mirror of
https://github.com/bevyengine/bevy
synced 2024-12-22 11:03:06 +00:00
993 lines
32 KiB
Rust
993 lines
32 KiB
Rust
//! Types that detect when their internal data mutate.
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use crate::{
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component::{Tick, TickCells},
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ptr::PtrMut,
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system::Resource,
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};
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use bevy_ptr::{Ptr, UnsafeCellDeref};
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use std::ops::{Deref, DerefMut};
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/// The (arbitrarily chosen) minimum number of world tick increments between `check_tick` scans.
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///
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/// Change ticks can only be scanned when systems aren't running. Thus, if the threshold is `N`,
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/// the maximum is `2 * N - 1` (i.e. the world ticks `N - 1` times, then `N` times).
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///
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/// If no change is older than `u32::MAX - (2 * N - 1)` following a scan, none of their ages can
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/// overflow and cause false positives.
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// (518,400,000 = 1000 ticks per frame * 144 frames per second * 3600 seconds per hour)
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pub const CHECK_TICK_THRESHOLD: u32 = 518_400_000;
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/// The maximum change tick difference that won't overflow before the next `check_tick` scan.
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///
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/// Changes stop being detected once they become this old.
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pub const MAX_CHANGE_AGE: u32 = u32::MAX - (2 * CHECK_TICK_THRESHOLD - 1);
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/// Types that can read change detection information.
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/// This change detection is controlled by [`DetectChangesMut`] types such as [`ResMut`].
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///
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/// ## Example
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/// Using types that implement [`DetectChanges`], such as [`Res`], provide
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/// a way to query if a value has been mutated in another system.
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///
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/// ```
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/// use bevy_ecs::prelude::*;
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///
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/// #[derive(Resource)]
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/// struct MyResource(u32);
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///
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/// fn my_system(mut resource: Res<MyResource>) {
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/// if resource.is_changed() {
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/// println!("My component was mutated!");
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/// }
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/// }
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/// ```
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pub trait DetectChanges {
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/// Returns `true` if this value was added after the system last ran.
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fn is_added(&self) -> bool;
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/// Returns `true` if this value was added or mutably dereferenced after the system last ran.
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fn is_changed(&self) -> bool;
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/// Returns the change tick recording the time this data was most recently changed.
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///
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/// Note that components and resources are also marked as changed upon insertion.
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///
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/// For comparison, the previous change tick of a system can be read using the
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/// [`SystemChangeTick`](crate::system::SystemChangeTick)
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/// [`SystemParam`](crate::system::SystemParam).
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fn last_changed(&self) -> Tick;
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}
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/// Types that implement reliable change detection.
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///
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/// ## Example
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/// Using types that implement [`DetectChangesMut`], such as [`ResMut`], provide
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/// a way to query if a value has been mutated in another system.
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/// Normally change detection is triggered by either [`DerefMut`] or [`AsMut`], however
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/// it can be manually triggered via [`set_if_neq`](`DetectChangesMut::set_changed`).
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///
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/// To ensure that changes are only triggered when the value actually differs,
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/// check if the value would change before assignment, such as by checking that `new != old`.
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/// You must be *sure* that you are not mutably dereferencing in this process.
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///
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/// [`set_if_neq`](DetectChangesMut::set_if_neq) is a helper
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/// method for this common functionality.
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///
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/// ```
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/// use bevy_ecs::prelude::*;
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///
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/// #[derive(Resource)]
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/// struct MyResource(u32);
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///
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/// fn my_system(mut resource: ResMut<MyResource>) {
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/// if resource.is_changed() {
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/// println!("My resource was mutated!");
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/// }
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///
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/// resource.0 = 42; // triggers change detection via [`DerefMut`]
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/// }
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/// ```
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///
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pub trait DetectChangesMut: DetectChanges {
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/// The type contained within this smart pointer
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///
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/// For example, for `ResMut<T>` this would be `T`.
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type Inner: ?Sized;
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/// Flags this value as having been changed.
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///
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/// Mutably accessing this smart pointer will automatically flag this value as having been changed.
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/// However, mutation through interior mutability requires manual reporting.
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///
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/// **Note**: This operation cannot be undone.
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fn set_changed(&mut self);
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/// Manually sets the change tick recording the time when this data was last mutated.
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///
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/// # Warning
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/// This is a complex and error-prone operation, primarily intended for use with rollback networking strategies.
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/// If you merely want to flag this data as changed, use [`set_changed`](DetectChangesMut::set_changed) instead.
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/// If you want to avoid triggering change detection, use [`bypass_change_detection`](DetectChangesMut::bypass_change_detection) instead.
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fn set_last_changed(&mut self, last_changed: Tick);
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/// Manually bypasses change detection, allowing you to mutate the underlying value without updating the change tick.
