Merge branch 'jaro/particle-system-improvement' of github.com:lonkaars/crepe

8 files changed, 99 insertions, 104 deletions

diff --git a/src/crepe/Particle.cpp b/src/crepe/Particle.cpp
index 485a0d4..b340826 100644
--- a/src/crepe/Particle.cpp
+++ b/src/crepe/Particle.cpp
@@ -2,8 +2,8 @@
 
 using namespace crepe;
 
-void Particle::reset(uint32_t lifespan, const vec2 & position, const vec2 & velocity,
-					 double angle) {
+void Particle::reset(unsigned int lifespan, const vec2 & position, const vec2 & velocity,
+					 float angle) {
 	// Initialize the particle state
 	this->time_in_life = 0;
 	this->lifespan = lifespan;
@@ -15,16 +15,17 @@ void Particle::reset(uint32_t lifespan, const vec2 & position, const vec2 & velo
 	this->force_over_time = {0, 0};
 }
 
-void Particle::update() {
+void Particle::update(double dt) {
 	// Deactivate particle if it has exceeded its lifespan
-	if (++time_in_life >= lifespan) {
+	time_in_life += dt;
+	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;
+	this->velocity += force_over_time * dt;
+	this->position += velocity * dt;
 }
 
 void Particle::stop_movement() {
diff --git a/src/crepe/Particle.h b/src/crepe/Particle.h
index d0397c9..ee0cd66 100644
--- a/src/crepe/Particle.h
+++ b/src/crepe/Particle.h
@@ -14,8 +14,6 @@ namespace crepe {
  * can also be reset or stopped.
  */
 class Particle {
-	// TODO: add friend particleSsytem and rendersystem. Unit test will fail.
-
 public:
 	//! Position of the particle in 2D space.
 	vec2 position;
@@ -24,13 +22,13 @@ public:
 	//! Accumulated force affecting the particle over time.
 	vec2 force_over_time;
 	//! Total lifespan of the particle in milliseconds.
-	uint32_t lifespan;
+	float 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;
+	float time_in_life = 0;
 	//! The angle at which the particle is oriented or moving.
-	double angle = 0;
+	float angle = 0;
 
 	/**
 	 * \brief Resets the particle with new properties.
@@ -43,14 +41,16 @@ 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 vec2 & position, const vec2 & velocity, double angle);
+	void reset(unsigned int lifespan, const vec2 & position, const vec2 & velocity,
+			   float 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.
+	 * \param dt The amount of fixed delta time that has passed.
 	 */
-	void update();
+	void update(double dt);
 	/**
 	 * \brief Stops the particle's movement.
 	 *
diff --git a/src/crepe/api/LoopManager.cpp b/src/crepe/api/LoopManager.cpp
index b5e5ff7..7a78019 100644
--- a/src/crepe/api/LoopManager.cpp
+++ b/src/crepe/api/LoopManager.cpp
@@ -65,6 +65,7 @@ void LoopManager::fixed_update() {
 	this->get_system<InputSystem>().update();
 	this->event_manager.dispatch_events();
 	this->get_system<ScriptSystem>().update();
+	this->get_system<ParticleSystem>().update();
 	this->get_system<AISystem>().update();
 	this->get_system<PhysicsSystem>().update();
 	this->get_system<CollisionSystem>().update();
diff --git a/src/crepe/api/ParticleEmitter.cpp b/src/crepe/api/ParticleEmitter.cpp
index 90b77a0..4f54bbd 100644
--- a/src/crepe/api/ParticleEmitter.cpp
+++ b/src/crepe/api/ParticleEmitter.cpp
@@ -1,11 +1,14 @@
 #include "ParticleEmitter.h"
+#include "api/Sprite.h"
 
 using namespace crepe;
 
-ParticleEmitter::ParticleEmitter(game_object_id_t game_object_id, const Data & data)
+ParticleEmitter::ParticleEmitter(game_object_id_t game_object_id, const Sprite & sprite,
+								 const Data & data)
 	: Component(game_object_id),
+	  sprite(sprite),
 	  data(data) {
 	for (size_t i = 0; i < this->data.max_particles; i++) {
-		this->data.particles.emplace_back();
+		this->particles.emplace_back();
 	}
 }
diff --git a/src/crepe/api/ParticleEmitter.h b/src/crepe/api/ParticleEmitter.h
index b83fd61..8ac2e72 100644
--- a/src/crepe/api/ParticleEmitter.h
+++ b/src/crepe/api/ParticleEmitter.h
@@ -1,7 +1,11 @@
 #pragma once
 
