Broken undo

include/Engine/Core/ComponentPool.h

@@ -65,6 +65,8 @@ public:
 	iterator end() const;
     size_t size() const;
 
+    std::size_t MemoryUsage() const;
+
 	//Dumps information about what the pool memory looks like right now 
 	//into an output stream (e.g. file/std::cout, anything that has an operator<<)
 	//Interpret the data in the memory as InterpretType.

include/Engine/Core/EntityWrapper.h

@@ -27,6 +27,7 @@ struct EntityWrapper
     bool HasComponent(const std::string& componentType);
     void AttachComponent(const char* componentName);
     EntityWrapper Parent();
+    EntityWrapper BaseParent();
     EntityWrapper FirstChildByName(const std::string& name);
     EntityWrapper FirstParentWithComponent(const std::string& componentType);
     EntityWrapper Clone(EntityWrapper parent = EntityWrapper::Invalid);

include/Engine/Core/MemoryPool.h

@@ -194,6 +194,11 @@ public:
 		return m_ExtraMemory.size();
 	}
 
+    std::size_t MemoryUsage() const
+    {
+        return size() * m_Stride;
+    }
+
 	//Dumps information about what the pool memory looks like right now 
 	//into an output stream (e.g. file/std::cout, anything that has an operator<<)
 	//Interpret the data in the memory as InterpretType.

include/Engine/Core/World.h

@@ -18,7 +18,7 @@ public:
     World(const World& other);
 
     // Create empty entity
-    EntityID CreateEntity(EntityID parent = 0);
+    EntityID CreateEntity(EntityID parent = EntityID_Invalid);
     // Delete entity and all components within
     void DeleteEntity(EntityID entity);
     // Check if an entity exists
@@ -50,6 +50,9 @@ public:
     // Get the textual name of an entity
     std::string GetName(EntityID entity) const;
 
+    // Get an approximate number for component pool memory usage
+    std::size_t MemoryUsage() const;
+
 private:
     EventBroker* m_EventBroker = nullptr;
     EntityID m_CurrentEntityID = 0;

include/Engine/Editor/EditorGUI.h

@@ -91,7 +91,13 @@ public:
     // Called when the user selects a widget space.
     typedef std::function<void(WidgetSpace)> OnWidgetSpace_t;
     void SetWidgetSpaceCallback(OnWidgetSpace_t f) { m_OnWidgetSpace = f; }
-
+    // Called when anything is modified making the world dirty
+    // @param EntityWrapper The entity that was changed and marked as dirty
+    typedef std::function<void(EntityWrapper)> OnDirty_t;
+    void SetDirtyCallback(OnDirty_t f) { m_OnDirty = f; }
+    // Called when the user wishes to undo
+    typedef std::function<void()> OnUndo_t;
+    void SetUndoCallback(OnUndo_t f) { m_OnUndo = f; }
 private:
     World* m_World;
     EventBroker* m_EventBroker;
@@ -132,6 +138,8 @@ private:
     OnWidgetMode_t m_OnWidgetMode = nullptr;
     OnWidgetSpace_t m_OnWidgetSpace = nullptr;
     OnEntityPaste_t m_OnEntityPaste = nullptr;
+    OnDirty_t m_OnDirty = nullptr;
+    OnUndo_t m_OnUndo = nullptr;
 
     // Events
     EventRelay<EditorGUI, Events::KeyDown> m_EKeyDown;

include/Engine/Editor/EditorSystem.h

@@ -36,6 +36,7 @@ private:
     EditorCameraInputController<EditorSystem>* m_EditorCameraInputController;
     EditorGUI* m_EditorGUI;
     EditorStats* m_EditorStats;
+    std::vector<World> m_UndoLevels;
 
     // State
     double m_LastTime = 0.f;
@@ -44,6 +45,7 @@ private:
     EditorGUI::WidgetSpace m_WidgetSpace = EditorGUI::WidgetSpace::Global;
     EntityWrapper m_Widget = EntityWrapper::Invalid;
     EntityWrapper m_CurrentSelection = EntityWrapper::Invalid;
+    bool m_SaveUndoLevel = false; // Only save undo state once per update
 
     // Utility functions
     EntityWrapper importEntity(EntityWrapper parent, boost::filesystem::path filePath);
@@ -60,6 +62,8 @@ private:
     void OnComponentAttach(EntityWrapper entity, const std::string& componentType);
     void OnComponentDelete(EntityWrapper entity, const std::string& componentType);
     void OnWidgetSpace(EditorGUI::WidgetSpace widgetSpace);
+    void OnDirty(EntityWrapper entity);
+    void OnUndo();
 
     // Events
     EventRelay<EditorSystem, Events::MousePress> m_EMousePress;

resources/Schema/Entities/Empty.xml

@@ -5,6 +5,20 @@
     <c:Transform/>
   </Components>
 
+  <Children>
+    <Entity>
+      <Components>
+        <c:Transform/>
+      </Components>
+      <Children>
+        <Entity>
+          <Components>
+            <c:Transform/>
+          </Components>
           <Children/>
+        </Entity>
+      </Children>
+    </Entity>
+  </Children>
 
 </Entity>

src/Engine/Core/ComponentPool.cpp

@@ -112,6 +112,11 @@ size_t ComponentPool::size() const
     return m_Pool.size();
 }
 
