testbed: refine comment system

testbed/component/input_listener_component.h

@@ -8,7 +8,8 @@ struct input_listener_component {
         UP,
         DOWN,
         LEFT,
-        RIGHT
+        RIGHT,
+        STOP
     };
 
     type command{type::NONE};

testbed/system/command_system.cpp

@@ -20,10 +20,14 @@ void command_system(entt::registry &registry) {
         case input_listener_component::type::RIGHT:
             vel.dx = 1.0f;
             break;
-        case input_listener_component::type::NONE:
+        case input_listener_component::type::STOP:
             vel.dx = vel.dy = 0.0f;
             break;
+        default:
+            break;
         }
+
+        input.command = input_listener_component::type::NONE;
     }
 }
 

testbed/system/input_system.cpp

@@ -38,7 +38,7 @@ void input_system(entt::registry &registry, const SDL_Event &event, bool &quit)
             internal::update_listeners(registry, input_listener_component::type::RIGHT);
             break;
         case SDLK_SPACE:
-            internal::update_listeners(registry, input_listener_component::type::NONE);
+            internal::update_listeners(registry, input_listener_component::type::STOP);
             break;
         }
         break;