Make PSG Atlas-friendly

MechJeb2/MechJebModuleStageStats.cs

@@ -1,4 +1,4 @@
-extern alias JetBrainsAnnotations;
+extern alias JetBrainsAnnotations;
 using System;
 using System.Collections.Generic;
 using System.Diagnostics;
@@ -21,6 +21,10 @@ public class MechJebModuleStageStats : ComputerModule
         public double AltSLT = 0;
         public double Mach = 0;
 
+        public int HalfStageIndex => _vesselManagerVac.HalfStageIndex;
+        [Persistent(pass = (int)(Pass.TYPE | Pass.GLOBAL))]
+        public readonly EditableDoubleMult HalfStageEndMass = new EditableDoubleMult(0, 0.001);
+
         private int _vabRebuildTimer = 1;
 
         public readonly List<FuelStats> AtmoStats = new List<FuelStats>();
@@ -148,6 +152,7 @@ private void RunSimulation()
                 _vesselManagerVac.SetConditions(0, 0, 0);
                 _vesselManagerVac.SetInitial(VesselState.Time, VesselState.OrbitalPosition.WorldToV3Rotated(),
                     VesselState.OrbitalVelocity.WorldToV3Rotated(), VesselState.Forward.WorldToV3Rotated());
+                _vesselManagerVac.SetupStageAndAHalf(HalfStageEndMass);
                 if (!_vesselManagerVac.TryStartFuelFlowSimulationJob())
                     throw new Exception("[MechJebModuleStageStats] could not start vac stats job");
             }
@@ -158,7 +163,7 @@ private void RunSimulation()
                 _vesselManagerAtmo.SetConditions(atmDensity, staticPressureKpa * PhysicsGlobals.KpaToAtmospheres, mach);
                 _vesselManagerAtmo.SetInitial(VesselState.Time, VesselState.OrbitalPosition.WorldToV3Rotated(),
                     VesselState.OrbitalVelocity.WorldToV3Rotated(), VesselState.Forward.WorldToV3Rotated());
-                //_vesselManagerAtmo.PrintVessel();
+                _vesselManagerAtmo.SetupStageAndAHalf(HalfStageEndMass);
                 if (!_vesselManagerAtmo.TryStartFuelFlowSimulationJob())
                     throw new Exception("[MechJebModuleStageStats] could not start atmo stats job");
             }

MechJeb2/MechJebModuleStagingController.cs

@@ -300,6 +300,12 @@ public override void OnFixedUpdate()
             UpdateBurnedResources();
             _shouldDropSolids = null; // invalidate the cache; _droppingSolids recomputes lazily if needed this update
 
+            if (Vessel.currentStage == _stats.HalfStageIndex && Vessel.totalMass <= _stats.HalfStageEndMass)
+            {
+                Stage();
+                return;
+            }
+
             // don't decouple active or idle engines or tanks
             if (InverseStageDecouplesActiveOrIdleEngineOrTank(Vessel.currentStage - 1, _burnedResources, _activeModuleEngines) &&
                 !InverseStageReleasesClamps(Vessel.currentStage - 1))
@@ -613,7 +619,7 @@ private bool HasActiveOrIdleEngineOrTankDescendant(Part p, List<int> tankResourc
                         PartResource r = p.Resources.Get(propellant.id);
 
                         if (r.amount <= p.resourceRequestRemainingThreshold)
-                            continue;
+                            return false;
                         if (r.info.id == PartResourceLibrary.ElectricityHashcode)
                             continue;
                         if (!tankResources.Contains(r.info.id))

MechJeb2/MechJebStageStatsHelper.cs

@@ -344,6 +344,15 @@ public void AllStageStats()
 
             Profiler.EndSample();
 
+            if (stats.HalfStageIndex != -1)
+            {
+                GUILayout.BeginHorizontal();
+                GUILayout.Label($"Half-stage index: {stats.HalfStageIndex}", GUILayout.Width(130));
+                GUILayout.Space(30);
+                GuiUtils.SimpleTextBox("End mass: ", stats.HalfStageEndMass, "kg");
+                GUILayout.EndHorizontal();
+            }
+
             Profiler.BeginSample("AllStageStats.DrawColumns");
 
