Merge branch 'master' into niels/rendering

45 files changed, 760 insertions, 115 deletions

diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index a9193fd..09c60bd 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -3,36 +3,37 @@ cmake_minimum_required(VERSION 3.28)
 set(CMAKE_C_STANDARD 11)
 set(CMAKE_CXX_STANDARD 20)
 set(CMAKE_EXPORT_COMPILE_COMMANDS 1)
-
-# enable debug features
 set(CMAKE_BUILD_TYPE Debug)
-add_compile_definitions(DEBUG)
-
-add_subdirectory(../lib/soloud soloud)
-add_subdirectory(../lib/sdl_image/src SDL2_image)
 
 project(crepe C CXX)
 
+find_package(SDL2 REQUIRED)
+find_package(SoLoud REQUIRED)
+find_package(GTest REQUIRED)
+
 add_library(crepe SHARED)
+add_executable(test_main EXCLUDE_FROM_ALL)
 
 target_include_directories(crepe
 	PUBLIC SYSTEM INTERFACE .
 )
 
-# TODO: libraries should be linked as PRIVATE
 target_link_libraries(crepe
-	PUBLIC soloud
-	PUBLIC SDL2
-	PUBLIC SDL2_image
+	PRIVATE soloud
+	PRIVATE SDL2
 )
 
 add_subdirectory(crepe)
+add_subdirectory(test)
+add_subdirectory(example)
 
 install(
 	TARGETS crepe
 	FILE_SET HEADERS DESTINATION include/crepe
 )
 
-add_executable(dummy_rm dummy_rendering.cpp)
-#add_executable(dummy_rm dummy_audio.cpp)
-target_link_libraries(dummy_rm PUBLIC crepe)
+target_link_libraries(test_main
+	PRIVATE gtest_main
+	PUBLIC crepe
+)
+
diff --git a/src/crepe/Asset.cpp b/src/crepe/Asset.cpp
new file mode 100644
index 0000000..15ddc27
--- /dev/null
+++ b/src/crepe/Asset.cpp
@@ -0,0 +1,14 @@
+#include <filesystem>
+
+#include "Asset.h"
+
+using namespace crepe;
+
+Asset::Asset(const std::string & src) {
+	this->src = std::filesystem::canonical(src);
+	this->file = std::ifstream(this->src, std::ios::in | std::ios::binary);
+}
+
+const std::istream & Asset::read() { return this->file; }
+
+const char * Asset::canonical() { return this->src.c_str(); }
diff --git a/src/crepe/Asset.h b/src/crepe/Asset.h
new file mode 100644
index 0000000..0cb5834
--- /dev/null
+++ b/src/crepe/Asset.h
@@ -0,0 +1,33 @@
+#pragma once
+
+#include <fstream>
+#include <iostream>
+#include <string>
+
+namespace crepe {
+
+/**
+ * \brief Asset location helper
+ *
+ * This class is used to locate and canonicalize paths to game asset files, and
+ * should *always* be used when retrieving files from disk.
+ */
+class Asset {
+public:
+	/**
+	 * \param src  Unique identifier to asset
+	 */
+	Asset(const std::string & src);
+
+public:
+	//! Get an input stream to the contents of this resource
+	const std::istream & read();
+	//! Get the canonical path to this resource
+	const char * canonical();
+
+private:
+	std::string src;
+	std::ifstream file;
+};
+
+} // namespace crepe
diff --git a/src/crepe/CMakeLists.txt b/src/crepe/CMakeLists.txt
index 05f14d1..addb9dd 100644
--- a/src/crepe/CMakeLists.txt
+++ b/src/crepe/CMakeLists.txt
@@ -1,7 +1,31 @@
 target_sources(crepe PUBLIC
+	Asset.cpp
+	Sound.cpp
+	SoundContext.cpp
+	ComponentManager.cpp
+	Component.cpp
+	GameObject.cpp
+	Collider.cpp
+	Rigidbody.cpp
+	Sprite.cpp
+	ScriptSystem.cpp
+	Script.cpp
 )
 
 target_sources(crepe PUBLIC FILE_SET HEADERS FILES
+	Asset.h
+	Sound.h
+	SoundContext.h
+	ComponentManager.h
+	ComponentManager.hpp
+	Component.h
+	GameObject.h
+	GameObject.hpp
+	Collider.h
+	Rigidbody.h
+	Sprite.h
+	System.h
+	ScriptSystem.h
 )
 
