diff --git a/include/app/app.h b/include/app/app.h
index d1be796..5692f66 100644
--- a/include/app/app.h
+++ b/include/app/app.h
@@ -6,8 +6,13 @@
 #include "utils.h"
 #include "window/window.h"
 
+enum Type { IMAGE,
+            TEXT,
+            RECT };
+
 namespace app {
 struct Element {
+  Type type;
   Vec2<float> position = {0, 0};
   float rotation = 0;
   Vec2<float> scale = {1, 1};
@@ -15,6 +20,7 @@ struct Element {
   bool click_through = false;
   Ruby::Block on_click;
 
+  Element(Type type) : type(type) {}
   virtual ~Element() = default;
   virtual void render(Window &window, uint64_t abs_time) = 0;
   virtual Vec2<float> size(Window *window) = 0;
@@ -26,14 +32,14 @@ struct Element {
 };
 
 struct EImage : Element {
-  int animation_id = -1;
+  uint64_t animation_id = UINT64_MAX;
 
-  EImage(int animation_id) : animation_id(animation_id) {
+  EImage(uint64_t animation_id) : Element(Type::IMAGE), animation_id(animation_id) {
     animation_pool.use(animation_id);
   }
 
   ~EImage() {
-    if (animation_id != -1)
+    if (animation_id != UINT64_MAX)
       animation_pool.release(animation_id);
   }
 
@@ -56,30 +62,32 @@ struct EImage : Element {
 
 struct EText : Element {
   Localization::Key key;
-  int font_id = -1;
+  uint64_t font_id = UINT64_MAX;
 
   ~EText() {
-    if (text_id != -1)
+    if (text_id != UINT64_MAX)
       text_pool.release(text_id);
-    if (font_id != -1)
+    if (font_id != UINT64_MAX)
       font_pool.release(font_id);
   }
 
   Color color = {255, 255, 255, 255};
 
-  EText(Localization::Key key, int font_id, Color color)
-      : key(key), font_id(font_id), color(color) {
+  EText(Localization::Key key, uint64_t font_id, Color color)
+      : Element(Type::TEXT), key(key), font_id(font_id), color(color) {
     font_pool.use(font_id);
   }
 
   Vec2<float> size(Window *window) override {
+    if (text_id == UINT64_MAX)
+      return {0, 0};
     return window->get_text_size(text_id);
   };
 
   void render(Window &window, uint64_t) override {
-    if (last_language != Localization::current_language || last_key != key || text_id == -1) {
+    if (last_language != Localization::current_language || last_key != key || text_id == UINT64_MAX) {
       std::string localized_str = Localization::get(key);
-      if (text_id != -1)
+      if (text_id != UINT64_MAX)
         text_pool.release(text_id);
       text_id = window.create_text(font_id, localized_str.c_str(), localized_str.size(), color);
       last_language = Localization::current_language;
@@ -89,9 +97,9 @@ struct EText : Element {
   }
 
 private:
-  int text_id = -1;
-  Localization::LanguageCode last_language = -1;
-  Localization::Key last_key = -1;
+  uint64_t text_id = UINT64_MAX;
+  Localization::LanguageCode last_language = UINT_MAX;
+  Localization::Key last_key = UINT_MAX;
 };
 
 struct ERect : Element {
@@ -101,7 +109,7 @@ struct ERect : Element {
     return shape;
   };
 
-  ERect(Vec2<float> shape, Color color) : shape(shape), color(color) {}
+  ERect(Vec2<float> shape, Color color) : Element(Type::RECT), shape(shape), color(color) {}
 
   void render(Window &window, uint64_t) override {
     window.draw_rect(Rect::from_size(position, shape), color, z, rotation);
@@ -111,15 +119,15 @@ struct ERect : Element {
 inline Pool<Element> element_pool;
 
 struct Scene {
-  std::vector<int> element_ids;
+  std::vector<uint64_t> element_ids;
   Ruby::Block update;
 
   ~Scene() {
-    for (const int &id : element_ids)
+    for (const uint64_t &id : element_ids)
       element_pool.release(id);
   }
 
-  void add_element(int element_id) {
+  void add_element(uint64_t element_id) {
     auto it = std::lower_bound(
       element_ids.begin(),
       element_ids.end(),
@@ -134,7 +142,7 @@ struct Scene {
     element_ids.insert(it, element_id);
   }
 
-  void delete_element(int element_id) {
+  void delete_element(uint64_t element_id) {
     auto it = std::find(element_ids.begin(), element_ids.end(), element_id);
     if (it != element_ids.end()) {
       element_pool.release(element_id);
@@ -149,23 +157,33 @@ struct Scene {
     }
   }
 
