11 files changed, 44 insertions, 47 deletions
diff --git a/src/crepe/api/CMakeLists.txt b/src/crepe/api/CMakeLists.txt
index c3e0b37..50c51ed 100644
--- a/src/crepe/api/CMakeLists.txt
+++ b/src/crepe/api/CMakeLists.txt
@@ -12,7 +12,6 @@ target_sources(crepe PUBLIC
 	SaveManager.cpp
 	Config.cpp
 	Metadata.cpp
-	Scene.cpp
 	SceneManager.cpp
 	Camera.cpp
 	Animator.cpp
diff --git a/src/crepe/api/Config.h b/src/crepe/api/Config.h
index 13eabd1..0c9d116 100644
--- a/src/crepe/api/Config.h
+++ b/src/crepe/api/Config.h
@@ -11,19 +11,18 @@ namespace crepe {
  * modified *before* execution is handed over from the game programmer to the engine (i.e. the
  * main loop is started).
  */
-class Config {
+class Config final {
 public:
 	//! Retrieve handle to global Config instance
 	static Config & get_instance();
 
 private:
 	Config() = default;
-
-	// singleton
-	Config(const Config &) = delete;
-	Config(Config &&) = delete;
-	Config & operator=(const Config &) = delete;
-	Config & operator=(Config &&) = delete;
+	~Config() = default;
+	Config(const Config &) = default;
+	Config(Config &&) = default;
+	Config & operator=(const Config &) = default;
+	Config & operator=(Config &&) = default;
 
 public:
 	//! Logging-related settings
diff --git a/src/crepe/api/LoopManager.cpp b/src/crepe/api/LoopManager.cpp
index a64366f..7edf4d1 100644
--- a/src/crepe/api/LoopManager.cpp
+++ b/src/crepe/api/LoopManager.cpp
@@ -57,7 +57,7 @@ void LoopManager::loop() {
 void LoopManager::setup() {
 	this->game_running = true;
 	LoopTimer::get_instance().start();
-	LoopTimer::get_instance().set_fps(60);
+	LoopTimer::get_instance().set_fps(200);
 }
 
 void LoopManager::render() {
diff --git a/src/crepe/api/LoopTimer.cpp b/src/crepe/api/LoopTimer.cpp
index a9800b7..15a0e3a 100644
--- a/src/crepe/api/LoopTimer.cpp
+++ b/src/crepe/api/LoopTimer.cpp
@@ -47,7 +47,7 @@ double LoopTimer::get_fixed_delta_time() const { return this->fixed_delta_time.c
 void LoopTimer::set_fps(int fps) {
 	this->fps = fps;
 	// target time per frame in seconds
-	this->frame_target_time = std::chrono::seconds(1) / fps;
+	this->frame_target_time = std::chrono::duration<double>(1.0) / fps;
 }
 
 int LoopTimer::get_fps() const { return this->fps; }
diff --git a/src/crepe/api/LoopTimer.h b/src/crepe/api/LoopTimer.h
index f277d7b..9393439 100644
--- a/src/crepe/api/LoopTimer.h
+++ b/src/crepe/api/LoopTimer.h
@@ -130,9 +130,9 @@ private:
 	//! Delta time for the current frame in seconds
 	std::chrono::duration<double> delta_time{0.0};
 	//! Target time per frame in seconds
-	std::chrono::duration<double> frame_target_time = std::chrono::seconds(1) / fps;
+	std::chrono::duration<double> frame_target_time = std::chrono::duration<double>(1.0) / fps;
 	//! Fixed delta time for fixed updates in seconds
-	std::chrono::duration<double> fixed_delta_time = std::chrono::seconds(1) / 50;
+	std::chrono::duration<double> fixed_delta_time = std::chrono::duration<double>(1.0) / 50.0;
 	//! Total elapsed game time in seconds
 	std::chrono::duration<double> elapsed_time{0.0};
 	//! Total elapsed time for fixed updates in seconds
diff --git a/src/crepe/api/Scene.cpp b/src/crepe/api/Scene.cpp
deleted file mode 100644
index 849945e..0000000
--- a/src/crepe/api/Scene.cpp
+++ /dev/null
@@ -1,5 +0,0 @@
-#include "Scene.h"
-
-using namespace crepe;
-
-Scene::Scene(ComponentManager & mgr) : component_manager(mgr) {}
diff --git a/src/crepe/api/Scene.h b/src/crepe/api/Scene.h
index 869bf6f..f6fdb2a 100644
--- a/src/crepe/api/Scene.h
+++ b/src/crepe/api/Scene.h
@@ -2,6 +2,8 @@
 
 #include <string>
 
+#include "../util/OptionalRef.h"
+
 namespace crepe {
 
 class SceneManager;
@@ -15,11 +17,8 @@ class ComponentManager;
  */
 class Scene {
 protected:
-	//TODO: Use Loek's custom reference class to set ComponentManger via SceneManager instead of via constructor
-	/**
-	 * \param mgr  Reference to the ComponentManager
-	 */
-	Scene(ComponentManager & mgr);
+	// NOTE: This must be the only constructor on Scene, see "Late references" below
+	Scene() = default;
 	//! SceneManager instances Scene
 	friend class SceneManager;
 
