bevy/examples/input/gamepad_input.rs
s-puig e788e3bc83
Implement gamepads as entities (#12770)
# Objective

- Significantly improve the ergonomics of gamepads and allow new
features

Gamepads are a bit unergonomic to work with, they use resources but
unlike other inputs, they are not limited to a single gamepad, to get
around this it uses an identifier (Gamepad) to interact with anything
causing all sorts of issues.

1. There are too many: Gamepads, GamepadSettings, GamepadInfo,
ButtonInput<T>, 2 Axis<T>.
2. ButtonInput/Axis generic methods become really inconvenient to use
e.g. any_pressed()
3. GamepadButton/Axis structs are unnecessary boilerplate:

```rust
for gamepad in gamepads.iter() {
        if button_inputs.just_pressed(GamepadButton::new(gamepad, GamepadButtonType::South)) {
            info!("{:?} just pressed South", gamepad);
        } else if button_inputs.just_released(GamepadButton::new(gamepad, GamepadButtonType::South))
        {
            info!("{:?} just released South", gamepad);
        }
}
```
4. Projects often need to create resources to store the selected gamepad
and have to manually check if their gamepad is still valid anyways.

- Previously attempted by #3419 and #12674


## Solution

- Implement gamepads as entities.

Using entities solves all the problems above and opens new
possibilities.

1. Reduce boilerplate and allows iteration

```rust
let is_pressed = gamepads_buttons.iter().any(|buttons| buttons.pressed(GamepadButtonType::South))
```
2. ButtonInput/Axis generic methods become ergonomic again 
```rust
gamepad_buttons.any_just_pressed([GamepadButtonType::Start, GamepadButtonType::Select])
```
3. Reduces the number of public components significantly (Gamepad,
GamepadSettings, GamepadButtons, GamepadAxes)
4. Components are highly convenient. Gamepad optional features could now
be expressed naturally (`Option<Rumble> or Option<Gyro>`), allows devs
to attach their own components and filter them, so code like this
becomes possible:
```rust
fn move_player<const T: usize>(
    player: Query<&Transform, With<Player<T>>>,
    gamepads_buttons: Query<&GamepadButtons, With<Player<T>>>,
) {
    if let Ok(gamepad_buttons) = gamepads_buttons.get_single() {
        if gamepad_buttons.pressed(GamepadButtonType::South) {
            // move player
        }
    }
}
```
---

## Follow-up

- [ ] Run conditions?
- [ ] Rumble component

# Changelog

## Added

TODO

## Changed

TODO

## Removed

TODO


## Migration Guide

TODO

---------

Co-authored-by: Carter Anderson <mcanders1@gmail.com>
2024-09-27 20:07:20 +00:00

30 lines
970 B
Rust

//! Shows handling of gamepad input, connections, and disconnections.
use bevy::prelude::*;
fn main() {
App::new()
.add_plugins(DefaultPlugins)
.add_systems(Update, gamepad_system)
.run();
}
fn gamepad_system(gamepads: Query<(Entity, &Gamepad)>) {
for (entity, gamepad) in &gamepads {
if gamepad.just_pressed(GamepadButton::South) {
info!("{:?} just pressed South", entity);
} else if gamepad.just_released(GamepadButton::South) {
info!("{:?} just released South", entity);
}
let right_trigger = gamepad.get(GamepadButton::RightTrigger2).unwrap();
if right_trigger.abs() > 0.01 {
info!("{:?} RightTrigger2 value is {}", entity, right_trigger);
}
let left_stick_x = gamepad.get(GamepadAxis::LeftStickX).unwrap();
if left_stick_x.abs() > 0.01 {
info!("{:?} LeftStickX value is {}", entity, left_stick_x);
}
}
}