 add_subdirectory(api)
diff --git a/src/crepe/Collider.cpp b/src/crepe/Collider.cpp
new file mode 100644
index 0000000..3f12afd
--- /dev/null
+++ b/src/crepe/Collider.cpp
@@ -0,0 +1,5 @@
+#include "Collider.h"
+
+using namespace crepe;
+
+Collider::Collider(int size) : size(size) {}
diff --git a/src/crepe/Collider.h b/src/crepe/Collider.h
new file mode 100644
index 0000000..120da05
--- /dev/null
+++ b/src/crepe/Collider.h
@@ -0,0 +1,14 @@
+#pragma once
+
+#include "Component.h"
+
+namespace crepe {
+
+class Collider : public Component {
+public:
+	Collider(int size);
+
+	int size;
+};
+
+} // namespace crepe
diff --git a/src/crepe/Component.cpp b/src/crepe/Component.cpp
new file mode 100644
index 0000000..d14159c
--- /dev/null
+++ b/src/crepe/Component.cpp
@@ -0,0 +1,5 @@
+#include "Component.h"
+
+using namespace crepe;
+
+Component::Component() : active(true) {}
diff --git a/src/crepe/Component.h b/src/crepe/Component.h
new file mode 100644
index 0000000..16a4ce5
--- /dev/null
+++ b/src/crepe/Component.h
@@ -0,0 +1,14 @@
+#pragma once
+
+namespace crepe {
+
+class Component {
+public:
+	Component();
+	// TODO: shouldn't this constructor be deleted because this class will never
+	// directly be instantiated?
+
+	bool active;
+};
+
+} // namespace crepe
diff --git a/src/crepe/ComponentManager.cpp b/src/crepe/ComponentManager.cpp
new file mode 100644
index 0000000..9a3fec7
--- /dev/null
+++ b/src/crepe/ComponentManager.cpp
@@ -0,0 +1,24 @@
+#include "ComponentManager.h"
+
+using namespace crepe;
+
+ComponentManager & ComponentManager::get_instance() {
+	static ComponentManager instance;
+	return instance;
+}
+
+void ComponentManager::delete_all_components_of_id(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::delete_all_components() {
+	// 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..2ab9dc8
--- /dev/null
+++ b/src/crepe/ComponentManager.h
@@ -0,0 +1,62 @@
+#pragma once
+
+#include <cstdint>
+#include <memory>
+#include <typeindex>
+#include <unordered_map>
+#include <utility>
+#include <vector>
+
+#include "Component.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 add_component(uint32_t id, Args &&... args);
+	//! Deletes all components of a specific type and id
+	template <typename T>
+	void delete_components_by_id(uint32_t id);
+	//! Deletes all components of a specific type
+	template <typename T>
+	void delete_components();
+	//! Deletes all components of a specific id
+	void delete_all_components_of_id(uint32_t id);
+	//! Deletes all components
+	void delete_all_components();
+
+	//! Get a vector<> of all components at specific type and id
+	template <typename T>
+	std::vector<std::reference_wrapper<T>>
+	get_components_by_id(uint32_t id) const;
+	//! Get a vector<> of all components of a specific type
+	template <typename T>
+	std::vector<std::reference_wrapper<T>> get_components_by_type() 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;
+};
+
+} // namespace crepe
+
+#include "ComponentManager.hpp"
diff --git a/src/crepe/ComponentManager.hpp b/src/crepe/ComponentManager.hpp
new file mode 100644
index 0000000..2ea0c70
--- /dev/null
+++ b/src/crepe/ComponentManager.hpp
@@ -0,0 +1,153 @@
+#pragma once
+
+#include <type_traits>
+
+#include "ComponentManager.h"
+
+namespace crepe {
+
+template <class T, typename... Args>
+void ComponentManager::add_component(uint32_t id, Args &&... args) {
+	using namespace std;
+
+	static_assert(is_base_of<Component, T>::value,
+				  "add_component must recieve a derivative class of Component");
+
+	// Determine the type of T (this is used as the key of the unordered_map<>)
+	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] = vector<vector<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 (arguments directly forwarded). The
+	// constructor must be called by ComponentManager.
+	T * instance = new T(forward<Args>(args)...);
+	// store its unique_ptr in the vector<>
+	components[type][id].push_back(unique_ptr<T>(instance));
+}
+
+template <typename T>
+void ComponentManager::delete_components_by_id(uint32_t id) {
+	using namespace std;
+
+	// Determine the type of T (this is used as the key of the unordered_map<>)
