copy homemade ECS to crepe + correct code style

19 files changed, 487 insertions, 106 deletions

diff --git a/.clang-format b/.clang-format
index 5d233eb..d2918db 100644
--- a/.clang-format
+++ b/.clang-format
@@ -22,6 +22,7 @@ AlignTrailingComments:
 ReflowComments: false
 AlignEscapedNewlines: DontAlign
 BreakBeforeBinaryOperators: All
+BreakTemplateDeclarations: Yes
 ...
 
 # vim: ft=yaml
diff --git a/contributing.md b/contributing.md
index 2ff411a..933f1bf 100644
--- a/contributing.md
+++ b/contributing.md
@@ -17,6 +17,11 @@
 # Code style
 
 - ASCII only
+- Explanatory comments are placed above the line(s) they are explaining
+- Source files should only contain comments that plainly state what the code is
+  supposed to do
+- Explanatory comments in headers may be used to clarify implementation design
+  decisions
 - Formatting nitty-gritty is handled by clang-format/clang-tidy (run `make
   format` in the root folder of this repository to format all sources files)
 - When using libraries of which the header include order is important, make
diff --git a/mwe/ecs-homemade/inc/ComponentManager.h b/mwe/ecs-homemade/inc/ComponentManager.h
index 1a58b01..d368516 100644
--- a/mwe/ecs-homemade/inc/ComponentManager.h
+++ b/mwe/ecs-homemade/inc/ComponentManager.h
@@ -2,39 +2,44 @@
 
 #include "Components.h"
 #include <cstdint>
-#include <unordered_map>
-#include <vector>
-#include <typeindex>
 #include <memory>
+#include <typeindex>
+#include <unordered_map>
 #include <utility>
+#include <vector>
 
 class ComponentManager {
 public:
-	static ComponentManager& GetInstance();	//Singleton
+	static ComponentManager & GetInstance(); //Singleton
 
-	ComponentManager(const ComponentManager&) = delete;	//Singleton
-    ComponentManager(ComponentManager&&) = delete;	//Singleton
-    ComponentManager& operator=(const ComponentManager&) = delete;	//Singleton
-    ComponentManager& operator=(ComponentManager&&) = delete;	//Singleton
+	ComponentManager(const ComponentManager &) = delete; //Singleton
+	ComponentManager(ComponentManager &&) = delete; //Singleton
+	ComponentManager & operator=(const ComponentManager &) = delete; //Singleton
+	ComponentManager & operator=(ComponentManager &&) = delete; //Singleton
 
 	template <typename T, typename... Args>
-	void AddComponent(std::uint32_t id, Args&&... args);	//Add a component of a specific type
+	void AddComponent(std::uint32_t id,
+					  Args &&... args); //Add a component of a specific type
 	template <typename T>
-	void DeleteComponentsById(std::uint32_t id);	//Deletes all components of a specific type and id
+	void DeleteComponentsById(
+		std::uint32_t id); //Deletes all components of a specific type and id
 	template <typename T>
-	void DeleteComponents();	//Deletes all components of a specific type
-	void DeleteAllComponentsOfId(std::uint32_t id);	//Deletes all components of a specific id
-	void DeleteAllComponents();	//Deletes all components
+	void DeleteComponents(); //Deletes all components of a specific type
+	void DeleteAllComponentsOfId(
+		std::uint32_t id); //Deletes all components of a specific id
+	void DeleteAllComponents(); //Deletes all components
 
 	template <typename T>
-    std::vector<std::reference_wrapper<T>> GetComponentsByID(std::uint32_t id) const;	//Get a vector<> of all components at specific type and id
+	std::vector<std::reference_wrapper<T>> GetComponentsByID(std::uint32_t id)
+		const; //Get a vector<> of all components at specific type and id
 	template <typename T>
-	std::vector<std::reference_wrapper<T>> GetComponentsByType() const;	//Get a vector<> of all components of a specific type
+	std::vector<std::reference_wrapper<T>> GetComponentsByType()
+		const; //Get a vector<> of all components of a specific type
 
 private:
-    static ComponentManager mInstance;	//Singleton
+	static ComponentManager mInstance; //Singleton
 
