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use super::button_event::ButtonEvent;
use super::button::Button;
use super::button_state::ButtonState;
use crate::ctypes::*;
/// The state of all buttons, along with changes since the last frame.
#[derive(Debug)]
pub struct Buttons {
current: CButtons,
up_events: [Option<ButtonEvent>; 3],
down_events: [Option<ButtonEvent>; 3],
left_events: [Option<ButtonEvent>; 3],
right_events: [Option<ButtonEvent>; 3],
b_events: [Option<ButtonEvent>; 3],
a_events: [Option<ButtonEvent>; 3],
}
impl Buttons {
pub(crate) fn new(button_state_per_frame: &[PDButtonsSet; 2]) -> Self {
Buttons {
current: button_state_per_frame[0].current,
up_events: Self::compute_events(&button_state_per_frame, CButtons::kButtonUp),
down_events: Self::compute_events(&button_state_per_frame, CButtons::kButtonDown),
left_events: Self::compute_events(&button_state_per_frame, CButtons::kButtonLeft),
right_events: Self::compute_events(&button_state_per_frame, CButtons::kButtonRight),
b_events: Self::compute_events(&button_state_per_frame, CButtons::kButtonB),
a_events: Self::compute_events(&button_state_per_frame, CButtons::kButtonA),
}
}
/// Infer a sequence of events for a button between 2 frames by combining the button's last pushed
/// state, current pushed state, and whether a push and/or release happened in between frames.
fn compute_events(frames: &[PDButtonsSet; 2], button: CButtons) -> [Option<ButtonEvent>; 3] {
// Last frame: pushed.
if frames[1].current & button == button {
// Last frame: pushed. || Current frame: [released].
if frames[0].current & button != button {
// Was pushed between frames.
if frames[0].pushed & button == button {
// pushed || released -> pushed -> [released]
[
Some(ButtonEvent::Release),
Some(ButtonEvent::Push),
Some(ButtonEvent::Release),
]
}
// Was not pushed between frames.
else {
// pushed || [released]
[Some(ButtonEvent::Release), None, None]
}
}
// Last frame: pushed. || Current frame: [pushed].
else {
// Was pushed between frames.
if frames[0].pushed & button == button {
// pushed || released -> [pushed]
[Some(ButtonEvent::Release), Some(ButtonEvent::Push), None]
}
// Was not pushed between frames.
else {
// [pushed] ||
[None, None, None]
}
}
}
// Last frame: released.
else {
// Last frame: released. || Current frame: [pushed]
if frames[0].current & button == button {
// Was released between frames.
if frames[0].released & button == button {
// released || pushed -> released -> [pushed]
[
Some(ButtonEvent::Push),
Some(ButtonEvent::Release),
Some(ButtonEvent::Push),
]
}
// Was not released between frames.
else {
// released || pushed
[Some(ButtonEvent::Push), None, None]
}
}
// Last frame: released. || Current frame: [released].
else {
// Was released between frames.
if frames[0].released & button == button {
// released || pushed -> [released]
[Some(ButtonEvent::Push), Some(ButtonEvent::Release), None]
}
// Was not released between frames.
else {
// [released] ||
[None, None, None]
}
}
}
}
/// Helper function to convert the Playdate C Api bitmask to the ButtonState enum for a single
/// button.
#[inline]
fn current_state(&self, button: CButtons) -> ButtonState {
if self.current & button != CButtons(0) {
ButtonState::Pushed
} else {
ButtonState::Released
}
}
/// Returns an iterator over all button events that occured since the last frame.
///
/// This reports any buttons which were pressed or released. The device does not report the order
/// in which buttons were interacted with, so the order of events across buttons is arbitrary.
/// Events for a single button are in an accurate order.
pub fn all_events(&self) -> impl Iterator<Item = (Button, ButtonEvent)> + '_ {
self
.up_events()
.map(|e| (Button::Up, e))
.chain(self.down_events().map(|e| (Button::Down, e)))
.chain(self.left_events().map(|e| (Button::Left, e)))
.chain(self.right_events().map(|e| (Button::Right, e)))
.chain(self.b_events().map(|e| (Button::B, e)))
.chain(self.a_events().map(|e| (Button::A, e)))
}
/// Returns an iterator over all button events, on the `Up` button, that occred since the last
/// frame.
pub fn up_events(&self) -> impl Iterator<Item = ButtonEvent> + '_ {
self.up_events.iter().filter_map(move |o| *o)
}
/// Returns an iterator over all button events, on the `Down` button, that occred since the last
/// frame.
pub fn down_events(&self) -> impl Iterator<Item = ButtonEvent> + '_ {
self.down_events.iter().filter_map(move |o| *o)
}
/// Returns an iterator over all button events, on the `Left` button, that occred since the last
/// frame.
pub fn left_events(&self) -> impl Iterator<Item = ButtonEvent> + '_ {
self.left_events.iter().filter_map(move |o| *o)
}
/// Returns an iterator over all button events, on the `Right` button, that occred since the last
/// frame.
pub fn right_events(&self) -> impl Iterator<Item = ButtonEvent> + '_ {
self.right_events.iter().filter_map(move |o| *o)
}
/// Returns an iterator over all button events, on the `B` button, that occred since the last
/// frame.
pub fn b_events(&self) -> impl Iterator<Item = ButtonEvent> + '_ {
self.b_events.iter().filter_map(move |o| *o)
}
/// Returns an iterator over all button events, on the `A` button, that occred since the last
/// frame.
pub fn a_events(&self) -> impl Iterator<Item = ButtonEvent> + '_ {
self.a_events.iter().filter_map(move |o| *o)
}
/// Returns the current state of the `Up` button.
///
/// Prefer to use the events functions to track button press and release, as this function would
/// miss push+release sequences that are faster than a single frame.
pub fn up_state(&self) -> ButtonState {
self.current_state(CButtons::kButtonUp)
}
/// Returns the current state of the `Down` button.
///
/// Prefer to use the events functions to track button press and release, as this function would
/// miss push+release sequences that are faster than a single frame.
pub fn down_state(&self) -> ButtonState {
self.current_state(CButtons::kButtonDown)
}
/// Returns the current state of the `Left` button.
///
/// Prefer to use the events functions to track button press and release, as this function would
/// miss push+release sequences that are faster than a single frame.
pub fn left_state(&self) -> ButtonState {
self.current_state(CButtons::kButtonLeft)
}
/// Returns the current state of the `Right` button.
///
/// Prefer to use the events functions to track button press and release, as this function would
/// miss push+release sequences that are faster than a single frame.
pub fn right_state(&self) -> ButtonState {
self.current_state(CButtons::kButtonRight)
}
/// Returns the current state of the `B` button.
///
/// Prefer to use the events functions to track button press and release, as this function would
/// miss push+release sequences that are faster than a single frame.
pub fn b_state(&self) -> ButtonState {
self.current_state(CButtons::kButtonB)
}
/// Returns the current state of the `A` button.
///
/// Prefer to use the events functions to track button press and release, as this function would
/// miss push+release sequences that are faster than a single frame.
pub fn a_state(&self) -> ButtonState {
self.current_state(CButtons::kButtonA)
}
}