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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(USMInstance * 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
virtual bool GetValidTransition(TArray< TArray< FSMTransition * > > & OutTransitions) override
void CreateAllNodeInstances()
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 TSharedPtr< FSMNodeRuntimeData > CreateRuntimeData() const override
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 HasUpdated() const
virtual bool IsConduit() const
bool IsRootNode() const
float GetActiveTime() const
void SetCanExecuteLogic(bool bValue)
bool CanExecuteLogic() const
virtual bool CanExecuteGraphProperties(ESMGraphPropertyEvalFlags OnEvent, const USMStateInstance_Base * ForTemplate, ESMGraphPropertyDirection InDirection) 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

Friends inherited from FSMState_Base

Name
struct FSMTransition(FSMTransition )

Public Classes inherited from FSMNode_Base

Name
struct FFilterGraphPropertyArgs

Public Functions inherited from FSMNode_Base

Name
FSMNode_FunctionHandlers * GetFunctionHandlers() const
virtual void UpdateReadStates()
FSMNode_Base()
virtual ~FSMNode_Base() =default
FSMNode_Base(const FSMNode_Base & Node) =default
FSMNode_Base & operator=(const FSMNode_Base & Node)
const TSharedPtr< FSMNodeRuntimeData > & GetRuntimeData() const
TSharedPtr< T > GetRuntimeDataAs() const
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
USMNodeInstance * GetNodeInStack(const FGuid & InTemplateGuid) 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(ESMGraphPropertyEvalFlags OnEvent, const class USMStateInstance_Base * ForTemplate, ESMGraphPropertyDirection InDirection) const
virtual bool TryExecuteGraphProperties(ESMGraphPropertyEvalFlags OnEvent, ESMGraphPropertyDirection InDirection)
void TryExecuteGraphProperties(ESMGraphPropertyEvalFlags OnEvent)
void ExecuteGraphProperties(USMNodeInstance * ForNodeInstance, const FGuid * ForTemplateGuid)
void ExecuteGraphProperties(const FFilterGraphPropertyArgs & InArgs)
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()
void TriggerDebugBreakpoint()
FName GetNodeGuidPropertyName()
FName GetPathGuidPropertyName()

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
FVector2D NodePosition
float TimeInState
int32 DuplicateId
uint8 bIsInEndState
uint8 bHasUpdated
uint8 bHasInputEvents

Protected Attributes inherited from FSMNode_Base

Name
FGuid Guid
FGuid OwnerGuid
FGuid PathGuid
FString NodeName
FName TemplateName
TArray< FName > StackTemplateNames
TArray< TObjectPtr< USMNodeInstance > > StackNodeInstances
TObjectPtr< USMInstance > OwningInstance
TObjectPtr< USMNodeInstance > NodeInstance
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(
    USMInstance * Instance
) override

Initializes various properties and associate the node with its owning state machine instance.

Parameters:

Instance
The state machine instance used to initialize the node.

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: FSMState_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 GetValidTransition¶

virtual bool GetValidTransition(
    TArray< TArray< FSMTransition * > > & OutTransitions
) override

Runs through the transitions executing their graphs until a result is found. Builds an ordered list of transitions to take.

Parameters:

OutTransitions
Found transitions. 2D Array of valid paths. If the total size is more than one that means these transitions are leading to parallel states. if each path is more than one that means there are transition conduits involved.

Return: True if a valid path is found, false otherwise.

Reimplements: FSMState_Base::GetValidTransition

function CreateAllNodeInstances¶

void CreateAllNodeInstances()

Create node instances for all applicable nodes.

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 CreateRuntimeData¶

inline virtual TSharedPtr< FSMNodeRuntimeData > CreateRuntimeData() const override

Reimplements: FSMState_Base::CreateRuntimeData

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.

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.

Public Attributes Documentation¶

variable bHasAdditionalLogic¶

uint8 bHasAdditionalLogic;

If this has additional logic associated with it.

variable bReuseCurrentState¶

uint8 bReuseCurrentState;

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

variable bOnlyReuseIfNotEndState¶

uint8 bOnlyReuseIfNotEndState;

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

variable bAllowIndependentTick¶

uint8 bAllowIndependentTick;

Allows the state machine reference to tick on its own.

variable bCallReferenceTickOnManualUpdate¶

uint8 bCallReferenceTickOnManualUpdate;

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

variable bWaitForEndState¶

uint8 bWaitForEndState;

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

Private Attributes Documentation¶

variable NetworkedInterface¶

TScriptInterface< ISMStateMachineNetworkedInterface > NetworkedInterface;

variable ReferencedStateMachineClass¶

TObjectPtr< UClass > ReferencedStateMachineClass;

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.

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.

variable ReferencedStateMachine¶

TObjectPtr< USMInstance > ReferencedStateMachine;

This state machine is referencing an instance.

variable IsReferencedByInstance¶

TObjectPtr< USMInstance > IsReferencedByInstance;

This state machine is being referenced from an instance.