-  void click(Window *window, Vec2<float> position) {
+  void click(Vec2<float> position) {
+    std::vector<uint64_t> clicked_elements = elements_at(position);
+    for (const uint64_t &id : clicked_elements)
+      element_pool[id]->click();
+  }
+
+  std::vector<uint64_t> elements_at(Vec2<float> position) {
+    std::vector<uint64_t> result;
+
     for (auto it = element_ids.rbegin(); it != element_ids.rend(); ++it) {
       Element *e = element_pool[*it];
-      Vec2<float> size = e->size(window);
+      Vec2<float> size = e->size(&window);
       Rect rect = Rect::from_size(e->position, size * e->scale);
       if (rect.contains(position)) {
-        e->click();
+        result.push_back(*it);
         if (e->click_through)
           continue;
         else
           break;
       }
     }
+
+    return result;
   }
 
   void render(Window &window, uint64_t abs_time) {
-    for (const int &e : element_ids)
+    for (const uint64_t &e : element_ids)
       element_pool[e]->render(window, abs_time);
   }
 };
@@ -173,10 +191,11 @@ struct Scene {
 inline Pool<Scene> scene_pool;
 
 struct App {
-  int current_scene_id = 0;
+  uint64_t current_scene_id = 0;
   bool running = true;
+  Vec2<float> mouse_position = {-1, -1};
 
-  void switch_to_scene(int scene_id) {
+  void switch_to_scene(uint64_t scene_id) {
     scene_pool.release(current_scene_id);
     scene_pool.use(scene_id);
     current_scene_id = scene_id;
@@ -213,7 +232,13 @@ struct App {
           running = false;
           break;
         case Event::MOUSE_BUTTON_DOWN:
-          scene->click(&window, e.mouse_button.position);
+          scene->click(e.mouse_button.position);
+          break;
+        case Event::MOUSE_MOVE:
+          mouse_position = e.mouse_move.position;
+          break;
+        case Event::MOUSE_LEAVE:
+          mouse_position = {-1, -1};
           break;
         default:
           break;
diff --git a/include/binding/definitions.h b/include/binding/definitions.h
index 9e3155d..4504cf1 100644
--- a/include/binding/definitions.h
+++ b/include/binding/definitions.h
@@ -4,10 +4,9 @@
 #include "app/app.h"
 
 #warning "Define ==, eql?, hash for each class"
-#warning "Define and bind elements_at in Scene (same as click method already defined but without callback)"
 
 namespace definitions {
-inline mrb_value wrap(mrb_state *mrb, RClass *cls, mrb_data_type *type, int id) {
+inline mrb_value wrap(mrb_state *mrb, RClass *cls, const mrb_data_type *type, uint64_t id) {
   RBasic *obj_b = mrb_obj_alloc(mrb, MRB_TT_DATA, cls);
   mrb_value obj = mrb_obj_value(obj_b);
 
@@ -21,7 +20,7 @@ inline mrb_value wrap(mrb_state *mrb, RClass *cls, mrb_data_type *type, int id)
 
 static void Font_free(mrb_state *mrb, void *ptr) {
   UNUSED(mrb);
-  int id = ((Wrapper *)ptr)->id;
+  uint64_t id = ((Wrapper *)ptr)->id;
   font_pool.release(id);
   delete (Wrapper *)ptr;
 }
@@ -58,7 +57,7 @@ static mrb_value Font_init(mrb_state *mrb, mrb_value self) {
   return self;
 }
 
-inline int get_id_Font(mrb_state *mrb, mrb_value self) {
+inline uint64_t get_id_Font(mrb_state *mrb, mrb_value self) {
   Wrapper *wrapper;
   Data_Get_Struct(mrb, self, &Font_type, wrapper);
   return wrapper->id;
@@ -66,7 +65,7 @@ inline int get_id_Font(mrb_state *mrb, mrb_value self) {
 
 static void Image_free(mrb_state *mrb, void *ptr) {
   UNUSED(mrb);
-  int id = ((Wrapper *)ptr)->id;
+  uint64_t id = ((Wrapper *)ptr)->id;
   image_pool.release(id);
   delete (Wrapper *)ptr;
 }
@@ -98,7 +97,7 @@ static mrb_value Image_init(mrb_state *mrb, mrb_value self) {
   return self;
 }
 
-inline int get_id_Image(mrb_state *mrb, mrb_value self) {
+inline uint64_t get_id_Image(mrb_state *mrb, mrb_value self) {
   Wrapper *wrapper;
   Data_Get_Struct(mrb, self, &Image_type, wrapper);
   return wrapper->id;
@@ -106,7 +105,7 @@ inline int get_id_Image(mrb_state *mrb, mrb_value self) {
 
 static void Animation_free(mrb_state *mrb, void *ptr) {
   UNUSED(mrb);
-  int id = ((Wrapper *)ptr)->id;
+  uint64_t id = ((Wrapper *)ptr)->id;
   animation_pool.release(id);
   delete (Wrapper *)ptr;
 }
@@ -132,7 +131,7 @@ static mrb_value Animation_init(mrb_state *mrb, mrb_value self) {
   if (!mrb_nil_p(kwargs))
     HASH_FLOAT(kwargs, fps, fps);
 
-  std::vector<int> frame_ids;
+  std::vector<uint64_t> frame_ids;
   for (mrb_int i = 0; i < frames_len; i++) {
     mrb_value frame_val = frames_val[i];
     if (!mrb_obj_is_kind_of(mrb, frame_val, mrb_class_get(mrb, "Image"))) {
@@ -143,7 +142,7 @@ static mrb_value Animation_init(mrb_state *mrb, mrb_value self) {
       );
       return mrb_nil_value();
     }
-    int frame_id = get_id_Image(mrb, frame_val);
+    uint64_t frame_id = get_id_Image(mrb, frame_val);
     image_pool.use(frame_id);
     frame_ids.push_back(frame_id);
   }
@@ -156,7 +155,7 @@ static mrb_value Animation_init(mrb_state *mrb, mrb_value self) {
   return self;
 }
 
