particle updated

2 files changed, 131 insertions, 38 deletions

diff --git a/src/crepe/system/ParticleSystem.cpp b/src/crepe/system/ParticleSystem.cpp
index 397b586..23534a3 100644
--- a/src/crepe/system/ParticleSystem.cpp
+++ b/src/crepe/system/ParticleSystem.cpp
@@ -1,62 +1,149 @@
 #include <cmath>
 #include <ctime>
+#include <cstdlib>
 
-#include "../ComponentManager.h"
-#include "../api/ParticleEmitter.h"
+#include "api/ParticleEmitter.h"
+#include "api/Vector2.h"
 
+#include "ComponentManager.h"
 #include "ParticleSystem.h"
 
 using namespace crepe;
 
-ParticleSystem::ParticleSystem() : elapsed_time(0.0f) {}
+ParticleSystem::ParticleSystem() {}
 
 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();
+
+		//	Check if within boundary
+		check_bounds(emitter,transform);
+		
+		// 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 (size_t j = 0; j < emitter.data.particles.size(); j++) {
+			if (emitter.data.particles[j].active) {
+				emitter.data.particles[j].update();
 			}
 		}
 	}
+	update_count++;
+	if(update_count == MAX_UPDATE_COUNT) update_count = 0;
 }
 
-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);
+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 min_angle = emitter.data.min_angle;
+	double max_angle = emitter.data.max_angle;
+	double random_angle;
+	
+	if (min_angle <= max_angle) {
+			// Standard range (e.g., 10 to 20 degrees)
+			double angle_offset = max_angle - min_angle;
+			random_angle = min_angle + static_cast<double>(std::rand() % static_cast<uint32_t>(angle_offset));
 	} else {
-		random_angle = emitter.min_angle
-					   + (std::rand()
-						  % (static_cast<uint32_t>(emitter.max_angle
-												   - emitter.min_angle + 1)));
+			// Wrap-around range (e.g., 350 to 10 degrees)
+			double angle_offset = (360 - min_angle) + max_angle;
+			random_angle = min_angle + static_cast<double>(std::rand() % static_cast<uint32_t>(angle_offset));
+			
+			// Wrap around to keep random_angle within 0-360 degrees
+			if (random_angle >= 360) {
+					random_angle -= 360;
+			}
 	}
-	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);
+
+	// Generate a random speed between min_speed and max_speed
+	double speed_offset = emitter.data.max_speed - emitter.data.min_speed;
+	double random_speed = emitter.data.min_speed + static_cast<double>(std::rand() % static_cast<uint32_t>(speed_offset));
+
+	// Convert random_angle to radians
+	double angle_radians = random_angle * DEG_TO_RAD;
+
+	Vector2 velocity = {
+        random_speed * std::cos(angle_radians),
+        random_speed * std::sin(angle_radians)
+    };
+
+
+	for (size_t i = 0; i < emitter.data.particles.size(); i++) {
+		if (!emitter.data.particles[i].active) {
+			emitter.data.particles[i].reset(emitter.data.end_lifespan, initial_position,velocity,random_angle);
 			break;
 		}
 	}
 }
+
+int ParticleSystem::calculate_update(int count, double emission) {
+
+		//get interger part of the emission
+		double integer_part = std::floor(emission);
+
+    // Get the fractional part of the emission
+    double fractional_part = emission - integer_part;
+
+    // Convert the fractional part to a denominator value
+    int denominator = static_cast<int>(1.0 / fractional_part);
+
+    // For emissions like 0.01, 0.1, 0.5, etc., calculate the update frequency
+    if (fractional_part > 0) {
+			// Calculate how often the update should be triggered based on the fractional part
+			if (count % denominator == 0) {
+				return 1;
+			} else {
+				return 0;
+			}
+    }
+		
+    // For integer emissions, return the emission directly
+    return static_cast<int>(emission);
+}
+
+void ParticleSystem::check_bounds(ParticleEmitter & emitter,const Transform& transform)
+{
+		Vector2 offset = emitter.data.boundary.boundary_offset + transform.position + emitter.data.position;
+		double half_width = emitter.data.boundary.boundary_width / 2.0;
+		double half_height = emitter.data.boundary.boundary_height / 2.0;
+
+		// Define boundary edges
+		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;
+
+		std::vector<Particle>& particles = emitter.data.particles;
+		for (Particle& particle : particles)
+		{
+				const Vector2& position = particle.position;
+
+				// Check if particle is within bounds
+				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};
+								//todo add that particle goes back to boundary
+						}
+				}
+		}
+}
diff --git a/src/crepe/system/ParticleSystem.h b/src/crepe/system/ParticleSystem.h
index 3ac1d3f..3b9cb54 100644
--- a/src/crepe/system/ParticleSystem.h
+++ b/src/crepe/system/ParticleSystem.h
@@ -10,9 +10,15 @@ public:
 	void update();
 
 private:
-	void emit_particle(ParticleEmitter & emitter); //emits a new particle
+	void emit_particle(ParticleEmitter & emitter,const Transform& transform);
+	int calculate_update(int count, double emission);
+	void check_bounds(ParticleEmitter & emitter,const Transform& transform);
 
-	float elapsed_time; //elapsed time since the last emission
+private:
+	//! counter to count updates to determine how many times emit_particle is called.
+	uint32_t update_count = 0;
+	//! determines the lowest amount of emissionrate (1000 = 0.001 = 1 particle per 1000 updates).
+	const uint32_t MAX_UPDATE_COUNT = 100;
 };
 
 } // namespace crepe