Merge branch 'master' into niels/UI

16 files changed, 451 insertions, 127 deletions

diff --git a/src/crepe/api/AI.cpp b/src/crepe/api/AI.cpp
new file mode 100644
index 0000000..2195249
--- /dev/null
+++ b/src/crepe/api/AI.cpp
@@ -0,0 +1,89 @@
+#include <stdexcept>
+#include <type_traits>
+
+#include "AI.h"
+#include "types.h"
+
+namespace crepe {
+
+AI::AI(game_object_id_t id, float max_force) : Component(id), max_force(max_force) {}
+
+void AI::make_circle_path(float radius, const vec2 & center, float start_angle,
+						  bool clockwise) {
+	if (radius <= 0) {
+		throw std::runtime_error("Radius must be greater than 0");
+	}
+
+	// The step size is determined by the radius (step size is in radians)
+	float step = RADIUS_TO_STEP / radius;
+	// Force at least MIN_STEP steps (in case of a small radius)
+	if (step > 2 * M_PI / MIN_STEP) {
+		step = 2 * M_PI / MIN_STEP;
+	}
+	// The path node distance is determined by the step size and the radius
+	this->path_node_distance = radius * step * PATH_NODE_DISTANCE_FACTOR;
+
+	if (clockwise) {
+		for (float i = start_angle; i < 2 * M_PI + start_angle; i += step) {
+			path.push_back(vec2{static_cast<float>(center.x + radius * cos(i)),
+								static_cast<float>(center.y + radius * sin(i))});
+		}
+	} else {
+		for (float i = start_angle; i > start_angle - 2 * M_PI; i -= step) {
+			path.push_back(vec2{static_cast<float>(center.x + radius * cos(i)),
+								static_cast<float>(center.y + radius * sin(i))});
+		}
+	}
+}
+
+void AI::make_oval_path(float radius_x, float radius_y, const vec2 & center, float start_angle,
+						bool clockwise, float rotation) {
+	if (radius_x <= 0 && radius_y <= 0) {
+		throw std::runtime_error("Radius must be greater than 0");
+	}
+
+	float max_radius = std::max(radius_x, radius_y);
+	// The step size is determined by the radius (step size is in radians)
+	float step = RADIUS_TO_STEP / max_radius;
+	// Force at least MIN_STEP steps (in case of a small radius)
+	if (step > 2 * M_PI / MIN_STEP) {
+		step = 2 * M_PI / MIN_STEP;
+	}
+	// The path node distance is determined by the step size and the radius
+	this->path_node_distance = max_radius * step * PATH_NODE_DISTANCE_FACTOR;
+
+	std::function<vec2(vec2, vec2)> rotate_point = [rotation](vec2 point, vec2 center) {
+		float s = sin(rotation);
+		float c = cos(rotation);
+
+		// Translate point back to origin
+		point.x -= center.x;
+		point.y -= center.y;
+
+		// Rotate point
+		float xnew = point.x * c - point.y * s;
+		float ynew = point.x * s + point.y * c;
+
+		// Translate point back
+		point.x = xnew + center.x;
+		point.y = ynew + center.y;
+
+		return point;
+	};
+
+	if (clockwise) {
+		for (float i = start_angle; i < 2 * M_PI + start_angle; i += step) {
+			vec2 point = {static_cast<float>(center.x + radius_x * cos(i)),
+						  static_cast<float>(center.y + radius_y * sin(i))};
+			path.push_back(rotate_point(point, center));
+		}
+	} else {
+		for (float i = start_angle; i > start_angle - 2 * M_PI; i -= step) {
+			vec2 point = {static_cast<float>(center.x + radius_x * cos(i)),
+						  static_cast<float>(center.y + radius_y * sin(i))};
+			path.push_back(rotate_point(point, center));
+		}
+	}
+}
+
+} // namespace crepe
diff --git a/src/crepe/api/AI.h b/src/crepe/api/AI.h
new file mode 100644
index 0000000..c780a91
--- /dev/null
+++ b/src/crepe/api/AI.h
@@ -0,0 +1,128 @@
+#pragma once
+
+#include "Component.h"
+#include "types.h"
+
+namespace crepe {
+
+/**
+ * \brief The AI component is used to control the movement of an entity using AI.
+ *