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///
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/// # Warning
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/// This is a risky operation, that can have unexpected consequences on any system relying on this code.
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/// However, it can be an essential escape hatch when, for example,
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/// you are trying to synchronize representations using change detection and need to avoid infinite recursion.
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fn bypass_change_detection(&mut self) -> &mut Self::Inner;
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/// Overwrites this smart pointer with the given value, if and only if `*self != value`
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///
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/// This is useful to ensure change detection is only triggered when the underlying value
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/// changes, instead of every time it is mutably accessed.
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///
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/// # Examples
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///
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/// ```
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/// # use bevy_ecs::{prelude::*, schedule::common_conditions::resource_changed};
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/// #[derive(Resource, PartialEq, Eq)]
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/// pub struct Score(u32);
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///
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/// fn reset_score(mut score: ResMut<Score>) {
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/// // Set the score to zero, unless it is already zero.
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/// score.set_if_neq(Score(0));
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/// }
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/// # let mut world = World::new();
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/// # world.insert_resource(Score(1));
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/// # let mut score_changed = IntoSystem::into_system(resource_changed::<Score>());
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/// # score_changed.initialize(&mut world);
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/// # score_changed.run((), &mut world);
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/// #
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/// # let mut schedule = Schedule::new();
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/// # schedule.add_systems(reset_score);
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/// #
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/// # // first time `reset_score` runs, the score is changed.
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/// # schedule.run(&mut world);
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/// # assert!(score_changed.run((), &mut world));
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/// # // second time `reset_score` runs, the score is not changed.
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/// # schedule.run(&mut world);
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/// # assert!(!score_changed.run((), &mut world));
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/// ```
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#[inline]
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fn set_if_neq(&mut self, value: Self::Inner)
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where
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Self::Inner: Sized + PartialEq,
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{
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let old = self.bypass_change_detection();
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if *old != value {
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*old = value;
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self.set_changed();
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}
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}
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}
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macro_rules! change_detection_impl {
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($name:ident < $( $generics:tt ),+ >, $target:ty, $($traits:ident)?) => {
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impl<$($generics),* : ?Sized $(+ $traits)?> DetectChanges for $name<$($generics),*> {
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#[inline]
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fn is_added(&self) -> bool {
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self.ticks
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.added
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.is_newer_than(self.ticks.last_run, self.ticks.this_run)
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}
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#[inline]
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fn is_changed(&self) -> bool {
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self.ticks
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.changed
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.is_newer_than(self.ticks.last_run, self.ticks.this_run)
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}
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#[inline]
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fn last_changed(&self) -> Tick {
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*self.ticks.changed
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}
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}
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impl<$($generics),*: ?Sized $(+ $traits)?> Deref for $name<$($generics),*> {
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type Target = $target;
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#[inline]
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fn deref(&self) -> &Self::Target {
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self.value
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}
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}
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impl<$($generics),* $(: $traits)?> AsRef<$target> for $name<$($generics),*> {
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#[inline]
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fn as_ref(&self) -> &$target {
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self.deref()
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}
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}
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}
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}
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macro_rules! change_detection_mut_impl {
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($name:ident < $( $generics:tt ),+ >, $target:ty, $($traits:ident)?) => {
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impl<$($generics),* : ?Sized $(+ $traits)?> DetectChangesMut for $name<$($generics),*> {
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type Inner = $target;
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#[inline]
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fn set_changed(&mut self) {
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*self.ticks.changed = self.ticks.this_run;
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}
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#[inline]
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fn set_last_changed(&mut self, last_changed: Tick) {
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*self.ticks.changed = last_changed;
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}
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#[inline]
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fn bypass_change_detection(&mut self) -> &mut Self::Inner {
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self.value
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}
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}
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impl<$($generics),* : ?Sized $(+ $traits)?> DerefMut for $name<$($generics),*> {
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#[inline]
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fn deref_mut(&mut self) -> &mut Self::Target {
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self.set_changed();
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self.value
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}
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}
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impl<$($generics),* $(: $traits)?> AsMut<$target> for $name<$($generics),*> {
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#[inline]
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fn as_mut(&mut self) -> &mut $target {
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self.deref_mut()
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}
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}
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};
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}
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macro_rules! impl_methods {
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($name:ident < $( $generics:tt ),+ >, $target:ty, $($traits:ident)?) => {
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impl<$($generics),* : ?Sized $(+ $traits)?> $name<$($generics),*> {
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/// Consume `self` and return a mutable reference to the
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/// contained value while marking `self` as "changed".
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#[inline]
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pub fn into_inner(mut self) -> &'a mut $target {
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self.set_changed();
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self.value
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}
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/// Returns a `Mut<>` with a smaller lifetime.
