UnrealEngineUWP/Engine/Plugins/Runtime/StateTree/Source/StateTreeModule/Private/Blueprint/StateTreeNodeBlueprintBase.cpp

// Copyright Epic Games, Inc. All Rights Reserved.

#include "Blueprint/StateTreeNodeBlueprintBase.h"
#include "AIController.h"
#include "StateTreeExecutionContext.h"
#include "VisualLogger/VisualLogger.h"
#include "StateTreePropertyRef.h"
#include "StateTreePropertyRefHelpers.h"

#include UE_INLINE_GENERATED_CPP_BY_NAME(StateTreeNodeBlueprintBase)

UWorld* UStateTreeNodeBlueprintBase::GetWorld() const
{
	// The items are duplicated as the State Tree execution context as outer, so this should be essentially the same as GetWorld() on StateTree context.
	// The CDO is used by the BP editor to check for certain functionality, make it return nullptr so that the GetWorld() passes as overridden. 
	if (!HasAnyFlags(RF_ClassDefaultObject))
	{
		if (CachedOwner != nullptr)
		{
			return CachedOwner->GetWorld();
		}
		if (UObject* Outer = GetOuter())
		{
			return Outer->GetWorld();
		}
	}
	
	return nullptr;
}

AActor* UStateTreeNodeBlueprintBase::GetOwnerActor(const FStateTreeExecutionContext& Context) const
{
	if (const AAIController* Controller = Cast<AAIController>(Context.GetOwner()))
	{
		return Controller->GetPawn();
	}
	
	return Cast<AActor>(Context.GetOwner());
}

void UStateTreeNodeBlueprintBase::SetCachedInstanceDataFromContext(const FStateTreeExecutionContext& Context) const
{
	if (FStateTreeInstanceData* InstanceData = Context.GetMutableInstanceData())
	{
		WeakInstanceStorage = InstanceData->GetWeakMutableStorage();
	}
	CachedState = Context.GetCurrentlyProcessedState();
	CachedOwner = Context.GetOwner();

	const FStateTreeExecutionFrame* CurrentlyProcessedFrame = Context.GetCurrentlyProcessedFrame();
	check(CurrentlyProcessedFrame);

	CachedFrameStateTree = CurrentlyProcessedFrame->StateTree;
	CachedFrameRootState = CurrentlyProcessedFrame->RootState;
}

void UStateTreeNodeBlueprintBase::ClearCachedInstanceData() const
{
	WeakInstanceStorage = nullptr;
	CachedState = FStateTreeStateHandle::Invalid;
	CachedOwner = nullptr;
	CachedFrameStateTree = nullptr;
	CachedFrameRootState = FStateTreeStateHandle::Invalid;
}

void* UStateTreeNodeBlueprintBase::GetMutablePtrToProperty(const FStateTreeBlueprintPropertyRef& PropertyRef, FProperty*& OutSourceProperty) const
{
	TSharedPtr<FStateTreeInstanceStorage> InstanceStorage = WeakInstanceStorage.Pin();
	if (InstanceStorage == nullptr)
	{
		UE_VLOG_UELOG(this, LogStateTree, Error, TEXT("Trying to GetMutablePtrToProperty while node is not active."));
		return nullptr;
	}

	check(CachedFrameStateTree && CachedFrameRootState.IsValid());

	TConstArrayView<FStateTreeExecutionFrame> ActiveFrames = InstanceStorage->GetExecutionState().ActiveFrames;

	const int32 CurrentFrameIndex = ActiveFrames.IndexOfByPredicate([this](const FStateTreeExecutionFrame& Frame)
	{
		return Frame.StateTree == CachedFrameStateTree && Frame.RootState == CachedFrameRootState;
	});

	check(CurrentFrameIndex != INDEX_NONE);
	const FStateTreeExecutionFrame& CurrentFrame = ActiveFrames[CurrentFrameIndex];

	const FStateTreeExecutionFrame* CurrentParentFrame = nullptr;
	if (CurrentFrameIndex > 0)
	{
		CurrentParentFrame = &ActiveFrames[CurrentFrameIndex - 1];
	}

	const FProperty* SourceProperty = nullptr;
	void* PropertyAddress = UE::StateTree::PropertyRefHelpers::GetMutablePtrToProperty<void>(PropertyRef, *InstanceStorage, CurrentFrame, CurrentParentFrame, &SourceProperty);
	if (PropertyAddress && UE::StateTree::PropertyRefHelpers::IsBlueprintPropertyRefCompatibleWithProperty(*SourceProperty, &PropertyRef))
	{
		OutSourceProperty = const_cast<FProperty*>(SourceProperty);
		return PropertyAddress;
	}

	OutSourceProperty = nullptr;
	return nullptr;
}

void UStateTreeNodeBlueprintBase::SendEvent(const FStateTreeEvent& Event)
{
	TSharedPtr<FStateTreeInstanceStorage> InstanceStorage = WeakInstanceStorage.Pin();

	if (InstanceStorage == nullptr || CachedOwner == nullptr)
	{
		UE_VLOG_UELOG(this, LogStateTree, Error, TEXT("Trying to call SendEvent() while node is not active. Use SendEvent() on UStateTreeComponent instead for sending signals externally."));
		return;
	}
	InstanceStorage->GetMutableEventQueue().SendEvent(CachedOwner, Event.Tag, Event.Payload, Event.Origin);
}

void UStateTreeNodeBlueprintBase::RequestTransition(const FStateTreeStateLink& TargetState, const EStateTreeTransitionPriority Priority)
{
	TSharedPtr<FStateTreeInstanceStorage> InstanceStorage = WeakInstanceStorage.Pin();

	if (InstanceStorage == nullptr || CachedOwner == nullptr)
	{
		UE_VLOG_UELOG(this, LogStateTree, Error, TEXT("Trying to call SendEvent() while node is not active. Use SendEvent() on UStateTreeComponent instead for sending signals externally."));
		return;
	}

	FStateTreeTransitionRequest Request;
	Request.SourceState = CachedState;
	Request.TargetState = TargetState.StateHandle;
	Request.Priority = Priority;
	
	InstanceStorage->AddTransitionRequest(CachedOwner, Request);
}

bool UStateTreeNodeBlueprintBase::IsPropertyRefValid(const FStateTreeBlueprintPropertyRef& PropertyRef) const
{
	FProperty* SourceProperty = nullptr;
	return GetMutablePtrToProperty(PropertyRef, SourceProperty) != nullptr;
}

DEFINE_FUNCTION(UStateTreeNodeBlueprintBase::execGetPropertyReference)
{
	P_GET_STRUCT_REF(FStateTreeBlueprintPropertyRef, PropertyRef);
	Stack.StepCompiledIn<FProperty>(nullptr);
	P_FINISH;

	FProperty* SourceProperty = nullptr;
	if (void* PropertyAddress = P_THIS->GetMutablePtrToProperty(PropertyRef, SourceProperty))
	{
		Stack.MostRecentPropertyAddress = reinterpret_cast<uint8*>(PropertyAddress);
		Stack.MostRecentProperty = const_cast<FProperty*>(SourceProperty);
		if (RESULT_PARAM)
		{
			Stack.MostRecentProperty->CopyCompleteValueToScriptVM(RESULT_PARAM, Stack.MostRecentPropertyAddress);
		}
	}
	else
	{
		Stack.MostRecentPropertyAddress = nullptr;
		Stack.MostRecentProperty = nullptr;
	}
}