+	type_index type = typeid(T);
+
+	// Find the type (in the unordered_map<>)
+	if (components.find(type) != components.end()) {
+		// Get the correct vector<>
+		vector<vector<unique_ptr<Component>>> & component_array
+			= components[type];
+
+		// Make sure that the id (that we are looking for) is within the boundaries of the vector<>
+		if (id < component_array.size()) {
+			// Clear the whole vector<> of this specific type and id
+			component_array[id].clear();
+		}
+	}
+}
+
+template <typename T>
+void ComponentManager::delete_components() {
+	// 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::get_components_by_id(uint32_t id) const {
+	using namespace std;
+
+	// Determine the type of T (this is used as the key of the unordered_map<>)
+	type_index type = typeid(T);
+
+	// Create an empty vector<>
+	vector<reference_wrapper<T>> component_vector;
+
+	// Find the type (in the unordered_map<>)
+	if (components.find(type) != components.end()) {
+		// Get the correct vector<>
+		const vector<vector<unique_ptr<Component>>> & component_array
+			= components.at(type);
+
+		// Make sure that the id (that we are looking for) is within the boundaries of the vector<>
+		if (id < component_array.size()) {
+			// Loop trough the whole vector<>
+			for (const unique_ptr<Component> & component_ptr :
+				 component_array[id]) {
+				// Cast the unique_ptr to a raw pointer
+				T * casted_component = static_cast<T *>(component_ptr.get());
+
+				// Ensure that the cast was successful
+				if (casted_component) {
+					// Add the dereferenced raw pointer to the vector<>
+					component_vector.push_back(*casted_component);
+				}
+			}
+		}
+	}
+
+	// Return the vector<>
+	return component_vector;
+}
+
+template <typename T>
+std::vector<std::reference_wrapper<T>>
+ComponentManager::get_components_by_type() const {
+	using namespace std;
+
+	// Determine the type of T (this is used as the key of the unordered_map<>)
+	type_index type = typeid(T);
+
+	// Create an empty vector<>
+	vector<reference_wrapper<T>> component_vector;
+	// Set the id to 0 (the id will also be stored in the returned vector<>)
+	// uint32_t id = 0;
+
+	// Find the type (in the unordered_map<>)
+	if (components.find(type) != components.end()) {
+
+		// Get the correct vector<>
+		const vector<vector<unique_ptr<Component>>> & component_array
+			= components.at(type);
+
+		// Loop through the whole vector<>
+		for (const vector<unique_ptr<Component>> & component :
+			 component_array) {
+			// Loop trough the whole vector<>
+			for (const unique_ptr<Component> & component_ptr : component) {
+				// Cast the unique_ptr to a raw pointer
+				T * casted_component = static_cast<T *>(component_ptr.get());
+
+				// Ensure that the cast was successful
+				if (casted_component) {
+					// Pair the dereferenced raw pointer and the id and add it to the vector<>
+					component_vector.emplace_back(ref(*casted_component));
+				}
+			}
+
+			// Increase the id (the id will also be stored in the returned vector<>)
+			//++id;
+		}
+	}
+
+	// Return the vector<>
+	return component_vector;
+}
+
+} // namespace crepe
diff --git a/src/crepe/GameObject.cpp b/src/crepe/GameObject.cpp
new file mode 100644
index 0000000..de3beb6
--- /dev/null
+++ b/src/crepe/GameObject.cpp
@@ -0,0 +1,7 @@
+#include "GameObject.h"
+
+using namespace crepe;
+
+GameObject::GameObject(uint32_t id, std::string name, std::string tag,
+					   int layer)
+	: id(id), name(name), tag(tag), active(true), layer(layer) {}
diff --git a/src/crepe/GameObject.h b/src/crepe/GameObject.h
new file mode 100644
index 0000000..3588d9a
--- /dev/null
+++ b/src/crepe/GameObject.h
@@ -0,0 +1,24 @@
+#pragma once
+
+#include <cstdint>
+#include <string>
+
+namespace crepe {
+
+class GameObject {
+public:
+	GameObject(uint32_t id, std::string name, std::string tag, int layer);
+
+	template <typename T, typename... Args>
+	void add_component(Args &&... args);
+
+	uint32_t id;
+	std::string name;
+	std::string tag;
+	bool active;
+	int layer;
+};
+
+} // namespace crepe
+
+#include "GameObject.hpp"
diff --git a/src/crepe/GameObject.hpp b/src/crepe/GameObject.hpp
