2 files changed, 117 insertions, 24 deletions

diff --git a/src/crepe/system/RenderSystem.cpp b/src/crepe/system/RenderSystem.cpp
index fa3d0de..e379771 100644
--- a/src/crepe/system/RenderSystem.cpp
+++ b/src/crepe/system/RenderSystem.cpp
@@ -1,44 +1,104 @@
+#include <algorithm>
+#include <cassert>
+#include <cmath>
 #include <functional>
+#include <iostream>
+#include <stdexcept>
 #include <vector>
 
 #include "../ComponentManager.h"
+#include "../api/ParticleEmitter.h"
 #include "../api/Sprite.h"
 #include "../api/Transform.h"
+#include "../api/Vector2.h"
 #include "../facade/SDLContext.h"
-#include "../util/Log.h"
 
 #include "RenderSystem.h"
 
 using namespace crepe;
+using namespace std;
 
-void RenderSystem::clear_screen() const { SDLContext::get_instance().clear_screen(); }
+void RenderSystem::clear_screen() { this->context.clear_screen(); }
 
-void RenderSystem::present_screen() const { SDLContext::get_instance().present_screen(); }
+void RenderSystem::present_screen() { this->context.present_screen(); }
 void RenderSystem::update_camera() {
 	ComponentManager & mgr = this->component_manager;
 
 	std::vector<std::reference_wrapper<Camera>> cameras = mgr.get_components_by_type<Camera>();
 
+	if (cameras.size() == 0) throw std::runtime_error("No cameras in current scene");
+
 	for (Camera & cam : cameras) {
-		SDLContext::get_instance().camera(cam);
-		this->curr_cam = &cam;
+		if (!cam.active) continue;
+		this->context.set_camera(cam);
+		this->curr_cam_ref = &cam;
 	}
 }
-void RenderSystem::render_sprites() const {
-	ComponentManager & mgr = this->component_manager;
 
-	std::vector<std::reference_wrapper<Sprite>> sprites = mgr.get_components_by_type<Sprite>();
+bool sorting_comparison(const Sprite & a, const Sprite & b) {
+	if (a.sorting_in_layer < b.sorting_in_layer) return true;
+	if (a.sorting_in_layer == b.sorting_in_layer) return a.order_in_layer < b.order_in_layer;
 
-	SDLContext & render = SDLContext::get_instance();
-	for (const Sprite & sprite : sprites) {
-		auto transforms = mgr.get_components_by_id<Transform>(sprite.game_object_id);
-		render.draw(sprite, transforms[0], *curr_cam);
-	}
+	return false;
+}
+
+std::vector<std::reference_wrapper<Sprite>>
+RenderSystem::sort(std::vector<std::reference_wrapper<Sprite>> & objs) const {
+
+	std::vector<std::reference_wrapper<Sprite>> sorted_objs(objs);
+	std::sort(sorted_objs.begin(), sorted_objs.end(), sorting_comparison);
+
+	return sorted_objs;
 }
 
 void RenderSystem::update() {
 	this->clear_screen();
 	this->update_camera();
-	this->render_sprites();
+	this->render();
 	this->present_screen();
 }
+
+bool RenderSystem::render_particle(const Sprite & sprite, const double & scale) {
+
+	ComponentManager & mgr = this->component_manager;
+
+	vector<reference_wrapper<ParticleEmitter>> emitters
+		= mgr.get_components_by_id<ParticleEmitter>(sprite.game_object_id);
+
+	bool rendering_particles = false;
+
+	for (const ParticleEmitter & em : emitters) {
+		if (!(&em.data.sprite == &sprite)) continue;
+		rendering_particles = true;
+		if (!em.active) continue;
+
+		for (const Particle & p : em.data.particles) {
+			if (!p.active) continue;
+			this->context.draw_particle(sprite, p.position, p.angle, scale,
+										*this->curr_cam_ref);
+		}
+	}
+	return rendering_particles;
+}
+void RenderSystem::render_normal(const Sprite & sprite, const Transform & tm) {
+	this->context.draw(sprite, tm, *this->curr_cam_ref);
+}
+
+void RenderSystem::render() {
+
+	ComponentManager & mgr = this->component_manager;
+	vector<reference_wrapper<Sprite>> sprites = mgr.get_components_by_type<Sprite>();
+	vector<reference_wrapper<Sprite>> sorted_sprites = this->sort(sprites);
+
+	for (const Sprite & sprite : sorted_sprites) {
+		if (!sprite.active) continue;
+		const Transform & transform
+			= mgr.get_components_by_id<Transform>(sprite.game_object_id).front().get();
+
+		bool rendered_particles = this->render_particle(sprite, transform.scale);
+
+		if (rendered_particles) continue;
+
+		this->render_normal(sprite, transform);
+	}
+}
diff --git a/src/crepe/system/RenderSystem.h b/src/crepe/system/RenderSystem.h
index 87ec494..d25a6e3 100644
--- a/src/crepe/system/RenderSystem.h
+++ b/src/crepe/system/RenderSystem.h
@@ -1,18 +1,24 @@
 #pragma once
 
-#include "api/Camera.h"
+#include <functional>
+#include <vector>
+
+#include "facade/SDLContext.h"
 
 #include "System.h"
+#include <cmath>
 
 namespace crepe {
 
+class Camera;
+class Sprite;
+
 /**
  * \class RenderSystem
  * \brief Manages rendering operations for all game objects.
  *
- * RenderSystem is responsible for rendering sprites, clearing and presenting the screen, and
- * managing the active camera. It functions as a singleton, providing centralized rendering
- * services for the application.
+ * RenderSystem is responsible for rendering, clearing and presenting the screen, and
+ * managing the active camera. 
  */
 class RenderSystem : public System {
 public:
@@ -25,20 +31,45 @@ public:
 
 private:
 	//! Clears the screen in preparation for rendering.
-	void clear_screen() const;
+	void clear_screen();
 
 	//! Presents the rendered frame to the display.
-	void present_screen() const;
+	void present_screen();
 
 	//! Updates the active camera used for rendering.
 	void update_camera();
 
-	//! Renders all active sprites to the screen.
-	void render_sprites() const;
+	//! Renders the whole screen
+	void render();
+
+	/**
+	 * \brief Renders all the particles on the screen from a given sprite.
+	 *
+	 * \param sprite renders the particles with given texture
+	 * \param tm the Transform component for scale
+	 * \return true if particles have been rendered
+	 */
+	bool render_particle(const Sprite & sprite, const double & scale);
+
+	/**
+	 * \brief renders a sprite with a Transform component on the screen 
+	 *
+	 * \param sprite  the sprite component that holds all the data
+	 * \param tm the Transform component that holds the position,rotation and scale 
+	 */
+	void render_normal(const Sprite & sprite, const Transform & tm);
+
+	/**
+	 * \brief sort a vector sprite objects with
+	 *
+	 * \param objs the vector that will do a sorting algorithm on 
+	 * \return returns a sorted reference vector
+	 */
+	std::vector<std::reference_wrapper<Sprite>>
+	sort(std::vector<std::reference_wrapper<Sprite>> & objs) const;
 
 	/**
 	 * \todo Include color handling for sprites.
-	 * \todo Implement particle emitter rendering with sprites.
 	 * \todo Add text rendering using SDL_ttf for text components.
 	 * \todo Implement a text component and a button component.
 	 * \todo Ensure each sprite is checked for active status before rendering.
@@ -48,8 +79,10 @@ private:
 
 private:
 	//! Pointer to the current active camera for rendering
-	Camera * curr_cam = nullptr;
+	Camera * curr_cam_ref = nullptr;
 	// TODO: needs a better solution
+
+	SDLContext & context = SDLContext::get_instance();
 };
 
 } // namespace crepe