Highlight them each in turn in your IDE and press F1 twice. That'll display their documentation.
Basically, flip switches the hidden 'background' screen where all the drawing is done to the front so it is visible.
Waitkey...errrr.... waits for a key to be pressed.
Basically, flip switches the hidden 'background' screen where all the drawing is done to the front so it is visible.
Waitkey...errrr.... waits for a key to be pressed.