             GUILayout.BeginHorizontal();

MechJebLib/FuelFlowSimulation/FuelFlowSimulation.cs

@@ -1,10 +1,11 @@
-/*
+/*
  * Copyright Lamont Granquist, Sebastien Gaggini and the MechJeb contributors
  * SPDX-License-Identifier: LicenseRef-PD-hp OR Unlicense OR CC0-1.0 OR 0BSD OR MIT-0 OR MIT OR LGPL-2.1+
  */
 
 using System;
 using System.Collections.Generic;
+using System.Linq;
 using System.Runtime.CompilerServices;
 using MechJebLib.FuelFlowSimulation.PartModules;
 using MechJebLib.Utils;
@@ -25,6 +26,7 @@ public class FuelFlowSimulation : AsyncJob
         private readonly HashSet<SimPart> _partsWithRCSDrains = new HashSet<SimPart>();
         private readonly HashSet<SimPart> _partsWithRCSDrains2 = new HashSet<SimPart>();
         private bool _allocatedFirstSegment;
+        private bool _halfStageIsDetected;
 
         public override void Run(object? o = null)
         {
@@ -34,6 +36,7 @@ public override void Run(object? o = null)
             if (!(o is SimVessel vessel))
                 throw new ArgumentException("o is not a SimVessel", nameof(o));
 
+            _halfStageIsDetected = false;
             _allocatedFirstSegment = false;
             _time = 0;
             Segments.Clear();
@@ -53,6 +56,9 @@ public override void Run(object? o = null)
             Segments.Reverse();
 
             _partsWithResourceDrains.Clear();
+
+            if (!_halfStageIsDetected)
+                vessel.HalfStageIndex = -1;
         }
 
         private void SimulateRCS(SimVessel vessel, bool max)
@@ -129,24 +135,49 @@ private void SimulateStage(SimVessel vessel)
             ComputeRcsUllageTime(vessel);
 
             UpdateResourceDrainsAndResiduals(vessel);
-            double currentThrust = vessel.ThrustMagnitude;
+            int activeAngines = vessel.ActiveEngines.Count;
+
+            if (!_halfStageIsDetected //is anyone insane enough to build a rocket with multiple half-stages? You never know
+                && vessel.ActiveEngines.Count > 0
+                && _partsWithResourceDrains.Count > 0)
+            {
+                int earliestDroppedEgineInStage = 0, earliestDroppedTankInStage = 0;
+                for (int i = 0; i < vessel.ActiveEngines.Count; i++)
+                {
+                    earliestDroppedEgineInStage = Max(earliestDroppedEgineInStage, vessel.ActiveEngines[i].Part.DecoupledInStage);
+                }
+
+                foreach (var tank in _partsWithResourceDrains)
+                {
+                    earliestDroppedTankInStage = Max(earliestDroppedTankInStage, tank.DecoupledInStage);
+                }
+
+                if (earliestDroppedEgineInStage > earliestDroppedTankInStage)
+                {
+                    _halfStageIsDetected = true;
+                    vessel.HalfStageIndex = earliestDroppedEgineInStage + 1;
+                }
+            }
 
             for (int steps = MAXSTEPS; steps > 0; steps--)
             {
                 if (AllowedToStage(vessel))
                     return;
 
                 double dt = MinimumTimeStep();
+                if (_currentSegment.KSPStage == vessel.HalfStageIndex)
+                {
+                    double massFlow = ResourceMaxMassFlow(vessel);
+                    dt = Min(dt, (vessel.Mass - vessel.HalfStageEndMass) / massFlow);
+                }
 
-                // FIXME: if we have constructed a segment which is > 0 dV, but less than 0.02s, and there's a
-                // prior > 0dV segment in the same kspStage we should add those together to reduce clutter.
-                if (Abs(vessel.ThrustMagnitude - currentThrust) > 1e-12)
+                if (dt >= 0.02 && activeAngines != vessel.ActiveEngines.Count)
                 {
                     ClearResiduals();
                     ComputeRcsMaxValues(vessel);
                     FinishSegment(vessel);
                     GetNextSegment(vessel);
-                    currentThrust = vessel.ThrustMagnitude;
+                    activeAngines = vessel.ActiveEngines.Count;
                 }
 
