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UnrealEngine/Engine/Plugins/Runtime/StateTree/Source/StateTreeEditorModule/Public/StateTreeState.h
2025-05-18 13:04:45 +08:00

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// Copyright Epic Games, Inc. All Rights Reserved.
#pragma once
#include "IStateTreeSchemaProvider.h"
#include "StateTreeNodeBase.h"
#include "StateTreeEditorNode.h"
#include "StateTreeEditorTypes.h"
#include "StateTreeEvents.h"
#include "StateTreeState.generated.h"
class UStateTreeState;
class UStateTree;
/**
* Editor representation of an event description.
*/
USTRUCT()
struct FStateTreeEventDesc
{
GENERATED_BODY()
FStateTreeEventDesc() = default;
FStateTreeEventDesc(FGameplayTag InTag)
: Tag(InTag)
{}
/** Event Tag. */
UPROPERTY(EditDefaultsOnly, Category = "Event")
FGameplayTag Tag;
/** Event Payload Struct. */
UPROPERTY(EditDefaultsOnly, Category = "Event")
TObjectPtr<const UScriptStruct> PayloadStruct;
/** If set to true, the event is consumed (later state selection cannot react to it) if state selection can be made. */
UPROPERTY(EditDefaultsOnly, Category = "Event")
bool bConsumeEventOnSelect = true;
bool IsValid() const
{
return Tag.IsValid() || PayloadStruct;
}
FStateTreeEvent& GetTemporaryEvent()
{
TemporaryEvent.Tag = Tag;
TemporaryEvent.Payload = FInstancedStruct(PayloadStruct);
return TemporaryEvent;
}
bool operator==(const FStateTreeEventDesc& Other) const
{
return Tag == Other.Tag && PayloadStruct == Other.PayloadStruct;
}
private:
/** Temporary event used as a source value in bindings. */
UPROPERTY(Transient)
FStateTreeEvent TemporaryEvent;
};
/**
* StateTree's internal delegate listener used exclusively in transitions.
*/
USTRUCT()
struct FStateTreeTransitionDelegateListener
{
GENERATED_BODY()
};
/**
* Editor representation of a transition in StateTree
*/
USTRUCT()
struct STATETREEEDITORMODULE_API FStateTreeTransition
{
GENERATED_BODY()
// Macro needed to avoid deprecation errors with members being copied or created.
PRAGMA_DISABLE_DEPRECATION_WARNINGS
FStateTreeTransition() = default;
FStateTreeTransition(const EStateTreeTransitionTrigger InTrigger, const EStateTreeTransitionType InType, const UStateTreeState* InState = nullptr);
FStateTreeTransition(const EStateTreeTransitionTrigger InTrigger, const FGameplayTag InEventTag, const EStateTreeTransitionType InType, const UStateTreeState* InState = nullptr);
FStateTreeTransition(const FStateTreeTransition&) = default;
FStateTreeTransition(FStateTreeTransition&&) = default;
FStateTreeTransition& operator=(const FStateTreeTransition&) = default;
FStateTreeTransition& operator=(FStateTreeTransition&&) = default;
PRAGMA_ENABLE_DEPRECATION_WARNINGS
template<typename T, typename... TArgs>
TStateTreeEditorNode<T>& AddCondition(TArgs&&... InArgs)
{
FStateTreeEditorNode& CondNode = Conditions.AddDefaulted_GetRef();
CondNode.ID = FGuid::NewGuid();
CondNode.Node.InitializeAs<T>(Forward<TArgs>(InArgs)...);
const FStateTreeNodeBase& Node = CondNode.Node.GetMutable<FStateTreeNodeBase>();
if (const UScriptStruct* InstanceType = Cast<const UScriptStruct>(Node.GetInstanceDataType()))
{
CondNode.Instance.InitializeAs(InstanceType);
}
return static_cast<TStateTreeEditorNode<T>&>(CondNode);
}
FGuid GetEventID() const
{
return FGuid::Combine(ID, FGuid::NewDeterministicGuid(TEXT("Event")));
}
void PostSerialize(const FArchive& Ar);
/** When to try trigger the transition. */
UPROPERTY(EditDefaultsOnly, Category = "Transition")
EStateTreeTransitionTrigger Trigger = EStateTreeTransitionTrigger::OnStateCompleted;
/** Defines the event required to be present during state selection for the transition to trigger. */
UPROPERTY(EditDefaultsOnly, Category = "Transition", DisplayName = "Required Event")
FStateTreeEventDesc RequiredEvent;
/** Transition target state. */
UPROPERTY(EditDefaultsOnly, Category = "Transition", meta=(DisplayName="Transition To"))
FStateTreeStateLink State;
UPROPERTY(EditDefaultsOnly, Category = "Transition")
FGuid ID;
/** Listener to the selected delegate dispatcher. */
UPROPERTY(EditDefaultsOnly, Category = "Transition", DisplayName = "Delegate")
FStateTreeTransitionDelegateListener DelegateListener;
/**
* Transition priority when multiple transitions happen at the same time.
