bevy/crates/bevy_input/src/touch.rs
Michael Dorst 8aff7262d6 Fix doc_markdown lints in bevy_input (#3475)
#3457 adds the `doc_markdown` clippy lint, which checks doc comments to make sure code identifiers are escaped with backticks. This causes a lot of lint errors, so this is one of a number of PR's that will fix those lint errors one crate at a time.

This PR fixes lints in the `bevy_input` crate.
2021-12-29 17:38:10 +00:00

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use bevy_app::EventReader;
use bevy_ecs::system::ResMut;
use bevy_math::Vec2;
use bevy_utils::HashMap;
/// Represents a touch event
///
/// Every time the user touches the screen, a new `Start` event with an unique
/// identifier for the finger is generated. When the finger is lifted, an `End`
/// event is generated with the same finger id.
///
/// After a `Start` event has been emitted, there may be zero or more `Move`
/// events when the finger is moved or the touch pressure changes.
///
/// The finger id may be reused by the system after an `End` event. The user
/// should assume that a new `Start` event received with the same id has nothing
/// to do with the old finger and is a new finger.
///
/// A `Cancelled` event is emitted when the system has canceled tracking this
/// touch, such as when the window loses focus, or on iOS if the user moves the
/// device against their face.
#[derive(Debug, Clone, Copy, PartialEq)]
pub struct TouchInput {
pub phase: TouchPhase,
pub position: Vec2,
/// Describes how hard the screen was pressed. May be `None` if the platform
/// does not support pressure sensitivity.
///
/// ## Platform-specific
///
/// - Only available on **iOS** 9.0+ and **Windows** 8+.
pub force: Option<ForceTouch>,
/// Unique identifier of a finger.
pub id: u64,
}
/// Describes the force of a touch event
#[derive(Debug, Clone, Copy, PartialEq)]
pub enum ForceTouch {
/// On iOS, the force is calibrated so that the same number corresponds to
/// roughly the same amount of pressure on the screen regardless of the
/// device.
Calibrated {
/// The force of the touch, where a value of 1.0 represents the force of
/// an average touch (predetermined by the system, not user-specific).
///
/// The force reported by Apple Pencil is measured along the axis of the
/// pencil. If you want a force perpendicular to the device, you need to
/// calculate this value using the `altitude_angle` value.
force: f64,
/// The maximum possible force for a touch.
///
/// The value of this field is sufficiently high to provide a wide
/// dynamic range for values of the `force` field.
max_possible_force: f64,
/// The altitude (in radians) of the stylus.
///
/// A value of 0 radians indicates that the stylus is parallel to the
/// surface. The value of this property is Pi/2 when the stylus is
/// perpendicular to the surface.
altitude_angle: Option<f64>,
},
/// If the platform reports the force as normalized, we have no way of
/// knowing how much pressure 1.0 corresponds to we know it's the maximum
/// amount of force, but as to how much force, you might either have to
/// press really really hard, or not hard at all, depending on the device.
Normalized(f64),
}
/// Describes touch-screen input state.
#[derive(Debug, Hash, PartialEq, Eq, Clone, Copy)]
#[cfg_attr(feature = "serialize", derive(serde::Serialize, serde::Deserialize))]
pub enum TouchPhase {
Started,
Moved,
Ended,
Cancelled,
}
#[derive(Debug, Clone, Copy)]
pub struct Touch {
id: u64,
start_position: Vec2,
start_force: Option<ForceTouch>,
previous_position: Vec2,
previous_force: Option<ForceTouch>,
position: Vec2,
force: Option<ForceTouch>,
}
impl Touch {
pub fn delta(&self) -> Vec2 {
self.position - self.previous_position
}
pub fn distance(&self) -> Vec2 {
self.position - self.start_position
}
#[inline]
pub fn id(&self) -> u64 {
self.id
}
#[inline]
pub fn start_position(&self) -> Vec2 {
self.start_position
}
#[inline]
pub fn start_force(&self) -> Option<ForceTouch> {
self.start_force
}
#[inline]
pub fn previous_position(&self) -> Vec2 {
self.previous_position
}
#[inline]
pub fn position(&self) -> Vec2 {
self.position
}
#[inline]
pub fn force(&self) -> Option<ForceTouch> {
self.force
}
}
impl From<&TouchInput> for Touch {
fn from(input: &TouchInput) -> Touch {
Touch {
id: input.id,
start_position: input.position,
start_force: input.force,
previous_position: input.position,
previous_force: input.force,
position: input.position,
force: input.force,
}
}
}
#[derive(Debug, Clone, Default)]
pub struct Touches {
pressed: HashMap<u64, Touch>,
just_pressed: HashMap<u64, Touch>,
just_released: HashMap<u64, Touch>,
just_cancelled: HashMap<u64, Touch>,
}
impl Touches {
pub fn iter(&self) -> impl Iterator<Item = &Touch> + '_ {
self.pressed.values()
}
pub fn get_pressed(&self, id: u64) -> Option<&Touch> {
self.pressed.get(&id)
}
pub fn just_pressed(&self, id: u64) -> bool {
self.just_pressed.contains_key(&id)
}
pub fn iter_just_pressed(&self) -> impl Iterator<Item = &Touch> {
self.just_pressed.values()
}
pub fn get_released(&self, id: u64) -> Option<&Touch> {
self.just_released.get(&id)
}
pub fn just_released(&self, id: u64) -> bool {
self.just_released.contains_key(&id)
}
pub fn iter_just_released(&self) -> impl Iterator<Item = &Touch> {
