GameScreen

The main screen of the game where all of the actual flight- and waypoint-related logic starts.

Initialisation

Accepts the GameDifficulty variable, which is passed on to AircraftController (AicraftController).

Also initiates all of the UI elements:

// create a table layout, main ui
Table ui = new Table();

// create a separate layout for sidebar with all the buttons and
// required info
Table sidebar = new Table();

// create and add the Airspace group, contains aircraft and waypoints
Airspace airspace = new Airspace();

ui basically holds both the sidebar and airspace, first of which is another table which is used as a wrapper for all of the elements in the sidebar (simplifies management of the layout).