23 files changed, 785 insertions, 141 deletions

diff --git a/src/crepe/Particle.cpp b/src/crepe/Particle.cpp
index 4810e80..582edf4 100644
--- a/src/crepe/Particle.cpp
+++ b/src/crepe/Particle.cpp
@@ -2,19 +2,32 @@
 
 using namespace crepe;
 
-Particle::Particle() { this->active = false; }
-
-void Particle::reset(float lifespan, Position position, Position velocity) {
+void Particle::reset(uint32_t lifespan, const Vector2 & position,
+					 const Vector2 & velocity, double angle) {
+	// Initialize the particle state
 	this->time_in_life = 0;
 	this->lifespan = lifespan;
 	this->position = position;
 	this->velocity = velocity;
+	this->angle = angle;
 	this->active = true;
+	// Reset force accumulation
+	this->force_over_time = {0, 0};
+}
+
+void Particle::update() {
+	// Deactivate particle if it has exceeded its lifespan
+	if (++time_in_life >= lifespan) {
+		this->active = false;
+		return;
+	}
+
+	// Update velocity based on accumulated force and update position
+	this->velocity += force_over_time;
+	this->position += velocity;
 }
 
-void Particle::update(float deltaTime) {
-	time_in_life += deltaTime;
-	position.x += velocity.x * deltaTime;
-	position.y += velocity.y * deltaTime;
-	if (time_in_life >= lifespan) this->active = false;
+void Particle::stop_movement() {
+	// Reset velocity to halt movement
+	this->velocity = {0, 0};
 }
diff --git a/src/crepe/Particle.h b/src/crepe/Particle.h
index 21e691d..3eaebc3 100644
--- a/src/crepe/Particle.h
+++ b/src/crepe/Particle.h
@@ -1,22 +1,64 @@
 #pragma once
 
-#include "Position.h"
+#include <cstdint>
+
+#include "api/Vector2.h"
 
 namespace crepe {
 
+/**
+ * \brief Represents a particle in the particle emitter.
+ *
+ * This class stores information about a single particle, including its position,
+ * velocity, lifespan, and other properties. Particles can be updated over time
+ * to simulate movement and can also be reset or stopped.
+ */
 class Particle {
+	// TODO: add friend particleSsytem and rendersystem. Unit test will fail.
+
 public:
-	Position position;
-	// FIXME: `Position` is an awkward name for a 2D vector. See FIXME comment in
-	// api/Transform.h for fix proposal.
-	Position velocity;
-	float lifespan;
-	bool active;
+	//! Position of the particle in 2D space.
+	Vector2 position;
+	//! Velocity vector indicating the speed and direction of the particle.
+	Vector2 velocity;
+	//! Accumulated force affecting the particle over time.
+	Vector2 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.
+	bool active = false;
+	//! The time the particle has been alive, in milliseconds.
+	uint32_t time_in_life = 0;
+	//! The angle at which the particle is oriented or moving.
+	double angle = 0;
 
-	Particle();
-	void reset(float lifespan, Position position, Position velocity);
-	void update(float deltaTime);
-	float time_in_life;
+	/**
+	 * \brief Resets the particle with new properties.
+	 *
+	 * This method initializes the particle with a specific lifespan, position,
+	 * velocity, and angle, marking it as active and resetting its life counter.
+	 *
+	 * \param lifespan  The lifespan of the particle in amount of updates.
+	 * \param position  The starting position of the particle.
+	 * \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);
+	/**
+	 * \brief Updates the particle's state.
+	 *
+	 * Advances the particle's position based on its velocity and applies accumulated forces. 
+	 * Deactivates the particle if its lifespan has expired.
+	 */
+	void update();
+	/**
+	 * \brief Stops the particle's movement.
+	 *
+	 * Sets the particle's velocity to zero, effectively halting any further
+	 * movement.
+	 */
+	void stop_movement();
 };
 
 } // namespace crepe
diff --git a/src/crepe/ValueBroker.hpp b/src/crepe/ValueBroker.hpp
index 927142f..5c3bed9 100644
--- a/src/crepe/ValueBroker.hpp
+++ b/src/crepe/ValueBroker.hpp
@@ -6,7 +6,8 @@ namespace crepe {
 
 template <typename T>
 ValueBroker<T>::ValueBroker(const setter_t & setter, const getter_t & getter)
-	: setter(setter), getter(getter) {}
+	: setter(setter),
+	  getter(getter) {}
 
 template <typename T>
 const T & ValueBroker<T>::get() {
diff --git a/src/crepe/api/Animator.cpp b/src/crepe/api/Animator.cpp
index 8b396af..58fee2a 100644
--- a/src/crepe/api/Animator.cpp
+++ b/src/crepe/api/Animator.cpp
@@ -10,7 +10,10 @@
 using namespace crepe;
 