-inline int get_id_Animation(mrb_state *mrb, mrb_value self) {
+inline uint64_t get_id_Animation(mrb_state *mrb, mrb_value self) {
   Wrapper *wrapper;
   Data_Get_Struct(mrb, self, &Animation_type, wrapper);
   return wrapper->id;
@@ -164,7 +163,7 @@ inline int get_id_Animation(mrb_state *mrb, mrb_value self) {
 
 static void ElementText_free(mrb_state *mrb, void *ptr) {
   UNUSED(mrb);
-  int id = ((Wrapper *)ptr)->id;
+  uint64_t id = ((Wrapper *)ptr)->id;
   app::element_pool.release(id);
   delete (Wrapper *)ptr;
 }
@@ -208,7 +207,7 @@ static mrb_value ElementText_init(mrb_state *mrb, mrb_value self) {
 
   Vec2<float> position = {x, y};
 
-  int id = get_id_Font(mrb, font_val);
+  uint64_t id = get_id_Font(mrb, font_val);
   font_pool.use(id);
 
   app::EText *element = new app::EText(key_id, id, {255, 255, 255, 255});
@@ -223,7 +222,7 @@ static mrb_value ElementText_init(mrb_state *mrb, mrb_value self) {
   return self;
 }
 
-inline int get_id_ElementText(mrb_state *mrb, mrb_value self) {
+inline uint64_t get_id_ElementText(mrb_state *mrb, mrb_value self) {
   Wrapper *wrapper;
   Data_Get_Struct(mrb, self, &ElementText_type, wrapper);
   return wrapper->id;
@@ -232,7 +231,7 @@ inline int get_id_ElementText(mrb_state *mrb, mrb_value self) {
 static mrb_value element_text_on_click(mrb_state *mrb, mrb_value self) {
   mrb_value block;
   mrb_get_args(mrb, "&", &block);
-  int id = get_id_ElementText(mrb, self);
+  uint64_t id = get_id_ElementText(mrb, self);
   app::Element *element = app::element_pool[id];
   element->on_click.set_proc(block);
   return self;
@@ -240,7 +239,7 @@ static mrb_value element_text_on_click(mrb_state *mrb, mrb_value self) {
 
 static void ElementRect_free(mrb_state *mrb, void *ptr) {
   UNUSED(mrb);
-  int id = ((Wrapper *)ptr)->id;
+  uint64_t id = ((Wrapper *)ptr)->id;
   app::element_pool.release(id);
   delete (Wrapper *)ptr;
 }
@@ -271,8 +270,11 @@ static mrb_value ElementRect_init(mrb_state *mrb, mrb_value self) {
   }
 
   float z = 0;
-  if (!mrb_nil_p(kwargs))
+  bool click_through = false;
+  if (!mrb_nil_p(kwargs)) {
     HASH_FLOAT(kwargs, z, z);
+    HASH_BOOL(kwargs, click_through, click_through);
+  }
 
   Vec2<float> position = {x, y};
   Vec2<float> shape = {w, h};
@@ -286,6 +288,7 @@ static mrb_value ElementRect_init(mrb_state *mrb, mrb_value self) {
   );
   element->position = position;
   element->z = z;
+  element->click_through = click_through;
 
   s->id = app::element_pool.acquire(element);
   app::element_pool.use(s->id);
@@ -294,7 +297,7 @@ static mrb_value ElementRect_init(mrb_state *mrb, mrb_value self) {
   return self;
 }
 
-inline int get_id_ElementRect(mrb_state *mrb, mrb_value self) {
+inline uint64_t get_id_ElementRect(mrb_state *mrb, mrb_value self) {
   Wrapper *wrapper;
   Data_Get_Struct(mrb, self, &ElementRect_type, wrapper);
   return wrapper->id;
@@ -303,7 +306,7 @@ inline int get_id_ElementRect(mrb_state *mrb, mrb_value self) {
 static mrb_value element_rect_on_click(mrb_state *mrb, mrb_value self) {
   mrb_value block;
   mrb_get_args(mrb, "&", &block);
-  int id = get_id_ElementRect(mrb, self);
+  uint64_t id = get_id_ElementRect(mrb, self);
   app::Element *element = app::element_pool[id];
   element->on_click.set_proc(block);
   return self;
@@ -312,7 +315,7 @@ static mrb_value element_rect_on_click(mrb_state *mrb, mrb_value self) {
 static mrb_value element_rect_color_set(mrb_state *mrb, mrb_value self) {
   mrb_value color_val;
   mrb_get_args(mrb, "o", &color_val);
-  int id = get_id_ElementRect(mrb, self);
+  uint64_t id = get_id_ElementRect(mrb, self);
   app::ERect *element = (app::ERect *)app::element_pool[id];
   element->color = {
     (uint8_t)((mrb_fixnum(color_val) >> 24) & 0xFF),
@@ -324,7 +327,7 @@ static mrb_value element_rect_color_set(mrb_state *mrb, mrb_value self) {
 }
 
