FSMStateMachine

Module: SMSystem

#include <SMStateMachine.h>

Inherits from FSMState_Base, FSMNode_Base

Description

struct FSMStateMachine;

State machines contain states and transitions. When a transition succeeds the current state advances to the next. FSMStateMachine is also considered a state since it inherits from FSMState_Base, making it possible to nest state machines.

When configured as a reference this will defer handling to the SMInstance (or in some cases the RootStateMachine) of the referenced Blueprint.

Public Classes

	Name
struct	FGetNodeArgs
struct	FStateScopingArgs

Public Functions

	Name
	FSMStateMachine()
virtual void	Initialize(UObject * Instance) override
virtual void	InitializeGraphFunctions() override
virtual void	Reset() override
virtual void	ResetReadStates() override
virtual bool	StartState() override
virtual bool	UpdateState(float DeltaSeconds) override
virtual bool	EndState(float DeltaSeconds, const FSMTransition * TransitionToTake =nullptr) override
virtual void	ExecuteInitializeNodes() override
virtual void	ExecuteShutdownNodes() override
virtual void	OnStartedByInstance(USMInstance * Instance) override
virtual void	OnStoppedByInstance(USMInstance * Instance) override
virtual void	CalculatePathGuid(TMap< FString, int32 > & InOutMappedPaths, bool bUseGuidCache =false) override
virtual void	RunConstructionScripts() override
virtual bool	IsInEndState() const override
virtual bool	IsEndState() const override
virtual bool	IsStateMachine() const override
virtual bool	IsNodeInstanceClassCompatible(UClass * NewNodeInstanceClass) const override
virtual USMNodeInstance *	GetNodeInstance() const override
virtual USMNodeInstance *	GetOrCreateNodeInstance() override
virtual bool	CanEverCreateNodeInstance() const override
virtual UClass *	GetDefaultNodeInstanceClass() const override
virtual FSMNode_Base *	GetOwnerNode() const override
virtual void	SetStartTime(const FDateTime & InStartTime) override
virtual void	SetEndTime(const FDateTime & InEndTime) override
virtual void	SetServerTimeInState(float InTime) override
bool	IsStateMachineInEndState() const
bool	HasStateMachineReachedEndStateForRun() const
void	AddState(FSMState_Base * State)
void	AddTransition(FSMTransition * Transition)
void	AddInitialState(FSMState_Base * State)
void	AddTemporaryInitialState(FSMState_Base * State)
void	ClearTemporaryInitialStates(bool bRecursive =false)
void	SetFromTemporaryInitialStates()
bool	ContainsActiveState(FSMState_Base * StateToCheck) const
bool	HasActiveStates() const
bool	HasTemporaryEntryStates() const
FSMState_Base *	GetSingleActiveState() const
TArray< FSMState_Base * >	GetActiveStates() const
TArray< FSMState_Base * >	GetAllNestedActiveStates() const
TArray< FSMNode_Base * >	GetAllNodes(const FGetNodeArgs & InArgs =FGetNodeArgs()) const
TArray< FSMNode_Base * >	GetAllNodes(bool bIncludeNested, bool bForwardToReference =false) const
const TArray< FSMState_Base * > &	GetStates() const
const TArray< FSMTransition * > &	GetTransitions() const
const TArray< FSMState_Base * > &	GetEntryStates() const
TArray< FSMState_Base * >	GetInitialStates() const
FSMState_Base *	GetSingleInitialState() const
FSMState_Base *	GetSingleInitialTemporaryState() const
TArray< FSMState_Base * >	GetAllNestedInitialTemporaryStates() const
FSMState_Base *	FindState(const FGuid & StateGuid) const
void	SetNetworkedConditions(TScriptInterface< ISMStateMachineNetworkedInterface > InNetworkInterface, bool bEvaluateTransitions, bool bTakeTransitions, bool bCanExecuteStateLogic)
void	ProcessStates(float DeltaSeconds, bool bForceTransitionEvaluationOnly =false, const FGuid & InCurrentRunGuid =FGuid(), const FStateScopingArgs & InStateScopingArgs =FStateScopingArgs())
bool	ProcessTransition(FSMTransition * Transition, FSMState_Base * SourceState, FSMState_Base * DestinationState, const FSMTransitionTransaction * Transaction, float DeltaSeconds, FDateTime * CurrentTime =nullptr)
bool	EvaluateAndTakeTransitionChain(FSMTransition * InFirstTransition)
bool	TakeTransitionChain(const TArray< FSMTransition * > & InTransitionChain)
bool	TryStartState(FSMState_Base * InState, bool * bOutSafeToCheckTransitions =nullptr)
bool	TryTakeTransitionChain(const TArray< FSMTransition * > & InTransitionChain, float DeltaSeconds, bool bStateJustStarted =false, FSMState_Base ** OutDestinationState =nullptr)
bool	CanProcessExternalTransition() const
bool	IsWaitingForUpdate() const
void	SetReuseCurrentState(bool bValue, bool bOnlyWhenNotInEndState)
bool	CanReuseCurrentState() const
void	SetClassReference(UClass * ClassReference)
UClass *	GetClassReference() const
void	SetInstanceReference(USMInstance * InstanceReference)
USMInstance *	GetInstanceReference() const
void	SetReferencedTemplateName(const FName & Name)
const FName &	GetReferencedTemplateName() const
void	SetReferencedBy(USMInstance * FromInstance, FSMStateMachine * FromStateMachine)
USMInstance *	GetReferencedByInstance() const
FSMStateMachine *	GetReferencedByStateMachine() const
void	SetDynamicReferenceVariableName(const FName & InVariableName)
const FName &	GetDynamicReferenceVariableName() const
bool	IsDynamicReference() const
bool	IsNetworked() const
ISMStateMachineNetworkedInterface *	TryGetNetworkInterfaceIfNetworked() const
const TMap< FString, FSMState_Base * > &	GetStateNameMap() const
void	AddActiveState(FSMState_Base * State)
void	RemoveActiveState(FSMState_Base * State)
virtual void	ResetGeneratedValues() override

