Basic editor copy and paste. Doesn't actually copy the entity until you paste it.

include/Engine/Core/EntityWrapper.h

@@ -29,6 +29,7 @@ struct EntityWrapper
     EntityWrapper Parent();
     EntityWrapper FirstChildByName(const std::string& name);
     EntityWrapper FirstParentWithComponent(const std::string& componentType);
+    EntityWrapper Clone(EntityWrapper parent = EntityWrapper::Invalid);
     bool IsChildOf(EntityWrapper potentialParent);
     bool Valid() const;
 
@@ -39,6 +40,7 @@ struct EntityWrapper
 
 private:
     EntityWrapper firstChildByNameRecursive(const std::string& name, EntityID parent);
+    EntityWrapper cloneRecursive(EntityWrapper entity, EntityWrapper parent);
 };
 
 namespace std

include/Engine/Core/World.h

@@ -40,7 +40,7 @@ public:
     // Change the parent of an entity
     void SetParent(EntityID entity, EntityID parent);
     // Get children of an entity
-    const std::pair<std::unordered_multimap<EntityID, EntityID>::const_iterator, std::unordered_multimap<EntityID, EntityID>::const_iterator> GetChildren(EntityID entity);
+    const std::pair<std::unordered_multimap<EntityID, EntityID>::const_iterator, std::unordered_multimap<EntityID, EntityID>::const_iterator> GetDirectChildren(EntityID entity);
     // Get all component pools
     const std::unordered_map<std::string, ComponentPool*>& GetComponentPools() const { return m_ComponentPools; }
     // Get the entity children map

include/Engine/Editor/EditorGUI.h

@@ -73,6 +73,12 @@ public:
     // Called when the user means to rename an entity.
     typedef std::function<void(EntityWrapper, const std::string&)> OnEntityChangeName_t;
     void SetEntityChangeNameCallback(OnEntityChangeName_t f) { m_OnEntityChangeName = f; }
+    // Called when the user pastes an entity previously "copied"
+    // @param EntityWrapper The entity to copy
+    // @param EntityWrapper The entity to parent the new copy to
+    // @return The new copy of the entity
+    typedef std::function<EntityWrapper(EntityWrapper, EntityWrapper)> OnEntityPaste_t;
+    void SetEntityPasteCallback(OnEntityPaste_t f) { m_OnEntityPaste = f; }
     // Called when the user means to attach a new component to an entity.
     typedef std::function<void(EntityWrapper, const std::string&)> OnComponentAttach_t;
     void SetComponentAttachCallback(OnComponentAttach_t f) { m_OnComponentAttach = f; }
@@ -111,6 +117,7 @@ private:
     std::string m_DroppedFile = "";
     bool m_Paused = false;
     bool m_MouseLocked = false;
+    EntityWrapper m_CopyTarget = EntityWrapper::Invalid;
 
     // Callbacks
     OnEntitySelectedCallback_t m_OnEntitySelected = nullptr;
@@ -124,6 +131,7 @@ private:
     OnComponentDelete_t m_OnComponentDelete = nullptr;
     OnWidgetMode_t m_OnWidgetMode = nullptr;
     OnWidgetSpace_t m_OnWidgetSpace = nullptr;
+    OnEntityPaste_t m_OnEntityPaste = nullptr;
 
     // Events
     EventRelay<EditorGUI, Events::KeyDown> m_EKeyDown;

include/Engine/Editor/EditorSystem.h

@@ -56,6 +56,7 @@ private:
     void OnEntityDelete(EntityWrapper entity);
     void OnEntityChangeParent(EntityWrapper entity, EntityWrapper parent);
     void OnEntityChangeName(EntityWrapper entity, const std::string& name);
+    EntityWrapper OnEntityPaste(EntityWrapper entityToCopy, EntityWrapper parent);
     void OnComponentAttach(EntityWrapper entity, const std::string& componentType);
     void OnComponentDelete(EntityWrapper entity, const std::string& componentType);
     void OnWidgetSpace(EditorGUI::WidgetSpace widgetSpace);

src/Engine/Core/EntityWrapper.cpp

@@ -51,6 +51,17 @@ EntityWrapper EntityWrapper::FirstParentWithComponent(const std::string& compone
     return EntityWrapper::Invalid;
 }
 
+EntityWrapper EntityWrapper::Clone(EntityWrapper parent /*= Invalid*/)
+{
+    if (!Valid()) {
+        return EntityWrapper::Invalid;
+    }
+
+    EntityWrapper clone = cloneRecursive(*this, EntityWrapper::Invalid);
+    this->World->SetParent(clone.ID, parent.ID);
+    return clone;
+}
+
 bool EntityWrapper::IsChildOf(EntityWrapper potentialParent)
 {
     EntityWrapper entity = *this;
@@ -111,7 +122,7 @@ EntityWrapper EntityWrapper::firstChildByNameRecursive(const std::string& name,
         return EntityWrapper::Invalid;
     }
 
-    auto itPair = this->World->GetChildren(parent);
+    auto itPair = this->World->GetDirectChildren(parent);
     if (itPair.first == itPair.second) {
         return EntityWrapper::Invalid;
     }
@@ -131,3 +142,27 @@ EntityWrapper EntityWrapper::firstChildByNameRecursive(const std::string& name,
     return EntityWrapper::Invalid;
 }
 