 Animator::Animator(uint32_t id, Sprite & ss, int row, int col, int col_animator)
-	: Component(id), spritesheet(ss), row(row), col(col) {
+	: Component(id),
+	  spritesheet(ss),
+	  row(row),
+	  col(col) {
 	dbg_trace();
 
 	animator_rect = spritesheet.sprite_rect;
diff --git a/src/crepe/api/AssetManager.h b/src/crepe/api/AssetManager.h
index fefbed9..86a9902 100644
--- a/src/crepe/api/AssetManager.h
+++ b/src/crepe/api/AssetManager.h
@@ -7,9 +7,19 @@
 
 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:
@@ -22,12 +32,32 @@ public:
 	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:
-	template <typename asset>
-	std::shared_ptr<asset> cache(const std::string & file_path,
-								 bool reload = false);
+	/**
+	 * \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
diff --git a/src/crepe/api/CMakeLists.txt b/src/crepe/api/CMakeLists.txt
index 6915074..de1b4b3 100644
--- a/src/crepe/api/CMakeLists.txt
+++ b/src/crepe/api/CMakeLists.txt
@@ -18,8 +18,13 @@ target_sources(crepe PUBLIC
 	Vector2.cpp
 	Camera.cpp
 	Animator.cpp
+<<<<<<< HEAD
 	BoxCollider.cpp
 	CircleCollider.cpp
+=======
+	LoopManager.cpp
+	LoopTimer.cpp
+>>>>>>> be1e97bc7a494963ab1567492fafcda99e36f683
 )
 
 target_sources(crepe PUBLIC FILE_SET HEADERS FILES
@@ -44,6 +49,11 @@ target_sources(crepe PUBLIC FILE_SET HEADERS FILES
 	SceneManager.hpp
 	Camera.h
 	Animator.h
+<<<<<<< HEAD
 	BoxCollider.h
 	CircleCollider.h
+=======
+	LoopManager.h
+	LoopTimer.h
+>>>>>>> be1e97bc7a494963ab1567492fafcda99e36f683
 )
diff --git a/src/crepe/api/Camera.cpp b/src/crepe/api/Camera.cpp
index 820a6a8..6355a03 100644
--- a/src/crepe/api/Camera.cpp
+++ b/src/crepe/api/Camera.cpp
@@ -10,7 +10,8 @@
 using namespace crepe;
 
 Camera::Camera(uint32_t id, const Color & bg_color)
-	: Component(id), bg_color(bg_color) {
+	: Component(id),
+	  bg_color(bg_color) {
 	dbg_trace();
 }
 
diff --git a/src/crepe/api/CircleCollider.h b/src/crepe/api/CircleCollider.h
index 29a9c1e..e4f0452 100644
--- a/src/crepe/api/CircleCollider.h
+++ b/src/crepe/api/CircleCollider.h
@@ -8,8 +8,15 @@ namespace crepe {
 
 class CircleCollider : public Collider {
 public:
+<<<<<<< HEAD
 	CircleCollider(game_object_id_t game_object_id,Vector2 offset, int radius);
 	double radius;
+=======
+	CircleCollider(game_object_id_t game_object_id, int radius)
+		: Collider(game_object_id),
+		  radius(radius) {}
+	int radius;
+>>>>>>> be1e97bc7a494963ab1567492fafcda99e36f683
 };
 