Protected Functions

	Name
virtual void	InitializeFunctionHandlers() override
virtual void	NotifyInstanceStateHasStarted() override
void	SetCurrentState(FSMState_Base * ToState, FSMState_Base * FromState, FSMState_Base * SourceState =nullptr)
void	TryNotifyEndStateReached()

Public Attributes

	Name
uint8	bHasAdditionalLogic
uint8	bReuseCurrentState
uint8	bOnlyReuseIfNotEndState
uint8	bAllowIndependentTick
uint8	bCallReferenceTickOnManualUpdate
uint8	bWaitForEndState

Additional inherited members

Public Functions inherited from FSMState_Base

	Name
virtual void	UpdateReadStates() override
	FSMState_Base()
const TArray< FSMTransition * > &	GetOutgoingTransitions() const
const TArray< FSMTransition * > &	GetIncomingTransitions() const
void	GetAllTransitionChains(TArray< FSMTransition * > & OutTransitions) const
virtual bool	GetValidTransition(TArray< TArray< FSMTransition * > > & Transitions)
virtual bool	HasUpdated() const
virtual bool	IsConduit() const
bool	IsRootNode() const
float	GetActiveTime() const
void	SetCanExecuteLogic(bool bValue)
bool	CanExecuteLogic() const
virtual bool	CanExecuteGraphProperties(uint32 OnEvent, const USMStateInstance_Base * ForTemplate) const override
bool	CanEvaluateTransitionsOnTick() const
void	SortTransitions()
void	SetTransitionToTake(const FSMTransition * Transition)
const FSMTransition *	GetTransitionToTake() const
void	SetPreviousActiveState(FSMState_Base * InPreviousState)
void	SetPreviousActiveTransition(FSMTransition * InPreviousTransition)
FSMState_Base *	GetPreviousActiveState() const
FSMTransition *	GetPreviousActiveTransition() const
void	NotifyOfParallelReentry(bool bValue =true)
bool	HasBeenReenteredFromParallelState() const
bool	IsStateEnding() const
const FDateTime &	GetStartTime() const
const FDateTime &	GetEndTime() const
double	GetStartCycle() const