-    ComponentManager();	//Singleton
+	ComponentManager(); //Singleton
 
 	/*
 	 * The std::unordered_map<std::type_index, std::vector<std::vector<std::unique_ptr<Component>>>> below might seem a bit strange, let me explain this structure:
@@ -42,7 +47,9 @@ private:
 	 * The first std::vector<> stores another vector<>. This first vector<> is to bind the entity's id to a component.
 	 * The second std::vector<> stores unique_ptrs. Each component can be gathered via an unique_ptr. This second vector<> allows multiple components of the same std::type_index for one entity (id).
 	 */
-	std::unordered_map<std::type_index, std::vector<std::vector<std::unique_ptr<Component>>>> mComponents;
+	std::unordered_map<std::type_index,
+					   std::vector<std::vector<std::unique_ptr<Component>>>>
+		mComponents;
 };
 
 #include "ComponentManager.hpp"
diff --git a/mwe/ecs-homemade/inc/ComponentManager.hpp b/mwe/ecs-homemade/inc/ComponentManager.hpp
index 720ee79..161ce71 100644
--- a/mwe/ecs-homemade/inc/ComponentManager.hpp
+++ b/mwe/ecs-homemade/inc/ComponentManager.hpp
@@ -1,88 +1,126 @@
 
 template <typename T, typename... Args>
-void ComponentManager::AddComponent(std::uint32_t id, Args&&... args) {
-    std::type_index type = typeid(T);	//Determine the type of T (this is used as the key of the unordered_map<>)
-
-    if (mComponents.find(type) == mComponents.end()) {	//Check if this component type is already in the unordered_map<>
-        mComponents[type] = std::vector<std::vector<std::unique_ptr<Component>>>();	//If not, create a new (empty) vector<> of vector<unique_ptr<Component>>
-    }
+void ComponentManager::AddComponent(std::uint32_t id, Args &&... args) {
+	std::type_index type = typeid(
+		T); //Determine the type of T (this is used as the key of the unordered_map<>)
+
+	if (mComponents.find(type)
+		== mComponents
+			   .end()) { //Check if this component type is already in the unordered_map<>
+		mComponents[type] = std::vector<std::vector<std::unique_ptr<
+			Component>>>(); //If not, create a new (empty) vector<> of vector<unique_ptr<Component>>
+	}
 
-    if (id >= mComponents[type].size()) {	//Resize the vector<> if the id is greater than the current size
-        mComponents[type].resize(id + 1);	//Initialize new slots to nullptr (resize does automatically init to nullptr)
-    }
+	if (id
+		>= mComponents[type]
+			   .size()) { //Resize the vector<> if the id is greater than the current size
+		mComponents[type].resize(
+			id
+			+ 1); //Initialize new slots to nullptr (resize does automatically init to nullptr)
+	}
 
-    mComponents[type][id].push_back(std::make_unique<T>(std::forward<Args>(args)...));	//Create a new component of type T using perfect forwarding and store its unique_ptr in the vector<>
+	mComponents[type][id].push_back(std::make_unique<T>(std::forward<Args>(
+		args)...)); //Create a new component of type T using perfect forwarding and store its unique_ptr in the vector<>
 }
 
 template <typename T>
 void ComponentManager::DeleteComponentsById(std::uint32_t id) {
-	std::type_index type = typeid(T);	//Determine the type of T (this is used as the key of the unordered_map<>)
-
-	if (mComponents.find(type) != mComponents.end()) {	//Find the type (in the unordered_map<>)
-		std::vector<std::vector<std::unique_ptr<Component>>>& componentArray = mComponents[type];	//Get the correct vector<>
-
-        if (id < componentArray.size()) {	//Make sure that the id (that we are looking for) is within the boundaries of the vector<>
-            componentArray[id].clear();	//Clear the whole vector<> of this specific type and id
-        }
+	std::type_index type = typeid(
+		T); //Determine the type of T (this is used as the key of the unordered_map<>)
+
+	if (mComponents.find(type)
+		!= mComponents.end()) { //Find the type (in the unordered_map<>)
+		std::vector<std::vector<std::unique_ptr<Component>>> & componentArray
+			= mComponents[type]; //Get the correct vector<>
+
+		if (id
+			< componentArray
+				  .size()) { //Make sure that the id (that we are looking for) is within the boundaries of the vector<>
+			componentArray[id]
+				.clear(); //Clear the whole vector<> of this specific type and id
+		}
 	}
 }
 
-template <typename T>
-void ComponentManager::DeleteComponents() {
-	std::type_index type = typeid(T);	//Determine the type of T (this is used as the key of the unordered_map<>)
+template <typename T> void ComponentManager::DeleteComponents() {
+	std::type_index type = typeid(
+		T); //Determine the type of T (this is used as the key of the unordered_map<>)
 