new file mode 100644
index 0000000..5966fbf
--- /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::add_component(Args &&... args) {
+	auto & mgr = ComponentManager::get_instance();
+	mgr.add_component<T>(id, std::forward<Args>(args)...);
+}
+
+} // namespace crepe
diff --git a/src/crepe/Rigidbody.cpp b/src/crepe/Rigidbody.cpp
new file mode 100644
index 0000000..495d908
--- /dev/null
+++ b/src/crepe/Rigidbody.cpp
@@ -0,0 +1,6 @@
+#include "Rigidbody.h"
+
+using namespace crepe;
+
+Rigidbody::Rigidbody(int mass, int gravityScale, int bodyType)
+	: mass(mass), gravity_scale(gravityScale), body_type(bodyType) {}
diff --git a/src/crepe/Rigidbody.h b/src/crepe/Rigidbody.h
new file mode 100644
index 0000000..63a8877
--- /dev/null
+++ b/src/crepe/Rigidbody.h
@@ -0,0 +1,16 @@
+#pragma once
+
+#include "Component.h"
+
+namespace crepe {
+
+class Rigidbody : public Component {
+public:
+	Rigidbody(int mass, int gravityScale, int bodyType);
+
+	int mass;
+	int gravity_scale;
+	int body_type;
+};
+
+} // namespace crepe
diff --git a/src/crepe/Script.cpp b/src/crepe/Script.cpp
new file mode 100644
index 0000000..3b83b7c
--- /dev/null
+++ b/src/crepe/Script.cpp
@@ -0,0 +1,6 @@
+#include "Script.h"
+
+using namespace crepe;
+
+void Script::init() {}
+void Script::update() {}
diff --git a/src/crepe/Script.h b/src/crepe/Script.h
new file mode 100644
index 0000000..cdd6814
--- /dev/null
+++ b/src/crepe/Script.h
@@ -0,0 +1,15 @@
+#pragma once
+
+namespace crepe {
+
+class Script {
+protected:
+	virtual void init();
+	virtual void update();
+	// NOTE: additional *events* (like unity's OnDisable and OnEnable) should be
+	// implemented as member methods in derivative user script classes and
+	// registered in init(), otherwise this class will balloon in size with each
+	// added event.
+};
+
+} // namespace crepe
diff --git a/src/crepe/ScriptSystem.cpp b/src/crepe/ScriptSystem.cpp
new file mode 100644
index 0000000..988bb71
--- /dev/null
+++ b/src/crepe/ScriptSystem.cpp
@@ -0,0 +1,15 @@
+#include "util/log.h"
+
+#include "ScriptSystem.h"
+
+using namespace crepe;
+
+ScriptSystem::ScriptSystem() { dbg_trace(); }
+ScriptSystem::~ScriptSystem() { dbg_trace(); }
+
+ScriptSystem & ScriptSystem::get_instance() {
+	static ScriptSystem instance;
+	return instance;
+}
+
+void ScriptSystem::update() { dbg_trace(); }
diff --git a/src/crepe/ScriptSystem.h b/src/crepe/ScriptSystem.h
new file mode 100644
index 0000000..72e360b
--- /dev/null
+++ b/src/crepe/ScriptSystem.h
@@ -0,0 +1,17 @@
+#pragma once
+
+#include "System.h"
+
+namespace crepe {
+
+class ScriptSystem : public System {
+public:
+	static ScriptSystem & get_instance();
+	virtual void update();
+
+private:
+	ScriptSystem();
+	~ScriptSystem();
+};
+
+} // namespace crepe
diff --git a/src/crepe/Sprite.cpp b/src/crepe/Sprite.cpp
new file mode 100644
index 0000000..a5a5e68
--- /dev/null
+++ b/src/crepe/Sprite.cpp
@@ -0,0 +1,8 @@
+#include <string>
+
+#include "Sprite.h"
+
+using namespace crepe;
+using namespace std;
+
+Sprite::Sprite(string path) : path(path) {}
diff --git a/src/crepe/Sprite.h b/src/crepe/Sprite.h
new file mode 100644
index 0000000..143e702
--- /dev/null
+++ b/src/crepe/Sprite.h
@@ -0,0 +1,16 @@
+#pragma once
+
+#include <string>
+
+#include "Component.h"
+
+namespace crepe {
+
+class Sprite : public Component {
+public:
+	Sprite(std::string path);
+
+	std::string path;
+};
+
+} // namespace crepe
diff --git a/src/crepe/System.h b/src/crepe/System.h
new file mode 100644
index 0000000..ecbb7f5
--- /dev/null
+++ b/src/crepe/System.h
@@ -0,0 +1,22 @@
+#pragma once
+
+namespace crepe {
+
+class System {
+public:
+	static System & get_instance();
+	virtual void update() = 0;
+
+protected:
+	System() {};
+	virtual ~System() {};
+
+private:
+	// singleton
+	System(const System &) = delete;
+	System(System &&) = delete;
+	System & operator=(const System &) = delete;
+	System & operator=(System &&) = delete;
+};
+
+} // namespace crepe
diff --git a/src/crepe/api/AudioSource.cpp b/src/crepe/api/AudioSource.cpp
index f0d708a..a5b6d6a 100644
--- a/src/crepe/api/AudioSource.cpp
+++ b/src/crepe/api/AudioSource.cpp
@@ -5,18 +5,18 @@
 