+ * The AI component can be used to control the movement of an entity. The AI component can be used
+ * to implement different behaviors such as seeking, fleeing, arriving, and path following.
+ */
+class AI : public Component {
+public:
+	//! The different types of behaviors that can be used
+	enum BehaviorTypeMask {
+		SEEK = 0x00002,
+		FLEE = 0x00004,
+		ARRIVE = 0x00008,
+		PATH_FOLLOW = 0x00010,
+	};
+
+public:
+	/**
+	 * \param id The id of the game object
+	 * \param max_force The maximum force that can be applied to the entity
+	 */
+	AI(game_object_id_t id, float max_force);
+
+	/**
+	 * \brief Check if a behavior is on (aka activated)
+	 *
+	 * \param behavior The behavior to check
+	 * \return true if the behavior is on, false otherwise
+	 */
+	bool on(BehaviorTypeMask behavior) const { return (flags & behavior); }
+	//! Turn on the seek behavior
+	void seek_on() { flags |= SEEK; }
+	//! Turn off the seek behavior
+	void seek_off() { flags &= ~SEEK; }
+	//! Turn on the flee behavior
+	void flee_on() { flags |= FLEE; }
+	//! Turn off the flee behavior
+	void flee_off() { flags &= ~FLEE; }
+	//! Turn on the arrive behavior
+	void arrive_on() { flags |= ARRIVE; }
+	//! Turn off the arrive behavior
+	void arrive_off() { flags &= ~ARRIVE; }
+	//! Turn on the path follow behavior
+	void path_follow_on() { flags |= PATH_FOLLOW; }
+	//! Turn off the path follow behavior
+	void path_follow_off() { flags &= ~PATH_FOLLOW; }
+
+	/**
+	 * \brief Add a path node (for the path following behavior)
+	 *
+	 * \note The path is not relative to the entity's position (it is an absolute path)
+	 *
+	 * \param node The path node to add
+	 */
+	void add_path_node(const vec2 & node) { path.push_back(node); }
+	/**
+	 * \brief Make a circle path (for the path following behavior)
+	 *
+	 * \note The path is not relative to the entity's position (it is an absolute path)
+	 *
+	 * \param radius The radius of the circle (in game units)
+	 * \param center The center of the circle (in game units)
+	 * \param start_angle The start angle of the circle (in radians)
+	 * \param clockwise The direction of the circle
+	 */
+	void make_circle_path(float radius, const vec2 & center = {0, 0}, float start_angle = 0,
+						  bool clockwise = true);
+	/**
+	 * \brief Make an oval path (for the path following behavior)
+	 *
+	 * \note The path is not relative to the entity's position (it is an absolute path)
+	 *
+	 * \param radius_x The x radius of the oval (in game units)
+	 * \param radius_y The y radius of the oval (in game units)
+	 * \param center The center of the oval (in game units)
+	 * \param start_angle The start angle of the oval (in radians)
+	 * \param clockwise The direction of the oval
+	 * \param rotation The rotation of the oval (in radians)
+	 */
+	void make_oval_path(float radius_x, float radius_y, const vec2 & center = {0, 0},
+						float start_angle = 0, bool clockwise = true, float rotation = 0);
+
+public:
+	//! The maximum force that can be applied to the entity (higher values will make the entity adjust faster)
+	float max_force;
+
+	//! The target to seek at
+	vec2 seek_target;
+	//! The target to arrive at
+	vec2 arrive_target;
+	//! The target to flee from
+	vec2 flee_target;
+	//! The distance at which the entity will start to flee from the target
+	float square_flee_panic_distance = 200.0f * 200.0f;
+	//! The deceleration rate for the arrive behavior (higher values will make the entity decelerate faster (less overshoot))
+	float arrive_deceleration = 40.0f;
+	//! The path to follow (for the path following behavior)
