1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
use bevy_ecs::{system::Commands, world::World};
use log::debug;
use crate::state::{FreelyMutableState, NextState};
/// Extension trait for [`Commands`] adding `bevy_state` helpers.
pub trait CommandsStatesExt {
/// Sets the next state the app should move to.
///
/// Internally this schedules a command that updates the [`NextState<S>`](crate::prelude::NextState)
/// resource with `state`.
///
/// Note that commands introduce sync points to the ECS schedule, so modifying `NextState`
/// directly may be more efficient depending on your use-case.
fn set_state<S: FreelyMutableState>(&mut self, state: S);
/// Sets the next state the app should move to, skipping any state transitions if the next state is the same as the current state.
///
/// Internally this schedules a command that updates the [`NextState<S>`](crate::prelude::NextState)
/// resource with `state`.
///
/// Note that commands introduce sync points to the ECS schedule, so modifying `NextState`
/// directly may be more efficient depending on your use-case.
fn set_state_if_neq<S: FreelyMutableState>(&mut self, state: S);
}
impl CommandsStatesExt for Commands<'_, '_> {
fn set_state<S: FreelyMutableState>(&mut self, state: S) {
self.queue(move |w: &mut World| {
let mut next = w.resource_mut::<NextState<S>>();
if let NextState::PendingIfNeq(prev) = &*next {
debug!("overwriting next state {prev:?} with {state:?}");
}
next.set(state);
});
}
fn set_state_if_neq<S: FreelyMutableState>(&mut self, state: S) {
self.queue(move |w: &mut World| {
let mut next = w.resource_mut::<NextState<S>>();
if let NextState::PendingIfNeq(prev) = &*next
&& *prev != state
{
debug!("overwriting next state {prev:?} with {state:?} if not equal");
}
next.set_if_neq(state);
});
}
}