8 files changed, 184 insertions, 0 deletions

diff --git a/src/crepe/api/CMakeLists.txt b/src/crepe/api/CMakeLists.txt
index 0bb1263..7fd8ffd 100644
--- a/src/crepe/api/CMakeLists.txt
+++ b/src/crepe/api/CMakeLists.txt
@@ -11,6 +11,8 @@ target_sources(crepe PUBLIC
 	Texture.cpp
 	AssetManager.cpp
 	Sprite.cpp
+	Scene.cpp
+	SceneManager.cpp
 )
 
 target_sources(crepe PUBLIC FILE_SET HEADERS FILES
@@ -28,4 +30,7 @@ target_sources(crepe PUBLIC FILE_SET HEADERS FILES
 	Texture.h 
 	AssetManager.h 
 	AssetManager.hpp
+	Scene.h
+	SceneManager.h
+	SceneManager.hpp
 )
diff --git a/src/crepe/api/Scene.cpp b/src/crepe/api/Scene.cpp
new file mode 100644
index 0000000..092dc62
--- /dev/null
+++ b/src/crepe/api/Scene.cpp
@@ -0,0 +1,5 @@
+#include "Scene.h"
+
+using namespace crepe;
+
+Scene::Scene(std::string name) : name(name) {}
diff --git a/src/crepe/api/Scene.h b/src/crepe/api/Scene.h
new file mode 100644
index 0000000..8bb487a
--- /dev/null
+++ b/src/crepe/api/Scene.h
@@ -0,0 +1,17 @@
+#pragma once
+
+#include <string>
+
+namespace crepe {
+
+class Scene {
+public:
+	Scene(std::string name);
+	virtual ~Scene() = default;
+	virtual void load_scene() = 0;
+
+public:
+	std::string name;
+};
+
+} // namespace crepe
diff --git a/src/crepe/api/SceneManager.cpp b/src/crepe/api/SceneManager.cpp
new file mode 100644
index 0000000..c8061c9
--- /dev/null
+++ b/src/crepe/api/SceneManager.cpp
@@ -0,0 +1,34 @@
+#include "../ComponentManager.h"
+
+#include "SceneManager.h"
+
+using namespace crepe;
+
+SceneManager::SceneManager() {}
+
+SceneManager & SceneManager::get_instance() {
+	static SceneManager instance;
+	return instance;
+}
+
+// Push the next scene onto the queue
+void SceneManager::load_scene(std::string name) { next_scene.push(name); }
+
+// Load a new scene from the queue (if there is one)
+void SceneManager::empty_queue() {
+	while (!next_scene.empty()) {
+		string name = next_scene.front();
+		next_scene.pop();
+
+		for (auto & scene : scenes) {
+			if (scene->name == name) {
+				// Delete all components of the current scene
+				ComponentManager & mgr = ComponentManager::get_instance();
+				mgr.delete_all_components();
+				// Load the new scene
+				scene->load_scene();
+				break;
+			}
+		}
+	}
+}
diff --git a/src/crepe/api/SceneManager.h b/src/crepe/api/SceneManager.h
new file mode 100644
index 0000000..87db8d7
--- /dev/null
+++ b/src/crepe/api/SceneManager.h
@@ -0,0 +1,36 @@
+#pragma once
+
+#include <memory>
+#include <queue>
+#include <vector>
+
+#include "Scene.h"
+
+namespace crepe {
+
+class SceneManager {
+public:
+	// Singleton
+	static SceneManager & get_instance();
+	SceneManager(const SceneManager &) = delete;
+	SceneManager(SceneManager &&) = delete;
+	SceneManager & operator=(const SceneManager &) = delete;
+	SceneManager & operator=(SceneManager &&) = delete;
+
+public:
+	template <typename T>
+	void add_scene(std::string name);
+	void load_scene(std::string name);
+	void empty_queue();
+
+private:
+	SceneManager();
+
+private:
+	std::vector<std::unique_ptr<Scene>> scenes;
+	std::queue<std::string> next_scene;
+};
+
+} // namespace crepe
+
+#include "SceneManager.hpp"
diff --git a/src/crepe/api/SceneManager.hpp b/src/crepe/api/SceneManager.hpp
new file mode 100644
