9 files changed, 285 insertions, 103 deletions

diff --git a/src/crepe/api/Color.cpp b/src/crepe/api/Color.cpp
index 9e5f187..29bd77a 100644
--- a/src/crepe/api/Color.cpp
+++ b/src/crepe/api/Color.cpp
@@ -2,32 +2,11 @@
 
 using namespace crepe;
 
-Color Color::white = Color(255, 255, 255, 0);
-Color Color::red = Color(255, 0, 0, 0);
-Color Color::green = Color(0, 255, 0, 0);
-Color Color::blue = Color(0, 0, 255, 0);
-Color Color::black = Color(0, 0, 0, 0);
-Color Color::cyan = Color(0, 255, 255, 0);
-Color Color::yellow = Color(255, 255, 0, 0);
-Color Color::magenta = Color(255, 0, 255, 0);
-
-Color::Color(uint8_t red, uint8_t green, uint8_t blue, uint8_t alpha) {
-	this->a = alpha;
-	this->r = red;
-	this->g = green;
-	this->b = blue;
-};
-
-const Color & Color::get_white() { return Color::white; };
-
-const Color & Color::get_red() { return Color::red; };
-const Color & Color::get_green() { return Color::green; };
-const Color & Color::get_blue() { return Color::blue; };
-
-const Color & Color::get_black() { return Color::black; };
-
-const Color & Color::get_cyan() { return Color::cyan; };
-
-const Color & Color::get_yellow() { return Color::yellow; };
-
-const Color & Color::get_magenta() { return Color::magenta; };
+const Color Color::WHITE{0xff, 0xff, 0xff};
+const Color Color::RED{0xff, 0x00, 0x00};
+const Color Color::GREEN{0x00, 0xff, 0x00};
+const Color Color::BLUE{0x00, 0x00, 0xff};
+const Color Color::BLACK{0x00, 0x00, 0x00};
+const Color Color::CYAN{0x00, 0xff, 0xff};
+const Color Color::YELLOW{0xff, 0xff, 0x00};
+const Color Color::MAGENTA{0xff, 0x00, 0xff};
diff --git a/src/crepe/api/Color.h b/src/crepe/api/Color.h
index aa47bf4..84edb5c 100644
--- a/src/crepe/api/Color.h
+++ b/src/crepe/api/Color.h
@@ -4,41 +4,20 @@
 
 namespace crepe {
 
-// TODO: make Color a struct w/o constructors/destructors
-class Color {
-
-	// FIXME: can't these colors be defined as a `static constexpr const Color`
-	// instead?
-
-public:
-	Color(uint8_t red, uint8_t green, uint8_t blue, uint8_t alpha);
-	static const Color & get_white();
-	static const Color & get_red();
-	static const Color & get_green();
-	static const Color & get_blue();
-	static const Color & get_cyan();
-	static const Color & get_magenta();
-	static const Color & get_yellow();
-	static const Color & get_black();
-
-private:
-	// TODO: why are these private!?
-	uint8_t r;
-	uint8_t g;
-	uint8_t b;
-	uint8_t a;
-
-	static Color white;
-	static Color red;
-	static Color green;
-	static Color blue;
-	static Color cyan;
-	static Color magenta;
-	static Color yellow;
-	static Color black;
-
-private:
-	friend class SDLContext;
+struct Color {
+	uint8_t r = 0x00;
+	uint8_t g = 0x00;
+	uint8_t b = 0x00;
+	uint8_t a = 0xff;
+
+	static const Color WHITE;
+	static const Color RED;
+	static const Color GREEN;
+	static const Color BLUE;
+	static const Color CYAN;
+	static const Color MAGENTA;
+	static const Color YELLOW;
+	static const Color BLACK;
 };
 
 } // namespace crepe
diff --git a/src/crepe/api/Sprite.h b/src/crepe/api/Sprite.h
index 0192793..74a55d4 100644
--- a/src/crepe/api/Sprite.h
+++ b/src/crepe/api/Sprite.h
@@ -2,8 +2,9 @@
 
 #include <memory>
 
+#include "../Component.h"
+
 #include "Color.h"
-#include "Component.h"
 #include "Texture.h"
 
 namespace crepe {
diff --git a/src/crepe/facade/SDLContext.h b/src/crepe/facade/SDLContext.h
index 718c40f..9a514cb 100644
--- a/src/crepe/facade/SDLContext.h
+++ b/src/crepe/facade/SDLContext.h
@@ -20,9 +20,6 @@ namespace crepe {
 // typedef is unusable when crepe is packaged. Wouter will fix this later.
 typedef SDL_Keycode CREPE_KEYCODES;
 
-class Texture;
-class LoopManager;
-
 /**
  * \class SDLContext
  * \brief Facade for the SDL library
@@ -90,9 +87,6 @@ private:
 	//! Will use the funtions: texture_from_path, get_width,get_height.
 	friend class Texture;
 