 static mrb_value element_rect_color_get(mrb_state *mrb, mrb_value self) {
-  int id = get_id_ElementRect(mrb, self);
+  uint64_t id = get_id_ElementRect(mrb, self);
   app::ERect *element = (app::ERect *)app::element_pool[id];
   uint32_t color =
     ((uint32_t)element->color.r << 24) | ((uint32_t)element->color.g << 16)
@@ -334,7 +337,7 @@ static mrb_value element_rect_color_get(mrb_state *mrb, mrb_value self) {
 
 static void ElementImage_free(mrb_state *mrb, void *ptr) {
   UNUSED(mrb);
-  int id = ((Wrapper *)ptr)->id;
+  uint64_t id = ((Wrapper *)ptr)->id;
   app::element_pool.release(id);
   delete (Wrapper *)ptr;
 }
@@ -380,7 +383,7 @@ static mrb_value ElementImage_init(mrb_state *mrb, mrb_value self) {
     HASH_BOOL(kwargs, click_through, click_through);
   }
 
-  int id = get_id_Animation(mrb, animation_val);
+  uint64_t id = get_id_Animation(mrb, animation_val);
 
   app::EImage *element = new app::EImage(id);
   element->position = {x, y};
@@ -394,7 +397,7 @@ static mrb_value ElementImage_init(mrb_state *mrb, mrb_value self) {
   return self;
 }
 
-inline int get_id_ElementImage(mrb_state *mrb, mrb_value self) {
+inline uint64_t get_id_ElementImage(mrb_state *mrb, mrb_value self) {
   Wrapper *wrapper;
   Data_Get_Struct(mrb, self, &ElementImage_type, wrapper);
   return wrapper->id;
@@ -403,7 +406,7 @@ inline int get_id_ElementImage(mrb_state *mrb, mrb_value self) {
 static mrb_value element_image_on_click(mrb_state *mrb, mrb_value self) {
   mrb_value block;
   mrb_get_args(mrb, "&", &block);
-  int id = get_id_ElementImage(mrb, self);
+  uint64_t id = get_id_ElementImage(mrb, self);
   app::Element *element = app::element_pool[id];
   element->on_click.set_proc(block);
   return self;
@@ -411,7 +414,7 @@ static mrb_value element_image_on_click(mrb_state *mrb, mrb_value self) {
 
 static void Scene_free(mrb_state *mrb, void *ptr) {
   UNUSED(mrb);
-  int id = ((Wrapper *)ptr)->id;
+  uint64_t id = ((Wrapper *)ptr)->id;
   app::scene_pool.release(id);
   delete (Wrapper *)ptr;
 }
@@ -434,7 +437,7 @@ static mrb_value Scene_init(mrb_state *mrb, mrb_value self) {
   return self;
 }
 
-inline int get_id_Scene(mrb_state *mrb, mrb_value self) {
+inline uint64_t get_id_Scene(mrb_state *mrb, mrb_value self) {
   Wrapper *wrapper;
   Data_Get_Struct(mrb, self, &Scene_type, wrapper);
   return wrapper->id;
@@ -457,10 +460,10 @@ static mrb_value scene_add_element(mrb_state *mrb, mrb_value self) {
     return mrb_nil_value();
   }
 
-  int id = get_id_Scene(mrb, self);
+  uint64_t id = get_id_Scene(mrb, self);
   app::Scene *scene = app::scene_pool[id];
 
-  int element_id;
+  uint64_t element_id;
   if (mrb_obj_is_kind_of(mrb, element_val, mrb_class_get(mrb, "ElementText"))) {
     element_id = get_id_ElementText(mrb, element_val);
   } else if (
@@ -502,10 +505,10 @@ static mrb_value scene_delete_element(mrb_state *mrb, mrb_value self) {
     return mrb_nil_value();
   }
 
-  int id = get_id_Scene(mrb, self);
+  uint64_t id = get_id_Scene(mrb, self);
   app::Scene *scene = app::scene_pool[id];
 
-  int element_id;
+  uint64_t element_id;
   if (mrb_obj_is_kind_of(mrb, element_val, mrb_class_get(mrb, "ElementText"))) {
     element_id = get_id_ElementText(mrb, element_val);
   } else if (
@@ -534,13 +537,50 @@ static mrb_value scene_on_update(mrb_state *mrb, mrb_value self) {
   mrb_value block;
   mrb_get_args(mrb, "&", &block);
 