Protected Functions inherited from FSMState_Base

	Name
void	AddOutgoingTransition(FSMTransition * Transition)
void	AddIncomingTransition(FSMTransition * Transition)
void	InitializeTransitions()
void	ShutdownTransitions()
virtual void	FirePreStartEvents()
virtual void	FirePostStartEvents()

Public Attributes inherited from FSMState_Base

	Name
uint16	bIsRootNode
uint16	bAlwaysUpdate
uint16	bEvalTransitionsOnStart
uint16	bDisableTickTransitionEvaluation
uint16	bStayActiveOnStateChange
uint16	bAllowParallelReentry
uint16	bCanBeEndState

Protected Attributes inherited from FSMState_Base

	Name
uint16	bReenteredByParallelState
uint16	bCanExecuteLogic
uint16	bIsStateEnding
FSMState_Base *	PreviousActiveState
FSMTransition *	PreviousActiveTransition
FDateTime	StartTime
FDateTime	EndTime

Friends inherited from FSMState_Base

	Name
struct	FSMTransition(FSMTransition )

Public Functions inherited from FSMNode_Base

	Name
const FSMNode_FunctionHandlers *	GetFunctionHandlers() const
virtual void	UpdateReadStates()
	FSMNode_Base()
virtual	~FSMNode_Base() =default
	FSMNode_Base(const FSMNode_Base & Node) =default
bool	HaveGraphFunctionsInitialized() const
bool	IsInitializedForRun() const
const FGuid &	GetNodeGuid() const
void	GenerateNewNodeGuid()
const FGuid &	GetGuid() const
FString	GetGuidPath(TMap< FString, int32 > & InOutMappedPaths) const
FGuid	CalculatePathGuidConst() const
void	GenerateNewNodeGuidIfNotSet()
void	SetNodeGuid(const FGuid & NewGuid)
void	SetOwnerNodeGuid(const FGuid & NewGuid)
const FGuid &	GetOwnerNodeGuid() const
void	SetOwnerNode(FSMNode_Base * Owner)
USMInstance *	GetOwningInstance() const
void	CreateNodeInstance()
void	CreateStackInstances()
void	SetNodeInstanceClass(UClass * NewNodeInstanceClass)
const TArray< TObjectPtr< USMNodeInstance > > &	GetStackInstancesConst() const
TArray< TObjectPtr< USMNodeInstance > > &	GetStackInstances()
USMNodeInstance *	GetNodeInStack(int32 Index) const
UClass *	GetNodeInstanceClass() const
bool	IsUsingDefaultNodeClass() const
void	AddVariableGraphProperty(const FSMGraphProperty_Base_Runtime & GraphProperty, const FGuid & OwningTemplateGuid)
void	SetNodeName(const FString & Name)
const FString &	GetNodeName() const
void	SetTemplateName(const FName & Name)
FName	GetTemplateName(USMNodeInstance * InNodeInstance =nullptr) const
void	AddStackTemplateName(const FName & Name, UClass * TemplateClass)
virtual bool	IsActive() const
float	GetServerTimeInState() const
virtual bool	CanExecuteGraphProperties(uint32 OnEvent, const class USMStateInstance_Base * ForTemplate) const
virtual bool	TryExecuteGraphProperties(uint32 OnEvent)
void	ExecuteGraphProperties(USMNodeInstance * ForNodeInstance, const FGuid * ForTemplateGuid)
const TArray< FSMGraphProperty_Base_Runtime * > &	GetGraphProperties() const
const TMap< FGuid, FSMGraphPropertyTemplateOwner > &	GetTemplateGraphProperties() const
virtual void	TryResetVariables()
virtual bool	IsDebugActive() const
virtual bool	WasDebugActive() const
virtual void	EditorShutdown()
FName	GetNodeGuidPropertyName()

Protected Functions inherited from FSMNode_Base

	Name
virtual void	PrepareGraphExecution()
virtual void	SetActive(bool bValue)
void	CreateGraphProperties()
void	CreateGraphPropertiesForTemplate(USMNodeInstance * Template, const TMap< FGuid, FSMGraphProperty_Base_Runtime * > & MappedGraphPropertyInstances)

Public Attributes inherited from FSMNode_Base

	Name
bool	bValidateGuids
float	TimeInState
bool	bIsInEndState
bool	bHasUpdated
int32	DuplicateId
FVector2D	NodePosition
uint8	bHasInputEvents
bool	bWasActive

