// Copyright Epic Games, Inc. All Rights Reserved. #include "StateTreeExecutionContext.h" #include "StateTree.h" #include "StateTreeTaskBase.h" #include "StateTreeEvaluatorBase.h" #include "StateTreeConditionBase.h" #include "CoreMinimal.h" #include "Engine/World.h" #include "VisualLogger/VisualLogger.h" #include "ProfilingDebugging/CsvProfiler.h" #include "Algo/Reverse.h" #include "Logging/LogScopedVerbosityOverride.h" #define STATETREE_LOG(Verbosity, Format, ...) UE_VLOG_UELOG(GetOwner(), LogStateTree, Verbosity, TEXT("%s: ") Format, *GetInstanceDescription(), ##__VA_ARGS__) #define STATETREE_CLOG(Condition, Verbosity, Format, ...) UE_CVLOG_UELOG((Condition), GetOwner(), LogStateTree, Verbosity, TEXT("%s: ") Format, *GetInstanceDescription(), ##__VA_ARGS__) namespace UE::StateTree { constexpr int32 DebugIndentSize = 2; } FStateTreeExecutionContext::FStateTreeExecutionContext() { } FStateTreeExecutionContext::~FStateTreeExecutionContext() { } bool FStateTreeExecutionContext::Init(UObject& InOwner, const UStateTree& InStateTree, const EStateTreeStorage InStorageType) { // Set owner first for proper logging (it will be reset in case of failure) Owner = &InOwner; if (!InStateTree.IsValidStateTree()) { STATETREE_LOG(Error, TEXT("%s: StateTree asset '%s' is not valid."), ANSI_TO_TCHAR(__FUNCTION__), *InStateTree.GetName()); Reset(); return false; } StateTree = &InStateTree; StorageType = InStorageType; if (StorageType == EStateTreeStorage::Internal) { // Duplicate instance state. StorageInstance = StateTree->InstanceStorageDefaultValue; InitInstanceData(InOwner, FStateTreeDataView(StorageInstance)); } // Initialize data views for all possible items. DataViews.SetNum(StateTree->GetNumDataViews()); // Initialize array to keep track of which states have been updated. VisitedStates.Init(false, StateTree->States.Num()); return true; } bool FStateTreeExecutionContext::InitInstanceData(UObject& InOwner, FStateTreeDataView ExternalStorage) const { if (!Owner || !StateTree) { STATETREE_LOG(Error, TEXT("%s: Failed to init instance data on '%s' using StateTree '%s'."), ANSI_TO_TCHAR(__FUNCTION__), *GetNameSafe(Owner), *GetNameSafe(StateTree)); return false; } check (ExternalStorage.IsValid()); FStateTreeExecutionState& Exec = GetExecState(ExternalStorage); Exec.InstanceObjects.Reset(); for (const UObject* Instance : StateTree->InstanceObjects) { Exec.InstanceObjects.Add(DuplicateObject(Instance, &InOwner)); } return true; } EStateTreeRunStatus FStateTreeExecutionContext::Start(FStateTreeDataView ExternalStorage) { if (!Owner || !StateTree) { return EStateTreeRunStatus::Failed; } FStateTreeDataView Storage = SelectMutableStorage(ExternalStorage); FStateTreeExecutionState& Exec = GetExecState(Storage); // Stop if still running previous state. if (Exec.TreeRunStatus == EStateTreeRunStatus::Running) { const FStateTreeTransitionResult Transition(FStateTreeStateStatus(Exec.CurrentState, Exec.LastTickStatus), FStateTreeHandle::Succeeded); ExitState(Storage, Transition); } // Initialize to unset running state. Exec.TreeRunStatus = EStateTreeRunStatus::Running; Exec.CurrentState = FStateTreeHandle::Invalid; Exec.LastTickStatus = EStateTreeRunStatus::Unset; // Select new Starting from root. VisitedStates.Init(false, StateTree->States.Num()); static const FStateTreeHandle RootState = FStateTreeHandle(0); const FStateTreeTransitionResult Transition = SelectState(Storage, FStateTreeStateStatus(FStateTreeHandle::Invalid), RootState, RootState, 0); // Handle potential transition. if (Transition.Next.IsValid()) { if (Transition.Next == FStateTreeHandle::Succeeded || Transition.Next == FStateTreeHandle::Failed) { // Transition to a terminal state (succeeded/failed), or default transition failed. STATETREE_LOG(Warning, TEXT("%s: Tree %s at StateTree start on '%s' using StateTree '%s'."), ANSI_TO_TCHAR(__FUNCTION__), Transition.Next == FStateTreeHandle::Succeeded ? TEXT("succeeded") : TEXT("failed"), *GetNameSafe(Owner), *GetNameSafe(StateTree)); Exec.TreeRunStatus = Transition.Next == FStateTreeHandle::Succeeded ? EStateTreeRunStatus::Succeeded : EStateTreeRunStatus::Failed; } else { // Enter state tasks can fail/succeed, treat it same as tick. Exec.LastTickStatus = EnterState(Storage, Transition); Exec.CurrentState = Transition.Next; // Report state completed immediately. if (Exec.LastTickStatus != EStateTreeRunStatus::Running) { StateCompleted(Storage, Exec.CurrentState, Exec.LastTickStatus); } } } if (!Exec.CurrentState.IsValid()) { // Should not happen. This may happen if initial state could not be selected. STATETREE_LOG(Error, TEXT("%s: Failed to select initial state on '%s' using StateTree '%s'. This should not happen, check that the StateTree logic can always select a state at start."), ANSI_TO_TCHAR(__FUNCTION__), *GetNameSafe(Owner), *GetNameSafe(StateTree)); Exec.TreeRunStatus = EStateTreeRunStatus::Failed; } return Exec.TreeRunStatus; } EStateTreeRunStatus FStateTreeExecutionContext::Stop(FStateTreeDataView ExternalStorage) { if (!Owner || !StateTree) { return EStateTreeRunStatus::Failed; } FStateTreeDataView Storage = SelectMutableStorage(ExternalStorage); FStateTreeExecutionState& Exec = GetExecState(Storage); // Stop if still running. if (Exec.TreeRunStatus == EStateTreeRunStatus::Running) { const FStateTreeTransitionResult Transition(FStateTreeStateStatus(Exec.CurrentState, Exec.LastTickStatus), FStateTreeHandle::Succeeded); ExitState(Storage, Transition); } Exec.TreeRunStatus = EStateTreeRunStatus::Succeeded; Exec.CurrentState = FStateTreeHandle::Succeeded; Exec.LastTickStatus = EStateTreeRunStatus::Unset; return Exec.TreeRunStatus; } EStateTreeRunStatus FStateTreeExecutionContext::Tick(const float DeltaTime, FStateTreeDataView ExternalStorage) { CSV_SCOPED_TIMING_STAT_EXCLUSIVE(StateTreeCtxTick); if (!Owner || !StateTree) { return EStateTreeRunStatus::Failed; } FStateTreeDataView Storage = SelectMutableStorage(ExternalStorage); FStateTreeExecutionState& Exec = GetExecState(Storage); // No ticking of the tree is done or stopped. if (Exec.TreeRunStatus != EStateTreeRunStatus::Running) { return Exec.TreeRunStatus; } // Update the gated transition time. if (Exec.GatedTransitionIndex != INDEX_NONE) { Exec.GatedTransitionTime -= DeltaTime; } // Reset visited state, used to keep track which state's evaluators have been ticked. VisitedStates.Init(false, StateTree->States.Num()); if (Exec.LastTickStatus == EStateTreeRunStatus::Running) { // Tick evaluators on active states. Further evaluator may be ticked during selection as non-active states are visited. // Ticked states are kept track of and evaluators are ticked just once per frame. TickEvaluators(Storage, Exec.CurrentState, EStateTreeEvaluationType::Tick, DeltaTime); // Tick tasks on active states. Exec.LastTickStatus = TickTasks(Storage, Exec.CurrentState, DeltaTime); // Report state completed immediately. if (Exec.LastTickStatus != EStateTreeRunStatus::Running) { StateCompleted(Storage, Exec.CurrentState, Exec.LastTickStatus); } } // The state selection is repeated up to MaxIteration time. This allows failed EnterState() to potentially find a new state immediately. // This helps event driven StateTrees to not require another event/tick to find a suitable state. static const int32 MaxIterations = 5; for (int32 Iter = 0; Iter < MaxIterations; Iter++) { // Trigger conditional transitions or state succeed/failed transitions. First tick transition is handled here too. FStateTreeTransitionResult Transition = TriggerTransitions(Storage, FStateTreeStateStatus(Exec.CurrentState, Exec.LastTickStatus), 0); // Handle potential transition. if (Transition.Next.IsValid()) { ExitState(Storage, Transition); if (Transition.Next == FStateTreeHandle::Succeeded || Transition.Next == FStateTreeHandle::Failed) { // Transition to a terminal state (succeeded/failed), or default transition failed. Exec.TreeRunStatus = Transition.Next == FStateTreeHandle::Succeeded ? EStateTreeRunStatus::Succeeded : EStateTreeRunStatus::Failed; return Exec.TreeRunStatus; } // Enter state tasks can fail/succeed, treat it same as tick. Exec.LastTickStatus = EnterState(Storage, Transition); Exec.CurrentState = Transition.Next; // Report state completed immediately. if (Exec.LastTickStatus != EStateTreeRunStatus::Running) { StateCompleted(Storage, Exec.CurrentState, Exec.LastTickStatus); } } // Stop as soon as have found a running state. if (Exec.LastTickStatus == EStateTreeRunStatus::Running) { break; } } if (!Exec.CurrentState.IsValid()) { // Should not happen. This may happen if a state completion transition could not be selected. STATETREE_LOG(Error, TEXT("%s: Failed to select state on '%s' using StateTree '%s'. This should not happen, state completion transition is likely missing."), ANSI_TO_TCHAR(__FUNCTION__), *GetNameSafe(Owner), *GetNameSafe(StateTree)); Exec.TreeRunStatus = EStateTreeRunStatus::Failed; return Exec.TreeRunStatus; } return Exec.TreeRunStatus; } void FStateTreeExecutionContext::Reset() { StateTree = nullptr; Owner = nullptr; DataViews.Reset(); StorageInstance.Reset(); StorageType = EStateTreeStorage::Internal; VisitedStates.Reset(); } EStateTreeRunStatus FStateTreeExecutionContext::EnterState(FStateTreeDataView Storage, const FStateTreeTransitionResult& Transition) { if (!Transition.Next.IsValid()) { return EStateTreeRunStatus::Failed; } // Activate evaluators along the active branch. TStaticArray States; const int32 NumStates = GetActiveStates(Transition.Next, States); TStaticArray PrevStates; const int32 NumPrevStates = GetActiveStates(Transition.Source.State, PrevStates); // Pad prev states with invalid states if it's shorter. for (int32 Index = NumPrevStates; Index < NumStates; Index++) { PrevStates[Index] = FStateTreeHandle::Invalid; } // On target branch means that the state is the target of current transition or child of it. // States which were active before and will remain active, but are not on target branch will not get // EnterState called. That is, a transition is handled as "replan from this state". bool bOnTargetBranch = false; FStateTreeTransitionResult CurrentTransition = Transition; EStateTreeRunStatus Result = EStateTreeRunStatus::Running; EnterStateStatus = Result; for (int32 Index = 0; Index < NumStates; Index++) { const FStateTreeHandle CurrentHandle = States[Index]; const FBakedStateTreeState& State = StateTree->States[CurrentHandle.Index]; bOnTargetBranch = bOnTargetBranch || CurrentHandle == Transition.Target; const bool bWasActive = PrevStates[Index] == CurrentHandle; if (bWasActive && !bOnTargetBranch) { // States which will keep on begin active and were not part of the transition will not get enter/exit state. // Must update data views. for (int32 EvalIndex = 0; EvalIndex < int32(State.EvaluatorsNum); EvalIndex++) { const FStateTreeEvaluatorBase& Eval = GetItem(int32(State.EvaluatorsBegin) + EvalIndex); DataViews[Eval.DataViewIndex] = GetInstanceData(Storage, Eval.bInstanceIsObject, Eval.InstanceIndex); } for (int32 TaskIndex = 0; TaskIndex < int32(State.TasksNum); TaskIndex++) { const FStateTreeTaskBase& Task = GetItem(int32(State.TasksBegin) + TaskIndex); DataViews[Task.DataViewIndex] = GetInstanceData(Storage, Task.bInstanceIsObject, Task.InstanceIndex); } continue; } CurrentTransition.Current = CurrentHandle; const EStateTreeStateChangeType ChangeType = bWasActive ? EStateTreeStateChangeType::Sustained : EStateTreeStateChangeType::Changed; STATETREE_LOG(Log, TEXT("%*sEnter state '%s' %s"), Index*UE::StateTree::DebugIndentSize, TEXT(""), *DebugGetStatePath(States, Index), *StaticEnum()->GetValueAsString(ChangeType)); for (int32 EvalIndex = 0; EvalIndex < int32(State.EvaluatorsNum); EvalIndex++) { const FStateTreeEvaluatorBase& Eval = GetItem(int32(State.EvaluatorsBegin) + EvalIndex); const FStateTreeDataView EvalInstanceView = GetInstanceData(Storage, Eval.bInstanceIsObject, Eval.InstanceIndex); DataViews[Eval.DataViewIndex] = EvalInstanceView; // Copy bound properties. if (Eval.BindingsBatch.IsValid()) { StateTree->PropertyBindings.CopyTo(DataViews, Eval.BindingsBatch.Index, EvalInstanceView); } STATETREE_LOG(Verbose, TEXT("%*s Notify Evaluator '%s'."), Index*UE::StateTree::DebugIndentSize, TEXT(""), *Eval.Name.ToString()); Eval.EnterState(*this, ChangeType, CurrentTransition); } // Activate tasks on current state. for (int32 TaskIndex = 0; TaskIndex < int32(State.TasksNum); TaskIndex++) { const FStateTreeTaskBase& Task = GetItem(int32(State.TasksBegin) + TaskIndex); const FStateTreeDataView TaskInstanceView = GetInstanceData(Storage, Task.bInstanceIsObject, Task.InstanceIndex); DataViews[Task.DataViewIndex] = TaskInstanceView; // Copy bound properties. if (Task.BindingsBatch.IsValid()) { StateTree->PropertyBindings.CopyTo(DataViews, Task.BindingsBatch.Index, TaskInstanceView); } STATETREE_LOG(Verbose, TEXT("%*s Notify Task '%s'"), Index*UE::StateTree::DebugIndentSize, TEXT(""), *Task.Name.ToString()); const EStateTreeRunStatus Status = Task.EnterState(*this, ChangeType, CurrentTransition); if (Status == EStateTreeRunStatus::Failed) { Result = Status; // @todo StateTree: Ideally we should break here, but it is commented out for now in order to keep symmetrical enter/exit calls. // break; // As a workaround, we mark EnterStateStatus as 'failed' in context so remaining calls to EnterState could be aware of the failure and act accordingly. EnterStateStatus = Status; } } } return Result; } void FStateTreeExecutionContext::ExitState(FStateTreeDataView Storage, const FStateTreeTransitionResult& Transition) { if (!Transition.Source.State.IsValid()) { return; } // Reset transition delay FStateTreeExecutionState& Exec = GetExecState(Storage); Exec.GatedTransitionIndex = INDEX_NONE; Exec.GatedTransitionTime = 0.0f; // Deactivate evaluators along the active branch. TStaticArray States; const int32 NumStates = GetActiveStates(Transition.Source.State, States); TStaticArray NextStates; const int32 NumNextStates = GetActiveStates(Transition.Next, NextStates); // Pad next states with invalid states if it's shorter. for (int32 Index = NumNextStates; Index < NumStates; Index++) { NextStates[Index] = FStateTreeHandle::Invalid; } // On target branch means that the state is the target of current transition or child of it. // States which were active before and will remain active, but are not on target branch will not get // EnterState called. That is, a transition is handled as "replan from this state". bool bOnTargetBranch = false; FStateTreeTransitionResult CurrentTransition = Transition; // It would be more symmetrical, if the evals, tasks and states were executed in reverse order, but we need // to do it like this because of the property copies. for (int32 Index = 0; Index < NumStates; Index++) { const FStateTreeHandle CurrentHandle = States[Index]; const FStateTreeHandle NextHandle = NextStates[Index]; const FBakedStateTreeState& State = StateTree->States[CurrentHandle.Index]; const bool bRemainsActive = NextHandle == States[Index]; bOnTargetBranch = bOnTargetBranch || NextHandle == Transition.Target; if (bRemainsActive && !bOnTargetBranch) { // States