-	if (mComponents.find(type) != mComponents.end()) {	//Find the type (in the unordered_map<>)
-		mComponents[type].clear();	//Clear the whole vector<> of this specific type
+	if (mComponents.find(type)
+		!= mComponents.end()) { //Find the type (in the unordered_map<>)
+		mComponents[type]
+			.clear(); //Clear the whole vector<> of this specific type
 	}
 }
 
 template <typename T>
-std::vector<std::reference_wrapper<T>> ComponentManager::GetComponentsByID(std::uint32_t id) const {
-    std::type_index type = typeid(T);	//Determine the type of T (this is used as the key of the unordered_map<>)
-
-	std::vector<std::reference_wrapper<T>> componentVector;	//Create an empty vector<>
-
-    if (mComponents.find(type) != mComponents.end()) {	//Find the type (in the unordered_map<>)
-
-        const std::vector<std::vector<std::unique_ptr<Component>>>& componentArray = mComponents.at(type);	//Get the correct vector<>
-
-        if (id < componentArray.size()) {	//Make sure that the id (that we are looking for) is within the boundaries of the vector<>
-            for (const std::unique_ptr<Component>& componentPtr : componentArray[id]) {	//Loop trough the whole vector<>
-                T* castedComponent = static_cast<T*>(componentPtr.get());	//Cast the unique_ptr to a raw pointer
-
-                if (castedComponent) {	//Ensure that the cast was successful
-                    componentVector.push_back(*castedComponent); //Add the dereferenced raw pointer to the vector<>
-                }
-            }
-        }
-    }
+std::vector<std::reference_wrapper<T>>
+ComponentManager::GetComponentsByID(std::uint32_t id) const {
+	std::type_index type = typeid(
+		T); //Determine the type of T (this is used as the key of the unordered_map<>)
+
+	std::vector<std::reference_wrapper<T>>
+		componentVector; //Create an empty vector<>
+
+	if (mComponents.find(type)
+		!= mComponents.end()) { //Find the type (in the unordered_map<>)
+
+		const std::vector<std::vector<std::unique_ptr<Component>>> &
+			componentArray
+			= mComponents.at(type); //Get the correct vector<>
+
+		if (id
+			< componentArray
+				  .size()) { //Make sure that the id (that we are looking for) is within the boundaries of the vector<>
+			for (const std::unique_ptr<Component> & componentPtr :
+				 componentArray[id]) { //Loop trough the whole vector<>
+				T * castedComponent = static_cast<T *>(
+					componentPtr.get()); //Cast the unique_ptr to a raw pointer
+
+				if (castedComponent) { //Ensure that the cast was successful
+					componentVector.push_back(
+						*castedComponent); //Add the dereferenced raw pointer to the vector<>
+				}
+			}
+		}
+	}
 
-    return componentVector; //Return the vector<>
+	return componentVector; //Return the vector<>
 }
 
 template <typename T>
-std::vector<std::reference_wrapper<T>> ComponentManager::GetComponentsByType() const {
-    std::type_index type = typeid(T);	//Determine the type of T (this is used as the key of the unordered_map<>)
+std::vector<std::reference_wrapper<T>>
+ComponentManager::GetComponentsByType() const {
+	std::type_index type = typeid(
+		T); //Determine the type of T (this is used as the key of the unordered_map<>)
 
-    std::vector<std::reference_wrapper<T>> componentVector;	//Create an empty vector<>
+	std::vector<std::reference_wrapper<T>>
+		componentVector; //Create an empty vector<>
 	//std::uint32_t id = 0;	//Set the id to 0 (the id will also be stored in the returned vector<>)
 
-    if (mComponents.find(type) != mComponents.end()) {	//Find the type (in the unordered_map<>)
+	if (mComponents.find(type)
+		!= mComponents.end()) { //Find the type (in the unordered_map<>)
 
-        const std::vector<std::vector<std::unique_ptr<Component>>>& componentArray = mComponents.at(type);	//Get the correct vector<>
+		const std::vector<std::vector<std::unique_ptr<Component>>> &
+			componentArray
+			= mComponents.at(type); //Get the correct vector<>
 
