Replaced ComponentManager reference by OptionalRef for late binding

6 files changed, 26 insertions, 23 deletions

diff --git a/src/crepe/api/CMakeLists.txt b/src/crepe/api/CMakeLists.txt
index d6b6801..4025a63 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
 	Vector2.cpp
 	Camera.cpp
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..22aadab 100644
--- a/src/crepe/api/Scene.h
+++ b/src/crepe/api/Scene.h
@@ -1,5 +1,6 @@
 #pragma once
 
+#include "util/OptionalRef.h"
 #include <string>
 
 namespace crepe {
@@ -15,11 +16,8 @@ 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 +34,20 @@ 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..1edaa7d 100644
--- a/src/crepe/api/SceneManager.hpp
+++ b/src/crepe/api/SceneManager.hpp
@@ -4,12 +4,15 @@
 
 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);
+	Scene * scene = new T(std::forward<args>(args)...);
+
+	scene->component_manager = this->component_manager;
+
 	this->scenes.emplace_back(unique_ptr<Scene>(scene));
 
 	// The first scene added, is the one that will be loaded at the beginning
diff --git a/src/test/SceneManagerTest.cpp b/src/test/SceneManagerTest.cpp
index 1efcfb2..1706de0 100644
--- a/src/test/SceneManagerTest.cpp
+++ b/src/test/SceneManagerTest.cpp
@@ -12,10 +12,8 @@ using namespace crepe;
 
 class ConcreteScene1 : public Scene {
 public:
-	using Scene::Scene;
-
 	void load_scene() {
-		auto & mgr = this->component_manager;
+		ComponentManager & mgr = this->component_manager;
 		GameObject object1 = mgr.new_object("scene_1", "tag_scene_1", Vector2{0, 0}, 0, 1);
 		GameObject object2 = mgr.new_object("scene_1", "tag_scene_1", Vector2{1, 0}, 0, 1);
 		GameObject object3 = mgr.new_object("scene_1", "tag_scene_1", Vector2{2, 0}, 0, 1);
@@ -26,10 +24,8 @@ public:
 
 class ConcreteScene2 : public Scene {
 public:
-	using Scene::Scene;
-
 	void load_scene() {
-		auto & mgr = this->component_manager;
+		ComponentManager & mgr = this->component_manager;
 		GameObject object1 = mgr.new_object("scene_2", "tag_scene_2", Vector2{0, 0}, 0, 1);
 		GameObject object2 = mgr.new_object("scene_2", "tag_scene_2", Vector2{0, 1}, 0, 1);
 		GameObject object3 = mgr.new_object("scene_2", "tag_scene_2", Vector2{0, 2}, 0, 1);