-  int id = get_id_Scene(mrb, self);
+  uint64_t id = get_id_Scene(mrb, self);
   app::Scene *scene = app::scene_pool[id];
   scene->update.set_proc(block);
 
   return self;
 }
 
+static mrb_value scene_elements_at(mrb_state *mrb, mrb_value self) {
+  mrb_value position_val;
+  mrb_get_args(mrb, "o", &position_val);
+
+  float x, y;
+  HASH_FLOAT(position_val, x, x);
+  HASH_FLOAT(position_val, y, y);
+  Vec2<float> position = {x, y};
+
+  uint64_t id = get_id_Scene(mrb, self);
+  app::Scene *scene = app::scene_pool[id];
+
+  std::vector<uint64_t> element_ids = scene->elements_at(position);
+
+  mrb_value result = mrb_ary_new_capa(mrb, element_ids.size());
+  for (uint64_t element_id : element_ids) {
+    app::Element *element = app::element_pool[element_id];
+    if (element->type == Type::TEXT) {
+      RClass *ElementText_class = mrb_class_get(mrb, "ElementText");
+      mrb_value obj = wrap(mrb, ElementText_class, &ElementText_type, element_id);
+      mrb_ary_push(mrb, result, obj);
+    } else if (element->type == Type::RECT) {
+      RClass *ElementRect_class = mrb_class_get(mrb, "ElementRect");
+      mrb_value obj = wrap(mrb, ElementRect_class, &ElementRect_type, element_id);
+      mrb_ary_push(mrb, result, obj);
+    } else if (element->type == Type::IMAGE) {
+      RClass *ElementImage_class = mrb_class_get(mrb, "ElementImage");
+      mrb_value obj = wrap(mrb, ElementImage_class, &ElementImage_type, element_id);
+      mrb_ary_push(mrb, result, obj);
+    } else {
+      continue;
+    }
+  }
+
+  return result;
+}
+
 static mrb_value app_run(mrb_state *mrb, mrb_value) {
   mrb_int width, height;
   char *title = nullptr;
@@ -560,7 +600,7 @@ static mrb_value app_start(mrb_state *mrb, mrb_value) {
     return mrb_nil_value();
   }
 
-  int id = get_id_Scene(mrb, scene_val);
+  uint64_t id = get_id_Scene(mrb, scene_val);
   app_->switch_to_scene(id);
 
   app_->loop();
@@ -577,7 +617,7 @@ static mrb_value app_switch_to(mrb_state *mrb, mrb_value) {
     return mrb_nil_value();
   }
 
-  int id = get_id_Scene(mrb, scene_val);
+  uint64_t id = get_id_Scene(mrb, scene_val);
   app_->switch_to_scene(id);
 
   return mrb_nil_value();
@@ -615,6 +655,14 @@ static mrb_value app_language_set(mrb_state *mrb, mrb_value) {
   return mrb_nil_value();
 }
 
+static mrb_value app_mouse_position(mrb_state *mrb, mrb_value) {
+  Vec2<float> mouse_pos = app_->mouse_position;
+  mrb_value result = mrb_hash_new(mrb);
+  HASH_SET(result, x, mrb_float_value(mrb, mouse_pos.x));
+  HASH_SET(result, y, mrb_float_value(mrb, mouse_pos.y));
+  return result;
+}
+
 inline void setup() {
   DEF_CLASS(Font, MRB_ARGS_REQ(2) | MRB_ARGS_OPT(1));
 
@@ -638,6 +686,7 @@ inline void setup() {
   ADD_METHOD(Scene, "delete", scene_delete_element, MRB_ARGS_REQ(1));
   ADD_METHOD(Scene, "remove", scene_delete_element, MRB_ARGS_REQ(1));
   ADD_METHOD(Scene, "on_update", scene_on_update, MRB_ARGS_BLOCK());
+  ADD_METHOD(Scene, "elements_at", scene_elements_at, MRB_ARGS_REQ(1));
 
   DEF_MODULE(App);
   ADD_MODULE_METHOD(App, "run", app_run, MRB_ARGS_REQ(3));
@@ -645,6 +694,7 @@ inline void setup() {
   ADD_MODULE_METHOD(App, "switch_to", app_switch_to, MRB_ARGS_REQ(1));
   ADD_MODULE_METHOD(App, "localize", app_localize, MRB_ARGS_REQ(3));
   ADD_MODULE_METHOD(App, "language=", app_language_set, MRB_ARGS_REQ(1));
+  ADD_MODULE_METHOD(App, "mouse_position", app_mouse_position, MRB_ARGS_NONE());
 }
 } // namespace definitions
 
diff --git a/include/binding/ruby.h b/include/binding/ruby.h
index d8411e6..1aa7bd8 100644
--- a/include/binding/ruby.h
+++ b/include/binding/ruby.h
@@ -9,6 +9,8 @@
 
 #define HASH_GET(h, key) mrb_hash_get(Ruby::mrb, h, SYM(key))
 
+#define HASH_SET(h, key, value) mrb_hash_set(Ruby::mrb, h, SYM(key), value)
+
 #define HASH_FLOAT(h, key, out)     \
   do {                              \
     mrb_value v = HASH_GET(h, key); \
@@ -28,7 +30,7 @@
   } while (0)
 
 struct Wrapper {
-  int id;
+  uint64_t id;
 };
 
 #define ADD_METHOD(NAME, METHOD, FUNC, ARGS) \
diff --git a/include/pch.h b/include/pch.h
index 1a4161d..c780a6b 100644
--- a/include/pch.h
+++ b/include/pch.h
@@ -29,6 +29,7 @@
 
