2990 lines
110 KiB
Rust
2990 lines
110 KiB
Rust
//! Types for declaring and storing [`Component`]s.
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use crate::{
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archetype::ArchetypeFlags,
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bundle::BundleInfo,
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change_detection::{MaybeLocation, MAX_CHANGE_AGE},
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entity::{ComponentCloneCtx, Entity, EntityMapper, SourceComponent},
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lifecycle::{ComponentHook, ComponentHooks},
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query::DebugCheckedUnwrap,
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resource::Resource,
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storage::{SparseSetIndex, SparseSets, Table, TableRow},
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system::{Local, SystemParam},
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world::{FromWorld, World},
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};
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use alloc::boxed::Box;
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use alloc::{borrow::Cow, format, vec::Vec};
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pub use bevy_ecs_macros::Component;
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use bevy_ecs_macros::Event;
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use bevy_platform::sync::Arc;
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use bevy_platform::{
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collections::{HashMap, HashSet},
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sync::PoisonError,
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};
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use bevy_ptr::{OwningPtr, UnsafeCellDeref};
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#[cfg(feature = "bevy_reflect")]
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use bevy_reflect::Reflect;
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use bevy_utils::{prelude::DebugName, TypeIdMap};
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use core::{
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alloc::Layout,
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any::{Any, TypeId},
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cell::UnsafeCell,
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fmt::Debug,
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marker::PhantomData,
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mem::needs_drop,
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ops::{Deref, DerefMut},
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};
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use smallvec::SmallVec;
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use thiserror::Error;
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/// A data type that can be used to store data for an [entity].
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///
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/// `Component` is a [derivable trait]: this means that a data type can implement it by applying a `#[derive(Component)]` attribute to it.
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/// However, components must always satisfy the `Send + Sync + 'static` trait bounds.
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///
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/// [entity]: crate::entity
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/// [derivable trait]: https://doc.rust-lang.org/book/appendix-03-derivable-traits.html
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///
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/// # Examples
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///
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/// Components can take many forms: they are usually structs, but can also be of every other kind of data type, like enums or zero sized types.
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/// The following examples show how components are laid out in code.
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///
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/// ```
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/// # use bevy_ecs::component::Component;
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/// # struct Color;
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/// #
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/// // A component can contain data...
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/// #[derive(Component)]
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/// struct LicensePlate(String);
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///
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/// // ... but it can also be a zero-sized marker.
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/// #[derive(Component)]
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/// struct Car;
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///
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/// // Components can also be structs with named fields...
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/// #[derive(Component)]
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/// struct VehiclePerformance {
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/// acceleration: f32,
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/// top_speed: f32,
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/// handling: f32,
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/// }
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///
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/// // ... or enums.
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/// #[derive(Component)]
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/// enum WheelCount {
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/// Two,
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/// Three,
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/// Four,
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/// }
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/// ```
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///
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/// # Component and data access
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///
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/// Components can be marked as immutable by adding the `#[component(immutable)]`
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/// attribute when using the derive macro.
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/// See the documentation for [`ComponentMutability`] for more details around this
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/// feature.
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///
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/// See the [`entity`] module level documentation to learn how to add or remove components from an entity.
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///
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/// See the documentation for [`Query`] to learn how to access component data from a system.
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///
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/// [`entity`]: crate::entity#usage
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/// [`Query`]: crate::system::Query
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/// [`ComponentMutability`]: crate::component::ComponentMutability
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///
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/// # Choosing a storage type
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///
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/// Components can be stored in the world using different strategies with their own performance implications.
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/// By default, components are added to the [`Table`] storage, which is optimized for query iteration.
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///
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/// Alternatively, components can be added to the [`SparseSet`] storage, which is optimized for component insertion and removal.
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/// This is achieved by adding an additional `#[component(storage = "SparseSet")]` attribute to the derive one:
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///
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/// ```
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/// # use bevy_ecs::component::Component;
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/// #
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/// #[derive(Component)]
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/// #[component(storage = "SparseSet")]
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/// struct ComponentA;
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/// ```
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///
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/// [`Table`]: crate::storage::Table
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/// [`SparseSet`]: crate::storage::SparseSet
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///
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/// # Required Components
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///
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/// Components can specify Required Components. If some [`Component`] `A` requires [`Component`] `B`, then when `A` is inserted,
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/// `B` will _also_ be initialized and inserted (if it was not manually specified).