-        for (const std::vector<std::unique_ptr<Component>>& component : componentArray) {	//Loop through the whole vector<>
-            for (const std::unique_ptr<Component>& componentPtr : component) {	//Loop trough the whole vector<>
-                T* castedComponent = static_cast<T*>(componentPtr.get());	//Cast the unique_ptr to a raw pointer
+		for (const std::vector<std::unique_ptr<Component>> & component :
+			 componentArray) { //Loop through the whole vector<>
+			for (const std::unique_ptr<Component> & componentPtr :
+				 component) { //Loop trough the whole vector<>
+				T * castedComponent = static_cast<T *>(
+					componentPtr.get()); //Cast the unique_ptr to a raw pointer
 
-                if (castedComponent) {	//Ensure that the cast was successful
-                    componentVector.emplace_back(std::ref(*castedComponent));	//Pair the dereferenced raw pointer and the id and add it to the vector<>
-                }
-            }
+				if (castedComponent) { //Ensure that the cast was successful
+					componentVector.emplace_back(std::ref(
+						*castedComponent)); //Pair the dereferenced raw pointer and the id and add it to the vector<>
+				}
+			}
 
 			//++id;	//Increase the id (the id will also be stored in the returned vector<>)
-        }
-    }
+		}
+	}
 
-    return componentVector;	//Return the vector<>
+	return componentVector; //Return the vector<>
 }
diff --git a/mwe/ecs-homemade/inc/GameObjectMax.h b/mwe/ecs-homemade/inc/GameObjectMax.h
index f0bcec9..c88a834 100644
--- a/mwe/ecs-homemade/inc/GameObjectMax.h
+++ b/mwe/ecs-homemade/inc/GameObjectMax.h
@@ -7,8 +7,7 @@ class GameObject {
 public:
 	GameObject(std::uint32_t id, std::string name, std::string tag, int layer);
 
-	template <typename T, typename... Args>
-	void AddComponent(Args&&... args);
+	template <typename T, typename... Args> void AddComponent(Args &&... args);
 
 	std::uint32_t mId;
 	std::string mName;
diff --git a/mwe/ecs-homemade/inc/GameObjectMax.hpp b/mwe/ecs-homemade/inc/GameObjectMax.hpp
index 1e952ba..91d51ea 100644
--- a/mwe/ecs-homemade/inc/GameObjectMax.hpp
+++ b/mwe/ecs-homemade/inc/GameObjectMax.hpp
@@ -1,6 +1,7 @@
 #include "ComponentManager.h"
 
 template <typename T, typename... Args>
-void GameObject::AddComponent(Args&&... args) {
-	ComponentManager::GetInstance().AddComponent<T>(mId, std::forward<Args>(args)...);
+void GameObject::AddComponent(Args &&... args) {
+	ComponentManager::GetInstance().AddComponent<T>(
+		mId, std::forward<Args>(args)...);
 }
diff --git a/mwe/ecs-homemade/src/ComponentManager.cpp b/mwe/ecs-homemade/src/ComponentManager.cpp
index 16cc2b6..536c152 100644
--- a/mwe/ecs-homemade/src/ComponentManager.cpp
+++ b/mwe/ecs-homemade/src/ComponentManager.cpp
@@ -2,20 +2,22 @@
 
 ComponentManager ComponentManager::mInstance;
 
-ComponentManager& ComponentManager::GetInstance() {
-	return mInstance;
-}
+ComponentManager & ComponentManager::GetInstance() { return mInstance; }
 
 ComponentManager::ComponentManager() {}
 
 void ComponentManager::DeleteAllComponentsOfId(std::uint32_t id) {
-    for(auto& [type, componentArray] : mComponents) {	//Loop through all the types (in the unordered_map<>)
-        if (id < componentArray.size()) {	//Make sure that the id (that we are looking for) is within the boundaries of the vector<>
-            componentArray[id].clear();	//Clear the components at this specific id
-        }
-    }
+	for (auto & [type, componentArray] :
+		 mComponents) { //Loop through all the types (in the unordered_map<>)
+		if (id
+			< componentArray
+				  .size()) { //Make sure that the id (that we are looking for) is within the boundaries of the vector<>
+			componentArray[id]
+				.clear(); //Clear the components at this specific id
+		}
+	}
 }
 
 void ComponentManager::DeleteAllComponents() {
-	mComponents.clear();	//Clear the whole unordered_map<>
+	mComponents.clear(); //Clear the whole unordered_map<>
 }
diff --git a/mwe/ecs-homemade/src/Components.cpp b/mwe/ecs-homemade/src/Components.cpp
index 69b5eaa..c8347b3 100644
--- a/mwe/ecs-homemade/src/Components.cpp
+++ b/mwe/ecs-homemade/src/Components.cpp
@@ -5,6 +5,7 @@ Component::Component() : mActive(true) {}
 