 } // namespace crepe
diff --git a/src/crepe/api/LoopManager.cpp b/src/crepe/api/LoopManager.cpp
new file mode 100644
index 0000000..2e9823f
--- /dev/null
+++ b/src/crepe/api/LoopManager.cpp
@@ -0,0 +1,55 @@
+
+#include "../facade/SDLContext.h"
+#include "../system/RenderSystem.h"
+#include "../system/ScriptSystem.h"
+
+#include "LoopManager.h"
+#include "LoopTimer.h"
+
+using namespace crepe;
+
+LoopManager::LoopManager() {}
+void LoopManager::process_input() {
+	SDLContext::get_instance().handle_events(this->game_running);
+}
+void LoopManager::start() {
+	this->setup();
+	this->loop();
+}
+void LoopManager::set_running(bool running) { this->game_running = running; }
+
+void LoopManager::fixed_update() {}
+
+void LoopManager::loop() {
+	LoopTimer & timer = LoopTimer::get_instance();
+	timer.start();
+
+	while (game_running) {
+		timer.update();
+
+		while (timer.get_lag() >= timer.get_fixed_delta_time()) {
+			this->process_input();
+			this->fixed_update();
+			timer.advance_fixed_update();
+		}
+
+		this->update();
+		this->render();
+
+		timer.enforce_frame_rate();
+	}
+}
+
+void LoopManager::setup() {
+	this->game_running = true;
+	LoopTimer::get_instance().start();
+	LoopTimer::get_instance().set_fps(60);
+}
+
+void LoopManager::render() {
+	if (this->game_running) {
+		RenderSystem::get_instance().update();
+	}
+}
+
+void LoopManager::update() { LoopTimer & timer = LoopTimer::get_instance(); }
diff --git a/src/crepe/api/LoopManager.h b/src/crepe/api/LoopManager.h
new file mode 100644
index 0000000..2f03193
--- /dev/null
+++ b/src/crepe/api/LoopManager.h
@@ -0,0 +1,79 @@
+#pragma once
+
+#include <memory>
+
+class RenderSystem;
+class SDLContext;
+class LoopTimer;
+class ScriptSystem;
+class SoundSystem;
+class ParticleSystem;
+class PhysicsSystem;
+class AnimatorSystem;
+class CollisionSystem;
+namespace crepe {
+
+class LoopManager {
+public:
+	void start();
+	LoopManager();
+
+private:
+	/**
+	 * \brief Setup function for one-time initialization.
+	 *
+	 * This function initializes necessary components for the game.
+	 */
+	void setup();
+	/**
+	 * \brief Main game loop function.
+	 *
+	 * This function runs the main loop, handling game updates and rendering.
+	 */
+	void loop();
+
+	/**
+	 * \brief Function for handling input-related system calls.
+	 *
+	 * Processes user inputs from keyboard and mouse.
+	 */
+	void process_input();
+
+	/**
+	 * \brief Per-frame update.
+	 *
+	 * Updates the game state based on the elapsed time since the last frame.
+	 */
+	void update();
+
+	/**
+	 * \brief Late update which is called after update().
+	 *
+	 * This function can be used for final adjustments before rendering.
+	 */
+	void late_update();
+
+	/**
+	 * \brief Fixed update executed at a fixed rate.
+	 *
+	 * This function updates physics and game logic based on LoopTimer's fixed_delta_time.
+	 */
+	void fixed_update();
+	/**
+	 * \brief Set game running variable
+	 *
+	 * \param running running (false = game shutdown, true = game running)
+	 */
+	void set_running(bool running);
+	/**
+	 * \brief Function for executing render-related systems.
+	 *
+	 * Renders the current state of the game to the screen.
+	 */
+	void render();
+
+	bool game_running = false;
+	//#TODO add system instances
+};
+
+} // namespace crepe
diff --git a/src/crepe/api/LoopTimer.cpp b/src/crepe/api/LoopTimer.cpp
new file mode 100644
index 0000000..8f09e41
--- /dev/null
+++ b/src/crepe/api/LoopTimer.cpp
@@ -0,0 +1,86 @@
+#include <chrono>
+
+#include "../facade/SDLContext.h"
+#include "../util/log.h"
+
+#include "LoopTimer.h"
+
+using namespace crepe;
+
+LoopTimer::LoopTimer() { dbg_trace(); }
+
+LoopTimer & LoopTimer::get_instance() {
+	static LoopTimer instance;
+	return instance;
+}
+
+void LoopTimer::start() {
+	this->last_frame_time = std::chrono::steady_clock::now();
+	this->elapsed_time = std::chrono::milliseconds(0);
+	this->elapsed_fixed_time = std::chrono::milliseconds(0);
+	this->delta_time = std::chrono::milliseconds(0);
+}
+
+void LoopTimer::update() {
+	auto current_frame_time = std::chrono::steady_clock::now();
+	// Convert to duration in seconds for delta time
+	this->delta_time
+		= std::chrono::duration_cast<std::chrono::duration<double>>(
+			current_frame_time - last_frame_time);
+
+	if (this->delta_time > this->maximum_delta_time) {
+		this->delta_time = this->maximum_delta_time;
+	}
+
+	this->delta_time *= this->game_scale;
+	this->elapsed_time += this->delta_time;
+	this->last_frame_time = current_frame_time;
+}
+
+double LoopTimer::get_delta_time() const { return this->delta_time.count(); }
+
+double LoopTimer::get_current_time() const {
+	return this->elapsed_time.count();
+}
+
+void LoopTimer::advance_fixed_update() {
+	this->elapsed_fixed_time += this->fixed_delta_time;
+}
+
+double LoopTimer::get_fixed_delta_time() const {
+	return this->fixed_delta_time.count();
+}
+
+void LoopTimer::set_fps(int fps) {
+	this->fps = fps;
+	// target time per frame in seconds
+	this->frame_target_time = std::chrono::seconds(1) / fps;
+}
+
+int LoopTimer::get_fps() const { return this->fps; }
+
+void LoopTimer::set_game_scale(double value) { this->game_scale = value; }
+
+double LoopTimer::get_game_scale() const { return this->game_scale; }
