FireWeapon 함수를 리팩토링 하다.

너무 하는게 많고 길었던 FireWeapon 함수에서 Ray Trace 를 통해 끝점을 구하는 부분을 따로 함수로 빼서 FireWeapon 함수를 간략하게 정리했다.

bool AShooterCharacter::GetBeamEndLocation(const FVector& MuzzleSocketLocation, FVector& OutBeamLocation)
{
	// Get Current size of the view port
	FVector2D ViewportSize;
	if (GEngine && GEngine->GameViewport)
	{
		GEngine->GameViewport->GetViewportSize(ViewportSize);
	} 

	//Get Screen space of crosshairs
	FVector2D CrosshairLocation(ViewportSize.X / 2.f, ViewportSize.Y / 2.f);
	CrosshairLocation.Y -= 50.0f;
	FVector CrosshairWorldPosition;
	FVector CrosshairWorldDirection;

	//Get World position and direction of crosshairs
	bool bScreenToWorld = UGameplayStatics::DeprojectScreenToWorld(UGameplayStatics::GetPlayerController(this, 0)
		, CrosshairLocation
		, CrosshairWorldPosition
		, CrosshairWorldDirection);

	// was deprojection successful?
	if (bScreenToWorld)
	{
		FHitResult ScreenTraceHit;
		const FVector Start{ CrosshairWorldPosition };
		const FVector End{ CrosshairWorldPosition + CrosshairWorldDirection * 50'000.f };

		// Set beam end point  to line trace end point
		OutBeamLocation = End;

		// Trace outward from crosshairs world location
		GetWorld()->LineTraceSingleByChannel(ScreenTraceHit
			, Start
			, End
			, ECollisionChannel::ECC_Visibility);
		// was ther a tarce hit?
		if (ScreenTraceHit.bBlockingHit)
		{
			// Beam end point is now trace hit location
			OutBeamLocation = ScreenTraceHit.Location;
		}

		// Perform a second trace , this tim from the gun barrel
		FHitResult WeaponTraceHit;
		const FVector WeaponTraceStart{ MuzzleSocketLocation };
		const FVector WeaponTraceEnd{ OutBeamLocation };
		GetWorld()->LineTraceSingleByChannel(WeaponTraceHit
			, WeaponTraceStart
			, WeaponTraceEnd
			, ECollisionChannel::ECC_Visibility);
		// Object between barrel and BeamEndPoint?
		if (WeaponTraceHit.bBlockingHit)
			OutBeamLocation = WeaponTraceHit.Location;
		
		return true;
	}

	return false;
}

변경 전

void AShooterCharacter::FireWeapon()
{
	UE_LOG(LogTemp, Warning, TEXT("Fire Weapon."));
	if (FireSound)
	{
		UGameplayStatics::PlaySound2D(this, FireSound);
	}

	const USkeletalMeshSocket* BarrelSocket = GetMesh()->GetSocketByName("Barrel");
	if (BarrelSocket)
	{
		const FTransform SocketTransform = BarrelSocket->GetSocketTransform(GetMesh());
		
		if (MuzzleFlash)
		{
			UGameplayStatics::SpawnEmitterAtLocation(GetWorld(), MuzzleFlash, SocketTransform);
		}

		// Get Current size of the view port
		FVector2D ViewportSize;
		if (GEngine && GEngine->GameViewport)
		{
			GEngine->GameViewport->GetViewportSize(ViewportSize);
		}

		//Get Screen space of crosshairs
		FVector2D CrosshairLocation(ViewportSize.X / 2.f, ViewportSize.Y / 2.f);
		CrosshairLocation.Y -= 50.0f;

		FVector CrosshairWorldPosition;
		FVector CrosshairWorldDirection;

		//Get World position and direction of crosshairs
		bool bScreenToWorld = UGameplayStatics::DeprojectScreenToWorld(UGameplayStatics::GetPlayerController(this, 0)
																							, CrosshairLocation
																							, CrosshairWorldPosition
																							, CrosshairWorldDirection);
		// was deprojection successful?
		if (bScreenToWorld)
		{
			FHitResult ScreenTraceHit;
			const FVector Start{ CrosshairWorldPosition };
			const FVector End{ CrosshairWorldPosition + CrosshairWorldDirection * 50'000.f };

			// Set beam end point  to line trace end point
			FVector BeamEndPoint{ End };
			// Trace outward from crosshairs world location
			GetWorld()->LineTraceSingleByChannel(ScreenTraceHit
														, Start	
														, End
														, ECollisionChannel::ECC_Visibility);
			// was ther a tarce hit?
			if (ScreenTraceHit.bBlockingHit)
			{
				// Beam end point is now trace hit location
				BeamEndPoint = ScreenTraceHit.Location;
			}

			// Perform a second trace , this tim from the gun barrel
			FHitResult WeaponTraceHit;
			const FVector WeaponTraceStart{ SocketTransform.GetLocation() };
			const FVector WeaponTraceEnd{ BeamEndPoint };
			GetWorld()->LineTraceSingleByChannel(WeaponTraceHit
														, WeaponTraceStart
														, WeaponTraceEnd
														, ECollisionChannel::ECC_Visibility);
			// Object between barrel and BeamEndPoint?
			if (WeaponTraceHit.bBlockingHit)
				BeamEndPoint = WeaponTraceHit.Location;
			// Spawn impact particles after updating Beampoint
			if (ImpactParticles)
				UGameplayStatics::SpawnEmitterAtLocation(GetWorld(), ImpactParticles, WeaponTraceHit.Location);

			if (BeamParticles)
			{
				UParticleSystemComponent* Beam = UGameplayStatics::SpawnEmitterAtLocation(GetWorld(), BeamParticles, SocketTransform);
				if (Beam)
					Beam->SetVectorParameter(FName("Target"), BeamEndPoint);
			}
		}
	}
	
	UAnimInstance* AnimInstance = GetMesh()->GetAnimInstance();
	if (AnimInstance && HipFireMontage)
	{
		AnimInstance->Montage_Play(HipFireMontage);
		AnimInstance->Montage_JumpToSection(FName("StartFire"));
	}

}

변경 후

void AShooterCharacter::FireWeapon()
{
	UE_LOG(LogTemp, Warning, TEXT("Fire Weapon."));
	if (FireSound)
		UGameplayStatics::PlaySound2D(this, FireSound);

	const USkeletalMeshSocket* BarrelSocket = GetMesh()->GetSocketByName("Barrel");
	if (BarrelSocket)
	{
		const FTransform SocketTransform = BarrelSocket->GetSocketTransform(GetMesh());
		
		if (MuzzleFlash)
		{
			UGameplayStatics::SpawnEmitterAtLocation(GetWorld(), MuzzleFlash, SocketTransform);
		}

		FVector BeamEnd;
		bool bBeamEnd = GetBeamEndLocation(SocketTransform.GetLocation(), BeamEnd);
		if (bBeamEnd)
		{
			if (ImpactParticles)
			{
				UGameplayStatics::SpawnEmitterAtLocation(GetWorld(), ImpactParticles, BeamEnd);
			}

			UParticleSystemComponent* Beam = UGameplayStatics::SpawnEmitterAtLocation(GetWorld(), BeamParticles, SocketTransform);
			if (Beam)
			{
				Beam->SetVectorParameter(FName("Target"), BeamEnd);
			}
		}
	}
	UAnimInstance* AnimInstance = GetMesh()->GetAnimInstance();
	if (AnimInstance && HipFireMontage)
	{
		AnimInstance->Montage_Play(HipFireMontage);
		AnimInstance->Montage_JumpToSection(FName("StartFire"));
	}
}