which will keep on begin active and were not part of the transition will not get enter/exit state. // Must update item views. for (int32 EvalIndex = 0; EvalIndex < int32(State.EvaluatorsNum); EvalIndex++) { FStateTreeEvaluatorBase& Eval = GetItem(int32(State.EvaluatorsBegin) + EvalIndex); DataViews[Eval.DataViewIndex] = GetInstanceData(Storage, Eval.bInstanceIsObject, Eval.InstanceIndex); } for (int32 TaskIndex = 0; TaskIndex < int32(State.TasksNum); TaskIndex++) { FStateTreeTaskBase& Task = GetItem(int32(State.TasksBegin) + TaskIndex); DataViews[Task.DataViewIndex] = GetInstanceData(Storage, Task.bInstanceIsObject, Task.InstanceIndex); } continue; } CurrentTransition.Current = CurrentHandle; const EStateTreeStateChangeType ChangeType = bRemainsActive ? EStateTreeStateChangeType::Sustained : EStateTreeStateChangeType::Changed; STATETREE_LOG(Log, TEXT("%*sExit state '%s' %s"), Index*UE::StateTree::DebugIndentSize, TEXT(""), *DebugGetStatePath(States, Index), *StaticEnum()->GetValueAsString(ChangeType)); for (int32 EvalIndex = 0; EvalIndex < int32(State.EvaluatorsNum); EvalIndex++) { const FStateTreeEvaluatorBase& Eval = GetItem(int32(State.EvaluatorsBegin) + EvalIndex); const FStateTreeDataView EvalInstanceView = GetInstanceData(Storage, Eval.bInstanceIsObject, Eval.InstanceIndex); DataViews[Eval.DataViewIndex] = EvalInstanceView; // Copy bound properties. if (Eval.BindingsBatch.IsValid()) { StateTree->PropertyBindings.CopyTo(DataViews, Eval.BindingsBatch.Index, EvalInstanceView); } STATETREE_LOG(Verbose, TEXT("%*s Notify Evaluator '%s'."), Index*UE::StateTree::DebugIndentSize, TEXT(""), *Eval.Name.ToString()); Eval.ExitState(*this, ChangeType, CurrentTransition); } // Deactivate tasks on current State for (int32 TaskIndex = 0; TaskIndex < int32(State.TasksNum); TaskIndex++) { const FStateTreeTaskBase& Task = GetItem(int32(State.TasksBegin) + TaskIndex); const FStateTreeDataView TaskInstanceView = GetInstanceData(Storage, Task.bInstanceIsObject, Task.InstanceIndex); DataViews[Task.DataViewIndex] = TaskInstanceView; // Copy bound properties. if (Task.BindingsBatch.IsValid()) { StateTree->PropertyBindings.CopyTo(DataViews, Task.BindingsBatch.Index, TaskInstanceView); } STATETREE_LOG(Verbose, TEXT("%*s Notify Task '%s'"), Index*UE::StateTree::DebugIndentSize, TEXT(""), *Task.Name.ToString()); Task.ExitState(*this, ChangeType, CurrentTransition); } } } void FStateTreeExecutionContext::StateCompleted(FStateTreeDataView Storage, const FStateTreeHandle CurrentState, const EStateTreeRunStatus CompletionStatus) { if (!CurrentState.IsValid()) { return; } TStaticArray States; const int32 NumStates = GetActiveStates(CurrentState, States); // Call from child towards root to allow to pass results back. // Note: Completed is assumed to be called immediately after tick or enter state, so there's no property copying. for (int32 Index = NumStates - 1; Index >= 0; Index--) { const FStateTreeHandle CurrentHandle = States[Index]; const FBakedStateTreeState& State = StateTree->States[CurrentHandle.Index]; STATETREE_LOG(Verbose, TEXT("%*sState Completed '%s' %s"), Index*UE::StateTree::DebugIndentSize, TEXT(""), *DebugGetStatePath(States, Index), *StaticEnum()->GetValueAsString(CompletionStatus)); // Notify Tasks for (int32 TaskIndex = int32(State.TasksNum) - 1; TaskIndex >= 0; TaskIndex--) { const FStateTreeTaskBase& Task = GetItem(int32(State.TasksBegin) + TaskIndex); STATETREE_LOG(Verbose, TEXT("%*s Notify Task '%s'"), Index*UE::StateTree::DebugIndentSize, TEXT(""), *Task.Name.ToString()); Task.StateCompleted(*this, CompletionStatus, CurrentState); } // Notify evaluators for (int32 EvalIndex = int32(State.EvaluatorsNum) - 1; EvalIndex >= 0; EvalIndex--) { const FStateTreeEvaluatorBase& Eval = GetItem(int32(State.EvaluatorsBegin) + EvalIndex); STATETREE_LOG(Verbose, TEXT("%*s Notify Evaluator '%s'"), Index*UE::StateTree::DebugIndentSize, TEXT(""), *Eval.Name.ToString()); Eval.StateCompleted(*this, CompletionStatus, CurrentState); } } } void FStateTreeExecutionContext::TickEvaluators(FStateTreeDataView Storage, const FStateTreeHandle CurrentState, const EStateTreeEvaluationType EvalType, const float DeltaTime) { CSV_SCOPED_TIMING_STAT_EXCLUSIVE(StateTreeCtxTickEvaluators); if (!CurrentState.IsValid()) { return; } TStaticArray States; const int32 NumStates = GetActiveStates(CurrentState, States); for (int32 Index = 0; Index < NumStates; Index++) { const FStateTreeHandle CurrentHandle = States[Index]; if (VisitedStates[CurrentHandle.Index]) { // Already ticked this frame. continue; } const FBakedStateTreeState& State = StateTree->States[CurrentHandle.Index]; STATETREE_CLOG(State.EvaluatorsNum > 0, Verbose, TEXT("%*sTicking Evaluators of state '%s' %s"), Index*UE::StateTree::DebugIndentSize, TEXT(""), *DebugGetStatePath(States, Index), *StaticEnum()->GetValueAsString(EvalType)); // Tick evaluators for (int32 EvalIndex = 0; EvalIndex < int32(State.EvaluatorsNum); EvalIndex++) { const FStateTreeEvaluatorBase& Eval = GetItem(int32(State.EvaluatorsBegin) + EvalIndex); const