mirror of
https://github.com/bevyengine/bevy
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ea42d14344
# Objective Expand the existing `Query` API to support more dynamic use cases i.e. scripting. ## Prior Art - #6390 - #8308 - #10037 ## Solution - Create a `QueryBuilder` with runtime methods to define the set of component accesses for a built query. - Create new `WorldQueryData` implementations `FilteredEntityMut` and `FilteredEntityRef` as variants of `EntityMut` and `EntityRef` that provide run time checked access to the components included in a given query. - Add new methods to `Query` to create "query lens" with a subset of the access of the initial query. ### Query Builder The `QueryBuilder` API allows you to define a query at runtime. At it's most basic use it will simply create a query with the corresponding type signature: ```rust let query = QueryBuilder::<Entity, With<A>>::new(&mut world).build(); // is equivalent to let query = QueryState::<Entity, With<A>>::new(&mut world); ``` Before calling `.build()` you also have the opportunity to add additional accesses and filters. Here is a simple example where we add additional filter terms: ```rust let entity_a = world.spawn((A(0), B(0))).id(); let entity_b = world.spawn((A(0), C(0))).id(); let mut query_a = QueryBuilder::<Entity>::new(&mut world) .with::<A>() .without::<C>() .build(); assert_eq!(entity_a, query_a.single(&world)); ``` This alone is useful in that allows you to decide which archetypes your query will match at runtime. However it is also very limited, consider a case like the following: ```rust let query_a = QueryBuilder::<&A>::new(&mut world) // Add an additional access .data::<&B>() .build(); ``` This will grant the query an additional read access to component B however we have no way of accessing the data while iterating as the type signature still only includes &A. For an even more concrete example of this consider dynamic components: ```rust let query_a = QueryBuilder::<Entity>::new(&mut world) // Adding a filter is easy since it doesn't need be read later .with_id(component_id_a) // How do I access the data of this component? .ref_id(component_id_b) .build(); ``` With this in mind the `QueryBuilder` API seems somewhat incomplete by itself, we need some way method of accessing the components dynamically. So here's one: ### Query Transmutation If the problem is not having the component in the type signature why not just add it? This PR also adds transmute methods to `QueryBuilder` and `QueryState`. Here's a simple example: ```rust world.spawn(A(0)); world.spawn((A(1), B(0))); let mut query = QueryBuilder::<()>::new(&mut world) .with::<B>() .transmute::<&A>() .build(); query.iter(&world).for_each(|a| assert_eq!(a.0, 1)); ``` The `QueryState` and `QueryBuilder` transmute methods look quite similar but are different in one respect. Transmuting a builder will always succeed as it will just add the additional accesses needed for the new terms if they weren't already included. Transmuting a `QueryState` will panic in the case that the new type signature would give it access it didn't already have, for example: ```rust let query = QueryState::<&A, Option<&B>>::new(&mut world); /// This is fine, the access for Option<&A> is less restrictive than &A query.transmute::<Option<&A>>(&world); /// Oh no, this would allow access to &B on entities that might not have it, so it panics query.transmute::<&B>(&world); /// This is right out query.transmute::<&C>(&world); ``` This is quite an appealing API to also have available on `Query` however it does pose one additional wrinkle: In order to to change the iterator we need to create a new `QueryState` to back it. `Query` doesn't own it's own state though, it just borrows it, so we need a place to borrow it from. This is why `QueryLens` exists, it is a place to store the new state so it can be borrowed when you call `.query()` leaving you with an API like this: ```rust fn function_that_takes_a_query(query: &Query<&A>) { // ... } fn system(query: Query<(&A, &B)>) { let lens = query.transmute_lens::<&A>(); let q = lens.query(); function_that_takes_a_query(&q); } ``` Now you may be thinking: Hey, wait a second, you introduced the problem with dynamic components and then described a solution that only works for static components! Ok, you got me, I guess we need a bit more: ### Filtered Entity References Currently the only way you can access dynamic components on entities through a query is with either `EntityMut` or `EntityRef`, however these can access all components and so conflict with all other accesses. This PR introduces `FilteredEntityMut` and `FilteredEntityRef` as alternatives that have additional runtime checking to prevent accessing components that you shouldn't. This way you can build a query with a `QueryBuilder` and actually access the components you asked for: ```rust let mut query = QueryBuilder::<FilteredEntityRef>::new(&mut world) .ref_id(component_id_a) .with(component_id_b) .build(); let entity_ref = query.single(&world); // Returns Some(Ptr) as we have that component and are allowed to read it let a = entity_ref.get_by_id(component_id_a); // Will return None even though the entity does have the component, as we are not allowed to read it let b = entity_ref.get_by_id(component_id_b); ``` For the most part these new structs have the exact same methods as their non-filtered equivalents. Putting all of this together we can do some truly dynamic ECS queries, check out the `dynamic` example to see it in action: ``` Commands: comp, c Create new components spawn, s Spawn entities query, q Query for entities Enter a command with no parameters for usage. > c A, B, C, Data 4 Component A created with id: 0 Component B created with id: 1 Component C created with id: 2 Component Data created with id: 3 > s A, B, Data 1 Entity spawned with id: 0v0 > s A, C, Data 0 Entity spawned with id: 1v0 > q &Data 0v0: Data: [1, 0, 0, 0] 1v0: Data: [0, 0, 0, 0] > q B, &mut Data 0v0: Data: [2, 1, 1, 1] > q B || C, &Data 0v0: Data: [2, 1, 1, 1] 1v0: Data: [0, 0, 0, 0] ``` ## Changelog - Add new `transmute_lens` methods to `Query`. - Add new types `QueryBuilder`, `FilteredEntityMut`, `FilteredEntityRef` and `QueryLens` - `update_archetype_component_access` has been removed, archetype component accesses are now determined by the accesses set in `update_component_access` - Added method `set_access` to `WorldQuery`, this is called before `update_component_access` for queries that have a restricted set of accesses, such as those built by `QueryBuilder` or `QueryLens`. This is primarily used by the `FilteredEntity*` variants and has an empty trait implementation. - Added method `get_state` to `WorldQuery` as a fallible version of `init_state` when you don't have `&mut World` access. ## Future Work Improve performance of `FilteredEntityMut` and `FilteredEntityRef`, currently they have to determine the accesses a query has in a given archetype during iteration which is far from ideal, especially since we already did the work when matching the archetype in the first place. To avoid making more internal API changes I have left it out of this PR. --------- Co-authored-by: Mike Hsu <mike.hsu@gmail.com>
1664 lines
60 KiB
Rust
1664 lines
60 KiB
Rust
use crate::{
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component::{Component, Tick},
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entity::Entity,
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query::{
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BatchingStrategy, QueryCombinationIter, QueryComponentError, QueryData, QueryEntityError,
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QueryFilter, QueryIter, QueryManyIter, QueryParIter, QuerySingleError, QueryState,
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ROQueryItem, ReadOnlyQueryData,
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},
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world::{unsafe_world_cell::UnsafeWorldCell, Mut},
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};
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use std::{any::TypeId, borrow::Borrow};
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/// [System parameter] that provides selective access to the [`Component`] data stored in a [`World`].
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///
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/// Enables access to [entity identifiers] and [components] from a system, without the need to directly access the world.
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/// Its iterators and getter methods return *query items*.
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/// Each query item is a type containing data relative to an entity.
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///
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/// `Query` is a generic data structure that accepts two type parameters:
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///
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/// - **`D` (query data).**
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/// The type of data contained in the query item.
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/// Only entities that match the requested data will generate an item.
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/// Must implement the [`QueryData`] trait.
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/// - **`F` (query filter).**
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/// A set of conditions that determines whether query items should be kept or discarded.
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/// Must implement the [`QueryFilter`] trait.
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/// This type parameter is optional.
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///
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/// [`World`]: crate::world::World
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///
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/// # System parameter declaration
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///
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/// A query should always be declared as a system parameter.
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/// This section shows the most common idioms involving the declaration of `Query`.
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///
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/// ## Component access
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///
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/// A query defined with a reference to a component as the query fetch type parameter can be used to generate items that refer to the data of said component.
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///
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/// ```
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/// # use bevy_ecs::prelude::*;
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/// # #[derive(Component)]
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/// # struct ComponentA;
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/// # fn immutable_ref(
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/// // A component can be accessed by shared reference...
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/// query: Query<&ComponentA>
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/// # ) {}
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/// # bevy_ecs::system::assert_is_system(immutable_ref);
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///
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/// # fn mutable_ref(
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/// // ... or by mutable reference.
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/// query: Query<&mut ComponentA>
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/// # ) {}
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/// # bevy_ecs::system::assert_is_system(mutable_ref);
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/// ```
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///
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/// ## Query filtering
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///
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/// Setting the query filter type parameter will ensure that each query item satisfies the given condition.
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///
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/// ```
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/// # use bevy_ecs::prelude::*;
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/// # #[derive(Component)]
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/// # struct ComponentA;
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/// # #[derive(Component)]
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/// # struct ComponentB;
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/// # fn system(
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/// // Just `ComponentA` data will be accessed, but only for entities that also contain
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/// // `ComponentB`.
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/// query: Query<&ComponentA, With<ComponentB>>
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/// # ) {}
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/// # bevy_ecs::system::assert_is_system(system);
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/// ```
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///
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/// ## `QueryData` or `QueryFilter` tuples
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///
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/// Using tuples, each `Query` type parameter can contain multiple elements.
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///
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/// In the following example, two components are accessed simultaneously, and the query items are filtered on two conditions.