 #include <SDL3/SDL.h>
 #include <SDL3/SDL_events.h>
+#include <SDL3/SDL_mouse.h>
 #include <SDL3_image/SDL_image.h>
 #include <SDL3_ttf/SDL_ttf.h>
 
diff --git a/include/utils.h b/include/utils.h
index 67f6baa..6857558 100644
--- a/include/utils.h
+++ b/include/utils.h
@@ -154,12 +154,13 @@ struct Rect {
 
 template <typename T = void *>
 struct Pool {
-  T *operator[](int index) {
+  T *operator[](uint64_t index) {
     if (!is_valid(index)) {
-      fprintf(stderr, "Invalid pool index: %d\n", index);
+      fprintf(stderr, "Invalid pool index: %llu\n", (unsigned long long)index);
       return nullptr;
     }
-    return slots[index].ptr;
+    uint32_t id = (uint32_t)(index & 0xFFFFFFFFULL);
+    return slots[id].ptr;
   }
 
   const std::vector<T *> &all() {
@@ -171,43 +172,51 @@ struct Pool {
     return all_items;
   }
 
-  int acquire(T *item) {
-    int index;
+  uint64_t acquire(T *item) {
+    uint32_t id;
     if (!free_indices.empty()) {
-      index = free_indices.back();
+      id = free_indices.back();
       free_indices.pop_back();
     } else {
-      index = slots.size();
+      id = slots.size();
       slots.push_back({});
     }
-    slots[index].ptr = item;
-    slots[index].refcount = 1;
-    slots[index].alive = true;
+    slots[id].ptr = item;
+    slots[id].refcount = 1;
+    slots[id].alive = true;
+    slots[id].generation++;
+    uint64_t index = ((uint64_t)slots[id].generation << 32) | id;
     return index;
   }
 
-  void use(int index) {
-    if (is_valid(index))
-      slots[index].refcount++;
+  void use(uint64_t index) {
+    if (is_valid(index)) {
+      uint64_t id = (uint32_t)(index & 0xFFFFFFFFULL);
+      slots[id].refcount++;
+    }
   }
 
-  void release(int index) {
+  void release(uint64_t index) {
     if (!is_valid(index))
       return;
-    auto &slot = slots[index];
+    uint32_t id = (uint32_t)(index & 0xFFFFFFFFULL);
+    auto &slot = slots[id];
     slot.refcount--;
     if (slot.refcount <= 0) {
       delete slot.ptr;
       slot.ptr = nullptr;
       slot.alive = false;
-      free_indices.push_back(index);
+      free_indices.push_back(id);
     }
   }
 
-  bool is_valid(int index) const {
-    return index >= 0
-           && index < (int)slots.size()
-           && slots[index].alive;
+  bool is_valid(uint64_t index) const {
+    uint32_t id = (uint32_t)(index & 0xFFFFFFFFULL);
+    uint32_t gen = (uint32_t)(index >> 32);
+    return id >= 0
+           && id < slots.size()
+           && slots[id].alive
+           && slots[id].generation == gen;
   }
 
 private:
@@ -215,9 +224,10 @@ private:
     T *ptr = nullptr;
     int refcount = 0;
     bool alive = false;
+    uint32_t generation = 0;
   };
   std::vector<Slot> slots;
-  std::vector<int> free_indices;
+  std::vector<uint32_t> free_indices;
 };
 
 #endif
\ No newline at end of file
diff --git a/include/window/window.h b/include/window/window.h
index c85446a..adf7d1c 100644
--- a/include/window/window.h
+++ b/include/window/window.h
@@ -48,6 +48,7 @@ struct Event {
     KEY_DOWN,
     TEXT_INPUT,
     SCROLL,
+    MOUSE_LEAVE,
     MOUSE_BUTTON_UP,
     MOUSE_BUTTON_DOWN,
     MOUSE_MOVE
@@ -80,13 +81,13 @@ struct Event {
 };
 
 struct Animation {
-  std::vector<int> frames;
+  std::vector<uint64_t> frames;
   float frame_rate;
   bool loop;
   int reference_count = 0;
 
   ~Animation() {
-    for (int frame_id : frames)
+    for (uint64_t frame_id : frames)
       image_pool.release(frame_id);
   }
 };
@@ -103,18 +104,18 @@ public:
   ~Window();
 
   // Rendering functions
-  int load_image(const char *path, float alpha = 1.0f, bool pixel_art = false);
-  Vec2<float> get_image_size(int image_id);
+  uint64_t load_image(const char *path, float alpha = 1.0f, bool pixel_art = false);
+  Vec2<float> get_image_size(uint64_t image_id);
 
-  int load_font(const char *path, int font_size, bool bold = false, bool italic = false, bool underline = false, bool pixel_art = false);
+  uint64_t load_font(const char *path, int font_size, bool bold = false, bool italic = false, bool underline = false, bool pixel_art = false);
 
   // text is copied internally, so it can be free'd by the caller after the text is created.
-  int create_text(int font_id, const char *text, uint32_t length, Color color);
-  Vec2<float> get_text_size(int text_id);
+  uint64_t create_text(uint64_t font_id, const char *text, uint32_t length, Color color);
+  Vec2<float> get_text_size(uint64_t text_id);
 
-  bool write(int text_id, Vec2<float> position, float z, float angle = 0.0f, Vec2<float> scale = {1.0f, 1.0f});
+  bool write(uint64_t text_id, Vec2<float> position, float z, float angle = 0.0f, Vec2<float> scale = {1.0f, 1.0f});
 