 using namespace crepe::api;
 
-AudioSource::AudioSource(std::unique_ptr<Resource> audio_clip) {
-	this->_sound = std::make_unique<crepe::Sound>(std::move(audio_clip));
+AudioSource::AudioSource(std::unique_ptr<Asset> audio_clip) {
+	this->sound = std::make_unique<crepe::Sound>(std::move(audio_clip));
 }
 
 void AudioSource::play() { return this->play(false); }
 
 void AudioSource::play(bool looping) {
-	this->_sound->set_looping(looping);
-	this->_sound->play();
+	this->sound->set_looping(looping);
+	this->sound->play();
 }
 
 void AudioSource::stop() {
-	this->_sound->pause();
-	this->_sound->rewind();
+	this->sound->pause();
+	this->sound->rewind();
 }
diff --git a/src/crepe/api/AudioSource.h b/src/crepe/api/AudioSource.h
index 4300c48..2d26cda 100644
--- a/src/crepe/api/AudioSource.h
+++ b/src/crepe/api/AudioSource.h
@@ -2,8 +2,8 @@
 
 #include <memory>
 
+#include "Asset.h"
 #include "Component.h"
-#include "Resource.h"
 
 namespace crepe {
 class Sound;
@@ -14,7 +14,7 @@ namespace crepe::api {
 //! Audio source component
 class AudioSource : Component {
 public:
-	AudioSource(std::unique_ptr<Resource> audio_clip);
+	AudioSource(std::unique_ptr<Asset> audio_clip);
 	virtual ~AudioSource() = default;
 
 public:
@@ -26,7 +26,7 @@ public:
 
 public:
 	//! Sample file location
-	std::unique_ptr<Resource> audio_clip;
+	std::unique_ptr<Asset> audio_clip;
 	//! TODO: ?????
 	bool play_on_awake;
 	//! Repeat the current audio clip during playback
@@ -35,7 +35,7 @@ public:
 	float volume;
 
 private:
-	std::unique_ptr<crepe::Sound> _sound;
+	std::unique_ptr<crepe::Sound> sound;
 };
 
 } // namespace crepe::api
diff --git a/src/crepe/api/BehaviorScript.cpp b/src/crepe/api/BehaviorScript.cpp
new file mode 100644
index 0000000..84bfd4c
--- /dev/null
+++ b/src/crepe/api/BehaviorScript.cpp
@@ -0,0 +1,7 @@
+#include "../util/log.h"
+
+#include "BehaviorScript.h"
+
+using namespace crepe::api;
+
+BehaviorScript::BehaviorScript() { dbg_trace(); }
diff --git a/src/crepe/api/BehaviorScript.h b/src/crepe/api/BehaviorScript.h
new file mode 100644
index 0000000..1d05a75
--- /dev/null
+++ b/src/crepe/api/BehaviorScript.h
@@ -0,0 +1,16 @@
+#pragma once
+
+#include "../Component.h"
+#include "../Script.h"
+
+namespace crepe::api {
+
+class BehaviorScript : public Script, public Component {
+	// only allow ComponentManager to instantiate scripts
+	friend class ComponentManager;
+
+protected:
+	BehaviorScript();
+};
+
+} // namespace crepe::api
diff --git a/src/crepe/api/CMakeLists.txt b/src/crepe/api/CMakeLists.txt
index dcac0ae..cecc2f1 100644
--- a/src/crepe/api/CMakeLists.txt
+++ b/src/crepe/api/CMakeLists.txt
@@ -1,23 +1,9 @@
 target_sources(crepe PUBLIC
-	#map_asset.cpp
-	spritesheet.cpp
-	resource_manager.cpp
-	Resource.cpp
-	game.cpp
-	Color.cpp
+	# AudioSource.cpp
+	BehaviorScript.cpp
 )
 
