Add global update loop, and cleanup

include/app/app.h

@@ -169,10 +169,9 @@ struct Scene {
     }
   }
 
-  void update_scene(uint64_t delta_time) {
+  void update_scene(mrb_value dt_val) {
     if (mrb_nil_p(update.proc))
       return;
-    mrb_value dt_val = mrb_float_value(Ruby::mrb, delta_time / 1e9);
     update.call(1, &dt_val);
   }
 
@@ -200,6 +199,8 @@ struct Scene {
         } else if (e->click_mode == ClickMode::BLOCK) {
           result.push_back(*it);
           break;
+        } else {
+          continue;
         }
       }
     }
@@ -240,6 +241,7 @@ struct App {
   std::vector<Key> released_keys;
   Vec2<float> scroll = {0, 0};
   std::string text = "";
+  Ruby::Block update;
 
   void exit() {
     running = false;
@@ -335,7 +337,12 @@ struct App {
         }
       }
 
-      scene->update_scene(dt);
+      int ai = mrb_gc_arena_save(Ruby::mrb);
+      mrb_value dt_val = mrb_float_value(Ruby::mrb, dt / 1e9);
+      update.call(1, &dt_val);
+      scene->update_scene(dt_val);
+      mrb_gc_arena_restore(Ruby::mrb, ai);
+
       scene->render(window, window.get_time());
 
       window.render();