12 files changed, 336 insertions, 0 deletions

diff --git a/src/crepe/system/CMakeLists.txt b/src/crepe/system/CMakeLists.txt
new file mode 100644
index 0000000..ff6f66f
--- /dev/null
+++ b/src/crepe/system/CMakeLists.txt
@@ -0,0 +1,15 @@
+target_sources(crepe PUBLIC
+	ParticleSystem.cpp
+	ScriptSystem.cpp
+	PhysicsSystem.cpp
+	CollisionSystem.cpp
+	RenderSystem.cpp
+)
+
+target_sources(crepe PUBLIC FILE_SET HEADERS FILES
+	System.h
+	ScriptSystem.h
+	PhysicsSystem.h
+	CollisionSystem.h
+	RenderSystem.h
+)
diff --git a/src/crepe/system/CollisionSystem.cpp b/src/crepe/system/CollisionSystem.cpp
new file mode 100644
index 0000000..55e0fdc
--- /dev/null
+++ b/src/crepe/system/CollisionSystem.cpp
@@ -0,0 +1,7 @@
+#include "CollisionSystem.h"
+
+using namespace crepe;
+
+CollisionSystem::CollisionSystem() {}
+
+void CollisionSystem::update() {}
diff --git a/src/crepe/system/CollisionSystem.h b/src/crepe/system/CollisionSystem.h
new file mode 100644
index 0000000..1e9f1aa
--- /dev/null
+++ b/src/crepe/system/CollisionSystem.h
@@ -0,0 +1,11 @@
+#pragma once
+
+namespace crepe {
+
+class CollisionSystem {
+public:
+	CollisionSystem();
+	void update();
+};
+
+} // namespace crepe
diff --git a/src/crepe/system/ParticleSystem.cpp b/src/crepe/system/ParticleSystem.cpp
new file mode 100644
index 0000000..397b586
--- /dev/null
+++ b/src/crepe/system/ParticleSystem.cpp
@@ -0,0 +1,62 @@
+#include <cmath>
+#include <ctime>
+
+#include "../ComponentManager.h"
+#include "../api/ParticleEmitter.h"
+
+#include "ParticleSystem.h"
+
+using namespace crepe;
+
+ParticleSystem::ParticleSystem() : elapsed_time(0.0f) {}
+
+void ParticleSystem::update() {
+	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);
+		}
+		for (size_t j = 0; j < emitter.particles.size(); j++) {
+			if (emitter.particles[j].active) {
+				emitter.particles[j].update(delta_time);
+			}
+		}
+	}
+}
+
+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);
+			break;
+		}
+	}
+}
diff --git a/src/crepe/system/ParticleSystem.h b/src/crepe/system/ParticleSystem.h
new file mode 100644
index 0000000..3ac1d3f
--- /dev/null
+++ b/src/crepe/system/ParticleSystem.h
@@ -0,0 +1,18 @@
+#pragma once
+
+#include "../api/ParticleEmitter.h"
+
+namespace crepe {
+
+class ParticleSystem {
+public:
+	ParticleSystem();
+	void update();
+
+private:
+	void emit_particle(ParticleEmitter & emitter); //emits a new particle
+
+	float elapsed_time; //elapsed time since the last emission
+};
+
+} // namespace crepe
diff --git a/src/crepe/system/PhysicsSystem.cpp b/src/crepe/system/PhysicsSystem.cpp
new file mode 100644
index 0000000..cea8062
--- /dev/null
+++ b/src/crepe/system/PhysicsSystem.cpp
@@ -0,0 +1,61 @@
+#include <iostream>
+
+#include "../ComponentManager.h"
+#include "../api/Force.h"
+#include "../api/Rigidbody.h"
+#include "../api/Transform.h"
+
+#include "PhysicsSystem.h"
+
+using namespace crepe;
+
+PhysicsSystem::PhysicsSystem() {}
+
+void PhysicsSystem::update() {
+	ComponentManager & mgr = ComponentManager::get_instance();
+	std::vector<std::reference_wrapper<Rigidbody>> rigidbodies
+		= mgr.get_components_by_type<Rigidbody>();
+	std::vector<std::reference_wrapper<Transform>> transforms
+		= mgr.get_components_by_type<Transform>();
+
+	for (Rigidbody & rigidbody : rigidbodies) {
+
+		switch (rigidbody.body_type) {
+			case BodyType::DYNAMIC:
+				for (Transform & transform : transforms) {
+					if (transform.game_object_id == rigidbody.game_object_id) {
+						rigidbody.velocity_x = 0;
+						rigidbody.velocity_y = 0;
+						std::vector<std::reference_wrapper<Force>> forces
+							= mgr.get_components_by_id<Force>(
+								rigidbody.game_object_id);
+						rigidbody.velocity_y
+							+= rigidbody.gravity_scale * 1 * rigidbody.mass;
+
+						for (Force & force : forces) {
+							rigidbody.velocity_x += force.force_x;
+							rigidbody.velocity_y += force.force_y;
+						}
+
+						std::cout << "before transform.postion.x "
+								  << transform.position.x << std::endl;
+						std::cout << "before transform.postion.y "
+								  << transform.position.y << std::endl;
+						transform.position.x += rigidbody.velocity_x;
+						transform.position.y += rigidbody.velocity_y;
+						std::cout << "after transform.postion.x "
+								  << transform.position.x << std::endl;
+						std::cout << "after transform.postion.y "
+								  << transform.position.y << std::endl;
+					}
+				}
+				break;
+			case BodyType::KINEMATIC:
+				break; //(scripts)
+			case BodyType::STATIC:
+				break; //(unmoveable objects)
+			default:
+				break;
+		}