 Sprite::Sprite(std::string path) : mPath(path) {}
 
-Rigidbody::Rigidbody(int mass, int gravityScale, int bodyType) : mMass(mass), mGravityScale(gravityScale), mBodyType(bodyType) {}
+Rigidbody::Rigidbody(int mass, int gravityScale, int bodyType)
+	: mMass(mass), mGravityScale(gravityScale), mBodyType(bodyType) {}
 
 Colider::Colider(int size) : mSize(size) {}
diff --git a/mwe/ecs-homemade/src/GameObjectMax.cpp b/mwe/ecs-homemade/src/GameObjectMax.cpp
index 62c41de..b0c5af7 100644
--- a/mwe/ecs-homemade/src/GameObjectMax.cpp
+++ b/mwe/ecs-homemade/src/GameObjectMax.cpp
@@ -2,4 +2,6 @@
 
 #include "ComponentManager.h"
 
-GameObject::GameObject(std::uint32_t id, std::string name, std::string tag, int layer) : mId(id), mName(name), mTag(tag), mActive(true), mLayer(layer) {}
+GameObject::GameObject(std::uint32_t id, std::string name, std::string tag,
+					   int layer)
+	: mId(id), mName(name), mTag(tag), mActive(true), mLayer(layer) {}
diff --git a/mwe/ecs-homemade/src/main.cpp b/mwe/ecs-homemade/src/main.cpp
index 41f7d6d..330e154 100644
--- a/mwe/ecs-homemade/src/main.cpp
+++ b/mwe/ecs-homemade/src/main.cpp
@@ -1,54 +1,59 @@
+#include <chrono>
+#include <cstdint>
 #include <iostream>
 #include <vector>
-#include <cstdint>
-#include <chrono>
 
 #include "ComponentManager.h"
-#include "GameObjectMax.h"
 #include "Components.h"
+#include "GameObjectMax.h"
 
 int main() {
 	auto startAdding = std::chrono::high_resolution_clock::now();
 
-	GameObject* gameObject[100000];
+	GameObject * gameObject[100000];
 
-	for(int i = 0; i < 100000; ++i) {
+	for (int i = 0; i < 100000; ++i) {
 		gameObject[i] = new GameObject(i, "Name", "Tag", 0);
 
 		gameObject[i]->AddComponent<Sprite>("C:/Test");
 		gameObject[i]->AddComponent<Rigidbody>(0, 0, i);
 		gameObject[i]->AddComponent<Colider>(i);
 	}
-	
+
 	auto stopAdding = std::chrono::high_resolution_clock::now();
 
 	//This is what systems would do:
 
-	std::vector<std::reference_wrapper<Sprite>> sprites = ComponentManager::GetInstance().GetComponentsByType<Sprite>();
-	for(Sprite& sprite : sprites) {
+	std::vector<std::reference_wrapper<Sprite>> sprites
+		= ComponentManager::GetInstance().GetComponentsByType<Sprite>();
+	for (Sprite & sprite : sprites) {
 		//std::cout << sprite.get().mPath << std::endl;
 	}
 	//std::cout << std::endl;
 
-	std::vector<std::reference_wrapper<Rigidbody>> rigidBodies = ComponentManager::GetInstance().GetComponentsByType<Rigidbody>();
-	for(Rigidbody& rigidbody : rigidBodies) {
+	std::vector<std::reference_wrapper<Rigidbody>> rigidBodies
+		= ComponentManager::GetInstance().GetComponentsByType<Rigidbody>();
+	for (Rigidbody & rigidbody : rigidBodies) {
 		//std::cout << rigidbody.get().mMass << " " << rigidbody.get().mGravityScale << " " << rigidbody.get().mBodyType << std::endl;
 	}
 	//std::cout << std::endl;
 
-	std::vector<std::reference_wrapper<Colider>> coliders = ComponentManager::GetInstance().GetComponentsByType<Colider>();
-	for(Colider& colider : coliders) {
+	std::vector<std::reference_wrapper<Colider>> coliders
+		= ComponentManager::GetInstance().GetComponentsByType<Colider>();
+	for (Colider & colider : coliders) {
 		//std::cout << colider.get().mSize << std::endl;
 	}
 
 	auto stopLooping = std::chrono::high_resolution_clock::now();
 
 	for (int i = 0; i < 100000; ++i) {
-    	delete gameObject[i];
+		delete gameObject[i];
 	}
 