 target_sources(crepe PUBLIC FILE_SET HEADERS FILES
-	Resource.h
-	baseResource.h
-	game.h
-	#map_asset.h
-	spritesheet.h
-	resource_manager.h
-	Component.h
-	AudioSource.h
-	Sprite.h
-	Color.h
-	Transform.h
-	Point.h
+	# AudioSource.h
+	BehaviorScript.h
 )
diff --git a/src/crepe/api/Component.h b/src/crepe/api/Component.h
deleted file mode 100644
index d5e0499..0000000
--- a/src/crepe/api/Component.h
+++ /dev/null
@@ -1,10 +0,0 @@
-#pragma once
-
-namespace crepe::api {
-
-class Component {
-public:
-	bool active;
-};
-
-} // namespace crepe::api
diff --git a/src/crepe/api/Resource.cpp b/src/crepe/api/Resource.cpp
deleted file mode 100644
index f7f2516..0000000
--- a/src/crepe/api/Resource.cpp
+++ /dev/null
@@ -1,18 +0,0 @@
-#include <filesystem>
-#include <iostream>
-#include <iterator>
-
-#include "Resource.h"
-#include "util/log.h"
-
-using namespace crepe::api;
-
-Resource::Resource(const std::string & src) {
-	dbg_trace();
-	this->src = std::filesystem::path(src);
-	this->file = std::ifstream(this->src, std::ios::in | std::ios::binary);
-}
-
-const std::istream & Resource::read() { return this->file; }
-
-const char * Resource::canonical() { return this->src.c_str(); }
diff --git a/src/crepe/api/Resource.h b/src/crepe/api/Resource.h
deleted file mode 100644
index f2b2a0e..0000000
--- a/src/crepe/api/Resource.h
+++ /dev/null
@@ -1,24 +0,0 @@
-#pragma once
-
-#include <fstream>
-#include <iostream>
-#include <string>
-
-namespace crepe::api {
-
-class Resource {
-public:
-	Resource(const std::string & src);
-
-public:
-	//! Get an input stream to the contents of this resource
-	const std::istream & read();
-	//! Get the canonical path to this resource
-	const char * canonical();
-
-private:
-	std::string src;
-	std::ifstream file;
-};
-
-} // namespace crepe::api
diff --git a/src/crepe/facade/Sound.cpp b/src/crepe/facade/Sound.cpp
index e1150ac..64fa281 100644
--- a/src/crepe/facade/Sound.cpp
+++ b/src/crepe/facade/Sound.cpp
@@ -5,17 +5,17 @@
 
 using namespace crepe;
 
-Sound::Sound(std::unique_ptr<api::Resource> res) {
+Sound::Sound(std::unique_ptr<Asset> res) {
 	dbg_trace();
 	this->load(std::move(res));
 }
 
 Sound::Sound(const char * src) {
 	dbg_trace();
-	this->load(std::make_unique<api::Resource>(src));
+	this->load(std::make_unique<Asset>(src));
 }
 
-void Sound::load(std::unique_ptr<api::Resource> res) {
+void Sound::load(std::unique_ptr<Asset> res) {
 	this->sample.load(res->canonical());
 }
 
diff --git a/src/crepe/facade/Sound.h b/src/crepe/facade/Sound.h
index 2f1c924..b11f871 100644
--- a/src/crepe/facade/Sound.h
+++ b/src/crepe/facade/Sound.h
@@ -1,12 +1,11 @@
 #pragma once
 
-#include <soloud.h>
-#include <soloud_wav.h>
+#include <soloud/soloud.h>
+#include <soloud/soloud_wav.h>
 
 #include <memory>
 
-#include "api/Resource.h"
-#include "api/baseResource.h"
+#include "Asset.h"
 
 namespace crepe {
 
@@ -67,10 +66,10 @@ public:
 
 public:
 	Sound(const char * src);
-	Sound(std::unique_ptr<api::Resource> res);
+	Sound(std::unique_ptr<Asset> res);
 
 private:
-	void load(std::unique_ptr<api::Resource> res);
+	void load(std::unique_ptr<Asset> res);
 
 private:
 	SoLoud::Wav sample;
diff --git a/src/crepe/facade/SoundContext.h b/src/crepe/facade/SoundContext.h
index 090966d..d3123d2 100644
--- a/src/crepe/facade/SoundContext.h
+++ b/src/crepe/facade/SoundContext.h
@@ -1,6 +1,6 @@
 #pragma once
 
