Section 13: The Enemy Class - Lecture 258

Hide Health Bar

Source/Shooter/Enemy.cpp

@@ -7,7 +7,10 @@
 #include "Particles/ParticleSystemComponent.h"
 
 // Sets default values
-AEnemy::AEnemy()
+AEnemy::AEnemy() :
+	Health(100.f),
+	MaxHealth(100.f),
+	HealthBarDisplayTime(4.f)
 {
  	// Set this character to call Tick() every frame.  You can turn this off to improve performance if you don't need it.
 	PrimaryActorTick.bCanEverTick = true;
@@ -22,6 +25,12 @@ void AEnemy::BeginPlay()
 	GetMesh()->SetCollisionResponseToChannel(ECollisionChannel::ECC_Visibility, ECollisionResponse::ECR_Block);
 }
 
+void AEnemy::ShowHealthBar_Implementation()
+{
+	GetWorldTimerManager().ClearTimer(HealthBarTimer);
+	GetWorldTimerManager().SetTimer(HealthBarTimer, this, &AEnemy::HideHealthBar, HealthBarDisplayTime);
+}
+
 // Called every frame
 void AEnemy::Tick(float DeltaTime)
 {
@@ -47,5 +56,23 @@ void AEnemy::BulletHit_Implementation(FHitResult HitResult)
 	{
 		UGameplayStatics::SpawnEmitterAtLocation(GetWorld(), ImpactParticles, HitResult.Location, FRotator(0.f), true);
 	}
+	
+	ShowHealthBar();
+}
+
+float AEnemy::TakeDamage(float DamageAmount, FDamageEvent const& DamageEvent, AController* EventInstigator,
+	AActor* DamageCauser)
+{
+	float DamageInflicted = DamageAmount;
+	if (Health - DamageAmount <= 0.f)
+	{
+		DamageInflicted = Health; 
+		Health = 0.f;
+	}
+	else
+	{
+		Health -= DamageAmount;
+	}
+	return DamageInflicted;
 }
 

Source/Shooter/Enemy.h

@@ -23,6 +23,14 @@ protected:
 	// Called when the game starts or when spawned
 	virtual void BeginPlay() override;
 
+	UFUNCTION(BlueprintNativeEvent)
+	void ShowHealthBar();
+	void ShowHealthBar_Implementation();
+
+	UFUNCTION(BlueprintImplementableEvent)
+	void HideHealthBar();
+	
+private:
 	/** Particles to spawn when hit by bullets */
 	UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = Combat, meta = (AllowPrivateAccess = true))
 	UParticleSystem* ImpactParticles;
@@ -30,6 +38,23 @@ protected:
 	/** Sound to play when hit by bullets */
 	UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = Combat, meta = (AllowPrivateAccess = true))
 	USoundCue* ImpactSound;
+
+	/** Current health */
+	UPROPERTY(VisibleAnywhere, BlueprintReadOnly, Category = Combat, meta = (AllowPrivateAccess = true))
+	float Health;
+
+	UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = Combat, meta = (AllowPrivateAccess = true))
+	float MaxHealth;
+
+	/** Name of the head bone */
+	UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = Combat, meta = (AllowPrivateAccess = true))
+	FString HeadBone;
+
+	/** Time to display health bar once shot */
+	UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = Combat, meta = (AllowPrivateAccess = true))
+	float HealthBarDisplayTime;
+	
+	FTimerHandle HealthBarTimer;
 public:	
 	// Called every frame
 	virtual void Tick(float DeltaTime) override;
@@ -38,4 +63,8 @@ public:
 	virtual void SetupPlayerInputComponent(class UInputComponent* PlayerInputComponent) override;
 
 	virtual void BulletHit_Implementation(FHitResult HitResult) override;
+
+	virtual float TakeDamage(float DamageAmount, FDamageEvent const& DamageEvent, AController* EventInstigator, AActor* DamageCauser) override;
+
+	FORCEINLINE FString GetHeadBone() const { return HeadBone; }
 };

Source/Shooter/ShooterCharacter.cpp

@@ -6,8 +6,6 @@
 
 #include "Item.h"
 #include "Camera/CameraComponent.h"
-#include "Components/SphereComponent.h"
-#include "Components/BoxComponent.h"
 #include "Components/CapsuleComponent.h"
 #include "Components/WidgetComponent.h"
 #include "Engine/SkeletalMeshSocket.h"
@@ -18,8 +16,8 @@
 #include "Sound/SoundCue.h"
 #include "Ammo.h"
 #include "BulletHitInterface.h"
+#include "Enemy.h"
 #include "PhysicalMaterials/PhysicalMaterial.h"
-#include "Shooter.h"
 