+	std::vector<vec2> path;
+	//! The distance from the path node at which the entity will move to the next node (automatically set by make_circle_path())
+	float path_node_distance = 400.0f;
+	//! Looping behavior for the path
+	bool path_loop = true;
+
+private:
+	//! The flags for the behaviors
+	int flags = 0;
+	//! The current path index
+	size_t path_index = 0;
+
+	//! The AISystem is the only class that should access the flags and path_index variables
+	friend class AISystem;
+
+	//! The minimum amount of steps for the path following behavior
+	static constexpr int MIN_STEP = 16;
+	//! The radius to step size ratio for the path following behavior
+	static constexpr float RADIUS_TO_STEP = 400.0f;
+	//! The path node distance factor for the path following behavior
+	static constexpr float PATH_NODE_DISTANCE_FACTOR = 0.75f;
+};
+
+} // namespace crepe
diff --git a/src/crepe/api/AssetManager.cpp b/src/crepe/api/AssetManager.cpp
deleted file mode 100644
index 3925758..0000000
--- a/src/crepe/api/AssetManager.cpp
+++ /dev/null
@@ -1,17 +0,0 @@
-#include "util/Log.h"
-
-#include "AssetManager.h"
-
-using namespace crepe;
-
-AssetManager & AssetManager::get_instance() {
-	static AssetManager instance;
-	return instance;
-}
-
-AssetManager::~AssetManager() {
-	dbg_trace();
-	this->asset_cache.clear();
-}
-
-AssetManager::AssetManager() { dbg_trace(); }
diff --git a/src/crepe/api/AssetManager.h b/src/crepe/api/AssetManager.h
deleted file mode 100644
index 3b1cc4b..0000000
--- a/src/crepe/api/AssetManager.h
+++ /dev/null
@@ -1,62 +0,0 @@
-#pragma once
-
-#include <any>
-#include <memory>
-#include <string>
-#include <unordered_map>
-
-namespace crepe {
-
-/**
- * \brief The AssetManager is responsible for storing and managing assets over multiple scenes.
- *
- * The AssetManager ensures that assets are loaded once and can be accessed across different
- * scenes. It caches assets to avoid reloading them every time a scene is loaded. Assets are
- * retained in memory until the AssetManager is destroyed, at which point the cached assets are
- * cleared.
- */
-class AssetManager {
-
-private:
-	//! A cache that holds all the assets, accessible by their file path, over multiple scenes.
-	std::unordered_map<std::string, std::any> asset_cache;
-
-private:
-	AssetManager();
-	virtual ~AssetManager();
-
-public:
-	AssetManager(const AssetManager &) = delete;
-	AssetManager(AssetManager &&) = delete;
-	AssetManager & operator=(const AssetManager &) = delete;
-	AssetManager & operator=(AssetManager &&) = delete;
-
-	/**
-	 * \brief Retrieves the singleton instance of the AssetManager.
-	 *
-	 * \return A reference to the single instance of the AssetManager.
-	 */
-	static AssetManager & get_instance();
-
-public:
-	/**
-	 * \brief Caches an asset by loading it from the given file path.
-	 *
-	 * \param file_path The path to the asset file to load.
-	 * \param reload If true, the asset will be reloaded from the file, even if it is already
-	 * cached.
-	 * \tparam T The type of asset to cache (e.g., texture, sound, etc.).
-	 *
-	 * \return A shared pointer to the cached asset.
-	 *
-	 * This template function caches the asset at the given file path. If the asset is already
-	 * cached and `reload` is false, the existing cached version will be returned. Otherwise, the
-	 * asset will be reloaded and added to the cache.
-	 */
-	template <typename T>
-	std::shared_ptr<T> cache(const std::string & file_path, bool reload = false);
-};
-
-} // namespace crepe
-
-#include "AssetManager.hpp"
