From 967bf6b161b7082e4e68f4a79330039cfc9c5569 Mon Sep 17 00:00:00 2001
From: Lauchmelder <robert.trololo@gmail.com>
Date: Sun, 26 Dec 2021 19:38:22 +0100
Subject: [PATCH] reworked objectmanager

---
 CMakeLists.txt                     |  3 +-
 include/lol/Shader.hpp             |  2 -
 include/lol/Texture.hpp            |  2 -
 include/lol/VertexArrayObject.hpp  |  3 --
 include/lol/util/Exceptions.hpp    | 16 +++++++
 include/lol/util/ObjectManager.hpp | 69 +++++++++---------------------
 src/ObjectManager.cpp              | 33 ++++++++++++++
 7 files changed, 71 insertions(+), 57 deletions(-)
 create mode 100644 include/lol/util/Exceptions.hpp
 create mode 100644 src/ObjectManager.cpp

diff --git a/CMakeLists.txt b/CMakeLists.txt
index b80c26f..6bf3c1d 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -23,7 +23,8 @@ add_library(lol STATIC
 	"src/Buffer.cpp" 
 	"src/buffers/VertexBuffer.cpp" 
 	"src/buffers/ElementBuffer.cpp"
-	"src/Image.cpp")
+	"src/Image.cpp"
+	"src/ObjectManager.cpp")
 
 target_include_directories(lol PUBLIC 
 	${GLM_INCLUDE_DIRS}
diff --git a/include/lol/Shader.hpp b/include/lol/Shader.hpp
index 31ea750..8c28e96 100644
--- a/include/lol/Shader.hpp
+++ b/include/lol/Shader.hpp
@@ -82,6 +82,4 @@ namespace lol
 	private:
 		unsigned int id;
 	};
-
-	typedef ObjectManager<Shader> ShaderManager;
 }
\ No newline at end of file
diff --git a/include/lol/Texture.hpp b/include/lol/Texture.hpp
index 5806ece..7e627f1 100644
--- a/include/lol/Texture.hpp
+++ b/include/lol/Texture.hpp
@@ -28,8 +28,6 @@ namespace lol
 		unsigned int id;
 	};
 
-	typedef ObjectManager<Texture> TextureManager;
-
 
 	class Texture2D : public Texture
 	{
diff --git a/include/lol/VertexArrayObject.hpp b/include/lol/VertexArrayObject.hpp
index 1a99230..2c5cd9f 100644
--- a/include/lol/VertexArrayObject.hpp
+++ b/include/lol/VertexArrayObject.hpp
@@ -36,7 +36,4 @@ namespace lol
 		std::shared_ptr<ElementBuffer> elementBuffer;
 	};
 
-	// Object manager for managing said shared pointers
-	typedef ObjectManager<VertexArray> VAOManager;
-
 }
\ No newline at end of file
diff --git a/include/lol/util/Exceptions.hpp b/include/lol/util/Exceptions.hpp
new file mode 100644
index 0000000..4fd9ad1
--- /dev/null
+++ b/include/lol/util/Exceptions.hpp
@@ -0,0 +1,16 @@
+#pragma once
+
+#include <stdexcept>
+
+#define TYPENAME(x) #x
+
+namespace lol
+{
+    class ObjectNotFoundException : public std::runtime_error
+    {
+    public:
+        ObjectNotFoundException(unsigned int id) :
+            std::runtime_error("Failed to Get() object with ID " + std::to_string(id) + " from ObjectManager. It does not exist.")
+        { }
+    };
+}
\ No newline at end of file
diff --git a/include/lol/util/ObjectManager.hpp b/include/lol/util/ObjectManager.hpp
index 442418f..fed00b2 100644
--- a/include/lol/util/ObjectManager.hpp
+++ b/include/lol/util/ObjectManager.hpp
@@ -3,6 +3,9 @@
 #include <map>
 #include <memory>
 
+#include <lol/util/NonCopyable.hpp>
+#include <lol/util/Exceptions.hpp>
+
 namespace lol
 {
 
@@ -17,75 +20,43 @@ namespace lol
 	 * As a consequence, even if no objects are using an object stored in here it will continue to
 	 * exist.
 	 */
-	template<typename Type>
 	class ObjectManager : public NonCopyable
 	{
 	public:
-		static ObjectManager<Type>& GetInstance()
-		{
-			static ObjectManager<Type> instance;
-			return instance;
-		}
+		ObjectManager() {}
 
-		/**
-		 * Add new (existing) object to manager
-		 */
-		inline void Register(unsigned int id, const std::shared_ptr<Type>& obj)
+		template<typename T, typename... Args>
+		std::shared_ptr<T> Create(unsigned int id, Args... args)
 		{
-			objects.insert(std::make_pair(id, obj));
+			std::shared_ptr<T> object = std::make_shared<T>(args...);
+			objects.insert({id, object});
+
+			return object;
 		}
 
 		/**
 		 * Remove object from manager
 		 */
-		inline void Delete(unsigned int id)
-		{
-			objects.erase(id);
-		}
+		void Delete(unsigned int id);
 
 		/**
 		 * Retrieve object from manager
 		 */
-		inline std::shared_ptr<Type> Get(unsigned int id)
+		std::shared_ptr<void> Get(unsigned int id);
+
+		template<typename T>
+		std::shared_ptr<T> Get(unsigned int id)
 		{
-			auto it = objects.find(id);
 
-			if (it == objects.end())
-				return nullptr;
-
-			return it->second;
+			std::shared_ptr<void> object = Get(id);
+			return std::static_pointer_cast<T>(object);
 		}
 
-		inline void CleanupUnused()
-		{
-			for(auto& [key, val] : objects)
-			{
-				if (val.use_count() < 3)
-					objects.erase(key);
-			}
-		}
-
-		inline void Cleanup()
-		{
-			objects.clear();
-		}
-
-		inline void Return(unsigned int id)
-		{
-			auto it = objects.find(id);
-
-			if (it == objects.end())
-				return;
-
-			if (it->second.use_count() < 3)	// I hope I don't forget about this if I ever go multithreaded
-				objects.erase(it);
-		}
+		void ClearUnused();
+		void Clear();
 
 	private:
-		ObjectManager() {}
-
-	private:
-		std::map<unsigned int, std::shared_ptr<Type>> objects;
+		std::map<unsigned int, std::shared_ptr<void>> objects;
 	};
 
 }
\ No newline at end of file
diff --git a/src/ObjectManager.cpp b/src/ObjectManager.cpp
new file mode 100644
index 0000000..b05da61
--- /dev/null
+++ b/src/ObjectManager.cpp
@@ -0,0 +1,33 @@
+#include <lol/util/ObjectManager.hpp>
+
+namespace lol
+{
+    std::shared_ptr<void> ObjectManager::Get(unsigned int id)
+    {
+        auto it = objects.find(id);
+
+        if(it == objects.end())
+            throw ObjectNotFoundException(id);
+
+        return it->second;
+    }
+
+    void ObjectManager::Delete(unsigned int id)
+    {
+        objects.erase(id);
+    }
+
+    void ObjectManager::ClearUnused()
+    {
+        for(const auto& [key, value] : objects)
+        {
+            if(value.unique())
+                objects.erase(key);
+        }
+    }
+
+	void ObjectManager::Clear()
+    {
+        objects.clear();
+    }
+}
\ No newline at end of file