-	auto Addtime = std::chrono::duration_cast<std::chrono::microseconds>(stopAdding - startAdding);
-	auto LoopTime = std::chrono::duration_cast<std::chrono::microseconds>(stopLooping - stopAdding);
+	auto Addtime = std::chrono::duration_cast<std::chrono::microseconds>(
+		stopAdding - startAdding);
+	auto LoopTime = std::chrono::duration_cast<std::chrono::microseconds>(
+		stopLooping - stopAdding);
 	std::cout << "AddTime: " << Addtime.count() << " us" << std::endl;
 	std::cout << "LoopTime: " << LoopTime.count() << " us" << std::endl;
 }
diff --git a/src/crepe/CMakeLists.txt b/src/crepe/CMakeLists.txt
index 208ba1f..5840208 100644
--- a/src/crepe/CMakeLists.txt
+++ b/src/crepe/CMakeLists.txt
@@ -2,12 +2,20 @@ target_sources(crepe PUBLIC
 	Asset.cpp
 	Sound.cpp
 	SoundContext.cpp
+	ComponentManager.cpp
+	Components.cpp
+	GameObject.cpp
 )
 
 target_sources(crepe PUBLIC FILE_SET HEADERS FILES
 	Asset.h
 	Sound.h
 	SoundContext.h
+	ComponentManager.h
+	ComponentManager.hpp
+	Components.h
+	GameObject.h
+	GameObject.hpp
 )
 
