Merge remote-tracking branch 'origin/master' into max/scenes

49 files changed, 1065 insertions, 236 deletions

diff --git a/Doxyfile b/Doxyfile
index e0a31df..f2714cd 100644
--- a/Doxyfile
+++ b/Doxyfile
@@ -19,15 +19,17 @@ TAB_SIZE = 2
 
 HTML_INDEX_NUM_ENTRIES = 2
 HTML_EXTRA_STYLESHEET = src/doc/style.css
+SHOW_HEADERFILE = NO
 
 USE_MDFILE_AS_MAINPAGE = ./readme.md
 REPEAT_BRIEF = NO
 
-INTERNAL_DOCS = YES
-EXTRACT_PRIVATE = YES
 EXTRACT_STATIC = YES
 HIDE_UNDOC_NAMESPACES = YES
 HIDE_UNDOC_CLASSES = YES
 
 QUIET = YES
 
+# set these to NO for user-only docs
+INTERNAL_DOCS = YES
+EXTRACT_PRIVATE = YES
diff --git a/contributing.md b/contributing.md
index 77a2908..0a90e86 100644
--- a/contributing.md
+++ b/contributing.md
@@ -17,6 +17,7 @@ that you can click on to open them.
   working/compiling version of the project
 - Pull requests for new code include either automated tests for the new code or
   an explanation as to why the code can not (reliably) be tested
+
 <!--
 - TODO: tagging / versions
 -->
@@ -495,6 +496,12 @@ that you can click on to open them.
   </td></tr></table></details>
 - <details><summary>
   Ensure const-correctness
+
+  > [!IMPORTANT]
+  > C-style APIs that work on (possibly internal) references to structs can be
+  > called from const member functions in C++. If the compiler allows you to
+  > mark a function as `const` even though it has side effects, it should
+  > **not** be marked as `const`.
   </summary><table><tr><th>Good</th><th>Bad</th></tr><tr><td>
 
   ```cpp
@@ -795,6 +802,23 @@ that you can click on to open them.
   ```
   </td></tr></table></details>
 - Do not implement new classes as singletons
+- <details><summary>
+  Retrieving the first or last indices for iterators with a known or expected
+  size should be done using <code>.front()</code> or <code>.back()</code>
+  instead of by index
+  </summary><table><tr><th>Good</th><th>Bad</th></tr><tr><td>
+
+  ```cpp
+  vector<int> foo = { 1, 2, 3 };
+  int bar = foo.first();
+  ```
+  </td><td>
+
+  ```cpp
+  vector<int> foo = { 1, 2, 3 };
+  int bar = foo[0];
+  ```
+  </td></tr></table></details>
 
 ## CMakeLists-specific
 
diff --git a/src/crepe/ComponentManager.cpp b/src/crepe/ComponentManager.cpp
index e310577..e4de027 100644
--- a/src/crepe/ComponentManager.cpp
+++ b/src/crepe/ComponentManager.cpp
@@ -26,8 +26,7 @@ void ComponentManager::delete_all_components() {
 }
 
 GameObject ComponentManager::new_object(const string & name, const string & tag,
-										const Vector2 & position, double rotation,
-										double scale) {
+										const vec2 & position, double rotation, double scale) {
 	GameObject object{*this, this->next_id, name, tag, position, rotation, scale};
 	this->next_id++;
 	return object;
diff --git a/src/crepe/ComponentManager.h b/src/crepe/ComponentManager.h
index 0956d1e..1cb0b5f 100644
--- a/src/crepe/ComponentManager.h
+++ b/src/crepe/ComponentManager.h
@@ -5,8 +5,6 @@
 #include <unordered_map>
 #include <vector>
 
-#include "api/Vector2.h"
-
 #include "Component.h"
 #include "types.h"
 
@@ -45,7 +43,7 @@ public:
 	 * \note This method automatically assigns a new entity ID
 	 */
 	GameObject new_object(const std::string & name, const std::string & tag = "",
-						  const Vector2 & position = {0, 0}, double rotation = 0,
+						  const vec2 & position = {0, 0}, double rotation = 0,
 						  double scale = 1);
 
 protected:
diff --git a/src/crepe/Particle.cpp b/src/crepe/Particle.cpp
index 1068cbf..485a0d4 100644
--- a/src/crepe/Particle.cpp
+++ b/src/crepe/Particle.cpp
@@ -2,7 +2,7 @@
 
 using namespace crepe;
 
-void Particle::reset(uint32_t lifespan, const Vector2 & position, const Vector2 & velocity,
+void Particle::reset(uint32_t lifespan, const vec2 & position, const vec2 & velocity,
 					 double angle) {
 	// Initialize the particle state
 	this->time_in_life = 0;
diff --git a/src/crepe/Particle.h b/src/crepe/Particle.h
index 19859fe..d0397c9 100644
--- a/src/crepe/Particle.h
+++ b/src/crepe/Particle.h
@@ -2,7 +2,7 @@
 
 #include <cstdint>
 
-#include "api/Vector2.h"
+#include "types.h"
 
 namespace crepe {
 
@@ -18,11 +18,11 @@ class Particle {
 
 public:
 	//! Position of the particle in 2D space.
-	Vector2 position;
+	vec2 position;
 	//! Velocity vector indicating the speed and direction of the particle.
-	Vector2 velocity;
+	vec2 velocity;
 	//! Accumulated force affecting the particle over time.
-	Vector2 force_over_time;
+	vec2 force_over_time;
 	//! Total lifespan of the particle in milliseconds.
 	uint32_t lifespan;
 	//! Active state of the particle; true if it is in use, false otherwise.
@@ -43,8 +43,7 @@ public:
 	 * \param velocity  The initial velocity of the particle.
 	 * \param angle     The angle of the particle's trajectory or orientation.
 	 */
-	void reset(uint32_t lifespan, const Vector2 & position, const Vector2 & velocity,
-			   double angle);
+	void reset(uint32_t lifespan, const vec2 & position, const vec2 & velocity, double angle);
 	/**
 	 * \brief Updates the particle's state.
 	 *
diff --git a/src/crepe/api/BehaviorScript.h b/src/crepe/api/BehaviorScript.h
index 9d85d4c..d556fe5 100644
--- a/src/crepe/api/BehaviorScript.h
+++ b/src/crepe/api/BehaviorScript.h
@@ -39,11 +39,14 @@ public:
 	 * \brief Set the concrete script of this component
 	 *
 	 * \tparam T Concrete script type (derived from \c crepe::Script)
+	 * \tparam Args Arguments for concrete script constructor
+	 *
+	 * \param args Arguments for concrete script constructor (forwarded using perfect forwarding)
 	 *
 	 * \returns Reference to BehaviorScript component (`*this`)
 	 */
-	template <class T>
-	BehaviorScript & set_script();
+	template <class T, typename... Args>
+	BehaviorScript & set_script(Args &&... args);
 
 protected:
 	//! Script instance
diff --git a/src/crepe/api/BehaviorScript.hpp b/src/crepe/api/BehaviorScript.hpp
index d80321d..bd59337 100644
--- a/src/crepe/api/BehaviorScript.hpp
+++ b/src/crepe/api/BehaviorScript.hpp
@@ -9,13 +9,17 @@
 
 namespace crepe {
 
-template <class T>
-BehaviorScript & BehaviorScript::set_script() {
+template <class T, typename... Args>
+BehaviorScript & BehaviorScript::set_script(Args &&... args) {
 	dbg_trace();
 	static_assert(std::is_base_of<Script, T>::value);
-	Script * s = new T();
+	Script * s = new T(std::forward<Args>(args)...);
+
 	s->game_object_id = this->game_object_id;
-	s->component_manager_ref = &this->component_manager;
+	s->active = this->active;
+	s->component_manager = this->component_manager;
+	s->event_manager = EventManager::get_instance();
+
 	this->script = std::unique_ptr<Script>(s);
 	return *this;
 }
diff --git a/src/crepe/api/CMakeLists.txt b/src/crepe/api/CMakeLists.txt
index 4025a63..50c51ed 100644
--- a/src/crepe/api/CMakeLists.txt
+++ b/src/crepe/api/CMakeLists.txt
@@ -13,7 +13,6 @@ target_sources(crepe PUBLIC
 	Config.cpp
 	Metadata.cpp
 	SceneManager.cpp
-	Vector2.cpp
 	Camera.cpp
 	Animator.cpp
 	EventManager.cpp
@@ -23,6 +22,7 @@ target_sources(crepe PUBLIC
 	LoopTimer.cpp
 	Asset.cpp
 	EventHandler.cpp
+	Script.cpp
 )
 
 target_sources(crepe PUBLIC FILE_SET HEADERS FILES
@@ -36,6 +36,7 @@ target_sources(crepe PUBLIC FILE_SET HEADERS FILES
 	Rigidbody.h
 	Sprite.h
 	Vector2.h
+	Vector2.hpp
 	Color.h
 	Texture.h 
 	AssetManager.h 
diff --git a/src/crepe/api/Event.h b/src/crepe/api/Event.h
index 06cf7f3..b267e3e 100644
--- a/src/crepe/api/Event.h
+++ b/src/crepe/api/Event.h
@@ -1,10 +1,12 @@
-// TODO discussing the location of these events
 #pragma once
+// TODO discussing the location of these events
 
 #include <string>
 
 #include "KeyCodes.h"
 
+namespace crepe {
+
 /**
  * \brief Base class for all event types in the system.
  */
@@ -91,11 +93,7 @@ public:
 /**
  * \brief Event triggered during a collision between objects.
  */
-class CollisionEvent : public Event {
-public:
-	//! Data describing the collision (currently not implemented).
-	// Collision collisionData;
-};
+class CollisionEvent : public Event {};
 
 /**
  * \brief Event triggered when text is submitted, e.g., from a text input.
@@ -110,3 +108,5 @@ public:
  * \brief Event triggered to indicate the application is shutting down.
  */
 class ShutDownEvent : public Event {};
+
+} // namespace crepe
diff --git a/src/crepe/api/EventHandler.hpp b/src/crepe/api/EventHandler.hpp
index 391dcca..050e57e 100644
--- a/src/crepe/api/EventHandler.hpp
+++ b/src/crepe/api/EventHandler.hpp
@@ -1,3 +1,5 @@
+#pragma once
+
 #include <typeindex>
 
 #include "EventHandler.h"
diff --git a/src/crepe/api/EventManager.h b/src/crepe/api/EventManager.h
index 348a04d..1a33023 100644
--- a/src/crepe/api/EventManager.h
+++ b/src/crepe/api/EventManager.h
@@ -77,7 +77,7 @@ public:
 	 * \param channel The channel to trigger the event on (default is CHANNEL_ALL, which triggers on all channels).
 	 */
 	template <typename EventType>
-	void trigger_event(const EventType & event, event_channel_t channel = CHANNEL_ALL);
+	void trigger_event(const EventType & event = {}, event_channel_t channel = CHANNEL_ALL);
 
 	/**
 	 * \brief Queue an event for later processing.
@@ -89,7 +89,7 @@ public:
 	 * \param channel The channel to associate with the event (default is CHANNEL_ALL).
 	 */
 	template <typename EventType>
-	void queue_event(const EventType & event, event_channel_t channel = CHANNEL_ALL);
+	void queue_event(const EventType & event = {}, event_channel_t channel = CHANNEL_ALL);
 