+void LoopTimer::enforce_frame_rate() {
+	std::chrono::steady_clock::time_point current_frame_time
+		= std::chrono::steady_clock::now();
+	std::chrono::milliseconds frame_duration
+		= std::chrono::duration_cast<std::chrono::milliseconds>(
+			current_frame_time - this->last_frame_time);
+
+	if (frame_duration < this->frame_target_time) {
+		std::chrono::milliseconds delay_time
+			= std::chrono::duration_cast<std::chrono::milliseconds>(
+				this->frame_target_time - frame_duration);
+		if (delay_time.count() > 0) {
+			SDLContext::get_instance().delay(delay_time.count());
+		}
+	}
+
+	this->last_frame_time = current_frame_time;
+}
+
+double LoopTimer::get_lag() const {
+	return (this->elapsed_time - this->elapsed_fixed_time).count();
+}
diff --git a/src/crepe/api/LoopTimer.h b/src/crepe/api/LoopTimer.h
new file mode 100644
index 0000000..85687be
--- /dev/null
+++ b/src/crepe/api/LoopTimer.h
@@ -0,0 +1,147 @@
+#pragma once
+
+#include <chrono>
+#include <cstdint>
+
+namespace crepe {
+
+class LoopTimer {
+public:
+	/**
+     * \brief Get the singleton instance of LoopTimer.
+     *
+     * \return A reference to the LoopTimer instance.
+     */
+	static LoopTimer & get_instance();
+
+	/**
+     * \brief Get the current delta time for the current frame.
+     *
+     * \return Delta time in seconds since the last frame.
+     */
+	double get_delta_time() const;
+
+	/**
+     * \brief Get the current game time.
+     *
+     * \note The current game time may vary from real-world elapsed time.
+     * It is the cumulative sum of each frame's delta time.
+     *
+     * \return Elapsed game time in seconds.
+     */
+	double get_current_time() const;
+
+	/**
+     * \brief Set the target frames per second (FPS).
+     *
+     * \param fps The desired frames rendered per second.
+     */
+	void set_fps(int fps);
+
+	/**
+     * \brief Get the current frames per second (FPS).
+     *
+     * \return Current FPS.
+     */
+	int get_fps() const;
+
+	/**
+     * \brief Get the current game scale.
+     *
+     * \return The current game scale, where 0 = paused, 1 = normal speed, and values > 1 speed up the game.
+     */
+	double get_game_scale() const;
+
+	/**
+     * \brief Set the game scale.
+     *
+     * \param game_scale The desired game scale (0 = pause, 1 = normal speed, > 1 = speed up).
+     */
+	void set_game_scale(double game_scale);
+
+private:
+	friend class LoopManager;
+
+	/**
+     * \brief Start the loop timer.
+     *
+     * Initializes the timer to begin tracking frame times.
+     */
+	void start();
+
+	/**
+     * \brief Enforce the frame rate limit.
+     *
+     * Ensures that the game loop does not exceed the target FPS by delaying
+     * frame updates as necessary.
+     */
+	void enforce_frame_rate();
+
+	/**
+     * \brief Get the fixed delta time for consistent updates.
+     *
+     * Fixed delta time is used for operations that require uniform time steps,
+     * such as physics calculations.
+     *
+     * \return Fixed delta time in seconds.
+     */
+	double get_fixed_delta_time() const;
+
+	/**
+     * \brief Get the accumulated lag in the game loop.
+     *
+     * Lag represents the difference between the target frame time and the
+     * actual frame time, useful for managing fixed update intervals.
+     *
+     * \return Accumulated lag in seconds.
+     */
+	double get_lag() const;
+
+	/**
+     * \brief Construct a new LoopTimer object.
+     *
+     * Private constructor for singleton pattern to restrict instantiation
+     * outside the class.
+     */
+	LoopTimer();
+
+	/**
+     * \brief Update the timer to the current frame.
+     *
+     * Calculates and updates the delta time for the current frame and adds it to
+     * the cumulative game time.
+     */
+	void update();
+
+	/**
+     * \brief Advance the game loop by a fixed update interval.
+     *
+     * This method progresses the game state by a consistent, fixed time step,
+     * allowing for stable updates independent of frame rate fluctuations.
+     */
+	void advance_fixed_update();
+
+private:
+	//! Current frames per second
+	int fps = 50;
+	//! Current game scale
+	double game_scale = 1;
+	//! Maximum delta time in seconds to avoid large jumps
+	std::chrono::duration<double> maximum_delta_time{0.25};
+	//! Delta time for the current frame in seconds
+	std::chrono::duration<double> delta_time{0.0};
+	//! Target time per frame in seconds
+	std::chrono::duration<double> frame_target_time
+		= std::chrono::seconds(1) / fps;
+	//! Fixed delta time for fixed updates in seconds
+	std::chrono::duration<double> fixed_delta_time
+		= std::chrono::seconds(1) / 50;
+	//! Total elapsed game time in seconds
+	std::chrono::duration<double> elapsed_time{0.0};
+	//! Total elapsed time for fixed updates in seconds
+	std::chrono::duration<double> elapsed_fixed_time{0.0};
+	//! Time of the last frame
+	std::chrono::steady_clock::time_point last_frame_time;
+};
+
+} // namespace crepe
diff --git a/src/crepe/api/Metadata.cpp b/src/crepe/api/Metadata.cpp
index 76f11d7..d421de5 100644
--- a/src/crepe/api/Metadata.cpp
+++ b/src/crepe/api/Metadata.cpp
@@ -4,4 +4,6 @@ using namespace crepe;
 using namespace std;
 