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///
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/// The [`Default`] constructor will be used to initialize the component, by default:
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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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/// #[require(B)]
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/// struct A;
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///
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/// #[derive(Component, Default, PartialEq, Eq, Debug)]
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/// struct B(usize);
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///
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/// # let mut world = World::default();
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/// // This will implicitly also insert B with the Default constructor
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/// let id = world.spawn(A).id();
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/// assert_eq!(&B(0), world.entity(id).get::<B>().unwrap());
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///
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/// // This will _not_ implicitly insert B, because it was already provided
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/// world.spawn((A, B(11)));
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/// ```
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///
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/// Components can have more than one required 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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/// #[require(B, C)]
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/// struct A;
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///
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/// #[derive(Component, Default, PartialEq, Eq, Debug)]
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/// #[require(C)]
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/// struct B(usize);
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///
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/// #[derive(Component, Default, PartialEq, Eq, Debug)]
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/// struct C(u32);
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///
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/// # let mut world = World::default();
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/// // This will implicitly also insert B and C with their Default constructors
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/// let id = world.spawn(A).id();
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/// assert_eq!(&B(0), world.entity(id).get::<B>().unwrap());
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/// assert_eq!(&C(0), world.entity(id).get::<C>().unwrap());
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/// ```
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///
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/// You can define inline component values that take the following forms:
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/// ```
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/// # use bevy_ecs::prelude::*;
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/// #[derive(Component)]
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/// #[require(
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/// B(1), // tuple structs
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/// C { // named-field structs
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/// x: 1,
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/// ..Default::default()
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/// },
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/// D::One, // enum variants
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/// E::ONE, // associated consts
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/// F::new(1) // constructors
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/// )]
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/// struct A;
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///
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/// #[derive(Component, PartialEq, Eq, Debug)]
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/// struct B(u8);
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///
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/// #[derive(Component, PartialEq, Eq, Debug, Default)]
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/// struct C {
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/// x: u8,
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/// y: u8,
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/// }
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///
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/// #[derive(Component, PartialEq, Eq, Debug)]
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/// enum D {
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/// Zero,
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/// One,
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/// }
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///
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/// #[derive(Component, PartialEq, Eq, Debug)]
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/// struct E(u8);
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///
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/// impl E {
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/// pub const ONE: Self = Self(1);
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/// }
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///
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/// #[derive(Component, PartialEq, Eq, Debug)]
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/// struct F(u8);
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///
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/// impl F {
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/// fn new(value: u8) -> Self {
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/// Self(value)
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/// }
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/// }
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///
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/// # let mut world = World::default();
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/// let id = world.spawn(A).id();
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/// assert_eq!(&B(1), world.entity(id).get::<B>().unwrap());
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/// assert_eq!(&C { x: 1, y: 0 }, world.entity(id).get::<C>().unwrap());
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/// assert_eq!(&D::One, world.entity(id).get::<D>().unwrap());
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/// assert_eq!(&E(1), world.entity(id).get::<E>().unwrap());
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/// assert_eq!(&F(1), world.entity(id).get::<F>().unwrap());
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/// ````
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///
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///
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/// You can also define arbitrary expressions by using `=`
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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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/// #[require(C = init_c())]
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/// struct A;
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///
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/// #[derive(Component, PartialEq, Eq, Debug)]
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/// #[require(C = C(20))]
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/// struct B;
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///
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/// #[derive(Component, PartialEq, Eq, Debug)]
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/// struct C(usize);
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///
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/// fn init_c() -> C {
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/// C(10)
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/// }
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///
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/// # let mut world = World::default();
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/// // This will implicitly also insert C with the init_c() constructor
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/// let id = world.spawn(A).id();
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/// assert_eq!(&C(10), world.entity(id).get::<C>().unwrap());
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///
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/// // This will implicitly also insert C with the `|| C(20)` constructor closure
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/// let id = world.spawn(B).id();
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/// assert_eq!(&C(20), world.entity(id).get::<C>().unwrap());
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/// ```
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///
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/// Required components are _recursive_. This means, if a Required Component has required components,
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/// those components will _also_ be inserted if they are missing:
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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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/// #[require(B)]
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/// struct A;
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///
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/// #[derive(Component, Default, PartialEq, Eq, Debug)]
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/// #[require(C)]
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/// struct B(usize);
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///
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/// #[derive(Component, Default, PartialEq, Eq, Debug)]
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/// struct C(u32);
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///
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/// # let mut world = World::default();
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/// // This will implicitly also insert B and C with their Default constructors
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/// let id = world.spawn(A).id();
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/// assert_eq!(&B(0), world.entity(id).get::<B>().unwrap());
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/// assert_eq!(&C(0), world.entity(id).get::<C>().unwrap());
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/// ```
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///
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/// Note that cycles in the "component require tree" will result in stack overflows when attempting to
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/// insert a component.
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///
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/// This "multiple inheritance" pattern does mean that it is possible to have duplicate requires for a given type
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/// at different levels of the inheritance tree:
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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 X(usize);
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///
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/// #[derive(Component, Default)]
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/// #[require(X(1))]
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/// struct Y;
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///
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/// #[derive(Component)]
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/// #[require(
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/// Y,
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/// X(2),
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/// )]
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/// struct Z;
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///
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/// # let mut world = World::default();
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/// // In this case, the x2 constructor is used for X
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/// let id = world.spawn(Z).id();
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/// assert_eq!(2, world.entity(id).get::<X>().unwrap().0);
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/// ```
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///
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/// In general, this shouldn't happen often, but when it does the algorithm for choosing the constructor from the tree is simple and predictable:
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/// 1. A constructor from a direct `#[require()]`, if one exists, is selected with priority.
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/// 2. Otherwise, perform a Depth First Search on the tree of requirements and select the first one found.
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///
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/// From a user perspective, just think about this as the following:
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/// 1. Specifying a required component constructor for Foo directly on a spawned component Bar will result in that constructor being used (and overriding existing constructors lower in the inheritance tree). This is the classic "inheritance override" behavior people expect.
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/// 2. For cases where "multiple inheritance" results in constructor clashes, Components should be listed in "importance order". List a component earlier in the requirement list to initialize its inheritance tree earlier.
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///
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/// ## Registering required components at runtime
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///
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/// In most cases, required components should be registered using the `require` attribute as shown above.
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/// However, in some cases, it may be useful to register required components at runtime.
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///
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/// This can be done through [`World::register_required_components`] or [`World::register_required_components_with`]
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/// for the [`Default`] and custom constructors respectively:
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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 A;
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///
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/// #[derive(Component, Default, PartialEq, Eq, Debug)]
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/// struct B(usize);
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///
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/// #[derive(Component, PartialEq, Eq, Debug)]
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/// struct C(u32);
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///
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/// # let mut world = World::default();
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/// // Register B as required by A and C as required by B.
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/// world.register_required_components::<A, B>();
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/// world.register_required_components_with::<B, C>(|| C(2));
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///
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/// // This will implicitly also insert B with its Default constructor
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/// // and C with the custom constructor defined by B.
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/// let id = world.spawn(A).id();
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/// assert_eq!(&B(0), world.entity(id).get::<B>().unwrap());
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/// assert_eq!(&C(2), world.entity(id).get::<C>().unwrap());
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/// ```
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///
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/// Similar rules as before apply to duplicate requires fer a given type at different levels
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/// of the inheritance tree. `A` requiring `C` directly would take precedence over indirectly
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/// requiring it through `A` requiring `B` and `B` requiring `C`.