self.just_released.values()
}
pub fn just_cancelled(&self, id: u64) -> bool {
self.just_cancelled.contains_key(&id)
}
pub fn iter_just_cancelled(&self) -> impl Iterator<Item = &Touch> {
self.just_cancelled.values()
}
fn process_touch_event(&mut self, event: &TouchInput) {
match event.phase {
TouchPhase::Started => {
self.pressed.insert(event.id, event.into());
self.just_pressed.insert(event.id, event.into());
}
TouchPhase::Moved => {
if let Some(mut new_touch) = self.pressed.get(&event.id).cloned() {
new_touch.previous_position = new_touch.position;
new_touch.previous_force = new_touch.force;
new_touch.position = event.position;
new_touch.force = event.force;
self.pressed.insert(event.id, new_touch);
}
}
TouchPhase::Ended => {
self.just_released.insert(event.id, event.into());
self.pressed.remove_entry(&event.id);
}
TouchPhase::Cancelled => {
self.just_cancelled.insert(event.id, event.into());
self.pressed.remove_entry(&event.id);
}
};
}
fn update(&mut self) {
self.just_pressed.clear();
self.just_released.clear();
self.just_cancelled.clear();
}
}
/// Updates the `Touches` resource with the latest `TouchInput` events
pub fn touch_screen_input_system(
mut touch_state: ResMut<Touches>,
mut touch_input_events: EventReader<TouchInput>,
) {
touch_state.update();
for event in touch_input_events.iter() {
touch_state.process_touch_event(event);
}
}
#[cfg(test)]
mod test {
#[test]
fn touch_update() {
use crate::{touch::Touch, Touches};
use bevy_math::Vec2;
let mut touches = Touches::default();
let touch_event = Touch {
id: 4,
start_position: Vec2::new(0.0, 0.0),
start_force: None,
previous_position: Vec2::new(0.0, 0.0),
previous_force: None,
position: Vec2::new(0.0, 0.0),
force: None,
};
// Add a touch to `just_pressed`, 'just_released', and 'just cancelled'
touches.just_pressed.insert(4, touch_event);
touches.just_released.insert(4, touch_event);
touches.just_cancelled.insert(4, touch_event);
touches.update();
// Verify that all the `just_x` maps are cleared
assert!(touches.just_pressed.is_empty());
assert!(touches.just_released.is_empty());
assert!(touches.just_cancelled.is_empty());
}
#[test]
fn touch_process() {
use crate::{touch::TouchPhase, TouchInput, Touches};
use bevy_math::Vec2;
let mut touches = Touches::default();
// Test adding a `TouchPhase::Started`
let touch_event = TouchInput {
phase: TouchPhase::Started,
position: Vec2::new(4.0, 4.0),
force: None,
id: 4,
};
touches.update();
touches.process_touch_event(&touch_event);
assert!(touches.pressed.get(&touch_event.id).is_some());
assert!(touches.just_pressed.get(&touch_event.id).is_some());
// Test adding a `TouchPhase::Moved`
let moved_touch_event = TouchInput {
phase: TouchPhase::Moved,
position: Vec2::new(5.0, 5.0),
force: None,
id: touch_event.id,
};
touches.update();
touches.process_touch_event(&moved_touch_event);
assert_eq!(
touches
.pressed
.get(&moved_touch_event.id)
.expect("Missing from pressed after move.")
.previous_position,
touch_event.position
);
// Test cancelling an event
let cancel_touch_event = TouchInput {
phase: TouchPhase::Cancelled,
position: Vec2::new(1.0, 1.0),
force: None,
id: touch_event.id,
};
touches.update();
touches.process_touch_event(&cancel_touch_event);
assert!(touches.just_cancelled.get(&cancel_touch_event.id).is_some());
assert!(touches.pressed.get(&cancel_touch_event.id).is_none());
// Test ending an event
let end_touch_event = TouchInput {
phase: TouchPhase::Ended,
position: Vec2::new(4.0, 4.0),
force: None,
id: 4,
};
touches.update();
touches.process_touch_event(&touch_event);
touches.process_touch_event(&end_touch_event);
assert!(touches.just_released.get(&touch_event.id).is_some());
assert!(touches.pressed.get(&touch_event.id).is_none());
}
#[test]
fn touch_pressed() {
use crate::{touch::TouchPhase, TouchInput, Touches};
use bevy_math::Vec2;
let mut touches = Touches::default();
let touch_event = TouchInput {
phase: TouchPhase::Started,
position: Vec2::new(4.0, 4.0),
force: None,
id: 4,
};
// Register the touch and test that it was registered correctly
touches.process_touch_event(&touch_event);
assert!(touches.get_pressed(touch_event.id).is_some());
assert!(touches.just_pressed(touch_event.id));
assert_eq!(touches.iter().count(), 1);
}
#[test]
fn touch_released() {
use crate::{touch::TouchPhase, TouchInput, Touches};
use bevy_math::Vec2;
let mut touches = Touches::default();
let touch_event = TouchInput {
phase: TouchPhase::Ended,
position: Vec2::new(4.0, 4.0),
force: None,
id: 4,
};
// Register the touch and test that it was registered correctly
touches.process_touch_event(&touch_event);
assert!(touches.get_released(touch_event.id).is_some());
assert!(touches.just_released(touch_event.id));
assert_eq!(touches.iter_just_released().count(), 1);
}
#[test]
fn touch_cancelled() {
use crate::{touch::TouchPhase, TouchInput, Touches};
use bevy_math::Vec2;
let mut touches = Touches::default();
let touch_event = TouchInput {
phase: TouchPhase::Cancelled,
position: Vec2::new(4.0, 4.0),
force: None,
id: 4,
};
// Register the touch and test that it was registered correctly
touches.process_touch_event(&touch_event);
assert!(touches.just_cancelled(touch_event.id));
assert_eq!(touches.iter_just_cancelled().count(), 1);
}
}