 Metadata::Metadata(game_object_id_t id, const string & name, const string & tag)
-	: Component(id), name(name), tag(tag) {}
+	: Component(id),
+	  name(name),
+	  tag(tag) {}
diff --git a/src/crepe/api/ParticleEmitter.cpp b/src/crepe/api/ParticleEmitter.cpp
index 3b2e2f2..35f960d 100644
--- a/src/crepe/api/ParticleEmitter.cpp
+++ b/src/crepe/api/ParticleEmitter.cpp
@@ -1,36 +1,12 @@
-#include <ctime>
-#include <iostream>
-
-#include "Particle.h"
 #include "ParticleEmitter.h"
 
 using namespace crepe;
 
-ParticleEmitter::ParticleEmitter(game_object_id_t id, uint32_t max_particles,
-								 uint32_t emission_rate, uint32_t speed,
-								 uint32_t speed_offset, uint32_t angle,
-								 uint32_t angleOffset, float begin_lifespan,
-								 float end_lifespan)
-	: Component(id), max_particles(max_particles), emission_rate(emission_rate),
-	  speed(speed), speed_offset(speed_offset), position{0, 0},
-	  begin_lifespan(begin_lifespan), end_lifespan(end_lifespan) {
-	std::srand(
-		static_cast<uint32_t>(std::time(nullptr))); // initialize random seed
-	std::cout << "Create emitter" << std::endl;
-	// FIXME: Why do these expressions start with `360 +`, only to be `% 360`'d
-	// right after? This does not make any sense to me.
-	min_angle = (360 + angle - (angleOffset % 360)) % 360;
-	max_angle = (360 + angle + (angleOffset % 360)) % 360;
-	position.x = 400; // FIXME: what are these magic values?
-	position.y = 400;
-	for (size_t i = 0; i < max_particles; i++) {
-		this->particles.emplace_back();
-	}
-}
-
-ParticleEmitter::~ParticleEmitter() {
-	std::vector<Particle>::iterator it = this->particles.begin();
-	while (it != this->particles.end()) {
-		it = this->particles.erase(it);
+ParticleEmitter::ParticleEmitter(game_object_id_t game_object_id,
+								 const Data & data)
+	: Component(game_object_id),
+	  data(data) {
+	for (size_t i = 0; i < this->data.max_particles; i++) {
+		this->data.particles.emplace_back();
 	}
 }
diff --git a/src/crepe/api/ParticleEmitter.h b/src/crepe/api/ParticleEmitter.h
index 5939723..a9e872f 100644
--- a/src/crepe/api/ParticleEmitter.h
+++ b/src/crepe/api/ParticleEmitter.h
@@ -1,42 +1,85 @@
 #pragma once
 
-#include <cstdint>
 #include <vector>
 
 #include "Component.h"
 #include "Particle.h"
+#include "Vector2.h"
 
 namespace crepe {
 
+class Sprite;
+
+/**
+ * \brief Data holder for particle emission parameters.
+ *
+ * The ParticleEmitter class stores configuration data for particle properties,
+ * defining the characteristics and boundaries of particle emissions.
+ */
 class ParticleEmitter : public Component {
 public:
-	ParticleEmitter(game_object_id_t id, uint32_t max_particles,
-					uint32_t emission_rate, uint32_t speed,
-					uint32_t speed_offset, uint32_t angle, uint32_t angleOffset,
-					float begin_lifespan, float end_lifespan);
-	~ParticleEmitter();
-
-	//! position of the emitter
-	Position position;
-	//! maximum number of particles
-	uint32_t max_particles;
-	//! rate of particle emission
-	uint32_t emission_rate;
-	//! base speed of the particles
-	uint32_t speed;
-	//! offset for random speed variation
-	uint32_t speed_offset;
-	//! min angle of particle emission
-	uint32_t min_angle;
-	//! max angle of particle emission
-	uint32_t max_angle;
-	//! begin Lifespan of particle (only visual)
-	float begin_lifespan;
-	//! begin Lifespan of particle
-	float end_lifespan;
-
-	//! collection of particles
-	std::vector<Particle> particles;
+	/**
+	 * \brief Defines the boundary within which particles are constrained.
+	 *
+	 * This structure specifies the boundary's size and offset, as well as the
+	 * behavior of particles upon reaching the boundary limits.
+	 */
+	struct Boundary {
+		//! boundary width (midpoint is emitter location)
+		double width = 0.0;
+		//! boundary height (midpoint is emitter location)
+		double height = 0.0;
+		//! boundary offset from particle emitter location
+		Vector2 offset;
+		//! reset on exit or stop velocity and set max postion
+		bool reset_on_exit = false;
+	};
+
+	/**
+	 * \brief Holds parameters that control particle emission.
+	 *
+	 * Contains settings for the emitter’s position, particle speed, angle, lifespan,
+	 * boundary, and the sprite used for rendering particles.
+	 */
+	struct Data {
+		//! position of the emitter
+		Vector2 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)
+		double emission_rate = 0;
+		//! min speed of the particles
+		double min_speed = 0;
+		//! min speed of the particles
+		double max_speed = 0;
+		//! min angle of particle emission
+		double min_angle = 0;
+		//! max angle of particle emission
+		double max_angle = 0;
+		//! begin Lifespan of particle (only visual)
+		double begin_lifespan = 0.0;
+		//! end Lifespan of particle
+		double end_lifespan = 0.0;
+		//! force over time (physics)
+		Vector2 force_over_time;
+		//! particle boundary
+		Boundary boundary;
+		//! collection of particles
+		std::vector<Particle> particles;
+		//! sprite reference
+		const Sprite & sprite;
+	};
+
+public:
+	/**
+	 * \param game_object_id  Identifier for the game object using this emitter.
+	 * \param data            Configuration data defining particle properties.
+	 */
+	ParticleEmitter(game_object_id_t game_object_id, const Data & data);
+
+public:
+	//! Configuration data for particle emission settings.
+	Data data;
 };
 