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///
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/// Unlike with the `require` attribute, directly requiring the same component multiple times
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/// for the same component will result in a panic. This is done to prevent conflicting constructors
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/// and confusing ordering dependencies.
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///
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/// Note that requirements must currently be registered before the requiring component is inserted
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/// into the world for the first time. Registering requirements after this will lead to a panic.
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///
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/// # Relationships between Entities
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///
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/// Sometimes it is useful to define relationships between entities. A common example is the
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/// parent / child relationship. Since Components are how data is stored for Entities, one might
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/// naturally think to create a Component which has a field of type [`Entity`].
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///
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/// To facilitate this pattern, Bevy provides the [`Relationship`](`crate::relationship::Relationship`)
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/// trait. You can derive the [`Relationship`](`crate::relationship::Relationship`) and
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/// [`RelationshipTarget`](`crate::relationship::RelationshipTarget`) traits in addition to the
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/// Component trait in order to implement data driven relationships between entities, see the trait
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/// docs for more details.
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///
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/// In addition, Bevy provides canonical implementations of the parent / child relationship via the
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/// [`ChildOf`](crate::hierarchy::ChildOf) [`Relationship`](crate::relationship::Relationship) and
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/// the [`Children`](crate::hierarchy::Children)
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/// [`RelationshipTarget`](crate::relationship::RelationshipTarget).
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///
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/// # Adding component's hooks
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///
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/// See [`ComponentHooks`] for a detailed explanation of component's hooks.
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///
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/// Alternatively to the example shown in [`ComponentHooks`]' documentation, hooks can be configured using following attributes:
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/// - `#[component(on_add = on_add_function)]`
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/// - `#[component(on_insert = on_insert_function)]`
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/// - `#[component(on_replace = on_replace_function)]`
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/// - `#[component(on_remove = on_remove_function)]`
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///
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/// ```
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/// # use bevy_ecs::component::Component;
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/// # use bevy_ecs::lifecycle::HookContext;
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/// # use bevy_ecs::world::DeferredWorld;
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/// # use bevy_ecs::entity::Entity;
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/// # use bevy_ecs::component::ComponentId;
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/// # use core::panic::Location;
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/// #
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/// #[derive(Component)]
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/// #[component(on_add = my_on_add_hook)]
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/// #[component(on_insert = my_on_insert_hook)]
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/// // Another possible way of configuring hooks:
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/// // #[component(on_add = my_on_add_hook, on_insert = my_on_insert_hook)]
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/// //
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/// // We don't have a replace or remove hook, so we can leave them out:
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/// // #[component(on_replace = my_on_replace_hook, on_remove = my_on_remove_hook)]
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/// struct ComponentA;
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///
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/// fn my_on_add_hook(world: DeferredWorld, context: HookContext) {
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/// // ...
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/// }
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///
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/// // You can also destructure items directly in the signature
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/// fn my_on_insert_hook(world: DeferredWorld, HookContext { caller, .. }: HookContext) {
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/// // ...
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/// }
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/// ```
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///
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/// This also supports function calls that yield closures
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///
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/// ```
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/// # use bevy_ecs::component::Component;
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/// # use bevy_ecs::lifecycle::HookContext;
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/// # use bevy_ecs::world::DeferredWorld;
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/// #
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/// #[derive(Component)]
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/// #[component(on_add = my_msg_hook("hello"))]
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/// #[component(on_despawn = my_msg_hook("yoink"))]
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/// struct ComponentA;
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///
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/// // a hook closure generating function
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/// fn my_msg_hook(message: &'static str) -> impl Fn(DeferredWorld, HookContext) {
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/// move |_world, _ctx| {
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/// println!("{message}");
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/// }
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/// }
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///
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/// ```
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/// # Setting the clone behavior
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///
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/// You can specify how the [`Component`] is cloned when deriving it.
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///
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/// Your options are the functions and variants of [`ComponentCloneBehavior`]
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/// See [Handlers section of `EntityClonerBuilder`](crate::entity::EntityClonerBuilder#handlers) to understand how this affects handler priority.
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/// ```
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/// # use bevy_ecs::prelude::*;
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///
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/// #[derive(Component)]
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/// #[component(clone_behavior = Ignore)]
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/// struct MyComponent;
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///
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/// ```
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///
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/// # Implementing the trait for foreign types
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///
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/// As a consequence of the [orphan rule], it is not possible to separate into two different crates the implementation of `Component` from the definition of a type.
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/// This means that it is not possible to directly have a type defined in a third party library as a component.
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/// This important limitation can be easily worked around using the [newtype pattern]:
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/// this makes it possible to locally define and implement `Component` for a tuple struct that wraps the foreign type.
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/// The following example gives a demonstration of this pattern.
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///
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/// ```
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/// // `Component` is defined in the `bevy_ecs` crate.
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/// use bevy_ecs::component::Component;
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///
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/// // `Duration` is defined in the `std` crate.
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/// use std::time::Duration;
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///
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/// // It is not possible to implement `Component` for `Duration` from this position, as they are
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/// // both foreign items, defined in an external crate. However, nothing prevents to define a new
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/// // `Cooldown` type that wraps `Duration`. As `Cooldown` is defined in a local crate, it is
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/// // possible to implement `Component` for it.
