Added World DeleteEntity, HasComponent and GetEntityChildren

include/Engine/Core/World.h

@@ -14,11 +14,15 @@ public:
 
     // Create empty entity
     EntityID CreateEntity(EntityID parent = 0);
+    // Delete entity and all components within
+    void DeleteEntity(EntityID entity);
 
     // Register a component type and allocate space for it
     void RegisterComponent(ComponentInfo& ci);
     // Attach a component to an entity and fill it with default values
     ComponentWrapper AttachComponent(EntityID entity, std::string componentType);
+    // Check if an entity has a component
+    bool HasComponent(EntityID entity, std::string componentType);
     // Get a component of an entity
     ComponentWrapper GetComponent(EntityID entity, std::string componentType);
     // Delete a component off an entity
@@ -29,6 +33,8 @@ public:
     EntityID GetParent(EntityID entity);
     // Get all component pools
     const std::unordered_map<std::string, ComponentPool*>& GetComponentPools() const { return m_ComponentPools; }
+    // Get the entity children map
+    const std::unordered_multimap<EntityID, EntityID>& GetEntityChildren() const { return m_EntityChildren; }
 
 private:
     EntityID m_CurrentEntityID = 1;

src/Engine/Core/World.cpp

@@ -11,12 +11,43 @@ EntityID World::CreateEntity(EntityID parent /*= 0*/)
 {
     EntityID newEntity = generateEntityID();
     m_EntityParents[newEntity] = parent;
-    if (parent != 0) {
-        m_EntityChildren.insert(std::make_pair(parent, newEntity));
-    }
+    m_EntityChildren.insert(std::make_pair(parent, newEntity));
     return newEntity;
 }
 
+
+void World::DeleteEntity(EntityID entity)
+{
+    // Delete components
+    for (auto& pair : m_ComponentPools) {
+        auto& pool = pair.second;
+        if (pool->KnowsEntity(entity)) {
+            auto& c = pool->GetByEntity(entity);
+            pool->Delete(c);
+        }
+    }
+
+    // Loop through children
+    std::vector<EntityID> childrenToDelete;
+    auto children = m_EntityChildren.equal_range(entity);
+    for (auto it = children.first; it != children.second; ++it) {
+        childrenToDelete.push_back(it->second);
+    }
+    for (auto& child : childrenToDelete) {
+        DeleteEntity(child);
+    }
+
+    EntityID parent = m_EntityParents.at(entity);
+    m_EntityParents.erase(entity);
+    auto parentChildren = m_EntityChildren.equal_range(parent);
+    for (auto it = parentChildren.first; it != parentChildren.second; ++it) {
+        if (it->second == entity) {
+            m_EntityChildren.erase(it);
+            break;
+        }
+    }
+}
+
 void World::RegisterComponent(ComponentInfo& ci)
 {
     m_ComponentPools[ci.Name] = new ComponentPool(ci);
@@ -35,6 +66,13 @@ ComponentWrapper World::AttachComponent(EntityID entity, std::string componentTy
     return c;
 }
 
+
+bool World::HasComponent(EntityID entity, std::string componentType)
+{
+    ComponentPool* pool = m_ComponentPools.at(componentType);
+    return pool->KnowsEntity(entity);
+}
+
 ComponentWrapper World::GetComponent(EntityID entity, std::string componentType)
 {
     ComponentPool* pool = m_ComponentPools.at(componentType);