Add distributing valve

Author: cesarBLG

Source/Orts.Simulation/Common/Scripting/BrakeController.cs

@@ -359,6 +359,8 @@ public enum ControllerState
         SMEFullServ,        // TrainBrakesControllerSMEFullServiceStart
         SMESelfLap,         // TrainBrakesControllerSMEHoldStart
         SMEReleaseStart,    // TrainBrakesControllerSMEReleaseStart
+        HoldEngine,        // TrainBrakesControllerHoldEngineStart
+        BailOff,            // EngineBrakesControllerBailOffStart
     };
 
     public static class ControllerStateDictionary
@@ -405,7 +407,9 @@ public static class ControllerStateDictionary
             {ControllerState.SMEOnly, Catalog.GetString("SME Service")},
             {ControllerState.SMEFullServ, Catalog.GetString("SME Full Service")},
             {ControllerState.SMESelfLap, Catalog.GetString("SME Self Lap")},
-            {ControllerState.SMEReleaseStart, Catalog.GetString("SME Release Start")}
+            {ControllerState.SMEReleaseStart, Catalog.GetString("SME Release Start")},
+            {ControllerState.HoldEngine, Catalog.GetString("Hold Engine")},
+            {ControllerState.BailOff, Catalog.GetString("Bail Off")}
         };
     }
 }

Source/Orts.Simulation/Simulation/RollingStocks/MSTSWagon.cs

@@ -227,6 +227,7 @@ public enum BrakeValveType
             None,
             TripleValve, // Plain triple valve
             Distributor, // Triple valve with graduated release
+            DistributingValve, // Triple valve + driver brake valve control. Only for locomotives
         }
         /// <summary>
         /// Type of brake valve in the car
@@ -1190,6 +1191,7 @@ public virtual void Parse(string lowercasetoken, STFReader stf)
                             case "triple_valve": BrakeValve = BrakeValveType.TripleValve; break;
                             case "distributor":
                             case "graduated_release_triple_valve": BrakeValve = BrakeValveType.Distributor; break;
+                            case "distributing_valve": BrakeValve = BrakeValveType.DistributingValve; break;
                             case "emergency_brake_reservoir": EmergencyReservoirPresent = true; break;
                             case "handbrake": HandBrakePresent = true; break;
                             case "auxilary_reservoir": // MSTS legacy parameter - use is discouraged

Source/Orts.Simulation/Simulation/RollingStocks/SubSystems/Brakes/MSTS/AirSinglePipe.cs

@@ -517,36 +517,73 @@ public override void Update(float elapsedClockSeconds)
             if (AutoCylPressurePSI < 0)
                 AutoCylPressurePSI = 0;
 
-            bool bailoff = false;
+            if (Car is MSTSLocomotive && (Car as MSTSWagon).BrakeValve == MSTSWagon.BrakeValveType.DistributingValve)
+            {
+                // For distributing valves, we use AutoCylPressurePSI as "Application Chamber/Pipe" pressure
+                // CylPressurePSI is the actual pressure applied to cylinders
+                var loco = Car as MSTSLocomotive;
+                var engineBrakeStatus = loco.EngineBrakeController.Notches[loco.EngineBrakeController.CurrentNotch].Type;
+                var trainBrakeStatus = loco.TrainBrakeController.Notches[loco.TrainBrakeController.CurrentNotch].Type;
+                 // BailOff
+                if (engineBrakeStatus == ControllerState.BailOff)
+                {
+                    AutoCylPressurePSI -= MaxReleaseRatePSIpS * elapsedClockSeconds;
+                    if (AutoCylPressurePSI < 0) AutoCylPressurePSI = 0;
+                }
+                // Emergency application
+                if (trainBrakeStatus == ControllerState.Emergency)
+                {
+                    float dp = elapsedClockSeconds * MaxApplicationRatePSIpS;
+                    if (dp > MaxCylPressurePSI - AutoCylPressurePSI)
+                        dp = MaxCylPressurePSI - AutoCylPressurePSI;
+                    AutoCylPressurePSI += dp;
+                }
+                // Release pipe open
+                HoldingValve = engineBrakeStatus == ControllerState.Release && trainBrakeStatus == ControllerState.Release ? ValveState.Release : ValveState.Lap;
+                
+                // Independent air brake equalization
+                if (AutoCylPressurePSI < loco.Train.BrakeLine3PressurePSI)
+                    AutoCylPressurePSI = loco.Train.BrakeLine3PressurePSI;
+                else
+                    loco.Train.BrakeLine3PressurePSI = AutoCylPressurePSI;
 