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/// #[derive(Component)]
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/// struct Cooldown(Duration);
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/// ```
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///
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/// [orphan rule]: https://doc.rust-lang.org/book/ch10-02-traits.html#implementing-a-trait-on-a-type
|
|
/// [newtype pattern]: https://doc.rust-lang.org/book/ch19-03-advanced-traits.html#using-the-newtype-pattern-to-implement-external-traits-on-external-types
|
|
///
|
|
/// # `!Sync` Components
|
|
/// A `!Sync` type cannot implement `Component`. However, it is possible to wrap a `Send` but not `Sync`
|
|
/// type in [`SyncCell`] or the currently unstable [`Exclusive`] to make it `Sync`. This forces only
|
|
/// having mutable access (`&mut T` only, never `&T`), but makes it safe to reference across multiple
|
|
/// threads.
|
|
///
|
|
/// This will fail to compile since `RefCell` is `!Sync`.
|
|
/// ```compile_fail
|
|
/// # use std::cell::RefCell;
|
|
/// # use bevy_ecs::component::Component;
|
|
/// #[derive(Component)]
|
|
/// struct NotSync {
|
|
/// counter: RefCell<usize>,
|
|
/// }
|
|
/// ```
|
|
///
|
|
/// This will compile since the `RefCell` is wrapped with `SyncCell`.
|
|
/// ```
|
|
/// # use std::cell::RefCell;
|
|
/// # use bevy_ecs::component::Component;
|
|
/// use bevy_platform::cell::SyncCell;
|
|
///
|
|
/// // This will compile.
|
|
/// #[derive(Component)]
|
|
/// struct ActuallySync {
|
|
/// counter: SyncCell<RefCell<usize>>,
|
|
/// }
|
|
/// ```
|
|
///
|
|
/// [`SyncCell`]: bevy_platform::cell::SyncCell
|
|
/// [`Exclusive`]: https://doc.rust-lang.org/nightly/std/sync/struct.Exclusive.html
|
|
#[diagnostic::on_unimplemented(
|
|
message = "`{Self}` is not a `Component`",
|
|
label = "invalid `Component`",
|
|
note = "consider annotating `{Self}` with `#[derive(Component)]`"
|
|
)]
|
|
pub trait Component: Send + Sync + 'static {
|
|
/// A constant indicating the storage type used for this component.
|
|
const STORAGE_TYPE: StorageType;
|
|
|
|
/// A marker type to assist Bevy with determining if this component is
|
|
/// mutable, or immutable. Mutable components will have [`Component<Mutability = Mutable>`],
|
|
/// while immutable components will instead have [`Component<Mutability = Immutable>`].
|
|
///
|
|
/// * For a component to be mutable, this type must be [`Mutable`].
|
|
/// * For a component to be immutable, this type must be [`Immutable`].
|
|
type Mutability: ComponentMutability;
|
|
|
|
/// Gets the `on_add` [`ComponentHook`] for this [`Component`] if one is defined.
|
|
fn on_add() -> Option<ComponentHook> {
|
|
None
|
|
}
|
|
|
|
/// Gets the `on_insert` [`ComponentHook`] for this [`Component`] if one is defined.
|
|
fn on_insert() -> Option<ComponentHook> {
|
|
None
|
|
}
|
|
|
|
/// Gets the `on_replace` [`ComponentHook`] for this [`Component`] if one is defined.
|
|
fn on_replace() -> Option<ComponentHook> {
|
|
None
|
|
}
|
|
|
|
/// Gets the `on_remove` [`ComponentHook`] for this [`Component`] if one is defined.
|
|
fn on_remove() -> Option<ComponentHook> {
|
|
None
|
|
}
|
|
|
|
/// Gets the `on_despawn` [`ComponentHook`] for this [`Component`] if one is defined.
|
|
fn on_despawn() -> Option<ComponentHook> {
|
|
None
|
|
}
|
|
|
|
/// Registers required components.
|
|
fn register_required_components(
|
|
_component_id: ComponentId,
|
|
_components: &mut ComponentsRegistrator,
|
|
_required_components: &mut RequiredComponents,
|
|
_inheritance_depth: u16,
|
|
_recursion_check_stack: &mut Vec<ComponentId>,
|
|
) {
|
|
}
|
|
|
|
/// Called when registering this component, allowing to override clone function (or disable cloning altogether) for this component.
|
|
///
|
|
/// See [Handlers section of `EntityClonerBuilder`](crate::entity::EntityClonerBuilder#handlers) to understand how this affects handler priority.
|
|
#[inline]
|
|
fn clone_behavior() -> ComponentCloneBehavior {
|
|
ComponentCloneBehavior::Default
|
|
}
|
|
|
|
/// Maps the entities on this component using the given [`EntityMapper`]. This is used to remap entities in contexts like scenes and entity cloning.
|
|
/// When deriving [`Component`], this is populated by annotating fields containing entities with `#[entities]`
|
|
///
|
|
/// ```
|
|
/// # use bevy_ecs::{component::Component, entity::Entity};
|
|
/// #[derive(Component)]
|
|
/// struct Inventory {
|
|
/// #[entities]
|
|
/// items: Vec<Entity>
|
|
/// }
|
|
/// ```
|
|
///
|
|
/// Fields with `#[entities]` must implement [`MapEntities`](crate::entity::MapEntities).
|
|
///
|
|
/// Bevy provides various implementations of [`MapEntities`](crate::entity::MapEntities), so that arbitrary combinations like these are supported with `#[entities]`:
|
|
///
|
|
/// ```rust
|
|
/// # use bevy_ecs::{component::Component, entity::Entity};
|
|
/// #[derive(Component)]
|
|
/// struct Inventory {
|
|
/// #[entities]
|
|
/// items: Vec<Option<Entity>>
|
|
/// }
|
|
/// ```
|
|
#[inline]
|
|
fn map_entities<E: EntityMapper>(_this: &mut Self, _mapper: &mut E) {}
|
|
}
|
|
|
|
mod private {
|
|
pub trait Seal {}
|
|
}
|
|
|
|
/// The mutability option for a [`Component`]. This can either be:
|
|
/// * [`Mutable`]
|
|
/// * [`Immutable`]
|
|
///
|
|
/// This is controlled through either [`Component::Mutability`] or `#[component(immutable)]`
|
|
/// when using the derive macro.
|
|
///
|
|
/// Immutable components are guaranteed to never have an exclusive reference,
|
|
/// `&mut ...`, created while inserted onto an entity.