Protected Attributes inherited from FSMNode_Base

	Name
FSMNode_FunctionHandlers *	FunctionHandlers
FGuid	Guid
FGuid	OwnerGuid
FGuid	PathGuid
FSMNode_Base *	OwnerNode
FString	NodeName
FName	TemplateName
TArray< FName >	StackTemplateNames
TArray< TObjectPtr< USMNodeInstance > >	StackNodeInstances
TArray< TObjectPtr< UClass > >	NodeStackClasses
TObjectPtr< USMInstance >	OwningInstance
TObjectPtr< USMNodeInstance >	NodeInstance
TArray< FSMGraphProperty_Base_Runtime * >	GraphProperties
TMap< FGuid, FSMGraphPropertyTemplateOwner >	TemplateVariableGraphProperties
TObjectPtr< UClass >	NodeInstanceClass

Friends inherited from FSMNode_Base

	Name
class	FSMEditorConstructionManager

Public Functions Documentation

function FSMStateMachine

FSMStateMachine()

---

function Initialize

virtual void Initialize(
    UObject * Instance
) override

Initialize specific properties and node instances.

Reimplements: FSMState_Base::Initialize

---

function InitializeGraphFunctions

virtual void InitializeGraphFunctions() override

Initialize all graph evaluator functions. Must be called from GameThread!

Reimplements: FSMState_Base::InitializeGraphFunctions

---

function Reset

virtual void Reset() override

Resets persistent data.

Reimplements: FSMState_Base::Reset

---

function ResetReadStates

virtual void ResetReadStates() override

Reimplements: FSMState_Base::ResetReadStates

---

function StartState

virtual bool StartState() override

Sets the state as active and begins execution.

Reimplements: FSMState_Base::StartState

---

function UpdateState

virtual bool UpdateState(
    float DeltaSeconds
) override

Runs the update execution.

Reimplements: FSMState_Base::UpdateState

---

function EndState

virtual bool EndState(
    float DeltaSeconds,
    const FSMTransition * TransitionToTake =nullptr
) override

Runs the end state execution. Transition to take is so the state knows where it is going only.

Reimplements: FSMState_Base::EndState

---

function ExecuteInitializeNodes

virtual void ExecuteInitializeNodes() override

Reimplements: FSMState_Base::ExecuteInitializeNodes

---

function ExecuteShutdownNodes

virtual void ExecuteShutdownNodes() override

Reimplements: FSMNode_Base::ExecuteShutdownNodes

---

function OnStartedByInstance

virtual void OnStartedByInstance(
    USMInstance * Instance
) override

Called when the blueprint owning this node is started.

Reimplements: FSMState_Base::OnStartedByInstance

---

function OnStoppedByInstance

virtual void OnStoppedByInstance(
    USMInstance * Instance
) override

Called when the blueprint owning this node has stopped.

Reimplements: FSMState_Base::OnStoppedByInstance

---

function CalculatePathGuid

virtual void CalculatePathGuid(
    TMap< FString, int32 > & InOutMappedPaths,
    bool bUseGuidCache =false
) override

Calculate the value returned from GetGuid(). Gets all owner nodes and builds a path to this node. Hashes the path and sets PathGuid.

Reimplements: FSMNode_Base::CalculatePathGuid

---

function RunConstructionScripts

virtual void RunConstructionScripts() override

Reimplements: FSMNode_Base::RunConstructionScripts

---

function IsInEndState

virtual bool IsInEndState() const override

Deprecated:

Use IsStateMachineInEndState() instead.

Reimplements: FSMState_Base::IsInEndState

---

function IsEndState

virtual bool IsEndState() const override

If the state itself is an end state.

Reimplements: FSMState_Base::IsEndState

---

function IsStateMachine

inline virtual bool IsStateMachine() const override

Easy way to check if this state struct is a state machine.

Reimplements: FSMState_Base::IsStateMachine

---

function IsNodeInstanceClassCompatible

virtual bool IsNodeInstanceClassCompatible(
    UClass * NewNodeInstanceClass
) const override

Derived nodes should overload and check for the correct type.