                 _time += dt;
@@ -388,7 +419,7 @@ private double MinimumTimeStep()
         {
             double maxTime = ResourceMaxTime();
 
-            return maxTime < double.MaxValue && maxTime >= 0 ? maxTime : 0;
+            return maxTime < double.MaxValue && maxTime > 0.001 ? maxTime : 0.001;
         }
 
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
@@ -402,6 +433,17 @@ private double ResourceMaxTime()
             return maxTime;
         }
 
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        private double ResourceMaxMassFlow(SimVessel vessel)
+        {
+            double massFlow = 0;
+
+            foreach (SimModuleEngines engine in vessel.ActiveEngines)
+                massFlow += engine.MassFlowRate;
+
+            return massFlow;
+        }
+
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
         private void FinishRcsSegment(bool max, double deltaTime, double startMass, double endMass, double rcsThrust)
         {
@@ -488,6 +530,9 @@ private static bool AllowedToStage(SimVessel vessel)
             if (vessel.ActiveEngines.Count == 0)
                 return true;
 
+            if (vessel.CurrentStage == vessel.HalfStageIndex && vessel.Mass - vessel.HalfStageEndMass < 1e-6)
+                return true;
+
             for (int i = 0; i < vessel.ActiveEngines.Count; i++)
             {
                 SimModuleEngines e = vessel.ActiveEngines[i];

MechJebLib/FuelFlowSimulation/SimResource.cs

@@ -1,4 +1,4 @@
-/*
+/*
  * Copyright Lamont Granquist, Sebastien Gaggini and the MechJeb contributors
  * SPDX-License-Identifier: LicenseRef-PD-hp OR Unlicense OR CC0-1.0 OR 0BSD OR MIT-0 OR MIT OR LGPL-2.1+
  */
@@ -27,8 +27,8 @@ public double Amount
         public SimResource Drain(double resourceDrain)
         {
             _amount -= resourceDrain;
-            if (_amount < 0)
-                _amount = 0;
+            if (_amount < ResidualThreshold)
+                _amount = ResidualThreshold;
 
             return this;
         }

MechJebLib/FuelFlowSimulation/SimVessel.cs

@@ -1,4 +1,4 @@
-/*
+/*
  * Copyright Lamont Granquist, Sebastien Gaggini and the MechJeb contributors
  * SPDX-License-Identifier: LicenseRef-PD-hp OR Unlicense OR CC0-1.0 OR 0BSD OR MIT-0 OR MIT OR LGPL-2.1+
  */
@@ -49,6 +49,9 @@ public class SimVessel : IDisposable
         public double T;
         public V3 R, V, U;
 
+        public int HalfStageIndex = -1;
+        public double HalfStageEndMass = 0;
+
         // CurrentStage gets scribbled over by the FuelFlowSimulation, SetCurrentStage() is intended to be used in
         // the VesselBuilder and DecouplingAnalyzer to figure out the right value, ResetCurrentStage() is called by
         // the VesselUpdater to reset it back.
@@ -83,6 +86,15 @@ public void SetInitial(double t, V3 r, V3 v, V3 u)
             U = u;
         }
 
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public void SetupStageAndAHalf(double endMass)
+        {
+            if (HalfStageIndex != -1)
+            {
+                HalfStageEndMass = endMass;
+            }
+        }
+
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
         public void UpdateMass()
         {

MechJebLibBindings/FuelFlowSimulation/SimVesselBuilder.cs

@@ -1,4 +1,4 @@
-/*
+/*
  * Copyright Lamont Granquist, Sebastien Gaggini and the MechJeb contributors
  * SPDX-License-Identifier: LicenseRef-PD-hp OR Unlicense OR CC0-1.0 OR 0BSD OR MIT-0 OR MIT OR LGPL-2.1+
  */
@@ -36,17 +36,9 @@ public class SimVesselBuilder
 
             private static readonly CrewMass _crewMassDelegate;
 