|
|
/// In all other ways, they are identical to mutable components.
|
|
/// This restriction allows hooks to observe all changes made to an immutable
|
|
/// component, effectively turning the `Insert` and `Replace` hooks into a
|
|
/// `OnMutate` hook.
|
|
/// This is not practical for mutable components, as the runtime cost of invoking
|
|
/// a hook for every exclusive reference created would be far too high.
|
|
///
|
|
/// # Examples
|
|
///
|
|
/// ```rust
|
|
/// # use bevy_ecs::component::Component;
|
|
/// #
|
|
/// #[derive(Component)]
|
|
/// #[component(immutable)]
|
|
/// struct ImmutableFoo;
|
|
/// ```
|
|
pub trait ComponentMutability: private::Seal + 'static {
|
|
/// Boolean to indicate if this mutability setting implies a mutable or immutable
|
|
/// component.
|
|
const MUTABLE: bool;
|
|
}
|
|
|
|
/// Parameter indicating a [`Component`] is immutable.
|
|
///
|
|
/// See [`ComponentMutability`] for details.
|
|
pub struct Immutable;
|
|
|
|
impl private::Seal for Immutable {}
|
|
impl ComponentMutability for Immutable {
|
|
const MUTABLE: bool = false;
|
|
}
|
|
|
|
/// Parameter indicating a [`Component`] is mutable.
|
|
///
|
|
/// See [`ComponentMutability`] for details.
|
|
pub struct Mutable;
|
|
|
|
impl private::Seal for Mutable {}
|
|
impl ComponentMutability for Mutable {
|
|
const MUTABLE: bool = true;
|
|
}
|
|
|
|
/// The storage used for a specific component type.
|
|
///
|
|
/// # Examples
|
|
/// The [`StorageType`] for a component is configured via the derive attribute
|
|
///
|
|
/// ```
|
|
/// # use bevy_ecs::{prelude::*, component::*};
|
|
/// #[derive(Component)]
|
|
/// #[component(storage = "SparseSet")]
|
|
/// struct A;
|
|
/// ```
|
|
#[derive(Debug, Copy, Clone, Default, Eq, PartialEq)]
|
|
pub enum StorageType {
|
|
/// Provides fast and cache-friendly iteration, but slower addition and removal of components.
|
|
/// This is the default storage type.
|
|
#[default]
|
|
Table,
|
|
/// Provides fast addition and removal of components, but slower iteration.
|
|
SparseSet,
|
|
}
|
|
|
|
/// Stores metadata for a type of component or resource stored in a specific [`World`].
|
|
#[derive(Debug, Clone)]
|
|
pub struct ComponentInfo {
|
|
id: ComponentId,
|
|
descriptor: ComponentDescriptor,
|
|
hooks: ComponentHooks,
|
|
required_components: RequiredComponents,
|
|
required_by: HashSet<ComponentId>,
|
|
}
|
|
|
|
impl ComponentInfo {
|
|
/// Returns a value uniquely identifying the current component.
|
|
#[inline]
|
|
pub fn id(&self) -> ComponentId {
|
|
self.id
|
|
}
|
|
|
|
/// Returns the name of the current component.
|
|
#[inline]
|
|
pub fn name(&self) -> DebugName {
|
|
self.descriptor.name.clone()
|
|
}
|
|
|
|
/// Returns `true` if the current component is mutable.
|
|
#[inline]
|
|
pub fn mutable(&self) -> bool {
|
|
self.descriptor.mutable
|
|
}
|
|
|
|
/// Returns [`ComponentCloneBehavior`] of the current component.
|
|
#[inline]
|
|
pub fn clone_behavior(&self) -> &ComponentCloneBehavior {
|
|
&self.descriptor.clone_behavior
|
|
}
|
|
|
|
/// Returns the [`TypeId`] of the underlying component type.
|
|
/// Returns `None` if the component does not correspond to a Rust type.
|
|
#[inline]
|
|
pub fn type_id(&self) -> Option<TypeId> {
|
|
self.descriptor.type_id
|
|
}
|
|
|
|
/// Returns the layout used to store values of this component in memory.
|
|
#[inline]
|
|
pub fn layout(&self) -> Layout {
|
|
self.descriptor.layout
|
|
}
|
|
|
|
#[inline]
|
|
/// Get the function which should be called to clean up values of
|
|
/// the underlying component type. This maps to the
|
|
/// [`Drop`] implementation for 'normal' Rust components
|
|
///
|
|
/// Returns `None` if values of the underlying component type don't
|
|
/// need to be dropped, e.g. as reported by [`needs_drop`].
|
|
pub fn drop(&self) -> Option<unsafe fn(OwningPtr<'_>)> {
|
|
self.descriptor.drop
|
|
}
|
|
|
|
/// Returns a value indicating the storage strategy for the current component.
|
|
#[inline]
|
|
pub fn storage_type(&self) -> StorageType {
|
|
self.descriptor.storage_type
|
|
}
|
|
|
|
/// Returns `true` if the underlying component type can be freely shared between threads.
|
|
/// If this returns `false`, then extra care must be taken to ensure that components
|
|
/// are not accessed from the wrong thread.
|
|
#[inline]
|
|
pub fn is_send_and_sync(&self) -> bool {
|
|
self.descriptor.is_send_and_sync
|
|
}
|
|
|
|
/// Create a new [`ComponentInfo`].