@@ -36,8 +35,20 @@ public:
 	virtual std::string get_name() const = 0;
 
 protected:
+	/**
+	 * \name Late references
+	 * 
+	 * These references are set by SceneManager immediately after calling the constructor of Scene.
+	 *
+	 * \note Scene must have a constructor without arguments so the game programmer doesn't need to
+	 * manually add `using Scene::Scene` to their concrete scene class, if they want to add a
+	 * constructor with arguments (e.g. for passing references to their own concrete Scene classes).
+	 *
+	 * \{
+	 */
 	//! Reference to the ComponentManager
-	ComponentManager & component_manager;
+	OptionalRef<ComponentManager> component_manager;
+	//! \}
 };
 
 } // namespace crepe
diff --git a/src/crepe/api/SceneManager.h b/src/crepe/api/SceneManager.h
index 45ba668..f6f62cd 100644
--- a/src/crepe/api/SceneManager.h
+++ b/src/crepe/api/SceneManager.h
@@ -26,8 +26,8 @@ public:
 	 *
 	 * \tparam T  Type of concrete scene
 	 */
-	template <typename T>
-	void add_scene();
+	template <typename T, typename... Args>
+	void add_scene(Args &&... args);
 	/**
 	 * \brief Set the next scene
 	 *
diff --git a/src/crepe/api/SceneManager.hpp b/src/crepe/api/SceneManager.hpp
index 94e5946..5c8e417 100644
--- a/src/crepe/api/SceneManager.hpp
+++ b/src/crepe/api/SceneManager.hpp
@@ -4,13 +4,17 @@
 
 namespace crepe {
 
-template <typename T>
-void SceneManager::add_scene() {
+template <typename T, typename... Args>
+void SceneManager::add_scene(Args &&... args) {
 	using namespace std;
 	static_assert(is_base_of<Scene, T>::value, "T must be derived from Scene");
 
-	Scene * scene = new T(this->component_manager);
-	this->scenes.emplace_back(unique_ptr<Scene>(scene));
+	Scene * scene = new T(std::forward<Args>(args)...);
+	unique_ptr<Scene> unique_scene(scene);
+
+	unique_scene->component_manager = this->component_manager;
+
+	this->scenes.emplace_back(std::move(unique_scene));
 
 	// The first scene added, is the one that will be loaded at the beginning
 	if (next_scene.empty()) {
diff --git a/src/crepe/api/Texture.cpp b/src/crepe/api/Texture.cpp
index 9be9421..264d7b1 100644
--- a/src/crepe/api/Texture.cpp
+++ b/src/crepe/api/Texture.cpp
@@ -9,14 +9,9 @@
 using namespace crepe;
 using namespace std;
 
-Texture::Texture(unique_ptr<Asset> res) {
+Texture::Texture(const Asset & src) {
 	dbg_trace();
-	this->load(std::move(res));
-}
-
-Texture::Texture(const char * src) {
-	dbg_trace();
-	this->load(make_unique<Asset>(src));
+	this->load(src);
 }
 
 Texture::~Texture() {
@@ -24,9 +19,9 @@ Texture::~Texture() {
 	this->texture.reset();
 }
 
-void Texture::load(unique_ptr<Asset> res) {
+void Texture::load(const Asset & res) {
 	SDLContext & ctx = SDLContext::get_instance();
-	this->texture = std::move(ctx.texture_from_path(res->get_path()));
+	this->texture = ctx.texture_from_path(res.get_path());
 }
 
 int Texture::get_width() const {
diff --git a/src/crepe/api/Texture.h b/src/crepe/api/Texture.h
index 6965223..b4f7d07 100644
--- a/src/crepe/api/Texture.h
+++ b/src/crepe/api/Texture.h
@@ -25,16 +25,10 @@ class Texture {
 
 public:
 	/**
-	 * \brief Constructs a Texture from a file path.
-	 * \param src Path to the image file to be loaded as a texture.
-	 */
-	Texture(const char * src);
-
-	/**
 	 * \brief Constructs a Texture from an Asset resource.
-	 * \param res Unique pointer to an Asset resource containing texture data.
+	 * \param src Asset with texture data to load.
 	 */
-	Texture(std::unique_ptr<Asset> res);
+	Texture(const Asset & src);
 
 	/**
 	 * \brief Destroys the Texture instance, freeing associated resources.
@@ -59,7 +53,7 @@ private:
 	 * \brief Loads the texture from an Asset resource.
 	 * \param res Unique pointer to an Asset resource to load the texture from.
 	 */
-	void load(std::unique_ptr<Asset> res);
+	void load(const Asset & res);
 
 private:
 	//! The texture of the class from the library