+	}
+}
diff --git a/src/crepe/system/PhysicsSystem.h b/src/crepe/system/PhysicsSystem.h
new file mode 100644
index 0000000..33b4072
--- /dev/null
+++ b/src/crepe/system/PhysicsSystem.h
@@ -0,0 +1,11 @@
+#pragma once
+
+namespace crepe {
+
+class PhysicsSystem {
+public:
+	PhysicsSystem();
+	void update();
+};
+
+} // namespace crepe
diff --git a/src/crepe/system/RenderSystem.cpp b/src/crepe/system/RenderSystem.cpp
new file mode 100644
index 0000000..96c94e9
--- /dev/null
+++ b/src/crepe/system/RenderSystem.cpp
@@ -0,0 +1,41 @@
+#include <functional>
+#include <vector>
+
+#include "../ComponentManager.h"
+#include "../facade/SDLContext.h"
+#include "../api/Sprite.h"
+#include "../api/Transform.h"
+#include "../util/log.h"
+
+#include "RenderSystem.h"
+
+using namespace crepe;
+
+RenderSystem::RenderSystem() { dbg_trace(); }
+
+RenderSystem::~RenderSystem() { dbg_trace(); }
+
+RenderSystem & RenderSystem::get_instance() {
+	static RenderSystem instance;
+	return instance;
+}
+
+void RenderSystem::update() {
+
+	ComponentManager & mgr = ComponentManager::get_instance();
+
+	std::vector<std::reference_wrapper<Sprite>> sprites
+		= mgr.get_components_by_type<Sprite>();
+
+	SDLContext & render = SDLContext::get_instance();
+	render.clear_screen();
+
+	for (const Sprite & sprite : sprites) {
+		std::vector<std::reference_wrapper<Transform>> transforms
+			= mgr.get_components_by_id<Transform>(sprite.game_object_id);
+		for (const Transform & transform : transforms) {
+			render.draw(sprite, transform);
+		}
+	}
+	render.present_screen();
+}
diff --git a/src/crepe/system/RenderSystem.h b/src/crepe/system/RenderSystem.h
new file mode 100644
index 0000000..4b910a4
--- /dev/null
+++ b/src/crepe/system/RenderSystem.h
@@ -0,0 +1,17 @@
+#pragma once
+
+#include "System.h"
+
+namespace crepe {
+
+class RenderSystem : public System {
+
+public:
+	static RenderSystem & get_instance();
+	void update();
+
+private:
+	RenderSystem();
+	~RenderSystem();
+};
+} // namespace crepe
diff --git a/src/crepe/system/ScriptSystem.cpp b/src/crepe/system/ScriptSystem.cpp
new file mode 100644
index 0000000..f1fae4d
--- /dev/null
+++ b/src/crepe/system/ScriptSystem.cpp
@@ -0,0 +1,46 @@
+#include <forward_list>
+#include <functional>
+#include <vector>
+
+#include "../ComponentManager.h"
+#include "../api/BehaviorScript.h"
+#include "../api/Script.h"
+#include "../util/log.h"
+
+#include "ScriptSystem.h"
+
+using namespace std;
+using namespace crepe;
+
+ScriptSystem::ScriptSystem() { dbg_trace(); }
+ScriptSystem::~ScriptSystem() { dbg_trace(); }
+
+ScriptSystem & ScriptSystem::get_instance() {
+	static ScriptSystem instance;
+	return instance;
+}
+
+void ScriptSystem::update() {
+	using namespace std;
+	dbg_trace();
+
+	forward_list<Script *> scripts = this->get_scripts();
+	for (Script * script : scripts) script->update();
+}
+
+forward_list<Script *> ScriptSystem::get_scripts() {
+	forward_list<Script *> scripts = {};
+	ComponentManager & mgr = ComponentManager::get_instance();
+	vector<reference_wrapper<BehaviorScript>> behavior_scripts
+		= mgr.get_components_by_type<BehaviorScript>();
+
+	for (auto behavior_script_ref : behavior_scripts) {
+		BehaviorScript & behavior_script = behavior_script_ref.get();
+		if (!behavior_script.active) continue;
+		Script * script = behavior_script.script.get();
+		if (script == nullptr) continue;
+		scripts.push_front(script);
+	}
+
+	return scripts;
+}
diff --git a/src/crepe/system/ScriptSystem.h b/src/crepe/system/ScriptSystem.h
new file mode 100644
index 0000000..32e793c
--- /dev/null
+++ b/src/crepe/system/ScriptSystem.h
@@ -0,0 +1,25 @@
+#pragma once
+
+#include <forward_list>
+
+#include "System.h"
+
+namespace crepe {
+
+class Script;
+
+class ScriptSystem : public System {
+public:
+	static ScriptSystem & get_instance();
+	void update();
+
+private:
+	ScriptSystem();
+	~ScriptSystem();
+
+private:
+	// TODO: to forward_list<reference_wrapper>
+	std::forward_list<Script *> get_scripts();
+};
+
+} // namespace crepe
diff --git a/src/crepe/system/System.h b/src/crepe/system/System.h
new file mode 100644
index 0000000..ecbb7f5
--- /dev/null
+++ b/src/crepe/system/System.h
@@ -0,0 +1,22 @@
+#pragma once
+
+namespace crepe {
+
+class System {
+public:
+	static System & get_instance();
+	virtual void update() = 0;
+
+protected:
+	System() {};
+	virtual ~System() {};
+
+private:
+	// singleton
+	System(const System &) = delete;
+	System(System &&) = delete;
+	System & operator=(const System &) = delete;
+	System & operator=(System &&) = delete;
+};
+
+} // namespace crepe