use crate::{ archetype::{Archetype, ArchetypeComponentId}, change_detection::Ticks, component::{Component, ComponentId, ComponentStorage, ComponentTicks, StorageType}, entity::Entity, query::{Access, FilteredAccess}, storage::{ComponentSparseSet, Table, Tables}, world::{Mut, World}, }; use bevy_ecs_macros::all_tuples; pub use bevy_ecs_macros::WorldQuery; use std::{ cell::UnsafeCell, marker::PhantomData, ptr::{self, NonNull}, }; /// Types that can be queried from a [`World`]. /// /// Notable types that implement this trait are `&T` and `&mut T` where `T` implements [`Component`], /// allowing you to query for components immutably and mutably accordingly. /// /// See [`Query`](crate::system::Query) for a primer on queries. /// /// # Basic [`WorldQuery`]'s /// /// Here is a small list of the most important world queries to know about where `C` stands for a /// [`Component`] and `WQ` stands for a [`WorldQuery`]: /// - `&C`: Queries immutably for the component `C` /// - `&mut C`: Queries mutably for the component `C` /// - `Option`: Queries the inner [`WorldQuery`] `WQ` but instead of discarding the entity if the world /// query fails it returns [`None`]. See [`Query`](crate::system::Query). /// - `(WQ1, WQ2, ...)`: Queries all contained world queries allowing to query for more than one thing. /// This is the `And` operator for filters. See [`Or`]. /// - `ChangeTrackers`: See the docs of [`ChangeTrackers`]. /// - [`Entity`]: Using the entity type as a world query will grant access to the entity that is /// being queried for. See [`Entity`]. /// /// Bevy also offers a few filters like [`Added`](crate::query::Added), [`Changed`](crate::query::Changed), /// [`With`](crate::query::With), [`Without`](crate::query::Without) and [`Or`]. /// For more information on these consult the item's corresponding documentation. /// /// [`Or`]: crate::query::Or /// /// # Derive /// /// This trait can be derived with the [`derive@super::WorldQuery`] macro. /// /// You may want to implement a custom query with the derive macro for the following reasons: /// - Named structs can be clearer and easier to use than complex query tuples. Access via struct /// fields is more convenient than destructuring tuples or accessing them via `q.0, q.1, ...` /// pattern and saves a lot of maintenance burden when adding or removing components. /// - Nested queries enable the composition pattern and makes query types easier to re-use. /// - You can bypass the limit of 15 components that exists for query tuples. /// /// Implementing the trait manually can allow for a fundamentally new type of behaviour. /// /// The derive macro implements [`WorldQuery`] for your type and declares an additional struct /// which will be used as an item for query iterators. The implementation also generates two other /// structs that implement [`Fetch`] and [`FetchState`] and are used as [`WorldQuery::Fetch`] and /// [`WorldQuery::State`] associated types respectively. /// /// The derive macro requires every struct field to implement the `WorldQuery` trait. /// /// **Note:** currently, the macro only supports named structs. /// /// ``` /// # use bevy_ecs::prelude::*; /// use bevy_ecs::query::WorldQuery; /// /// #[derive(Component)] /// struct Foo; /// #[derive(Component)] /// struct Bar; /// /// #[derive(WorldQuery)] /// struct MyQuery<'w> { /// entity: Entity, /// foo: &'w Foo, /// bar: Option<&'w Bar>, /// } /// /// fn my_system(query: Query) { /// for q in query.iter() { /// // Note the type of the returned item. /// let q: MyQueryItem<'_> = q; /// q.foo; /// } /// } /// /// # bevy_ecs::system::assert_is_system(my_system); /// ``` /// /// ## Mutable queries /// /// All queries that are derived with the `WorldQuery` macro provide only an immutable access by default. /// If you need a mutable access to components, you can mark a struct with the `mutable` attribute. /// /// ``` /// # use bevy_ecs::prelude::*; /// use bevy_ecs::query::WorldQuery; /// /// #[derive(Component)] /// struct Health(f32); /// #[derive(Component)] /// struct Buff(f32); /// /// #[derive(WorldQuery)] /// #[world_query(mutable)] /// struct HealthQuery<'w> { /// health: &'w mut Health, /// buff: Option<&'w mut Buff>, /// } /// /// // This implementation is only available when iterating with `iter_mut`. /// impl<'w> HealthQueryItem<'w> { /// fn damage(&mut self, value: f32) { /// self.health.0 -= value; /// } /// /// fn total(&self) -> f32 { /// self.health.0 + self.buff.as_deref().map_or(0.0, |Buff(buff)| *buff) /// } /// } /// /// // If you want to use it with `iter`, you'll need to write an additional implementation. /// impl<'w> HealthQueryReadOnlyItem<'w> { /// fn total(&self) -> f32 { /// self.health.0 + self.buff.map_or(0.0, |Buff(buff)| *buff) /// } /// } /// /// fn my_system(mut health_query: Query) { /// // Iterator's item is `HealthQueryReadOnlyItem`. /// for health in health_query.iter() { /// println!("Total: {}", health.total()); /// } /// // Iterator's item is `HealthQueryItem`. /// for mut health in health_query.iter_mut() { /// health.damage(1.0); /// println!