 	/**
 	 * \brief Process all queued events.
diff --git a/src/crepe/api/GameObject.cpp b/src/crepe/api/GameObject.cpp
index 4874426..3c36a21 100644
--- a/src/crepe/api/GameObject.cpp
+++ b/src/crepe/api/GameObject.cpp
@@ -9,7 +9,7 @@ using namespace std;
 
 GameObject::GameObject(ComponentManager & component_manager, game_object_id_t id,
 					   const std::string & name, const std::string & tag,
-					   const Vector2 & position, double rotation, double scale)
+					   const vec2 & position, double rotation, double scale)
 	: id(id),
 	  component_manager(component_manager) {
 
diff --git a/src/crepe/api/GameObject.h b/src/crepe/api/GameObject.h
index 34ef8bb..fcb8d9a 100644
--- a/src/crepe/api/GameObject.h
+++ b/src/crepe/api/GameObject.h
@@ -2,7 +2,6 @@
 
 #include <string>
 
-#include "Vector2.h"
 #include "types.h"
 
 namespace crepe {
@@ -30,7 +29,7 @@ private:
 	 * \param scale The scale of the GameObject
 	 */
 	GameObject(ComponentManager & component_manager, game_object_id_t id,
-			   const std::string & name, const std::string & tag, const Vector2 & position,
+			   const std::string & name, const std::string & tag, const vec2 & position,
 			   double rotation, double scale);
 	//! ComponentManager instances GameObject
 	friend class ComponentManager;
diff --git a/src/crepe/api/ParticleEmitter.h b/src/crepe/api/ParticleEmitter.h
index 33112e1..b83fd61 100644
--- a/src/crepe/api/ParticleEmitter.h
+++ b/src/crepe/api/ParticleEmitter.h
@@ -4,7 +4,7 @@
 
 #include "Component.h"
 #include "Particle.h"
-#include "Vector2.h"
+#include "types.h"
 
 namespace crepe {
 
@@ -30,7 +30,7 @@ public:
 		//! boundary height (midpoint is emitter location)
 		double height = 0.0;
 		//! boundary offset from particle emitter location
-		Vector2 offset;
+		vec2 offset;
 		//! reset on exit or stop velocity and set max postion
 		bool reset_on_exit = false;
 	};
@@ -43,7 +43,7 @@ public:
 	 */
 	struct Data {
 		//! position of the emitter
-		Vector2 position;
+		vec2 position;
 		//! maximum number of particles
 		const unsigned int max_particles = 0;
 		//! rate of particle emission per update (Lowest value = 0.001 any lower is ignored)
@@ -61,7 +61,7 @@ public:
 		//! end Lifespan of particle
 		double end_lifespan = 0.0;
 		//! force over time (physics)
-		Vector2 force_over_time;
+		vec2 force_over_time;
 		//! particle boundary
 		Boundary boundary;
 		//! collection of particles
diff --git a/src/crepe/api/Rigidbody.cpp b/src/crepe/api/Rigidbody.cpp
index 6b87695..576ca45 100644
--- a/src/crepe/api/Rigidbody.cpp
+++ b/src/crepe/api/Rigidbody.cpp
@@ -6,7 +6,7 @@ crepe::Rigidbody::Rigidbody(game_object_id_t id, const Data & data)
 	: Component(id),
 	  data(data) {}
 
-void crepe::Rigidbody::add_force_linear(const Vector2 & force) {
+void crepe::Rigidbody::add_force_linear(const vec2 & force) {
 	this->data.linear_velocity += force;
 }
 
diff --git a/src/crepe/api/Rigidbody.h b/src/crepe/api/Rigidbody.h
index 3e5c7a3..3b0588f 100644
--- a/src/crepe/api/Rigidbody.h
+++ b/src/crepe/api/Rigidbody.h
@@ -2,7 +2,7 @@
 
 #include "../Component.h"
 
-#include "Vector2.h"
+#include "types.h"
 
 namespace crepe {
 
@@ -56,11 +56,11 @@ public:
 		//! Changes if physics apply
 		BodyType body_type = BodyType::DYNAMIC;
 		//! linear velocity of object
-		Vector2 linear_velocity;
+		vec2 linear_velocity;
 		//! maximum linear velocity of object
-		Vector2 max_linear_velocity;
+		vec2 max_linear_velocity;
 		//! linear damping of object
-		Vector2 linear_damping;
+		vec2 linear_damping;
 		//! angular velocity of object
 		double angular_velocity = 0.0;
 		//! max angular velocity of object
@@ -90,7 +90,7 @@ public:
 	 * 
 	 * \param force Vector2 that is added to the linear force.
 	 */
-	void add_force_linear(const Vector2 & force);
+	void add_force_linear(const vec2 & force);
 	/** 
 	 * \brief add a angular force to the Rigidbody.
 	 * 
diff --git a/src/crepe/api/Script.cpp b/src/crepe/api/Script.cpp
new file mode 100644
index 0000000..fcbe4c7
--- /dev/null
+++ b/src/crepe/api/Script.cpp
@@ -0,0 +1,15 @@
+#include "Script.h"
+
+using namespace crepe;
+
+Script::~Script() {
+	EventManager & evmgr = this->event_manager;
+	for (auto id : this->listeners) {
+		evmgr.unsubscribe(id);
+	}
+}
+
+template <>
+void Script::subscribe(const EventHandler<CollisionEvent> & callback) {
+	this->subscribe_internal(callback, this->game_object_id);
+}
diff --git a/src/crepe/api/Script.h b/src/crepe/api/Script.h
index 839d937..a0870cb 100644
--- a/src/crepe/api/Script.h
+++ b/src/crepe/api/Script.h
@@ -3,6 +3,9 @@
 #include <vector>
 
 #include "../types.h"
+#include "../util/OptionalRef.h"
+
+#include "EventManager.h"
 
 namespace crepe {
 
@@ -16,13 +19,23 @@ class ComponentManager;
  * This class is used as a base class for user-defined scripts that can be added to game
  * objects using the \c BehaviorScript component.
  *
- * \note Additional *events* (like Unity's OnDisable and OnEnable) should be implemented as
+ * \info Additional *events* (like Unity's OnDisable and OnEnable) should be implemented as
  * member or lambda methods in derivative user script classes and registered in \c init().
+ *
+ * \warning Concrete scripts are allowed do create a custom constructor, but the utility
+ * functions should not be called inside the constructor as they rely on late references that
+ * are only available after the constructor returns.
+ *
+ * \see feature_script
  */
 class Script {
 protected:
 	/**
-	 * \brief Script initialization function
+	 * \name Interface functions
+	 * \{
+	 */
+	/**
+	 * \brief Script initialization function (empty by default)
 	 *
 	 * This function is called during the ScriptSystem::update() routine *before*
 	 * Script::update() if it (a) has not yet been called and (b) the \c BehaviorScript component
@@ -30,24 +43,31 @@ protected:
 	 */
 	virtual void init() {}
 	/**
-	 * \brief Script update function
+	 * \brief Script update function (empty by default)
 	 *
 	 * This function is called during the ScriptSystem::update() routine if the \c BehaviorScript
 	 * component holding this script instance is active.
 	 */
 	virtual void update() {}
+	//! \}
+
 	//! ScriptSystem calls \c init() and \c update()
 	friend class crepe::ScriptSystem;
 
 protected:
 	/**
-	 * \brief Get single component of type \c T on this game object (utility)
+	 * \name Utility functions
+	 * \{
+	 */
+
+	/**
+	 * \brief Get single component of type \c T on this game object
 	 *
 	 * \tparam T Type of component
 	 *
 	 * \returns Reference to component
 	 *
-	 * \throws nullptr if this game object does not have a component matching type \c T
+	 * \throws std::runtime_error if this game object does not have a component with type \c T
 	 */
 	template <typename T>
 	T & get_component() const;
@@ -55,7 +75,7 @@ protected:
 	// cause compile-time errors
 
 	/**
-	 * \brief Get all components of type \c T on this game object (utility)
+	 * \brief Get all components of type \c T on this game object
 	 *
 	 * \tparam T Type of component
 	 *
@@ -64,25 +84,108 @@ protected:
 	template <typename T>
 	RefVector<T> get_components() const;
 
+	/**
+	 * \brief Log a message using Log::logf
+	 *
+	 * \tparam Args Log::logf parameters
+	 * \param args  Log::logf parameters
+	 */
+	template <typename... Args>
+	void logf(Args &&... args);
+
+	/**
+	 * \brief Subscribe to an event with an explicit channel
+	 * \see EventManager::subscribe
+	 */
+	template <typename EventType>
+	void subscribe(const EventHandler<EventType> & callback, event_channel_t channel);
+	/**
+	 * \brief Subscribe to an event on EventManager::CHANNEL_ALL
+	 * \see EventManager::subscribe
+	 */
+	template <typename EventType>
+	void subscribe(const EventHandler<EventType> & callback);
+
+	//! \}
+
+private:
+	/**
+	 * \brief Internal subscribe function
+	 *
+	 * This function exists so certain template specializations of Script::subscribe can be
+	 * explicitly deleted, and does the following:
+	 * - Wrap the user-provided callback in a check that tests if the parent BehaviorScript
+	 *   component is still active
+	 * - Store the subscriber handle returned by the event manager so this listener is
+	 *   automatically unsubscribed at the end of this Script instance's life
+	 *
+	 * \tparam EventType concrete Event class
+	 * \param callback User-provided callback function
+	 * \param channel Event channel (may have been overridden by template specializations)
+	 */
+	template <typename EventType>
+	void subscribe_internal(const EventHandler<EventType> & callback, event_channel_t channel);
+
 protected:
-	// NOTE: Script must have a constructor without arguments so the game programmer doesn't need
-	// to manually add `using Script::Script` to their concrete script class.
+	// NOTE: This must be the only constructor on Script, see "Late references" below
 	Script() = default;
 	//! Only \c BehaviorScript instantiates Script
 	friend class BehaviorScript;
 
+public:
+	// std::unique_ptr destroys script
+	virtual ~Script();
+
+private:
+	Script(const Script &) = delete;
+	Script(Script &&) = delete;
+	Script & operator=(const Script &) = delete;
+	Script & operator=(Script &&) = delete;
+
 private:
-	// These references are set by BehaviorScript immediately after calling the constructor of
-	// Script.
-	game_object_id_t game_object_id = -1;
-	ComponentManager * component_manager_ref = nullptr;
-	// TODO: use OptionalRef instead of pointer
+	/**
+	 * \name Late references
+	 *
+	 * These references are set by BehaviorScript immediately after calling the constructor of
+	 * Script.
+	 *
+	 * \note Script must have a constructor without arguments so the game programmer doesn't need
+	 * to manually add `using Script::Script` to their concrete script class if they want to
+	 * implement a non-default constructor (e.g. for passing references to their own concrete
+	 * Script classes).
+	 *
+	 * \{
+	 */
+	//! Game object ID of game object parent BehaviorScript is attached to
+	game_object_id_t game_object_id;
+	//! Reference to parent component
+	OptionalRef<bool> active;
+	//! Reference to component manager instance
+	OptionalRef<ComponentManager> component_manager;
+	//! Reference to event manager instance
+	OptionalRef<EventManager> event_manager;
+	//! \}
 
 private:
 	//! Flag to indicate if \c init() has been called already
 	bool initialized = false;
+	//! List of subscribed events
+	std::vector<subscription_t> listeners;
 };
 