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/// This is useful if you have `&mut
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#[doc = stringify!($name)]
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/// <T>`, but you need a `Mut<T>`.
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pub fn reborrow(&mut self) -> Mut<'_, $target> {
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Mut {
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value: self.value,
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ticks: TicksMut {
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added: self.ticks.added,
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changed: self.ticks.changed,
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last_run: self.ticks.last_run,
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this_run: self.ticks.this_run,
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}
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}
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}
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/// Maps to an inner value by applying a function to the contained reference, without flagging a change.
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///
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/// You should never modify the argument passed to the closure -- if you want to modify the data
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/// without flagging a change, consider using [`DetectChangesMut::bypass_change_detection`] to make your intent explicit.
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///
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/// ```rust
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/// # use bevy_ecs::prelude::*;
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/// # #[derive(PartialEq)] pub struct Vec2;
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/// # impl Vec2 { pub const ZERO: Self = Self; }
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/// # #[derive(Component)] pub struct Transform { translation: Vec2 }
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/// // When run, zeroes the translation of every entity.
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/// fn reset_positions(mut transforms: Query<&mut Transform>) {
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/// for transform in &mut transforms {
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/// // We pinky promise not to modify `t` within the closure.
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/// // Breaking this promise will result in logic errors, but will never cause undefined behavior.
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/// let mut translation = transform.map_unchanged(|t| &mut t.translation);
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/// // Only reset the translation if it isn't already zero;
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/// translation.set_if_neq(Vec2::ZERO);
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/// }
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/// }
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/// # bevy_ecs::system::assert_is_system(reset_positions);
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/// ```
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pub fn map_unchanged<U: ?Sized>(self, f: impl FnOnce(&mut $target) -> &mut U) -> Mut<'a, U> {
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Mut {
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value: f(self.value),
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ticks: self.ticks,
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}
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}
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}
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};
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}
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macro_rules! impl_debug {
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($name:ident < $( $generics:tt ),+ >, $($traits:ident)?) => {
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impl<$($generics),* : ?Sized $(+ $traits)?> std::fmt::Debug for $name<$($generics),*>
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where T: std::fmt::Debug
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{
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fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
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f.debug_tuple(stringify!($name))
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.field(&self.value)
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.finish()
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}
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}
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};
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}
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#[derive(Clone)]
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pub(crate) struct Ticks<'a> {
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pub(crate) added: &'a Tick,
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pub(crate) changed: &'a Tick,
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pub(crate) last_run: Tick,
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pub(crate) this_run: Tick,
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}
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impl<'a> Ticks<'a> {
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/// # Safety
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/// This should never alias the underlying ticks with a mutable one such as `TicksMut`.
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#[inline]
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pub(crate) unsafe fn from_tick_cells(
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cells: TickCells<'a>,
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last_run: Tick,
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this_run: Tick,
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) -> Self {
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Self {
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added: cells.added.deref(),
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changed: cells.changed.deref(),
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last_run,
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this_run,
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}
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}
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}
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pub(crate) struct TicksMut<'a> {
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pub(crate) added: &'a mut Tick,
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pub(crate) changed: &'a mut Tick,
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pub(crate) last_run: Tick,
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pub(crate) this_run: Tick,
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}
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impl<'a> TicksMut<'a> {
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/// # Safety
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/// This should never alias the underlying ticks. All access must be unique.
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#[inline]
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pub(crate) unsafe fn from_tick_cells(
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cells: TickCells<'a>,
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last_run: Tick,
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this_run: Tick,
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) -> Self {
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Self {
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added: cells.added.deref_mut(),
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changed: cells.changed.deref_mut(),
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last_run,
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this_run,
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}
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}
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}
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impl<'a> From<TicksMut<'a>> for Ticks<'a> {
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fn from(ticks: TicksMut<'a>) -> Self {
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Ticks {
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added: ticks.added,
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changed: ticks.changed,
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last_run: ticks.last_run,
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this_run: ticks.this_run,
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}
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}
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}
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/// Shared borrow of a [`Resource`].
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///
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/// See the [`Resource`] documentation for usage.
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///
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/// If you need a unique mutable borrow, use [`ResMut`] instead.
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///
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/// # Panics
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///
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/// Panics when used as a [`SystemParameter`](crate::system::SystemParam) if the resource does not exist.
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///
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/// Use `Option<Res<T>>` instead if the resource might not always exist.