index 0000000..7789823
--- /dev/null
+++ b/src/crepe/api/SceneManager.hpp
@@ -0,0 +1,11 @@
+#include "SceneManager.h"
+
+using namespace crepe;
+using namespace std;
+
+// Add a new concrete scene to the scene manager
+template <typename T>
+void SceneManager::add_scene(string name) {
+	static_assert(is_base_of<Scene, T>::value, "T must be derived from Scene");
+	scenes.emplace_back(make_unique<T>(name));
+}
diff --git a/src/example/CMakeLists.txt b/src/example/CMakeLists.txt
index 81df8d1..023d0ad 100644
--- a/src/example/CMakeLists.txt
+++ b/src/example/CMakeLists.txt
@@ -25,3 +25,4 @@ add_example(asset_manager)
 add_example(particle)
 add_example(physics)
 add_example(ecs)
+add_example(scene_manager)
diff --git a/src/example/scene_manager.cpp b/src/example/scene_manager.cpp
new file mode 100644
index 0000000..f1fe86a
--- /dev/null
+++ b/src/example/scene_manager.cpp
@@ -0,0 +1,75 @@
+#include <iostream>
+
+#include "../crepe/ComponentManager.h"
+#include "../crepe/Metadata.h"
+#include "../crepe/api/GameObject.h"
+#include "../crepe/api/Scene.h"
+#include "../crepe/api/SceneManager.h"
+
+using namespace crepe;
+using namespace std;
+
+class concreteScene1 : public Scene {
+public:
+	concreteScene1(string name) : Scene(name) {}
+
+	void load_scene() {
+		GameObject object1(0, "scene_1", "tag_scene_1", Point{0, 0}, 0, 1);
+		GameObject object2(1, "scene_1", "tag_scene_1", Point{1, 0}, 0, 1);
+		GameObject object3(2, "scene_1", "tag_scene_1", Point{2, 0}, 0, 1);
+	}
+};
+
+class concreteScene2 : public Scene {
+public:
+	concreteScene2(string name) : Scene(name) {}
+
+	void load_scene() {
+		GameObject object1(0, "scene_2", "tag_scene_2", Point{0, 0}, 0, 1);
+		GameObject object2(1, "scene_2", "tag_scene_2", Point{0, 1}, 0, 1);
+		GameObject object3(2, "scene_2", "tag_scene_2", Point{0, 2}, 0, 1);
+		GameObject object4(3, "scene_2", "tag_scene_2", Point{0, 3}, 0, 1);
+	}
+};
+
+int main() {
+	SceneManager & scene_mgr = SceneManager::get_instance();
+
+	// Add the scenes to the scene manager
+	scene_mgr.add_scene<concreteScene1>("scene1");
+	scene_mgr.add_scene<concreteScene2>("scene2");
+
+	// Load scene1 to the queue
+	scene_mgr.load_scene("scene1");
+	// Empty the queue (now scene1 is loaded)
+	scene_mgr.empty_queue();
+
+	// Get the Metadata components of each GameObject of Scene1
+	ComponentManager & component_mgr = ComponentManager::get_instance();
+	vector<reference_wrapper<Metadata>> metadata
+		= component_mgr.get_components_by_type<Metadata>();
+
+	cout << "Metadata components of Scene1:" << endl;
+	// Print the Metadata
+	for (auto & m : metadata) {
+		cout << "Id: " << m.get().game_object_id << " Name: " << m.get().name
+			 << " Tag: " << m.get().tag << endl;
+	}
+
+	// Load scene2 to the queue
+	scene_mgr.load_scene("scene2");
+	// Empty the queue (now scene2 is loaded)
+	scene_mgr.empty_queue();
+
+	// Get the Metadata components of each GameObject of Scene2
+	metadata = component_mgr.get_components_by_type<Metadata>();
+
+	cout << "Metadata components of Scene2:" << endl;
+	// Print the Metadata
+	for (auto & m : metadata) {
+		cout << "Id: " << m.get().game_object_id << " Name: " << m.get().name
+			 << " Tag: " << m.get().tag << endl;
+	}
+
+	return 0;
+}