+/**
+ * \brief Subscribe to CollisionEvent for the current GameObject
+ *
+ * This is a template specialization for Script::subscribe which automatically sets the event
+ * channel so the callback handler is only called for CollisionEvent events that apply to the
+ * current GameObject the parent BehaviorScript is attached to.
+ */
+template <>
+void Script::subscribe(const EventHandler<CollisionEvent> & callback);
+template <>
+void Script::subscribe(const EventHandler<CollisionEvent> & callback, event_channel_t)
+	= delete;
+
 } // namespace crepe
 
 #include "Script.hpp"
diff --git a/src/crepe/api/Script.hpp b/src/crepe/api/Script.hpp
index a85d814..a2463bf 100644
--- a/src/crepe/api/Script.hpp
+++ b/src/crepe/api/Script.hpp
@@ -20,8 +20,38 @@ T & Script::get_component() const {
 
 template <typename T>
 RefVector<T> Script::get_components() const {
-	auto & mgr = *this->component_manager_ref;
+	ComponentManager & mgr = this->component_manager;
+
 	return mgr.get_components_by_id<T>(this->game_object_id);
 }
 
+template <typename... Args>
+void Script::logf(Args &&... args) {
+	Log::logf(std::forward<Args>(args)...);
+}
+
+template <typename EventType>
+void Script::subscribe_internal(const EventHandler<EventType> & callback,
+								event_channel_t channel) {
+	EventManager & mgr = this->event_manager;
+	subscription_t listener = mgr.subscribe<EventType>(
+		[this, callback](const EventType & data) -> bool {
+			bool & active = this->active;
+			if (!active) return false;
+			return callback(data);
+		},
+		channel);
+	this->listeners.push_back(listener);
+}
+
+template <typename EventType>
+void Script::subscribe(const EventHandler<EventType> & callback, event_channel_t channel) {
+	this->subscribe_internal(callback, channel);
+}
+
+template <typename EventType>
+void Script::subscribe(const EventHandler<EventType> & callback) {
+	this->subscribe_internal(callback, EventManager::CHANNEL_ALL);
+}
+
 } // namespace crepe
diff --git a/src/crepe/api/Transform.cpp b/src/crepe/api/Transform.cpp
index cd944bd..a85b792 100644
--- a/src/crepe/api/Transform.cpp
+++ b/src/crepe/api/Transform.cpp
@@ -4,7 +4,7 @@
 
 using namespace crepe;
 
-Transform::Transform(game_object_id_t id, const Vector2 & point, double rotation, double scale)
+Transform::Transform(game_object_id_t id, const vec2 & point, double rotation, double scale)
 	: Component(id),
 	  position(point),
 	  rotation(rotation),
diff --git a/src/crepe/api/Transform.h b/src/crepe/api/Transform.h
index 18aa293..6243a93 100644
--- a/src/crepe/api/Transform.h
+++ b/src/crepe/api/Transform.h
@@ -1,8 +1,7 @@
 #pragma once
 
-#include "api/Vector2.h"
-
 #include "Component.h"
+#include "types.h"
 
 namespace crepe {
 
@@ -15,7 +14,7 @@ namespace crepe {
 class Transform : public Component {
 public:
 	//! Translation (shift)
-	Vector2 position = {0, 0};
+	vec2 position = {0, 0};
 	//! Rotation, in degrees
 	double rotation = 0;
 	//! Multiplication factor
@@ -28,7 +27,7 @@ protected:
 	 * \param rotation The rotation of the GameObject
 	 * \param scale The scale of the GameObject
 	 */
-	Transform(game_object_id_t id, const Vector2 & point, double rotation, double scale);
+	Transform(game_object_id_t id, const vec2 & point, double rotation, double scale);
 	/**
 	 * There is always exactly one transform component per entity
 	 * \return 1
diff --git a/src/crepe/api/Vector2.cpp b/src/crepe/api/Vector2.cpp
deleted file mode 100644
index 30b968e..0000000
--- a/src/crepe/api/Vector2.cpp
+++ /dev/null
@@ -1,33 +0,0 @@
-#include "Vector2.h"
-
-using namespace crepe;
-
-Vector2 Vector2::operator-(const Vector2 & other) const { return {x - other.x, y - other.y}; }
-
-Vector2 Vector2::operator+(const Vector2 & other) const { return {x + other.x, y + other.y}; }
-
-Vector2 Vector2::operator*(double scalar) const { return {x * scalar, y * scalar}; }
-
-Vector2 & Vector2::operator*=(const Vector2 & other) {
-	x *= other.x;
-	y *= other.y;
-	return *this;
-}
-
-Vector2 & Vector2::operator+=(const Vector2 & other) {
-	x += other.x;
-	y += other.y;
-	return *this;
-}
-
-Vector2 & Vector2::operator+=(double other) {
-	x += other;
-	y += other;
-	return *this;
-}
-
-Vector2 Vector2::operator-() const { return {-x, -y}; }
-
-bool Vector2::operator==(const Vector2 & other) const { return x == other.x && y == other.y; }
-
-bool Vector2::operator!=(const Vector2 & other) const { return !(*this == other); }
diff --git a/src/crepe/api/Vector2.h b/src/crepe/api/Vector2.h
index 2fb6136..c278c87 100644
--- a/src/crepe/api/Vector2.h
+++ b/src/crepe/api/Vector2.h
@@ -3,38 +3,71 @@
 namespace crepe {
 
 //! 2D vector
+template <class T>
 struct Vector2 {
 	//! X component of the vector
-	double x = 0;
+	T x = 0;
 	//! Y component of the vector
-	double y = 0;
+	T y = 0;
 
 	//! Subtracts another vector from this vector and returns the result.
-	Vector2 operator-(const Vector2 & other) const;
+	Vector2 operator-(const Vector2<T> & other) const;
+
+	//! Subtracts a scalar value from both components of this vector and returns the result.
+	Vector2 operator-(T scalar) const;
 
 	//! Adds another vector to this vector and returns the result.
-	Vector2 operator+(const Vector2 & other) const;
+	Vector2 operator+(const Vector2<T> & other) const;
+
+	//! Adds a scalar value to both components of this vector and returns the result.
+	Vector2 operator+(T scalar) const;
+
+	//! Multiplies this vector by another vector element-wise and returns the result.
+	Vector2 operator*(const Vector2<T> & other) const;
 
 	//! Multiplies this vector by a scalar and returns the result.
-	Vector2 operator*(double scalar) const;
+	Vector2 operator*(T scalar) const;
 
-	//! Multiplies this vector by another vector element-wise and updates this vector.
-	Vector2 & operator*=(const Vector2 & other);
+	//! Divides this vector by another vector element-wise and returns the result.
+	Vector2 operator/(const Vector2<T> & other) const;
+
+	//! Divides this vector by a scalar and returns the result.
+	Vector2 operator/(T scalar) const;
 
 	//! Adds another vector to this vector and updates this vector.
-	Vector2 & operator+=(const Vector2 & other);
+	Vector2 & operator+=(const Vector2<T> & other);
 
 	//! Adds a scalar value to both components of this vector and updates this vector.
-	Vector2 & operator+=(double other);
+	Vector2 & operator+=(T other);
+
+	//! Subtracts another vector from this vector and updates this vector.
+	Vector2 & operator-=(const Vector2<T> & other);
+
+	//! Subtracts a scalar value from both components of this vector and updates this vector.
+	Vector2 & operator-=(T other);
+
+	//! Multiplies this vector by another vector element-wise and updates this vector.
+	Vector2 & operator*=(const Vector2<T> & other);
+
+	//! Multiplies this vector by a scalar and updates this vector.
+	Vector2 & operator*=(T other);
+
+	//! Divides this vector by another vector element-wise and updates this vector.
+	Vector2 & operator/=(const Vector2<T> & other);
+
+	//! Divides this vector by a scalar and updates this vector.
+	Vector2 & operator/=(T other);
 
 	//! Returns the negation of this vector.
 	Vector2 operator-() const;
 
 	//! Checks if this vector is equal to another vector.
-	bool operator==(const Vector2 & other) const;
+	bool operator==(const Vector2<T> & other) const;
 
 	//! Checks if this vector is not equal to another vector.
-	bool operator!=(const Vector2 & other) const;
+	bool operator!=(const Vector2<T> & other) const;
 };
 
 } // namespace crepe
+
+#include "Vector2.hpp"
diff --git a/src/crepe/api/Vector2.hpp b/src/crepe/api/Vector2.hpp
new file mode 100644
index 0000000..cad15f8
--- /dev/null
+++ b/src/crepe/api/Vector2.hpp
@@ -0,0 +1,118 @@
+#pragma once
+
+#include "Vector2.h"
+
+namespace crepe {
+
+template <class T>
+Vector2<T> Vector2<T>::operator-(const Vector2<T> & other) const {
+	return {x - other.x, y - other.y};
+}
+
+template <class T>
+Vector2<T> Vector2<T>::operator-(T scalar) const {
+	return {x - scalar, y - scalar};
+}
+
+template <class T>
+Vector2<T> Vector2<T>::operator+(const Vector2<T> & other) const {
+	return {x + other.x, y + other.y};
+}
+
+template <class T>
+Vector2<T> Vector2<T>::operator+(T scalar) const {
+	return {x + scalar, y + scalar};
+}
+
+template <class T>
+Vector2<T> Vector2<T>::operator*(const Vector2<T> & other) const {
+	return {x * other.x, y * other.y};
+}
+
+template <class T>
+Vector2<T> Vector2<T>::operator*(T scalar) const {
+	return {x * scalar, y * scalar};
+}
+
+template <class T>
+Vector2<T> Vector2<T>::operator/(const Vector2<T> & other) const {
+	return {x / other.x, y / other.y};
+}
+
+template <class T>
+Vector2<T> Vector2<T>::operator/(T scalar) const {
+	return {x / scalar, y / scalar};
+}
+
+template <class T>
+Vector2<T> & Vector2<T>::operator+=(const Vector2<T> & other) {
+	x += other.x;
+	y += other.y;
+	return *this;
+}
+
+template <class T>
+Vector2<T> & Vector2<T>::operator+=(T other) {
+	x += other;
+	y += other;
+	return *this;
+}
+
+template <class T>
+Vector2<T> & Vector2<T>::operator-=(const Vector2<T> & other) {
+	x -= other.x;
+	y -= other.y;
+	return *this;
+}
+
+template <class T>
+Vector2<T> & Vector2<T>::operator-=(T other) {
+	x -= other;
+	y -= other;
+	return *this;
+}
+
+template <class T>
+Vector2<T> & Vector2<T>::operator*=(const Vector2<T> & other) {
+	x *= other.x;
+	y *= other.y;
+	return *this;
+}
+
+template <class T>
+Vector2<T> & Vector2<T>::operator*=(T other) {
+	x *= other;
+	y *= other;
+	return *this;
+}
+
+template <class T>
+Vector2<T> & Vector2<T>::operator/=(const Vector2<T> & other) {
+	x /= other.x;
+	y /= other.y;
+	return *this;
+}
+
+template <class T>
+Vector2<T> & Vector2<T>::operator/=(T other) {
+	x /= other;
+	y /= other;
+	return *this;
+}
+
+template <class T>
+Vector2<T> Vector2<T>::operator-() const {
+	return {-x, -y};
+}
+
+template <class T>
+bool Vector2<T>::operator==(const Vector2<T> & other) const {
+	return x == other.x && y == other.y;
+}
+
+template <class T>
+bool Vector2<T>::operator!=(const Vector2<T> & other) const {
+	return !(*this == other);
+}
+
+} // namespace crepe
diff --git a/src/crepe/facade/SDLContext.cpp b/src/crepe/facade/SDLContext.cpp
index 00523a6..b3298a7 100644
--- a/src/crepe/facade/SDLContext.cpp
+++ b/src/crepe/facade/SDLContext.cpp
@@ -104,13 +104,13 @@ SDL_Rect SDLContext::get_src_rect(const Sprite & sprite) const {
 		.h = sprite.sprite_rect.h,
 	};
 }
-SDL_Rect SDLContext::get_dst_rect(const Sprite & sprite, const Vector2 & pos,
+SDL_Rect SDLContext::get_dst_rect(const Sprite & sprite, const vec2 & pos,
 								  const double & scale, const Camera & cam) const {
 