-  bool draw(int image_id, Vec2<float> position, float z, float angle = 0.0f, Vec2<float> scale = {1.0f, 1.0f});
+  bool draw(uint64_t image_id, Vec2<float> position, float z, float angle = 0.0f, Vec2<float> scale = {1.0f, 1.0f});
 
   bool draw_rect(Rect rect, Color color, float z, float angle = 0.0f);
 
@@ -172,12 +173,12 @@ private:
 
     union {
       struct {
-        int image_id;
+        uint64_t image_id;
         Vec2<float> position;
       } draw_image;
 
       struct {
-        int text_id;
+        uint64_t text_id;
         Vec2<float> position;
       } draw_text;
 
diff --git a/samples/button.rb b/samples/button.rb
index 0f03802..56ccf60 100644
--- a/samples/button.rb
+++ b/samples/button.rb
@@ -16,7 +16,7 @@ text = ElementText.new :btn_text, default_font, position: {x: 50, y: 50}, z: 1,
 
 rect = ElementRect.new({x: 50, y: 50, w: 100, h: 25}, 0xFF0000FF, z: 0)
 
-image_element = ElementImage.new bg_animation, position: {x: 0, y: 0}, z: -1
+image_element = ElementImage.new bg_animation, position: {x: 0, y: 0}, z: -1, click_through: true
 
 rect.on_click do
   rect.color = rect.color == 0xFF0000FF ?
@@ -73,15 +73,17 @@ main_scene.on_update do |delta_time|
   # commented out to avoid spamming the console, but you can uncomment to see the delta time being printed every frame
   # runs at 60fps, so you should see around 16-17ms being printed
 
-  # simple logic to handle hover
-  pos = App.mouse_position
-  next if pos.nil? # mouse position can be nil if the window is not focused, so we skip the hover logic in that case
-  elements = main_scene.elements_at(*pos.values)
-  if elements.include?(rect)
-    rect.color = 0x0000FFFF
-  else # also handles nil case, if the mouse is not over any element, we reset the color
-    rect.color = 0xFF0000FF
+  el = main_scene.elements_at(App.mouse_position)
+  for elem in el
+    if elem == image_element
+      puts "Hovering over image element"
+    elsif elem == rect
+      puts "Hovering over rect element"
+    elsif elem == text
+      puts "Hovering over text element"
+    end
   end
+
 end
 
 main_scene << text
diff --git a/src/window/window.cc b/src/window/window.cc
index 72b77ed..5179b39 100644
--- a/src/window/window.cc
+++ b/src/window/window.cc
@@ -56,7 +56,7 @@ Window::~Window() {
   SDL_Quit();
 }
 
-int Window::load_image(const char *path, float alpha, bool pixel_art) {
+uint64_t Window::load_image(const char *path, float alpha, bool pixel_art) {
   SDL_Texture *texture = IMG_LoadTexture(renderer, path);
 
   if (pixel_art) {
@@ -65,7 +65,7 @@ int Window::load_image(const char *path, float alpha, bool pixel_art) {
 
   if (texture == nullptr) {
     fprintf(stderr, "Failed to load image: %s\n", SDL_GetError());
-    return UINT32_MAX;
+    return UINT64_MAX;
   }
 
   SDL_SetTextureAlphaMod(texture, (uint8_t)(alpha * 255));
@@ -74,26 +74,26 @@ int Window::load_image(const char *path, float alpha, bool pixel_art) {
   SDL_GetTextureSize(texture, &w, &h);
 
   Image *img = new Image{texture, {w, h}};
-  int id = image_pool.acquire(img);
+  uint64_t id = image_pool.acquire(img);
   image_pool.use(id);
 
   return id;
 }
 
-Vec2<float> Window::get_image_size(int image_id) {
+Vec2<float> Window::get_image_size(uint64_t image_id) {
   if (!image_pool.is_valid(image_id)) {
-    fprintf(stderr, "Invalid image ID: %d\n", image_id);
+    fprintf(stderr, "Invalid image ID: %llu\n", (unsigned long long)image_id);
     return {0, 0};
   }
   return image_pool[image_id]->size;
 }
 
-int Window::load_font(const char *path, int font_size, bool bold, bool italic, bool underline, bool pixel_art) {
+uint64_t Window::load_font(const char *path, int font_size, bool bold, bool italic, bool underline, bool pixel_art) {
   TTF_Font *font = TTF_OpenFont(path, font_size);
 
   if (font == nullptr) {
     fprintf(stderr, "Failed to load font: %s\n", SDL_GetError());
-    return UINT32_MAX;
+    return UINT64_MAX;
   }
 
   int style = TTF_STYLE_NORMAL;
@@ -107,16 +107,16 @@ int Window::load_font(const char *path, int font_size, bool bold, bool italic, b
   TTF_SetFontStyle(font, style);
 