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pub struct Res<'w, T: ?Sized + Resource> {
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pub(crate) value: &'w T,
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pub(crate) ticks: Ticks<'w>,
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}
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impl<'w, T: Resource> Res<'w, T> {
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// no it shouldn't clippy
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#[allow(clippy::should_implement_trait)]
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pub fn clone(this: &Self) -> Self {
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Self {
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value: this.value,
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ticks: this.ticks.clone(),
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}
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}
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/// Due to lifetime limitations of the `Deref` trait, this method can be used to obtain a
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/// reference of the [`Resource`] with a lifetime bound to `'w` instead of the lifetime of the
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/// struct itself.
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pub fn into_inner(self) -> &'w T {
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self.value
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}
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}
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impl<'w, T: Resource> From<ResMut<'w, T>> for Res<'w, T> {
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fn from(res: ResMut<'w, T>) -> Self {
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Self {
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value: res.value,
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ticks: res.ticks.into(),
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}
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}
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}
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impl<'w, 'a, T: Resource> IntoIterator for &'a Res<'w, T>
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where
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&'a T: IntoIterator,
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{
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type Item = <&'a T as IntoIterator>::Item;
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type IntoIter = <&'a T as IntoIterator>::IntoIter;
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fn into_iter(self) -> Self::IntoIter {
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self.value.into_iter()
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}
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}
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change_detection_impl!(Res<'w, T>, T, Resource);
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impl_debug!(Res<'w, T>, Resource);
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/// Unique mutable borrow of a [`Resource`].
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///
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/// See the [`Resource`] documentation for usage.
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///
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/// If you need a shared borrow, use [`Res`](crate::system::Res) instead.
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///
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/// # Panics
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///
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/// Panics when used as a [`SystemParam`](crate::system::SystemParam) if the resource does not exist.
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///
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/// Use `Option<ResMut<T>>` instead if the resource might not always exist.
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pub struct ResMut<'a, T: ?Sized + Resource> {
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pub(crate) value: &'a mut T,
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pub(crate) ticks: TicksMut<'a>,
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}
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impl<'w, 'a, T: Resource> IntoIterator for &'a ResMut<'w, T>
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where
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&'a T: IntoIterator,
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{
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type Item = <&'a T as IntoIterator>::Item;
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type IntoIter = <&'a T as IntoIterator>::IntoIter;
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fn into_iter(self) -> Self::IntoIter {
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self.value.into_iter()
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}
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}
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impl<'w, 'a, T: Resource> IntoIterator for &'a mut ResMut<'w, T>
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where
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&'a mut T: IntoIterator,
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{
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type Item = <&'a mut T as IntoIterator>::Item;
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type IntoIter = <&'a mut T as IntoIterator>::IntoIter;
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fn into_iter(self) -> Self::IntoIter {
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self.set_changed();
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self.value.into_iter()
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}
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}
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change_detection_impl!(ResMut<'a, T>, T, Resource);
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change_detection_mut_impl!(ResMut<'a, T>, T, Resource);
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impl_methods!(ResMut<'a, T>, T, Resource);
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impl_debug!(ResMut<'a, T>, Resource);
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impl<'a, T: Resource> From<ResMut<'a, T>> for Mut<'a, T> {
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/// Convert this `ResMut` into a `Mut`. This allows keeping the change-detection feature of `Mut`
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/// while losing the specificity of `ResMut` for resources.
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fn from(other: ResMut<'a, T>) -> Mut<'a, T> {
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Mut {
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value: other.value,
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ticks: other.ticks,
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}
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|
}
|
|
}
|
|
|
|
/// Unique borrow of a non-[`Send`] resource.
|
|
///
|
|
/// Only [`Send`] resources may be accessed with the [`ResMut`] [`SystemParam`](crate::system::SystemParam). In case that the
|
|
/// resource does not implement `Send`, this `SystemParam` wrapper can be used. This will instruct
|
|
/// the scheduler to instead run the system on the main thread so that it doesn't send the resource
|
|
/// over to another thread.
|
|
///
|
|
/// # Panics
|
|
///
|
|
/// Panics when used as a `SystemParameter` if the resource does not exist.
|
|
///
|
|
/// Use `Option<NonSendMut<T>>` instead if the resource might not always exist.
|
|
pub struct NonSendMut<'a, T: ?Sized + 'static> {
|
|
pub(crate) value: &'a mut T,
|
|
pub(crate) ticks: TicksMut<'a>,
|
|
}
|
|
|
|
change_detection_impl!(NonSendMut<'a, T>, T,);
|
|
change_detection_mut_impl!(NonSendMut<'a, T>, T,);
|
|
impl_methods!(NonSendMut<'a, T>, T,);
|
|
impl_debug!(NonSendMut<'a, T>,);
|
|
|
|
impl<'a, T: 'static> From<NonSendMut<'a, T>> for Mut<'a, T> {
|
|
/// Convert this `NonSendMut` into a `Mut`. This allows keeping the change-detection feature of `Mut`
|
|
/// while losing the specificity of `NonSendMut`.