 } // namespace crepe
diff --git a/src/crepe/api/Rigidbody.cpp b/src/crepe/api/Rigidbody.cpp
index cbf1325..3bf1c5b 100644
--- a/src/crepe/api/Rigidbody.cpp
+++ b/src/crepe/api/Rigidbody.cpp
@@ -3,7 +3,8 @@
 using namespace crepe;
 
 crepe::Rigidbody::Rigidbody(uint32_t game_object_id, const Data & data)
-	: Component(game_object_id), data(data) {}
+	: Component(game_object_id),
+	  data(data) {}
 
 void crepe::Rigidbody::add_force_linear(const Vector2 & force) {
 	this->data.linear_velocity += force;
diff --git a/src/crepe/api/Sprite.cpp b/src/crepe/api/Sprite.cpp
index f9cd761..6f0433f 100644
--- a/src/crepe/api/Sprite.cpp
+++ b/src/crepe/api/Sprite.cpp
@@ -12,7 +12,10 @@ using namespace crepe;
 
 Sprite::Sprite(game_object_id_t id, const shared_ptr<Texture> image,
 			   const Color & color, const FlipSettings & flip)
-	: Component(id), color(color), flip(flip), sprite_image(image) {
+	: Component(id),
+	  color(color),
+	  flip(flip),
+	  sprite_image(image) {
 	dbg_trace();
 
 	this->sprite_rect.w = sprite_image->get_width();
diff --git a/src/crepe/api/Transform.cpp b/src/crepe/api/Transform.cpp
index a244bc5..e401120 100644
--- a/src/crepe/api/Transform.cpp
+++ b/src/crepe/api/Transform.cpp
@@ -6,6 +6,9 @@ using namespace crepe;
 
 Transform::Transform(game_object_id_t id, const Vector2 & point,
 					 double rotation, double scale)
-	: Component(id), position(point), rotation(rotation), scale(scale) {
+	: Component(id),
+	  position(point),
+	  rotation(rotation),
+	  scale(scale) {
 	dbg_trace();
 }
diff --git a/src/crepe/facade/SDLContext.cpp b/src/crepe/facade/SDLContext.cpp
index c4c96e2..236bf8c 100644
--- a/src/crepe/facade/SDLContext.cpp
+++ b/src/crepe/facade/SDLContext.cpp
@@ -159,7 +159,7 @@ SDLContext::texture_from_path(const std::string & path) {
 
 	SDL_Surface * tmp = IMG_Load(path.c_str());
 	if (tmp == nullptr) {
-		throw Exception("surface cannot be load from %s", path.c_str());
+		tmp = IMG_Load("../asset/texture/ERROR.png");
 	}
 
 	std::unique_ptr<SDL_Surface, std::function<void(SDL_Surface *)>>
@@ -191,3 +191,4 @@ int SDLContext::get_height(const Texture & ctx) const {
 	SDL_QueryTexture(ctx.texture.get(), NULL, NULL, NULL, &h);
 	return h;
 }
+void SDLContext::delay(int ms) const { SDL_Delay(ms); }
diff --git a/src/crepe/facade/SDLContext.h b/src/crepe/facade/SDLContext.h
index e358c21..536dec5 100644
--- a/src/crepe/facade/SDLContext.h
+++ b/src/crepe/facade/SDLContext.h
@@ -58,12 +58,23 @@ private:
 private:
 	//! Will only use get_ticks
 	friend class AnimatorSystem;
-
+	//! Will only use delay
+	friend class LoopTimer;
 	/**
 	 * \brief Gets the current SDL ticks since the program started.
 	 * \return Current ticks in milliseconds as a constant uint64_t.
 	 */
 	uint64_t get_ticks() const;
+	/**
+	 * \brief Pauses the execution for a specified duration.
+	 *
+	 * This function uses SDL's delay function to halt the program execution
+	 * for a given number of milliseconds, allowing for frame rate control
+	 * or other timing-related functionality.
+	 *
+	 * \param ms Duration of the delay in milliseconds.
+	 */
+	void delay(int ms) const;
 
 private:
 	/**
diff --git a/src/crepe/system/ParticleSystem.cpp b/src/crepe/system/ParticleSystem.cpp
index 397b586..e7a3bec 100644
--- a/src/crepe/system/ParticleSystem.cpp
+++ b/src/crepe/system/ParticleSystem.cpp
@@ -1,62 +1,141 @@
 #include <cmath>
+#include <cstdlib>
 #include <ctime>
 
