
-
-                // Only change reservoir pressure if compressor is running
-                if (CompressorIsOn)
-                {
-                    MainResPressurePSI += elapsedClockSeconds * reservoirChargingRate;
-                }
-
-                // Compressor runs continuously, and excess air pressure is exhausted to atmosphere once max pressure is reached.
-                MainResPressurePSI = MathHelper.Clamp(MainResPressurePSI, 0.0f, MaxMainResPressurePSI);
-
             }
-            else // Non-mechanical compressors
-            {
-                if (MainResPressurePSI < CompressorRestartPressurePSI && LocomotivePowerSupply.AuxiliaryPowerSupplyState == PowerSupplyState.PowerOn && !CompressorIsOn)
-                    SignalEvent(Event.CompressorOn);
-                else if ((MainResPressurePSI > MaxMainResPressurePSI || LocomotivePowerSupply.AuxiliaryPowerSupplyState != PowerSupplyState.PowerOn) && CompressorIsOn)
-                    SignalEvent(Event.CompressorOff);
 
-                if (CompressorIsOn)
-                    MainResPressurePSI += elapsedClockSeconds * MainResChargingRatePSIpS;
-            }
+            // Turn compressor on and off
+            if (MainResPressurePSI < CompressorRestartPressurePSI && LocomotivePowerSupply.AuxiliaryPowerSupplyState == PowerSupplyState.PowerOn && !CompressorIsOn)
+                SignalEvent(Event.CompressorOn);
+            else if ((MainResPressurePSI > MaxMainResPressurePSI || LocomotivePowerSupply.AuxiliaryPowerSupplyState != PowerSupplyState.PowerOn) && CompressorIsOn)
+                SignalEvent(Event.CompressorOff);
+
+            if (CompressorIsOn)
+                MainResPressurePSI += elapsedClockSeconds * reservoirChargingRate;
         }
 
         /// <summary>