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///
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/// ```
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/// # use bevy_ecs::prelude::*;
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/// # #[derive(Component)]
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/// # struct ComponentA;
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/// # #[derive(Component)]
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/// # struct ComponentB;
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/// # #[derive(Component)]
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/// # struct ComponentC;
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/// # #[derive(Component)]
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/// # struct ComponentD;
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/// # fn immutable_ref(
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/// query: Query<(&ComponentA, &ComponentB), (With<ComponentC>, Without<ComponentD>)>
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/// # ) {}
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/// # bevy_ecs::system::assert_is_system(immutable_ref);
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/// ```
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///
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/// ## Entity identifier access
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///
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/// The identifier of an entity can be made available inside the query item by including [`Entity`] in the query fetch type parameter.
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///
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/// ```
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/// # use bevy_ecs::prelude::*;
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/// # #[derive(Component)]
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/// # struct ComponentA;
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/// # fn system(
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/// query: Query<(Entity, &ComponentA)>
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/// # ) {}
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/// # bevy_ecs::system::assert_is_system(system);
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/// ```
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///
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/// ## Optional component access
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///
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/// A component can be made optional in a query by wrapping it into an [`Option`].
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/// In this way, a query item can still be generated even if the queried entity does not contain the wrapped component.
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/// In this case, its corresponding value will be `None`.
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///
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/// ```
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/// # use bevy_ecs::prelude::*;
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/// # #[derive(Component)]
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/// # struct ComponentA;
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/// # #[derive(Component)]
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/// # struct ComponentB;
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/// # fn system(
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/// // Generates items for entities that contain `ComponentA`, and optionally `ComponentB`.
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/// query: Query<(&ComponentA, Option<&ComponentB>)>
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/// # ) {}
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/// # bevy_ecs::system::assert_is_system(system);
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/// ```
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///
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/// See the documentation for [`AnyOf`] to idiomatically declare many optional components.
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///
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/// See the [performance] section to learn more about the impact of optional components.
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///
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/// ## Disjoint queries
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///
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/// A system cannot contain two queries that break Rust's mutability rules.
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/// In this case, the [`Without`] filter can be used to disjoint them.
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///
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/// In the following example, two queries mutably access the same component.
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/// Executing this system will panic, since an entity could potentially match the two queries at the same time by having both `Player` and `Enemy` components.
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/// This would violate mutability rules.
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///
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/// ```should_panic
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/// # use bevy_ecs::prelude::*;
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/// # #[derive(Component)]
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/// # struct Health;
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/// # #[derive(Component)]
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/// # struct Player;
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/// # #[derive(Component)]
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/// # struct Enemy;
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/// #
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/// fn randomize_health(
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/// player_query: Query<&mut Health, With<Player>>,
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/// enemy_query: Query<&mut Health, With<Enemy>>,
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/// )
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/// # {}
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/// # let mut randomize_health_system = IntoSystem::into_system(randomize_health);
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/// # let mut world = World::new();
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/// # randomize_health_system.initialize(&mut world);
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/// # randomize_health_system.run((), &mut world);
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/// ```
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///
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/// Adding a `Without` filter will disjoint the queries.
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/// In this way, any entity that has both `Player` and `Enemy` components is excluded from both queries.
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///
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/// ```
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/// # use bevy_ecs::prelude::*;
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/// # #[derive(Component)]
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/// # struct Health;
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/// # #[derive(Component)]
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/// # struct Player;
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/// # #[derive(Component)]
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/// # struct Enemy;
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/// #
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/// fn randomize_health(
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/// player_query: Query<&mut Health, (With<Player>, Without<Enemy>)>,
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/// enemy_query: Query<&mut Health, (With<Enemy>, Without<Player>)>,
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/// )
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/// # {}
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/// # let mut randomize_health_system = IntoSystem::into_system(randomize_health);
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/// # let mut world = World::new();
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/// # randomize_health_system.initialize(&mut world);
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/// # randomize_health_system.run((), &mut world);
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/// ```
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///
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/// An alternative to this idiom is to wrap the conflicting queries into a [`ParamSet`](super::ParamSet).
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///
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/// ## Whole Entity Access
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///
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/// [`EntityRef`]s can be fetched from a query. This will give read-only access to any component on the entity,
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/// and can be use to dynamically fetch any component without baking it into the query type. Due to this global
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/// access to the entity, this will block any other system from parallelizing with it. As such these queries
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/// should be sparingly used.
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///
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/// ```
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/// # use bevy_ecs::prelude::*;
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/// # #[derive(Component)]
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/// # struct ComponentA;
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/// # fn system(
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/// query: Query<(EntityRef, &ComponentA)>
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/// # ) {}
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/// # bevy_ecs::system::assert_is_system(system);
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/// ```
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///
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/// As `EntityRef` can read any component on an entity, a query using it will conflict with *any* mutable
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/// access. It is strongly advised to couple `EntityRef` queries with the use of either `With`/`Without`
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/// filters or `ParamSets`. This also limits the scope of the query, which will improve iteration performance
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/// and also allows it to parallelize with other non-conflicting systems.
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///
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/// ```should_panic
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/// # use bevy_ecs::prelude::*;
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/// # #[derive(Component)]
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/// # struct ComponentA;
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/// # fn system(
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/// // This will panic!
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/// query: Query<(EntityRef, &mut ComponentA)>
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/// # ) {}
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/// # bevy_ecs::system::assert_system_does_not_conflict(system);
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/// ```
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/// ```
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/// # use bevy_ecs::prelude::*;
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/// # #[derive(Component)]
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/// # struct ComponentA;
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/// # #[derive(Component)]
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/// # struct ComponentB;
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/// # fn system(
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/// // This will not panic.
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/// query_a: Query<EntityRef, With<ComponentA>>,
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/// query_b: Query<&mut ComponentB, Without<ComponentA>>,
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/// # ) {}
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/// # bevy_ecs::system::assert_system_does_not_conflict(system);
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/// ```
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///
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/// # Accessing query items
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///
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/// The following table summarizes the behavior of the safe methods that can be used to get query items.
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///
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/// |Query methods|Effect|
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/// |:---:|---|
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/// |[`iter`]\[[`_mut`][`iter_mut`]]|Returns an iterator over all query items.|
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/// |[`for_each`]\[[`_mut`][`for_each_mut`]],<br>[`par_iter`]\[[`_mut`][`par_iter_mut`]]|Runs a specified function for each query item.|
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/// |[`iter_many`]\[[`_mut`][`iter_many_mut`]]|Iterates or runs a specified function over query items generated by a list of entities.|
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/// |[`iter_combinations`]\[[`_mut`][`iter_combinations_mut`]]|Returns an iterator over all combinations of a specified number of query items.|
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/// |[`get`]\[[`_mut`][`get_mut`]]|Returns the query item for the specified entity.|
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/// |[`many`]\[[`_mut`][`many_mut`]],<br>[`get_many`]\[[`_mut`][`get_many_mut`]]|Returns the query items for the specified entities.|
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/// |[`single`]\[[`_mut`][`single_mut`]],<br>[`get_single`]\[[`_mut`][`get_single_mut`]]|Returns the query item while verifying that there aren't others.|
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///
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/// There are two methods for each type of query operation: immutable and mutable (ending with `_mut`).
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/// When using immutable methods, the query items returned are of type [`ROQueryItem`], a read-only version of the query item.
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/// In this circumstance, every mutable reference in the query fetch type parameter is substituted by a shared reference.
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///
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/// # Performance
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///
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/// Creating a `Query` is a low-cost constant operation.
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/// Iterating it, on the other hand, fetches data from the world and generates items, which can have a significant computational cost.
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///
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/// [`Table`] component storage type is much more optimized for query iteration than [`SparseSet`].
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///
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/// Two systems cannot be executed in parallel if both access the same component type where at least one of the accesses is mutable.
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/// This happens unless the executor can verify that no entity could be found in both queries.
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///
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/// Optional components increase the number of entities a query has to match against.
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/// This can hurt iteration performance, especially if the query solely consists of only optional components, since the query would iterate over each entity in the world.
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///
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/// The following table compares the computational complexity of the various methods and operations, where:
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///
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/// - **n** is the number of entities that match the query,
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/// - **r** is the number of elements in a combination,
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/// - **k** is the number of involved entities in the operation,
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/// - **a** is the number of archetypes in the world,
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/// - **C** is the [binomial coefficient], used to count combinations.
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/// <sub>n</sub>C<sub>r</sub> is read as "*n* choose *r*" and is equivalent to the number of distinct unordered subsets of *r* elements that can be taken from a set of *n* elements.
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///
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/// |Query operation|Computational complexity|
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/// |:---:|:---:|
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/// |[`iter`]\[[`_mut`][`iter_mut`]]|O(n)|
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/// |[`for_each`]\[[`_mut`][`for_each_mut`]],<br>[`par_iter`]\[[`_mut`][`par_iter_mut`]]|O(n)|
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/// |[`iter_many`]\[[`_mut`][`iter_many_mut`]]|O(k)|
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/// |[`iter_combinations`]\[[`_mut`][`iter_combinations_mut`]]|O(<sub>n</sub>C<sub>r</sub>)|
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/// |[`get`]\[[`_mut`][`get_mut`]]|O(1)|
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/// |([`get_`][`get_many`])[`many`]|O(k)|
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/// |([`get_`][`get_many_mut`])[`many_mut`]|O(k<sup>2</sup>)|
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/// |[`single`]\[[`_mut`][`single_mut`]],<br>[`get_single`]\[[`_mut`][`get_single_mut`]]|O(a)|
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/// |Archetype based filtering ([`With`], [`Without`], [`Or`])|O(a)|
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/// |Change detection filtering ([`Added`], [`Changed`])|O(a + n)|
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///
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/// `for_each` methods are seen to be generally faster than their `iter` version on worlds with high archetype fragmentation.