* During transition handling, the transitions are visited from leaf to root.
* The first visited transition, of highest priority, that leads to a state selection, will be activated.
*/
UPROPERTY(EditDefaultsOnly, Category = "Transition")
EStateTreeTransitionPriority Priority = EStateTreeTransitionPriority::Normal;
/** Delay the triggering of the transition. */
UPROPERTY(EditDefaultsOnly, Category = "Transition")
bool bDelayTransition = false;
/** Transition delay duration in seconds. */
UPROPERTY(EditDefaultsOnly, Category = "Transition", meta = (EditCondition = "bDelayTransition", UIMin = "0", ClampMin = "0", UIMax = "25", ClampMax = "25", ForceUnits="s"))
float DelayDuration = 0.0f;
/** Transition delay random variance in seconds. */
UPROPERTY(EditDefaultsOnly, Category = "Transition", meta = (EditCondition = "bDelayTransition", UIMin = "0", ClampMin = "0", UIMax = "25", ClampMax = "25", ForceUnits="s"))
float DelayRandomVariance = 0.0f;
/** Expression of conditions that need to evaluate to true to allow transition to be triggered. */
UPROPERTY(EditDefaultsOnly, Category = "Transition", meta = (BaseStruct = "/Script/StateTreeModule.StateTreeConditionBase", BaseClass = "/Script/StateTreeModule.StateTreeConditionBlueprintBase"))
TArray<FStateTreeEditorNode> Conditions;
/** True if the Transition is Enabled (i.e. not explicitly disabled in the asset). */
UPROPERTY(EditDefaultsOnly, Category = "Debug")
bool bTransitionEnabled = true;
#if WITH_EDITORONLY_DATA
UE_DEPRECATED(5.5, "Use RequiredEvent.Tag instead.")
UPROPERTY()
FGameplayTag EventTag_DEPRECATED;
#endif // WITH_EDITORONLY_DATA
};
template<>
struct TStructOpsTypeTraits<FStateTreeTransition> : public TStructOpsTypeTraitsBase2<FStateTreeTransition>
{
enum
{
WithPostSerialize = true,
};
};
USTRUCT()
struct STATETREEEDITORMODULE_API FStateTreeStateParameters
{
GENERATED_BODY()
void ResetParametersAndOverrides()
{
// Reset just the parameters, keep the bFixedLayout intact.
Parameters.Reset();
PropertyOverrides.Reset();
}
/** Removes overrides that do appear in Parameters. */
void RemoveUnusedOverrides();
UPROPERTY(EditDefaultsOnly, Category = Parameters)
FInstancedPropertyBag Parameters;
/** Overrides for parameters. */
UPROPERTY()
TArray<FGuid> PropertyOverrides;
UPROPERTY(EditDefaultsOnly, Category = Parameters)
bool bFixedLayout = false;
UPROPERTY(EditDefaultsOnly, Category = Parameters, meta = (IgnoreForMemberInitializationTest))
FGuid ID;
};
/**
* Editor representation of a state in StateTree
*/
UCLASS(BlueprintType, EditInlineNew, CollapseCategories)
class STATETREEEDITORMODULE_API UStateTreeState : public UObject, public IStateTreeSchemaProvider
{
GENERATED_BODY()
public:
UStateTreeState(const FObjectInitializer& ObjectInitializer);
virtual ~UStateTreeState() override;
virtual void PostInitProperties() override;
virtual void PreEditChange(FEditPropertyChain& PropertyAboutToChange) override;
virtual void PostEditChangeChainProperty(FPropertyChangedChainEvent& PropertyChangedEvent) override;
virtual void PostLoad() override;;
void UpdateParametersFromLinkedSubtree();
void OnTreeCompiled(const UStateTree& StateTree);
const UStateTreeState* GetRootState() const;
const UStateTreeState* GetNextSiblingState() const;
const UStateTreeState* GetNextSelectableSiblingState() const;
/** @return the path of the state as string. */
FString GetPath() const;
/** @return true if the property of specified ID is overridden. */
bool IsParametersPropertyOverridden(const FGuid PropertyID) const
{
return Parameters.PropertyOverrides.Contains(PropertyID);
}
/** Sets the override status of specified property by ID. */
void SetParametersPropertyOverridden(const FGuid PropertyID, const bool bIsOverridden);
/** @returns Default parameters from linked state or asset). */
const FInstancedPropertyBag* GetDefaultParameters() const;
//~ StateTree Builder API
/** @return state link to this state. */
FStateTreeStateLink GetLinkToState() const;
/** Adds child state with specified name. */
UStateTreeState& AddChildState(const FName ChildName, const EStateTreeStateType StateType = EStateTreeStateType::State)
{
UStateTreeState* ChildState = NewObject<UStateTreeState>(this, FName(), RF_Transactional);
check(ChildState);
ChildState->Name = ChildName;
ChildState->Parent = this;
ChildState->Type = StateType;
Children.Add(ChildState);
return *ChildState;
}
/**
* Adds enter condition of specified type.