-            if (Car is MSTSLocomotive loco && loco.EngineType != TrainCar.EngineTypes.Control)  // TODO - Control cars ned to be linked to power suppy requirements.
+                // Equalization between application chamber and brake cylinders
+                // TODO: Drain air from main reservoir
+                CylPressurePSI = AutoCylPressurePSI;
+            }
+            else
             {
-                //    if (Car is MSTSLocomotive loco && loco.LocomotivePowerSupply.MainPowerSupplyOn)
-                if (loco.LocomotivePowerSupply.MainPowerSupplyOn)
+                bool bailoff = false;
+
+                if (Car is MSTSLocomotive loco && loco.EngineType != TrainCar.EngineTypes.Control)  // TODO - Control cars ned to be linked to power suppy requirements.
                 {
-                    if (loco.Train.LeadLocomotiveIndex >= 0 && ((MSTSLocomotive)loco.Train.Cars[loco.Train.LeadLocomotiveIndex]).BailOff)
-                    {
-                        bailoff = true;
-                        CylPressurePSI -= MaxReleaseRatePSIpS * elapsedClockSeconds;
-                        if (CylPressurePSI < 0) CylPressurePSI = 0;
-                    }
-                    else if (loco.DynamicBrakeAutoBailOff && loco.DynamicBrakePercent > 0 && Car.MaxBrakeForceN > 0)
+                    //    if (Car is MSTSLocomotive loco && loco.LocomotivePowerSupply.MainPowerSupplyOn)
+                    if (loco.LocomotivePowerSupply.MainPowerSupplyOn)
                     {
-                        bailoff = true;
-                        var requiredBrakeForce = Math.Min(AutoCylPressurePSI / MaxCylPressurePSI, 1) * Car.MaxBrakeForceN;
-                        var airBrakeForce = requiredBrakeForce - loco.DynamicBrakeForceN;
-                        var requiredCylPressure = Math.Max(Math.Min(airBrakeForce / Car.MaxBrakeForceN * MaxCylPressurePSI, AutoCylPressurePSI), 0);
-                        if (requiredCylPressure > CylPressurePSI)
-                            CylPressurePSI = Math.Min(requiredCylPressure, CylPressurePSI + MaxApplicationRatePSIpS * elapsedClockSeconds);
-                        if (requiredCylPressure < CylPressurePSI)
-                            CylPressurePSI = Math.Max(requiredCylPressure, CylPressurePSI - MaxReleaseRatePSIpS * elapsedClockSeconds);
+                        if (loco.Train.LeadLocomotiveIndex >= 0 && ((MSTSLocomotive)loco.Train.Cars[loco.Train.LeadLocomotiveIndex]).BailOff)
+                        {
+                            bailoff = true;
+                            CylPressurePSI -= MaxReleaseRatePSIpS * elapsedClockSeconds;
+                            if (CylPressurePSI < 0) CylPressurePSI = 0;
+                        }
+                        else if (loco.DynamicBrakeAutoBailOff && loco.DynamicBrakePercent > 0 && Car.MaxBrakeForceN > 0)
+                        {
+                            bailoff = true;
+                            var requiredBrakeForce = Math.Min(AutoCylPressurePSI / MaxCylPressurePSI, 1) * Car.MaxBrakeForceN;
+                            var airBrakeForce = requiredBrakeForce - loco.DynamicBrakeForceN;
+                            var requiredCylPressure = Math.Max(Math.Min(airBrakeForce / Car.MaxBrakeForceN * MaxCylPressurePSI, AutoCylPressurePSI), 0);
+                            if (requiredCylPressure > CylPressurePSI)
+                                CylPressurePSI = Math.Min(requiredCylPressure, CylPressurePSI + MaxApplicationRatePSIpS * elapsedClockSeconds);
+                            if (requiredCylPressure < CylPressurePSI)
+                                CylPressurePSI = Math.Max(requiredCylPressure, CylPressurePSI - MaxReleaseRatePSIpS * elapsedClockSeconds);
+                        }
                     }
                 }
+                if (!bailoff)
+                    CylPressurePSI = AutoCylPressurePSI;
+                if (CylPressurePSI < BrakeLine3PressurePSI) // Brake Cylinder pressure will be the greater of engine brake pressure or train brake pressure
+                    CylPressurePSI = BrakeLine3PressurePSI;
             }
-            if (!bailoff)
-                CylPressurePSI = AutoCylPressurePSI;
-            if (CylPressurePSI < BrakeLine3PressurePSI) // Brake Cylinder pressure will be the greater of engine brake pressure or train brake pressure
-                CylPressurePSI = BrakeLine3PressurePSI;
 