-#include <soloud.h>
+#include <soloud/soloud.h>
 
 #include "Sound.h"
 
diff --git a/src/crepe/util/log.cpp b/src/crepe/util/log.cpp
index 6829ec3..f91d52c 100644
--- a/src/crepe/util/log.cpp
+++ b/src/crepe/util/log.cpp
@@ -8,10 +8,10 @@
 using namespace crepe::util;
 
 static const char * const LOG_PREFIX[] = {
-	[log_level::debug] = "[DBG] ",
-	[log_level::info] = "[INFO] ",
-	[log_level::warning] = "[WARN] ",
-	[log_level::error] = "[ERR] ",
+	[log_level::DEBUG] = "[DBG] ",
+	[log_level::INFO] = "[INFO] ",
+	[log_level::WARNING] = "[WARN] ",
+	[log_level::ERROR] = "[ERR] ",
 };
 
 static void va_logf(enum log_level level, va_list args, const std::string fmt) {
@@ -38,7 +38,7 @@ static void va_logf(enum log_level level, va_list args, const std::string fmt) {
 void crepe::util::logf(const char * fmt, ...) {
 	va_list args;
 	va_start(args, fmt);
-	va_logf(crepe::util::log_level::debug, args, fmt);
+	va_logf(crepe::util::log_level::DEBUG, args, fmt);
 	va_end(args);
 }
 
diff --git a/src/crepe/util/log.h b/src/crepe/util/log.h
index 4cab338..2b0fbe1 100644
--- a/src/crepe/util/log.h
+++ b/src/crepe/util/log.h
@@ -7,24 +7,27 @@
 
 // utility macros
 #define _crepe_logf_here(fmt, ...) \
-	crepe::util::logf(util::log_level::debug, "%s%s (%s:%d)" fmt "\n", \
+	crepe::util::logf(util::log_level::DEBUG, "%s%s (%s:%d)" fmt "\n", \
 					  crepe::util::color::FG_WHITE, __PRETTY_FUNCTION__, \
 					  __FILE_NAME__, __LINE__, crepe::util::color::RESET, \
 					  __VA_ARGS__)
 
+// very illegal global function-style macros
+// NOLINTBEGIN
 #define dbg_logf(fmt, ...) _crepe_logf_here(": " fmt, __VA_ARGS__)
 #define dbg_log(str) _crepe_logf_here(": %s", str)
 #define dbg_trace() _crepe_logf_here("%s", "")
+// NOLINTEND
 
 #endif
 
 namespace crepe::util {
 
 enum log_level {
-	debug,
-	info,
-	warning,
-	error,
+	DEBUG,
+	INFO,
+	WARNING,
+	ERROR,
 };
 
 void logf(const char * fmt, ...);
diff --git a/src/example/CMakeLists.txt b/src/example/CMakeLists.txt
new file mode 100644
index 0000000..6df4ce7
--- /dev/null
+++ b/src/example/CMakeLists.txt
@@ -0,0 +1,18 @@
+# add_example(target_name [SOURCES...])
+function(add_example target_name)
+	# if SOURCES is not specified
+	if(NOT ARGV1)
+		# A .cpp file with target_name exists, and should be used
+		set(sources ${target_name}.cpp)
+	else()
+		set(sources ${ARGV})
+	endif()
+
+	add_executable(${target_name} EXCLUDE_FROM_ALL ${sources})
+	target_link_libraries(${target_name} PUBLIC crepe)
+endfunction()
+
+add_example(audio_internal)
+add_example(components_internal)
+add_example(script)
+
diff --git a/src/dummy_audio.cpp b/src/example/audio_internal.cpp
index 211a503..1199e2d 100644
--- a/src/dummy_audio.cpp
+++ b/src/example/audio_internal.cpp
@@ -1,5 +1,10 @@
-#include "crepe/facade/Sound.h"
-#include "crepe/util/log.h"
+/** \file
+ * 
+ * Standalone example for usage of the internal \c Sound class.
+ */
+
+#include <crepe/Sound.h>
+#include <crepe/util/log.h>
 