-	double adjusted_x = (pos.x - cam.x) * cam.zoom;
-	double adjusted_y = (pos.y - cam.y) * cam.zoom;
 	double adjusted_w = sprite.sprite_rect.w * scale * cam.zoom;
 	double adjusted_h = sprite.sprite_rect.h * scale * cam.zoom;
+	double adjusted_x = (pos.x - cam.x) * cam.zoom - adjusted_w / 2;
+	double adjusted_y = (pos.y - cam.y) * cam.zoom - adjusted_h / 2;
 
 	return SDL_Rect{
 		.x = static_cast<int>(adjusted_x),
@@ -120,9 +120,8 @@ SDL_Rect SDLContext::get_dst_rect(const Sprite & sprite, const Vector2 & pos,
 	};
 }
 
-void SDLContext::draw_particle(const Sprite & sprite, const Vector2 & pos,
-							   const double & angle, const double & scale,
-							   const Camera & camera) {
+void SDLContext::draw_particle(const Sprite & sprite, const vec2 & pos, const double & angle,
+							   const double & scale, const Camera & camera) {
 
 	SDL_RendererFlip render_flip
 		= (SDL_RendererFlip) ((SDL_FLIP_HORIZONTAL * sprite.flip.flip_x)
diff --git a/src/crepe/facade/SDLContext.h b/src/crepe/facade/SDLContext.h
index 841ffc9..20e30b3 100644
--- a/src/crepe/facade/SDLContext.h
+++ b/src/crepe/facade/SDLContext.h
@@ -12,7 +12,8 @@
 #include "../api/Sprite.h"
 #include "../api/Transform.h"
 #include "api/Camera.h"
-#include "api/Vector2.h"
+
+#include "types.h"
 
 namespace crepe {
 
@@ -120,7 +121,7 @@ private:
 	 */
 	void draw(const Sprite & sprite, const Transform & transform, const Camera & camera);
 
-	void draw_particle(const Sprite & sprite, const Vector2 & pos, const double & angle,
+	void draw_particle(const Sprite & sprite, const vec2 & pos, const double & angle,
 					   const double & scale, const Camera & camera);
 
 	//! Clears the screen, preparing for a new frame.
@@ -153,7 +154,7 @@ private:
 	 * on the camera 
 	 * \return sdl rectangle to draw a dst image to draw on the screen
 	 */
-	SDL_Rect get_dst_rect(const Sprite & sprite, const Vector2 & pos, const double & scale,
+	SDL_Rect get_dst_rect(const Sprite & sprite, const vec2 & pos, const double & scale,
 						  const Camera & cam) const;
 
 private:
diff --git a/src/crepe/system/ParticleSystem.cpp b/src/crepe/system/ParticleSystem.cpp
index fcf7522..0e62a57 100644
--- a/src/crepe/system/ParticleSystem.cpp
+++ b/src/crepe/system/ParticleSystem.cpp
@@ -4,7 +4,6 @@
 
 #include "api/ParticleEmitter.h"
 #include "api/Transform.h"
-#include "api/Vector2.h"
 
 #include "ComponentManager.h"
 #include "ParticleSystem.h"
@@ -42,17 +41,15 @@ void ParticleSystem::update() {
 }
 
 void ParticleSystem::emit_particle(ParticleEmitter & emitter, const Transform & transform) {
-	constexpr double DEG_TO_RAD = M_PI / 180.0;
+	constexpr float DEG_TO_RAD = M_PI / 180.0;
 
-	Vector2 initial_position = emitter.data.position + transform.position;
-	double random_angle
-		= generate_random_angle(emitter.data.min_angle, emitter.data.max_angle);
+	vec2 initial_position = emitter.data.position + transform.position;
+	float random_angle = generate_random_angle(emitter.data.min_angle, emitter.data.max_angle);
 
-	double random_speed
-		= generate_random_speed(emitter.data.min_speed, emitter.data.max_speed);
-	double angle_radians = random_angle * DEG_TO_RAD;
+	float random_speed = generate_random_speed(emitter.data.min_speed, emitter.data.max_speed);
+	float angle_radians = random_angle * DEG_TO_RAD;
 
-	Vector2 velocity
+	vec2 velocity
 		= {random_speed * std::cos(angle_radians), random_speed * std::sin(angle_radians)};
 
 	for (Particle & particle : emitter.data.particles) {
@@ -77,7 +74,7 @@ int ParticleSystem::calculate_update(int count, double emission) const {
 }
 
 void ParticleSystem::check_bounds(ParticleEmitter & emitter, const Transform & transform) {
-	Vector2 offset = emitter.data.boundary.offset + transform.position + emitter.data.position;
+	vec2 offset = emitter.data.boundary.offset + transform.position + emitter.data.position;
 	double half_width = emitter.data.boundary.width / 2.0;
 	double half_height = emitter.data.boundary.height / 2.0;
 
@@ -87,7 +84,7 @@ void ParticleSystem::check_bounds(ParticleEmitter & emitter, const Transform & t
 	const double BOTTOM = offset.y + half_height;
 
 	for (Particle & particle : emitter.data.particles) {
-		const Vector2 & position = particle.position;
+		const vec2 & position = particle.position;
 		bool within_bounds = (position.x >= LEFT && position.x <= RIGHT && position.y >= TOP
 							  && position.y <= BOTTOM);
 
diff --git a/src/crepe/system/PhysicsSystem.cpp b/src/crepe/system/PhysicsSystem.cpp
index bcde431..514a4b3 100644
--- a/src/crepe/system/PhysicsSystem.cpp
+++ b/src/crepe/system/PhysicsSystem.cpp
@@ -34,7 +34,7 @@ void PhysicsSystem::update() {
 						if (rigidbody.data.angular_damping != 0) {
 							rigidbody.data.angular_velocity *= rigidbody.data.angular_damping;
 						}
-						if (rigidbody.data.linear_damping != Vector2{0, 0}) {
+						if (rigidbody.data.linear_damping != vec2{0, 0}) {
 							rigidbody.data.linear_velocity *= rigidbody.data.linear_damping;
 						}
 
diff --git a/src/crepe/system/ScriptSystem.cpp b/src/crepe/system/ScriptSystem.cpp
index c33309c..20a83f7 100644
--- a/src/crepe/system/ScriptSystem.cpp
+++ b/src/crepe/system/ScriptSystem.cpp
@@ -1,5 +1,3 @@
-#include <functional>
-
 #include "../ComponentManager.h"
 #include "../api/BehaviorScript.h"
 #include "../api/Script.h"
@@ -12,30 +10,19 @@ using namespace crepe;
 void ScriptSystem::update() {
 	dbg_trace();
 
-	RefVector<Script> scripts = this->get_scripts();
-
-	for (auto & script_ref : scripts) {
-		Script & script = script_ref.get();
-		if (!script.initialized) {
-			script.init();
-			script.initialized = true;
-		}
-		script.update();
-	}
-}
-
-RefVector<Script> ScriptSystem::get_scripts() const {
-	RefVector<Script> scripts = {};
 	ComponentManager & mgr = this->component_manager;
 	RefVector<BehaviorScript> behavior_scripts = mgr.get_components_by_type<BehaviorScript>();
 
-	for (auto behavior_script_ref : behavior_scripts) {
-		BehaviorScript & behavior_script = behavior_script_ref.get();
+	for (BehaviorScript & behavior_script : behavior_scripts) {
 		if (!behavior_script.active) continue;
+
 		Script * script = behavior_script.script.get();
 		if (script == nullptr) continue;
-		scripts.push_back(*script);
-	}
 
-	return scripts;
+		if (!script->initialized) {
+			script->init();
+			script->initialized = true;
+		}
+		script->update();
+	}
 }
diff --git a/src/crepe/system/ScriptSystem.h b/src/crepe/system/ScriptSystem.h
index 32e1fcd..936e9ca 100644
--- a/src/crepe/system/ScriptSystem.h
+++ b/src/crepe/system/ScriptSystem.h
@@ -2,8 +2,6 @@
 
 #include "System.h"
 
-#include "../types.h"
-
 namespace crepe {
 
 class Script;
@@ -25,15 +23,6 @@ public:
 	 * the \c BehaviorScript instance.
 	 */
 	void update() override;
-
-private:
-	/**
-	 * \brief Aggregate all active \c BehaviorScript components and return a list
-	 * of references to their \c Script instances (utility)
-	 *
-	 * \returns List of active \c Script instances
-	 */
-	RefVector<Script> get_scripts() const;
 };
 
 } // namespace crepe
diff --git a/src/crepe/types.h b/src/crepe/types.h
index 914c76c..17f1619 100644
--- a/src/crepe/types.h
+++ b/src/crepe/types.h
@@ -1,5 +1,7 @@
 #pragma once
 
+#include "api/Vector2.h"
+
 #include <cstdint>
 #include <functional>
 #include <vector>
@@ -13,4 +15,16 @@ typedef uint32_t game_object_id_t;
 template <typename T>
 using RefVector = std::vector<std::reference_wrapper<T>>;
 
+//! Default Vector2<int> type
+typedef Vector2<int> ivec2;
+
+//! Default Vector2<unsigned int> type
+typedef Vector2<unsigned int> uvec2;
+
+//! Default Vector2<float> type
+typedef Vector2<float> vec2;
+
+//! Default Vector2<double> type
+typedef Vector2<double> dvec2;
+
 } // namespace crepe
diff --git a/src/crepe/util/Log.h b/src/crepe/util/Log.h
index d55b11e..fc0bb3a 100644
--- a/src/crepe/util/Log.h
+++ b/src/crepe/util/Log.h
@@ -34,11 +34,11 @@ class Log {
 public:
 	//! Log message severity
 	enum Level {
-		TRACE, //< Include (internal) function calls
-		DEBUG, //< Include dbg_logf output
-		INFO, //< General-purpose messages
-		WARNING, //< Non-fatal errors
-		ERROR, //< Fatal errors
+		TRACE, //!< Include (internal) function calls
+		DEBUG, //!< Include dbg_logf output
+		INFO, //!< General-purpose messages
+		WARNING, //!< Non-fatal errors
+		ERROR, //!< Fatal errors
 	};
 