-#include "../ComponentManager.h"
-#include "../api/ParticleEmitter.h"
+#include "api/ParticleEmitter.h"
+#include "api/Transform.h"
+#include "api/Vector2.h"
 
+#include "ComponentManager.h"
 #include "ParticleSystem.h"
 
 using namespace crepe;
 
-ParticleSystem::ParticleSystem() : elapsed_time(0.0f) {}
-
 void ParticleSystem::update() {
+	// Get all emitters
 	ComponentManager & mgr = ComponentManager::get_instance();
 	std::vector<std::reference_wrapper<ParticleEmitter>> emitters
 		= mgr.get_components_by_type<ParticleEmitter>();
-	float delta_time = 0.10;
+
 	for (ParticleEmitter & emitter : emitters) {
-		float update_amount = 1 / static_cast<float>(emitter.emission_rate);
-		for (float i = 0; i < delta_time; i += update_amount) {
-			emit_particle(emitter);
+		// Get transform linked to emitter
+		const Transform & transform
+			= mgr.get_components_by_id<Transform>(emitter.game_object_id)
+				  .front()
+				  .get();
+
+		// Emit particles based on emission_rate
+		int updates
+			= calculate_update(this->update_count, emitter.data.emission_rate);
+		for (size_t i = 0; i < updates; i++) {
+			emit_particle(emitter, transform);
 		}
-		for (size_t j = 0; j < emitter.particles.size(); j++) {
-			if (emitter.particles[j].active) {
-				emitter.particles[j].update(delta_time);
+
+		// Update all particles
+		for (Particle & particle : emitter.data.particles) {
+			if (particle.active) {
+				particle.update();
 			}
 		}
+
+		// Check if within boundary
+		check_bounds(emitter, transform);
 	}
+
+	this->update_count = (this->update_count + 1) % this->MAX_UPDATE_COUNT;
 }
 
-void ParticleSystem::emit_particle(ParticleEmitter & emitter) {
-	Position initial_position = {emitter.position.x, emitter.position.y};
-	float random_angle = 0.0f;
-	if (emitter.max_angle < emitter.min_angle) {
-		random_angle = ((emitter.min_angle
-						 + (std::rand()
-							% (static_cast<uint32_t>(emitter.max_angle + 360
-													 - emitter.min_angle + 1))))
-						% 360);
-	} else {
-		random_angle = emitter.min_angle
-					   + (std::rand()
-						  % (static_cast<uint32_t>(emitter.max_angle
-												   - emitter.min_angle + 1)));
-	}
-	float angle_in_radians = random_angle * (M_PI / 180.0f);
-	float random_speed_offset = (static_cast<float>(std::rand()) / RAND_MAX)
-									* (2 * emitter.speed_offset)
-								- emitter.speed_offset;
-	float velocity_x
-		= (emitter.speed + random_speed_offset) * std::cos(angle_in_radians);
-	float velocity_y
-		= (emitter.speed + random_speed_offset) * std::sin(angle_in_radians);
-	Position initial_velocity = {velocity_x, velocity_y};
-	for (size_t i = 0; i < emitter.particles.size(); i++) {
-		if (!emitter.particles[i].active) {
-			emitter.particles[i].reset(emitter.end_lifespan, initial_position,
-									   initial_velocity);
+void ParticleSystem::emit_particle(ParticleEmitter & emitter,
+								   const Transform & transform) {
+	constexpr double 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);
+
+	double random_speed
+		= generate_random_speed(emitter.data.min_speed, emitter.data.max_speed);
+	double angle_radians = random_angle * DEG_TO_RAD;
+
+	Vector2 velocity = {random_speed * std::cos(angle_radians),
+						random_speed * std::sin(angle_radians)};
+
+	for (Particle & particle : emitter.data.particles) {
+		if (!particle.active) {
+			particle.reset(emitter.data.end_lifespan, initial_position,
+						   velocity, random_angle);
 			break;
 		}
 	}
 }
+
+int ParticleSystem::calculate_update(int count, double emission) const {
+	double integer_part = std::floor(emission);
+	double fractional_part = emission - integer_part;
+
+	if (fractional_part > 0) {
+		int denominator = static_cast<int>(1.0 / fractional_part);
+		return (count % denominator == 0) ? 1 : 0;
+	}
+
+	return static_cast<int>(emission);
+}
+
+void ParticleSystem::check_bounds(ParticleEmitter & emitter,
+								  const Transform & transform) {
+	Vector2 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;
+
+	const double LEFT = offset.x - half_width;
+	const double RIGHT = offset.x + half_width;
+	const double TOP = offset.y - half_height;
+	const double BOTTOM = offset.y + half_height;
+
+	for (Particle & particle : emitter.data.particles) {
+		const Vector2 & position = particle.position;
+		bool within_bounds = (position.x >= LEFT && position.x <= RIGHT
+							  && position.y >= TOP && position.y <= BOTTOM);
+
+		if (!within_bounds) {
+			if (emitter.data.boundary.reset_on_exit) {
+				particle.active = false;
+			} else {
+				particle.velocity = {0, 0};
+				if (position.x < LEFT) particle.position.x = LEFT;
+				else if (position.x > RIGHT) particle.position.x = RIGHT;
+				if (position.y < TOP) particle.position.y = TOP;
+				else if (position.y > BOTTOM) particle.position.y = BOTTOM;
+			}
+		}
+	}
+}
+
+double ParticleSystem::generate_random_angle(double min_angle,
+											 double max_angle) const {
+	if (min_angle == max_angle) {
+		return min_angle;
+	} else if (min_angle < max_angle) {
+		return min_angle
+			   + static_cast<double>(std::rand()
+									 % static_cast<int>(max_angle - min_angle));
+	} else {
+		double angle_offset = (360 - min_angle) + max_angle;
+		double random_angle = min_angle
+							  + static_cast<double>(
+								  std::rand() % static_cast<int>(angle_offset));
+		return (random_angle >= 360) ? random_angle - 360 : random_angle;
+	}
+}
+
+double ParticleSystem::generate_random_speed(double min_speed,
+											 double max_speed) const {
+	if (min_speed == max_speed) {
+		return min_speed;
+	} else {
+		return min_speed
+			   + static_cast<double>(std::rand()
+									 % static_cast<int>(max_speed - min_speed));
+	}
+}
diff --git a/src/crepe/system/ParticleSystem.h b/src/crepe/system/ParticleSystem.h
index 3ac1d3f..d7ca148 100644
--- a/src/crepe/system/ParticleSystem.h
+++ b/src/crepe/system/ParticleSystem.h
@@ -1,18 +1,71 @@
 #pragma once
 