|
|
fn from(other: NonSendMut<'a, T>) -> Mut<'a, T> {
|
|
Mut {
|
|
value: other.value,
|
|
ticks: other.ticks,
|
|
}
|
|
}
|
|
}
|
|
|
|
/// Shared borrow of an entity's component with access to change detection.
|
|
/// Similar to [`Mut`] but is immutable and so doesn't require unique access.
|
|
pub struct Ref<'a, T: ?Sized> {
|
|
pub(crate) value: &'a T,
|
|
pub(crate) ticks: Ticks<'a>,
|
|
}
|
|
|
|
impl<'a, T: ?Sized> Ref<'a, T> {
|
|
pub fn into_inner(self) -> &'a T {
|
|
self.value
|
|
}
|
|
}
|
|
|
|
impl<'w, 'a, T> IntoIterator for &'a Ref<'w, T>
|
|
where
|
|
&'a T: IntoIterator,
|
|
{
|
|
type Item = <&'a T as IntoIterator>::Item;
|
|
type IntoIter = <&'a T as IntoIterator>::IntoIter;
|
|
|
|
fn into_iter(self) -> Self::IntoIter {
|
|
self.value.into_iter()
|
|
}
|
|
}
|
|
change_detection_impl!(Ref<'a, T>, T,);
|
|
impl_debug!(Ref<'a, T>,);
|
|
|
|
/// Unique mutable borrow of an entity's component
|
|
pub struct Mut<'a, T: ?Sized> {
|
|
pub(crate) value: &'a mut T,
|
|
pub(crate) ticks: TicksMut<'a>,
|
|
}
|
|
|
|
impl<'a, T: ?Sized> Mut<'a, T> {
|
|
/// Creates a new change-detection enabled smart pointer.
|
|
/// In almost all cases you do not need to call this method manually,
|
|
/// as instances of `Mut` will be created by engine-internal code.
|
|
///
|
|
/// Many use-cases of this method would be better served by [`Mut::map_unchanged`]
|
|
/// or [`Mut::reborrow`].
|
|
///
|
|
/// - `value` - The value wrapped by this smart pointer.
|
|
/// - `added` - A [`Tick`] that stores the tick when the wrapped value was created.
|
|
/// - `last_changed` - A [`Tick`] that stores the last time the wrapped value was changed.
|
|
/// This will be updated to the value of `change_tick` if the returned smart pointer
|
|
/// is modified.
|
|
/// - `last_run` - A [`Tick`], occurring before `this_run`, which is used
|
|
/// as a reference to determine whether the wrapped value is newly added or changed.
|
|
/// - `this_run` - A [`Tick`] corresponding to the current point in time -- "now".
|
|
pub fn new(
|
|
value: &'a mut T,
|
|
added: &'a mut Tick,
|
|
last_changed: &'a mut Tick,
|
|
last_run: Tick,
|
|
this_run: Tick,
|
|
) -> Self {
|
|
Self {
|
|
value,
|
|
ticks: TicksMut {
|
|
added,
|
|
changed: last_changed,
|
|
last_run,
|
|
this_run,
|
|
},
|
|
}
|
|
}
|
|
}
|
|
|
|
impl<'a, T: ?Sized> From<Mut<'a, T>> for Ref<'a, T> {
|
|
fn from(mut_ref: Mut<'a, T>) -> Self {
|
|
Self {
|
|
value: mut_ref.value,
|
|
ticks: mut_ref.ticks.into(),
|
|
}
|
|
}
|
|
}
|
|
|
|
impl<'w, 'a, T> IntoIterator for &'a Mut<'w, T>
|
|
where
|
|
&'a T: IntoIterator,
|
|
{
|
|
type Item = <&'a T as IntoIterator>::Item;
|
|
type IntoIter = <&'a T as IntoIterator>::IntoIter;
|
|
|
|
fn into_iter(self) -> Self::IntoIter {
|
|
self.value.into_iter()
|
|
}
|
|
}
|
|
|
|
impl<'w, 'a, T> IntoIterator for &'a mut Mut<'w, T>
|
|
where
|
|
&'a mut T: IntoIterator,
|
|
{
|
|
type Item = <&'a mut T as IntoIterator>::Item;
|
|
type IntoIter = <&'a mut T as IntoIterator>::IntoIter;
|
|
|
|
fn into_iter(self) -> Self::IntoIter {
|
|
self.set_changed();
|
|
self.value.into_iter()
|
|
}
|
|
}
|
|
|
|
change_detection_impl!(Mut<'a, T>, T,);
|
|
change_detection_mut_impl!(Mut<'a, T>, T,);
|
|
impl_methods!(Mut<'a, T>, T,);
|
|
impl_debug!(Mut<'a, T>,);
|
|
|
|
/// Unique mutable borrow of resources or an entity's component.