diff --git a/src/crepe/api/AssetManager.hpp b/src/crepe/api/AssetManager.hpp
deleted file mode 100644
index 1c0e978..0000000
--- a/src/crepe/api/AssetManager.hpp
+++ /dev/null
@@ -1,22 +0,0 @@
-#pragma once
-
-#include "AssetManager.h"
-
-namespace crepe {
-
-template <typename asset>
-std::shared_ptr<asset> AssetManager::cache(const std::string & file_path, bool reload) {
-	auto it = asset_cache.find(file_path);
-
-	if (!reload && it != asset_cache.end()) {
-		return std::any_cast<std::shared_ptr<asset>>(it->second);
-	}
-
-	std::shared_ptr<asset> new_asset = std::make_shared<asset>(file_path.c_str());
-
-	asset_cache[file_path] = new_asset;
-
-	return new_asset;
-}
-
-} // namespace crepe
diff --git a/src/crepe/api/AudioSource.cpp b/src/crepe/api/AudioSource.cpp
new file mode 100644
index 0000000..7b05cb1
--- /dev/null
+++ b/src/crepe/api/AudioSource.cpp
@@ -0,0 +1,15 @@
+#include "AudioSource.h"
+
+using namespace crepe;
+using namespace std;
+
+AudioSource::AudioSource(game_object_id_t id, const Asset & src)
+	: Component(id),
+	  source(src) {}
+
+void AudioSource::play(bool looping) {
+	this->loop = looping;
+	this->oneshot_play = true;
+}
+
+void AudioSource::stop() { this->oneshot_stop = true; }
diff --git a/src/crepe/api/AudioSource.h b/src/crepe/api/AudioSource.h
new file mode 100644
index 0000000..b20e490
--- /dev/null
+++ b/src/crepe/api/AudioSource.h
@@ -0,0 +1,74 @@
+#pragma once
+
+#include "../Component.h"
+#include "../facade/SoundHandle.h"
+#include "../types.h"
+
+#include "Asset.h"
+#include "GameObject.h"
+
+namespace crepe {
+
+class AudioSystem;
+
+//! Audio source component
+class AudioSource : public Component {
+	//! AudioSource components are handled by AudioSystem
+	friend class AudioSystem;
+
+protected:
+	/**
+	 * \param source Sound sample to load
+	 */
+	AudioSource(game_object_id_t id, const Asset & source);
+	//! Only ComponentManager creates components
+	friend class ComponentManager;
+
+public:
+	// std::unique_ptr needs to be able to destoy this component
+	virtual ~AudioSource() = default;
+
+public:
+	//! Start this audio source
+	void play(bool looping = false);
+	//! Stop this audio source
+	void stop();
+
+public:
+	//! Play when this component becomes active
+	bool play_on_awake = false;
+	//! Repeat the current audio clip during playback
+	bool loop = false;
+	//! Normalized volume (0.0 - 1.0)
+	float volume = 1.0;
+
+private:
+	//! This audio source's clip
+	const Asset source;
+
+	/**
+	 * \name One-shot state variables
+	 *
+	 * These variables trigger function calls when set to true, and are unconditionally reset on
+	 * every system update.
+	 *
+	 * \{
+	 */
+	//! Play this sample
+	bool oneshot_play = false;
+	//! Stop this sample
+	bool oneshot_stop = false;
+	//! \}
+	/**
+	 * \name State diffing variables
+	 * \{
+	 */
+	typeof(active) last_active = false;
+	typeof(volume) last_volume = volume;
+	typeof(loop) last_loop = loop;
+	//! \}
+	//! This source's voice handle
+	SoundHandle voice{};
+};
+
+} // namespace crepe
diff --git a/src/crepe/api/CMakeLists.txt b/src/crepe/api/CMakeLists.txt
index 593c4e6..118c7ce 100644
--- a/src/crepe/api/CMakeLists.txt
+++ b/src/crepe/api/CMakeLists.txt
@@ -1,5 +1,5 @@
 target_sources(crepe PUBLIC
-	# AudioSource.cpp
+	AudioSource.cpp
 	BehaviorScript.cpp
 	GameObject.cpp
 	Rigidbody.cpp
@@ -7,7 +7,6 @@ target_sources(crepe PUBLIC
 	Transform.cpp
 	Color.cpp
 	Texture.cpp
-	AssetManager.cpp
 	Sprite.cpp
 	Config.cpp
 	Metadata.cpp
@@ -24,10 +23,11 @@ target_sources(crepe PUBLIC
 	Script.cpp
 	Button.cpp
 	UIObject.cpp
+	AI.cpp
 )
 