FStateTreeDataView EvalInstanceView = GetInstanceData(Storage, Eval.bInstanceIsObject, Eval.InstanceIndex); DataViews[Eval.DataViewIndex] = EvalInstanceView; // Copy bound properties. if (Eval.BindingsBatch.IsValid()) { StateTree->PropertyBindings.CopyTo(DataViews, Eval.BindingsBatch.Index, EvalInstanceView); } STATETREE_LOG(Verbose, TEXT("%*s Evaluate: '%s'"), Index*UE::StateTree::DebugIndentSize, TEXT(""), *Eval.Name.ToString()); Eval.Evaluate(*this, EvalType, DeltaTime); } VisitedStates[CurrentHandle.Index] = true; } } EStateTreeRunStatus FStateTreeExecutionContext::TickTasks(FStateTreeDataView Storage, const FStateTreeHandle CurrentState, const float DeltaTime) { CSV_SCOPED_TIMING_STAT_EXCLUSIVE(StateTreeCtxTickTasks); if (!CurrentState.IsValid()) { return EStateTreeRunStatus::Failed; } TStaticArray States; const int32 NumStates = GetActiveStates(CurrentState, States); EStateTreeRunStatus Result = EStateTreeRunStatus::Running; int32 NumTotalTasks = 0; for (int32 Index = 0; Index < NumStates && Result != EStateTreeRunStatus::Failed; Index++) { const FStateTreeHandle CurrentHandle = States[Index]; const FBakedStateTreeState& State = StateTree->States[CurrentHandle.Index]; STATETREE_CLOG(State.TasksNum > 0, Verbose, TEXT("%*sTicking Tasks of state '%s'"), Index*UE::StateTree::DebugIndentSize, TEXT(""), *DebugGetStatePath(States, Index)); // Tick Tasks for (int32 TaskIndex = 0; TaskIndex < int32(State.TasksNum); TaskIndex++) { const FStateTreeTaskBase& Task = GetItem(int32(State.TasksBegin) + TaskIndex); const FStateTreeDataView TaskInstanceView = GetInstanceData(Storage, Task.bInstanceIsObject, Task.InstanceIndex); DataViews[Task.DataViewIndex] = TaskInstanceView; // Copy bound properties. if (Task.BindingsBatch.IsValid()) { StateTree->PropertyBindings.CopyTo(DataViews, Task.BindingsBatch.Index, TaskInstanceView); } STATETREE_LOG(Verbose, TEXT("%*s Tick: '%s'"), Index*UE::StateTree::DebugIndentSize, TEXT(""), *Task.Name.ToString()); const EStateTreeRunStatus TaskResult = Task.Tick(*this, DeltaTime); // TODO: Add more control over which states can control the failed/succeeded result. if (TaskResult != EStateTreeRunStatus::Running) { Result = TaskResult; } if (TaskResult == EStateTreeRunStatus::Failed) { break; } } NumTotalTasks += State.TasksNum; } if (NumTotalTasks == 0) { // No tasks, done ticking. Result = EStateTreeRunStatus::Succeeded; } return Result; } bool FStateTreeExecutionContext::TestAllConditions(FStateTreeDataView Storage, const uint32 ConditionsOffset, const uint32 ConditionsNum) { CSV_SCOPED_TIMING_STAT_EXCLUSIVE(StateTreeCtxTestConditions); for (uint32 i = 0; i < ConditionsNum; i++) { const FStateTreeConditionBase& Cond = GetItem(ConditionsOffset + i); const FStateTreeDataView CondInstanceView = GetInstanceData(Storage, Cond.bInstanceIsObject, Cond.InstanceIndex); DataViews[Cond.DataViewIndex] = CondInstanceView; // Copy bound properties. if (Cond.BindingsBatch.IsValid()) { StateTree->PropertyBindings.CopyTo(DataViews, Cond.BindingsBatch.Index, CondInstanceView); } if (!Cond.TestCondition(*this)) { return false; } } return true; } FStateTreeTransitionResult FStateTreeExecutionContext::TriggerTransitions(FStateTreeDataView Storage, const FStateTreeStateStatus CurrentStatus, const int32 Depth) { FStateTreeExecutionState& Exec = GetExecState(Storage); EStateTreeTransitionEvent Event = EStateTreeTransitionEvent::OnCondition; if (CurrentStatus.RunStatus == EStateTreeRunStatus::Succeeded) { Event = EStateTreeTransitionEvent::OnSucceeded; } else if (CurrentStatus.RunStatus == EStateTreeRunStatus::Failed) { Event = EStateTreeTransitionEvent::OnFailed; } // Walk towards root and check all transitions along the way. for (FStateTreeHandle Handle = CurrentStatus.State; Handle.IsValid(); Handle = StateTree->States[Handle.Index].Parent) { const FBakedStateTreeState& State = StateTree->States[Handle.Index]; for (uint8 i = 0; i < State.TransitionsNum; i++) { // All transition conditions must pass const int16 TransitionIndex = State.TransitionsBegin + i; const FBakedStateTransition& Transition = StateTree->Transitions[TransitionIndex]; if (EnumHasAllFlags(Transition.Event, Event) && TestAllConditions(Storage, Transition.ConditionsBegin, Transition.ConditionsNum)) { // If a transition has delay, we stop testing other transitions, but the transition will not pass the condition until the delay time passes. if (Transition.GateDelay > 0) { if (Exec.GatedTransitionIndex != TransitionIndex) { Exec.GatedTransitionIndex = TransitionIndex; Exec.GatedTransitionTime = FMath::RandRange(0.0f, Transition.GateDelay * 0.1f); // TODO: we need variance too. BeginGatedTransition(Exec); STATETREE_LOG(Verbose, TEXT("Gated transition triggered from '%s' (%s) -> '%s' %.1fs"), *GetSafeStateName(CurrentStatus.State), *State.Name.ToString(), *GetSafeStateName(Transition.State), Exec.GatedTransitionTime); } // Keep on updating current state, until we have tried to trigger if (Exec.GatedTransitionTime > 0.0f) { return