|
|
///
|
|
/// Similar to [`Mut`], but not generic over the component type, instead
|
|
/// exposing the raw pointer as a `*mut ()`.
|
|
///
|
|
/// Usually you don't need to use this and can instead use the APIs returning a
|
|
/// [`Mut`], but in situations where the types are not known at compile time
|
|
/// or are defined outside of rust this can be used.
|
|
pub struct MutUntyped<'a> {
|
|
pub(crate) value: PtrMut<'a>,
|
|
pub(crate) ticks: TicksMut<'a>,
|
|
}
|
|
|
|
impl<'a> MutUntyped<'a> {
|
|
/// Returns the pointer to the value, marking it as changed.
|
|
///
|
|
/// In order to avoid marking the value as changed, you need to call [`bypass_change_detection`](DetectChangesMut::bypass_change_detection).
|
|
#[inline]
|
|
pub fn into_inner(mut self) -> PtrMut<'a> {
|
|
self.set_changed();
|
|
self.value
|
|
}
|
|
|
|
/// Returns a [`MutUntyped`] with a smaller lifetime.
|
|
/// This is useful if you have `&mut MutUntyped`, but you need a `MutUntyped`.
|
|
#[inline]
|
|
pub fn reborrow(&mut self) -> MutUntyped {
|
|
MutUntyped {
|
|
value: self.value.reborrow(),
|
|
ticks: TicksMut {
|
|
added: self.ticks.added,
|
|
changed: self.ticks.changed,
|
|
last_run: self.ticks.last_run,
|
|
this_run: self.ticks.this_run,
|
|
},
|
|
}
|
|
}
|
|
|
|
/// Returns a pointer to the value without taking ownership of this smart pointer, marking it as changed.
|
|
///
|
|
/// In order to avoid marking the value as changed, you need to call [`bypass_change_detection`](DetectChangesMut::bypass_change_detection).
|
|
#[inline]
|
|
pub fn as_mut(&mut self) -> PtrMut<'_> {
|
|
self.set_changed();
|
|
self.value.reborrow()
|
|
}
|
|
|
|
/// Returns an immutable pointer to the value without taking ownership.
|
|
#[inline]
|
|
pub fn as_ref(&self) -> Ptr<'_> {
|
|
self.value.as_ref()
|
|
}
|
|
|
|
/// Transforms this [`MutUntyped`] into a [`Mut<T>`] with the same lifetime.
|
|
///
|
|
/// # Safety
|
|
/// - `T` must be the erased pointee type for this [`MutUntyped`].
|
|
pub unsafe fn with_type<T>(self) -> Mut<'a, T> {
|
|
Mut {
|
|
value: self.value.deref_mut(),
|
|
ticks: self.ticks,
|
|
}
|
|
}
|
|
}
|
|
|
|
impl<'a> DetectChanges for MutUntyped<'a> {
|
|
#[inline]
|
|
fn is_added(&self) -> bool {
|
|
self.ticks
|
|
.added
|
|
.is_newer_than(self.ticks.last_run, self.ticks.this_run)
|
|
}
|
|
|
|
#[inline]
|
|
fn is_changed(&self) -> bool {
|
|
self.ticks
|
|
.changed
|
|
.is_newer_than(self.ticks.last_run, self.ticks.this_run)
|
|
}
|
|
|
|
#[inline]
|
|
fn last_changed(&self) -> Tick {
|
|
*self.ticks.changed
|
|
}
|
|
}
|
|
|
|
impl<'a> DetectChangesMut for MutUntyped<'a> {
|
|
type Inner = PtrMut<'a>;
|
|
|
|
#[inline]
|
|
fn set_changed(&mut self) {
|
|
*self.ticks.changed = self.ticks.this_run;
|
|
}
|
|
|
|
#[inline]
|
|
fn set_last_changed(&mut self, last_changed: Tick) {
|
|
*self.ticks.changed = last_changed;
|
|
}
|
|
|
|
#[inline]
|
|
fn bypass_change_detection(&mut self) -> &mut Self::Inner {
|
|
&mut self.value
|
|
}
|
|
}
|
|
|
|
impl std::fmt::Debug for MutUntyped<'_> {
|
|
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
|
|
f.debug_tuple("MutUntyped")
|
|
.field(&self.value.as_ptr())
|
|
.finish()
|
|
}
|
|
}
|
|
|
|
#[cfg(test)]
|
|
mod tests {
|
|
use bevy_ecs_macros::Resource;
|
|
|
|
use crate::{
|
|
self as bevy_ecs,
|
|
change_detection::{
|
|
Mut, NonSendMut, Ref, ResMut, TicksMut, CHECK_TICK_THRESHOLD, MAX_CHANGE_AGE,
|
|