* @return reference to the new condition.
*/
template<typename T, typename... TArgs>
TStateTreeEditorNode<T>& AddEnterCondition(TArgs&&... InArgs)
{
FStateTreeEditorNode& CondNode = EnterConditions.AddDefaulted_GetRef();
CondNode.ID = FGuid::NewGuid();
CondNode.Node.InitializeAs<T>(Forward<TArgs>(InArgs)...);
const FStateTreeNodeBase& Node = CondNode.Node.GetMutable<FStateTreeNodeBase>();
if (const UScriptStruct* InstanceType = Cast<const UScriptStruct>(Node.GetInstanceDataType()))
{
CondNode.Instance.InitializeAs(InstanceType);
}
return static_cast<TStateTreeEditorNode<T>&>(CondNode);
}
/**
* Adds Task of specified type.
* @return reference to the new Task.
*/
template<typename T, typename... TArgs>
TStateTreeEditorNode<T>& AddTask(TArgs&&... InArgs)
{
FStateTreeEditorNode& TaskItem = Tasks.AddDefaulted_GetRef();
TaskItem.ID = FGuid::NewGuid();
TaskItem.Node.InitializeAs<T>(Forward<TArgs>(InArgs)...);
const FStateTreeNodeBase& Node = TaskItem.Node.GetMutable<FStateTreeNodeBase>();
if (const UScriptStruct* InstanceType = Cast<const UScriptStruct>(Node.GetInstanceDataType()))
{
TaskItem.Instance.InitializeAs(InstanceType);
}
return static_cast<TStateTreeEditorNode<T>&>(TaskItem);
}
/** Sets linked state and updates parameters to match the linked state. */
void SetLinkedState(FStateTreeStateLink InStateLink);
/** Sets linked asset and updates parameters to match the linked asset. */
void SetLinkedStateAsset(UStateTree* InLinkedAsset);
/**
* Adds Transition.
* @return reference to the new Transition.
*/
FStateTreeTransition& AddTransition(const EStateTreeTransitionTrigger InTrigger, const EStateTreeTransitionType InType, const UStateTreeState* InState = nullptr)
{
FStateTreeTransition& Transition = Transitions.Emplace_GetRef(InTrigger, InType, InState);
Transition.ID = FGuid::NewGuid();
return Transition;
}
FStateTreeTransition& AddTransition(const EStateTreeTransitionTrigger InTrigger, const FGameplayTag InEventTag, const EStateTreeTransitionType InType, const UStateTreeState* InState = nullptr)
{
FStateTreeTransition& Transition = Transitions.Emplace_GetRef(InTrigger, InEventTag, InType, InState);
Transition.ID = FGuid::NewGuid();
return Transition;
}
FGuid GetEventID() const
{
return FGuid::Combine(ID, FGuid::NewDeterministicGuid(TEXT("Event")));
}
//~ IStateTreeSchemaProvider API
/** @return Class of schema used by the state tree containing this state. */
virtual TSubclassOf<UStateTreeSchema> GetSchema() const override;
//~IStateTreeSchemaProvider API
//~ Note: these properties are customized out in FStateTreeStateDetails, adding a new property might require to adjust the customization.