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/// As iterators are in general more flexible and better integrated with the rest of the Rust ecosystem,
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/// it is advised to use `iter` methods over `for_each`.
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/// It is strongly advised to only use `for_each` if it tangibly improves performance:
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/// be sure profile or benchmark both before and after the change.
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///
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/// [`Added`]: crate::query::Added
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/// [`AnyOf`]: crate::query::AnyOf
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/// [binomial coefficient]: https://en.wikipedia.org/wiki/Binomial_coefficient
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/// [`Changed`]: crate::query::Changed
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/// [components]: crate::component::Component
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/// [entity identifiers]: Entity
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/// [`EntityRef`]: crate::world::EntityRef
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/// [`for_each`]: Self::for_each
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/// [`for_each_mut`]: Self::for_each_mut
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/// [`get`]: Self::get
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/// [`get_many`]: Self::get_many
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/// [`get_many_mut`]: Self::get_many_mut
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/// [`get_mut`]: Self::get_mut
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/// [`get_single`]: Self::get_single
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/// [`get_single_mut`]: Self::get_single_mut
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/// [`iter`]: Self::iter
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/// [`iter_combinations`]: Self::iter_combinations
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/// [`iter_combinations_mut`]: Self::iter_combinations_mut
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/// [`iter_many`]: Self::iter_many
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/// [`iter_many_mut`]: Self::iter_many_mut
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/// [`iter_mut`]: Self::iter_mut
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/// [`many`]: Self::many
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/// [`many_mut`]: Self::many_mut
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/// [`Or`]: crate::query::Or
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|
/// [`par_iter`]: Self::par_iter
|
|
/// [`par_iter_mut`]: Self::par_iter_mut
|
|
/// [performance]: #performance
|
|
/// [`single`]: Self::single
|
|
/// [`single_mut`]: Self::single_mut
|
|
/// [`SparseSet`]: crate::storage::SparseSet
|
|
/// [System parameter]: crate::system::SystemParam
|
|
/// [`Table`]: crate::storage::Table
|
|
/// [`With`]: crate::query::With
|
|
/// [`Without`]: crate::query::Without
|
|
pub struct Query<'world, 'state, D: QueryData, F: QueryFilter = ()> {
|
|
// SAFETY: Must have access to the components registered in `state`.
|
|
world: UnsafeWorldCell<'world>,
|
|
state: &'state QueryState<D, F>,
|
|
last_run: Tick,
|
|
this_run: Tick,
|
|
// SAFETY: This is used to ensure that `get_component_mut::<C>` properly fails when a Query writes C
|
|
// and gets converted to a read-only query using `to_readonly`. Without checking this, `get_component_mut` relies on
|
|
// QueryState's archetype_component_access, which will continue allowing write access to C after being cast to
|
|
// the read-only variant. This whole situation is confusing and error prone. Ideally this is a temporary hack
|
|
// until we sort out a cleaner alternative.
|
|
force_read_only_component_access: bool,
|
|
}
|
|
|
|
impl<D: QueryData, F: QueryFilter> std::fmt::Debug for Query<'_, '_, D, F> {
|
|
fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
|
|
f.debug_struct("Query")
|
|
.field("matched_entities", &self.iter().count())
|
|
.field("state", &self.state)
|
|
.field("last_run", &self.last_run)
|
|
.field("this_run", &self.this_run)
|
|
.field("world", &self.world)
|
|
.finish()
|
|
}
|
|
}
|
|
|
|
impl<'w, 's, D: QueryData, F: QueryFilter> Query<'w, 's, D, F> {
|
|
/// Creates a new query.
|
|
///
|
|
/// # Panics
|
|
///
|
|
/// This will panic if the world used to create `state` is not `world`.
|
|
///
|
|
/// # Safety
|
|
///
|
|
/// This will create a query that could violate memory safety rules. Make sure that this is only
|
|
/// called in ways that ensure the queries have unique mutable access.
|
|
#[inline]
|
|
pub(crate) unsafe fn new(
|
|
world: UnsafeWorldCell<'w>,
|
|
state: &'s QueryState<D, F>,
|
|
last_run: Tick,
|
|
this_run: Tick,
|
|
force_read_only_component_access: bool,
|
|
) -> Self {
|
|
state.validate_world(world.id());
|
|
|
|
Self {
|
|
force_read_only_component_access,
|
|
world,
|
|
state,
|
|
last_run,
|
|
this_run,
|
|
}
|
|
}
|
|
|
|
/// Returns another `Query` from this that fetches the read-only version of the query items.
|
|
///
|
|
/// For example, `Query<(&mut D1, &D2, &mut D3), With<F>>` will become `Query<(&D1, &D2, &D3), With<F>>`.
|
|
/// This can be useful when working around the borrow checker,
|
|
/// or reusing functionality between systems via functions that accept query types.
|
|
pub fn to_readonly(&self) -> Query<'_, 's, D::ReadOnly, F> {
|
|
let new_state = self.state.as_readonly();
|
|
// SAFETY: This is memory safe because it turns the query immutable.
|
|
unsafe {
|
|
Query::new(
|
|
self.world,
|
|
new_state,
|
|
self.last_run,
|
|
self.this_run,
|
|
// SAFETY: this must be set to true or `get_component_mut` will be unsound. See the comments
|
|
// on this field for more details
|
|
true,
|
|
)
|
|
}
|
|
}
|
|
|
|
/// Returns an [`Iterator`] over the read-only query items.
|
|
///
|
|
/// # Example
|
|
///
|
|
/// Here, the `report_names_system` iterates over the `Player` component of every entity that contains it:
|
|
///
|
|
/// ```
|
|
/// # use bevy_ecs::prelude::*;
|
|
/// #
|
|
/// # #[derive(Component)]
|
|
/// # struct Player { name: String }
|
|
/// #
|
|
/// fn report_names_system(query: Query<&Player>) {
|
|
/// for player in &query {
|
|
/// println!("Say hello to {}!", player.name);
|
|
/// }
|
|
/// }
|
|
/// # bevy_ecs::system::assert_is_system(report_names_system);
|
|
/// ```
|
|
///
|
|
/// # See also
|
|
///
|
|
/// - [`iter_mut`](Self::iter_mut) for mutable query items.
|
|
/// - [`for_each`](Self::for_each) for the closure based alternative.
|
|
#[inline]
|
|
pub fn iter(&self) -> QueryIter<'_, 's, D::ReadOnly, F> {
|
|
// SAFETY:
|
|
// - `self.world` has permission to access the required components.
|
|
// - The query is read-only, so it can be aliased even if it was originally mutable.
|
|
unsafe {
|
|
self.state
|
|
.as_readonly()
|
|
.iter_unchecked_manual(self.world, self.last_run, self.this_run)
|
|
}
|
|
}
|
|
|
|
/// Returns an [`Iterator`] over the query items.
|
|
///
|
|
/// # Example
|
|
///
|
|
/// Here, the `gravity_system` updates the `Velocity` component of every entity that contains it:
|
|
///
|
|
/// ```
|
|
/// # use bevy_ecs::prelude::*;
|
|
/// #
|
|
/// # #[derive(Component)]
|
|
/// # struct Velocity { x: f32, y: f32, z: f32 }
|
|
/// fn gravity_system(mut query: Query<&mut Velocity>) {
|
|
/// const DELTA: f32 = 1.0 / 60.0;
|
|
/// for mut velocity in &mut query {
|
|
/// velocity.y -= 9.8 * DELTA;
|
|
/// }
|
|
/// }
|
|
/// # bevy_ecs::system::assert_is_system(gravity_system);
|
|
/// ```
|
|
///
|
|
/// # See also
|
|
///
|
|
/// - [`iter`](Self::iter) for read-only query items.
|
|
/// - [`for_each_mut`](Self::for_each_mut) for the closure based alternative.
|
|
#[inline]
|
|
pub fn iter_mut(&mut self) -> QueryIter<'_, 's, D, F> {
|
|
// SAFETY: `self.world` has permission to access the required components.
|
|
unsafe {
|
|
self.state
|
|
.iter_unchecked_manual(self.world, self.last_run, self.this_run)
|
|
}
|
|
}
|
|
|
|
/// Returns a [`QueryCombinationIter`] over all combinations of `K` read-only query items without repetition.
|
|
///
|
|
/// # Example
|
|
///
|
|
/// ```
|
|
/// # use bevy_ecs::prelude::*;
|
|
/// # #[derive(Component)]
|
|
/// # struct ComponentA;
|
|
/// #
|
|
/// fn some_system(query: Query<&ComponentA>) {
|
|
/// for [a1, a2] in query.iter_combinations() {
|
|
/// // ...
|
|
/// }
|
|
/// }
|
|
/// ```
|
|
///
|
|
/// # See also
|
|
///
|
|
/// - [`iter_combinations_mut`](Self::iter_combinations_mut) for mutable query item combinations.
|
|
#[inline]
|
|
pub fn iter_combinations<const K: usize>(
|
|
&self,
|
|
) -> QueryCombinationIter<'_, 's, D::ReadOnly, F, K> {
|
|
// SAFETY:
|
|
// - `self.world` has permission to access the required components.
|
|
// - The query is read-only, so it can be aliased even if it was originally mutable.
|
|
unsafe {
|
|
self.state.as_readonly().iter_combinations_unchecked_manual(
|
|
self.world,
|
|
self.last_run,
|
|
self.this_run,
|
|
)
|
|
}
|
|
}
|
|
|
|
/// Returns a [`QueryCombinationIter`] over all combinations of `K` query items without repetition.
