Section 10: Outline and Glow Effects - Lecture 192

Assigning the Icon Delegate

Source/Shooter/Item.cpp

@@ -519,6 +519,8 @@ void AItem::FinishInterping()
 		// Subtract 1 from the Item Count of the interp location struct
 		Character->IncrementInterpLocItemCount(InterpLocIndex, -1);
 		Character->GetPickupItem(this);
+
+		Character->UnhighlightInventorySlot();
 	}
 	// Set scale back to normal
 	SetActorScale3D(FVector(1.f));

Source/Shooter/ShooterCharacter.cpp

@@ -74,7 +74,9 @@ AShooterCharacter::AShooterCharacter() :
 	bShouldPlayPickupSound(true),
 	bShouldPlayEquipSound(true),
 	PickupSoundResetTime(0.2f),
-	EquipSoundResetTime(0.2f)
+	EquipSoundResetTime(0.2f),
+	// Icon animation property
+	HighlightedSlot(-1)
 {
  	// 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;
@@ -416,7 +418,7 @@ void AShooterCharacter::ExchangeInventoryItems(int32 CurrentItemIndex, int32 New
 {
 	if (CurrentItemIndex == NewItemIndex
 		|| NewItemIndex >= Inventory.Num()
-		|| CombatState != ECombatState::ECS_Unoccupied)
+		|| (CombatState != ECombatState::ECS_Unoccupied && CombatState != ECombatState::ECS_Equipping))
 		return;
 
 	auto OldEquippedWeapon = EquippedWeapon;
@@ -437,6 +439,41 @@ void AShooterCharacter::ExchangeInventoryItems(int32 CurrentItemIndex, int32 New
 	NewWeapon->PlayEquipSound(true);
 }
 
+int32 AShooterCharacter::GetEmptyInventorySlot()
+{
+	for (int32 i = 0; i < Inventory.Num(); ++i)
+	{
+		if (Inventory[i] == nullptr)
+			return i;
+	}
+
+	if (Inventory.Num() < INVENTORY_CAPACITY)
+	{
+		return Inventory.Num();
+	}
+
+	return -1; // Inventory full
+}
+
+void AShooterCharacter::HighlightInventorySlot()
+{
+	const int32 EmptySlot{ GetEmptyInventorySlot() };
+	if (EmptySlot != -1)
+	{
+		HighlightIconDelegate.Broadcast(EmptySlot, true);
+		HighlightedSlot = EmptySlot;
+	}
+}
+
+void AShooterCharacter::UnhighlightInventorySlot()
+{
+	if (HighlightedSlot != -1)
+	{
+		HighlightIconDelegate.Broadcast(HighlightedSlot, false);
+		HighlightedSlot = -1;
+	}
+}
+
 int32 AShooterCharacter::GetInterpLocationIndex()
 {
 	int32 LowestIndex = 1;
@@ -766,14 +803,19 @@ void AShooterCharacter::TraceForItems()
 		{
 			// If an item was being looked at from last frame, we should hide its widget
 			if (OldTraceHitItem != TraceHitItem)
+			{
+				UnhighlightInventorySlot();
 				SetItemPickupWidgetVisibility(OldTraceHitItem, false);
-			
-			// Show the new item's widget
-			OldTraceHitItem = TraceHitItem;
+			}
 
 			if (TraceHitItem && TraceHitItem->GetItemState() == EItemState::EIS_EquipInterping)
 				TraceHitItem = nullptr;
 
+			const auto TraceHitWeapon = Cast<AWeapon>(TraceHitItem);
+			if (TraceHitWeapon && HighlightedSlot == -1)
+				HighlightInventorySlot();
+
+			// Show the new item's widget
 			SetItemPickupWidgetVisibility(TraceHitItem, true);
 
 			if (Inventory.Num() >= INVENTORY_CAPACITY)
@@ -785,15 +827,21 @@ void AShooterCharacter::TraceForItems()
 			{
 				TraceHitItem->SetCharacterInventoryFull(false);
 			}
+
+			OldTraceHitItem = TraceHitItem;
 		}
 		else if (OldTraceHitItem) // Hide widget for the item from last frame
 		{
+			UnhighlightInventorySlot();
+
 			SetItemPickupWidgetVisibility(OldTraceHitItem, false);
 			OldTraceHitItem = nullptr;
 		}
 	}
 	else if (TraceHitItem) // Hide widget for the item from last frame
 	{
+		UnhighlightInventorySlot();
+
 		SetItemPickupWidgetVisibility(TraceHitItem, false);
 		TraceHitItem = nullptr;
 	}
@@ -822,7 +870,7 @@ AWeapon* AShooterCharacter::SpawnDefaultWeapon()
 	return nullptr;
 }
 
