Do I need to call this(specified function in description) in this place?

Development Programming & Scripting C++
1

DO I need to call this function on a server?
I have a SHealthComponent (which handles the incoming damage) and ExplosiveBarrel – owns the SHealthComponent and add explosion effects

ExplosiveBarrel.h
[SPOILER]




// Fill out your copyright notice in the Description page of Project Settings.

#pragma once

#include "CoreMinimal.h"
#include "GameFramework/Actor.h"
#include "SExplosiveBarrel.generated.h"


class UStaticMeshComponent;
class UParticleSystem;
class USHealthComponent;
class URadialForceComponent;
class UMaterialInterface;

UCLASS()
class COOPGAME_API ASExplosiveBarrel : public AActor
{
    GENERATED_BODY()

public:    
    // Sets default values for this actor's properties
    ASExplosiveBarrel();

protected:
    // Called when the game starts or when spawned
    virtual void BeginPlay() override;

    UPROPERTY(VisibleAnywhere, Category = "Components")
    UStaticMeshComponent* MeshComp;

    UPROPERTY(VisibleAnywhere, Category = "Components")
    USHealthComponent*  HealthComp;

    UPROPERTY(VisibleAnywhere, Category = "Components")
    URadialForceComponent* RadialForceComp;

    UPROPERTY(EditDefaultsOnly, Category = "FX")
    UParticleSystem* ExplosionEffect;

    UPROPERTY(EditDefaultsOnly, Category = "FX")
    float ExplostionImpulse;

    UPROPERTY(EditDefaultsOnly, Category = "FX")
    UMaterialInterface* ExplodedMaterial;

    UFUNCTION()
    void OnHealthChanched(USHealthComponent* OwningHealthComponent, float Health, float HealthDelta, const class UDamageType* DamageType, class AController* InstigatedBy, AActor* DamageCauser);

    // NotifyRep
    UPROPERTY(ReplicatedUsing = OnRep_Exploded)
    bool bIsExploded;

    UFUNCTION()
    void OnRep_Exploded();

    virtual void GetLifetimeReplicatedProps(TArray< FLifetimeProperty > & OutLifetimeProps) const override;
public:    

};

[/SPOILER]
ExplosiveBarrel.cpp
[SPOILER]




// Fill out your copyright notice in the Description page of Project Settings.


#include "Public/SExplosiveBarrel.h"
#include "PhysicsEngine/RadialForceComponent.h"
#include "Public/Components/SHealthComponent.h"
#include "Kismet/GameplayStatics.h"
#include "Net/UnrealNetwork.h"


// Sets default values
ASExplosiveBarrel::ASExplosiveBarrel()
{
    HealthComp = CreateDefaultSubobject<USHealthComponent>(TEXT("HealthComp"));

    MeshComp = CreateDefaultSubobject<UStaticMeshComponent>(TEXT("MeshComp"));
    MeshComp->SetSimulatePhysics(true);
    MeshComp->SetCollisionObjectType(ECC_PhysicsBody);
    RootComponent = MeshComp;

    RadialForceComp = CreateDefaultSubobject<URadialForceComponent>(TEXT("RadialForceComp"));
    RadialForceComp->Radius = 300.0;
    RadialForceComp->bIgnoreOwningActor = true; // ignore self
    RadialForceComp->bAutoActivate = false; // to prevent auto adding force instead use FireImpulse()
    RadialForceComp->bImpulseVelChange = true; // will ignore mass of objects
    RadialForceComp->ImpulseStrength = 400;
    RadialForceComp->SetupAttachment(RootComponent);

    bIsExploded = false;
    ExplostionImpulse = 400.0f;

    HealthComp->OnHealthChanged.AddDynamic(this, &ASExplosiveBarrel::OnHealthChanched);

    SetReplicates(true);
    SetReplicateMovement(true);
}

// Called when the game starts or when spawned
void ASExplosiveBarrel::BeginPlay()
{
    Super::BeginPlay();

}

// full func runs on the server(because OnHealthChanched is ShealthComponent`s function which is called only from server
void ASExplosiveBarrel::OnHealthChanched(USHealthComponent* OwningHealthComponent, float Health, float HealthDelta, const class UDamageType* DamageType, class AController* InstigatedBy, AActor* DamageCauser)
{
    if (bIsExploded) {
        return;
    }


    if (Health == 0.0f) {
        bIsExploded = true;
        // UPROPERTY(ReplicatedUsing = OnRep_Exploded)        bool bIsExploded;
        // so on the variable change, this function will be called

***// DO I need to call this func on a server?***
*** //OnRep_Exploded();
// DO I need to call this func on a server?***
//Because this is already works w/o it. So I think I do not need it, because of **UPROPERTY(ReplicatedUsing = OnRep_Exploded)        bool bIsExploded;**


        FVector BoostIntensity = FVector::UpVector * ExplostionImpulse;
        MeshComp-&gt;AddImpulse(BoostIntensity, NAME_None, true);