+EntityWrapper EntityWrapper::cloneRecursive(EntityWrapper entity, EntityWrapper parent)
+{
+    EntityWrapper clone = EntityWrapper(entity.World, entity.World->CreateEntity(parent.ID));
+    entity.World->SetName(clone.ID, entity.Name());
+
+    // Clone components
+    for (auto& kv : entity.World->GetComponentPools()) {
+        if (kv.second->KnowsEntity(entity.ID)) {
+            ComponentWrapper c1 = kv.second->GetByEntity(entity.ID);
+            ComponentWrapper c2 = entity.World->AttachComponent(clone.ID, kv.first);
+            c1.Copy(c2);
+        }
+    }
+
+    // Clone children
+    auto children = entity.World->GetDirectChildren(entity.ID);
+    for (auto it = children.first; it != children.second; ++it) {
+        EntityWrapper child(entity.World, it->second);
+        cloneRecursive(child, clone);
+    }
+      
+    return clone;
+}
+

src/Engine/Core/World.cpp

@@ -127,7 +127,7 @@ void World::SetParent(EntityID entity, EntityID parent)
     m_EntityChildren.insert(std::make_pair(parent, entity));
 }
 
-const std::pair<std::unordered_multimap<EntityID, EntityID>::const_iterator, std::unordered_multimap<EntityID, EntityID>::const_iterator> World::GetChildren(EntityID entity)
+const std::pair<std::unordered_multimap<EntityID, EntityID>::const_iterator, std::unordered_multimap<EntityID, EntityID>::const_iterator> World::GetDirectChildren(EntityID entity)
 {
     return m_EntityChildren.equal_range(entity);
 }

src/Engine/Editor/EditorGUI.cpp

@@ -598,6 +598,19 @@ bool EditorGUI::OnKeyDown(const Events::KeyDown& e)
         entityImport(m_World);
     }
 
+    if (e.ModCtrl && e.KeyCode == GLFW_KEY_C) {
+        m_CopyTarget = m_CurrentSelection;
+    }
+
+    if (e.ModCtrl && e.KeyCode == GLFW_KEY_V) {
+        if (m_OnEntityPaste != nullptr) {
+            EntityWrapper copy = m_OnEntityPaste(m_CopyTarget, m_CurrentSelection);
+            if (copy != EntityWrapper::Invalid) {
+                SelectEntity(copy);
+            }
+        }
+    }
+
     if (e.KeyCode == GLFW_KEY_DELETE) {
         if (m_CurrentSelection.Valid()) {
             entityDelete(m_CurrentSelection);

src/Engine/Editor/EditorSystem.cpp

@@ -28,6 +28,7 @@ EditorSystem::EditorSystem(SystemParams params, IRenderer* renderer, RenderFrame
     m_EditorGUI->SetEntityDeleteCallback(std::bind(&EditorSystem::OnEntityDelete, this, std::placeholders::_1));
     m_EditorGUI->SetEntityChangeParentCallback(std::bind(&EditorSystem::OnEntityChangeParent, this, std::placeholders::_1, std::placeholders::_2));
     m_EditorGUI->SetEntityChangeNameCallback(std::bind(&EditorSystem::OnEntityChangeName, this, std::placeholders::_1, std::placeholders::_2));
+    m_EditorGUI->SetEntityPasteCallback(std::bind(&EditorSystem::OnEntityPaste, this, std::placeholders::_1, std::placeholders::_2));
     m_EditorGUI->SetComponentAttachCallback(std::bind(&EditorSystem::OnComponentAttach, this, std::placeholders::_1, std::placeholders::_2));
     m_EditorGUI->SetComponentDeleteCallback(std::bind(&EditorSystem::OnComponentDelete, this, std::placeholders::_1, std::placeholders::_2));
     m_EditorGUI->SetWidgetModeCallback(std::bind(&EditorSystem::setWidgetMode, this, std::placeholders::_1));
@@ -160,6 +161,11 @@ void EditorSystem::OnEntityChangeName(EntityWrapper entity, const std::string& n
     }
 }
 
+EntityWrapper EditorSystem::OnEntityPaste(EntityWrapper entityToCopy, EntityWrapper parent)
+{
+    return entityToCopy.Clone(parent);
+}
+
 void EditorSystem::OnComponentAttach(EntityWrapper entity, const std::string& componentType)
 {
     if (entity.Valid()) {

src/Engine/Network/Server.cpp

@@ -183,7 +183,7 @@ void Server::addInputCommandsToPacket(Packet& packet)
 
 void Server::addPlayersToPacket(Packet & packet, EntityID entityID)
 {
-    auto itPair = m_World->GetChildren(entityID);
+    auto itPair = m_World->GetDirectChildren(entityID);
     std::unordered_map<std::string, ComponentPool*> worldComponentPools = m_World->GetComponentPools();
     // Loop through every child
     for (auto it = itPair.first; it != itPair.second; it++) {
@@ -233,7 +233,7 @@ void Server::addPlayersToPacket(Packet & packet, EntityID entityID)
 
 void Server::addChildrenToPacket(Packet & packet, EntityID entityID)
 {
-    auto itPair = m_World->GetChildren(entityID);
+    auto itPair = m_World->GetDirectChildren(entityID);
     std::unordered_map<std::string, ComponentPool*> worldComponentPools = m_World->GetComponentPools();
     // Loop through every child
     for (auto it = itPair.first; it != itPair.second; it++) {

src/Game/Systems/SpawnerSystem.cpp

@@ -36,7 +36,7 @@ EntityWrapper SpawnerSystem::Spawn(EntityWrapper spawner, EntityWrapper parent /
     }
 
     // Find any SpawnPoints existing as children of spawner
-    auto children = spawner.World->GetChildren(spawner.ID);
+    auto children = spawner.World->GetDirectChildren(spawner.ID);
     std::vector<EntityWrapper> spawnPoints;
     for (auto kv = children.first; kv != children.second; ++kv) {
         const EntityID& child = kv->second;