虚幻引擎5 GAS开发俯视角RPG游戏 #06-7：无限游戏效果

一. 无限游戏效果策略:

1.添加枚举

Source/CC_Aura/Public/Actor/CC_EffectActor.h:

//效果应用策略枚举
UENUM(BlueprintType) 
enum class EEffectApplicationPolicy :uint8		//使用BlueprintType标记的枚举类型目前仅支持uint8作为基础类型。
{
	ApplyOnOverlap,			//重叠时应用
	ApplyOnEndOverlap,		//结束重叠时应用
	DoNotApply				
};

//效果移除策略枚举
UENUM(BlueprintType) 
enum class EEffectRemovalPolicy :uint8
{
	RemoveOnEndOverlap,		//在结束重叠时移除
	DoNotRemove
};

赋值:

	//给对象添加效果
	UFUNCTION(BlueprintCallable)
	void ApplyEffectToTarget(AActor* TargetActor, TSubclassOf<UGameplayEffect> GameplayEffectClass);
	
	//即时游戏效果
	UPROPERTY(EditAnywhere, BlueprintReadOnly, Category = "Applied Effects")
	TSubclassOf<UGameplayEffect> InstantGameplayEffectClass;
	
	UPROPERTY(EditAnywhere, BlueprintReadOnly, Category="Apply Effects")
	EEffectApplicationPolicy InstantEffectApplicationPolicy = EEffectApplicationPolicy::DoNotApply;
	
	//持续游戏效果
	UPROPERTY(EditAnywhere, BlueprintReadOnly, Category = "Applied Effects")
	TSubclassOf<UGameplayEffect> DurationGameplayEffectClass;

	UPROPERTY(EditAnywhere, BlueprintReadOnly, Category="Apply Effects")
	EEffectApplicationPolicy DurationEffectApplicationPolicy = EEffectApplicationPolicy::DoNotApply;
	
	//无限游戏效果
	UPROPERTY(EditAnywhere, BlueprintReadOnly, Category = "Applied Effects")
	TSubclassOf<UGameplayEffect> InfiniteGameplayEffectClass;

	UPROPERTY(EditAnywhere, BlueprintReadOnly, Category="Apply Effects")
	EEffectApplicationPolicy InfinityEffectApplicationPolicy = EEffectApplicationPolicy::DoNotApply;

	UPROPERTY(EditAnywhere, BlueprintReadOnly, Category="Apply Effects")
	EEffectRemovalPolicy InfinityEffectRemovalPolicy = EEffectRemovalPolicy::RemoveOnEndOverlap;

2.添加函数:

	//在重叠开始时处理效果的添加删除逻辑
	UFUNCTION(BlueprintCallable) 
	void OnOverlap(AActor* TargetActor);

	//在重叠结束时处理效果的添加删除逻辑
	UFUNCTION(BlueprintCallable) 
	void OnEndOverlap(AActor* TargetActor);
	

在Source/CC_Aura/Private/Actor/CC_EffectActor.cpp:

void ACC_EffectActor::OnOverlap(AActor* TargetActor)
{
	//即时效果
	if (InstantEffectApplicationPolicy == EEffectApplicationPolicy::ApplyOnOverlap)
	{
		ApplyEffectToTarget(TargetActor, InstantGameplayEffectClass);
	}
	//持续效果
	if (DurationEffectApplicationPolicy ==  EEffectApplicationPolicy::ApplyOnOverlap)
	{
		ApplyEffectToTarget(TargetActor, DurationGameplayEffectClass);
	}
	//无限效果
	if (InfinityEffectApplicationPolicy ==  EEffectApplicationPolicy::ApplyOnOverlap)
	{
		ApplyEffectToTarget(TargetActor, InfiniteGameplayEffectClass);
	}
}

3.修改ApplyEffectToTarget函数,当无限效果时,保存效果规格句柄:

void ACC_EffectActor::ApplyEffectToTarget(AActor* TargetActor, TSubclassOf<UGameplayEffect> GameplayEffectClass)
{
	checkf(GameplayEffectClass, TEXT("%s中:GameplayEffectClass没有设置!!!"), *GetName());
	//1.获取目标Actor的AbilitySystemComponent组件
	UAbilitySystemComponent* TargetASC = UAbilitySystemBlueprintLibrary::GetAbilitySystemComponent(TargetActor);
	if (TargetASC == nullptr) return;
	
	//2.创建效果上下文句柄
	FGameplayEffectContextHandle EffectContextHandle = TargetASC->MakeEffectContext();
	EffectContextHandle.AddSourceObject(this);		//设置效果来源对象为当前EffectActor

	//3.创建效果规格句柄(Spec)
	const FGameplayEffectSpecHandle EffectSpecHandle = TargetASC->MakeOutgoingSpec(GameplayEffectClass, 1.f, EffectContextHandle);

	//4.应用效果
	const FActiveGameplayEffectHandle ActiveGameplayEffectHandle = TargetASC->ApplyGameplayEffectSpecToSelf(*EffectSpecHandle.Data.Get());

	//5.如果是无限效果,存储权柄信息
	const bool bIsInfinite = EffectSpecHandle.Data.Get()->Def.Get()->DurationPolicy == EGameplayEffectDurationType::Infinite;
		//无限效果 && 结束覆盖时移除
	if (bIsInfinite && InfinityEffectRemovalPolicy == EEffectRemovalPolicy::RemoveOnEndOverlap)
	{
		//存储信息
		ActiveEffectHandles.Add(ActiveGameplayEffectHandle, TargetASC);
	}
}

4.结束重叠时,触发事件函数:

void ACC_EffectActor::OnEndOverlap(AActor* TargetActor)
{
	//添加效果
	if(InstantEffectApplicationPolicy == EEffectApplicationPolicy::ApplyOnEndOverlap)
	{
		ApplyEffectToTarget(TargetActor, InstantGameplayEffectClass);
	}

	if(DurationEffectApplicationPolicy == EEffectApplicationPolicy::ApplyOnEndOverlap)
	{
		ApplyEffectToTarget(TargetActor, DurationGameplayEffectClass);
	}

	if(InfinityEffectApplicationPolicy == EEffectApplicationPolicy::ApplyOnEndOverlap)
	{
		ApplyEffectToTarget(TargetActor, InfiniteGameplayEffectClass);
	}

	//手动结束无限效果
	if (InfinityEffectRemovalPolicy ==  EEffectRemovalPolicy::RemoveOnEndOverlap)
	{
		//1.获取目标Actor的AbilitySystemComponent组件
		UAbilitySystemComponent* TargetASC = UAbilitySystemBlueprintLibrary::GetAbilitySystemComponent(TargetActor);
		if (!IsValid(TargetASC)) return;

		//创建存储需要移除的效果句柄存储Key，用于遍历完成后移除效果
		TArray<FActiveGameplayEffectHandle> HandlesToRemove;

		//循环map内存的数据
		for(TTuple<FActiveGameplayEffectHandle, UAbilitySystemComponent*> HandlePair : ActiveEffectHandles)
		{
			//判断是否ASC相同
			if(TargetASC == HandlePair.Value)
			{
				//通过句柄将效果移除，注意，有可能有多层效果，不能将其它层的效果也移除掉，所以只移除一层
				TargetASC->RemoveActiveGameplayEffect(HandlePair.Key, 1);
				//添加到移除列表
				HandlesToRemove.Add(HandlePair.Key);
			}
		}

		//遍历完成后，在Map中将移除效果的KeyValue删除
		for(auto& Handle : HandlesToRemove)
		{
			ActiveEffectHandles.FindAndRemoveChecked(Handle);
		}
	}
}

5.在BP_FireArea: 

6.火焰效果:

源代码:

Source/CC_Aura/Public/Actor/CC_EffectActor.h:

// 版权归陈超所有

#pragma once

#include "CoreMinimal.h"
#include "ActiveGameplayEffectHandle.h"
#include "GameFramework/Actor.h"
#include "CC_EffectActor.generated.h"

//struct FActiveGameplayEffectHandle;
class UAbilitySystemComponent;
class UGameplayEffect;
class USphereComponent;
class UStaticMeshComponent;

//效果应用策略枚举
UENUM(BlueprintType) 
enum class EEffectApplicationPolicy :uint8		//使用BlueprintType标记的枚举类型目前仅支持uint8作为基础类型。
{
	ApplyOnOverlap,			//重叠时应用
	ApplyOnEndOverlap,		//结束重叠时应用
	DoNotApply				
};

//效果移除策略枚举
UENUM(BlueprintType) 
enum class EEffectRemovalPolicy :uint8
{
	RemoveOnEndOverlap,		//在结束重叠时移除
	DoNotRemove
};


UCLASS()
class CC_AURA_API ACC_EffectActor : public AActor
{
	GENERATED_BODY()
	
public:	
	ACC_EffectActor();

protected:
	virtual void BeginPlay() override;

	//给对象添加效果
	UFUNCTION(BlueprintCallable)
	void ApplyEffectToTarget(AActor* TargetActor, TSubclassOf<UGameplayEffect> GameplayEffectClass);
	
	//在重叠开始时处理效果的添加删除逻辑
	UFUNCTION(BlueprintCallable) 
	void OnOverlap(AActor* TargetActor);

	//在重叠结束时处理效果的添加删除逻辑
	UFUNCTION(BlueprintCallable) 
	void OnEndOverlap(AActor* TargetActor);
	
	//即时游戏效果
	UPROPERTY(EditAnywhere, BlueprintReadOnly, Category = "Applied Effects")
	TSubclassOf<UGameplayEffect> InstantGameplayEffectClass;
	
	UPROPERTY(EditAnywhere, BlueprintReadOnly, Category="Apply Effects")
	EEffectApplicationPolicy InstantEffectApplicationPolicy = EEffectApplicationPolicy::DoNotApply;
	
	//持续游戏效果
	UPROPERTY(EditAnywhere, BlueprintReadOnly, Category = "Applied Effects")
	TSubclassOf<UGameplayEffect> DurationGameplayEffectClass;

	UPROPERTY(EditAnywhere, BlueprintReadOnly, Category="Apply Effects")
	EEffectApplicationPolicy DurationEffectApplicationPolicy = EEffectApplicationPolicy::DoNotApply;
	
	//无限游戏效果
	UPROPERTY(EditAnywhere, BlueprintReadOnly, Category = "Applied Effects")
	TSubclassOf<UGameplayEffect> InfiniteGameplayEffectClass;

	UPROPERTY(EditAnywhere, BlueprintReadOnly, Category="Apply Effects")
	EEffectApplicationPolicy InfinityEffectApplicationPolicy = EEffectApplicationPolicy::DoNotApply;	//无限效果应用效果

	UPROPERTY(EditAnywhere, BlueprintReadOnly, Category="Apply Effects")
	EEffectRemovalPolicy InfinityEffectRemovalPolicy = EEffectRemovalPolicy::RemoveOnEndOverlap;	//无限效果移除策略

	//用于存储当前已经激活的GameplayEffect的句柄的map
	TMap<FActiveGameplayEffectHandle, UAbilitySystemComponent*> ActiveEffectHandles;
};

Source/CC_Aura/Private/Actor/CC_EffectActor.cpp:

// 版权归陈超所有


#include "Actor/CC_EffectActor.h"

#include "AbilitySystemComponent.h"
#include "AbilitySystemBlueprintLibrary.h"

ACC_EffectActor::ACC_EffectActor()
{
 	// 将此参与者设置为每帧调用Tick（）。如果你不需要它，你可以关闭它来提高性能。
	PrimaryActorTick.bCanEverTick = false;

	SetRootComponent(CreateDefaultSubobject<USceneComponent>("SceneRoot"));
}

// 在游戏开始或生成时调用
void ACC_EffectActor::BeginPlay()
{
	Super::BeginPlay();
}

void ACC_EffectActor::ApplyEffectToTarget(AActor* TargetActor, TSubclassOf<UGameplayEffect> GameplayEffectClass)
{
	checkf(GameplayEffectClass, TEXT("%s中:GameplayEffectClass没有设置!!!"), *GetName());
	//1.获取目标Actor的AbilitySystemComponent组件
	UAbilitySystemComponent* TargetASC = UAbilitySystemBlueprintLibrary::GetAbilitySystemComponent(TargetActor);
	if (TargetASC == nullptr) return;
	