-            private SimVessel _vessel
-            {
-                get => _manager._vessel;
-                set => _manager._vessel = value;
-            }
+            private SimVessel _vessel => _manager._vessel;
 
-            private IShipconstruct _kspVessel
-            {
-                get => _manager._kspVessel;
-                set => _manager._kspVessel = value;
-            }
+            private IShipconstruct _kspVessel => _manager._kspVessel;
 
             private readonly SimVesselManager _manager;
 
@@ -63,7 +55,7 @@ static SimVesselBuilder()
 
             private static double CrewMassNew(ProtoCrewMember crew) => PhysicsGlobals.KerbalCrewMass + crew.ResourceMass() + crew.InventoryMass();
 
-            public SimVesselBuilder(SimVesselManager manager)
+            internal SimVesselBuilder(SimVesselManager manager)
             {
                 _manager = manager;
             }
@@ -121,14 +113,12 @@ internal void UpdateSymmetryParts()
                 }
             }
 
-            internal void BuildVessel(IShipconstruct kspVessel)
+            internal void BuildVessel()
             {
-                _vessel.Dispose();
-                _vessel = SimVessel.Borrow();
-                _kspVessel = kspVessel;
+                BuildParts();
             }
 
-            internal void BuildParts()
+            private void BuildParts()
             {
                 _vessel.SetCurrentStage(StageManager.CurrentStage);
 

MechJebLibBindings/FuelFlowSimulation/SimVesselManager.cs

@@ -1,4 +1,4 @@
-/*
+/*
  * Copyright Lamont Granquist, Sebastien Gaggini and the MechJeb contributors
  * SPDX-License-Identifier: LicenseRef-PD-hp OR Unlicense OR CC0-1.0 OR 0BSD OR MIT-0 OR MIT OR LGPL-2.1+
  */
@@ -32,6 +32,8 @@ public partial class SimVesselManager
         public V3     V => _vessel.V;
         public V3     U => _vessel.U;
 
+        public int HalfStageIndex => _vessel.HalfStageIndex;
+
         public SimVesselManager()
         {
             _builder = new SimVesselBuilder(this);
@@ -42,9 +44,12 @@ public SimVesselManager()
 
         public void Build(IShipconstruct vessel)
         {
+            _vessel.Dispose();
+            _vessel = SimVessel.Borrow();
+            _kspVessel = vessel;
+
             Clear();
-            _builder.BuildVessel(vessel);
-            _builder.BuildParts();
+            _builder.BuildVessel();
             Update();
             _builder.UpdateLinks();
             _builder.UpdateCrossFeedSet();
@@ -62,6 +67,8 @@ public void SetConditions(double atmDensity, double atmPressure, double machNumb
 
         public void SetInitial(double t, V3 r, V3 v, V3 u) => _vessel.SetInitial(t, r, v, u);
 
+        public void SetupStageAndAHalf(double endMass) => _vessel.SetupStageAndAHalf(endMass);
+
         public bool TryStartFuelFlowSimulationJob()
         {
             FuelFlowSimulation.DVLinearThrust = DVLinearThrust;

MechJebLibBindings/FuelFlowSimulation/SimVesselUpdater.cs

@@ -1,4 +1,4 @@
-/*
+/*
  * Copyright Lamont Granquist, Sebastien Gaggini and the MechJeb contributors
  * SPDX-License-Identifier: LicenseRef-PD-hp OR Unlicense OR CC0-1.0 OR 0BSD OR MIT-0 OR MIT OR LGPL-2.1+
  */
@@ -38,7 +38,7 @@ static SimVesselUpdater()
                 _isRealFuelsLoadedCorrectly = IsLoadedRealFuels && _rfPredictedMaximumResiduals.IsValid;
             }
 
-            public SimVesselUpdater(SimVesselManager manager)
+            internal SimVesselUpdater(SimVesselManager manager)
             {
                 _manager = manager;
             }