   Font *f = new Font{font, pixel_art};
-  int id = font_pool.acquire(f);
+  uint64_t id = font_pool.acquire(f);
   font_pool.use(id);
 
   return id;
 }
 
-int Window::create_text(int font_id, const char *text, uint32_t length, Color color) {
+uint64_t Window::create_text(uint64_t font_id, const char *text, uint32_t length, Color color) {
   if (!font_pool.is_valid(font_id)) {
-    fprintf(stderr, "Invalid font ID: %d\n", font_id);
-    return UINT32_MAX;
+    fprintf(stderr, "Invalid font ID: %llu\n", (unsigned long long)font_id);
+    return UINT64_MAX;
   }
 
   SDL_Color sdl_color = {color.r, color.g, color.b, color.a};
@@ -124,7 +124,7 @@ int Window::create_text(int font_id, const char *text, uint32_t length, Color co
 
   if (surface == nullptr) {
     fprintf(stderr, "Failed to create text surface: %s\n", SDL_GetError());
-    return UINT32_MAX;
+    return UINT64_MAX;
   }
 
   SDL_Texture *texture = SDL_CreateTextureFromSurface(renderer, surface);
@@ -132,7 +132,7 @@ int Window::create_text(int font_id, const char *text, uint32_t length, Color co
 
   if (texture == nullptr) {
     fprintf(stderr, "Failed to create text texture: %s\n", SDL_GetError());
-    return UINT32_MAX;
+    return UINT64_MAX;
   }
 
   if (font_pool[font_id]->pixel_art)
@@ -142,23 +142,24 @@ int Window::create_text(int font_id, const char *text, uint32_t length, Color co
   SDL_GetTextureSize(texture, &w, &h);
 
   Text *t = new Text{texture, {w, h}};
-  int id = text_pool.acquire(t);
+  uint64_t id = text_pool.acquire(t);
   text_pool.use(id);
 
   return id;
 }
 
-Vec2<float> Window::get_text_size(int text_id) {
+Vec2<float> Window::get_text_size(uint64_t text_id) {
   if (!text_pool.is_valid(text_id)) {
-    fprintf(stderr, "Invalid text ID: %d\n", text_id);
+    fprintf(stderr, "(Size) Invalid text ID: %llu\n", (unsigned long long)text_id);
     return {0, 0};
+    throw std::runtime_error("Invalid text ID");
   }
   return text_pool[text_id]->size;
 }
 
-bool Window::write(int text_id, Vec2<float> position, float z, float angle, Vec2<float> scale) {
+bool Window::write(uint64_t text_id, Vec2<float> position, float z, float angle, Vec2<float> scale) {
   if (!text_pool.is_valid(text_id)) {
-    fprintf(stderr, "Invalid text ID: %d\n", text_id);
+    fprintf(stderr, "(Write) Invalid text ID: %llu\n", (unsigned long long)text_id);
     return false;
   }
 
@@ -176,9 +177,9 @@ bool Window::write(int text_id, Vec2<float> position, float z, float angle, Vec2
   return true;
 };
 
-bool Window::draw(int image_id, Vec2<float> position, float z, float angle, Vec2<float> scale) {
+bool Window::draw(uint64_t image_id, Vec2<float> position, float z, float angle, Vec2<float> scale) {
   if (!image_pool.is_valid(image_id)) {
-    fprintf(stderr, "Invalid image ID: %d\n", image_id);
+    fprintf(stderr, "Invalid image ID: %llu\n", (unsigned long long)image_id);
     return false;
   }
 
@@ -382,6 +383,10 @@ bool Window::poll(Event &event) {
       event.text_input.text[event.text_input.length] = '\0';
       break;
 
+    case SDL_EVENT_WINDOW_MOUSE_LEAVE:
+      event.type = Event::MOUSE_LEAVE;
+      break;
+
     case SDL_EVENT_MOUSE_BUTTON_DOWN: {
       event.type = Event::MOUSE_BUTTON_DOWN;
       event.mouse_button.button = sdl_event.button.button;
@@ -389,7 +394,7 @@ bool Window::poll(Event &event) {
       if (mouse_in_window({sdl_event.button.x, sdl_event.button.y}, virtual_position))
         event.mouse_button.position = virtual_position;
       else
-        return false;
+        event.type = Event::MOUSE_LEAVE;
     } break;
 
     case SDL_EVENT_MOUSE_BUTTON_UP: {
@@ -399,17 +404,17 @@ bool Window::poll(Event &event) {
       if (mouse_in_window({sdl_event.button.x, sdl_event.button.y}, virtual_position))
         event.mouse_button.position = virtual_position;
       else
-        return false;
+        event.type = Event::MOUSE_LEAVE;
     } break;
 
     case SDL_EVENT_MOUSE_MOTION: {
       event.type = Event::MOUSE_MOVE;
       event.mouse_move.delta = {sdl_event.motion.xrel, sdl_event.motion.yrel};
       Vec2<float> virtual_position;
-      if (mouse_in_window({sdl_event.button.x, sdl_event.button.y}, virtual_position))
-        event.mouse_button.position = virtual_position;
+      if (mouse_in_window({sdl_event.motion.x, sdl_event.motion.y}, virtual_position))
+        event.mouse_move.position = virtual_position;
       else
-        return false;
+        event.type = Event::MOUSE_LEAVE;
     } break;
 
     case SDL_EVENT_MOUSE_WHEEL: