UE5中GAS接入增强输入(EnhancedInput)

前言

UE5 GAS能够直接支持引擎常规输入, 在GA中能触发Wait Input Press、Wait Input Release等Task, 从而制作一些蓄力能力。
问题：项目使用的增强输入插件来完成更多的输入控制，但GAS本身对增强输入插件没有做支持，官方文档也没有做明确的描述，如何将GAS接入增强输入？

接入常规输入（参考官网文档4.6.2）

常规输入设置

接入步骤

声明InputID枚举

UENUM(BlueprintType)
enum class EUpCoAbilityInputID : uint8
{
	// 0 None
	None			UMETA(DisplayName = "None"),
	Confirm			UMETA(DisplayName = "Confirm"),
	Cancel			UMETA(DisplayName = "Cancel"),
	NormalAttack    UMETA(DisplayName = "NormalAttack"),
};

在GameplayAbility的子类中声明两个变量,AbilityInputID与AbilityID,用于此GA对应的Input枚举，并在GA中设置对应的枚举

UCLASS()
class UPGRADECOLLECTOR_API UUpCoGameplayAbility : public UGameplayAbility
{
	GENERATED_BODY()
public:

	// Abilities with this set will automatically activate when the input is pressed
	UPROPERTY(BlueprintReadOnly, EditAnywhere, Category = "Ability")
	EUpCoAbilityInputID AbilityInputID = EUpCoAbilityInputID::None;

	// Value to associate an ability with an slot without tying it to an automatically activated input.
	// Passive abilities won't be tied to an input so we need a way to generically associate abilities with slots.
	UPROPERTY(BlueprintReadOnly, EditAnywhere, Category = "Ability")
	EUpCoAbilityInputID AbilityID = EUpCoAbilityInputID::None;
	
};

在GiveAbility的时候，将GA与InputID Bind

void AUpCoCharacterBase::AddCharacterAbilities()
{
	// Grant abilities, but only on the server	
	if (GetLocalRole() != ROLE_Authority || !AbilitySystemComponent.IsValid() || AbilitySystemComponent->
		bCharacterAbilitiesGiven)
	{
		return;
	}

	for (TSubclassOf<UUpCoGameplayAbility>& StartupAbility : CharacterAbilities)
	{
		AbilitySystemComponent->GiveAbility(FGameplayAbilitySpec(StartupAbility,1, static_cast<int32>(StartupAbility.GetDefaultObject()->AbilityInputID),this));
	}

	AbilitySystemComponent->bCharacterAbilitiesGiven = true;
}

在Character SetupPlayerInputComponent中调用AbilitySystemComponent的BindAbilityActivationToInputComponent方法完成Bind

void AUpCoCharacterBase::SetupPlayerInputComponent(UInputComponent* PlayerInputComponent)
{
	Super::SetupPlayerInputComponent(PlayerInputComponent);
	BindASCInput();
}

void AUpCoCharacterBase::BindASCInput()
{
AbilitySystemComponent->BindAbilityActivationToInputComponent(InputComponent, FGameplayAbilityInputBinds(
	FString("ConfirmTarget"), // 对应着 ProjectSettings里面的Action名称
	FString("CancelTarget"), // 对应着 ProjectSettings里面的Action名称
	FTopLevelAssetPath("/Script/UpgradeCollector", TEXT("EUpCoAbilityInputID")), // 对应着枚举名称
	static_cast<int32>(EUpCoAbilityInputID::Confirm), //  Confirm
	static_cast<int32>(EUpCoAbilityInputID::Cancel) //  Cancel
	));															  ));
}

测试

增强输入

增强输入设置

接入思路

分析常规输入的接入bind，关键是AbilitySystemComponent中的BindAbilityActivationToInputComponent方法
源码

void UAbilitySystemComponent::BindAbilityActivationToInputComponent(UInputComponent* InputComponent, FGameplayAbilityInputBinds BindInfo)
{
	UEnum* EnumBinds = BindInfo.GetBindEnum();

	SetBlockAbilityBindingsArray(BindInfo);

	for(int32 idx=0; idx < EnumBinds->NumEnums(); ++idx)
	{
		const FString FullStr = EnumBinds->GetNameStringByIndex(idx);
		
		// Pressed event
		{
			FInputActionBinding AB(FName(*FullStr), IE_Pressed);
			AB.ActionDelegate.GetDelegateForManualSet().BindUObject(this, &UAbilitySystemComponent::AbilityLocalInputPressed, idx);
			InputComponent->AddActionBinding(AB);
		}