+std::size_t ComponentPool::MemoryUsage() const
+{
+    return m_Pool.MemoryUsage();
+}
+
 template <typename InterpretType /*= char*/>
 void ComponentPool::Dump() const
 {

src/Engine/Core/EntityWrapper.cpp

@@ -34,6 +34,15 @@ EntityWrapper EntityWrapper::Parent()
     }
 }
 
+EntityWrapper EntityWrapper::BaseParent()
+{
+    EntityWrapper baseParent = Parent();
+    while (baseParent.Parent().Valid()) {
+        baseParent = baseParent.Parent();
+    }
+    return baseParent;
+}
+
 EntityWrapper EntityWrapper::FirstChildByName(const std::string& name)
 {
     return firstChildByNameRecursive(name, this->ID);

src/Engine/Core/World.cpp

@@ -151,6 +151,17 @@ std::string World::GetName(EntityID entity) const
     }
 }
 
+std::size_t World::MemoryUsage() const
+{
+    std::size_t mem = 0;
+
+    for (auto& kv : m_ComponentPools) {
+        mem += kv.second->MemoryUsage();
+    }
+
+    return mem;
+}
+
 EntityID World::generateEntityID()
 {
     // TODO: Make EntityID generation smarter

src/Engine/Editor/EditorGUI.cpp

@@ -602,6 +602,15 @@ bool EditorGUI::OnKeyDown(const Events::KeyDown& e)
         m_CopyTarget = m_CurrentSelection;
     }
 
+    if (e.ModCtrl && e.KeyCode == GLFW_KEY_Z) {
+        if (m_OnUndo != nullptr) {
+            m_OnUndo();
+            if (!m_CurrentSelection.Valid()) {
+                SelectEntity(EntityWrapper::Invalid);
+            }
+        }
+    }
+
     if (e.ModCtrl && e.KeyCode == GLFW_KEY_V) {
         if (m_OnEntityPaste != nullptr) {
             EntityWrapper copy = m_OnEntityPaste(m_CopyTarget, m_CurrentSelection);
@@ -774,13 +783,13 @@ bool EditorGUI::compareCharArray(const char* c1, const char* c2)
 
 void EditorGUI::SetDirty(EntityWrapper entity)
 {
-    EntityWrapper baseParent = entity;
+    EntityWrapper baseParent = entity.BaseParent();
-    while (baseParent.Parent().Valid()) {
-        baseParent = baseParent.Parent();
-    }
     if (m_EntityFiles.find(baseParent) != m_EntityFiles.end()) {
         m_EntityFiles.at(baseParent).Dirty = true;
     }
+    if (m_OnDirty != nullptr) {
+        m_OnDirty(entity);
+    }
 }
 
 void EditorGUI::entityImport(World* world)
@@ -830,6 +839,7 @@ void EditorGUI::entityCreate(World* world, EntityWrapper parent)
             parent.World = world;
         }
         EntityWrapper newEntity = m_OnEntityCreate(parent);
+        SetDirty(newEntity);
         SelectEntity(newEntity);
     }
 }
@@ -845,9 +855,9 @@ void EditorGUI::entityDelete(EntityWrapper entity)
         if (boost::any_cast<EntityWrapper>(m_ModalData[modalName]) == entity) {
             EntityWrapper parent = entity.Parent();
             if (m_OnEntityDelete != nullptr) {
-                SetDirty(entity);
                 m_OnEntityDelete(entity);
                 m_EntityFiles.erase(entity);
+                SetDirty(parent);
             }
             if (!m_CurrentSelection.Valid()) {
                 SelectEntity(parent);
@@ -864,8 +874,8 @@ void EditorGUI::entityChangeParent(EntityWrapper entity, EntityWrapper parent)
     }
 
     if (m_OnEntityChangeParent != nullptr) {
-        SetDirty(entity);
         m_OnEntityChangeParent(entity, parent);
+        SetDirty(entity);
         LOG_DEBUG("Changed parent of %i to %i", entity.ID, parent.ID);
     }
 }

src/Engine/Editor/EditorSystem.cpp

@@ -33,6 +33,8 @@ EditorSystem::EditorSystem(SystemParams params, IRenderer* renderer, RenderFrame
     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));
     m_EditorGUI->SetWidgetSpaceCallback(std::bind(&EditorSystem::OnWidgetSpace, this, std::placeholders::_1));
+    m_EditorGUI->SetDirtyCallback(std::bind(&EditorSystem::OnDirty, this, std::placeholders::_1));
+    m_EditorGUI->SetUndoCallback(std::bind(&EditorSystem::OnUndo, this));
 
     EVENT_SUBSCRIBE_MEMBER(m_EMousePress, &EditorSystem::OnMousePress);
     EVENT_SUBSCRIBE_MEMBER(m_EWidgetDelta, &EditorSystem::OnWidgetDelta);
@@ -87,6 +89,11 @@ void EditorSystem::Update(double dt)
         glm::vec3& pos = cameraTransform["Position"];
         pos += m_EditorCameraInputController->Movement() * glm::inverse(glm::quat(ori)) * (float)actualDelta;
     }
+
+    if (m_SaveUndoLevel) {
+        m_UndoLevels.push_back(*m_World);
+        m_SaveUndoLevel = false;
+    }
 }
 
 void EditorSystem::Enable()
@@ -185,6 +192,19 @@ void EditorSystem::OnWidgetSpace(EditorGUI::WidgetSpace widgetSpace)
     m_WidgetSpace = widgetSpace;
 }
 
+void EditorSystem::OnDirty(EntityWrapper entity)
+{
+    m_SaveUndoLevel = true;
+}
+
+void EditorSystem::OnUndo()
+{
+    // The last "undo level" is always the most recent change
+    if (m_UndoLevels.size() >= 2) {
+        *m_World = m_UndoLevels.at(m_UndoLevels.size() - 2);
+    }
+}
+
 bool EditorSystem::OnMousePress(const Events::MousePress& e)
 {
     ImGuiIO& io = ImGui::GetIO();