Reimplements: FSMState_Base::IsNodeInstanceClassCompatible

---

function GetNodeInstance

virtual USMNodeInstance * GetNodeInstance() const override

Return the current node instance. Only valid after initialization and may be nullptr.

Reimplements: FSMNode_Base::GetNodeInstance

---

function GetOrCreateNodeInstance

virtual USMNodeInstance * GetOrCreateNodeInstance() override

Create a node instance on demand if needed. Only required for default node classes. Initialization should be completed before calling.

Reimplements: FSMNode_Base::GetOrCreateNodeInstance

---

function CanEverCreateNodeInstance

inline virtual bool CanEverCreateNodeInstance() const override

If the node can at some point create a node instance.

Reimplements: FSMNode_Base::CanEverCreateNodeInstance

---

function GetDefaultNodeInstanceClass

virtual UClass * GetDefaultNodeInstanceClass() const override

The default node instance class. Each derived node class needs to implement.

Reimplements: FSMState_Base::GetDefaultNodeInstanceClass

---

function GetOwnerNode

virtual FSMNode_Base * GetOwnerNode() const override

The node directly owning this node. Should be a StateMachine.

Reimplements: FSMNode_Base::GetOwnerNode

---

function SetStartTime

virtual void SetStartTime(
    const FDateTime & InStartTime
) override

Set the local start time.

Reimplements: FSMState_Base::SetStartTime

---

function SetEndTime

virtual void SetEndTime(
    const FDateTime & InEndTime
) override

Set the local end time.

Reimplements: FSMState_Base::SetEndTime

---

function SetServerTimeInState

virtual void SetServerTimeInState(
    float InTime
) override

Set the time in state as recorded from the server.

Reimplements: FSMNode_Base::SetServerTimeInState

---

function IsStateMachineInEndState

bool IsStateMachineInEndState() const

If this state machine is in an end state or has no active states.

---

function HasStateMachineReachedEndStateForRun

inline bool HasStateMachineReachedEndStateForRun() const

If the state machine has reached an end state for its current run. This can be set when an active state's IsEndState() is true, or if the state machine has deactivated all states.

---

function AddState

void AddState(
    FSMState_Base * State
)

Add a state to this State Machine.

---

function AddTransition

void AddTransition(
    FSMTransition * Transition
)

Add a transition to this State Machine.

---

function AddInitialState

void AddInitialState(
    FSMState_Base * State
)

The first state to execute. Even with parallel states there is always a single root entry point.

---

function AddTemporaryInitialState

void AddTemporaryInitialState(
    FSMState_Base * State
)

These states will replace the initial state, but once started will be cleared.

Parameters:

State

A non null state will be added to the set as long as it exists within the state machine. A null value is ignored.

---

function ClearTemporaryInitialStates

void ClearTemporaryInitialStates(
    bool bRecursive =false
)

Removes all temporary initial states.

---

function SetFromTemporaryInitialStates

void SetFromTemporaryInitialStates()

Loads temporary states if not already loaded and start them.

---

function ContainsActiveState

bool ContainsActiveState(
    FSMState_Base * StateToCheck
) const

Checks if the given state is contained within the active states.

---

function HasActiveStates

bool HasActiveStates() const

Checks if there are any active states.

---

function HasTemporaryEntryStates

bool HasTemporaryEntryStates() const

Checks if there any temporary initial states set.

---

function GetSingleActiveState

FSMState_Base * GetSingleActiveState() const

The current state of this State Machine. In the event of multiple parallel states the first active state is returned.

---

function GetActiveStates

TArray< FSMState_Base * > GetActiveStates() const

Returns a copy of all active states specific to this FSM making it safe for iteration modification.

---

function GetAllNestedActiveStates

TArray< FSMState_Base * > GetAllNestedActiveStates() const

Return a list of all active states recursively searching nested state machines.

---

function GetAllNodes

TArray< FSMNode_Base * > GetAllNodes(
    const FGetNodeArgs & InArgs =FGetNodeArgs()
) const

Retrieve nodes of all types.

Parameters:

InArgs

Arguments to filter out nodes.