	//2.创建效果上下文句柄
	FGameplayEffectContextHandle EffectContextHandle = TargetASC->MakeEffectContext();
	EffectContextHandle.AddSourceObject(this);		//设置效果来源对象为当前EffectActor

	//3.创建效果规格句柄(Spec)
	const FGameplayEffectSpecHandle EffectSpecHandle = TargetASC->MakeOutgoingSpec(GameplayEffectClass, 1.f, EffectContextHandle);

	//4.应用效果
	const FActiveGameplayEffectHandle ActiveGameplayEffectHandle = TargetASC->ApplyGameplayEffectSpecToSelf(*EffectSpecHandle.Data.Get());

	//5.如果是无限效果,存储权柄信息
	const bool bIsInfinite = EffectSpecHandle.Data.Get()->Def.Get()->DurationPolicy == EGameplayEffectDurationType::Infinite;
		//无限效果 && 结束覆盖时移除
	if (bIsInfinite && InfinityEffectRemovalPolicy == EEffectRemovalPolicy::RemoveOnEndOverlap)
	{
		//存储信息
		ActiveEffectHandles.Add(ActiveGameplayEffectHandle, TargetASC);
	}
}

void ACC_EffectActor::OnOverlap(AActor* TargetActor)
{
	//即时效果
	if (InstantEffectApplicationPolicy == EEffectApplicationPolicy::ApplyOnOverlap)
	{
		ApplyEffectToTarget(TargetActor, InstantGameplayEffectClass);
	}
	//持续效果
	if (DurationEffectApplicationPolicy ==  EEffectApplicationPolicy::ApplyOnOverlap)
	{
		ApplyEffectToTarget(TargetActor, DurationGameplayEffectClass);
	}
	//无限效果
	if (InfinityEffectApplicationPolicy ==  EEffectApplicationPolicy::ApplyOnOverlap)
	{
		ApplyEffectToTarget(TargetActor, InfiniteGameplayEffectClass);
	}
}

void ACC_EffectActor::OnEndOverlap(AActor* TargetActor)
{
	//添加效果
	if(InstantEffectApplicationPolicy == EEffectApplicationPolicy::ApplyOnEndOverlap)
	{
		ApplyEffectToTarget(TargetActor, InstantGameplayEffectClass);
	}

	if(DurationEffectApplicationPolicy == EEffectApplicationPolicy::ApplyOnEndOverlap)
	{
		ApplyEffectToTarget(TargetActor, DurationGameplayEffectClass);
	}

	if(InfinityEffectApplicationPolicy == EEffectApplicationPolicy::ApplyOnEndOverlap)
	{
		ApplyEffectToTarget(TargetActor, InfiniteGameplayEffectClass);
	}

	//手动结束无限效果
	if (InfinityEffectRemovalPolicy ==  EEffectRemovalPolicy::RemoveOnEndOverlap)
	{
		//1.获取目标Actor的AbilitySystemComponent组件
		UAbilitySystemComponent* TargetASC = UAbilitySystemBlueprintLibrary::GetAbilitySystemComponent(TargetActor);
		if (!IsValid(TargetASC)) return;

		//创建存储需要移除的效果句柄存储Key，用于遍历完成后移除效果
		TArray<FActiveGameplayEffectHandle> HandlesToRemove;

		//循环map内存的数据
		for(TTuple<FActiveGameplayEffectHandle, UAbilitySystemComponent*> HandlePair : ActiveEffectHandles)
		{
			//判断是否ASC相同
			if(TargetASC == HandlePair.Value)
			{
				//通过句柄将效果移除，注意，有可能有多层效果，不能将其它层的效果也移除掉，所以只移除一层
				TargetASC->RemoveActiveGameplayEffect(HandlePair.Key, 1);
				//添加到移除列表
				HandlesToRemove.Add(HandlePair.Key);
			}
		}

		//遍历完成后，在Map中将移除效果的KeyValue删除
		for(auto& Handle : HandlesToRemove)
		{
			ActiveEffectHandles.FindAndRemoveChecked(Handle);
		}
	}
}