 add_subdirectory(api)
diff --git a/src/crepe/ComponentManager.cpp b/src/crepe/ComponentManager.cpp
new file mode 100644
index 0000000..b7a1bea
--- /dev/null
+++ b/src/crepe/ComponentManager.cpp
@@ -0,0 +1,25 @@
+#include "ComponentManager.h"
+
+using namespace crepe;
+
+ComponentManager & ComponentManager::get_instance() {
+	static ComponentManager instance;
+	return instance;
+}
+
+void ComponentManager::DeleteAllComponentsOfId(std::uint32_t id) {
+	// Loop through all the types (in the unordered_map<>)
+	for (auto & [type, componentArray] : components) {
+		// Make sure that the id (that we are looking for) is within the boundaries of the vector<>
+		if (id < componentArray.size()) {
+			// Clear the components at this specific id
+			componentArray[id].clear();
+		}
+	}
+}
+
+void ComponentManager::DeleteAllComponents() {
+	// Clear the whole unordered_map<>
+	components.clear();
+}
+
diff --git a/src/crepe/ComponentManager.h b/src/crepe/ComponentManager.h
new file mode 100644
index 0000000..003cd0b
--- /dev/null
+++ b/src/crepe/ComponentManager.h
@@ -0,0 +1,55 @@
+#pragma once
+
+#include <cstdint>
+#include <memory>
+#include <typeindex>
+#include <unordered_map>
+#include <utility>
+#include <vector>
+
+#include "Components.h"
+
+namespace crepe {
+
+class ComponentManager {
+public:
+	// Singleton
+	static ComponentManager & get_instance();
+	ComponentManager(const ComponentManager &) = delete;
+	ComponentManager(ComponentManager &&) = delete;
+	ComponentManager & operator=(const ComponentManager &) = delete;
+	ComponentManager & operator=(ComponentManager &&) = delete;
+
+public:
+	//! Add a component of a specific type
+	template <typename T, typename... Args> void AddComponent(std::uint32_t id, Args &&... args);
+	//! Deletes all components of a specific type and id
+	template <typename T> void DeleteComponentsById(std::uint32_t id);
+	//! Deletes all components of a specific type
+	template <typename T> void DeleteComponents();
+	//! Deletes all components of a specific id
+	void DeleteAllComponentsOfId(std::uint32_t id);
+	//! Deletes all components
+	void DeleteAllComponents();
+
+	//! Get a vector<> of all components at specific type and id
+	template <typename T> std::vector<std::reference_wrapper<T>> GetComponentsByID(std::uint32_t id) const;
+	//! Get a vector<> of all components of a specific type
+	template <typename T> std::vector<std::reference_wrapper<T>> GetComponentsByType() const;
+
+private:
+	ComponentManager() = default;
+
+	/*
+	 * The std::unordered_map<std::type_index, std::vector<std::vector<std::unique_ptr<Component>>>> below might seem a bit strange, let me explain this structure:
+	 * The std::unordered_map<> has a key and value. The key is a std::type_index and the value is a std::vector. So, a new std::vector will be created for each new std::type_index.
+	 * The first std::vector<> stores another vector<>. This first vector<> is to bind the entity's id to a component.
+	 * The second std::vector<> stores unique_ptrs. Each component can be gathered via an unique_ptr. This second vector<> allows multiple components of the same std::type_index for one entity (id).
+	 */
+	std::unordered_map<std::type_index, std::vector<std::vector<std::unique_ptr<Component>>>> components;
+};
+
+}
+
+// #include "ComponentManager.hpp"
+
diff --git a/src/crepe/ComponentManager.hpp b/src/crepe/ComponentManager.hpp
new file mode 100644
index 0000000..602490e
--- /dev/null
+++ b/src/crepe/ComponentManager.hpp
@@ -0,0 +1,134 @@
+#pragma once
+
+#include "ComponentManager.h"
+
+namespace crepe {
+
+template <typename T, typename... Args>
+void ComponentManager::AddComponent(std::uint32_t id, Args &&... args) {
+	// Determine the type of T (this is used as the key of the unordered_map<>)
+	std::type_index type = typeid(T);
+
+	// Check if this component type is already in the unordered_map<>
+	if (components.find(type) == components.end()) {
+		//If not, create a new (empty) vector<> of vector<unique_ptr<Component>>
+		components[type] = std::vector<std::vector<std::unique_ptr<Component>>>();
+	}
+
+	// Resize the vector<> if the id is greater than the current size
+	if (id >= components[type].size()) {
+		// Initialize new slots to nullptr (resize does automatically init to nullptr)
+		components[type].resize(id + 1);
+	}
+
+	// Create a new component of type T using perfect forwarding and store its
+	// unique_ptr in the vector<>
+	components[type][id].push_back(std::make_unique<T>(std::forward<Args>(args)...));
+}
+
+template <typename T>
+void ComponentManager::DeleteComponentsById(std::uint32_t id) {
+	// Determine the type of T (this is used as the key of the unordered_map<>)
+	std::type_index type = typeid(T);
+
+	// Find the type (in the unordered_map<>)
+	if (components.find(type) != components.end()) {
+		// Get the correct vector<>
+		std::vector<std::vector<std::unique_ptr<Component>>> & componentArray = components[type];
+
+		// Make sure that the id (that we are looking for) is within the boundaries of the vector<>
+		if (id < componentArray.size()) {
+			// Clear the whole vector<> of this specific type and id
+			componentArray[id].clear();
+		}
+	}
+}
+
+template <typename T>
+void ComponentManager::DeleteComponents() {
+	// Determine the type of T (this is used as the key of the unordered_map<>)
+	std::type_index type = typeid(T);
+
