Reduce update interval when inactive

lib/window.rb

@@ -15,6 +15,9 @@ class W3DHub
         I18n.locale = :en
       end
 
+      @last_interaction = Gosu.milliseconds
+      @last_mouse_position = CyberarmEngine::Vector.new(mouse_x, mouse_y)
+
       # push_state(W3DHub::States::DemoInputDelay)
       push_state(W3DHub::States::Boot)
     end
@@ -23,6 +26,13 @@ class W3DHub
       super
 
       Store.application_manager.start_next_available_task if Store.application_manager.idle?
+      manage_update_interval
+    end
+
+    def button_down(id)
+      super
+
+      @last_interaction = Gosu.milliseconds
     end
 
     def close
@@ -31,6 +41,19 @@ class W3DHub
       super if Store.application_manager.idle?
     end
 
+    def manage_update_interval
+      @last_interaction = Gosu.milliseconds if @last_mouse_position.x != mouse_x || @last_mouse_position.y != mouse_y
+
+      self.update_interval = if Gosu.milliseconds - @last_interaction >= 1_000
+                               1000.0 / 10
+                             else
+                               1000.0 / 60
+                             end
+
+      @last_mouse_position.x = mouse_x
+      @last_mouse_position.y = mouse_y
+    end
+
     def main_thread_queue
       if current_state.is_a?(W3DHub::States::Interface)
         current_state.main_thread_queue