+#include <cmath>
 #include <vector>
 
+#include "system/ParticleSystem.h"
+#include "system/RenderSystem.h"
+
 #include "Component.h"
 #include "Particle.h"
 #include "types.h"
@@ -26,15 +30,18 @@ public:
 	 */
 	struct Boundary {
 		//! boundary width (midpoint is emitter location)
-		double width = 0.0;
+		float width = INFINITY;
 		//! boundary height (midpoint is emitter location)
-		double height = 0.0;
+		float height = INFINITY;
 		//! boundary offset from particle emitter location
 		vec2 offset;
 		//! reset on exit or stop velocity and set max postion
 		bool reset_on_exit = false;
 	};
 
+	//! sprite reference of displayed sprite
+	const Sprite & sprite;
+
 	/**
 	 * \brief Holds parameters that control particle emission.
 	 *
@@ -42,32 +49,28 @@ public:
 	 * and the sprite used for rendering particles.
 	 */
 	struct Data {
-		//! position of the emitter
-		vec2 position;
+		//! offset of the emitter relative to transform
+		vec2 offset;
 		//! 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;
+		const unsigned int max_particles = 256;
+		//! rate of particle emission per second
+		float emission_rate = 50;
 		//! min speed of the particles
-		double min_speed = 0;
+		float min_speed = 100;
 		//! min speed of the particles
-		double max_speed = 0;
+		float max_speed = 100;
 		//! min angle of particle emission
-		double min_angle = 0;
+		float 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;
+		float max_angle = 0;
+		//! begin Lifespan of particle in seconds (only visual)
+		float begin_lifespan = 0.0;
+		//! end Lifespan of particle in seconds
+		float end_lifespan = 10.0;
 		//! force over time (physics)
 		vec2 force_over_time;
 		//! particle boundary
 		Boundary boundary;
-		//! collection of particles
-		std::vector<Particle> particles;
-		//! sprite reference
-		const Sprite & sprite;
 	};
 
 public:
@@ -75,11 +78,21 @@ 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);
+	ParticleEmitter(game_object_id_t game_object_id, const Sprite & sprite, const Data & data);
 
 public:
 	//! Configuration data for particle emission settings.
 	Data data;
+
+private:
+	//! Only ParticleSystem can move and read particles
+	friend ParticleSystem;
+	//! Only RenderSystem can read particles
+	friend RenderSystem;
+	//! Saves time left over from last update event.
+	float spawn_accumulator = 0;
+	//! collection of particles
+	std::vector<Particle> particles;
 };
 
 } // namespace crepe
diff --git a/src/crepe/system/ParticleSystem.cpp b/src/crepe/system/ParticleSystem.cpp
index b14c52f..35a1d41 100644
--- a/src/crepe/system/ParticleSystem.cpp
+++ b/src/crepe/system/ParticleSystem.cpp
@@ -1,3 +1,4 @@
+#include <chrono>
 #include <cmath>
 #include <cstdlib>
 #include <ctime>
@@ -5,6 +6,7 @@
 #include "../api/ParticleEmitter.h"
 #include "../api/Transform.h"
 #include "../manager/ComponentManager.h"
+#include "../manager/LoopTimerManager.h"
 
 #include "ParticleSystem.h"
 
@@ -12,7 +14,11 @@ using namespace crepe;
 
 void ParticleSystem::update() {
 	// Get all emitters
-	ComponentManager & mgr = this->mediator.component_manager;
+	const Mediator & mediator = this->mediator;
+	LoopTimerManager & loop_timer = mediator.loop_timer;
+	ComponentManager & mgr = mediator.component_manager;
+	float dt = loop_timer.get_scaled_fixed_delta_time().count();
+
 	RefVector<ParticleEmitter> emitters = mgr.get_components_by_type<ParticleEmitter>();
 
 	for (ParticleEmitter & emitter : emitters) {
@@ -21,38 +27,39 @@ void ParticleSystem::update() {
 			= 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);
+		emitter.spawn_accumulator += emitter.data.emission_rate * dt;
+		while (emitter.spawn_accumulator >= 1.0) {
+			this->emit_particle(emitter, transform);
+			emitter.spawn_accumulator -= 1.0;
 		}
 
 		// Update all particles
-		for (Particle & particle : emitter.data.particles) {
+		for (Particle & particle : emitter.particles) {
 			if (particle.active) {
-				particle.update();
+				particle.update(dt);
 			}
 		}
 