---

function GetAllNodes

TArray< FSMNode_Base * > GetAllNodes(
    bool bIncludeNested,
    bool bForwardToReference =false
) const

Deprecated:

Use GetAllNodes() that takes the FGetNodeArgs arguments instead. bForwardToReference is no longer supported.

---

function GetStates

const TArray< FSMState_Base * > & GetStates() const

Retrieve nodes of all state types.

---

function GetTransitions

const TArray< FSMTransition * > & GetTransitions() const

Retrieve nodes of only transitions.

---

function GetEntryStates

const TArray< FSMState_Base * > & GetEntryStates() const

Returns only the original entry states.

---

function GetInitialStates

TArray< FSMState_Base * > GetInitialStates() const

The entry state of this state machine. Returns either the temporary or default. Possible to be greater than 0 when loading from temporary parallel states.

---

function GetSingleInitialState

FSMState_Base * GetSingleInitialState() const

Returns either null or the first initial state. Only use this if you know the FSM doesn't have parallel states.

---

function GetSingleInitialTemporaryState

FSMState_Base * GetSingleInitialTemporaryState() const

Returns either null or the first initial temporary state. Only use this if you know the FSM doesn't have parallel states.

---

function GetAllNestedInitialTemporaryStates

TArray< FSMState_Base * > GetAllNestedInitialTemporaryStates() const

Returns all nested temporary states if they are set.

---

function FindState

FSMState_Base * FindState(
    const FGuid & StateGuid
) const

Linear search recursively through all states and state machines.

---

function SetNetworkedConditions

void SetNetworkedConditions(
    TScriptInterface< ISMStateMachineNetworkedInterface > InNetworkInterface,
    bool bEvaluateTransitions,
    bool bTakeTransitions,
    bool bCanExecuteStateLogic
)

Determine how to process transitions and states in different environments.

---

function ProcessStates

void ProcessStates(
    float DeltaSeconds,
    bool bForceTransitionEvaluationOnly =false,
    const FGuid & InCurrentRunGuid =FGuid(),
    const FStateScopingArgs & InStateScopingArgs =FStateScopingArgs()
)

Determine if the current state should be stopped or started or evaluate a transition.

Parameters:

DeltaSeconds

Time since last update.

bForceTransitionEvaluationOnly

The update (Tick) logic for a state won't be called unless the state is ending and bAlwaysUpdate is checked. Start and End may still be called.

InCurrentRunGuid

A guid unique to this call stack. Leave empty, for internal use.

InStateScopingArgs

Limit state processing to select states.

---

function ProcessTransition

bool ProcessTransition(
    FSMTransition * Transition,
    FSMState_Base * SourceState,
    FSMState_Base * DestinationState,
    const FSMTransitionTransaction * Transaction,
    float DeltaSeconds,
    FDateTime * CurrentTime =nullptr
)

Attempt to take a transition. Does not evaluate the transition. Returns true if successful.

Parameters:

Transition

The transition to process.

SourceState

The original state to transition from.

DestinationState

the final state to transition to.

Transaction

A network transaction if one exists. May be null.

DeltaSeconds

The time in seconds since the last update.

CurrentTime

The current UTC time. Only utilized in networked environments for recording time stamps.

---

function EvaluateAndTakeTransitionChain

bool EvaluateAndTakeTransitionChain(
    FSMTransition * InFirstTransition
)

Evaluate an entire transition chain discovering the path to take. If an entire chain passes then switch to the destination state.

A transition chain is the first path that evaluates to true between two states, consisting of all transitions and conduits that are configured to eval with transitions.

This method fails if the state machine isn't state change authoritative. The destination state won't become active if this state machine doesn't have local state change authority.

If the method passes each transition taken will be replicated in order.

Parameters:

InFirstTransition

The transition struct, which should be the first part of a transition chain.

Return: True if the chain succeeded evaluation.

---

function TakeTransitionChain

bool TakeTransitionChain(
    const TArray< FSMTransition * > & InTransitionChain
)

Take a transition chain. Does not evaluate, but adheres to all normal state change behavior.

Parameters:

InTransitionChain

The transition chain to take.

Return: True if taken.

---

function TryStartState

bool TryStartState(
    FSMState_Base * InState,
    bool * bOutSafeToCheckTransitions =nullptr
)

Try starting the given state.