 target_sources(crepe PUBLIC FILE_SET HEADERS FILES
-	# AudioSource.h
+	AudioSource.h
 	BehaviorScript.h
 	Config.h
 	Script.h
@@ -40,8 +40,6 @@ target_sources(crepe PUBLIC FILE_SET HEADERS FILES
 	Vector2.hpp
 	Color.h
 	Texture.h
-	AssetManager.h
-	AssetManager.hpp
 	Scene.h
 	Metadata.h
 	Camera.h
@@ -58,4 +56,5 @@ target_sources(crepe PUBLIC FILE_SET HEADERS FILES
 	Asset.h
 	Button.h
 	UIObject.h
+	AI.h
 )
diff --git a/src/crepe/api/Config.h b/src/crepe/api/Config.h
index a9745c3..6472270 100644
--- a/src/crepe/api/Config.h
+++ b/src/crepe/api/Config.h
@@ -15,20 +15,10 @@ namespace crepe {
  * modified *before* execution is handed over from the game programmer to the engine (i.e. the
  * main loop is started).
  */
-class Config final {
-public:
+struct Config final {
 	//! Retrieve handle to global Config instance
 	static Config & get_instance();
 
-private:
-	Config() = default;
-	~Config() = default;
-	Config(const Config &) = default;
-	Config(Config &&) = default;
-	Config & operator=(const Config &) = default;
-	Config & operator=(Config &&) = default;
-
-public:
 	//! Logging-related settings
 	struct {
 		/**
@@ -86,6 +76,12 @@ public:
 		 */
 		std::string root_pattern = ".crepe-root";
 	} asset;
+
+	//! Audio system settings
+	struct {
+		//! Max amount of simultanious voices
+		unsigned int voices = 32;
+	} audio;
 };
 
 } // namespace crepe
diff --git a/src/crepe/api/LoopManager.cpp b/src/crepe/api/LoopManager.cpp
index 88243c4..1f0ba72 100644
--- a/src/crepe/api/LoopManager.cpp
+++ b/src/crepe/api/LoopManager.cpp
@@ -1,4 +1,6 @@
+#include "../system/AISystem.h"
 #include "../system/AnimatorSystem.h"
+#include "../system/AudioSystem.h"
 #include "../system/CollisionSystem.h"
 #include "../system/InputSystem.h"
 #include "../system/ParticleSystem.h"
@@ -20,6 +22,8 @@ LoopManager::LoopManager() {
 	this->load_system<RenderSystem>();
 	this->load_system<ScriptSystem>();
 	this->load_system<InputSystem>();
+	this->load_system<AudioSystem>();
+	this->load_system<AISystem>();
 }
 
 void LoopManager::process_input() { this->get_system<InputSystem>().update(); }
@@ -35,8 +39,10 @@ void LoopManager::fixed_update() {
 	EventManager & ev = this->mediator.event_manager;
 	ev.dispatch_events();
 	this->get_system<ScriptSystem>().update();
+	this->get_system<AISystem>().update();
 	this->get_system<PhysicsSystem>().update();
 	this->get_system<CollisionSystem>().update();
+	this->get_system<AudioSystem>().update();
 }
 
 void LoopManager::loop() {
diff --git a/src/crepe/api/LoopManager.h b/src/crepe/api/LoopManager.h
index d8910a0..700afe4 100644
--- a/src/crepe/api/LoopManager.h
+++ b/src/crepe/api/LoopManager.h
@@ -4,6 +4,8 @@
 
 #include "../facade/SDLContext.h"
 #include "../manager/ComponentManager.h"
+#include "../manager/ResourceManager.h"
+#include "../manager/SaveManager.h"
 #include "../manager/SceneManager.h"
 #include "../system/System.h"
 