|
|
///
|
|
/// # Example
|
|
///
|
|
/// ```
|
|
/// # use bevy_ecs::prelude::*;
|
|
/// # #[derive(Component)]
|
|
/// # struct ComponentA;
|
|
/// fn some_system(mut query: Query<&mut ComponentA>) {
|
|
/// let mut combinations = query.iter_combinations_mut();
|
|
/// while let Some([mut a1, mut a2]) = combinations.fetch_next() {
|
|
/// // mutably access components data
|
|
/// }
|
|
/// }
|
|
/// ```
|
|
///
|
|
/// # See also
|
|
///
|
|
/// - [`iter_combinations`](Self::iter_combinations) for read-only query item combinations.
|
|
#[inline]
|
|
pub fn iter_combinations_mut<const K: usize>(
|
|
&mut self,
|
|
) -> QueryCombinationIter<'_, 's, D, F, K> {
|
|
// SAFETY: `self.world` has permission to access the required components.
|
|
unsafe {
|
|
self.state
|
|
.iter_combinations_unchecked_manual(self.world, self.last_run, self.this_run)
|
|
}
|
|
}
|
|
|
|
/// Returns an [`Iterator`] over the read-only query items generated from an [`Entity`] list.
|
|
///
|
|
/// Items are returned in the order of the list of entities.
|
|
/// Entities that don't match the query are skipped.
|
|
///
|
|
/// # Example
|
|
///
|
|
/// ```
|
|
/// # use bevy_ecs::prelude::*;
|
|
/// # #[derive(Component)]
|
|
/// # struct Counter {
|
|
/// # value: i32
|
|
/// # }
|
|
/// #
|
|
/// // A component containing an entity list.
|
|
/// #[derive(Component)]
|
|
/// struct Friends {
|
|
/// list: Vec<Entity>,
|
|
/// }
|
|
///
|
|
/// fn system(
|
|
/// friends_query: Query<&Friends>,
|
|
/// counter_query: Query<&Counter>,
|
|
/// ) {
|
|
/// for friends in &friends_query {
|
|
/// for counter in counter_query.iter_many(&friends.list) {
|
|
/// println!("Friend's counter: {:?}", counter.value);
|
|
/// }
|
|
/// }
|
|
/// }
|
|
/// # bevy_ecs::system::assert_is_system(system);
|
|
/// ```
|
|
///
|
|
/// # See also
|
|
///
|
|
/// - [`iter_many_mut`](Self::iter_many_mut) to get mutable query items.
|
|
#[inline]
|
|
pub fn iter_many<EntityList: IntoIterator>(
|
|
&self,
|
|
entities: EntityList,
|
|
) -> QueryManyIter<'_, 's, D::ReadOnly, F, EntityList::IntoIter>
|
|
where
|
|
EntityList::Item: Borrow<Entity>,
|
|
{
|
|
// SAFETY:
|
|
// - `self.world` has permission to access the required components.
|
|
// - The query is read-only, so it can be aliased even if it was originally mutable.
|
|
unsafe {
|
|
self.state.as_readonly().iter_many_unchecked_manual(
|
|
entities,
|
|
self.world,
|
|
self.last_run,
|
|
self.this_run,
|
|
)
|
|
}
|
|
}
|
|
|
|
/// Returns an iterator over the query items generated from an [`Entity`] list.
|
|
///
|
|
/// Items are returned in the order of the list of entities.
|
|
/// Entities that don't match the query are skipped.
|
|
///
|
|
/// # Examples
|
|
///
|
|
/// ```
|
|
/// # use bevy_ecs::prelude::*;
|
|
/// #[derive(Component)]
|
|
/// struct Counter {
|
|
/// value: i32
|
|
/// }
|
|
///
|
|
/// #[derive(Component)]
|
|
/// struct Friends {
|
|
/// list: Vec<Entity>,
|
|
/// }
|
|
///
|
|
/// fn system(
|
|
/// friends_query: Query<&Friends>,
|
|
/// mut counter_query: Query<&mut Counter>,
|
|
/// ) {
|
|
/// for friends in &friends_query {
|
|
/// let mut iter = counter_query.iter_many_mut(&friends.list);
|
|
/// while let Some(mut counter) = iter.fetch_next() {
|
|
/// println!("Friend's counter: {:?}", counter.value);
|
|
/// counter.value += 1;
|
|
/// }
|
|
/// }
|
|
/// }
|
|
/// # bevy_ecs::system::assert_is_system(system);
|
|
/// ```
|
|
#[inline]
|
|
pub fn iter_many_mut<EntityList: IntoIterator>(
|
|
&mut self,
|
|
entities: EntityList,
|
|
) -> QueryManyIter<'_, 's, D, F, EntityList::IntoIter>
|
|
where
|
|
EntityList::Item: Borrow<Entity>,
|
|
{
|
|
// SAFETY: `self.world` has permission to access the required components.
|
|
unsafe {
|
|
self.state.iter_many_unchecked_manual(
|
|
entities,
|
|
self.world,
|
|
self.last_run,
|
|
self.this_run,
|
|
)
|
|
}
|
|
}
|
|
|
|
/// Returns an [`Iterator`] over the query items.
|
|
///
|
|
/// # Safety
|
|
///
|
|
/// This function makes it possible to violate Rust's aliasing guarantees.
|
|
/// You must make sure this call does not result in multiple mutable references to the same component.
|
|
///
|
|
/// # See also
|
|
///
|
|
/// - [`iter`](Self::iter) and [`iter_mut`](Self::iter_mut) for the safe versions.
|
|
#[inline]
|
|
pub unsafe fn iter_unsafe(&self) -> QueryIter<'_, 's, D, F> {
|
|
// SAFETY:
|
|
// - `self.world` has permission to access the required components.
|
|
// - The caller ensures that this operation will not result in any aliased mutable accesses.
|
|
self.state
|
|
.iter_unchecked_manual(self.world, self.last_run, self.this_run)
|
|
}
|
|
|
|
/// Iterates over all possible combinations of `K` query items without repetition.
|
|
///
|
|
/// # Safety
|
|
///
|
|
/// This allows aliased mutability.
|
|
/// You must make sure this call does not result in multiple mutable references to the same component.
|
|
///
|
|
/// # See also
|
|
///
|
|
/// - [`iter_combinations`](Self::iter_combinations) and [`iter_combinations_mut`](Self::iter_combinations_mut) for the safe versions.
|
|
#[inline]
|
|
pub unsafe fn iter_combinations_unsafe<const K: usize>(
|
|
&self,
|
|
) -> QueryCombinationIter<'_, 's, D, F, K> {
|
|
// SAFETY:
|
|
// - `self.world` has permission to access the required components.
|
|
// - The caller ensures that this operation will not result in any aliased mutable accesses.
|
|
self.state
|
|
.iter_combinations_unchecked_manual(self.world, self.last_run, self.this_run)
|
|
}
|
|
|
|
/// Returns an [`Iterator`] over the query items generated from an [`Entity`] list.
|
|
///
|
|
/// # Safety
|
|
///
|
|
/// This allows aliased mutability and does not check for entity uniqueness.
|
|
/// You must make sure this call does not result in multiple mutable references to the same component.
|
|
/// Particular care must be taken when collecting the data (rather than iterating over it one item at a time) such as via [`Iterator::collect`].
|
|
///
|
|
/// # See also
|
|
///
|
|
/// - [`iter_many_mut`](Self::iter_many_mut) to safely access the query items.
|
|
pub unsafe fn iter_many_unsafe<EntityList: IntoIterator>(
|
|
&self,
|
|
entities: EntityList,
|
|
) -> QueryManyIter<'_, 's, D, F, EntityList::IntoIter>
|
|
where
|
|
EntityList::Item: Borrow<Entity>,
|
|
{
|
|
// SAFETY:
|
|
// - `self.world` has permission to access the required components.
|
|
// - The caller ensures that this operation will not result in any aliased mutable accesses.
|
|
self.state
|
|
.iter_many_unchecked_manual(entities, self.world, self.last_run, self.this_run)
|
|
}
|
|
|
|
/// Runs `f` on each read-only query item.
|
|
///
|
|
/// Shorthand for `query.iter().for_each(..)`.
|
|
///
|
|
/// # Example
|
|
///
|
|
/// Here, the `report_names_system` iterates over the `Player` component of every entity that contains it:
|
|
///
|
|
/// ```
|
|
/// # use bevy_ecs::prelude::*;
|
|
/// #
|
|
/// # #[derive(Component)]
|
|
/// # struct Player { name: String }
|
|
/// #
|
|
/// fn report_names_system(query: Query<&Player>) {
|
|
/// query.for_each(|player| {
|
|
/// println!("Say hello to {}!", player.name);
|
|
/// });
|
|
/// }
|
|
/// # bevy_ecs::system::assert_is_system(report_names_system);
|
|
/// ```
|
|
///
|
|
/// # See also
|
|
///
|
|
/// - [`for_each_mut`](Self::for_each_mut) to operate on mutable query items.
|
|
/// - [`iter`](Self::iter) for the iterator based alternative.
|
|
#[inline]
|
|
#[deprecated(
|
|
since = "0.13.0",
|
|
note = "Query::for_each was not idiomatic Rust and has been moved to query.iter().for_each()"
|
|
)]
|
|
pub fn for_each<'this>(&'this self, f: impl FnMut(ROQueryItem<'this, D>)) {
|
|
// SAFETY:
|
|
// - `self.world` has permission to access the required components.
|
|
// - The query is read-only, so it can be aliased even if it was originally mutable.
|
|
unsafe {
|
|
self.state
|
|
.as_readonly()
|
|
.iter_unchecked_manual(self.world, self.last_run, self.this_run)
|
|
.for_each(f);
|
|
};
|
|
}
|
|
|
|
/// Runs `f` on each query item.