/** Display name of the State */
UPROPERTY(EditDefaultsOnly, Category = "State")
FName Name;
/** Description of the State */
UPROPERTY(EditDefaultsOnly, Category = "State", meta=(MultiLine))
FString Description;
/** GameplayTag describing the State */
UPROPERTY(EditDefaultsOnly, Category = "State")
FGameplayTag Tag;
/** Display color of the State */
UPROPERTY(EditDefaultsOnly, Category = "State", DisplayName = "Color")
FStateTreeEditorColorRef ColorRef;
/** Type the State, allows e.g. states to be linked to other States. */
UPROPERTY(EditDefaultsOnly, Category = "State")
EStateTreeStateType Type = EStateTreeStateType::State;
/** How to treat child states when this State is selected. */
UPROPERTY(EditDefaultsOnly, Category = "State")
EStateTreeStateSelectionBehavior SelectionBehavior = EStateTreeStateSelectionBehavior::TrySelectChildrenInOrder;
/** How tasks will complete the state. Only tasks that are considered for completion can complete the state. */
UPROPERTY(EditDefaultsOnly, Category = "State")
EStateTreeTaskCompletionType TasksCompletion = EStateTreeTaskCompletionType::Any;
/** Subtree to run as extension of this State. */
UPROPERTY(EditDefaultsOnly, Category = "State", Meta=(DirectStatesOnly, SubtreesOnly))
FStateTreeStateLink LinkedSubtree;
/** Another State Tree asset to run as extension of this State. */
UPROPERTY(EditDefaultsOnly, Category = "State")
TObjectPtr<UStateTree> LinkedAsset = nullptr;
/**
* Tick rate in seconds the state tasks and transitions should tick.
* If set the state cannot sleep.
* If set all the other states (children or parents) will also tick at that rate.
* If more than one active states has a custom tick rate then the smallest custom tick rate wins.
* If not set, the state will tick every frame unless the state tree is allowed to sleep.
*/
UPROPERTY(EditDefaultsOnly, Category = "State", meta = (EditCondition = "bHasCustomTickRate", ClampMin = 0.0f))
float CustomTickRate = 0.0f;
/** Activate the CustomTickRate. */
UPROPERTY(EditDefaultsOnly, Category = "State", meta=(InlineEditConditionToggle))
bool bHasCustomTickRate = false;
/** Parameters of this state. If the state is linked to another state or asset, the parameters are for the linked state. */
UPROPERTY(EditDefaultsOnly, Category = "State")
FStateTreeStateParameters Parameters;
/** Should state's required event and enter conditions be evaluated when transition leads directly to it's child. */
UPROPERTY(EditDefaultsOnly, Category = "Enter Conditions")
bool bCheckPrerequisitesWhenActivatingChildDirectly = true;
UPROPERTY(EditDefaultsOnly, Category = "Enter Conditions", meta=(InlineEditConditionToggle))
bool bHasRequiredEventToEnter = false;
/** Defines the event required to be present during state selection for the state to be selected. */
UPROPERTY(EditDefaultsOnly, Category = "Enter Conditions", meta = (EditCondition = "bHasRequiredEventToEnter"))
FStateTreeEventDesc RequiredEventToEnter;
/** Weight used to scale the normalized final utility score for this state */
UPROPERTY(EditDefaultsOnly, Category = "Utility", meta=(ClampMin=0))
float Weight = 1.f;
/** Expression of enter conditions that needs to evaluate true to allow the state to be selected. */
UPROPERTY(EditDefaultsOnly, Category = "Enter Conditions", meta = (BaseStruct = "/Script/StateTreeModule.StateTreeConditionBase", BaseClass = "/Script/StateTreeModule.StateTreeConditionBlueprintBase"))
TArray<FStateTreeEditorNode> EnterConditions;
UPROPERTY(EditDefaultsOnly, Category = "Tasks", meta = (BaseStruct = "/Script/StateTreeModule.StateTreeTaskBase", BaseClass = "/Script/StateTreeModule.StateTreeTaskBlueprintBase"))
TArray<FStateTreeEditorNode> Tasks;
/** Expression of enter conditions that needs to evaluate true to allow the state to be selected. */
UPROPERTY(EditDefaultsOnly, Category = "Utility", meta = (BaseStruct = "/Script/StateTreeModule.StateTreeConsiderationBase", BaseClass = "/Script/StateTreeModule.StateTreeConsiderationBlueprintBase"))
TArray<FStateTreeEditorNode> Considerations;
// Single item used when schema calls for single task per state.
UPROPERTY(EditDefaultsOnly, Category = "Task", meta = (BaseStruct = "/Script/StateTreeModule.StateTreeTaskBase", BaseClass = "/Script/StateTreeModule.StateTreeTaskBlueprintBase"))
FStateTreeEditorNode SingleTask;
UPROPERTY(EditDefaultsOnly, Category = "Transitions")
TArray<FStateTreeTransition> Transitions;
UPROPERTY(Instanced)
TArray<TObjectPtr<UStateTreeState>> Children;
UPROPERTY(EditDefaultsOnly, Category = "State", meta = (IgnoreForMemberInitializationTest))
FGuid ID;
UPROPERTY(meta = (ExcludeFromHash))
bool bExpanded = true;
UPROPERTY(EditDefaultsOnly, Category = "State")
bool bEnabled = true;
UPROPERTY(meta = (ExcludeFromHash))
TObjectPtr<UStateTreeState> Parent = nullptr;
};