-	//! Will use the funtions: texture_from_path, get_width,get_height.
-	friend class Animator;
-
 	/**
 	 * \brief Loads a texture from a file path.
 	 * \param path Path to the image file.
diff --git a/src/crepe/system/RenderSystem.cpp b/src/crepe/system/RenderSystem.cpp
index c137de1..bc5422d 100644
--- a/src/crepe/system/RenderSystem.cpp
+++ b/src/crepe/system/RenderSystem.cpp
@@ -1,4 +1,7 @@
+#include <algorithm>
+#include <cassert>
 #include <cmath>
+#include <stdexcept>
 #include <vector>
 
 #include "../ComponentManager.h"
@@ -11,25 +14,52 @@
 #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;
 
-	auto cameras = mgr.get_components_by_type<Camera>();
+	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().set_camera(cam);
-		this->curr_cam = &cam;
+		this->context.set_camera(cam);
+		this->curr_cam_ref = &cam;
 	}
 }
 
+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;
+
+	return false;
+}
+
+std::vector<std::reference_wrapper<Sprite>>
+RenderSystem::sort(std::vector<std::reference_wrapper<Sprite>> & objs) {
+
+	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();
+	this->present_screen();
+}
+
 bool RenderSystem::render_particle(const Sprite & sprite, const double & scale) const {
 
 	ComponentManager & mgr = this->component_manager;
-	SDLContext & render = SDLContext::get_instance();
 
 	auto emitters = mgr.get_components_by_id<ParticleEmitter>(sprite.game_object_id);
 
@@ -43,7 +73,7 @@ bool RenderSystem::render_particle(const Sprite & sprite, const double & scale)
 
 		for (const Particle & p : em.data.particles) {
 			if (!p.active) continue;
-			render.draw_particle(sprite, p.position, p.angle, scale, *this->curr_cam);
+			this->context.draw_particle(sprite, p.position, p.angle, scale, *this->curr_cam);
 		}
 	}
 	return rendering_particles;
@@ -51,17 +81,17 @@ bool RenderSystem::render_particle(const Sprite & sprite, const double & scale)
 void RenderSystem::render_normal(const Sprite & sprite, const Transform & tm) const {
 
 	ComponentManager & mgr = this->component_manager;
-	SDLContext & render = SDLContext::get_instance();
 
-	render.draw(sprite, tm, *curr_cam);
+	this->context.draw(sprite, tm, *this->curr_cam);
 }
 
 void RenderSystem::render() const {
 
 	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);
 
-	auto sprites = mgr.get_components_by_type<Sprite>();
-	for (const Sprite & sprite : 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();
@@ -73,10 +103,3 @@ void RenderSystem::render() const {
 		this->render_normal(sprite, transform);
 	}
 }
-
-void RenderSystem::update() {
-	this->clear_screen();
-	this->update_camera();
-	this->render();
-	this->present_screen();
-}
diff --git a/src/crepe/system/RenderSystem.h b/src/crepe/system/RenderSystem.h
index 8841f72..b9033fb 100644
--- a/src/crepe/system/RenderSystem.h
+++ b/src/crepe/system/RenderSystem.h
@@ -1,21 +1,24 @@
 #pragma once
 
-#include "api/Camera.h"
-#include "api/Sprite.h"
-#include "api/Transform.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:
@@ -28,10 +31,10 @@ 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();
@@ -54,7 +57,16 @@ private:
 	 * \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) const;
+	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);
 
 	/**
 	 * \todo Include color handling for sprites.
@@ -67,8 +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
diff --git a/src/example/rendering.cpp b/src/example/rendering.cpp
index c9e62f1..ecd3f6a 100644
--- a/src/example/rendering.cpp
+++ b/src/example/rendering.cpp
@@ -30,14 +30,27 @@ int main() {
 	// Normal adding components
 	{
 		Color color(0, 0, 0, 0);
-		obj.add_component<Sprite>(make_shared<Texture>("../asset/texture/img.png"), color,
-								  FlipSettings{false, false});
+		Sprite & sprite
+			= obj.add_component<Sprite>(make_shared<Texture>("../asset/texture/img.png"),
+										color, FlipSettings{false, false});
+		sprite.sorting_in_layer = 2;
+		sprite.order_in_layer = 1;
 		obj.add_component<Camera>(Color::get_red());
 	}
 	{
 		Color color(0, 0, 0, 0);
-		obj1.add_component<Sprite>(make_shared<Texture>("../asset/texture/second.png"), color,
-								   FlipSettings{true, true});
+		Sprite & sprite = obj1.add_component<Sprite>(
+			make_shared<Texture>("../asset/texture/img.png"), color, FlipSettings{true, true});
+		sprite.sorting_in_layer = 2;
+		sprite.order_in_layer = 2;
+	}
+
+	{
+		Color color(0, 0, 0, 0);
+		Sprite & sprite = obj2.add_component<Sprite>(
+			make_shared<Texture>("../asset/texture/img.png"), color, FlipSettings{true, true});
+		sprite.sorting_in_layer = 1;
+		sprite.order_in_layer = 2;
 	}
 