|
|
///
|
|
/// Shorthand for `query.iter_mut().for_each(..)`.
|
|
///
|
|
/// # Example
|
|
///
|
|
/// Here, the `gravity_system` updates the `Velocity` component of every entity that contains it:
|
|
///
|
|
/// ```
|
|
/// # use bevy_ecs::prelude::*;
|
|
/// #
|
|
/// # #[derive(Component)]
|
|
/// # struct Velocity { x: f32, y: f32, z: f32 }
|
|
/// fn gravity_system(mut query: Query<&mut Velocity>) {
|
|
/// const DELTA: f32 = 1.0 / 60.0;
|
|
/// query.for_each_mut(|mut velocity| {
|
|
/// velocity.y -= 9.8 * DELTA;
|
|
/// });
|
|
/// }
|
|
/// # bevy_ecs::system::assert_is_system(gravity_system);
|
|
/// ```
|
|
///
|
|
/// # See also
|
|
///
|
|
/// - [`for_each`](Self::for_each) to operate on read-only query items.
|
|
/// - [`iter_mut`](Self::iter_mut) for the iterator based alternative.
|
|
#[inline]
|
|
#[deprecated(
|
|
since = "0.13.0",
|
|
note = "Query::for_each_mut was not idiomatic Rust and has been moved to query.iter_mut().for_each()"
|
|
)]
|
|
pub fn for_each_mut<'a>(&'a mut self, f: impl FnMut(D::Item<'a>)) {
|
|
// SAFETY: `self.world` has permission to access the required components.
|
|
unsafe {
|
|
self.state
|
|
.iter_unchecked_manual(self.world, self.last_run, self.this_run)
|
|
.for_each(f);
|
|
};
|
|
}
|
|
|
|
/// Returns a parallel iterator over the query results for the given [`World`].
|
|
///
|
|
/// This can only be called for read-only queries, see [`par_iter_mut`] for write-queries.
|
|
///
|
|
/// [`par_iter_mut`]: Self::par_iter_mut
|
|
/// [`World`]: crate::world::World
|
|
#[inline]
|
|
pub fn par_iter(&self) -> QueryParIter<'_, '_, D::ReadOnly, F> {
|
|
QueryParIter {
|
|
world: self.world,
|
|
state: self.state.as_readonly(),
|
|
last_run: self.last_run,
|
|
this_run: self.this_run,
|
|
batching_strategy: BatchingStrategy::new(),
|
|
}
|
|
}
|
|
|
|
/// Returns a parallel iterator over the query results for the given [`World`].
|
|
///
|
|
/// This can only be called for mutable queries, see [`par_iter`] for read-only-queries.
|
|
///
|
|
/// [`par_iter`]: Self::par_iter
|
|
/// [`World`]: crate::world::World
|
|
#[inline]
|
|
pub fn par_iter_mut(&mut self) -> QueryParIter<'_, '_, D, F> {
|
|
QueryParIter {
|
|
world: self.world,
|
|
state: self.state,
|
|
last_run: self.last_run,
|
|
this_run: self.this_run,
|
|
batching_strategy: BatchingStrategy::new(),
|
|
}
|
|
}
|
|
|
|
/// Returns the read-only query item for the given [`Entity`].
|
|
///
|
|
/// In case of a nonexisting entity or mismatched component, a [`QueryEntityError`] is returned instead.
|
|
///
|
|
/// # Example
|
|
///
|
|
/// Here, `get` is used to retrieve the exact query item of the entity specified by the `SelectedCharacter` resource.
|
|
///
|
|
/// ```
|
|
/// # use bevy_ecs::prelude::*;
|
|
/// #
|
|
/// # #[derive(Resource)]
|
|
/// # struct SelectedCharacter { entity: Entity }
|
|
/// # #[derive(Component)]
|
|
/// # struct Character { name: String }
|
|
/// #
|
|
/// fn print_selected_character_name_system(
|
|
/// query: Query<&Character>,
|
|
/// selection: Res<SelectedCharacter>
|
|
/// )
|
|
/// {
|
|
/// if let Ok(selected_character) = query.get(selection.entity) {
|
|
/// println!("{}", selected_character.name);
|
|
/// }
|
|
/// }
|
|
/// # bevy_ecs::system::assert_is_system(print_selected_character_name_system);
|
|
/// ```
|
|
///
|
|
/// # See also
|
|
///
|
|
/// - [`get_mut`](Self::get_mut) to get a mutable query item.
|
|
#[inline]
|
|
pub fn get(&self, entity: Entity) -> Result<ROQueryItem<'_, D>, QueryEntityError> {
|
|
// SAFETY: system runs without conflicts with other systems.
|
|
// same-system queries have runtime borrow checks when they conflict
|
|
unsafe {
|
|
self.state.as_readonly().get_unchecked_manual(
|
|
self.world,
|
|
entity,
|
|
self.last_run,
|
|
self.this_run,
|
|
)
|
|
}
|
|
}
|
|
|
|
/// Returns the read-only query items for the given array of [`Entity`].
|
|
///
|
|
/// The returned query items are in the same order as the input.
|
|
/// In case of a nonexisting entity or mismatched component, a [`QueryEntityError`] is returned instead.
|
|
/// The elements of the array do not need to be unique, unlike `get_many_mut`.
|
|
///
|
|
/// # See also
|
|
///
|
|
/// - [`get_many_mut`](Self::get_many_mut) to get mutable query items.
|
|
/// - [`many`](Self::many) for the panicking version.
|
|
#[inline]
|
|
pub fn get_many<const N: usize>(
|
|
&self,
|
|
entities: [Entity; N],
|
|
) -> Result<[ROQueryItem<'_, D>; N], QueryEntityError> {
|
|
// SAFETY:
|
|
// - `&self` ensures there is no mutable access to any components accessible to this query.
|
|
// - `self.world` matches `self.state`.
|
|
unsafe {
|
|
self.state
|
|
.get_many_read_only_manual(self.world, entities, self.last_run, self.this_run)
|
|
}
|
|
}
|
|
|
|
/// Returns the read-only query items for the given array of [`Entity`].
|
|
///
|
|
/// # Panics
|
|
///
|
|
/// This method panics if there is a query mismatch or a non-existing entity.
|
|
///
|
|
/// # Examples
|
|
/// ``` no_run
|
|
/// use bevy_ecs::prelude::*;
|
|
///
|
|
/// #[derive(Component)]
|
|
/// struct Targets([Entity; 3]);
|
|
///
|
|
/// #[derive(Component)]
|
|
/// struct Position{
|
|
/// x: i8,
|
|
/// y: i8
|
|
/// };
|
|
///
|
|
/// impl Position {
|
|
/// fn distance(&self, other: &Position) -> i8 {
|
|
/// // Manhattan distance is way easier to compute!
|
|
/// (self.x - other.x).abs() + (self.y - other.y).abs()
|
|
/// }
|
|
/// }
|
|
///
|
|
/// fn check_all_targets_in_range(targeting_query: Query<(Entity, &Targets, &Position)>, targets_query: Query<&Position>){
|
|
/// for (targeting_entity, targets, origin) in &targeting_query {
|
|
/// // We can use "destructuring" to unpack the results nicely
|
|
/// let [target_1, target_2, target_3] = targets_query.many(targets.0);
|
|
///
|
|
/// assert!(target_1.distance(origin) <= 5);
|
|
/// assert!(target_2.distance(origin) <= 5);
|
|
/// assert!(target_3.distance(origin) <= 5);
|
|
/// }
|
|
/// }
|
|
/// ```
|
|
///
|
|
/// # See also
|
|
///
|
|
/// - [`get_many`](Self::get_many) for the non-panicking version.
|
|
#[inline]
|
|
pub fn many<const N: usize>(&self, entities: [Entity; N]) -> [ROQueryItem<'_, D>; N] {
|
|
match self.get_many(entities) {
|
|
Ok(items) => items,
|
|
Err(error) => panic!("Cannot get query results: {error}"),
|
|
}
|
|
}
|
|
|
|
/// Returns the query item for the given [`Entity`].
|
|
///
|
|
/// In case of a nonexisting entity or mismatched component, a [`QueryEntityError`] is returned instead.
|
|
///
|
|
/// # Example
|
|
///
|
|
/// Here, `get_mut` is used to retrieve the exact query item of the entity specified by the `PoisonedCharacter` resource.
|
|
///
|
|
/// ```
|
|
/// # use bevy_ecs::prelude::*;
|
|
/// #
|
|
/// # #[derive(Resource)]
|
|
/// # struct PoisonedCharacter { character_id: Entity }
|
|
/// # #[derive(Component)]
|
|
/// # struct Health(u32);
|
|
/// #
|
|
/// fn poison_system(mut query: Query<&mut Health>, poisoned: Res<PoisonedCharacter>) {
|
|
/// if let Ok(mut health) = query.get_mut(poisoned.character_id) {
|
|
/// health.0 -= 1;
|
|
/// }
|
|
/// }
|
|
/// # bevy_ecs::system::assert_is_system(poison_system);
|
|
/// ```
|
|
///
|
|
/// # See also
|
|
///
|
|
/// - [`get`](Self::get) to get a read-only query item.
|
|
#[inline]
|
|
pub fn get_mut(&mut self, entity: Entity) -> Result<D::Item<'_>, QueryEntityError> {
|
|
// SAFETY: system runs without conflicts with other systems.
|
|
// same-system queries have runtime borrow checks when they conflict
|
|
unsafe {
|
|
self.state
|
|
.get_unchecked_manual(self.world, entity, self.last_run, self.this_run)
|
|
}
|
|
}
|
|
|
|
/// Returns the query items for the given array of [`Entity`].
