testbed: give meaning to the none command

testbed/system/command_system.cpp

@@ -20,11 +20,10 @@ void command_system(entt::registry &registry) {
         case input_listener_component::type::RIGHT:
             vel.dx = 1.0f;
             break;
-        default:
+        case input_listener_component::type::NONE:
+            vel.dx = vel.dy = 0.0f;
             break;
         }
-
-        input.command = input_listener_component::type::NONE;
     }
 }
 

testbed/system/input_system.cpp

@@ -37,6 +37,9 @@ void input_system(entt::registry &registry, const SDL_Event &event, bool &quit)
         case SDLK_RIGHT:
             internal::update_listeners(registry, input_listener_component::type::RIGHT);
             break;
+        case SDLK_SPACE:
+            internal::update_listeners(registry, input_listener_component::type::NONE);
+            break;
         }
         break;
     }