 // Sets default values
 AShooterCharacter::AShooterCharacter() :
@@ -662,22 +660,46 @@ void AShooterCharacter::SendBullet()
 	// Spawn impact particles after updating BeamEndPoint
 	
 	// Does hit actor implement BulletHitInterface?
-	IBulletHitInterface* BulletHitInterface = nullptr;
-	if (IsValid(BeamHitResult.GetActor()) &&
-		(BulletHitInterface = Cast<IBulletHitInterface>(BeamHitResult.GetActor())) != nullptr)
+	bool spawnGenericImpactParticles = false;
+	if (IsValid(BeamHitResult.GetActor()))
+	{
+		if (IBulletHitInterface* BulletHitInterface = Cast<IBulletHitInterface>(BeamHitResult.GetActor()))
 		{
 			BulletHitInterface->BulletHit_Implementation(BeamHitResult);
-		UE_LOG(LogTemp, Warning, TEXT("actor particle"));
-		GEngine->AddOnScreenDebugMessage(-1, 5.f, FColor::Red, TEXT("actor particle"));
 		}
 		else
 		{
-		if (ImpactParticles)
+			spawnGenericImpactParticles = true;
+		}
+
+		if (AEnemy* HitEnemy = Cast<AEnemy>(BeamHitResult.GetActor()))
+		{
+			float damageToApply;
+			if (BeamHitResult.BoneName.ToString() == HitEnemy->GetHeadBone())
+			{
+				damageToApply = EquippedWeapon->GetHeadshotDamage();
+			}
+			else
+			{
+				damageToApply = EquippedWeapon->GetDamage();
+			}
+			
+			UGameplayStatics::ApplyDamage(HitEnemy,
+				damageToApply,
+				GetController(), this,
+				UDamageType::StaticClass());
+			UE_LOG(LogTemp, Warning, TEXT("Hit Component: %s"), *BeamHitResult.BoneName.ToString());
+		}
+	}
+	else
+	{
+		spawnGenericImpactParticles = true;
+	}
+	
+	if (ImpactParticles && spawnGenericImpactParticles)
 	{
 		UGameplayStatics::SpawnEmitterAtLocation(GetWorld(), ImpactParticles,
 			BeamHitResult.Location);
-			UE_LOG(LogTemp, Warning, TEXT("normal particle"));
-		}
 	}
 	
 	// Spawn smoke trail particles

Source/Shooter/Weapon.cpp

@@ -156,6 +156,8 @@ void AWeapon::OnConstruction(const FTransform& Transform)
 			}
 
 			bAutomatic = WeaponDataRow->bAutomatic;
+			Damage = WeaponDataRow->Damage;
+			HeadshotDamage = WeaponDataRow->HeadshotDamage;
 		}
 
 		if (GetMaterialInstance())

Source/Shooter/Weapon.h

@@ -90,6 +90,12 @@ struct FWeaponDataTable : public FTableRowBase
 
 	UPROPERTY(EditAnywhere, BlueprintReadWrite)
 	bool bAutomatic;
+	
+	UPROPERTY(EditAnywhere, BlueprintReadWrite)
+	float Damage;
+	
+	UPROPERTY(EditAnywhere, BlueprintReadWrite)
+	float HeadshotDamage;
 };
 
 /**
@@ -221,6 +227,12 @@ private:
 	UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = "Weapon Properties", meta = (AllowPrivateAccess = "true"))
 	bool bAutomatic;
 
+	/** Amount of damage caused by bullet */
+	UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = "Weapon Properties", meta = (AllowPrivateAccess = "true"))
+	float Damage;
+	
+	UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = "Weapon Properties", meta = (AllowPrivateAccess = "true"))
+	float HeadshotDamage;
 public:
 	/** Adds an impulse to the weapon */
 	void ThrowWeapon();
@@ -239,6 +251,8 @@ public:
 	FORCEINLINE UParticleSystem* GetMuzzleFlash() const { return MuzzleFlash; }
 	FORCEINLINE USoundCue* GetFireSound() const { return FireSound; }
 	FORCEINLINE bool GetAutomatic() const { return bAutomatic; }
+	FORCEINLINE float GetDamage() const { return Damage; }
+	FORCEINLINE float GetHeadshotDamage() const { return HeadshotDamage; }
 
 	void StartSlideTimer();