|
|
///
|
|
/// The returned query items are in the same order as the input.
|
|
/// In case of a nonexisting entity, duplicate entities or mismatched component, a [`QueryEntityError`] is returned instead.
|
|
///
|
|
/// # See also
|
|
///
|
|
/// - [`get_many`](Self::get_many) to get read-only query items.
|
|
/// - [`many_mut`](Self::many_mut) for the panicking version.
|
|
#[inline]
|
|
pub fn get_many_mut<const N: usize>(
|
|
&mut self,
|
|
entities: [Entity; N],
|
|
) -> Result<[D::Item<'_>; N], QueryEntityError> {
|
|
// SAFETY: scheduler ensures safe Query world access
|
|
unsafe {
|
|
self.state
|
|
.get_many_unchecked_manual(self.world, entities, self.last_run, self.this_run)
|
|
}
|
|
}
|
|
|
|
/// Returns the query items for the given array of [`Entity`].
|
|
///
|
|
/// # Panics
|
|
///
|
|
/// This method panics if there is a query mismatch, a non-existing entity, or the same `Entity` is included more than once in the array.
|
|
///
|
|
/// # Examples
|
|
///
|
|
/// ``` no_run
|
|
/// use bevy_ecs::prelude::*;
|
|
///
|
|
/// #[derive(Component)]
|
|
/// struct Spring{
|
|
/// connected_entities: [Entity; 2],
|
|
/// strength: f32,
|
|
/// }
|
|
///
|
|
/// #[derive(Component)]
|
|
/// struct Position {
|
|
/// x: f32,
|
|
/// y: f32,
|
|
/// }
|
|
///
|
|
/// #[derive(Component)]
|
|
/// struct Force {
|
|
/// x: f32,
|
|
/// y: f32,
|
|
/// }
|
|
///
|
|
/// fn spring_forces(spring_query: Query<&Spring>, mut mass_query: Query<(&Position, &mut Force)>){
|
|
/// for spring in &spring_query {
|
|
/// // We can use "destructuring" to unpack our query items nicely
|
|
/// let [(position_1, mut force_1), (position_2, mut force_2)] = mass_query.many_mut(spring.connected_entities);
|
|
///
|
|
/// force_1.x += spring.strength * (position_1.x - position_2.x);
|
|
/// force_1.y += spring.strength * (position_1.y - position_2.y);
|
|
///
|
|
/// // Silence borrow-checker: I have split your mutable borrow!
|
|
/// force_2.x += spring.strength * (position_2.x - position_1.x);
|
|
/// force_2.y += spring.strength * (position_2.y - position_1.y);
|
|
/// }
|
|
/// }
|
|
/// ```
|
|
///
|
|
/// # See also
|
|
///
|
|
/// - [`get_many_mut`](Self::get_many_mut) for the non panicking version.
|
|
/// - [`many`](Self::many) to get read-only query items.
|
|
#[inline]
|
|
pub fn many_mut<const N: usize>(&mut self, entities: [Entity; N]) -> [D::Item<'_>; N] {
|
|
match self.get_many_mut(entities) {
|
|
Ok(items) => items,
|
|
Err(error) => panic!("Cannot get query result: {error}"),
|
|
}
|
|
}
|
|
|
|
/// Returns the query item for the given [`Entity`].
|
|
///
|
|
/// In case of a nonexisting entity or mismatched component, a [`QueryEntityError`] is returned instead.
|
|
///
|
|
/// # Safety
|
|
///
|
|
/// This function makes it possible to violate Rust's aliasing guarantees.
|
|
/// You must make sure this call does not result in multiple mutable references to the same component.
|
|
///
|
|
/// # See also
|
|
///
|
|
/// - [`get_mut`](Self::get_mut) for the safe version.
|
|
#[inline]
|
|
pub unsafe fn get_unchecked(&self, entity: Entity) -> Result<D::Item<'_>, QueryEntityError> {
|
|
// SEMI-SAFETY: system runs without conflicts with other systems.
|
|
// same-system queries have runtime borrow checks when they conflict
|
|
self.state
|
|
.get_unchecked_manual(self.world, entity, self.last_run, self.this_run)
|
|
}
|
|
|
|
/// Returns a shared reference to the component `T` of the given [`Entity`].
|
|
///
|
|
/// In case of a nonexisting entity or mismatched component, a [`QueryEntityError`] is returned instead.
|
|
///
|
|
/// # Example
|
|
///
|
|
/// Here, `get_component` is used to retrieve the `Character` component of the entity specified by the `SelectedCharacter` resource.
|
|
///
|
|
/// ```
|
|
/// # use bevy_ecs::prelude::*;
|
|
/// #
|
|
/// # #[derive(Resource)]
|
|
/// # struct SelectedCharacter { entity: Entity }
|
|
/// # #[derive(Component)]
|
|
/// # struct Character { name: String }
|
|
/// #
|
|
/// fn print_selected_character_name_system(
|
|
/// query: Query<&Character>,
|
|
/// selection: Res<SelectedCharacter>
|
|
/// )
|
|
/// {
|
|
/// if let Ok(selected_character) = query.get_component::<Character>(selection.entity) {
|
|
/// println!("{}", selected_character.name);
|
|
/// }
|
|
/// }
|
|
/// # bevy_ecs::system::assert_is_system(print_selected_character_name_system);
|
|
/// ```
|
|
///
|
|
/// # See also
|
|
///
|
|
/// - [`component`](Self::component) a panicking version of this function.
|
|
/// - [`get_component_mut`](Self::get_component_mut) to get a mutable reference of a component.
|
|
#[inline]
|
|
pub fn get_component<T: Component>(&self, entity: Entity) -> Result<&T, QueryComponentError> {
|
|
self.state.get_component(self.world, entity)
|
|
}
|
|
|
|
/// Returns a mutable reference to the component `T` of the given entity.
|
|
///
|
|
/// In case of a nonexisting entity, mismatched component or missing write access, a [`QueryComponentError`] is returned instead.
|
|
///
|
|
/// # Example
|
|
///
|
|
/// Here, `get_component_mut` is used to retrieve the `Health` component of the entity specified by the `PoisonedCharacter` resource.
|
|
///
|
|
/// ```
|
|
/// # use bevy_ecs::prelude::*;
|
|
/// #
|
|
/// # #[derive(Resource)]
|
|
/// # struct PoisonedCharacter { character_id: Entity }
|
|
/// # #[derive(Component)]
|
|
/// # struct Health(u32);
|
|
/// #
|
|
/// fn poison_system(mut query: Query<&mut Health>, poisoned: Res<PoisonedCharacter>) {
|
|
/// if let Ok(mut health) = query.get_component_mut::<Health>(poisoned.character_id) {
|
|
/// health.0 -= 1;
|
|
/// }
|
|
/// }
|
|
/// # bevy_ecs::system::assert_is_system(poison_system);
|
|
/// ```
|
|
///
|
|
/// # See also
|
|
///
|
|
/// - [`component_mut`](Self::component_mut) a panicking version of this function.
|
|
/// - [`get_component`](Self::get_component) to get a shared reference of a component.
|
|
#[inline]
|
|
pub fn get_component_mut<T: Component>(
|
|
&mut self,
|
|
entity: Entity,
|
|
) -> Result<Mut<'_, T>, QueryComponentError> {
|
|
// SAFETY: unique access to query (preventing aliased access)
|
|
unsafe { self.get_component_unchecked_mut(entity) }
|
|
}
|
|
|
|
/// Returns a shared reference to the component `T` of the given [`Entity`].
|
|
///
|
|
/// # Panics
|
|
///
|
|
/// Panics in case of a nonexisting entity or mismatched component.
|
|
///
|
|
/// # See also
|
|
///
|
|
/// - [`get_component`](Self::get_component) a non-panicking version of this function.
|
|
/// - [`component_mut`](Self::component_mut) to get a mutable reference of a component.
|
|
#[inline]
|
|
#[track_caller]
|
|
pub fn component<T: Component>(&self, entity: Entity) -> &T {
|
|
self.state.component(self.world, entity)
|
|
}
|
|
|
|
/// Returns a mutable reference to the component `T` of the given entity.
|
|
///
|
|
/// # Panics
|
|
///
|
|
/// Panics in case of a nonexisting entity, mismatched component or missing write access.
|
|
///
|
|
/// # See also
|
|
///
|
|
/// - [`get_component_mut`](Self::get_component_mut) a non-panicking version of this function.
|
|
/// - [`component`](Self::component) to get a shared reference of a component.
|
|
#[inline]
|
|
#[track_caller]
|
|
pub fn component_mut<T: Component>(&mut self, entity: Entity) -> Mut<'_, T> {
|
|
match self.get_component_mut(entity) {
|
|
Ok(component) => component,
|
|
Err(error) => {
|
|
panic!(
|
|
"Cannot get component `{:?}` from {entity:?}: {error}",
|
|
TypeId::of::<T>()
|
|
)
|
|
}
|
|
}
|
|
}
|
|
|
|
/// Returns a mutable reference to the component `T` of the given entity.
|
|
///
|
|
/// In case of a nonexisting entity or mismatched component, a [`QueryComponentError`] is returned instead.
|
|
///
|
|
/// # Safety
|
|
///
|
|
/// This function makes it possible to violate Rust's aliasing guarantees.
|
|
/// You must make sure this call does not result in multiple mutable references to the same component.
|
|
///
|
|
/// # See also
|
|
///
|
|
/// - [`get_component_mut`](Self::get_component_mut) for the safe version.