 	/**
diff --git a/src/doc/feature/scene.dox b/src/doc/feature/scene.dox
index 5d765f9..bac1c87 100644
--- a/src/doc/feature/scene.dox
+++ b/src/doc/feature/scene.dox
@@ -36,7 +36,7 @@ concrete scene to be added.
 #include <crepe/api/LoopManager.h>
 #include <crepe/api/GameObject.h>
 #include <crepe/api/Scene.h>
-#include <crepe/api/Vector2.h>
+#include <crepe/util/types.h>
 
 using namespace crepe;
 
@@ -44,8 +44,8 @@ class MyScene : public Scene {
 public:
 	void load_scene() {
 		ComponentManager & mgr = this->component_manager;
-		GameObject object1 = mgr.new_object("object1", "tag_my_scene", Vector2{0, 0}, 0, 1);
-		GameObject object2 = mgr.new_object("object2", "tag_my_scene", Vector2{1, 0}, 0, 1);
+		GameObject object1 = mgr.new_object("object1", "tag_my_scene", vec2{0, 0}, 0, 1);
+		GameObject object2 = mgr.new_object("object2", "tag_my_scene", vec2{1, 0}, 0, 1);
 	}
 
 	string get_name() const { return "my_scene"; }
diff --git a/src/doc/internal/component.dox b/src/doc/internal/component.dox
new file mode 100644
index 0000000..0dd4cb5
--- /dev/null
+++ b/src/doc/internal/component.dox
@@ -0,0 +1,41 @@
+// vim:ft=doxygen
+namespace crepe {
+/**
+
+\defgroup internal_component Components
+\ingroup internal
+\brief ECS Components
+
+Components are attached to GameObject instances and are composed by the game
+programmer to create specific entities in the game world. While they are
+implemented as C++ classes, components should be treated as C-style structs,
+meaning all members are public and they do not contain functions.
+
+A basic component has the following structure:
+```cpp
+#include <crepe/Component.h>
+
+class MyComponent : public crepe::Component {
+public:
+	// Add your custom component's ininitializer properties after the `id`
+	// parameter. The first parameter is controlled by GameObject::add_component,
+	// while all other parameters are forwarded using std::forward.
+	MyComponent(game_object_id_t id, ...);
+
+	// Optionally define the `get_instances_max` method to limit the amount of
+	// instances of this component per GameObject. The default implementation for
+	// this function returns -1, which means the instance count does not have an
+	// upper limit:
+	virtual int get_instances_max() const { return -1; }
+
+	// Properties
+	// ...
+};
+```
+
+Generally, components are "handled" by \ref internal_system "systems", which may
+optionally change the components' state. Components' state may also be
+controlled by the game programmer through \ref feature_script "scripts".
+
+*/
+}
diff --git a/src/doc/internal/resource.dox b/src/doc/internal/resource.dox
new file mode 100644
index 0000000..56f1de0
--- /dev/null
+++ b/src/doc/internal/resource.dox
@@ -0,0 +1,12 @@
+// vim:ft=doxygen
+namespace crepe {
+/**
+
+\defgroup internal_resource Resources
+\ingroup internal
+\brief Concrete resources
+
+\todo This section is incomplete
+
+*/
+}
diff --git a/src/doc/internal/style.dox b/src/doc/internal/style.dox
new file mode 100644
index 0000000..dad2df0
--- /dev/null
+++ b/src/doc/internal/style.dox
@@ -0,0 +1,9 @@
+// vim:ft=doxygen
+/**
+
+\defgroup internal_style Code style
+\ingroup internal
+\brief Coding conventions
+\include{doc} contributing.md
+
+*/
diff --git a/src/doc/internal/system.dox b/src/doc/internal/system.dox
new file mode 100644
index 0000000..17a101e
--- /dev/null
+++ b/src/doc/internal/system.dox
@@ -0,0 +1,26 @@
+// vim:ft=doxygen
+namespace crepe {
+/**
+
+\defgroup internal_system Systems
+\ingroup internal
+\brief ECS Systems
+
+\todo This section is incomplete
+
+A system is responsible for processing the data stored in \ref
+internal_component "components".
+
+A basic system has the following structure:
+```cpp
+#include <crepe/system/System.h>
+
+class MySystem : public System {
+public:
+	using System::System;
+	void update() override;
+};
+```
+
+*/
+}
diff --git a/src/doc/internals.dox b/src/doc/internals.dox
new file mode 100644
index 0000000..2d2ca56
--- /dev/null
+++ b/src/doc/internals.dox
@@ -0,0 +1,10 @@
+// vim:ft=doxygen
+/**
+
+\defgroup internal Internals
+\brief Internal engine structure and other conventions
+
+\todo This page is incomplete
+\todo Anything about Contexts?
+
+*/
diff --git a/src/doc/layout.xml b/src/doc/layout.xml
index 2244fa7..fb4cc0c 100644
--- a/src/doc/layout.xml
+++ b/src/doc/layout.xml
@@ -1,10 +1,13 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <doxygenlayout version="1.0">
 	<navindex>
-		<tab type="mainpage" visible="yes" title=""/>
+		<tab type="mainpage" visible="yes" title="Intro"/>
+		<tab type="user" url="@ref install" title="Installation"/>
+		<tab type="user" url="@ref feature" title="Features"/>
+		<tab type="user" url="@ref internal" title="Internals"/>
 		<tab type="pages" visible="no" title="" intro=""/>
-		<tab type="topics" visible="yes" title="" intro=""/>
-		<tab type="modules" visible="yes" title="" intro="">
+		<tab type="topics" visible="no" title="" intro=""/>
+		<tab type="modules" visible="no" title="" intro="">
 			<tab type="modulelist" visible="yes" title="" intro=""/>
 			<tab type="modulemembers" visible="yes" title="" intro=""/>
 		</tab>
@@ -12,9 +15,9 @@
 			<tab type="namespacelist" visible="yes" title="" intro=""/>
 			<tab type="namespacemembers" visible="yes" title="" intro=""/>
 		</tab>
-		<tab type="concepts" visible="yes" title="">
+		<tab type="concepts" visible="no" title="">
 		</tab>
-		<tab type="interfaces" visible="yes" title="">
+		<tab type="interfaces" visible="no" title="">
 			<tab type="interfacelist" visible="yes" title="" intro=""/>
 			<tab type="interfaceindex" visible="$ALPHABETICAL_INDEX" title=""/>
 			<tab type="interfacehierarchy" visible="yes" title="" intro=""/>
@@ -25,23 +28,24 @@
 			<tab type="hierarchy" visible="yes" title="" intro=""/>
 			<tab type="classmembers" visible="yes" title="" intro=""/>
 		</tab>
-		<tab type="structs" visible="yes" title="">
+		<tab type="structs" visible="no" title="">
 			<tab type="structlist" visible="yes" title="" intro=""/>
 			<tab type="structindex" visible="$ALPHABETICAL_INDEX" title=""/>
 		</tab>
-		<tab type="exceptions" visible="yes" title="">
+		<tab type="exceptions" visible="no" title="">
 			<tab type="exceptionlist" visible="yes" title="" intro=""/>
 			<tab type="exceptionindex" visible="$ALPHABETICAL_INDEX" title=""/>
 			<tab type="exceptionhierarchy" visible="yes" title="" intro=""/>
 		</tab>
-		<tab type="files" visible="yes" title="">
+		<tab type="files" visible="no" title="">
 			<tab type="filelist" visible="yes" title="" intro=""/>
 			<tab type="globals" visible="yes" title="" intro=""/>
 		</tab>
-		<tab type="examples" visible="yes" title="" intro=""/>
+		<tab type="examples" visible="no" title="" intro=""/>
 	</navindex>
 	<class>
 		<briefdescription visible="yes"/>
+		<detaileddescription title=""/>
 		<includes visible="$SHOW_HEADERFILE"/>
 		<inheritancegraph visible="yes"/>
 		<collaborationgraph visible="yes"/>
@@ -79,7 +83,6 @@
 			<related title="" subtitle=""/>
 			<membergroups visible="yes"/>
 		</memberdecl>
-		<detaileddescription title=""/>
 		<memberdef>
 			<inlineclasses title=""/>
 			<typedefs title=""/>
diff --git a/src/doc/style.css b/src/doc/style.css
index 08bc9f5..daabd39 100644
--- a/src/doc/style.css
+++ b/src/doc/style.css
@@ -2,3 +2,5 @@
 address {
 	display: none;
 }
+
+h2.groupheader { margin-top: revert; }
diff --git a/src/example/rendering_particle.cpp b/src/example/rendering_particle.cpp
index 4571afb..b38e860 100644
--- a/src/example/rendering_particle.cpp
+++ b/src/example/rendering_particle.cpp
@@ -1,5 +1,6 @@
 #include "api/Camera.h"
 #include "system/ParticleSystem.h"
+#include "types.h"
 #include <SDL2/SDL_timer.h>
 #include <crepe/ComponentManager.h>
 
@@ -23,14 +24,14 @@ using namespace std;
 
 int main(int argc, char * argv[]) {
 	ComponentManager mgr;
-	GameObject game_object = mgr.new_object("", "", Vector2{100, 100}, 0, 0.1);
+	GameObject game_object = mgr.new_object("", "", vec2{0, 0}, 0, 0.1);
 	RenderSystem sys{mgr};
 	ParticleSystem psys{mgr};
 
 	Color color(255, 255, 255, 255);
 
 	Sprite & test_sprite = game_object.add_component<Sprite>(
-		make_shared<Texture>("../asset/texture/img.png"), color, FlipSettings{false, false});
+		make_shared<Texture>("asset/texture/img.png"), color, FlipSettings{false, false});
 	test_sprite.order_in_layer = 5;
 
 	auto & test = game_object.add_component<ParticleEmitter>(ParticleEmitter::Data{
@@ -43,11 +44,11 @@ int main(int argc, char * argv[]) {
 		.max_angle = 20,
 		.begin_lifespan = 0,
 		.end_lifespan = 60,
-		.force_over_time = Vector2{0, 0},
+		.force_over_time = vec2{0, 0},
 		.boundary{
 			.width = 1000,
 			.height = 1000,
-			.offset = Vector2{0, 0},
+			.offset = vec2{0, 0},
 			.reset_on_exit = false,
 		},
 		.sprite = test_sprite,
@@ -55,7 +56,7 @@ int main(int argc, char * argv[]) {
 	game_object.add_component<Camera>(Color::WHITE);
 
 	game_object
-		.add_component<Sprite>(make_shared<Texture>("../asset/texture/img.png"), color,
+		.add_component<Sprite>(make_shared<Texture>("asset/texture/img.png"), color,
 							   FlipSettings{false, false})
 		.order_in_layer
 		= 6;
diff --git a/src/test/CMakeLists.txt b/src/test/CMakeLists.txt
index 8cb4232..d310f6a 100644
--- a/src/test/CMakeLists.txt
+++ b/src/test/CMakeLists.txt
@@ -11,5 +11,5 @@ target_sources(test_main PUBLIC
 	SceneManagerTest.cpp
 	ValueBrokerTest.cpp
 	DBTest.cpp
+	Vector2Test.cpp
 )
-
diff --git a/src/test/ECSTest.cpp b/src/test/ECSTest.cpp
index d5a5826..80b936b 100644
--- a/src/test/ECSTest.cpp
+++ b/src/test/ECSTest.cpp
@@ -17,7 +17,7 @@ public:
 };
 