@@ -95,6 +97,10 @@ private:
 	ComponentManager component_manager{mediator};
 	//! Scene manager instance
 	SceneManager scene_manager{mediator};
+	//! Resource manager instance
+	ResourceManager resource_manager{mediator};
+	//! Save manager instance
+	SaveManager save_manager{mediator};
 
 	//! SDL context \todo no more singletons!
 	SDLContext & sdl_context = SDLContext::get_instance();
diff --git a/src/crepe/api/Script.cpp b/src/crepe/api/Script.cpp
index 4091fd4..753a9e3 100644
--- a/src/crepe/api/Script.cpp
+++ b/src/crepe/api/Script.cpp
@@ -8,8 +8,7 @@ using namespace crepe;
 using namespace std;
 
 Script::~Script() {
-	Mediator & mediator = this->mediator;
-	EventManager & mgr = mediator.event_manager;
+	EventManager & mgr = this->mediator->event_manager;
 	for (auto id : this->listeners) {
 		mgr.unsubscribe(id);
 	}
@@ -21,7 +20,8 @@ void Script::subscribe(const EventHandler<CollisionEvent> & callback) {
 }
 
 void Script::set_next_scene(const string & name) {
-	Mediator & mediator = this->mediator;
-	SceneManager & mgr = mediator.scene_manager;
+	SceneManager & mgr = this->mediator->scene_manager;
 	mgr.set_next_scene(name);
 }
+
+SaveManager & Script::get_save_manager() const { return this->mediator->save_manager; }
diff --git a/src/crepe/api/Script.h b/src/crepe/api/Script.h
index d99ab0e..668e5d1 100644
--- a/src/crepe/api/Script.h
+++ b/src/crepe/api/Script.h
@@ -86,6 +86,25 @@ protected:
 	RefVector<T> get_components() const;
 
 	/**
+	 * \copydoc ComponentManager::get_components_by_id
+	 * \see ComponentManager::get_components_by_id
+	 */
+	template <typename T>
+	RefVector<T> get_components_by_id(game_object_id_t id) const;
+	/**
+	 * \copydoc ComponentManager::get_components_by_name
+	 * \see ComponentManager::get_components_by_name
+	 */
+	template <typename T>
+	RefVector<T> get_components_by_name(const std::string & name) const;
+	/**
+	 * \copydoc ComponentManager::get_components_by_tag
+	 * \see ComponentManager::get_components_by_tag
+	 */
+	template <typename T>
+	RefVector<T> get_components_by_tag(const std::string & tag) const;
+
+	/**
 	 * \brief Log a message using Log::logf
 	 *
 	 * \tparam Args Log::logf parameters
@@ -113,6 +132,9 @@ protected:
 	 */
 	void set_next_scene(const std::string & name);
 
+	//! Retrieve SaveManager reference
+	SaveManager & get_save_manager() const;
+
 	//! \}
 
 private:
diff --git a/src/crepe/api/Script.hpp b/src/crepe/api/Script.hpp
index 45f1ff1..225a51c 100644
--- a/src/crepe/api/Script.hpp
+++ b/src/crepe/api/Script.hpp
@@ -20,10 +20,7 @@ T & Script::get_component() const {
 
 template <typename T>
 RefVector<T> Script::get_components() const {
-	Mediator & mediator = this->mediator;
-	ComponentManager & mgr = mediator.component_manager;
-
-	return mgr.get_components_by_id<T>(this->game_object_id);
+	return this->get_components_by_id<T>(this->game_object_id);
 }
 
 template <typename... Args>
@@ -34,8 +31,7 @@ void Script::logf(Args &&... args) {
 template <typename EventType>
 void Script::subscribe_internal(const EventHandler<EventType> & callback,
 								event_channel_t channel) {
-	Mediator & mediator = this->mediator;
-	EventManager & mgr = mediator.event_manager;
+	EventManager & mgr = this->mediator->event_manager;
 	subscription_t listener = mgr.subscribe<EventType>(
 		[this, callback](const EventType & data) -> bool {
 			bool & active = this->active;
@@ -56,4 +52,26 @@ void Script::subscribe(const EventHandler<EventType> & callback) {
 	this->subscribe_internal(callback, EventManager::CHANNEL_ALL);
 }
 