|
|
#[inline]
|
|
pub unsafe fn get_component_unchecked_mut<T: Component>(
|
|
&self,
|
|
entity: Entity,
|
|
) -> Result<Mut<'_, T>, QueryComponentError> {
|
|
// This check is required to ensure soundness in the case of `to_readonly().get_component_mut()`
|
|
// See the comments on the `force_read_only_component_access` field for more info.
|
|
if self.force_read_only_component_access {
|
|
return Err(QueryComponentError::MissingWriteAccess);
|
|
}
|
|
|
|
// SAFETY: The above check ensures we are not a readonly query.
|
|
// It is the callers responsibility to ensure multiple mutable access is not provided.
|
|
unsafe {
|
|
self.state
|
|
.get_component_unchecked_mut(self.world, entity, self.last_run, self.this_run)
|
|
}
|
|
}
|
|
|
|
/// Returns a single read-only query item when there is exactly one entity matching the query.
|
|
///
|
|
/// # Panics
|
|
///
|
|
/// This method panics if the number of query items is **not** exactly one.
|
|
///
|
|
/// # Example
|
|
///
|
|
/// ```
|
|
/// # use bevy_ecs::prelude::*;
|
|
/// # #[derive(Component)]
|
|
/// # struct Player;
|
|
/// # #[derive(Component)]
|
|
/// # struct Position(f32, f32);
|
|
/// fn player_system(query: Query<&Position, With<Player>>) {
|
|
/// let player_position = query.single();
|
|
/// // do something with player_position
|
|
/// }
|
|
/// # bevy_ecs::system::assert_is_system(player_system);
|
|
/// ```
|
|
///
|
|
/// # See also
|
|
///
|
|
/// - [`get_single`](Self::get_single) for the non-panicking version.
|
|
/// - [`single_mut`](Self::single_mut) to get the mutable query item.
|
|
#[track_caller]
|
|
pub fn single(&self) -> ROQueryItem<'_, D> {
|
|
self.get_single().unwrap()
|
|
}
|
|
|
|
/// Returns a single read-only query item when there is exactly one entity matching the query.
|
|
///
|
|
/// If the number of query items is not exactly one, a [`QuerySingleError`] is returned instead.
|
|
///
|
|
/// # Example
|
|
///
|
|
/// ```
|
|
/// # use bevy_ecs::prelude::*;
|
|
/// # use bevy_ecs::query::QuerySingleError;
|
|
/// # #[derive(Component)]
|
|
/// # struct PlayerScore(i32);
|
|
/// fn player_scoring_system(query: Query<&PlayerScore>) {
|
|
/// match query.get_single() {
|
|
/// Ok(PlayerScore(score)) => {
|
|
/// println!("Score: {}", score);
|
|
/// }
|
|
/// Err(QuerySingleError::NoEntities(_)) => {
|
|
/// println!("Error: There is no player!");
|
|
/// }
|
|
/// Err(QuerySingleError::MultipleEntities(_)) => {
|
|
/// println!("Error: There is more than one player!");
|
|
/// }
|
|
/// }
|
|
/// }
|
|
/// # bevy_ecs::system::assert_is_system(player_scoring_system);
|
|
/// ```
|
|
///
|
|
/// # See also
|
|
///
|
|
/// - [`get_single_mut`](Self::get_single_mut) to get the mutable query item.
|
|
/// - [`single`](Self::single) for the panicking version.
|
|
#[inline]
|
|
pub fn get_single(&self) -> Result<ROQueryItem<'_, D>, QuerySingleError> {
|
|
// SAFETY:
|
|
// the query ensures that the components it accesses are not mutably accessible somewhere else
|
|
// and the query is read only.
|
|
unsafe {
|
|
self.state.as_readonly().get_single_unchecked_manual(
|
|
self.world,
|
|
self.last_run,
|
|
self.this_run,
|
|
)
|
|
}
|
|
}
|
|
|
|
/// Returns a single query item when there is exactly one entity matching the query.
|
|
///
|
|
/// # Panics
|
|
///
|
|
/// This method panics if the number of query item is **not** exactly one.
|
|
///
|
|
/// # Example
|
|
///
|
|
/// ```
|
|
/// # use bevy_ecs::prelude::*;
|
|
/// #
|
|
/// # #[derive(Component)]
|
|
/// # struct Player;
|
|
/// # #[derive(Component)]
|
|
/// # struct Health(u32);
|
|
/// #
|
|
/// fn regenerate_player_health_system(mut query: Query<&mut Health, With<Player>>) {
|
|
/// let mut health = query.single_mut();
|
|
/// health.0 += 1;
|
|
/// }
|
|
/// # bevy_ecs::system::assert_is_system(regenerate_player_health_system);
|
|
/// ```
|
|
///
|
|
/// # See also
|
|
///
|
|
/// - [`get_single_mut`](Self::get_single_mut) for the non-panicking version.
|
|
/// - [`single`](Self::single) to get the read-only query item.
|
|
#[track_caller]
|
|
pub fn single_mut(&mut self) -> D::Item<'_> {
|
|
self.get_single_mut().unwrap()
|
|
}
|
|
|
|
/// Returns a single query item when there is exactly one entity matching the query.
|
|
///
|
|
/// If the number of query items is not exactly one, a [`QuerySingleError`] is returned instead.
|
|
///
|
|
/// # Example
|
|
///
|
|
/// ```
|
|
/// # use bevy_ecs::prelude::*;
|
|
/// #
|
|
/// # #[derive(Component)]
|
|
/// # struct Player;
|
|
/// # #[derive(Component)]
|
|
/// # struct Health(u32);
|
|
/// #
|
|
/// fn regenerate_player_health_system(mut query: Query<&mut Health, With<Player>>) {
|
|
/// let mut health = query.get_single_mut().expect("Error: Could not find a single player.");
|
|
/// health.0 += 1;
|
|
/// }
|
|
/// # bevy_ecs::system::assert_is_system(regenerate_player_health_system);
|
|
/// ```
|
|
///
|
|
/// # See also
|
|
///
|
|
/// - [`get_single`](Self::get_single) to get the read-only query item.
|
|
/// - [`single_mut`](Self::single_mut) for the panicking version.
|
|
#[inline]
|
|
pub fn get_single_mut(&mut self) -> Result<D::Item<'_>, QuerySingleError> {
|
|
// SAFETY:
|
|
// the query ensures mutable access to the components it accesses, and the query
|
|
// is uniquely borrowed
|
|
unsafe {
|
|
self.state
|
|
.get_single_unchecked_manual(self.world, self.last_run, self.this_run)
|
|
}
|
|
}
|
|
|
|
/// Returns `true` if there are no query items.
|
|
///
|
|
/// # Example
|
|
///
|
|
/// Here, the score is increased only if an entity with a `Player` component is present in the world:
|
|
///
|
|
/// ```
|
|
/// # use bevy_ecs::prelude::*;
|
|
/// #
|
|
/// # #[derive(Component)]
|
|
/// # struct Player;
|
|
/// # #[derive(Resource)]
|
|
/// # struct Score(u32);
|
|
/// fn update_score_system(query: Query<(), With<Player>>, mut score: ResMut<Score>) {
|
|
/// if !query.is_empty() {
|
|
/// score.0 += 1;
|
|
/// }
|
|
/// }
|
|
/// # bevy_ecs::system::assert_is_system(update_score_system);
|
|
/// ```
|
|
#[inline]
|
|
pub fn is_empty(&self) -> bool {
|
|
// SAFETY:
|
|
// - `self.world` has permission to read any data required by the WorldQuery.
|
|
// - `&self` ensures that no one currently has write access.
|
|
// - `self.world` matches `self.state`.
|
|
unsafe {
|
|
self.state
|
|
.is_empty_unsafe_world_cell(self.world, self.last_run, self.this_run)
|
|
}
|
|
}
|
|
|
|
/// Returns `true` if the given [`Entity`] matches the query.
|
|
///
|
|
/// # Example
|
|
///
|
|
/// ```
|
|
/// # use bevy_ecs::prelude::*;
|
|
/// #
|
|
/// # #[derive(Component)]
|
|
/// # struct InRange;
|
|
/// #
|
|
/// # #[derive(Resource)]
|
|
/// # struct Target {
|
|
/// # entity: Entity,
|
|
/// # }
|
|
/// #
|
|
/// fn targeting_system(in_range_query: Query<&InRange>, target: Res<Target>) {
|
|
/// if in_range_query.contains(target.entity) {
|
|
/// println!("Bam!")
|
|
/// }
|
|
/// }
|
|
/// # bevy_ecs::system::assert_is_system(targeting_system);
|
|
/// ```
|
|
#[inline]
|
|
pub fn contains(&self, entity: Entity) -> bool {
|
|
// SAFETY: NopFetch does not access any members while &self ensures no one has exclusive access
|
|
unsafe {
|
|
self.state
|
|
.as_nop()
|
|
.get_unchecked_manual(self.world, entity, self.last_run, self.this_run)
|
|
.is_ok()
|
|
}
|
|
}
|
|
|
|
/// Returns a [`QueryLens`] that can be used to get a query with a more general fetch.
|
|
///
|
|
/// For example, this can transform a `Query<(&A, &mut B)>` to a `Query<&B>`.