("Total (mut): {}", health.total()); /// } /// } /// /// # bevy_ecs::system::assert_is_system(my_system); /// ``` /// /// **Note:** if you omit the `mutable` attribute for a query that doesn't implement /// `ReadOnlyFetch`, compilation will fail. We insert static checks as in the example above for /// every query component and a nested query. /// (The checks neither affect the runtime, nor pollute your local namespace.) /// /// ```compile_fail /// # use bevy_ecs::prelude::*; /// use bevy_ecs::query::WorldQuery; /// /// #[derive(Component)] /// struct Foo; /// #[derive(Component)] /// struct Bar; /// /// #[derive(WorldQuery)] /// struct FooQuery<'w> { /// foo: &'w Foo, /// bar_query: BarQuery<'w>, /// } /// /// #[derive(WorldQuery)] /// #[world_query(mutable)] /// struct BarQuery<'w> { /// bar: &'w mut Bar, /// } /// ``` /// /// ## Derives for items /// /// If you want query items to have derivable traits, you can pass them with using /// the `world_query(derive)` attribute. When the `WorldQuery` macro generates the structs /// for query items, it doesn't automatically inherit derives of a query itself. Since derive macros /// can't access information about other derives, they need to be passed manually with the /// `world_query(derive)` attribute. /// /// ``` /// # use bevy_ecs::prelude::*; /// use bevy_ecs::query::WorldQuery; /// /// #[derive(Component, Debug)] /// struct Foo; /// /// #[derive(WorldQuery)] /// #[world_query(mutable, derive(Debug))] /// struct FooQuery<'w> { /// foo: &'w Foo, /// } /// /// fn assert_debug() {} /// /// assert_debug::(); /// assert_debug::(); /// ``` /// /// ## Nested queries /// /// Using nested queries enable the composition pattern, which makes it possible to re-use other /// query types. All types that implement [`WorldQuery`] (including the ones that use this derive /// macro) are supported. /// /// ``` /// # use bevy_ecs::prelude::*; /// use bevy_ecs::query::WorldQuery; /// /// #[derive(Component)] /// struct Foo; /// #[derive(Component)] /// struct Bar; /// #[derive(Component)] /// struct OptionalFoo; /// #[derive(Component)] /// struct OptionalBar; /// /// #[derive(WorldQuery)] /// struct MyQuery<'w> { /// foo: FooQuery<'w>, /// bar: (&'w Bar, Option<&'w OptionalBar>) /// } /// /// #[derive(WorldQuery)] /// struct FooQuery<'w> { /// foo: &'w Foo, /// optional_foo: Option<&'w OptionalFoo>, /// } /// /// // You can also compose derived queries with regular ones in tuples. /// fn my_system(query: Query<(&Foo, MyQuery, FooQuery)>) { /// for (foo, my_query, foo_query) in query.iter() { /// foo; my_query; foo_query; /// } /// } /// /// # bevy_ecs::system::assert_is_system(my_system); /// ``` /// /// ## Ignored fields /// /// The macro also supports `ignore` attribute for struct members. Fields marked with this attribute /// must implement the `Default` trait. /// /// This example demonstrates a query that would iterate over every entity. /// /// ``` /// # use bevy_ecs::prelude::*; /// use bevy_ecs::query::WorldQuery; /// /// #[derive(WorldQuery, Debug)] /// struct EmptyQuery<'w> { /// #[world_query(ignore)] /// _w: std::marker::PhantomData<&'w ()>, /// } /// /// fn my_system(query: Query) { /// for _ in query.iter() {} /// } /// /// # bevy_ecs::system::assert_is_system(my_system); /// ``` /// /// ## Filters /// /// Using [`derive@super::WorldQuery`] macro in conjunctions with the `#[world_query(filter)]` /// attribute allows creating custom query filters. /// /// To do so, all fields in the struct must be filters themselves (their [`WorldQuery::Fetch`] /// associated types should implement [`super::FilterFetch`]). /// /// ``` /// # use bevy_ecs::prelude::*; /// use bevy_ecs::{query::WorldQuery, component::Component}; /// /// #[derive(Component)] /// struct Foo; /// #[derive(Component)] /// struct Bar; /// #[derive(Component)] /// struct Baz; /// #[derive(Component)] /// struct Qux; /// /// #[derive(WorldQuery)] /// #[world_query(filter)] /// struct MyFilter { /// _foo: With, /// _bar: With, /// _or: Or<(With, Changed, Added)>, /// _generic_tuple: (With, Without

), /// #[world_query(ignore)] /// _tp: std::marker::PhantomData<(T, P)>, /// } /// /// fn my_system(query: Query>) { /// for _ in query.iter() {} /// } /// /// # bevy_ecs::system::assert_is_system(my_system); /// ``` pub trait WorldQuery { type Fetch: for<'world, 'state> Fetch<'world, 'state, State = Self::State>; type State: FetchState; type ReadOnlyFetch: for<'world, 'state> Fetch<'world, 'state, State = Self::State> + ReadOnlyFetch; } pub type QueryItem<'w, 's, Q> = <::Fetch as Fetch<'w, 's>>::Item; /// Types that implement this trait are responsible for fetching query items from tables or /// archetypes. /// /// Every type that implements [`WorldQuery`] have their associated [`WorldQuery::Fetch`] and /// [`WorldQuery::State`] types that are essential for fetching component data. pub trait Fetch<'world, 'state>: Sized { type Item; type State: FetchState; /// Creates a new instance of this fetch. /// /// # Safety /// /// `state` must have been initialized (via [`FetchState::init`]) using the same `world` passed /// in to this function. unsafe fn init( world: &World, state: &Self::State, last_change_tick: u32, change_tick: u32, ) -> Self; /// Returns true if (and only if) every table of every archetype matched by this Fetch contains /// all of the matched components. This is used to select a more efficient "table iterator" /// for "dense" queries. If this returns true, [`Fetch::set_table`] and [`Fetch::table_fetch`] /// will be called for iterators. If this returns false, [`Fetch::set_archetype`] and /// [`Fetch::archetype_fetch`] will be called for iterators. const IS_DENSE: bool; /// Returns true if (and only if) this Fetch relies strictly on archetypes to limit which /// components are acessed by the Query. /// /// This enables optimizations for [`crate::query::QueryIter`] that rely on knowing exactly how /// many elements are being iterated (such as `Iterator::collect()`). const IS_ARCHETYPAL: bool; /// Adjusts internal state to account for the next [`Archetype`]. This will always be called on /// archetypes that match this [`Fetch`]. /// /// # Safety /// /// `archetype` and `tables` must be from the [`World`] [`Fetch::init`] was called on. `state` /// must be the [`Self::State`] this was initialized with. unsafe fn set_archetype(&mut self, state: &Self::State, archetype: &Archetype, tables: &Tables); /// Adjusts internal state to account for the next [`Table`]. This will always be called on tables /// that match this [`Fetch`]. /// /// # Safety /// /// `table` must be from the [`World`] [`Fetch::init`] was called on. `state` must be the /// [`Self::State`] this was initialized with. unsafe fn set_table(&mut self, state: &Self::State, table: &Table); /// Fetch [`Self::Item`] for the given `archetype_index` in the current [`Archetype`]. This must /// always be called after [`Fetch::set_archetype`] with an `archetype_index` in the range of /// the current [`Archetype`] /// /// # Safety /// Must always be called _after_ [`Fetch::set_archetype`]. `archetype_index` must be in the range /// of the current archetype unsafe fn archetype_fetch(&mut self, archetype_index: usize) -> Self::Item; /// Fetch [`Self::Item`] for the given `table_row` in the current [`Table`]. This must always be /// called after [`Fetch::set_table`] with a `table_row` in the range of the current [`Table`] /// /// # Safety /// /// Must always be called _after_ [`Fetch::set_table`]. `table_row` must be in the range of the /// current table unsafe fn table_fetch(&mut self, table_row: usize) -> Self::Item; } /// State used to construct a Fetch. This will be cached inside [`QueryState`](crate::query::QueryState), /// so it is best to move as much data / computation here as possible to reduce the cost of /// constructing Fetch. /// /// # Safety /// /// Implementor must ensure that [`FetchState::update_component_access`] and /// [`FetchState::update_archetype_component_access`] exactly reflects the results of /// [`FetchState::matches_archetype`], [`FetchState::matches_table`], [`Fetch::archetype_fetch`], and /// [`Fetch::table_fetch`]. pub unsafe trait FetchState: Send + Sync + Sized { fn init(world: &mut World) -> Self; fn update_component_access(&self, access: &mut FilteredAccess); fn update_archetype_component_access( &self, archetype: &Archetype, access: &mut Access, ); fn matches_archetype(&self, archetype: &Archetype) -> bool; fn matches_table(&self, table: &Table) -> bool; } /// A fetch that is read only. /// /// # Safety /// /// This must only be implemented for read-only fetches. pub unsafe trait ReadOnlyFetch {} impl WorldQuery for Entity { type Fetch = EntityFetch; type State = EntityState; type ReadOnlyFetch = EntityFetch; } /// The [`Fetch`] of [`Entity`]. #[doc(hidden)] #[derive(Clone)] pub struct EntityFetch { entities: *const Entity, } /// SAFETY: access is read only unsafe impl ReadOnlyFetch for EntityFetch {} /// The [`FetchState`] of [`Entity`]. #[doc(hidden)] pub struct EntityState; // SAFETY: no component or archetype access unsafe impl FetchState for EntityState { fn init(_world: &mut World) -> Self { Self } fn update_component_access(&self, _access: &mut FilteredAccess) {} fn update_archetype_component_access( &self, _archetype: &Archetype, _access: &mut Access, ) { } #[inline] fn matches_archetype(&self, _archetype: &Archetype) -> bool { true } #[inline] fn matches_table(&self, _table: &Table) -> bool { true } } impl<'w, 's> Fetch<'w, 's> for EntityFetch { type Item = Entity; type State = EntityState; const IS_DENSE: bool = true; const IS_ARCHETYPAL: bool = true; unsafe fn init( _world: &World, _state: &Self::State, _last_change_tick: u32, _change_tick: u32, ) -> Self { Self { entities: std::ptr::null::(), } } #[inline] unsafe fn set_archetype( &mut self, _state: &Self::State, archetype: &Archetype, _tables: &Tables, ) { self.entities = archetype.entities().as_ptr(); } #[inline] unsafe fn set_table(&mut self, _state: &Self::State, table: &Table) { self.entities = table.entities().as_ptr(); } #[inline] unsafe fn table_fetch(&mut self, table_row: usize) -> Self::Item { *self.entities.add(table_row) } #[inline] unsafe fn archetype_fetch(&mut self, archetype_index: usize) -> Self::Item { *self.entities.add(archetype_index) } } impl WorldQuery for &T { type Fetch = ReadFetch; type State = ReadState; type ReadOnlyFetch = ReadFetch; } /// The [`FetchState`] of `&T`. #[doc(hidden)] pub struct ReadState { component_id: ComponentId, marker: PhantomData, } // SAFETY: component access and archetype component access are properly updated to reflect that T is // read unsafe impl FetchState for ReadState { fn init(world: &mut World) -> Self { let component_id = world.init_component::(); ReadState { component_id, marker: PhantomData, } } fn update_component_access(&self, access: &mut FilteredAccess) { assert!