             // During braking wheelslide control is effected throughout the train by additional equipment on each vehicle. In the piping to each pair of brake cylinders are fitted electrically operated 
             // dump valves. When axle rotations which are sensed electrically, differ by a predetermined speed the dump valves are operated releasing brake cylinder pressure to both axles of the affected 

Source/Orts.Simulation/Simulation/RollingStocks/SubSystems/Controllers/MSTSBrakeController.cs

@@ -128,6 +128,7 @@ public override void UpdatePressure(ref float pressureBar, float elapsedClockSec
                     switch (type)
                     {
                         case ControllerState.Release:
+                        case ControllerState.HoldEngine:
                             IncreasePressure(ref pressureBar, Math.Min(MaxPressureBar(), MainReservoirPressureBar()), ReleaseRateBarpS(), elapsedClockSeconds);
                             DecreasePressure(ref pressureBar, MaxPressureBar(), OverchargeEliminationRateBarpS(), elapsedClockSeconds);
                             epState = 0;
@@ -256,14 +257,15 @@ public override void UpdateEngineBrakePressure(ref float pressureBar, float elap
                     case ControllerState.Lap:
                         break;
                     case ControllerState.FullQuickRelease:
+                    case ControllerState.BailOff:
                         pressureBar -= x * QuickReleaseRateBarpS() * elapsedClockSeconds;
                         break;
                     case ControllerState.Release:
                         pressureBar -= x * ReleaseRateBarpS() * elapsedClockSeconds;
                         break;
                     case ControllerState.Apply:
                     case ControllerState.FullServ:
-                        IncreasePressure(ref pressureBar, x * (MaxPressureBar() - FullServReductionBar()), ApplyRateBarpS(), elapsedClockSeconds);
+                        IncreasePressure(ref pressureBar, MaxPressureBar() - FullServReductionBar(), x*ApplyRateBarpS(), elapsedClockSeconds);
                         break;
                     case ControllerState.ManualBraking:
                     case ControllerState.VacContServ:

Source/Orts.Simulation/Simulation/RollingStocks/SubSystems/Controllers/MSTSNotchController.cs

@@ -79,6 +79,8 @@ public MSTSNotch(float v, int s, string type, STFReader stf)
                 case "brakenotchstart": Type = ControllerState.BrakeNotch; break;
                 case "overchargestart": Type = ControllerState.Overcharge; break;
                 case "slowservicestart": Type = ControllerState.SlowService; break;
+                case "holdenginestart": Type = ControllerState.HoldEngine; break;
+                case "bailoffstart": Type = ControllerState.BailOff; break;
                 default:
                     STFException.TraceInformation(stf, "Skipped unknown notch type " + type);
                     break;