+	// Find the type (in the unordered_map<>)
+	if (components.find(type) != components.end()) {
+		// Clear the whole vector<> of this specific type
+		components[type].clear();
+	}
+}
+
+template <typename T>
+std::vector<std::reference_wrapper<T>>
+ComponentManager::GetComponentsByID(std::uint32_t id) const {
+	// Determine the type of T (this is used as the key of the unordered_map<>)
+	std::type_index type = typeid(T);
+
+	// Create an empty vector<>
+	std::vector<std::reference_wrapper<T>> componentVector;
+
+	// Find the type (in the unordered_map<>)
+	if (components.find(type) != components.end()) {
+		// Get the correct vector<>
+		const std::vector<std::vector<std::unique_ptr<Component>>> & componentArray = components.at(type);
+
+		// Make sure that the id (that we are looking for) is within the boundaries of the vector<>
+		if (id < componentArray .size()) {
+			// Loop trough the whole vector<>
+			for (const std::unique_ptr<Component> & componentPtr : componentArray[id]) {
+				// Cast the unique_ptr to a raw pointer
+				T * castedComponent = static_cast<T *>(componentPtr.get());
+
+				// Ensure that the cast was successful
+				if (castedComponent) {
+					// Add the dereferenced raw pointer to the vector<>
+					componentVector.push_back(*castedComponent);
+				}
+			}
+		}
+	}
+
+	// Return the vector<>
+	return componentVector;
+}
+
+template <typename T>
+std::vector<std::reference_wrapper<T>>
+ComponentManager::GetComponentsByType() const {
+	// Determine the type of T (this is used as the key of the unordered_map<>)
+	std::type_index type = typeid(T);
+
+	// Create an empty vector<>
+	std::vector<std::reference_wrapper<T>> componentVector;
+	// Set the id to 0 (the id will also be stored in the returned vector<>)
+	// std::uint32_t id = 0;
+
+	// Find the type (in the unordered_map<>)
+	if (components.find(type) != components.end()) {
+
+		// Get the correct vector<>
+		const std::vector<std::vector<std::unique_ptr<Component>>> & componentArray = components.at(type);
+
+		// Loop through the whole vector<>
+		for (const std::vector<std::unique_ptr<Component>> & component : componentArray) {
+			// Loop trough the whole vector<>
+			for (const std::unique_ptr<Component> & componentPtr : component) {
+				// Cast the unique_ptr to a raw pointer
+				T * castedComponent = static_cast<T *>(componentPtr.get());
+
+				// Ensure that the cast was successful
+				if (castedComponent) {
+					// Pair the dereferenced raw pointer and the id and add it to the vector<>
+					componentVector.emplace_back(std::ref(*castedComponent));
+				}
+			}
+
+			// Increase the id (the id will also be stored in the returned vector<>)
+			//++id;
+		}
+	}
+
+	// Return the vector<>
+	return componentVector;
+}
+
+}
+
diff --git a/src/crepe/Components.cpp b/src/crepe/Components.cpp
new file mode 100644
index 0000000..9760daa
--- /dev/null
+++ b/src/crepe/Components.cpp
@@ -0,0 +1,13 @@
+#include "Components.h"
+#include <iostream>
+
+using namespace crepe;
+
+Component::Component() : mActive(true) {}
+
+Sprite::Sprite(std::string path) : mPath(path) {}
+
+Rigidbody::Rigidbody(int mass, int gravityScale, int bodyType)
+	: mMass(mass), mGravityScale(gravityScale), mBodyType(bodyType) {}
+
+Colider::Colider(int size) : mSize(size) {}
diff --git a/src/crepe/Components.h b/src/crepe/Components.h
new file mode 100644
index 0000000..7cb6fbb
--- /dev/null
+++ b/src/crepe/Components.h
@@ -0,0 +1,39 @@
+#pragma once
+
+#include <string>
+
+namespace crepe {
+
+class Component {
+public:
+	Component();
+
+	bool mActive;
+};
+
+// TODO: these should be in separate files
+
+class Sprite : public Component {
+public:
+	Sprite(std::string path);
+
+	std::string mPath;
+};
+
+class Rigidbody : public Component {
+public:
+	Rigidbody(int mass, int gravityScale, int bodyType);
+
+	int mMass;
+	int mGravityScale;
+	int mBodyType;
+};
+
+class Colider : public Component {
+public:
+	Colider(int size);
+
+	int mSize;
+};
+
+}
diff --git a/src/crepe/GameObject.cpp b/src/crepe/GameObject.cpp
new file mode 100644
index 0000000..5ac9d7a
--- /dev/null
+++ b/src/crepe/GameObject.cpp
@@ -0,0 +1,9 @@
+#include "GameObject.h"
+
+#include "ComponentManager.h"
+
+using namespace crepe;
+
+GameObject::GameObject(std::uint32_t id, std::string name, std::string tag,
+					   int layer)
+	: mId(id), mName(name), mTag(tag), mActive(true), mLayer(layer) {}
diff --git a/src/crepe/GameObject.h b/src/crepe/GameObject.h
new file mode 100644
index 0000000..71ef60d
--- /dev/null
+++ b/src/crepe/GameObject.h
@@ -0,0 +1,22 @@
+#pragma once
+
+#include <cstdint>
+#include <string>
+
+namespace crepe {
+
+class GameObject {
+public:
+	GameObject(std::uint32_t id, std::string name, std::string tag, int layer);
+
+	template <typename T, typename... Args> void AddComponent(Args &&... args);
+
+	std::uint32_t mId;
+	std::string mName;
+	std::string mTag;
+	bool mActive;
+	int mLayer;
+};
+
+}
+
diff --git a/src/crepe/GameObject.hpp b/src/crepe/GameObject.hpp
new file mode 100644
index 0000000..5a672cf
--- /dev/null
+++ b/src/crepe/GameObject.hpp
@@ -0,0 +1,15 @@
+#pragma once
+
+#include "GameObject.h"
+
+#include "ComponentManager.h"
+
+namespace crepe {
+
+template <typename T, typename... Args>
+void GameObject::AddComponent(Args &&... args) {
+	ComponentManager::get_instance().AddComponent<T>(mId, std::forward<Args>(args)...);
+}
+
+}
+