 TEST_F(ECSTest, createGameObject) {
-	GameObject obj = mgr.new_object("body", "person", Vector2{0, 0}, 0, 1);
+	GameObject obj = mgr.new_object("body", "person", vec2{0, 0}, 0, 1);
 
 	vector<reference_wrapper<Metadata>> metadata = mgr.get_components_by_type<Metadata>();
 	vector<reference_wrapper<Transform>> transform = mgr.get_components_by_type<Transform>();
@@ -37,8 +37,8 @@ TEST_F(ECSTest, createGameObject) {
 }
 
 TEST_F(ECSTest, deleteAllGameObjects) {
-	GameObject obj0 = mgr.new_object("body", "person", Vector2{0, 0}, 0, 1);
-	GameObject obj1 = mgr.new_object("body", "person", Vector2{0, 0}, 0, 1);
+	GameObject obj0 = mgr.new_object("body", "person", vec2{0, 0}, 0, 1);
+	GameObject obj1 = mgr.new_object("body", "person", vec2{0, 0}, 0, 1);
 
 	mgr.delete_all_components();
 
@@ -48,7 +48,7 @@ TEST_F(ECSTest, deleteAllGameObjects) {
 	EXPECT_EQ(metadata.size(), 0);
 	EXPECT_EQ(transform.size(), 0);
 
-	GameObject obj2 = mgr.new_object("body2", "person2", Vector2{1, 0}, 5, 1);
+	GameObject obj2 = mgr.new_object("body2", "person2", vec2{1, 0}, 5, 1);
 
 	metadata = mgr.get_components_by_type<Metadata>();
 	transform = mgr.get_components_by_type<Transform>();
@@ -70,8 +70,8 @@ TEST_F(ECSTest, deleteAllGameObjects) {
 }
 
 TEST_F(ECSTest, deleteGameObject) {
-	GameObject obj0 = mgr.new_object("body", "person", Vector2{0, 0}, 0, 1);
-	GameObject obj1 = mgr.new_object("body", "person", Vector2{0, 0}, 0, 1);
+	GameObject obj0 = mgr.new_object("body", "person", vec2{0, 0}, 0, 1);
+	GameObject obj1 = mgr.new_object("body", "person", vec2{0, 0}, 0, 1);
 
 	mgr.delete_all_components_of_id(0);
 
@@ -96,7 +96,7 @@ TEST_F(ECSTest, deleteGameObject) {
 
 TEST_F(ECSTest, manyGameObjects) {
 	for (int i = 0; i < 5000; i++) {
-		GameObject obj = mgr.new_object("body", "person", Vector2{0, 0}, 0, i);
+		GameObject obj = mgr.new_object("body", "person", vec2{0, 0}, 0, i);
 	}
 
 	vector<reference_wrapper<Metadata>> metadata = mgr.get_components_by_type<Metadata>();
@@ -128,7 +128,7 @@ TEST_F(ECSTest, manyGameObjects) {
 
 	for (int i = 0; i < 10000 - 5000; i++) {
 		string tag = "person" + to_string(i);
-		GameObject obj = mgr.new_object("body", tag, Vector2{0, 0}, i, 0);
+		GameObject obj = mgr.new_object("body", tag, vec2{0, 0}, i, 0);
 	}
 
 	metadata = mgr.get_components_by_type<Metadata>();
@@ -139,8 +139,8 @@ TEST_F(ECSTest, manyGameObjects) {
 }
 
 TEST_F(ECSTest, getComponentsByID) {
-	GameObject obj0 = mgr.new_object("body", "person", Vector2{0, 0}, 0, 1);
-	GameObject obj1 = mgr.new_object("body", "person", Vector2{0, 0}, 0, 1);
+	GameObject obj0 = mgr.new_object("body", "person", vec2{0, 0}, 0, 1);
+	GameObject obj1 = mgr.new_object("body", "person", vec2{0, 0}, 0, 1);
 
 	vector<reference_wrapper<Metadata>> metadata = mgr.get_components_by_id<Metadata>(0);
 	vector<reference_wrapper<Transform>> transform = mgr.get_components_by_id<Transform>(1);
@@ -163,15 +163,15 @@ TEST_F(ECSTest, getComponentsByID) {
 
 TEST_F(ECSTest, tooMuchComponents) {
 	try {
-		GameObject obj0 = mgr.new_object("body", "person", Vector2{0, 0}, 0, 1);
-		obj0.add_component<Transform>(Vector2{10, 10}, 0, 1);
+		GameObject obj0 = mgr.new_object("body", "person", vec2{0, 0}, 0, 1);
+		obj0.add_component<Transform>(vec2{10, 10}, 0, 1);
 	} catch (const exception & e) {
 		EXPECT_EQ(e.what(),
 				  string("Exceeded maximum number of instances for this component type"));
 	}
 
 	try {
-		GameObject obj1 = mgr.new_object("body", "person", Vector2{0, 0}, 0, 1);
+		GameObject obj1 = mgr.new_object("body", "person", vec2{0, 0}, 0, 1);
 		obj1.add_component<Metadata>("body", "person");
 	} catch (const exception & e) {
 		EXPECT_EQ(e.what(),
@@ -187,11 +187,11 @@ TEST_F(ECSTest, tooMuchComponents) {
 
 TEST_F(ECSTest, partentChild) {
 	{
-		GameObject body = mgr.new_object("body", "person", Vector2{0, 0}, 0, 1);
-		GameObject right_leg = mgr.new_object("rightLeg", "person", Vector2{1, 1}, 0, 1);
-		GameObject left_leg = mgr.new_object("leftLeg", "person", Vector2{1, 1}, 0, 1);
-		GameObject right_foot = mgr.new_object("rightFoot", "person", Vector2{2, 2}, 0, 1);
-		GameObject left_foot = mgr.new_object("leftFoot", "person", Vector2{2, 2}, 0, 1);
+		GameObject body = mgr.new_object("body", "person", vec2{0, 0}, 0, 1);
+		GameObject right_leg = mgr.new_object("rightLeg", "person", vec2{1, 1}, 0, 1);
+		GameObject left_leg = mgr.new_object("leftLeg", "person", vec2{1, 1}, 0, 1);
+		GameObject right_foot = mgr.new_object("rightFoot", "person", vec2{2, 2}, 0, 1);
+		GameObject left_foot = mgr.new_object("leftFoot", "person", vec2{2, 2}, 0, 1);
 
 		// Set the parent of each GameObject
 		right_foot.set_parent(right_leg);
diff --git a/src/test/ParticleTest.cpp b/src/test/ParticleTest.cpp
index eee022f..8b81e74 100644
--- a/src/test/ParticleTest.cpp
+++ b/src/test/ParticleTest.cpp
@@ -25,7 +25,7 @@ public:
 		std::vector<std::reference_wrapper<Transform>> transforms
 			= mgr.get_components_by_id<Transform>(0);
 		if (transforms.empty()) {
-			GameObject game_object = mgr.new_object("", "", Vector2{0, 0}, 0, 0);
+			GameObject game_object = mgr.new_object("", "", vec2{0, 0}, 0, 0);
 
 			Color color(0, 0, 0, 0);
 			Sprite & test_sprite = game_object.add_component<Sprite>(
@@ -42,11 +42,11 @@ public:
 				.max_angle = 0,
 				.begin_lifespan = 0,
 				.end_lifespan = 0,
-				.force_over_time = Vector2{0, 0},
+				.force_over_time = vec2{0, 0},
 				.boundary{
 					.width = 0,
 					.height = 0,
-					.offset = Vector2{0, 0},
+					.offset = vec2{0, 0},
 					.reset_on_exit = false,
 				},
 				.sprite = test_sprite,
@@ -68,8 +68,8 @@ public:
 		emitter.data.max_angle = 0;
 		emitter.data.begin_lifespan = 0;
 		emitter.data.end_lifespan = 0;
-		emitter.data.force_over_time = Vector2{0, 0};
-		emitter.data.boundary = {0, 0, Vector2{0, 0}, false};
+		emitter.data.force_over_time = vec2{0, 0};
+		emitter.data.boundary = {0, 0, vec2{0, 0}, false};
 		for (auto & particle : emitter.data.particles) {
 			particle.active = false;
 		}
diff --git a/src/test/PhysicsTest.cpp b/src/test/PhysicsTest.cpp
index 1e37c26..33b6020 100644
--- a/src/test/PhysicsTest.cpp
+++ b/src/test/PhysicsTest.cpp
@@ -20,12 +20,12 @@ public:
 		vector<reference_wrapper<Transform>> transforms
 			= mgr.get_components_by_id<Transform>(0);
 		if (transforms.empty()) {
-			auto entity = mgr.new_object("", "", Vector2{0, 0}, 0, 0);
+			auto entity = mgr.new_object("", "", vec2{0, 0}, 0, 0);
 			entity.add_component<Rigidbody>(Rigidbody::Data{
 				.mass = 1,
 				.gravity_scale = 1,
 				.body_type = Rigidbody::BodyType::DYNAMIC,
-				.max_linear_velocity = Vector2{10, 10},
+				.max_linear_velocity = vec2{10, 10},
 				.max_angular_velocity = 10,
 				.constraints = {0, 0},
 				.use_gravity = true,
diff --git a/src/test/SceneManagerTest.cpp b/src/test/SceneManagerTest.cpp
index cd3b827..3b61d5c 100644
--- a/src/test/SceneManagerTest.cpp
+++ b/src/test/SceneManagerTest.cpp
@@ -1,3 +1,4 @@
+#include "types.h"
 #include <crepe/ComponentManager.h>
 #include <crepe/api/GameObject.h>
 #include <crepe/api/Metadata.h>
@@ -14,9 +15,9 @@ class ConcreteScene1 : public Scene {
 public:
 	void load_scene() {
 		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);
+		GameObject object1 = mgr.new_object("scene_1", "tag_scene_1", vec2{0, 0}, 0, 1);
+		GameObject object2 = mgr.new_object("scene_1", "tag_scene_1", vec2{1, 0}, 0, 1);
+		GameObject object3 = mgr.new_object("scene_1", "tag_scene_1", vec2{2, 0}, 0, 1);
 	}
 
 	string get_name() const { return "scene1"; }
@@ -26,10 +27,10 @@ class ConcreteScene2 : public Scene {
 public:
 	void load_scene() {
 		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);
-		GameObject object4 = mgr.new_object("scene_2", "tag_scene_2", Vector2{0, 3}, 0, 1);
+		GameObject object1 = mgr.new_object("scene_2", "tag_scene_2", vec2{0, 0}, 0, 1);
+		GameObject object2 = mgr.new_object("scene_2", "tag_scene_2", vec2{0, 1}, 0, 1);
+		GameObject object3 = mgr.new_object("scene_2", "tag_scene_2", vec2{0, 2}, 0, 1);
+		GameObject object4 = mgr.new_object("scene_2", "tag_scene_2", vec2{0, 3}, 0, 1);
 	}
 
 	string get_name() const { return "scene2"; }
@@ -41,7 +42,7 @@ public:
 
 	void load_scene() {
 		ComponentManager & mgr = this->component_manager;
-		GameObject object1 = mgr.new_object("scene_3", "tag_scene_3", Vector2{0, 0}, 0, 1);
+		GameObject object1 = mgr.new_object("scene_3", "tag_scene_3", vec2{0, 0}, 0, 1);
 	}
 
 	string get_name() const { return name; }
diff --git a/src/test/ScriptTest.cpp b/src/test/ScriptTest.cpp
index 19fef6d..78d5061 100644
--- a/src/test/ScriptTest.cpp
+++ b/src/test/ScriptTest.cpp
@@ -6,6 +6,8 @@
 