 		// Check if within boundary
-		check_bounds(emitter, transform);
+		this->check_bounds(emitter, transform);
 	}
-
-	this->update_count = (this->update_count + 1) % this->MAX_UPDATE_COUNT;
 }
 
 void ParticleSystem::emit_particle(ParticleEmitter & emitter, const Transform & transform) {
 	constexpr float DEG_TO_RAD = M_PI / 180.0;
 
-	vec2 initial_position = emitter.data.position + transform.position;
-	float random_angle = generate_random_angle(emitter.data.min_angle, emitter.data.max_angle);
+	vec2 initial_position = emitter.data.offset + transform.position;
+	float random_angle
+		= this->generate_random_angle(emitter.data.min_angle, emitter.data.max_angle);
 
-	float random_speed = generate_random_speed(emitter.data.min_speed, emitter.data.max_speed);
+	float random_speed
+		= this->generate_random_speed(emitter.data.min_speed, emitter.data.max_speed);
 	float angle_radians = random_angle * DEG_TO_RAD;
 
 	vec2 velocity
 		= {random_speed * std::cos(angle_radians), random_speed * std::sin(angle_radians)};
 
-	for (Particle & particle : emitter.data.particles) {
+	for (Particle & particle : emitter.particles) {
 		if (!particle.active) {
 			particle.reset(emitter.data.end_lifespan, initial_position, velocity,
 						   random_angle);
@@ -61,66 +68,54 @@ void ParticleSystem::emit_particle(ParticleEmitter & emitter, const Transform &
 	}
 }
 
-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) {
-	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;
+	vec2 offset = emitter.data.boundary.offset + transform.position + emitter.data.offset;
+	float half_width = emitter.data.boundary.width / 2.0;
+	float 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;
+	float left = offset.x - half_width;
+	float right = offset.x + half_width;
+	float top = offset.y - half_height;
+	float bottom = offset.y + half_height;
 
-	for (Particle & particle : emitter.data.particles) {
+	for (Particle & particle : emitter.particles) {
 		const vec2 & position = particle.position;
-		bool within_bounds = (position.x >= LEFT && position.x <= RIGHT && position.y >= TOP
-							  && position.y <= BOTTOM);
-
+		bool within_bounds = (position.x >= left && position.x <= right && position.y >= top
+							  && position.y <= bottom);
+		//if not within bounds do a reset or stop velocity
 		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;
+				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 {
+float ParticleSystem::generate_random_angle(float min_angle, float 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));
+			   + static_cast<float>(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));
+		float angle_offset = (360 - min_angle) + max_angle;
+		float random_angle
+			= min_angle + static_cast<float>(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 {
+float ParticleSystem::generate_random_speed(float min_speed, float 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));
+			   + static_cast<float>(std::rand() % static_cast<int>(max_speed - min_speed));
 	}
 }
diff --git a/src/crepe/system/ParticleSystem.h b/src/crepe/system/ParticleSystem.h
index 068f01c..154521d 100644
--- a/src/crepe/system/ParticleSystem.h
+++ b/src/crepe/system/ParticleSystem.h
@@ -32,16 +32,6 @@ private:
 	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.
 	 *
@@ -57,7 +47,7 @@ private:
 	 * \param max_angle Maximum emission angle in degrees.
 	 * \return Random angle in degrees.
 	 */
-	double generate_random_angle(double min_angle, double max_angle) const;
+	float generate_random_angle(float min_angle, float max_angle) const;
 
 	/**
 	 * \brief Generates a random speed for particle emission within the specified range.
@@ -66,15 +56,7 @@ private:
 	 * \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;
+	float generate_random_speed(float min_speed, float max_speed) const;
 };
 
 } // namespace crepe
diff --git a/src/crepe/system/RenderSystem.cpp b/src/crepe/system/RenderSystem.cpp
index afd9548..505433a 100644
--- a/src/crepe/system/RenderSystem.cpp
+++ b/src/crepe/system/RenderSystem.cpp
@@ -83,11 +83,11 @@ bool RenderSystem::render_particle(const Sprite & sprite, const double & scale)
 	bool rendering_particles = false;
 
 	for (const ParticleEmitter & em : emitters) {
-		if (&em.data.sprite != &sprite) continue;
+		if (&em.sprite != &sprite) continue;
 		rendering_particles = true;
 		if (!em.active) continue;
 
-		for (const Particle & p : em.data.particles) {
+		for (const Particle & p : em.particles) {
 			if (!p.active) continue;
 
 			ctx.draw(SDLContext::RenderContext{