|
|
pub(crate) fn new(id: ComponentId, descriptor: ComponentDescriptor) -> Self {
|
|
ComponentInfo {
|
|
id,
|
|
descriptor,
|
|
hooks: Default::default(),
|
|
required_components: Default::default(),
|
|
required_by: Default::default(),
|
|
}
|
|
}
|
|
|
|
/// Update the given flags to include any [`ComponentHook`] registered to self
|
|
#[inline]
|
|
pub(crate) fn update_archetype_flags(&self, flags: &mut ArchetypeFlags) {
|
|
if self.hooks().on_add.is_some() {
|
|
flags.insert(ArchetypeFlags::ON_ADD_HOOK);
|
|
}
|
|
if self.hooks().on_insert.is_some() {
|
|
flags.insert(ArchetypeFlags::ON_INSERT_HOOK);
|
|
}
|
|
if self.hooks().on_replace.is_some() {
|
|
flags.insert(ArchetypeFlags::ON_REPLACE_HOOK);
|
|
}
|
|
if self.hooks().on_remove.is_some() {
|
|
flags.insert(ArchetypeFlags::ON_REMOVE_HOOK);
|
|
}
|
|
if self.hooks().on_despawn.is_some() {
|
|
flags.insert(ArchetypeFlags::ON_DESPAWN_HOOK);
|
|
}
|
|
}
|
|
|
|
/// Provides a reference to the collection of hooks associated with this [`Component`]
|
|
pub fn hooks(&self) -> &ComponentHooks {
|
|
&self.hooks
|
|
}
|
|
|
|
/// Retrieves the [`RequiredComponents`] collection, which contains all required components (and their constructors)
|
|
/// needed by this component. This includes _recursive_ required components.
|
|
pub fn required_components(&self) -> &RequiredComponents {
|
|
&self.required_components
|
|
}
|
|
}
|
|
|
|
/// A value which uniquely identifies the type of a [`Component`] or [`Resource`] within a
|
|
/// [`World`].
|
|
///
|
|
/// Each time a new `Component` type is registered within a `World` using
|
|
/// e.g. [`World::register_component`] or [`World::register_component_with_descriptor`]
|
|
/// or a Resource with e.g. [`World::init_resource`],
|
|
/// a corresponding `ComponentId` is created to track it.
|
|
///
|
|
/// While the distinction between `ComponentId` and [`TypeId`] may seem superficial, breaking them
|
|
/// into two separate but related concepts allows components to exist outside of Rust's type system.
|
|
/// Each Rust type registered as a `Component` will have a corresponding `ComponentId`, but additional
|
|
/// `ComponentId`s may exist in a `World` to track components which cannot be
|
|
/// represented as Rust types for scripting or other advanced use-cases.
|
|
///
|
|
/// A `ComponentId` is tightly coupled to its parent `World`. Attempting to use a `ComponentId` from
|
|
/// one `World` to access the metadata of a `Component` in a different `World` is undefined behavior
|
|
/// and must not be attempted.
|
|
///
|
|
/// Given a type `T` which implements [`Component`], the `ComponentId` for `T` can be retrieved
|
|
/// from a `World` using [`World::component_id()`] or via [`Components::component_id()`]. Access
|
|
/// to the `ComponentId` for a [`Resource`] is available via [`Components::resource_id()`].
|
|
#[derive(Debug, Copy, Clone, Hash, Ord, PartialOrd, Eq, PartialEq)]
|
|
#[cfg_attr(
|
|
feature = "bevy_reflect",
|
|
derive(Reflect),
|
|
reflect(Debug, Hash, PartialEq, Clone)
|
|
)]
|
|
pub struct ComponentId(usize);
|
|
|
|
impl ComponentId {
|
|
/// Creates a new [`ComponentId`].
|
|
///
|
|
/// The `index` is a unique value associated with each type of component in a given world.
|
|
/// Usually, this value is taken from a counter incremented for each type of component registered with the world.
|
|
#[inline]
|
|
pub const fn new(index: usize) -> ComponentId {
|
|
ComponentId(index)
|
|
}
|
|
|
|
/// Returns the index of the current component.
|
|
#[inline]
|
|
pub fn index(self) -> usize {
|
|
self.0
|
|
}
|
|
}
|
|
|
|
impl SparseSetIndex for ComponentId {
|
|
#[inline]
|
|
fn sparse_set_index(&self) -> usize {
|
|
self.index()
|
|
}
|
|
|
|
#[inline]
|
|
fn get_sparse_set_index(value: usize) -> Self {
|
|
Self(value)
|
|
}
|
|
}
|
|
|
|
/// A value describing a component or resource, which may or may not correspond to a Rust type.
|
|
#[derive(Clone)]
|
|
pub struct ComponentDescriptor {
|
|
name: DebugName,
|
|
// SAFETY: This must remain private. It must match the statically known StorageType of the
|
|
// associated rust component type if one exists.
|
|
storage_type: StorageType,
|
|
// SAFETY: This must remain private. It must only be set to "true" if this component is
|
|
// actually Send + Sync
|
|
is_send_and_sync: bool,
|
|
type_id: Option<TypeId>,
|
|
layout: Layout,
|
|
// SAFETY: this function must be safe to call with pointers pointing to items of the type
|
|
// this descriptor describes.
|
|
// None if the underlying type doesn't need to be dropped
|
|
drop: Option<for<'a> unsafe fn(OwningPtr<'a>)>,
|
|
mutable: bool,
|
|
clone_behavior: ComponentCloneBehavior,
|
|
}
|
|
|
|
// We need to ignore the `drop` field in our `Debug` impl
|
|
impl Debug for ComponentDescriptor {
|
|
fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
|
|
f.debug_struct("ComponentDescriptor")
|
|
.field("name", &self.name)
|
|
.field("storage_type", &self.storage_type)
|
|
.field("is_send_and_sync", &self.is_send_and_sync)
|
|
.field("type_id", &self.type_id)
|
|
.field("layout", &self.layout)
|
|
.field("mutable", &self.mutable)
|
|
.field("clone_behavior", &self.clone_behavior)
|
|
.finish()
|
|
}
|
|
}
|
|
|
|
impl ComponentDescriptor {
|
|
/// # Safety
|
|
///
|
|
/// `x` must point to a valid value of type `T`.
|
|
unsafe fn drop_ptr<T>(x: OwningPtr<'_>) {
|
|
// SAFETY: Contract is required to be upheld by the caller.