},
|
|
component::{Component, ComponentTicks, Tick},
|
|
system::{IntoSystem, Query, System},
|
|
world::World,
|
|
};
|
|
|
|
use super::DetectChanges;
|
|
use super::DetectChangesMut;
|
|
|
|
#[derive(Component, PartialEq)]
|
|
struct C;
|
|
|
|
#[derive(Resource)]
|
|
struct R;
|
|
|
|
#[derive(Resource, PartialEq)]
|
|
struct R2(u8);
|
|
|
|
#[test]
|
|
fn change_expiration() {
|
|
fn change_detected(query: Query<Ref<C>>) -> bool {
|
|
query.single().is_changed()
|
|
}
|
|
|
|
fn change_expired(query: Query<Ref<C>>) -> bool {
|
|
query.single().is_changed()
|
|
}
|
|
|
|
let mut world = World::new();
|
|
|
|
// component added: 1, changed: 1
|
|
world.spawn(C);
|
|
|
|
let mut change_detected_system = IntoSystem::into_system(change_detected);
|
|
let mut change_expired_system = IntoSystem::into_system(change_expired);
|
|
change_detected_system.initialize(&mut world);
|
|
change_expired_system.initialize(&mut world);
|
|
|
|
// world: 1, system last ran: 0, component changed: 1
|
|
// The spawn will be detected since it happened after the system "last ran".
|
|
assert!(change_detected_system.run((), &mut world));
|
|
|
|
// world: 1 + MAX_CHANGE_AGE
|
|
let change_tick = world.change_tick.get_mut();
|
|
*change_tick = change_tick.wrapping_add(MAX_CHANGE_AGE);
|
|
|
|
// Both the system and component appeared `MAX_CHANGE_AGE` ticks ago.
|
|
// Since we clamp things to `MAX_CHANGE_AGE` for determinism,
|
|
// `ComponentTicks::is_changed` will now see `MAX_CHANGE_AGE > MAX_CHANGE_AGE`
|
|
// and return `false`.
|
|
assert!(!change_expired_system.run((), &mut world));
|
|
}
|
|
|
|
#[test]
|
|
fn change_tick_wraparound() {
|
|
fn change_detected(query: Query<Ref<C>>) -> bool {
|
|
query.single().is_changed()
|
|
}
|
|
|
|
let mut world = World::new();
|
|
world.last_change_tick = Tick::new(u32::MAX);
|
|
*world.change_tick.get_mut() = 0;
|
|
|
|
// component added: 0, changed: 0
|
|
world.spawn(C);
|
|
|
|
// system last ran: u32::MAX
|
|
let mut change_detected_system = IntoSystem::into_system(change_detected);
|
|
change_detected_system.initialize(&mut world);
|
|
|
|
// Since the world is always ahead, as long as changes can't get older than `u32::MAX` (which we ensure),
|
|
// the wrapping difference will always be positive, so wraparound doesn't matter.
|
|
assert!(change_detected_system.run((), &mut world));
|
|
}
|
|
|
|
#[test]
|
|
fn change_tick_scan() {
|
|
let mut world = World::new();
|
|
|
|
// component added: 1, changed: 1
|
|
world.spawn(C);
|
|
|
|
// a bunch of stuff happens, the component is now older than `MAX_CHANGE_AGE`
|
|
*world.change_tick.get_mut() += MAX_CHANGE_AGE + CHECK_TICK_THRESHOLD;
|
|
let change_tick = world.change_tick();
|
|
|
|
let mut query = world.query::<Ref<C>>();
|
|
for tracker in query.iter(&world) {
|
|
let ticks_since_insert = change_tick.relative_to(*tracker.ticks.added).get();
|
|
let ticks_since_change = change_tick.relative_to(*tracker.ticks.changed).get();
|
|
assert!(ticks_since_insert > MAX_CHANGE_AGE);
|
|
assert!(ticks_since_change > MAX_CHANGE_AGE);
|
|
}
|
|
|
|
// scan change ticks and clamp those at risk of overflow
|
|
world.check_change_ticks();
|
|
|
|
for tracker in query.iter(&world) {
|
|
let ticks_since_insert = change_tick.relative_to(*tracker.ticks.added).get();
|
|
let ticks_since_change = change_tick.relative_to(*tracker.ticks.changed).get();
|
|
assert!(ticks_since_insert == MAX_CHANGE_AGE);