        // Blast away nearby objects
        RadialForceComp-&gt;FireImpulse();
    }
}

// this will be called on client
void ASExplosiveBarrel::OnRep_Exploded()
{
    UGameplayStatics::SpawnEmitterAtLocation(GetWorld(), ExplosionEffect, GetActorLocation());
    MeshComp-&gt;SetMaterial(0, ExplodedMaterial);
}


void ASExplosiveBarrel::GetLifetimeReplicatedProps(TArray&lt; FLifetimeProperty &gt; & OutLifetimeProps) const
{
    Super::GetLifetimeReplicatedProps(OutLifetimeProps);

    DOREPLIFETIME(ASExplosiveBarrel, bIsExploded);
}

[/SPOILER]

SHealthComponent.h
[SPOILER]




// Fill out your copyright notice in the Description page of Project Settings.

#pragma once

#include "CoreMinimal.h"
#include "Components/ActorComponent.h"
#include "SHealthComponent.generated.h"


// ** on Health changed event
// ** delta(triangle) - difference, change in quantity; e.g. delta Y = "change in y" or "how much Y changes"
DECLARE_DYNAMIC_MULTICAST_DELEGATE_SixParams(FOnHeaalthChangedSignature, USHealthComponent*, HealthComponent, float, Health, float, HealthDelta, const class UDamageType*, DamageType, class AController*, InstigatedBy, AActor*, DamageCauser);

// our OWN little category ClassGroup=(COOP) - YOU CAN SEE IT  when selecting a component from a dropdown menu
UCLASS( ClassGroup=(COOP), meta=(BlueprintSpawnableComponent) )
class COOPGAME_API USHealthComponent : public UActorComponent
{
    GENERATED_BODY()

public:    
    // Sets default values for this component's properties
    USHealthComponent();

protected:
    // Called when the game starts
    virtual void BeginPlay() override;

    UPROPERTY(EditDefaultsOnly, BlueprintReadOnly, Category = "HealthComponent")
    float DefaultHealth;

    UPROPERTY(Replicated, EditAnywhere, BlueprintReadWrite, Category = "HealthComponent")
    float Health;

    UFUNCTION()
    void HandleTakeAnyDamage(AActor* DamagedActor, float Damage, const class UDamageType* DamageType, class AController* InstigatedBy, AActor* DamageCauser);

    virtual void GetLifetimeReplicatedProps(TArray< FLifetimeProperty > & OutLifetimeProps) const override;

public:

    UPROPERTY(BlueprintAssignable, Category = "Events")
    FOnHeaalthChangedSignature OnHealthChanged;

    float GetCurrentHealth();

};

[/SPOILER]
SHealthComponent.cpp
[SPOILER]




// Fill out your copyright notice in the Description page of Project Settings.


#include "Public/Components/SHealthComponent.h"
#include "Net/UnrealNetwork.h"

USHealthComponent::USHealthComponent()
{
    DefaultHealth= 100.0f;

    SetIsReplicated(true);
}


void USHealthComponent::BeginPlay()
{
    Super::BeginPlay();

    if(GetOwnerRole() == ROLE_Authority) {
        AActor* MyOwner = GetOwner();

        if (!MyOwner) {
            return;
        }

        MyOwner->OnTakeAnyDamage.AddDynamic(this, &USHealthComponent::HandleTakeAnyDamage);
    }
    Health = DefaultHealth;

}

void USHealthComponent::HandleTakeAnyDamage(AActor* DamagedActor, float Damage, const class UDamageType* DamageType, class AController* InstigatedBy, AActor* DamageCauser)
{
    if (Damage <= 0.0f) {
        return;
    }

    Health = FMath::Clamp(Health - Damage, 0.0f, DefaultHealth);

    UE_LOG(LogTemp, Log, TEXT("Health Changed to: %s"), *FString::SanitizeFloat(Health));

    OnHealthChanged.Broadcast(this, Health, Damage, DamageType, InstigatedBy, DamageCauser);
}

float USHealthComponent::GetCurrentHealth()
{
    return Health;
}

void USHealthComponent::GetLifetimeReplicatedProps(TArray< FLifetimeProperty > & OutLifetimeProps) const
{
    Super::GetLifetimeReplicatedProps(OutLifetimeProps);

    DOREPLIFETIME(USHealthComponent, Health);
}
​​​​​​​

[/SPOILER]

2

Oh, only after a restarting the VS I have seen that this is not working w/o this function, So if you do something like this, you should call a function in this situation.

3

OnRep gets called on the clients when necessary as in if the value has changed. OnRep isn’t called on the server.

4

Excellent, thank you for your reply!

How should I call it in BP(if I set RepNotify on a variable, and then it creates a function wich can not be placed, so i can call it in any way in BP as it says: “This function was not called as blueprint callable”)?

5

Blueprint RepNotify also gets called on the server but in C++ you need to call the OnRep_ function manually if you want it to be called on the server.

6

Thanks, I do appreciate your help!:slight_smile: