Fix model manager. It's version stable for model manager

Core/Core/RenderEngine/ModelManager.cpp

@@ -1,5 +1,7 @@
 #include "ModelManager.hpp"
 
+#include "Log/Log.hpp"
+
 ModelManager::StaticModel::StaticModel(const std::vector<Voxel>& voxels, std::string name):
 name_(std::move(name)),
 voxels_(voxels)
@@ -30,6 +32,10 @@ ModelManager::StaticModel::~StaticModel()
     OnDestroy.Call(name_);
 }
 
+ModelManager::owner_counter::owner_counter(const owner_counter& other) : counter(other.counter.load()), model(other.model)
+{
+}
+
 unsigned int ModelManager::FNV1aHash(const char* buf)
 {	
     unsigned int h_val = 0x811c9dc5;
@@ -45,29 +51,57 @@ unsigned int ModelManager::FNV1aHash(const char* buf)
 
 void ModelManager::OnDestroySometimeModelCaller(const std::string& name)
 {
+    Log("Free model: " + name);
     OnDestroySometimeModel.Call(name);
 }
 
 ModelManager::~ModelManager()
 {
-    for (const auto& [it, model] : models)
+    for (const auto& [it, counter] : models)
     {
-        model->OnDestroy.unbind(this, &ModelManager::OnDestroySometimeModelCaller);
+        counter.model->OnDestroy.unbind(this, &ModelManager::OnDestroySometimeModelCaller);
     }
     models.clear();
 }
 
-std::shared_ptr<ModelManager::StaticModel> ModelManager::LoadModel(const std::string& name)
+ModelManager::StaticModel* ModelManager::LoadModel(const std::string& name)
 {
+    if (name.empty())
+        return nullptr;
     unsigned int hash = FNV1aHash(name.c_str());
-    auto model = models.find(hash);
-    if (model != models.cend())
-        return model->second;
+    auto counter = models.find(hash);
+    if (counter != models.cend())
+    {
+        ++counter->second.counter;
+        return counter->second.model;
+    }
 
+    Log("Load new model: " + name);
+    
     std::vector<Voxel> model_data;
     // Load model_data
-    auto newModel = std::make_shared<StaticModel>(model_data, name);
-    newModel->OnDestroy.bind(this, &ModelManager::OnDestroySometimeModelCaller);
-    models[hash] = newModel;
-    return models[hash];
+    owner_counter new_counter;
+    new_counter.counter.store(1);
+    new_counter.model = new StaticModel(model_data, name);
+    new_counter.model->OnDestroy.bind(this, &ModelManager::OnDestroySometimeModelCaller);
+    models.try_emplace(hash, new_counter);
+    
+    return new_counter.model;
+}
+
+void ModelManager::FreeModel(const std::string& name)
+{
+    if (name.empty())
+        return;
+    
+    unsigned int hash = FNV1aHash(name.c_str());
+    auto counter = models.find(hash);
+    --counter->second.counter;
+
+    StaticModel* model = counter->second.model;
+    if (counter->second.counter.load() == 0)
+    {
+        models.erase(hash);
+        delete model;
+    }
 }