|
|
assert!(ticks_since_change == MAX_CHANGE_AGE);
|
|
}
|
|
}
|
|
|
|
#[test]
|
|
fn mut_from_res_mut() {
|
|
let mut component_ticks = ComponentTicks {
|
|
added: Tick::new(1),
|
|
changed: Tick::new(2),
|
|
};
|
|
let ticks = TicksMut {
|
|
added: &mut component_ticks.added,
|
|
changed: &mut component_ticks.changed,
|
|
last_run: Tick::new(3),
|
|
this_run: Tick::new(4),
|
|
};
|
|
let mut res = R {};
|
|
let res_mut = ResMut {
|
|
value: &mut res,
|
|
ticks,
|
|
};
|
|
|
|
let into_mut: Mut<R> = res_mut.into();
|
|
assert_eq!(1, into_mut.ticks.added.get());
|
|
assert_eq!(2, into_mut.ticks.changed.get());
|
|
assert_eq!(3, into_mut.ticks.last_run.get());
|
|
assert_eq!(4, into_mut.ticks.this_run.get());
|
|
}
|
|
|
|
#[test]
|
|
fn mut_new() {
|
|
let mut component_ticks = ComponentTicks {
|
|
added: Tick::new(1),
|
|
changed: Tick::new(3),
|
|
};
|
|
let mut res = R {};
|
|
|
|
let val = Mut::new(
|
|
&mut res,
|
|
&mut component_ticks.added,
|
|
&mut component_ticks.changed,
|
|
Tick::new(2), // last_run
|
|
Tick::new(4), // this_run
|
|
);
|
|
|
|
assert!(!val.is_added());
|
|
assert!(val.is_changed());
|
|
}
|
|
|
|
#[test]
|
|
fn mut_from_non_send_mut() {
|
|
let mut component_ticks = ComponentTicks {
|
|
added: Tick::new(1),
|
|
changed: Tick::new(2),
|
|
};
|
|
let ticks = TicksMut {
|
|
added: &mut component_ticks.added,
|
|
changed: &mut component_ticks.changed,
|
|
last_run: Tick::new(3),
|
|
this_run: Tick::new(4),
|
|
};
|
|
let mut res = R {};
|
|
let non_send_mut = NonSendMut {
|
|
value: &mut res,
|
|
ticks,
|
|
};
|
|
|
|
let into_mut: Mut<R> = non_send_mut.into();
|
|
assert_eq!(1, into_mut.ticks.added.get());
|
|
assert_eq!(2, into_mut.ticks.changed.get());
|
|
assert_eq!(3, into_mut.ticks.last_run.get());
|
|
assert_eq!(4, into_mut.ticks.this_run.get());
|
|
}
|
|
|
|
#[test]
|
|
fn map_mut() {
|
|
use super::*;
|
|
struct Outer(i64);
|
|
|
|
let last_run = Tick::new(2);
|
|
let this_run = Tick::new(3);
|
|
let mut component_ticks = ComponentTicks {
|
|
added: Tick::new(1),
|
|
changed: Tick::new(2),
|
|
};
|
|
let ticks = TicksMut {
|
|
added: &mut component_ticks.added,
|
|
changed: &mut component_ticks.changed,
|
|
last_run,
|
|
this_run,
|
|
};
|
|
|
|
let mut outer = Outer(0);
|
|
let ptr = Mut {
|
|
value: &mut outer,
|
|
ticks,
|
|
};
|
|
assert!(!ptr.is_changed());
|
|
|
|
// Perform a mapping operation.
|
|
let mut inner = ptr.map_unchanged(|x| &mut x.0);
|
|
assert!(!inner.is_changed());
|
|
|
|
// Mutate the inner value.
|
|
*inner = 64;
|
|
assert!(inner.is_changed());
|
|
// Modifying one field of a component should flag a change for the entire component.
|
|
assert!(component_ticks.is_changed(last_run, this_run));
|
|
}
|
|
|
|
#[test]
|
|
fn set_if_neq() {
|
|
let mut world = World::new();
|
|
|
|
world.insert_resource(R2(0));
|
|
// Resources are Changed when first added
|
|
world.increment_change_tick();
|
|
// This is required to update world::last_change_tick
|
|
world.clear_trackers();
|
|
|
|
let mut r = world.resource_mut::<R2>();
|
|
assert!(!r.is_changed(), "Resource must begin unchanged.");
|
|
|
|
r.set_if_neq(R2(0));
|
|
assert!(
|
|
!r.is_changed(),
|
|
"Resource must not be changed after setting to the same value."
|
|
);
|
|
|
|
r.set_if_neq(R2(3));
|
|
assert!(
|
|
r.is_changed(),
|
|
"Resource must be changed after setting to a different value."
|
|
);
|
|
}
|
|
}
|