 #include <crepe/ComponentManager.h>
 #include <crepe/api/BehaviorScript.h>
+#include <crepe/api/Event.h>
+#include <crepe/api/EventManager.h>
 #include <crepe/api/GameObject.h>
 #include <crepe/api/Script.h>
 #include <crepe/api/Vector2.h>
@@ -15,58 +17,113 @@ using namespace std;
 using namespace crepe;
 using namespace testing;
 
+class MyEvent : public Event {};
+
 class ScriptTest : public Test {
 public:
 	ComponentManager component_manager{};
 	ScriptSystem system{component_manager};
+	EventManager & event_manager = EventManager::get_instance();
 
 	class MyScript : public Script {
 		// NOTE: default (private) visibility of init and update shouldn't cause
 		// issues!
-		void init() { this->init_count++; }
+		void init() {
+			this->init_count++;
+
+			subscribe<MyEvent>([this](const MyEvent &) {
+				this->event_count++;
+				return true;
+			});
+
+			// init should never be called more than once
+			EXPECT_LE(this->init_count, 1);
+		}
 		void update() { this->update_count++; }
 
 	public:
 		unsigned init_count = 0;
 		unsigned update_count = 0;
+		unsigned event_count = 0;
 	};
 
-	BehaviorScript * behaviorscript_ref = nullptr;
-	MyScript * script_ref = nullptr;
+	OptionalRef<BehaviorScript> behaviorscript;
+	OptionalRef<MyScript> script;
 
 	void SetUp() override {
 		auto & mgr = this->component_manager;
 		GameObject entity = mgr.new_object("name");
 		BehaviorScript & component = entity.add_component<BehaviorScript>();
 
-		this->behaviorscript_ref = &component;
-		EXPECT_EQ(this->behaviorscript_ref->script.get(), nullptr);
+		this->behaviorscript = component;
+		ASSERT_TRUE(this->behaviorscript);
+		EXPECT_EQ(component.script.get(), nullptr);
 		component.set_script<MyScript>();
-		ASSERT_NE(this->behaviorscript_ref->script.get(), nullptr);
+		ASSERT_NE(component.script.get(), nullptr);
 
-		this->script_ref = (MyScript *) this->behaviorscript_ref->script.get();
-		ASSERT_NE(this->script_ref, nullptr);
+		this->script = *(MyScript *) component.script.get();
+		ASSERT_TRUE(this->script);
+
+		// sanity
+		MyScript & script = this->script;
+		ASSERT_EQ(script.init_count, 0);
+		ASSERT_EQ(script.update_count, 0);
+		ASSERT_EQ(script.event_count, 0);
 	}
 };
 
 TEST_F(ScriptTest, Default) {
-	EXPECT_EQ(0, this->script_ref->init_count);
-	EXPECT_EQ(0, this->script_ref->update_count);
+	MyScript & script = this->script;
+	EXPECT_EQ(0, script.init_count);
+	EXPECT_EQ(0, script.update_count);
+	EXPECT_EQ(0, script.event_count);
 }
 
 TEST_F(ScriptTest, UpdateOnce) {
-	EXPECT_EQ(0, this->script_ref->init_count);
-	EXPECT_EQ(0, this->script_ref->update_count);
+	MyScript & script = this->script;
 
-	this->system.update();
-	EXPECT_EQ(1, this->script_ref->init_count);
-	EXPECT_EQ(1, this->script_ref->update_count);
+	system.update();
+	EXPECT_EQ(1, script.init_count);
+	EXPECT_EQ(1, script.update_count);
+	EXPECT_EQ(0, script.event_count);
 }
 