-#include "../api/ParticleEmitter.h"
+#include <cstdint>
 
-namespace crepe {
+#include "System.h"
 
-class ParticleSystem {
+namespace crepe {
+class ParticleEmitter;
+class Transform;
+/**
+ 	* \brief ParticleSystem class responsible for managing particle emission, updates, and bounds checking.
+ 	*/
+class ParticleSystem : public System {
 public:
-	ParticleSystem();
-	void update();
+	/**
+		* \brief Updates all particle emitters by emitting particles, updating particle states, and checking bounds.
+		*/
+	void update() override;
 
 private:
-	void emit_particle(ParticleEmitter & emitter); //emits a new particle
+	/**
+		* \brief Emits a particle from the specified emitter based on its emission properties.
+		* 
+		* \param emitter Reference to the ParticleEmitter.
+		* \param transform Const reference to the Transform component associated with the emitter.
+		*/
+	void emit_particle(ParticleEmitter & emitter, const Transform & transform);
+
+	/**
+		* \brief Calculates the number of times particles should be emitted based on emission rate and update count.
+		* 
+		* \param count Current update count.
+		* \param emission Emission rate.
+		* \return The number of particles to emit.
+		*/
+	int calculate_update(int count, double emission) const;
+
+	/**
+		* \brief Checks whether particles are within the emitter’s boundary, resets or stops particles if they exit.
+		* 
+		* \param emitter Reference to the ParticleEmitter.
+		* \param transform Const reference to the Transform component associated with the emitter.
+		*/
+	void check_bounds(ParticleEmitter & emitter, const Transform & transform);
 
-	float elapsed_time; //elapsed time since the last emission
+	/**
+		* \brief Generates a random angle for particle emission within the specified range.
+		* 
+		* \param min_angle Minimum emission angle in degrees.
+		* \param max_angle Maximum emission angle in degrees.
+		* \return Random angle in degrees.
+		*/
+	double generate_random_angle(double min_angle, double max_angle) const;
+
+	/**
+		* \brief Generates a random speed for particle emission within the specified range.
+		* 
+		* \param min_speed Minimum emission speed.
+		* \param max_speed Maximum emission speed.
+		* \return Random speed.
+		*/
+	double generate_random_speed(double min_speed, double max_speed) const;
+
+private:
+	//! Counter to count updates to determine how many times emit_particle is called.
+	unsigned int update_count = 0;
+	//! Determines the lowest amount of emission rate (1000 = 0.001 = 1 particle per 1000 updates).
+	static constexpr unsigned int MAX_UPDATE_COUNT = 100;
 };
 
 } // namespace crepe
diff --git a/src/crepe/system/PhysicsSystem.h b/src/crepe/system/PhysicsSystem.h
index cc13b70..038c120 100644
--- a/src/crepe/system/PhysicsSystem.h
+++ b/src/crepe/system/PhysicsSystem.h
@@ -1,5 +1,7 @@
 #pragma once
 
+#include "System.h"
+
 namespace crepe {
 /**
  * \brief System that controls all physics
@@ -7,18 +9,14 @@ namespace crepe {
  * This class is a physics system that uses a rigidbody and transform
  * to add physics to a game object.
  */
-class PhysicsSystem {
+class PhysicsSystem : public System {
 public:
 	/**
-	 * Constructor is default
-	 */
-	PhysicsSystem() = default;
-	/**
 	 * \brief updates the physics system.
 	 * 
 	 * It calculates new velocties and changes the postion in the transform.
 	 */
-	void update();
+	void update() override;
 };
 
 } // namespace crepe