( !access.access().has_write(self.component_id), "&{} conflicts with a previous access in this query. Shared access cannot coincide with exclusive access.", std::any::type_name::(), ); access.add_read(self.component_id); } fn update_archetype_component_access( &self, archetype: &Archetype, access: &mut Access, ) { if let Some(archetype_component_id) = archetype.get_archetype_component_id(self.component_id) { access.add_read(archetype_component_id); } } fn matches_archetype(&self, archetype: &Archetype) -> bool { archetype.contains(self.component_id) } fn matches_table(&self, table: &Table) -> bool { table.has_column(self.component_id) } } /// The [`Fetch`] of `&T`. #[doc(hidden)] pub struct ReadFetch { table_components: NonNull, entity_table_rows: *const usize, entities: *const Entity, sparse_set: *const ComponentSparseSet, } impl Clone for ReadFetch { fn clone(&self) -> Self { Self { table_components: self.table_components, entity_table_rows: self.entity_table_rows, entities: self.entities, sparse_set: self.sparse_set, } } } /// SAFETY: access is read only unsafe impl ReadOnlyFetch for ReadFetch {} impl<'w, 's, T: Component> Fetch<'w, 's> for ReadFetch { type Item = &'w T; type State = ReadState; const IS_DENSE: bool = { match T::Storage::STORAGE_TYPE { StorageType::Table => true, StorageType::SparseSet => false, } }; const IS_ARCHETYPAL: bool = true; unsafe fn init( world: &World, state: &Self::State, _last_change_tick: u32, _change_tick: u32, ) -> Self { let mut value = Self { table_components: NonNull::dangling(), entities: ptr::null::(), entity_table_rows: ptr::null::(), sparse_set: ptr::null::(), }; if T::Storage::STORAGE_TYPE == StorageType::SparseSet { value.sparse_set = world .storages() .sparse_sets .get(state.component_id) .unwrap(); } value } #[inline] unsafe fn set_archetype( &mut self, state: &Self::State, archetype: &Archetype, tables: &Tables, ) { match T::Storage::STORAGE_TYPE { StorageType::Table => { self.entity_table_rows = archetype.entity_table_rows().as_ptr(); let column = tables[archetype.table_id()] .get_column(state.component_id) .unwrap(); self.table_components = column.get_data_ptr().cast::(); } StorageType::SparseSet => self.entities = archetype.entities().as_ptr(), } } #[inline] unsafe fn set_table(&mut self, state: &Self::State, table: &Table) { self.table_components = table .get_column(state.component_id) .unwrap() .get_data_ptr() .cast::(); } #[inline] unsafe fn archetype_fetch(&mut self, archetype_index: usize) -> Self::Item { match T::Storage::STORAGE_TYPE { StorageType::Table => { let table_row = *self.entity_table_rows.add(archetype_index); &*self.table_components.as_ptr().add(table_row) } StorageType::SparseSet => { let entity = *self.entities.add(archetype_index); &*(*self.sparse_set).get(entity).unwrap().cast::() } } } #[inline] unsafe fn table_fetch(&mut self, table_row: usize) -> Self::Item { &*self.table_components.as_ptr().add(table_row) } } impl WorldQuery for &mut T { type Fetch = WriteFetch; type State = WriteState; type ReadOnlyFetch = ReadOnlyWriteFetch; } /// The [`Fetch`] of `&mut T`. #[doc(hidden)] pub struct WriteFetch { table_components: NonNull, table_ticks: *const UnsafeCell, entities: *const Entity, entity_table_rows: *const usize, sparse_set: *const ComponentSparseSet, last_change_tick: u32, change_tick: u32, } impl Clone for WriteFetch { fn clone(&self) -> Self { Self { table_components: self.table_components, table_ticks: self.table_ticks, entities: self.entities, entity_table_rows: self.entity_table_rows, sparse_set: self.sparse_set, last_change_tick: self.last_change_tick, change_tick: self.change_tick, } } } /// The [`ReadOnlyFetch`] of `&mut T`. #[doc(hidden)] pub struct ReadOnlyWriteFetch { table_components: NonNull, entities: *const Entity, entity_table_rows: *const usize, sparse_set: *const ComponentSparseSet, } /// SAFETY: access is read only unsafe impl ReadOnlyFetch for ReadOnlyWriteFetch {} impl Clone for ReadOnlyWriteFetch { fn clone(&self) -> Self { Self { table_components: self.table_components, entities: self.entities, entity_table_rows: self.entity_table_rows, sparse_set: self.sparse_set, } } } /// The [`FetchState`] of `&mut T`. #[doc(hidden)] pub struct WriteState { component_id: ComponentId, marker: PhantomData, } // SAFETY: component access and archetype component access are properly updated to reflect that T is // written unsafe impl FetchState for WriteState { fn init(world: &mut World) -> Self { let component_id = world.init_component::(); WriteState { component_id, marker: PhantomData, } } fn update_component_access(&self, access: &mut FilteredAccess) { assert!