Methods
draw()
Draw this Scene to the camera,
must be overriden by subclass
init()
To initialize the level, called from loop.start(),
should be overriden by subclass
load()
Load the necessary resources,
should be overriden by subclass
next()
Stop the GameLoop and unload this Scene,
Subclasses must call super.next()
(async) start()
Asynchronous method to start this scene in accordance with the GameLoop
stop()
Stop the GameLoop, unload this Scene, and call engine.cleanUp()
unload()
Unload all the loaded resources,
should be overriden by subclass
update()
Update this Scene,
must be overriden by subclass