Sdk/Entity: Add DropComponent method

ChangeLog.md

@@ -292,6 +292,7 @@ Nazara Development Kit:
 - ⚠️ Console now supports text color in history
 - Added World::CloneEntity overload taking an EntityHandle const reference, allowing to copy entities from other worlds
 - Fixed PhysicsComponent2D copy not copying physics attributes
+- Added Entity::DropComponent which detaches a component without necessarily destroying it
 
 # 0.4:
 

SDK/include/NDK/Entity.hpp

@@ -43,6 +43,10 @@ namespace Ndk
 			const EntityHandle& Clone() const;
 
 			inline void Disable();
+
+			std::unique_ptr<BaseComponent> DropComponent(ComponentIndex index);
+			template<typename ComponentType> std::unique_ptr<BaseComponent> DropComponent();
+
 			void Enable(bool enable = true);
 
 			inline BaseComponent& GetComponent(ComponentIndex index);
@@ -83,8 +87,6 @@ namespace Ndk
 			void Create();
 			void Destroy();
 
-			void DestroyComponent(ComponentIndex index);
-
 			inline Nz::Bitset<>& GetRemovedComponentBits();
 
 			inline void RegisterEntityList(EntityList* list);

SDK/include/NDK/Entity.inl

@@ -64,6 +64,15 @@ namespace Ndk
 	* \remark Produces a NazaraAssert if component is not available in this entity
 	*/
 
+	template<typename ComponentType>
+	std::unique_ptr<BaseComponent> Entity::DropComponent()
+	{
+		static_assert(std::is_base_of<BaseComponent, ComponentType>::value, "ComponentType is not a component");
+
+		ComponentIndex index = GetComponentIndex<ComponentType>();
+		return DropComponent(index);
+	}
+
 	template<typename ComponentType>
 	ComponentType& Entity::GetComponent()
 	{

SDK/src/NDK/Entity.cpp

@@ -97,6 +97,36 @@ namespace Ndk
 		return m_world->CloneEntity(m_id);
 	}
 
+	/*!
+	* \brief Detaches a component from the entity
+	* \return An owning pointer to the component
+	*
+	* Instantly detaches a component from the entity and returns it, allowing to attach it to another entity
+	*
+	* \remark Unlike RemoveComponent, this function instantly removes the component
+	*/
+	std::unique_ptr<BaseComponent> Entity::DropComponent(ComponentIndex index)
+	{
+		if (!HasComponent(index))
+			return nullptr;
+
+		// We get the component and we alert existing components of the deleted one
+		std::unique_ptr<BaseComponent> component = std::move(m_components[index]);
+		m_components[index].reset();
+
+		for (std::size_t i = m_componentBits.FindFirst(); i != m_componentBits.npos; i = m_componentBits.FindNext(i))
+		{
+			if (i != index)
+				m_components[i]->OnComponentDetached(*component);
+		}
+		m_componentBits.Reset(index);
+		m_removedComponentBits.UnboundedReset(index);
+
+		component->SetEntity(nullptr);
+
+		return component;
+	}
+
 	/*!
 	* \brief Enables the entity
 	*
@@ -208,32 +238,4 @@ namespace Ndk
 
 		m_valid = false;
 	}
-
-	/*!
-	* \brief Destroys a component by index
-	*
-	* \param index Index of the component
-	*
-	* \remark If component is not available, no action is performed
-	*/
-
-	void Entity::DestroyComponent(ComponentIndex index)
-	{
-		if (HasComponent(index))
-		{
-			// We get the component and we alert existing components of the deleted one
-			BaseComponent& component = *m_components[index].get();
-			for (std::size_t i = m_componentBits.FindFirst(); i != m_componentBits.npos; i = m_componentBits.FindNext(i))
-			{
-				if (i != index)
-					m_components[i]->OnComponentDetached(component);
-			}
-
-			component.SetEntity(nullptr);
-
-			m_components[index].reset();
-			m_componentBits.Reset(index);
-		}
-	}
-
 }

SDK/src/NDK/World.cpp

@@ -249,8 +249,7 @@ namespace Ndk
 
 			Nz::Bitset<>& removedComponents = entity->GetRemovedComponentBits();
 			for (std::size_t j = removedComponents.FindFirst(); j != m_dirtyEntities.back.npos; j = removedComponents.FindNext(j))
-				entity->DestroyComponent(static_cast<Ndk::ComponentIndex>(j));
-			removedComponents.Reset();
+				entity->DropComponent(static_cast<Ndk::ComponentIndex>(j));
 
 			for (auto& system : m_orderedSystems)
 			{