 	/*
@@ -48,8 +61,12 @@ int main() {
 	}
 	*/
 
+	sys.update();
+	/*
+
 	auto start = std::chrono::steady_clock::now();
 	while (std::chrono::steady_clock::now() - start < std::chrono::seconds(5)) {
 		sys.update();
 	}
+	*/
 }
diff --git a/src/test/CMakeLists.txt b/src/test/CMakeLists.txt
index 49c8151..1c93220 100644
--- a/src/test/CMakeLists.txt
+++ b/src/test/CMakeLists.txt
@@ -3,5 +3,6 @@ target_sources(test_main PUBLIC
 	PhysicsTest.cpp
 	ScriptTest.cpp
 	ParticleTest.cpp
+	RenderSystemTest.cpp
 )
 
diff --git a/src/test/RenderSystemTest.cpp b/src/test/RenderSystemTest.cpp
new file mode 100644
index 0000000..ac479d3
--- /dev/null
+++ b/src/test/RenderSystemTest.cpp
@@ -0,0 +1,174 @@
+#include "api/Camera.h"
+#include <functional>
+#include <gtest/gtest.h>
+#include <memory>
+#include <vector>
+
+#define private public
+#define protected public
+
+#include <crepe/ComponentManager.h>
+#include <crepe/api/Color.h>
+#include <crepe/api/GameObject.h>
+#include <crepe/api/Sprite.h>
+#include <crepe/api/Texture.h>
+
+#include <crepe/system/RenderSystem.h>
+
+using namespace std;
+using namespace crepe;
+using namespace testing;
+
+class RenderSystemTest : public Test {
+public:
+	ComponentManager mgr{};
+	RenderSystem sys{mgr};
+	GameObject entity1 = this->mgr.new_object("name");
+	GameObject entity2 = this->mgr.new_object("name");
+	GameObject entity3 = this->mgr.new_object("name");
+	GameObject entity4 = this->mgr.new_object("name");
+
+	void SetUp() override {
+		auto & sprite1
+			= entity1.add_component<Sprite>(make_shared<Texture>("../asset/texture/img.png"),
+											Color(0, 0, 0, 0), FlipSettings{false, false});
+		ASSERT_NE(sprite1.sprite_image.get(), nullptr);
+		sprite1.order_in_layer = 5;
+		sprite1.sorting_in_layer = 5;
+		EXPECT_EQ(sprite1.order_in_layer, 5);
+		EXPECT_EQ(sprite1.sorting_in_layer, 5);
+		auto & sprite2
+			= entity2.add_component<Sprite>(make_shared<Texture>("../asset/texture/img.png"),
+											Color(0, 0, 0, 0), FlipSettings{false, false});
+		ASSERT_NE(sprite2.sprite_image.get(), nullptr);
+		sprite2.sorting_in_layer = 2;
+		sprite2.order_in_layer = 1;
+
+		EXPECT_EQ(sprite2.sorting_in_layer, 2);
+		EXPECT_EQ(sprite2.order_in_layer, 1);
+
+		auto & sprite3
+			= entity3.add_component<Sprite>(make_shared<Texture>("../asset/texture/img.png"),
+											Color(0, 0, 0, 0), FlipSettings{false, false});
+		ASSERT_NE(sprite3.sprite_image.get(), nullptr);
+		sprite3.sorting_in_layer = 1;
+		sprite3.order_in_layer = 2;
+
+		EXPECT_EQ(sprite3.sorting_in_layer, 1);
+		EXPECT_EQ(sprite3.order_in_layer, 2);
+
+		auto & sprite4
+			= entity4.add_component<Sprite>(make_shared<Texture>("../asset/texture/img.png"),
+											Color(0, 0, 0, 0), FlipSettings{false, false});
+		ASSERT_NE(sprite4.sprite_image.get(), nullptr);
+		sprite4.sorting_in_layer = 1;
+		sprite4.order_in_layer = 1;
+		EXPECT_EQ(sprite4.sorting_in_layer, 1);
+		EXPECT_EQ(sprite4.order_in_layer, 1);
+	}
+};
+
+TEST_F(RenderSystemTest, expected_throws) {
+	GameObject entity1 = this->mgr.new_object("NAME");
+
+	// no texture img
+	EXPECT_ANY_THROW({
+		entity1.add_component<Sprite>(make_shared<Texture>("NO_IMAGE"), Color(0, 0, 0, 0),
+									  FlipSettings{false, false});
+	});