		// Released event
		{
			FInputActionBinding AB(FName(*FullStr), IE_Released);
			AB.ActionDelegate.GetDelegateForManualSet().BindUObject(this, &UAbilitySystemComponent::AbilityLocalInputReleased, idx);
			InputComponent->AddActionBinding(AB);
		}
	}

	// Bind Confirm/Cancel. Note: these have to come last!
	if (BindInfo.ConfirmTargetCommand.IsEmpty() == false)
	{
		FInputActionBinding AB(FName(*BindInfo.ConfirmTargetCommand), IE_Pressed);
		AB.ActionDelegate.GetDelegateForManualSet().BindUObject(this, &UAbilitySystemComponent::LocalInputConfirm);
		InputComponent->AddActionBinding(AB);
	}
	
	if (BindInfo.CancelTargetCommand.IsEmpty() == false)
	{
		FInputActionBinding AB(FName(*BindInfo.CancelTargetCommand), IE_Pressed);
		AB.ActionDelegate.GetDelegateForManualSet().BindUObject(this, &UAbilitySystemComponent::LocalInputCancel);
		InputComponent->AddActionBinding(AB);
	}

	if (BindInfo.CancelTargetInputID >= 0)
	{
		GenericCancelInputID = BindInfo.CancelTargetInputID;
	}
	if (BindInfo.ConfirmTargetInputID >= 0)
	{
		GenericConfirmInputID = BindInfo.ConfirmTargetInputID;
	}
}

其实发现在常规输入的情况下，InputComponent Bind几个Action，分别对应

AbilityLocalInputPressed
AbilityLocalInputReleased
LocalInputConfirm
LocalInputCancel

然后通过能力中的枚举ID关联起来了。

于是我们提出新的针对增强输入的解决方案

使用EnhancedInputComponent的方法进行bind

// Pressed event
{
	EnhancedInputComponent->BindAction(InputAction, ETriggerEvent::Started,this, &UAbilitySystemComponent::AbilityLocalInputPressed, idx);
}

// Released event
{
	EnhancedInputComponent->BindAction(InputAction, ETriggerEvent::Completed,this, &UAbilitySystemComponent::AbilityLocalInputReleased, idx);
}

InputID枚举值映射InputAction

具体接入步骤

继承AbilitySystemComponent，在子类中重写BindAbilityActivationToInputComponent方法

.h文件

UCLASS()
class UPGRADECOLLECTOR_API UUpCoAbilitySystemComponent : public UAbilitySystemComponent
{
	GENERATED_BODY()
public:
	bool bCharacterAbilitiesGiven = false;
	bool bStartupEffectsApplied = false;
	virtual void BindAbilityActivationToInputComponent(UInputComponent* InputComponent, FGameplayAbilityInputBinds BindInfo) override;
};

.cpp文件

void UUpCoAbilitySystemComponent::BindAbilityActivationToInputComponent(UInputComponent* InputComponent,
                                                                        FGameplayAbilityInputBinds BindInfo)
{
	Super::BindAbilityActivationToInputComponent(InputComponent, BindInfo);
	UEnhancedInputComponent* EnhancedInputComponent = Cast<UEnhancedInputComponent>(InputComponent);
	AUpCoCharacterBase* UpCoCharacter = Cast<AUpCoCharacterBase>(GetAvatarActor());
	if(!UpCoCharacter)
	{
		return;
	}
	TMap<EUpCoAbilityInputID, UInputAction*> CurrentMap = UpCoCharacter->GetEnumMap();
	
	if(EnhancedInputComponent)
	{
		UEnum* EnumBinds = BindInfo.GetBindEnum();
		SetBlockAbilityBindingsArray(BindInfo);
		for(int32 idx=0; idx < EnumBinds->NumEnums(); ++idx)
		{
			// const FString FullStr = EnumBinds->GetNameStringByIndex(idx)
			UInputAction* InputAction = CurrentMap.FindRef(static_cast<EUpCoAbilityInputID>(idx));
			if(InputAction)
			{
				// Pressed event
				{
					EnhancedInputComponent->BindAction(InputAction, ETriggerEvent::Started,this, &UAbilitySystemComponent::AbilityLocalInputPressed, idx);
				}

				// Released event
				{
					EnhancedInputComponent->BindAction(InputAction, ETriggerEvent::Completed,this, &UAbilitySystemComponent::AbilityLocalInputReleased, idx);
				}
			}
		}
	}
}