The description of the opcode FX0A is:
Wait for a keypress and store the result in register VX
My question is if a key is already pressed while the opcode is called, is it considered a keypress? Or will it not be considered a keypress until the key is released and then pressed again?
In other words, do I need to wait until a value of a key is pressed, or until a value is set from not_pressed to pressed?
(Source)
If we take this literally, "wait for a key press" would imply no previous input, but to simply wait right here and now for a key.
Though perhaps you should just make it configurable in your application.