 #include <chrono>
 #include <thread>
diff --git a/src/example/components_internal.cpp b/src/example/components_internal.cpp
new file mode 100644
index 0000000..54ce295
--- /dev/null
+++ b/src/example/components_internal.cpp
@@ -0,0 +1,60 @@
+/** \file
+ * 
+ * Standalone example for usage of the internal ECS
+ */
+
+#include <cassert>
+#include <chrono>
+
+#include <crepe/Collider.h>
+#include <crepe/Component.h>
+#include <crepe/ComponentManager.h>
+#include <crepe/GameObject.h>
+#include <crepe/Rigidbody.h>
+#include <crepe/Sprite.h>
+#include <crepe/util/log.h>
+
+using namespace crepe;
+using namespace std;
+
+#define OBJ_COUNT 100000
+
+int main() {
+	dbg_trace();
+
+	auto & mgr = ComponentManager::get_instance();
+
+	auto start_adding = chrono::high_resolution_clock::now();
+
+	GameObject * game_object[OBJ_COUNT];
+
+	for (int i = 0; i < OBJ_COUNT; ++i) {
+		game_object[i] = new GameObject(i, "Name", "Tag", 0);
+
+		game_object[i]->add_component<Sprite>("test");
+		game_object[i]->add_component<Rigidbody>(0, 0, i);
+		game_object[i]->add_component<Collider>(i);
+	}
+
+	auto stop_adding = chrono::high_resolution_clock::now();
+
+	auto sprites = mgr.get_components_by_type<Sprite>();
+	for (auto sprite : sprites) {
+		assert(sprite.get().path == "test");
+	}
+
+	auto stop_looping = chrono::high_resolution_clock::now();
+
+	for (int i = 0; i < OBJ_COUNT; ++i) {
+		delete game_object[i];
+	}
+
+	auto add_time = chrono::duration_cast<chrono::microseconds>(stop_adding
+																- start_adding);
+	auto loop_time = chrono::duration_cast<chrono::microseconds>(stop_looping
+																 - stop_adding);
+	printf("add time:  %ldus\n", add_time.count());
+	printf("loop time: %ldus\n", loop_time.count());
+
+	return 0;
+}
diff --git a/src/example/script.cpp b/src/example/script.cpp
new file mode 100644
index 0000000..a610b83
--- /dev/null
+++ b/src/example/script.cpp
@@ -0,0 +1,30 @@
+/** \file
+ * 
+ * Standalone example for usage of the script component and system
+ */
+
+#include <crepe/ComponentManager.h>
+#include <crepe/GameObject.h>
+#include <crepe/ScriptSystem.h>
+#include <crepe/util/log.h>
+
+#include <crepe/api/BehaviorScript.h>
+
+using namespace crepe;
+using namespace std;
+
+class MyScript : public api::BehaviorScript {
+	void update() { dbg_trace(); }
+};
+
+int main() {
+	dbg_trace();
+
+	auto obj = GameObject(0, "name", "tag", 0);
+	obj.add_component<MyScript>();
+
+	auto & sys = ScriptSystem::get_instance();
+	sys.update(); // -> MyScript::update
+
+	return 0;
+}
diff --git a/src/makefile b/src/makefile
new file mode 100644
index 0000000..c1ef601
--- /dev/null
+++ b/src/makefile
@@ -0,0 +1,6 @@
+.PHONY: FORCE
+
+FMT += $(shell git ls-files '*.c' '*.cpp' '*.h' '*.hpp')
+format: FORCE
+	clang-tidy -p build/compile_commands.json --fix-errors $(FMT)
+
diff --git a/src/readme.md b/src/readme.md
new file mode 100644
index 0000000..a4a71e7
--- /dev/null
+++ b/src/readme.md
@@ -0,0 +1,33 @@
+# engine source
+
+This folder contains the crêpe engine source files, unit tests, and some toy
+examples. The only target built by default by the CMakeLists.txt in this folder
+is the crêpe shared library object.
+
+Examples (using Ninja):
+
+```
+$ cmake -B build -G Ninja
+$ ninja -C build
+```
+
+Unit tests can be built by explicitly specifying the target `test_main` when
+running the build command:
+
+```
+$ ninja -C build test_main
+```
+
+Each source file in the example/ folder corresponds to a CMake target as well:
+
+```
+$ ninja -C build audio_internal components_internal
+```
+
+For installing crêpe system-wide after building (install must be run with
+elevated privileges):
+
+```
+# ninja -C build install
+```
+
diff --git a/src/test/CMakeLists.txt b/src/test/CMakeLists.txt
new file mode 100644
index 0000000..0d316d6
--- /dev/null
+++ b/src/test/CMakeLists.txt
@@ -0,0 +1,5 @@
+target_sources(test_main PUBLIC
+	dummy.cpp
+	# audio.cpp
+)
+
diff --git a/src/test/audio.cpp b/src/test/audio.cpp
new file mode 100644
index 0000000..d6ff689
--- /dev/null
+++ b/src/test/audio.cpp
@@ -0,0 +1,10 @@
+#include <gtest/gtest.h>
+
+using namespace std;
+using namespace std::chrono_literals;
+
+// using namespace crepe;
+
+// TODO: mock internal audio class
+
+TEST(audio, play) { ASSERT_TRUE(true); }
diff --git a/src/test/dummy.cpp b/src/test/dummy.cpp
new file mode 100644
index 0000000..a00a9c6
--- /dev/null
+++ b/src/test/dummy.cpp
@@ -0,0 +1,3 @@
+#include <gtest/gtest.h>
+
+TEST(dummy, foo) { ASSERT_TRUE(1); }