Module tracker 

Frame-to-frame button tracking: edges, auto-repeat, handoff suppression.

Every project grew this trio by hand: gameplay wants just-pressed edges ((new ^ prev) & new), menu cursors want delay-then-rate auto-repeat, and anything that switches contexts (a collection launcher starting a game, a menu opening over gameplay) wants buttons already held at the handoff ignored until re-pressed. One tracker, fed the polled button mask once per frame, answers all three.

let mut pad = PadTracker::new();
loop {
    pad.update(poll_port1().buttons);
    if pad.just_pressed(button::CROSS) { jump(); }
    if pad.repeats(button::DOWN, 15, 4) { cursor_down(); }
}

Structs

PadTracker

Frame-to-frame tracker over an active-high 16-bit button mask (the PadState::buttons representation).