( !access.access().has_read(self.component_id), "&mut {} conflicts with a previous access in this query. Mutable component access must be unique.", std::any::type_name::(), ); access.add_write(self.component_id); } fn update_archetype_component_access( &self, archetype: &Archetype, access: &mut Access, ) { if let Some(archetype_component_id) = archetype.get_archetype_component_id(self.component_id) { access.add_write(archetype_component_id); } } fn matches_archetype(&self, archetype: &Archetype) -> bool { archetype.contains(self.component_id) } fn matches_table(&self, table: &Table) -> bool { table.has_column(self.component_id) } } impl<'w, 's, T: Component> Fetch<'w, 's> for WriteFetch { type Item = Mut<'w, T>; type State = WriteState; const IS_DENSE: bool = { match T::Storage::STORAGE_TYPE { StorageType::Table => true, StorageType::SparseSet => false, } }; const IS_ARCHETYPAL: bool = true; unsafe fn init( world: &World, state: &Self::State, last_change_tick: u32, change_tick: u32, ) -> Self { let mut value = Self { table_components: NonNull::dangling(), entities: ptr::null::(), entity_table_rows: ptr::null::(), sparse_set: ptr::null::(), table_ticks: ptr::null::>(), last_change_tick, change_tick, }; if T::Storage::STORAGE_TYPE == StorageType::SparseSet { value.sparse_set = world .storages() .sparse_sets .get(state.component_id) .unwrap(); } value } #[inline] unsafe fn set_archetype( &mut self, state: &Self::State, archetype: &Archetype, tables: &Tables, ) { match T::Storage::STORAGE_TYPE { StorageType::Table => { self.entity_table_rows = archetype.entity_table_rows().as_ptr(); let column = tables[archetype.table_id()] .get_column(state.component_id) .unwrap(); self.table_components = column.get_data_ptr().cast::(); self.table_ticks = column.get_ticks_ptr(); } StorageType::SparseSet => self.entities = archetype.entities().as_ptr(), } } #[inline] unsafe fn set_table(&mut self, state: &Self::State, table: &Table) { let column = table.get_column(state.component_id).unwrap(); self.table_components = column.get_data_ptr().cast::(); self.table_ticks = column.get_ticks_ptr(); } #[inline] unsafe fn archetype_fetch(&mut self, archetype_index: usize) -> Self::Item { match T::Storage::STORAGE_TYPE { StorageType::Table => { let table_row = *self.entity_table_rows.add(archetype_index); Mut { value: &mut *self.table_components.as_ptr().add(table_row), ticks: Ticks { component_ticks: &mut *(*self.table_ticks.add(table_row)).get(), change_tick: self.change_tick, last_change_tick: self.last_change_tick, }, } } StorageType::SparseSet => { let entity = *self.entities.add(archetype_index); let (component, component_ticks) = (*self.sparse_set).get_with_ticks(entity).unwrap(); Mut { value: &mut *component.cast::(), ticks: Ticks { component_ticks: &mut *component_ticks, change_tick: self.change_tick, last_change_tick: self.last_change_tick, }, } } } } #[inline] unsafe fn table_fetch(&mut self, table_row: usize) -> Self::Item { Mut { value: &mut *self.table_components.as_ptr().add(table_row), ticks: Ticks { component_ticks: &mut *(*self.table_ticks.add(table_row)).get(), change_tick: self.change_tick, last_change_tick: self.last_change_tick, }, } } } impl<'w, 's, T: Component> Fetch<'w, 's> for ReadOnlyWriteFetch { type Item = &'w T; type State = WriteState; const IS_DENSE: bool = { match T::Storage::STORAGE_TYPE { StorageType::Table => true, StorageType::SparseSet => false, } }; const IS_ARCHETYPAL: bool = true; unsafe fn init( world: &World, state: &Self::State, _last_change_tick: u32, _change_tick: u32, ) -> Self { let mut value = Self { table_components: NonNull::dangling(), entities: ptr::null::(), entity_table_rows: ptr::null::(), sparse_set: ptr::null::(), }; if T::Storage::STORAGE_TYPE == StorageType::SparseSet { value.sparse_set = world .storages() .sparse_sets .get(state.component_id) .unwrap(); } value } #[inline] unsafe fn set_archetype( &mut self, state: &Self::State, archetype: &Archetype, tables: &Tables, ) { match T::Storage::STORAGE_TYPE { StorageType::Table => { self.entity_table_rows = archetype.entity_table_rows().as_ptr(); let column = tables[archetype.table_id()] .get_column(state.component_id) .unwrap(); self.table_components = column.get_data_ptr().cast::(); } StorageType::SparseSet => self.entities = archetype.entities().as_ptr(), } } #[inline] unsafe fn set_table(&mut self, state: &Self::State, table: &Table) { let column = table.get_column(state.component_id).unwrap(); self.table_components = column.get_data_ptr().cast::(); } #[inline] unsafe fn archetype_fetch(&mut self, archetype_index: usize) -> Self::Item { match T::Storage::STORAGE_TYPE { StorageType::Table => { let table_row = *self.entity_table_rows.add(archetype_index); &*self.table_components.as_ptr().add(table_row) } StorageType::SparseSet => { let entity = *self.entities.add(archetype_index); &*(*self.sparse_set).get(entity).unwrap().cast::() } } } #[inline] unsafe fn table_fetch(&mut self, table_row: usize) -> Self::Item { &*self.table_components.as_ptr().add(table_row) } } impl WorldQuery for Option { type Fetch = OptionFetch; type State = OptionState; type ReadOnlyFetch = OptionFetch; } /// The [`Fetch`] of `Option`. #[doc(hidden)] #[derive(Clone)] pub struct OptionFetch { fetch: T, matches: bool, } /// SAFETY: [`OptionFetch`] is read only because `T` is read only unsafe impl ReadOnlyFetch for OptionFetch {} /// The [`FetchState`] of `Option`. #[doc(hidden)] pub struct OptionState { state: T, } // SAFETY: component access and archetype component access are properly updated according to the // internal Fetch unsafe impl FetchState for OptionState { fn init(world: &mut World) -> Self { Self { state: T::init(world), } } fn update_component_access(&self, access: &mut FilteredAccess) { self.state.update_component_access(access); } fn update_archetype_component_access( &self, archetype: &Archetype, access: &mut Access, ) { if self.state.matches_archetype(archetype) { self.state .update_archetype_component_access(archetype, access); } } fn matches_archetype(&self, _archetype: &Archetype) -> bool { true } fn matches_table(&self, _table: &Table) -> bool { true } } impl<'w, 's, T: Fetch<'w, 's>> Fetch<'w, 's> for OptionFetch { type Item = Option; type State = OptionState; const IS_DENSE: bool = T::IS_DENSE; const IS_ARCHETYPAL: bool = T::IS_ARCHETYPAL; unsafe fn init( world: &World, state: &Self::State, last_change_tick: u32, change_tick: u32, ) -> Self { Self { fetch: T::init(world, &state.state, last_change_tick, change_tick), matches: false, } } #[inline] unsafe fn set_archetype( &mut self, state: &Self::State, archetype: &Archetype, tables: &Tables, ) { self.matches = state.state.matches_archetype(archetype); if self.matches { self.fetch.set_archetype(&state.state, archetype, tables); } } #[inline] unsafe fn set_table(&mut self, state: &Self::State, table: &Table) { self.matches = state.state.matches_table(table); if self.matches { self.fetch.set_table(&state.state, table); } } #[inline] unsafe fn archetype_fetch(&mut self, archetype_index: usize) -> Self::Item { if self.matches { Some(self.fetch.archetype_fetch(archetype_index)) } else { None } } #[inline] unsafe fn table_fetch(&mut self, table_row: usize) -> Self::Item { if self.matches { Some(self.fetch.table_fetch(table_row)) } else { None } } } /// [`WorldQuery`] that tracks changes and additions for component `T`. /// /// Wraps a [`Component`] to track whether the component changed for the corresponding entities in /// a query since the last time the system that includes these queries ran. /// /// If you only care about entities that changed or that got added use the /// [`Changed`](crate::query::Changed) and [`Added`](crate::query::Added) filters instead. /// /// # Examples /// /// ``` /// # use bevy_ecs::component::Component; /// # use bevy_ecs::query::ChangeTrackers; /// # use bevy_ecs::system::IntoSystem; /// # use bevy_ecs::system::Query; /// # /// # #[derive(Component, Debug)] /// # struct Name {}; /// # #[derive(Component)] /// # struct Transform {}; /// # /// fn print_moving_objects_system(query: Query<(&Name, ChangeTrackers)>) { /// for (name, tracker) in query.iter() { /// if tracker.is_changed() { /// println!("Entity moved: {:?}", name); /// } else { /// println!("Entity stood still: {:?}", name); /// } /// } /// } /// # bevy_ecs::system::assert_is_system(print_moving_objects_system); /// ``` #[derive(Clone)] pub struct ChangeTrackers { pub(crate) component_ticks: ComponentTicks, pub(crate) last_change_tick: u32, pub(crate) change_tick: u32, marker: PhantomData, } impl std::fmt::Debug for ChangeTrackers { fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result { f.debug_struct("ChangeTrackers") .field("component_ticks", &self.component_ticks) .field("last_change_tick", &self.last_change_tick) .field("change_tick", &self.change_tick) .finish() } } impl ChangeTrackers { /// Returns true if this component has been added since the last execution of this system. pub fn is_added(&self) -> bool { self.component_ticks .is_added(self.last_change_tick, self.change_tick) } /// Returns true if this component has been changed since the last execution of this system. pub fn is_changed(&self) -> bool { self.component_ticks .is_changed(self.last_change_tick, self.change_tick) } } impl WorldQuery for ChangeTrackers { type Fetch = ChangeTrackersFetch; type State = ChangeTrackersState; type ReadOnlyFetch = ChangeTrackersFetch; } /// The [`FetchState`] of [`ChangeTrackers`]. #[doc(hidden)] pub struct ChangeTrackersState { component_id: ComponentId, marker: PhantomData, } // SAFETY: component access and archetype component access are properly updated to reflect that T is // read unsafe impl FetchState for ChangeTrackersState { fn init(world: &mut World) -> Self { let component_id = world.init_component::(); Self { component_id, marker: PhantomData, } } fn update_component_access(&self, access: &mut FilteredAccess) { assert!( !access.access().has_write(self.component_id), "ChangeTrackers<{}> conflicts with a previous access in this query. Shared access cannot coincide with exclusive access.", std::any::type_name::() ); access.add_read(self.component_id); } fn update_archetype_component_access( &self, archetype: &Archetype, access: &mut Access, ) { if let Some(archetype_component_id) = archetype.get_archetype_component_id(self.component_id) { access.add_read(archetype_component_id); } } fn matches_archetype(&self, archetype: &Archetype) -> bool { archetype.contains(self.component_id) } fn matches_table(&self, table: &Table) -> bool { table.has_column(self.component_id) } } /// The [`Fetch`] of [`ChangeTrackers`]. #[doc(hidden)] pub struct ChangeTrackersFetch { table_ticks: *const ComponentTicks, entity_table_rows: *const usize, entities: *const Entity, sparse_set: *const ComponentSparseSet, marker: PhantomData, last_change_tick: u32, change_tick: u32, } impl Clone for ChangeTrackersFetch { fn clone(&self) -> Self { Self { table_ticks: self.table_ticks, entity_table_rows: self.entity_table_rows, entities: self.entities, sparse_set: self.sparse_set, marker: self.marker, last_change_tick: self.last_change_tick, change_tick: self.change_tick, } } } /// SAFETY: access is read only unsafe impl ReadOnlyFetch for ChangeTrackersFetch {} impl<'w, 's, T: Component> Fetch<'w, 's> for ChangeTrackersFetch { type Item = ChangeTrackers; type State = ChangeTrackersState; const IS_DENSE: bool = { match T::Storage::STORAGE_TYPE { StorageType::Table => true, StorageType::SparseSet => false, } }; const IS_ARCHETYPAL: bool = true; unsafe fn init( world: &World, state: &Self::State, last_change_tick: u32, change_tick: u32, ) -> Self { let mut value = Self { table_ticks: ptr::null::(), entities: ptr::null::(), entity_table_rows: ptr::null::(), sparse_set: ptr::null::(), marker: PhantomData, last_change_tick, change_tick, }; if T::Storage::STORAGE_TYPE == StorageType::SparseSet { value.sparse_set = world .storages() .sparse_sets .get(state.component_id) .unwrap(); } value } #[inline] unsafe fn set_archetype( &mut self, state: &Self::State, archetype: &Archetype, tables: &Tables, ) { match T::Storage::STORAGE_TYPE { StorageType::Table => { self.entity_table_rows = archetype.entity_table_rows().as_ptr(); let column = tables[archetype.table_id()] .get_column(state.component_id) .unwrap(); self.table_ticks = column.get_ticks_const_ptr(); } StorageType::SparseSet => self.entities = archetype.entities().as_ptr(), } } #[inline] unsafe fn set_table(&mut self, state: &Self::State, table: &Table) { self.table_ticks = table .get_column(state.component_id) .unwrap() .get_ticks_const_ptr(); } #[inline] unsafe fn archetype_fetch(&mut self, archetype_index: usize) -> Self::Item { match T::Storage::STORAGE_TYPE { StorageType::Table => { let table_row = *self.entity_table_rows.add(archetype_index); ChangeTrackers { component_ticks: (*self.table_ticks.add(table_row)).clone(), marker: PhantomData, last_change_tick: self.last_change_tick, change_tick: self.change_tick, } } StorageType::SparseSet => { let entity = *self.entities.add(archetype_index); ChangeTrackers { component_ticks: (*self.sparse_set).get_ticks(entity).cloned().unwrap(), marker: PhantomData, last_change_tick: self.last_change_tick, change_tick: self.change_tick, } } } } #[inline] unsafe fn table_fetch(&mut self, table_row: usize) -> Self::Item { ChangeTrackers { component_ticks: (*self.table_ticks.add(table_row)).clone(), marker: PhantomData, last_change_tick: self.last_change_tick, change_tick: self.change_tick, } } } macro_rules! impl_tuple_fetch { ($(($name: ident, $state: ident)),*) => { #[allow(non_snake_case)] impl<'w, 's, $($name: Fetch<'w, 's>),*> Fetch<'w, 's> for ($($name,)*) { type Item = ($($name::Item,)*); type State = ($($name::State,)*); #[allow(clippy::unused_unit)] unsafe fn init(_world: &World, state: &Self::State, _last_change_tick: u32, _change_tick: u32) -> Self { let ($($name,)*) = state; ($($name::init(_world, $name, _last_change_tick, _change_tick),)*) } const IS_DENSE: bool = true $(&& $name::IS_DENSE)*; const IS_ARCHETYPAL: bool = true $(&& $name::IS_ARCHETYPAL)*; #[inline] unsafe fn set_archetype(&mut self, _state: &Self::State, _archetype: &Archetype, _tables: &Tables) { let ($($name,)*) = self; let ($($state,)*) = _state; $($name.set_archetype($state, _archetype, _tables);)* } #[inline] unsafe fn set_table(&mut self, _state: &Self::State, _table: &Table) { let ($($name,)*) = self; let ($($state,)*) = _state; $($name.set_table($state, _table);)* } #[inline] #[allow(clippy::unused_unit)] unsafe fn table_fetch(&mut self, _table_row: usize) -> Self::Item { let ($($name,)*) = self; ($($name.table_fetch(_table_row),)*) } #[inline] #[allow(clippy::unused_unit)] unsafe fn archetype_fetch(&mut self, _archetype_index: usize) -> Self::Item { let ($($name,)*) = self; ($($name.archetype_fetch(_archetype_index),)*) } } // SAFETY: update_component_access and update_archetype_component_access are called for each item in the tuple #[allow(non_snake_case)] #[allow(clippy::unused_unit)] unsafe impl<$($name: FetchState),*> FetchState for ($($name,)*) { fn init(_world: &mut World) -> Self { ($($name::init(_world),)*) } fn update_component_access(&self, _access: &mut FilteredAccess) { let ($($name,)*) = self; $($name.update_component_access(_access);)* } fn update_archetype_component_access(&self, _archetype: &Archetype, _access: &mut Access) { let ($($name,)*) = self; $($name.update_archetype_component_access(_archetype, _access);)* } fn matches_archetype(&self, _archetype: &Archetype) -> bool { let ($($name,)*) = self; true $(&& $name.matches_archetype(_archetype))* } fn matches_table(&self, _table: &Table) -> bool { let ($($name,)*) = self; true $(&& $name.matches_table(_table))* } } impl<$($name: WorldQuery),*> WorldQuery for ($($name,)*) { type Fetch = ($($name::Fetch,)*); type State = ($($name::State,)*); type ReadOnlyFetch = ($($name::ReadOnlyFetch,)*); } /// SAFETY: each item in the tuple is read only unsafe impl<$($name: ReadOnlyFetch),*> ReadOnlyFetch for ($($name,)*) {} }; } /// The `AnyOf` query parameter fetches entities with any of the component types included in T. /// /// `Query>` is equivalent to `Query<(Option<&A>, Option<&B>, Option<&mut C>), (Or(With, With, With)>`. /// Each of the components in `T` is returned as an `Option`, as with `Option` queries. /// Entities are guaranteed to have at least one of the components in `T`. pub struct AnyOf(T); macro_rules! impl_anytuple_fetch { ($(($name: ident, $state: ident)),*) => { #[allow(non_snake_case)] impl<'w, 's, $($name: Fetch<'w, 's>),*> Fetch<'w, 's> for AnyOf<($(($name, bool),)*)> { type Item = ($(Option<$name::Item>,)*); type State = AnyOf<($($name::State,)*)>; #[allow(clippy::unused_unit)] unsafe fn init(_world: &World, state: &Self::State, _last_change_tick: u32, _change_tick: u32) -> Self { let ($($name,)*) = &state.0; AnyOf(($(($name::init(_world, $name, _last_change_tick, _change_tick), false),)*)) } const IS_DENSE: bool = true $(&& $name::IS_DENSE)*; const IS_ARCHETYPAL: bool = true $(&& $name::IS_ARCHETYPAL)*; #[inline] unsafe fn set_archetype(&mut self, _state: &Self::State, _archetype: &Archetype, _tables: &Tables) { let ($($name,)*) = &mut self.0; let ($($state,)*) = &_state.0; $( $name.1 = $state.matches_archetype(_archetype); if $name.1 { $name.0.set_archetype($state, _archetype, _tables); } )* } #[inline] unsafe fn set_table(&mut self, _state: &Self::State, _table: &Table) { let ($($name,)*) = &mut self.0; let ($($state,)*) = &_state.0; $( $name.1 = $state.matches_table(_table); if $name.1 { $name.0.set_table($state, _table); } )* } #[inline] #[allow(clippy::unused_unit)] unsafe fn table_fetch(&mut self, _table_row: usize) -> Self::Item { let ($($name,)*) = &mut self.0; ($( $name.1.then(|| $name.0.table_fetch(_table_row)), )*) } #[inline] #[allow(clippy::unused_unit)] unsafe fn archetype_fetch(&mut self, _archetype_index: usize) -> Self::Item { let ($($name,)*) = &mut self.0; ($( $name.1.then(|| $name.0.archetype_fetch(_archetype_index)), )*) } } // SAFETY: update_component_access and update_archetype_component_access are called for each item in the tuple #[allow(non_snake_case)] #[allow(clippy::unused_unit)] unsafe impl<$($name: FetchState),*> FetchState for AnyOf<($($name,)*)> { fn init(_world: &mut World) -> Self { AnyOf(($($name::init(_world),)*)) } fn update_component_access(&self, _access: &mut FilteredAccess) { let ($($name,)*) = &self.0; $($name.update_component_access(_access);)* } fn update_archetype_component_access(&self, _archetype: &Archetype, _access: &mut Access) { let ($($name,)*) = &self.0; $( if $name.matches_archetype(_archetype) { $name.update_archetype_component_access(_archetype, _access); } )* } fn matches_archetype(&self, _archetype: &Archetype) -> bool { let ($($name,)*) = &self.0; false $(|| $name.matches_archetype(_archetype))* } fn matches_table(&self, _table: &Table) -> bool { let ($($name,)*) = &self.0; false $(|| $name.matches_table(_table))* } } impl<$($name: WorldQuery),*> WorldQuery for AnyOf<($($name,)*)> { type Fetch = AnyOf<($(($name::Fetch, bool),)*)>; type ReadOnlyFetch = AnyOf<($(($name::ReadOnlyFetch, bool),)*)>; type State = AnyOf<($($name::State,)*)>; } /// SAFETY: each item in the tuple is read only unsafe impl<$($name: ReadOnlyFetch),*> ReadOnlyFetch for AnyOf<($(($name, bool),)*)> {} }; } all_tuples!(impl_tuple_fetch, 0, 15, F, S); all_tuples!(impl_anytuple_fetch, 0, 15, F, S); /// [`Fetch`] that does not actually fetch anything /// /// Mostly useful when something is generic over the Fetch and you don't want to fetch as you will discard the result pub struct NopFetch { state: PhantomData, } impl<'w, 's, State: FetchState> Fetch<'w, 's> for NopFetch { type Item = (); type State = State; const IS_DENSE: bool = true; const IS_ARCHETYPAL: bool = true; #[inline(always)] unsafe fn init( _world: &World, _state: &Self::State, _last_change_tick: u32, _change_tick: u32, ) -> Self { Self { state: PhantomData } } #[inline(always)] unsafe fn set_archetype( &mut self, _state: &Self::State, _archetype: &Archetype, _tables: &Tables, ) { } #[inline(always)] unsafe fn set_table(&mut self, _state: &Self::State, _table: &Table) {} #[inline(always)] unsafe fn archetype_fetch(&mut self, _archetype_index: usize) -> Self::Item {} #[inline(always)] unsafe fn table_fetch(&mut self, _table_row: usize) -> Self::Item {} }