-TEST_F(ScriptTest, ListScripts) {
-	size_t script_count = 0;
-	for (auto & _ : this->system.get_scripts()) {
-		script_count++;
-	}
-	ASSERT_EQ(1, script_count);
+TEST_F(ScriptTest, UpdateInactive) {
+	BehaviorScript & behaviorscript = this->behaviorscript;
+	MyScript & script = this->script;
+
+	behaviorscript.active = false;
+	system.update();
+	EXPECT_EQ(0, script.init_count);
+	EXPECT_EQ(0, script.update_count);
+	EXPECT_EQ(0, script.event_count);
+
+	behaviorscript.active = true;
+	system.update();
+	EXPECT_EQ(1, script.init_count);
+	EXPECT_EQ(1, script.update_count);
+	EXPECT_EQ(0, script.event_count);
+}
+
+TEST_F(ScriptTest, EventInactive) {
+	BehaviorScript & behaviorscript = this->behaviorscript;
+	MyScript & script = this->script;
+	EventManager & evmgr = this->event_manager;
+
+	system.update();
+	behaviorscript.active = false;
+	EXPECT_EQ(1, script.init_count);
+	EXPECT_EQ(1, script.update_count);
+	EXPECT_EQ(0, script.event_count);
+
+	evmgr.trigger_event<MyEvent>();
+	EXPECT_EQ(1, script.init_count);
+	EXPECT_EQ(1, script.update_count);
+	EXPECT_EQ(0, script.event_count);
+
+	behaviorscript.active = true;
+	evmgr.trigger_event<MyEvent>();
+	EXPECT_EQ(1, script.init_count);
+	EXPECT_EQ(1, script.update_count);
+	EXPECT_EQ(1, script.event_count);
 }
diff --git a/src/test/Vector2Test.cpp b/src/test/Vector2Test.cpp
new file mode 100644
index 0000000..17bca41
--- /dev/null
+++ b/src/test/Vector2Test.cpp
@@ -0,0 +1,384 @@
+#include <gtest/gtest.h>
+
+#include <crepe/api/Vector2.h>
+
+using namespace crepe;
+
+class Vector2Test : public ::testing::Test {
+public:
+	Vector2<int> int_vec1;
+	Vector2<int> int_vec2;
+	Vector2<double> double_vec1;
+	Vector2<double> double_vec2;
+	Vector2<long> long_vec1;
+	Vector2<long> long_vec2;
+	Vector2<float> float_vec1;
+	Vector2<float> float_vec2;
+
+	void SetUp() override {
+		int_vec1 = {1, 2};
+		int_vec2 = {3, 4};
+		double_vec1 = {1.0, 2.0};
+		double_vec2 = {3.0, 4.0};
+		long_vec1 = {1, 2};
+		long_vec2 = {3, 4};
+		float_vec1 = {1.0f, 2.0f};
+		float_vec2 = {3.0f, 4.0f};
+	}
+};
+
+TEST_F(Vector2Test, Subtract) {
+	Vector2<int> result = int_vec1 - int_vec2;
+	EXPECT_EQ(result.x, -2);
+	EXPECT_EQ(result.y, -2);
+
+	Vector2<double> result2 = double_vec1 - double_vec2;
+	EXPECT_FLOAT_EQ(result2.x, -2.0);
+	EXPECT_FLOAT_EQ(result2.y, -2.0);
+
+	Vector2<long> result3 = long_vec1 - long_vec2;
+	EXPECT_EQ(result3.x, -2);
+	EXPECT_EQ(result3.y, -2);
+
+	Vector2<float> result4 = float_vec1 - float_vec2;
+	EXPECT_FLOAT_EQ(result4.x, -2.0f);
+	EXPECT_FLOAT_EQ(result4.y, -2.0f);
+}
+
+TEST_F(Vector2Test, SubtractScalar) {
+	Vector2<int> result = int_vec1 - 1;
+	EXPECT_EQ(result.x, 0);
+	EXPECT_EQ(result.y, 1);
+
+	Vector2<double> result2 = double_vec1 - 1.0;
+	EXPECT_FLOAT_EQ(result2.x, 0.0);
+	EXPECT_FLOAT_EQ(result2.y, 1.0);
+
+	Vector2<long> result3 = long_vec1 - 1;
+	EXPECT_EQ(result3.x, 0);
+	EXPECT_EQ(result3.y, 1);
+
+	Vector2<float> result4 = float_vec1 - 1.0f;
+	EXPECT_FLOAT_EQ(result4.x, 0.0f);
+	EXPECT_FLOAT_EQ(result4.y, 1.0f);
+}
+
+TEST_F(Vector2Test, Add) {
+	Vector2<int> result = int_vec1 + int_vec2;
+	EXPECT_EQ(result.x, 4);
+	EXPECT_EQ(result.y, 6);
+
+	Vector2<double> result2 = double_vec1 + double_vec2;
+	EXPECT_FLOAT_EQ(result2.x, 4.0);
+	EXPECT_FLOAT_EQ(result2.y, 6.0);
+
+	Vector2<long> result3 = long_vec1 + long_vec2;
+	EXPECT_EQ(result3.x, 4);
+	EXPECT_EQ(result3.y, 6);
+
+	Vector2<float> result4 = float_vec1 + float_vec2;
+	EXPECT_FLOAT_EQ(result4.x, 4.0f);
+	EXPECT_FLOAT_EQ(result4.y, 6.0f);
+}
+
+TEST_F(Vector2Test, AddScalar) {
+	Vector2<int> result = int_vec1 + 1;
+	EXPECT_EQ(result.x, 2);
+	EXPECT_EQ(result.y, 3);
+
+	Vector2<double> result2 = double_vec1 + 1.0;
+	EXPECT_FLOAT_EQ(result2.x, 2.0);
+	EXPECT_FLOAT_EQ(result2.y, 3.0);
+
+	Vector2<long> result3 = long_vec1 + 1;
+	EXPECT_EQ(result3.x, 2);
+	EXPECT_EQ(result3.y, 3);
+
+	Vector2<float> result4 = float_vec1 + 1.0f;
+	EXPECT_FLOAT_EQ(result4.x, 2.0f);
+	EXPECT_FLOAT_EQ(result4.y, 3.0f);
+}
+
+TEST_F(Vector2Test, Multiply) {
+	Vector2<int> result = int_vec1 * int_vec2;
+	EXPECT_EQ(result.x, 3);
+	EXPECT_EQ(result.y, 8);
+
+	Vector2<double> result2 = double_vec1 * double_vec2;
+	EXPECT_FLOAT_EQ(result2.x, 3.0);
+	EXPECT_FLOAT_EQ(result2.y, 8.0);
+
+	Vector2<long> result3 = long_vec1 * long_vec2;
+	EXPECT_EQ(result3.x, 3);
+	EXPECT_EQ(result3.y, 8);
+
+	Vector2<float> result4 = float_vec1 * float_vec2;
+	EXPECT_FLOAT_EQ(result4.x, 3.0f);
+	EXPECT_FLOAT_EQ(result4.y, 8.0f);
+}
+
+TEST_F(Vector2Test, MultiplyScalar) {
+	Vector2<int> result = int_vec1 * 2;
+	EXPECT_EQ(result.x, 2);
+	EXPECT_EQ(result.y, 4);
+
+	Vector2<double> result2 = double_vec1 * 2.0;
+	EXPECT_FLOAT_EQ(result2.x, 2.0);
+	EXPECT_FLOAT_EQ(result2.y, 4.0);
+
+	Vector2<long> result3 = long_vec1 * 2;
+	EXPECT_EQ(result3.x, 2);
+	EXPECT_EQ(result3.y, 4);
+
+	Vector2<float> result4 = float_vec1 * 2.0f;
+	EXPECT_FLOAT_EQ(result4.x, 2.0f);
+	EXPECT_FLOAT_EQ(result4.y, 4.0f);
+}
+
+TEST_F(Vector2Test, Divide) {
+	Vector2<int> result = int_vec1 / int_vec2;
+	EXPECT_EQ(result.x, 0);
+	EXPECT_EQ(result.y, 0);
+
+	Vector2<double> result2 = double_vec1 / double_vec2;
+	EXPECT_FLOAT_EQ(result2.x, 0.33333333333333331);
+	EXPECT_FLOAT_EQ(result2.y, 0.5);
+
+	Vector2<long> result3 = long_vec1 / long_vec2;
+	EXPECT_EQ(result3.x, 0);
+	EXPECT_EQ(result3.y, 0);
+
+	Vector2<float> result4 = float_vec1 / float_vec2;
+	EXPECT_FLOAT_EQ(result4.x, 0.333333343f);
+	EXPECT_FLOAT_EQ(result4.y, 0.5f);
+}
+
+TEST_F(Vector2Test, DivideScalar) {
+	Vector2<int> result = int_vec1 / 2;
+	EXPECT_EQ(result.x, 0);
+	EXPECT_EQ(result.y, 1);
+
+	Vector2<double> result2 = double_vec1 / 2.0;
+	EXPECT_FLOAT_EQ(result2.x, 0.5);
+	EXPECT_FLOAT_EQ(result2.y, 1.0);
+
+	Vector2<long> result3 = long_vec1 / 2;
+	EXPECT_EQ(result3.x, 0);
+	EXPECT_EQ(result3.y, 1);
+
+	Vector2<float> result4 = float_vec1 / 2.0f;
+	EXPECT_FLOAT_EQ(result4.x, 0.5f);
+	EXPECT_FLOAT_EQ(result4.y, 1.0f);
+}
+
+TEST_F(Vector2Test, AddChain) {
+	Vector2<int> result = int_vec1;
+	result += int_vec2;
+	EXPECT_EQ(result.x, 4);
+	EXPECT_EQ(result.y, 6);
+
+	Vector2<double> result2 = double_vec1;
+	result2 += double_vec2;
+	EXPECT_FLOAT_EQ(result2.x, 4.0);
+	EXPECT_FLOAT_EQ(result2.y, 6.0);
+
+	Vector2<long> result3 = long_vec1;
+	result3 += long_vec2;
+	EXPECT_EQ(result3.x, 4);
+	EXPECT_EQ(result3.y, 6);
+
+	Vector2<float> result4 = float_vec1;
+	result4 += float_vec2;
+	EXPECT_FLOAT_EQ(result4.x, 4.0f);
+	EXPECT_FLOAT_EQ(result4.y, 6.0f);
+}
+
+TEST_F(Vector2Test, AddScalarChain) {
+	Vector2<int> result = int_vec1;
+	result += 1;
+	EXPECT_EQ(result.x, 2);
+	EXPECT_EQ(result.y, 3);
+
+	Vector2<double> result2 = double_vec1;
+	result2 += 1.0;
+	EXPECT_FLOAT_EQ(result2.x, 2.0);
+	EXPECT_FLOAT_EQ(result2.y, 3.0);
+
+	Vector2<long> result3 = long_vec1;
+	result3 += 1;
+	EXPECT_EQ(result3.x, 2);
+	EXPECT_EQ(result3.y, 3);
+
+	Vector2<float> result4 = float_vec1;
+	result4 += 1.0f;
+	EXPECT_FLOAT_EQ(result4.x, 2.0f);
+	EXPECT_FLOAT_EQ(result4.y, 3.0f);
+}
+
+TEST_F(Vector2Test, SubtractChain) {
+	Vector2<int> result = int_vec1;
+	result -= int_vec2;
+	EXPECT_EQ(result.x, -2);
+	EXPECT_EQ(result.y, -2);
+
+	Vector2<double> result2 = double_vec1;
+	result2 -= double_vec2;
+	EXPECT_FLOAT_EQ(result2.x, -2.0);
+	EXPECT_FLOAT_EQ(result2.y, -2.0);
+
+	Vector2<long> result3 = long_vec1;
+	result3 -= long_vec2;
+	EXPECT_EQ(result3.x, -2);
+	EXPECT_EQ(result3.y, -2);
+
+	Vector2<float> result4 = float_vec1;
+	result4 -= float_vec2;
+	EXPECT_FLOAT_EQ(result4.x, -2.0f);
+	EXPECT_FLOAT_EQ(result4.y, -2.0f);
+}
+
+TEST_F(Vector2Test, SubtractScalarChain) {
+	Vector2<int> result = int_vec1;
+	result -= 1;
+	EXPECT_EQ(result.x, 0);
+	EXPECT_EQ(result.y, 1);
+
+	Vector2<double> result2 = double_vec1;
+	result2 -= 1.0;
+	EXPECT_FLOAT_EQ(result2.x, 0.0);
+	EXPECT_FLOAT_EQ(result2.y, 1.0);
+
+	Vector2<long> result3 = long_vec1;
+	result3 -= 1;
+	EXPECT_EQ(result3.x, 0);
+	EXPECT_EQ(result3.y, 1);
+
+	Vector2<float> result4 = float_vec1;
+	result4 -= 1.0f;
+	EXPECT_FLOAT_EQ(result4.x, 0.0f);
+	EXPECT_FLOAT_EQ(result4.y, 1.0f);
+}
+
+TEST_F(Vector2Test, MultiplyChain) {
+	Vector2<int> result = int_vec1;
+	result *= int_vec2;
+	EXPECT_EQ(result.x, 3);
+	EXPECT_EQ(result.y, 8);
+
+	Vector2<double> result2 = double_vec1;
+	result2 *= double_vec2;
+	EXPECT_FLOAT_EQ(result2.x, 3.0);
+	EXPECT_FLOAT_EQ(result2.y, 8.0);
+
+	Vector2<long> result3 = long_vec1;
+	result3 *= long_vec2;
+	EXPECT_EQ(result3.x, 3);
+	EXPECT_EQ(result3.y, 8);
+
+	Vector2<float> result4 = float_vec1;
+	result4 *= float_vec2;
+	EXPECT_FLOAT_EQ(result4.x, 3.0f);
+	EXPECT_FLOAT_EQ(result4.y, 8.0f);
+}
+
+TEST_F(Vector2Test, MultiplyScalarChain) {
+	Vector2<int> result = int_vec1;
+	result *= 2;
+	EXPECT_EQ(result.x, 2);
+	EXPECT_EQ(result.y, 4);
+
+	Vector2<double> result2 = double_vec1;
+	result2 *= 2.0;
+	EXPECT_FLOAT_EQ(result2.x, 2.0);
+	EXPECT_FLOAT_EQ(result2.y, 4.0);
+
+	Vector2<long> result3 = long_vec1;
+	result3 *= 2;
+	EXPECT_EQ(result3.x, 2);
+	EXPECT_EQ(result3.y, 4);
+
+	Vector2<float> result4 = float_vec1;
+	result4 *= 2.0f;
+	EXPECT_FLOAT_EQ(result4.x, 2.0f);
+	EXPECT_FLOAT_EQ(result4.y, 4.0f);
+}
+
+TEST_F(Vector2Test, DivideChain) {
+	Vector2<int> result = int_vec1;
+	result /= int_vec2;
+	EXPECT_EQ(result.x, 0);
+	EXPECT_EQ(result.y, 0);
+
+	Vector2<double> result2 = double_vec1;
+	result2 /= double_vec2;
+	EXPECT_FLOAT_EQ(result2.x, 0.33333333333333331);
+	EXPECT_FLOAT_EQ(result2.y, 0.5);
+
+	Vector2<long> result3 = long_vec1;
+	result3 /= long_vec2;
+	EXPECT_EQ(result3.x, 0);
+	EXPECT_EQ(result3.y, 0);
+
+	Vector2<float> result4 = float_vec1;
+	result4 /= float_vec2;
+	EXPECT_FLOAT_EQ(result4.x, 0.333333343f);
+	EXPECT_FLOAT_EQ(result4.y, 0.5f);
+}
+
+TEST_F(Vector2Test, DivideScalarChain) {
+	Vector2<int> result = int_vec1;
+	result /= 2;
+	EXPECT_EQ(result.x, 0);
+	EXPECT_EQ(result.y, 1);
+
+	Vector2<double> result2 = double_vec1;
+	result2 /= 2.0;
+	EXPECT_FLOAT_EQ(result2.x, 0.5);
+	EXPECT_FLOAT_EQ(result2.y, 1.0);
+
+	Vector2<long> result3 = long_vec1;
+	result3 /= 2;
+	EXPECT_EQ(result3.x, 0);
+	EXPECT_EQ(result3.y, 1);
+
+	Vector2<float> result4 = float_vec1;
+	result4 /= 2.0f;
+	EXPECT_FLOAT_EQ(result4.x, 0.5f);
+	EXPECT_FLOAT_EQ(result4.y, 1.0f);
+}
+
+TEST_F(Vector2Test, Negatation) {
+	Vector2<int> result = -int_vec1;
+	EXPECT_EQ(result.x, -1);
+	EXPECT_EQ(result.y, -2);
+
+	Vector2<double> result2 = -double_vec1;
+	EXPECT_FLOAT_EQ(result2.x, -1.0);
+	EXPECT_FLOAT_EQ(result2.y, -2.0);
+
+	Vector2<long> result3 = -long_vec1;
+	EXPECT_EQ(result3.x, -1);
+	EXPECT_EQ(result3.y, -2);
+
+	Vector2<float> result4 = -float_vec1;
+	EXPECT_FLOAT_EQ(result4.x, -1.0f);
+	EXPECT_FLOAT_EQ(result4.y, -2.0f);
+}
+
+TEST_F(Vector2Test, Equals) {
+	EXPECT_TRUE(int_vec1 == int_vec1);
+	EXPECT_FALSE(int_vec1 == int_vec2);
+	EXPECT_TRUE(double_vec1 == double_vec1);
+	EXPECT_FALSE(double_vec1 == double_vec2);
+	EXPECT_TRUE(long_vec1 == long_vec1);
+	EXPECT_FALSE(long_vec1 == long_vec2);
+}
+
+TEST_F(Vector2Test, NotEquals) {
+	EXPECT_FALSE(int_vec1 != int_vec1);
+	EXPECT_TRUE(int_vec1 != int_vec2);
+	EXPECT_FALSE(double_vec1 != double_vec1);
+	EXPECT_TRUE(double_vec1 != double_vec2);
+	EXPECT_FALSE(long_vec1 != long_vec1);
+	EXPECT_TRUE(long_vec1 != long_vec2);
+}