|
|
/// This can be useful for passing the query to another function. Note that since
|
|
/// filter terms are dropped, non-archetypal filters like [`Added`](crate::query::Added) and
|
|
/// [`Changed`](crate::query::Changed) will not be respected. To maintain or change filter
|
|
/// terms see [`Self::transmute_lens_filtered`]
|
|
///
|
|
/// ## Panics
|
|
///
|
|
/// This will panic if `NewD` is not a subset of the original fetch `Q`
|
|
///
|
|
/// ## Example
|
|
///
|
|
/// ```rust
|
|
/// # use bevy_ecs::prelude::*;
|
|
/// # use bevy_ecs::system::QueryLens;
|
|
/// #
|
|
/// # #[derive(Component)]
|
|
/// # struct A(usize);
|
|
/// #
|
|
/// # #[derive(Component)]
|
|
/// # struct B(usize);
|
|
/// #
|
|
/// # let mut world = World::new();
|
|
/// #
|
|
/// # world.spawn((A(10), B(5)));
|
|
/// #
|
|
/// fn reusable_function(lens: &mut QueryLens<&A>) {
|
|
/// assert_eq!(lens.query().single().0, 10);
|
|
/// }
|
|
///
|
|
/// // We can use the function in a system that takes the exact query.
|
|
/// fn system_1(mut query: Query<&A>) {
|
|
/// reusable_function(&mut query.as_query_lens());
|
|
/// }
|
|
///
|
|
/// // We can also use it with a query that does not match exactly
|
|
/// // by transmuting it.
|
|
/// fn system_2(mut query: Query<(&mut A, &B)>) {
|
|
/// let mut lens = query.transmute_lens::<&A>();
|
|
/// reusable_function(&mut lens);
|
|
/// }
|
|
///
|
|
/// # let mut schedule = Schedule::default();
|
|
/// # schedule.add_systems((system_1, system_2));
|
|
/// # schedule.run(&mut world);
|
|
/// ```
|
|
///
|
|
/// ## Allowed Transmutes
|
|
///
|
|
/// Besides removing parameters from the query, you can also
|
|
/// make limited changes to the types of paramters.
|
|
///
|
|
/// * Can always add/remove `Entity`
|
|
/// * `Ref<T>` <-> `&T`
|
|
/// * `&mut T` -> `&T`
|
|
/// * `&mut T` -> `Ref<T>`
|
|
/// * [`EntityMut`](crate::world::EntityMut) -> [`EntityRef`](crate::world::EntityRef)
|
|
///
|
|
pub fn transmute_lens<NewD: QueryData>(&mut self) -> QueryLens<'_, NewD> {
|
|
self.transmute_lens_filtered::<NewD, ()>()
|
|
}
|
|
|
|
/// Equivalent to [`Self::transmute_lens`] but also includes a [`QueryFilter`] type.
|
|
///
|
|
/// Note that the lens will iterate the same tables and archetypes as the original query. This means that
|
|
/// additional archetypal query terms like [`With`](crate::query::With) and [`Without`](crate::query::Without)
|
|
/// will not necessarily be respected and non-archetypal terms like [`Added`](crate::query::Added) and
|
|
/// [`Changed`](crate::query::Changed) will only be respected if they are in the type signature.
|
|
pub fn transmute_lens_filtered<NewD: QueryData, NewF: QueryFilter>(
|
|
&mut self,
|
|
) -> QueryLens<'_, NewD, NewF> {
|
|
// SAFETY: There are no other active borrows of data from world
|
|
let world = unsafe { self.world.world() };
|
|
let state = self.state.transmute_filtered::<NewD, NewF>(world);
|
|
QueryLens {
|
|
world: self.world,
|
|
state,
|
|
last_run: self.last_run,
|
|
this_run: self.this_run,
|
|
force_read_only_component_access: self.force_read_only_component_access,
|
|
}
|
|
}
|
|
|
|
/// Gets a [`QueryLens`] with the same accesses as the existing query
|
|
pub fn as_query_lens(&mut self) -> QueryLens<'_, D> {
|
|
self.transmute_lens()
|
|
}
|
|
}
|
|
|
|
impl<'w, 's, D: QueryData, F: QueryFilter> IntoIterator for &'w Query<'_, 's, D, F> {
|
|
type Item = ROQueryItem<'w, D>;
|
|
type IntoIter = QueryIter<'w, 's, D::ReadOnly, F>;
|
|
|
|
fn into_iter(self) -> Self::IntoIter {
|
|
self.iter()
|
|
}
|
|
}
|
|
|
|
impl<'w, 's, D: QueryData, F: QueryFilter> IntoIterator for &'w mut Query<'_, 's, D, F> {
|
|
type Item = D::Item<'w>;
|
|
type IntoIter = QueryIter<'w, 's, D, F>;
|
|
|
|
fn into_iter(self) -> Self::IntoIter {
|
|
self.iter_mut()
|
|
}
|
|
}
|
|
|
|
impl<'w, 's, D: ReadOnlyQueryData, F: QueryFilter> Query<'w, 's, D, F> {
|
|
/// Returns the query item for the given [`Entity`], with the actual "inner" world lifetime.
|
|
///
|
|
/// In case of a nonexisting entity or mismatched component, a [`QueryEntityError`] is
|
|
/// returned instead.
|
|
///
|
|
/// This can only return immutable data (mutable data will be cast to an immutable form).
|
|
/// See [`get_mut`](Self::get_mut) for queries that contain at least one mutable component.
|
|
///
|
|
/// # Example
|
|
///
|
|
/// Here, `get` is used to retrieve the exact query item of the entity specified by the
|
|
/// `SelectedCharacter` resource.
|
|
///
|
|
/// ```
|
|
/// # use bevy_ecs::prelude::*;
|
|
/// #
|
|
/// # #[derive(Resource)]
|
|
/// # struct SelectedCharacter { entity: Entity }
|
|
/// # #[derive(Component)]
|
|
/// # struct Character { name: String }
|
|
/// #
|
|
/// fn print_selected_character_name_system(
|
|
/// query: Query<&Character>,
|
|
/// selection: Res<SelectedCharacter>
|
|
/// )
|
|
/// {
|
|
/// if let Ok(selected_character) = query.get(selection.entity) {
|
|
/// println!("{}", selected_character.name);
|
|
/// }
|
|
/// }
|
|
/// # bevy_ecs::system::assert_is_system(print_selected_character_name_system);
|
|
/// ```
|
|
#[inline]
|
|
pub fn get_inner(&self, entity: Entity) -> Result<ROQueryItem<'w, D>, QueryEntityError> {
|
|
// SAFETY: system runs without conflicts with other systems.
|
|
// same-system queries have runtime borrow checks when they conflict
|
|
unsafe {
|
|
self.state.as_readonly().get_unchecked_manual(
|
|
self.world,
|
|
entity,
|
|
self.last_run,
|
|
self.this_run,
|
|
)
|
|
}
|
|
}
|
|
|
|
/// Returns an [`Iterator`] over the query items, with the actual "inner" world lifetime.
|
|
///
|
|
/// This can only return immutable data (mutable data will be cast to an immutable form).
|
|
/// See [`Self::iter_mut`] for queries that contain at least one mutable component.
|
|
///
|
|
/// # Example
|
|
///
|
|
/// Here, the `report_names_system` iterates over the `Player` component of every entity
|
|
/// that contains it:
|
|
///
|
|
/// ```
|
|
/// # use bevy_ecs::prelude::*;
|
|
/// #
|
|
/// # #[derive(Component)]
|
|
/// # struct Player { name: String }
|
|
/// #
|
|
/// fn report_names_system(query: Query<&Player>) {
|
|
/// for player in &query {
|
|
/// println!("Say hello to {}!", player.name);
|
|
/// }
|
|
/// }
|
|
/// # bevy_ecs::system::assert_is_system(report_names_system);
|
|
/// ```
|
|
#[inline]
|
|
pub fn iter_inner(&self) -> QueryIter<'w, 's, D::ReadOnly, F> {
|
|
// SAFETY: system runs without conflicts with other systems.
|
|
// same-system queries have runtime borrow checks when they conflict
|
|
unsafe {
|
|
self.state
|
|
.as_readonly()
|
|
.iter_unchecked_manual(self.world, self.last_run, self.this_run)
|
|
}
|
|
}
|
|
}
|
|
|
|
/// Type returned from [`Query::transmute_lens`] containing the new [`QueryState`].
|
|
///
|
|
/// Call [`query`](QueryLens::query) or [`into`](Into::into) to construct the resulting [`Query`]
|
|
pub struct QueryLens<'w, Q: QueryData, F: QueryFilter = ()> {
|
|
world: UnsafeWorldCell<'w>,
|
|
state: QueryState<Q, F>,
|
|
last_run: Tick,
|
|
this_run: Tick,
|
|
force_read_only_component_access: bool,
|
|
}
|
|
|
|
impl<'w, Q: QueryData, F: QueryFilter> QueryLens<'w, Q, F> {
|
|
/// Create a [`Query`] from the underlying [`QueryState`].
|
|
pub fn query(&mut self) -> Query<'w, '_, Q, F> {
|
|
Query {
|
|
world: self.world,
|
|
state: &self.state,
|
|
last_run: self.last_run,
|
|
this_run: self.this_run,
|
|
force_read_only_component_access: self.force_read_only_component_access,
|
|
}
|
|
}
|
|
}
|
|
|
|
impl<'w, 's, Q: QueryData, F: QueryFilter> From<&'s mut QueryLens<'w, Q, F>>
|
|
for Query<'w, 's, Q, F>
|
|
{
|
|
fn from(value: &'s mut QueryLens<'w, Q, F>) -> Query<'w, 's, Q, F> {
|
|
value.query()
|
|
}
|
|
}
|
|
|
|
impl<'w, 'q, Q: QueryData, F: QueryFilter> From<&'q mut Query<'w, '_, Q, F>>
|
|
for QueryLens<'q, Q, F>
|
|
{
|
|
fn from(value: &'q mut Query<'w, '_, Q, F>) -> QueryLens<'q, Q, F> {
|
|
value.transmute_lens_filtered()
|
|
}
|
|
}
|