FStateTreeTransitionResult(CurrentStatus, FStateTreeHandle::Invalid); } STATETREE_LOG(Verbose, TEXT("Passed gated transition from '%s' (%s) -> '%s'"), *GetSafeStateName(CurrentStatus.State), *State.Name.ToString(), *GetSafeStateName(Transition.State)); } if (Transition.Type == EStateTreeTransitionType::GotoState || Transition.Type == EStateTreeTransitionType::NextState) { FStateTreeTransitionResult Result = SelectState(Storage, CurrentStatus, Transition.State, Transition.State, Depth + 1); if (Result.Next.IsValid()) { STATETREE_LOG(Verbose, TEXT("Transition on state '%s' (%s) -[%s]-> state '%s'"), *GetSafeStateName(CurrentStatus.State), *State.Name.ToString(), *GetSafeStateName(Result.Target), *GetSafeStateName(Result.Next)); return Result; } } else if (Transition.Type == EStateTreeTransitionType::NotSet) { // NotSet is no-operation, but can be used to mask a transition at parent state. Returning unset keeps updating current state. return FStateTreeTransitionResult(CurrentStatus, FStateTreeHandle::Invalid); } else if (Transition.Type == EStateTreeTransitionType::Succeeded) { STATETREE_LOG(Verbose, TEXT("Stop tree execution from state '%s' (%s): Succeeded"), *GetSafeStateName(CurrentStatus.State), *State.Name.ToString()); return FStateTreeTransitionResult(CurrentStatus, FStateTreeHandle::Succeeded); } else { STATETREE_LOG(Verbose, TEXT("Stop tree execution from state '%s' (%s): Failed"), *GetSafeStateName(CurrentStatus.State), *State.Name.ToString()); return FStateTreeTransitionResult(CurrentStatus, FStateTreeHandle::Failed); } } else if (Exec.GatedTransitionIndex == TransitionIndex) { // If the current transition was gated transition, reset it if the condition failed. Exec.GatedTransitionIndex = INDEX_NONE; Exec.GatedTransitionTime = 0.0f; } } } if (CurrentStatus.RunStatus != EStateTreeRunStatus::Running) { STATETREE_LOG(Error, TEXT("%s: Default transitions on state '%s' could not be triggered. '%s' using StateTree '%s'."), ANSI_TO_TCHAR(__FUNCTION__), *GetSafeStateName(CurrentStatus.State), *GetNameSafe(Owner), *GetNameSafe(StateTree)); return FStateTreeTransitionResult(CurrentStatus, FStateTreeHandle::Failed); } // No transition triggered, keep on updating current state. return FStateTreeTransitionResult(CurrentStatus, FStateTreeHandle::Invalid); } FStateTreeTransitionResult FStateTreeExecutionContext::SelectState(FStateTreeDataView Storage, const FStateTreeStateStatus InitialStateStatus, const FStateTreeHandle InitialTargetState, const FStateTreeHandle NextState, const int Depth) { if (!NextState.IsValid()) { // Trying to select non-existing state. STATETREE_LOG(Error, TEXT("%s: Trying to select invalid state from '%s' via '%s. '%s' using StateTree '%s'."), ANSI_TO_TCHAR(__FUNCTION__), *GetStateStatusString(InitialStateStatus), *GetSafeStateName(InitialTargetState), *GetNameSafe(Owner), *GetNameSafe(StateTree)); return FStateTreeTransitionResult(InitialStateStatus, InitialTargetState, FStateTreeHandle::Invalid); } const FBakedStateTreeState& State = StateTree->States[NextState.Index]; // Make sure all the evaluators for the target state are up to date. TickEvaluators(Storage, NextState, EStateTreeEvaluationType::PreSelect, 0.0f); // Check that the state can be entered if (TestAllConditions(Storage, State.EnterConditionsBegin, State.EnterConditionsNum)) { // If the state has children, proceed to select children. if (State.HasChildren()) { for (uint16 ChildState = State.ChildrenBegin; ChildState < State.ChildrenEnd; ChildState = StateTree->States[ChildState].GetNextSibling()) { const FStateTreeTransitionResult ChildResult = SelectState(Storage, InitialStateStatus, InitialTargetState, FStateTreeHandle(ChildState), Depth + 1); if (ChildResult.Next.IsValid()) { // Selection succeeded return ChildResult; } } } else { // Select this state. return FStateTreeTransitionResult(InitialStateStatus, InitialTargetState, NextState); } } // Nothing got selected. return FStateTreeTransitionResult(InitialStateStatus, InitialTargetState, FStateTreeHandle::Invalid); } int32 FStateTreeExecutionContext::GetActiveStates(const FStateTreeHandle StateHandle, TStaticArray& OutStateHandles) const { if (StateHandle == FStateTreeHandle::Succeeded || StateHandle == FStateTreeHandle::Failed || StateHandle == FStateTreeHandle::Invalid) { return 0; } int32 NumStates = 0; FStateTreeHandle CurrentHandle = StateHandle; while (CurrentHandle.IsValid() && NumStates < OutStateHandles.Num()) { OutStateHandles[NumStates++] = CurrentHandle; CurrentHandle = StateTree->States[CurrentHandle.Index].Parent; } Algo::Reverse(OutStateHandles.GetData(), NumStates); return NumStates; } FString FStateTreeExecutionContext::GetSafeStateName(const FStateTreeHandle State) const { check(StateTree); if (State == FStateTreeHandle::Invalid) { return TEXT("(State Invalid)"); } else if (State == FStateTreeHandle::Succeeded) { return TEXT("(State Succeeded)"); } else if (State == FStateTreeHandle::Failed) { return TEXT("(State Failed)"); } else if (StateTree->States.IsValidIndex(State.Index)) { return *StateTree->States[State.Index].Name.ToString(); } return TEXT("(Unknown)"); } FString FStateTreeExecutionContext::DebugGetStatePath(const TArrayView ActiveStateHandles, const int32 ActiveStateIndex) const { FString StatePath; if (!ensureMsgf(ActiveStateHandles.IsValidIndex(ActiveStateIndex), TEXT("Provided index must be valid"))) { return StatePath; } for (int32 i = 0; i <= ActiveStateIndex; i++) { const FBakedStateTreeState& State = StateTree->States[ActiveStateHandles[i].Index]; StatePath.Appendf(TEXT("%s%s"), i == 0 ? TEXT("") : TEXT("."), *State.Name.ToString()); } return StatePath; } FString FStateTreeExecutionContext::GetStateStatusString(const FStateTreeStateStatus StateStatus) const { // Invalid (null) state in status refers to the whole tree. const FString StateName = GetSafeStateName(StateStatus.State); switch(StateStatus.RunStatus) { case EStateTreeRunStatus::Unset: return StateName + TEXT("Unset"); case EStateTreeRunStatus::Running: return StateName + TEXT("Running"); case EStateTreeRunStatus::Succeeded: return StateName + TEXT("Succeeded"); case EStateTreeRunStatus::Failed: return StateName + TEXT("Failed"); default: return StateName + TEXT("(Unknown)"); } } EStateTreeRunStatus FStateTreeExecutionContext::GetLastTickStatus(FStateTreeDataView ExternalStorage) const { const FStateTreeExecutionState& Exec = GetExecState(SelectStorage(ExternalStorage)); return Exec.LastTickStatus; } void FStateTreeExecutionContext::AddStructReferencedObjects(FReferenceCollector& Collector) { if (StorageType == EStateTreeStorage::Internal) { AddStructReferencedObjects(FStateTreeDataView(StorageInstance), Collector); } } void FStateTreeExecutionContext::AddStructReferencedObjects(const FStateTreeDataView Storage, FReferenceCollector& Collector) { if (Storage.IsValid()) { FStateTreeExecutionState& Exec = GetExecState(Storage); Collector.AddReferencedObjects(Exec.InstanceObjects); } } #if WITH_GAMEPLAY_DEBUGGER FString FStateTreeExecutionContext::GetDebugInfoString(FStateTreeDataView ExternalStorage) const { if (!StateTree) { return FString(TEXT("No StateTree asset.")); } FStateTreeDataView Storage = SelectStorage(ExternalStorage); FStateTreeExecutionState& Exec = GetExecState(Storage); FString DebugString = FString::Printf(TEXT("StateTree (asset: '%s')\n"), *GetNameSafe(StateTree)); DebugString += TEXT("Status: "); switch (Exec.TreeRunStatus) { case EStateTreeRunStatus::Failed: DebugString += TEXT("Failed\n"); break; case EStateTreeRunStatus::Succeeded: DebugString += TEXT("Succeeded\n"); break; case EStateTreeRunStatus::Running: DebugString += TEXT("Running\n"); break; default: DebugString += TEXT("--\n"); } // Active States TStaticArray ActiveStates; const int32 NumStates = GetActiveStates(Exec.CurrentState, ActiveStates); DebugString += TEXT("Current State:\n"); for (int32 Index = 0; Index < NumStates; Index++) { FStateTreeHandle Handle = ActiveStates[Index]; if (Handle.IsValid()) { const FBakedStateTreeState& State = StateTree->States[Handle.Index]; DebugString += FString::Printf(TEXT("[%s]\n"), *State.Name.ToString()); if (State.TasksNum > 0) { DebugString += TEXT("\nTasks:\n"); for (int32 j = 0; j < int32(State.TasksNum); j++) { const FStateTreeTaskBase& Task = GetItem(int32(State.TasksBegin) + j); Task.AppendDebugInfoString(DebugString, *this); } } if (State.EvaluatorsNum > 0) { DebugString += TEXT("\nEvaluators:\n"); for (int32 EvalIndex = 0; EvalIndex < int32(State.EvaluatorsNum); EvalIndex++) { const FStateTreeEvaluatorBase& Eval = GetItem(int32(State.EvaluatorsBegin) + EvalIndex); Eval.AppendDebugInfoString(DebugString, *this); } } } } return DebugString; } #endif // WITH_GAMEPLAY_DEBUGGER #if WITH_STATETREE_DEBUG void FStateTreeExecutionContext::DebugPrintInternalLayout(FStateTreeDataView ExternalStorage) { LOG_SCOPE_VERBOSITY_OVERRIDE(LogStateTree, ELogVerbosity::Log); if (StateTree == nullptr) { UE_LOG(LogStateTree, Log, TEXT("No StateTree asset.")); return; } FString DebugString = FString::Printf(TEXT("StateTree (asset: '%s')\n"), *GetNameSafe(StateTree)); // Tree items (e.g. tasks, evaluators, conditions) DebugString += FString::Printf(TEXT("\nItems(%d)\n"), StateTree->Items.Num()); for (const FInstancedStruct& Item : StateTree->Items) { DebugString += FString::Printf(TEXT(" %s\n"), Item.IsValid() ? *Item.GetScriptStruct()->GetName() : TEXT("null")); } // Instance storage data (e.g. tasks, evaluators, conditions) DebugString += FString::Printf(TEXT("\nInstance Data(%d)\n"), StateTree->Instances.Num()); for (const FInstancedStruct& Data : StateTree->Instances) { DebugString += FString::Printf(TEXT(" %s\n"), Data.IsValid() ? *Data.GetScriptStruct()->GetName() : TEXT("null")); } // Instance storage offsets (e.g. tasks, evaluators, conditions) DebugString += FString::Printf(TEXT("\nInstance Data Offsets(%d)\n [ %-40s | %-6s ]\n"), StateTree->InstanceStorageOffsets.Num(), TEXT("Name"), TEXT("Offset")); for (const FStateTreeInstanceStorageOffset& Offset : StateTree->InstanceStorageOffsets) { DebugString += FString::Printf(TEXT(" | %-40s | %6d |\n"), Offset.Struct ? *Offset.Struct->GetName() : TEXT("null"), Offset.Offset); } // External data (e.g. fragments, subsystems) DebugString += FString::Printf(TEXT("\nExternal Data(%d)\n [ %-40s | %-8s | %5s ]\n"), StateTree->ExternalDataDescs.Num(), TEXT("Name"), TEXT("Optional"), TEXT("Index")); for (const FStateTreeExternalDataDesc& Desc : StateTree->ExternalDataDescs) { DebugString += FString::Printf(TEXT(" | %-40s | %8s | %5d |\n"), Desc.Struct ? *Desc.Struct->GetName() : TEXT("null"), *UEnum::GetValueAsString(Desc.Requirement), Desc.Handle.DataViewIndex); } // Bindings StateTree->PropertyBindings.DebugPrintInternalLayout(DebugString); // Transitions DebugString += FString::Printf(TEXT("\nTransitions(%d)\n [ %-3s | %15s | %-40s | %-40s | %-8s ]\n"), StateTree->Transitions.Num() , TEXT("Idx"), TEXT("State"), TEXT("Transition Type"), TEXT("Transition Event"), TEXT("Num Cond")); for (const FBakedStateTransition& Transition : StateTree->Transitions) { DebugString += FString::Printf(TEXT(" | %3d | %15s | %-40s | %-40s | %8d |\n"), Transition.ConditionsBegin, *Transition.State.Describe(), *UEnum::GetValueAsString(Transition.Type), *UEnum::GetValueAsString(Transition.Event), Transition.ConditionsNum); } // DataViews DebugString += FString::Printf(TEXT("\nDataViews(%d)\n"), DataViews.Num()); for (const FStateTreeDataView& DataView : DataViews) { DebugString += FString::Printf(TEXT(" [%s]\n"), DataView.IsValid() ? *DataView.GetStruct()->GetName() : TEXT("null")); } // States FStateTreeDataView Storage = SelectMutableStorage(ExternalStorage); DebugString += FString::Printf(TEXT("\nStates(%d)\n" " [ %-30s | %15s | %5s [%3s:%-3s[ | Begin Idx : %4s %4s %4s %4s | Num : %4s %4s %4s %4s | Transitions : %-16s %-40s %-16s %-40s ]\n"), StateTree->States.Num(), TEXT("Name"), TEXT("Parent"), TEXT("Child"), TEXT("Beg"), TEXT("End"), TEXT("Cond"), TEXT("Tr"), TEXT("Tsk"), TEXT("Evt"), TEXT("Cond"), TEXT("Tr"), TEXT("Tsk"), TEXT("Evt"), TEXT("Done State"), TEXT("Done Type"), TEXT("Failed State"), TEXT("Failed Type") ); for (const FBakedStateTreeState& State : StateTree->States) { DebugString += FString::Printf(TEXT(" | %-30s | %15s | %5s [%3d:%-3d[ | %9s %4d %4d %4d %4d | %3s %4d %4d %4d %4d | %11s %-16s %-40s %-16s %-40s |\n"), *State.Name.ToString(), *State.Parent.Describe(), TEXT(""), State.ChildrenBegin, State.ChildrenEnd, TEXT(""), State.EnterConditionsBegin, State.TransitionsBegin, State.TasksBegin, State.EvaluatorsBegin, TEXT(""), State.EnterConditionsNum, State.TransitionsNum, State.TasksNum, State.EvaluatorsNum, TEXT(""), *State.StateDoneTransitionState.Describe(), *StaticEnum()->GetValueAsString(State.StateDoneTransitionType), *State.StateFailedTransitionState.Describe(), *StaticEnum()->GetValueAsString(State.StateFailedTransitionType)); } DebugString += FString::Printf(TEXT("\nStates\n [ %-30s | %-12s | %-30s | %15s | %10s ]\n"), TEXT("State"), TEXT("Type"), TEXT("Name"), TEXT("Bindings"), TEXT("Struct Idx")); for (const FBakedStateTreeState& State : StateTree->States) { // Evaluators if (State.EvaluatorsNum) { for (int32 EvalIndex = 0; EvalIndex < State.EvaluatorsNum; EvalIndex++) { const FStateTreeEvaluatorBase& Eval = GetItem(State.EvaluatorsBegin + EvalIndex); DebugString += FString::Printf(TEXT(" | %-30s | %-12s | %-30s | %15s | %10d |\n"), *State.Name.ToString(), TEXT(" Evaluator"), *Eval.Name.ToString(), *Eval.BindingsBatch.Describe(), Eval.DataViewIndex); } } // Tasks if (State.TasksNum) { for (int32 TaskIndex = 0; TaskIndex < State.TasksNum; TaskIndex++) { const FStateTreeTaskBase& Task = GetItem(State.TasksBegin + TaskIndex); DebugString += FString::Printf(TEXT(" | %-30s | %-12s | %-30s | %15s | %10d |\n"), *State.Name.ToString(), TEXT(" Task"), *Task.Name.ToString(), *Task.BindingsBatch.Describe(), Task.DataViewIndex); } } } UE_LOG(LogStateTree, Log, TEXT("%s"), *DebugString); } FString FStateTreeExecutionContext::GetActiveStateName(FStateTreeDataView ExternalStorage) const { if (!StateTree) { return FString(TEXT("")); } const FStateTreeDataView Storage = SelectStorage(ExternalStorage); FStateTreeExecutionState& Exec = GetExecState(Storage); FString FullStateName; // Active States TStaticArray ActiveStates; const int32 NumStates = GetActiveStates(Exec.CurrentState, ActiveStates); for (int32 Index = 0; Index < NumStates; Index++) { FStateTreeHandle Handle = ActiveStates[Index]; if (Handle.IsValid()) { const FBakedStateTreeState& State = StateTree->States[Handle.Index]; if (Index > 0) { FullStateName += TEXT("\n"); } FullStateName += FString::Printf(TEXT("%*s-"), Index * 3, TEXT("")); // Indent FullStateName += *State.Name.ToString(); } } switch (Exec.TreeRunStatus) { case EStateTreeRunStatus::Failed: FullStateName += TEXT(" FAILED\n"); break; case EStateTreeRunStatus::Succeeded: FullStateName += TEXT(" SUCCEEDED\n"); break; case EStateTreeRunStatus::Running: // Empty break; default: FullStateName += TEXT("--\n"); } return FullStateName; } #endif // WITH_STATETREE_DEBUG #undef STATETREE_LOG #undef STATETREE_CLOG