|
|
unsafe {
|
|
x.drop_as::<T>();
|
|
}
|
|
}
|
|
|
|
/// Create a new `ComponentDescriptor` for the type `T`.
|
|
pub fn new<T: Component>() -> Self {
|
|
Self {
|
|
name: DebugName::type_name::<T>(),
|
|
storage_type: T::STORAGE_TYPE,
|
|
is_send_and_sync: true,
|
|
type_id: Some(TypeId::of::<T>()),
|
|
layout: Layout::new::<T>(),
|
|
drop: needs_drop::<T>().then_some(Self::drop_ptr::<T> as _),
|
|
mutable: T::Mutability::MUTABLE,
|
|
clone_behavior: T::clone_behavior(),
|
|
}
|
|
}
|
|
|
|
/// Create a new `ComponentDescriptor`.
|
|
///
|
|
/// # Safety
|
|
/// - the `drop` fn must be usable on a pointer with a value of the layout `layout`
|
|
/// - the component type must be safe to access from any thread (Send + Sync in rust terms)
|
|
pub unsafe fn new_with_layout(
|
|
name: impl Into<Cow<'static, str>>,
|
|
storage_type: StorageType,
|
|
layout: Layout,
|
|
drop: Option<for<'a> unsafe fn(OwningPtr<'a>)>,
|
|
mutable: bool,
|
|
clone_behavior: ComponentCloneBehavior,
|
|
) -> Self {
|
|
Self {
|
|
name: name.into().into(),
|
|
storage_type,
|
|
is_send_and_sync: true,
|
|
type_id: None,
|
|
layout,
|
|
drop,
|
|
mutable,
|
|
clone_behavior,
|
|
}
|
|
}
|
|
|
|
/// Create a new `ComponentDescriptor` for a resource.
|
|
///
|
|
/// The [`StorageType`] for resources is always [`StorageType::Table`].
|
|
pub fn new_resource<T: Resource>() -> Self {
|
|
Self {
|
|
name: DebugName::type_name::<T>(),
|
|
// PERF: `SparseStorage` may actually be a more
|
|
// reasonable choice as `storage_type` for resources.
|
|
storage_type: StorageType::Table,
|
|
is_send_and_sync: true,
|
|
type_id: Some(TypeId::of::<T>()),
|
|
layout: Layout::new::<T>(),
|
|
drop: needs_drop::<T>().then_some(Self::drop_ptr::<T> as _),
|
|
mutable: true,
|
|
clone_behavior: ComponentCloneBehavior::Default,
|
|
}
|
|
}
|
|
|
|
fn new_non_send<T: Any>(storage_type: StorageType) -> Self {
|
|
Self {
|
|
name: DebugName::type_name::<T>(),
|
|
storage_type,
|
|
is_send_and_sync: false,
|
|
type_id: Some(TypeId::of::<T>()),
|
|
layout: Layout::new::<T>(),
|
|
drop: needs_drop::<T>().then_some(Self::drop_ptr::<T> as _),
|
|
mutable: true,
|
|
clone_behavior: ComponentCloneBehavior::Default,
|
|
}
|
|
}
|
|
|
|
/// Returns a value indicating the storage strategy for the current component.
|
|
#[inline]
|
|
pub fn storage_type(&self) -> StorageType {
|
|
self.storage_type
|
|
}
|
|
|
|
/// Returns the [`TypeId`] of the underlying component type.
|
|
/// Returns `None` if the component does not correspond to a Rust type.
|
|
#[inline]
|
|
pub fn type_id(&self) -> Option<TypeId> {
|
|
self.type_id
|
|
}
|
|
|
|
/// Returns the name of the current component.
|
|
#[inline]
|
|
pub fn name(&self) -> DebugName {
|
|
self.name.clone()
|
|
}
|
|
|
|
/// Returns whether this component is mutable.
|
|
#[inline]
|
|
pub fn mutable(&self) -> bool {
|
|
self.mutable
|
|
}
|
|
}
|
|
|
|
/// Function type that can be used to clone an entity.
|
|
pub type ComponentCloneFn = fn(&SourceComponent, &mut ComponentCloneCtx);
|
|
|
|
/// The clone behavior to use when cloning a [`Component`].
|
|
#[derive(Clone, Debug, Default, PartialEq, Eq)]
|
|
pub enum ComponentCloneBehavior {
|
|
/// Uses the default behavior (which is passed to [`ComponentCloneBehavior::resolve`])
|
|
#[default]
|
|
Default,
|
|
/// Do not clone this component.
|
|
Ignore,
|
|
/// Uses a custom [`ComponentCloneFn`].
|
|
Custom(ComponentCloneFn),
|
|
}
|
|
|
|
impl ComponentCloneBehavior {
|
|
/// Set clone handler based on `Clone` trait.
|
|
///
|
|
/// If set as a handler for a component that is not the same as the one used to create this handler, it will panic.
|
|
pub fn clone<C: Component + Clone>() -> Self {
|
|
Self::Custom(component_clone_via_clone::<C>)
|
|
}
|
|
|
|
/// Set clone handler based on `Reflect` trait.
|
|
#[cfg(feature = "bevy_reflect")]
|
|
pub fn reflect() -> Self {
|
|
Self::Custom(component_clone_via_reflect)
|
|
}
|
|
|
|
/// Returns the "global default"
|
|
pub fn global_default_fn() -> ComponentCloneFn {
|
|
#[cfg(feature = "bevy_reflect")]
|
|
return component_clone_via_reflect;
|
|
#[cfg(not(feature = "bevy_reflect"))]
|
|
return component_clone_ignore;
|
|
}
|
|
|
|
/// Resolves the [`ComponentCloneBehavior`] to a [`ComponentCloneFn`]. If [`ComponentCloneBehavior::Default`] is
|
|
/// specified, the given `default` function will be used.