Parameters:

InState

The state to start.

bOutSafeToCheckTransitions

[Out] If it is safe to check transitions on this state this frame.

Return: True if the state was started, false if it was already started or cannot start.

---

function TryTakeTransitionChain

bool TryTakeTransitionChain(
    const TArray< FSMTransition * > & InTransitionChain,
    float DeltaSeconds,
    bool bStateJustStarted =false,
    FSMState_Base ** OutDestinationState =nullptr
)

Try taking the given transition chain to the end destination state.

Parameters:

InTransitionChain

A single transition, or multiple transitions with conduits.

DeltaSeconds

Delta seconds to apply to ProcessTransition.

bStateJustStarted

If the source state has started this frame.

OutDestinationState

[Out] The destination state at the end of chain, only set if the transition chain was taken.

Return: True if the transition chain was taken, false if not.

---

function CanProcessExternalTransition

bool CanProcessExternalTransition() const

External callers should check this before calling ProcessTransition().

---

function IsWaitingForUpdate

inline bool IsWaitingForUpdate() const

State Machine is currently waiting for a transition update from the server.

---

function SetReuseCurrentState

void SetReuseCurrentState(
    bool bValue,
    bool bOnlyWhenNotInEndState
)

When true the current state is reused on exit/reentry. When false the current state is cleared on end and the initial state used on reentry.

---

function CanReuseCurrentState

bool CanReuseCurrentState() const

Is the current state reused or reset on exit/reentry.

---

function SetClassReference

void SetClassReference(
    UClass * ClassReference
)

---

function GetClassReference

inline UClass * GetClassReference() const

---

function SetInstanceReference

void SetInstanceReference(
    USMInstance * InstanceReference
)

---

function GetInstanceReference

inline USMInstance * GetInstanceReference() const

---

function SetReferencedTemplateName

void SetReferencedTemplateName(
    const FName & Name
)

---

function GetReferencedTemplateName

inline const FName & GetReferencedTemplateName() const

---

function SetReferencedBy

void SetReferencedBy(
    USMInstance * FromInstance,
    FSMStateMachine * FromStateMachine
)

---

function GetReferencedByInstance

inline USMInstance * GetReferencedByInstance() const

The instance referencing this state machine.

---

function GetReferencedByStateMachine

inline FSMStateMachine * GetReferencedByStateMachine() const

The exact state machine referencing this, if any.

---

function SetDynamicReferenceVariableName

inline void SetDynamicReferenceVariableName(
    const FName & InVariableName
)

Set a variable name of the owning SMInstance to use for a dynamic class lookup.

---

function GetDynamicReferenceVariableName

inline const FName & GetDynamicReferenceVariableName() const

Get a variable name to use with the owning SMInstance for dynamic class lookup.

---

function IsDynamicReference

inline bool IsDynamicReference() const

If this is a dynamic state machine reference.

---

function IsNetworked

inline bool IsNetworked() const

True only if this FSM is networked.

---

function TryGetNetworkInterfaceIfNetworked

ISMStateMachineNetworkedInterface * TryGetNetworkInterfaceIfNetworked() const

Find the network interface if one is assigned and active.

---

function GetStateNameMap

const TMap< FString, FSMState_Base * > & GetStateNameMap() const

All contained states mapped out by their name, limited to this FSM scope.

---

function AddActiveState

void AddActiveState(
    FSMState_Base * State
)

Forcibly add an active state.

Parameters:

State

The state to add to the active list.

---

function RemoveActiveState

void RemoveActiveState(
    FSMState_Base * State
)

Forcibly remove an active state.

Parameters:

State

The state to remove from the active list.

---

function ResetGeneratedValues

virtual void ResetGeneratedValues() override

Reset any values set from state machine generation.

Reimplements: FSMState_Base::ResetGeneratedValues

---

Protected Functions Documentation

function InitializeFunctionHandlers

virtual void InitializeFunctionHandlers() override

Map the FunctionHandler pointer. Must be implemented per child struct!

Reimplements: FSMNode_Base::InitializeFunctionHandlers

---

function NotifyInstanceStateHasStarted

virtual void NotifyInstanceStateHasStarted() override

Call the owning instance letting it know this state has started.