+
+	// No camera
+	EXPECT_ANY_THROW({ this->sys.update(); });
+}
+
+TEST_F(RenderSystemTest, make_sprites) {}
+
+TEST_F(RenderSystemTest, sorting_sprites) {
+	vector<reference_wrapper<Sprite>> sprites = this->mgr.get_components_by_type<Sprite>();
+	ASSERT_EQ(sprites.size(), 4);
+
+	vector<reference_wrapper<Sprite>> sorted_sprites = this->sys.sort(sprites);
+	ASSERT_EQ(sorted_sprites.size(), 4);
+
+	// Expected order after sorting:
+	// 1. sorting_in_layer: 1, order_in_layer: 1 (entity4)
+	// 2. sorting_in_layer: 1, order_in_layer: 2 (entity3)
+	// 3. sorting_in_layer: 2, order_in_layer: 1 (entity2)
+	// 4. sorting_in_layer: 5, order_in_layer: 5 (entity1)
+
+	EXPECT_EQ(sorted_sprites[0].get().sorting_in_layer, 1);
+	EXPECT_EQ(sorted_sprites[0].get().order_in_layer, 1);
+
+	EXPECT_EQ(sorted_sprites[1].get().sorting_in_layer, 1);
+	EXPECT_EQ(sorted_sprites[1].get().order_in_layer, 2);
+
+	EXPECT_EQ(sorted_sprites[2].get().sorting_in_layer, 2);
+	EXPECT_EQ(sorted_sprites[2].get().order_in_layer, 1);
+
+	EXPECT_EQ(sorted_sprites[3].get().sorting_in_layer, 5);
+	EXPECT_EQ(sorted_sprites[3].get().order_in_layer, 5);
+
+	for (size_t i = 1; i < sorted_sprites.size(); ++i) {
+		const Sprite & prev = sorted_sprites[i - 1].get();
+		const Sprite & curr = sorted_sprites[i].get();
+
+		if (prev.sorting_in_layer == curr.sorting_in_layer) {
+			EXPECT_LE(prev.order_in_layer, curr.order_in_layer);
+		} else {
+			EXPECT_LE(prev.sorting_in_layer, curr.sorting_in_layer);
+		}
+	}
+}
+
+TEST_F(RenderSystemTest, Update) {
+	entity1.add_component<Camera>(Color::WHITE);
+	{
+		vector<reference_wrapper<Sprite>> sprites = this->mgr.get_components_by_type<Sprite>();
+		ASSERT_EQ(sprites.size(), 4);
+
+		EXPECT_EQ(sprites[0].get().game_object_id, 0);
+		EXPECT_EQ(sprites[1].get().game_object_id, 1);
+		EXPECT_EQ(sprites[2].get().game_object_id, 2);
+		EXPECT_EQ(sprites[3].get().game_object_id, 3);
+	}
+	this->sys.update();
+	{
+		vector<reference_wrapper<Sprite>> sprites = this->mgr.get_components_by_type<Sprite>();
+		ASSERT_EQ(sprites.size(), 4);
+
+		EXPECT_EQ(sprites[0].get().game_object_id, 0);
+		EXPECT_EQ(sprites[1].get().game_object_id, 1);
+		EXPECT_EQ(sprites[2].get().game_object_id, 2);
+		EXPECT_EQ(sprites[3].get().game_object_id, 3);
+	}
+}
+
+TEST_F(RenderSystemTest, Camera) {
+	{
+		auto cameras = this->mgr.get_components_by_type<Camera>();
+		EXPECT_NE(cameras.size(), 1);
+	}
+	{
+		entity1.add_component<Camera>(Color::WHITE);
+		auto cameras = this->mgr.get_components_by_type<Camera>();
+		EXPECT_EQ(cameras.size(), 1);
+	}
+
+	//TODO improve with newer version
+}
+TEST_F(RenderSystemTest, Color) {
+	entity1.add_component<Camera>(Color::WHITE);
+	auto & sprite = this->mgr.get_components_by_id<Sprite>(entity1.id).front().get();
+	ASSERT_NE(sprite.sprite_image.get(), nullptr);
+
+	sprite.color = Color::GREEN;
+	EXPECT_EQ(sprite.color.r, Color::GREEN.r);
+	EXPECT_EQ(sprite.color.g, Color::GREEN.g);
+	EXPECT_EQ(sprite.color.b, Color::GREEN.b);
+	EXPECT_EQ(sprite.color.a, Color::GREEN.a);
+	this->sys.update();
+	EXPECT_EQ(sprite.color.r, Color::GREEN.r);
+	EXPECT_EQ(sprite.color.g, Color::GREEN.g);
+	EXPECT_EQ(sprite.color.b, Color::GREEN.b);
+	EXPECT_EQ(sprite.color.a, Color::GREEN.a);
+}