+template <typename T>
+RefVector<T> Script::get_components_by_id(game_object_id_t id) const {
+	Mediator & mediator = this->mediator;
+	ComponentManager & mgr = mediator.component_manager;
+
+	return mgr.get_components_by_id<T>(id);
+}
+template <typename T>
+RefVector<T> Script::get_components_by_name(const std::string & name) const {
+	Mediator & mediator = this->mediator;
+	ComponentManager & mgr = mediator.component_manager;
+
+	return mgr.get_components_by_name<T>(name);
+}
+template <typename T>
+RefVector<T> Script::get_components_by_tag(const std::string & tag) const {
+	Mediator & mediator = this->mediator;
+	ComponentManager & mgr = mediator.component_manager;
+
+	return mgr.get_components_by_tag<T>(tag);
+}
+
 } // namespace crepe
diff --git a/src/crepe/api/Vector2.h b/src/crepe/api/Vector2.h
index c278c87..bf9d124 100644
--- a/src/crepe/api/Vector2.h
+++ b/src/crepe/api/Vector2.h
@@ -66,6 +66,30 @@ struct Vector2 {
 
 	//! Checks if this vector is not equal to another vector.
 	bool operator!=(const Vector2<T> & other) const;
+
+	//! Truncates the vector to a maximum length.
+	void truncate(T max);
+
+	//! Normalizes the vector (resulting in vector with a length of 1).
+	void normalize();
+
+	//! Returns the length of the vector.
+	T length() const;
+
+	//! Returns the squared length of the vector.
+	T length_squared() const;
+
+	//! Returns the dot product (inwendig product) of this vector and another vector.
+	T dot(const Vector2<T> & other) const;
+
+	//! Returns the distance between this vector and another vector.
+	T distance(const Vector2<T> & other) const;
+
+	//! Returns the squared distance between this vector and another vector.
+	T distance_squared(const Vector2<T> & other) const;
+
+	//! Returns the perpendicular vector to this vector.
+	Vector2 perpendicular() const;
 };
 
 } // namespace crepe
diff --git a/src/crepe/api/Vector2.hpp b/src/crepe/api/Vector2.hpp
index cad15f8..ff53cb0 100644
--- a/src/crepe/api/Vector2.hpp
+++ b/src/crepe/api/Vector2.hpp
@@ -1,5 +1,7 @@
 #pragma once
 
+#include <cmath>
+
 #include "Vector2.h"
 
 namespace crepe {
@@ -115,4 +117,50 @@ bool Vector2<T>::operator!=(const Vector2<T> & other) const {
 	return !(*this == other);
 }
 
+template <class T>
+void Vector2<T>::truncate(T max) {
+	if (length() > max) {
+		normalize();
+		*this *= max;
+	}
+}
+
+template <class T>
+void Vector2<T>::normalize() {
+	T len = length();
+	if (len > 0) {
+		*this /= len;
+	}
+}
+
+template <class T>
+T Vector2<T>::length() const {
+	return std::sqrt(x * x + y * y);
+}
+
+template <class T>
+T Vector2<T>::length_squared() const {
+	return x * x + y * y;
+}
+
+template <class T>
+T Vector2<T>::dot(const Vector2<T> & other) const {
+	return x * other.x + y * other.y;
+}
+
+template <class T>
+T Vector2<T>::distance(const Vector2<T> & other) const {
+	return (*this - other).length();
+}
+
+template <class T>
+T Vector2<T>::distance_squared(const Vector2<T> & other) const {
+	return (*this - other).length_squared();
+}
+
+template <class T>
+Vector2<T> Vector2<T>::perpendicular() const {
+	return {-y, x};
+}
+
 } // namespace crepe