Reimplements: FSMState_Base::NotifyInstanceStateHasStarted

---

function SetCurrentState

void SetCurrentState(
    FSMState_Base * ToState,
    FSMState_Base * FromState,
    FSMState_Base * SourceState =nullptr
)

Switches the current state and notifies the owning instance.

Parameters:

ToState

The state we should be switching to. May be null.

FromState

The state we are switching from. If not null it will be removed from the active list if bStayActiveOnStateChange is false.

SourceState

The original source state we are transitioning from. This can be different from the FromState if transition conduits are involved.

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function TryNotifyEndStateReached

void TryNotifyEndStateReached()

Check if an end state has been reached, fire notifications, and traverse any owners that are waiting for an end state.

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Public Attributes Documentation

variable bHasAdditionalLogic

uint8 bHasAdditionalLogic;

If this has additional logic associated with it.

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variable bReuseCurrentState

uint8 bReuseCurrentState;

The current state is not cleared on end and will be resumed on start.

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variable bOnlyReuseIfNotEndState

uint8 bOnlyReuseIfNotEndState;

Don't reuse if the state machine is in an end state.

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variable bAllowIndependentTick

uint8 bAllowIndependentTick;

Allows the state machine reference to tick on its own.

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variable bCallReferenceTickOnManualUpdate

uint8 bCallReferenceTickOnManualUpdate;

Notifies instance to call tick on manual update. Only valid for references.

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variable bWaitForEndState

uint8 bWaitForEndState;

Wait for an end state to be hit before evaluating transitions or being considered an end state itself.

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Private Attributes Documentation

variable NetworkedInterface

TScriptInterface< ISMStateMachineNetworkedInterface > NetworkedInterface;

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variable States

TArray< FSMState_Base * > States;

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variable Transitions

TArray< FSMTransition * > Transitions;

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variable EntryStates

TArray< FSMState_Base * > EntryStates;

The default root entry point.

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variable TemporaryEntryStates

TArray< FSMState_Base * > TemporaryEntryStates;

Entry states that are temporary and used for loading purposes.

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variable ActiveStates

TArray< FSMState_Base * > ActiveStates;

In most cases this should be of size 0 or 1. Greater than 1 implies the sm is configured for multiple active states. Array container needed for exact order when adding parallel states. O(n) operations should be acceptable for average number of active states and only on state changes.

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variable StateNameMap

TMap< FString, FSMState_Base * > StateNameMap;

All contained states, mapped by their name.

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variable ProcessingStates

TMap< FGuid, TSet< FSMState_Base * > > ProcessingStates;

Keeps track of states currently processing for the given FSM scope. Helps with possible infinite recursion when using multiple states that can re-enter each other.

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variable ReferencedStateMachineClass

TObjectPtr< UClass > ReferencedStateMachineClass;

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variable ReferencedTemplateName

FName ReferencedTemplateName;

The name of a template archetype to use when constructing a reference. This allows default values be passed into the reference.

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variable DynamicStateMachineReferenceVariable

FName DynamicStateMachineReferenceVariable;

The name of a variable stored on the owning SMInstance that should be used to find the class for this reference.

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variable ReferencedStateMachine

TObjectPtr< USMInstance > ReferencedStateMachine;

This state machine is referencing an instance.

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variable IsReferencedByInstance

TObjectPtr< USMInstance > IsReferencedByInstance;

This state machine is being referenced from an instance.

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variable IsReferencedByStateMachine

FSMStateMachine * IsReferencedByStateMachine;

The state machine referencing this state machine, if any.

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variable TimeSpentWaitingForUpdate

float TimeSpentWaitingForUpdate;

Current time spent waiting for an update.

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variable bWaitingForTransitionUpdate

uint8 bWaitingForTransitionUpdate;

Is currently waiting for an update.

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variable bCanEvaluateTransitions

uint8 bCanEvaluateTransitions;

Can this instance even evaluate transitions.

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variable bCanTakeTransitions

uint8 bCanTakeTransitions;

Once evaluated can this instance take the transition.

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variable bHasReachedEndStateForRun

uint8 bHasReachedEndStateForRun;

True if the state machine has reached an end state at least once and is reset on node initialize.

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