-void AShooterCharacter::EquipWeapon(AWeapon* WeaponToEquip)
+void AShooterCharacter::EquipWeapon(AWeapon* WeaponToEquip, bool bSwapping)
 {
 	// Get the hand socket
 	const USkeletalMeshSocket* HandSocket = GetMesh()->GetSocketByName(FName("RightHandSocket"));
@@ -837,7 +885,7 @@ void AShooterCharacter::EquipWeapon(AWeapon* WeaponToEquip)
 			// -1 == no EquippedWeapon yet. No need to reverse the icon animation
 			EquipItemDelegate.Broadcast(-1, WeaponToEquip->GetSlotIndex());
 		}
-		else
+		else if (!bSwapping)
 		{
 			EquipItemDelegate.Broadcast(EquippedWeapon->GetSlotIndex(), WeaponToEquip->GetSlotIndex());
 		}
@@ -886,7 +934,7 @@ void AShooterCharacter::SwapWeapon(AWeapon* WeaponToSwap)
 	}
 
 	DropWeapon();
-	EquipWeapon(WeaponToSwap);
+	EquipWeapon(WeaponToSwap, true);
 }
 
 void AShooterCharacter::InitializeAmmoMap()

Source/Shooter/ShooterCharacter.h

@@ -45,6 +45,8 @@ struct FInterpLocation
 
 DECLARE_DYNAMIC_MULTICAST_DELEGATE_TwoParams(FEquipItemDelegate, int32, CurrentSlotIndex, int32, NewSlotIndex);
 
+DECLARE_DYNAMIC_MULTICAST_DELEGATE_TwoParams(FHighlightIconDelegate, int32, SlotIndex, bool, bStartAnimation);
+
 
 UCLASS()
 class SHOOTER_API AShooterCharacter : public ACharacter
@@ -140,7 +142,7 @@ protected:
 	AWeapon* SpawnDefaultWeapon();
 
 	/* Takes a weapon and attaches it to the mesh */
-	void EquipWeapon(AWeapon* WeaponToEquip);
+	void EquipWeapon(AWeapon* WeaponToEquip, bool bSwapping = false);
 
 	/** Detach weapon and let it fall to the ground */
 	void DropWeapon();
@@ -210,6 +212,10 @@ protected:
 	
 	void ExchangeInventoryItems(int32 CurrentItemIndex, int32 NewItemIndex);
 
+	int32 GetEmptyInventorySlot();
+
+	void HighlightInventorySlot();
+
 private:
 	UPROPERTY(VisibleAnywhere, BlueprintReadOnly, Category = Camera, meta = (AllowPrivateAccess = true))
 	USpringArmComponent* CameraBoom;
@@ -477,6 +483,14 @@ private:
 	UPROPERTY(BlueprintAssignable, Category = Delegates, meta = (AllowPrivateAccess = true))
 	FEquipItemDelegate EquipItemDelegate;
 
+	/** Delegate for sending slot information for playing the icon animation */
+	UPROPERTY(BlueprintAssignable, Category = Delegates, meta = (AllowPrivateAccess = true))
+	FHighlightIconDelegate HighlightIconDelegate;
+
+	/** The index for the currently highlighted slot */
+	UPROPERTY(VisibleAnywhere, BlueprintReadOnly, Category = Inventory, meta = (AllowPrivateAccess = true))
+	int32 HighlightedSlot;
+
 public:
 	/* Returns CameraBoom SubObject */
 	FORCEINLINE USpringArmComponent* GetCameraBoom() const { return CameraBoom; }
@@ -515,4 +529,6 @@ public:
 
 	void StartPickupSoundTimer();
 	void StartEquipSoundTimer();
+
+	void UnhighlightInventorySlot();
 };