diff --git a/src/main.cpp b/src/main.cpp
index b00fc75..0e66176 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -14,30 +14,13 @@ struct Options {
   std::string deck_file{};
   bool deck_given{false};
   bool help{false};
+  sf::Vector2u pres_size{WINDOW_WIDTH, WINDOW_HEIGHT};
+  sf::Vector2u control_size{CONTROL_WIDTH, CONTROL_HEIGHT};
   bool error{false};
+
   unsigned short port=9898;
 };
 
-std::shared_ptr<SlidesUI> load_slides(const std::string& input_md, std::shared_ptr<gui::Backend> backend) {
-  try {
-    auto deck = parse_slides(input_md, [&](nlohmann::json& config) {
-        backend->set_font(config["font_file"]);
-        guecs::init(backend.get());
-    });
-
-    fmt::println("FONT FILE: {}", backend->$font_file);
-
-    auto slides = std::make_shared<SlidesUI>(deck, sf::Vector2u{WINDOW_WIDTH, WINDOW_HEIGHT});
-    slides->init();
-
-    return slides;
-  } catch(...) {
-    fmt::println("ERROR!");
-    return nullptr;
-  }
-}
-
-
 void print_usage() {
   fmt::println("USAGE: bezos [-p PORT] [-h] -d deck.md");
 }
@@ -73,70 +56,101 @@ Options parse_options(int argc, char* argv[]) {
   return result;
 }
 
+struct App {
+  Options options;
+  gui::Backend backend{};
+  sf::RenderWindow presenter{sf::VideoMode(options.pres_size),
+      "Bezos Loves Slides", sf::Style::None, sf::State::Windowed};
 
-int main(int argc, char *argv[]) {
-  auto options = parse_options(argc, argv);
+  sf::RenderWindow controller{sf::VideoMode(options.control_size), "Bezos Loves Control"};
+  std::shared_ptr<ControlUI> control_ui = nullptr;
+  std::shared_ptr<SlidesUI> slides = nullptr;
+  ChangeDetector reloader{};
 
-  if(options.help) {
-    return 0;
-  } else if(options.error) {
-    return 1;
+  void init() {
+    presenter.setPosition({0,0});
+    presenter.setFramerateLimit(FRAME_LIMIT);
+    presenter.setVerticalSyncEnabled(VSYNC);
+
+    slides = load_slides();
+    dbc::check(slides != nullptr, "ERROR in your .md file");
+
+    control_ui = std::make_shared<ControlUI>(presenter, controller, options.port);
+    control_ui->init();
+    control_ui->full_screen(false);
+
+    reloader.watch(options.deck_file);
+    reloader.watch(slides->$deck->config["layouts"]);
   }
 
-  auto& modes = sf::VideoMode::getFullscreenModes();
-  auto screen_mode = std::find_if(modes.begin(), modes.end(), [=](const auto& a) -> bool {
-      return a.size.x == WINDOW_WIDTH && a.size.y == WINDOW_HEIGHT;
-  });
+  void change_slides() {
+    // save the current slide
+    auto current_slide = slides->$deck->current;
+    // load the new one
+    auto new_slides = load_slides();
 
-  sf::RenderWindow presenter(*screen_mode,
-      "Bezos Loves Slides", sf::Style::None, sf::State::Windowed);
+    if(new_slides) {
+      new_slides->set_slide(current_slide);
+      slides = new_slides;
+    }
+  }
 
-  presenter.setPosition({0,0});
-  presenter.setFramerateLimit(FRAME_LIMIT);
-  presenter.setVerticalSyncEnabled(VSYNC);
+  void update() {
+    if(reloader.changed()) {
+      change_slides();
+    }
 
-  sf::RenderWindow controller(sf::VideoMode({CONTROL_WIDTH, CONTROL_HEIGHT}), "Bezos Loves Control");
+    slides->update(presenter);
+    control_ui->update(slides);
+  }
 
-  auto backend = std::make_shared<gui::Backend>();
+  void render() {
+    slides->render(presenter);
+    control_ui->render(controller, *slides->$deck);
 
-  auto slides = load_slides(options.deck_file, backend);
+    presenter.display();
+    controller.display();
+  }
 
-  if(!slides) {
-    fmt::println("ERROR in your .md file");
-    return 1;
+  bool open() {
+    return controller.isOpen();
   }
 
-  ControlUI control_ui{presenter, controller, options.port};
-  control_ui.init();
-  control_ui.full_screen(false);
+  std::shared_ptr<SlidesUI> load_slides() {
+    try {
+      auto deck = parse_slides(options.deck_file, [&](nlohmann::json& config) {
+          backend.set_font(config["font_file"]);
+          guecs::init(&backend);
+      });
+
+      fmt::println("FONT FILE: {}", backend.$font_file);
 
-  ChangeDetector reloader;
-  reloader.watch(options.deck_file);
-  reloader.watch(slides->$deck->config["layouts"]);
+      auto slides = std::make_shared<SlidesUI>(deck, options.pres_size);
+      slides->init();
 
-  while(controller.isOpen()) {
-    while(const auto event = presenter.pollEvent()) {
-      if(event) slides->handle_events(presenter, *event);
+      return slides;
+    } catch(...) {
+      fmt::println("ERROR!");
+      return nullptr;
     }
+  }
+};
 
-    control_ui.update(slides);
+int main(int argc, char *argv[]) {
+  auto options = parse_options(argc, argv);
 
-    slides->render(presenter);
-    control_ui.render(controller, *slides->$deck);
+  if(options.help) {
+    return 0;
+  } else if(options.error) {
+    return 1;
+  }
 
-    presenter.display();
-    controller.display();
+  auto app = std::make_shared<App>(options);
 
-    if(reloader.changed()) {
-      // save the current slide
-      auto current_slide = slides->$deck->current;
-      // load the new one
-      auto new_slides = load_slides(options.deck_file, backend);
-
-      if(new_slides) {
-        new_slides->set_slide(current_slide);
-        slides = new_slides;
-      }
-    }
+  app->init();
+
+  while(app->open()) {
+    app->update();
+    app->render();
   }
 }
diff --git a/src/slides_ui.cpp b/src/slides_ui.cpp
index 3562641..811936e 100644
--- a/src/slides_ui.cpp
+++ b/src/slides_ui.cpp
@@ -238,6 +238,12 @@ void SlidesUI::mouse(float x, float y, guecs::Modifiers mods) {
   }
 }
 
+void SlidesUI::update(sf::RenderWindow& presenter) {
+  while(const auto event = presenter.pollEvent()) {
+    if(event) handle_events(presenter, *event);
+  }
+}
+
 void SlidesUI::handle_events(sf::RenderWindow& presenter, const sf::Event& event) {
   if(const auto* mev = event.getIf<sf::Event::MouseButtonPressed>()) {
     sf::Vector2f pos = presenter.mapPixelToCoords(mev->position);
diff --git a/src/slides_ui.hpp b/src/slides_ui.hpp
index ba3127f..f1150bb 100644
--- a/src/slides_ui.hpp
+++ b/src/slides_ui.hpp
@@ -63,6 +63,7 @@ struct SlidesUI {
   void render(sf::RenderTarget& window);
   void mouse(float x, float y, guecs::Modifiers mods);
   void set_text(const std::string& name);
+  void update(sf::RenderWindow& presenter);
   void handle_events(sf::RenderWindow& presenter, const sf::Event& event);
   void configure_layouts();
 };