|
|
pub fn resolve(&self, default: ComponentCloneFn) -> ComponentCloneFn {
|
|
match self {
|
|
ComponentCloneBehavior::Default => default,
|
|
ComponentCloneBehavior::Ignore => component_clone_ignore,
|
|
ComponentCloneBehavior::Custom(custom) => *custom,
|
|
}
|
|
}
|
|
}
|
|
|
|
/// A queued component registration.
|
|
struct QueuedRegistration {
|
|
registrator: Box<dyn FnOnce(&mut ComponentsRegistrator, ComponentId, ComponentDescriptor)>,
|
|
id: ComponentId,
|
|
descriptor: ComponentDescriptor,
|
|
}
|
|
|
|
impl QueuedRegistration {
|
|
/// Creates the [`QueuedRegistration`].
|
|
///
|
|
/// # Safety
|
|
///
|
|
/// [`ComponentId`] must be unique.
|
|
unsafe fn new(
|
|
id: ComponentId,
|
|
descriptor: ComponentDescriptor,
|
|
func: impl FnOnce(&mut ComponentsRegistrator, ComponentId, ComponentDescriptor) + 'static,
|
|
) -> Self {
|
|
Self {
|
|
registrator: Box::new(func),
|
|
id,
|
|
descriptor,
|
|
}
|
|
}
|
|
|
|
/// Performs the registration, returning the now valid [`ComponentId`].
|
|
fn register(self, registrator: &mut ComponentsRegistrator) -> ComponentId {
|
|
(self.registrator)(registrator, self.id, self.descriptor);
|
|
self.id
|
|
}
|
|
}
|
|
|
|
/// Allows queuing components to be registered.
|
|
#[derive(Default)]
|
|
pub struct QueuedComponents {
|
|
components: TypeIdMap<QueuedRegistration>,
|
|
resources: TypeIdMap<QueuedRegistration>,
|
|
dynamic_registrations: Vec<QueuedRegistration>,
|
|
}
|
|
|
|
impl Debug for QueuedComponents {
|
|
fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
|
|
let components = self
|
|
.components
|
|
.iter()
|
|
.map(|(type_id, queued)| (type_id, queued.id))
|
|
.collect::<Vec<_>>();
|
|
let resources = self
|
|
.resources
|
|
.iter()
|
|
.map(|(type_id, queued)| (type_id, queued.id))
|
|
.collect::<Vec<_>>();
|
|
let dynamic_registrations = self
|
|
.dynamic_registrations
|
|
.iter()
|
|
.map(|queued| queued.id)
|
|
.collect::<Vec<_>>();
|
|
write!(f, "components: {components:?}, resources: {resources:?}, dynamic_registrations: {dynamic_registrations:?}")
|
|
}
|
|
}
|
|
|
|
/// Generates [`ComponentId`]s.
|
|
#[derive(Debug, Default)]
|
|
pub struct ComponentIds {
|
|
next: bevy_platform::sync::atomic::AtomicUsize,
|
|
}
|
|
|
|
impl ComponentIds {
|
|
/// Peeks the next [`ComponentId`] to be generated without generating it.
|
|
pub fn peek(&self) -> ComponentId {
|
|
ComponentId(
|
|
self.next
|
|
.load(bevy_platform::sync::atomic::Ordering::Relaxed),
|
|
)
|
|
}
|
|
|
|
/// Generates and returns the next [`ComponentId`].
|
|
pub fn next(&self) -> ComponentId {
|
|
ComponentId(
|
|
self.next
|
|
.fetch_add(1, bevy_platform::sync::atomic::Ordering::Relaxed),
|
|
)
|
|
}
|
|
|
|
/// Peeks the next [`ComponentId`] to be generated without generating it.
|
|
pub fn peek_mut(&mut self) -> ComponentId {
|
|
ComponentId(*self.next.get_mut())
|
|
}
|
|
|
|
/// Generates and returns the next [`ComponentId`].
|
|
pub fn next_mut(&mut self) -> ComponentId {
|
|
let id = self.next.get_mut();
|
|
let result = ComponentId(*id);
|
|
*id += 1;
|
|
result
|
|
}
|
|
|
|
/// Returns the number of [`ComponentId`]s generated.
|
|
pub fn len(&self) -> usize {
|
|
self.peek().0
|
|
}
|
|
|
|
/// Returns true if and only if no ids have been generated.
|
|
pub fn is_empty(&self) -> bool {
|
|
self.len() == 0
|
|
}
|
|
}
|
|
|
|
/// A type that enables queuing registration in [`Components`].
|
|
///
|
|
/// # Note
|
|
///
|
|
/// These queued registrations return [`ComponentId`]s.
|
|
/// These ids are not yet valid, but they will become valid
|
|
/// when either [`ComponentsRegistrator::apply_queued_registrations`] is called or the same registration is made directly.
|
|
/// In either case, the returned [`ComponentId`]s will be correct, but they are not correct yet.
|
|
///
|
|
/// Generally, that means these [`ComponentId`]s can be safely used for read-only purposes.
|
|
/// Modifying the contents of the world through these [`ComponentId`]s directly without waiting for them to be fully registered
|
|
/// and without then confirming that they have been fully registered is not supported.
|
|
/// Hence, extra care is needed with these [`ComponentId`]s to ensure all safety rules are followed.
|
|
///
|
|
/// As a rule of thumb, if you have mutable access to [`ComponentsRegistrator`], prefer to use that instead.
|
|
/// Use this only if you need to know the id of a component but do not need to modify the contents of the world based on that id.
|
|
#[derive(Clone, Copy)]
|
|
pub struct ComponentsQueuedRegistrator<'w> {
|
|
components: &'w Components,
|
|
ids: &'w ComponentIds,
|
|
}
|
|
|
|
impl Deref for ComponentsQueuedRegistrator<'_> {
|
|
type Target = Components;
|
|
|
|
fn deref(&self) -> &Self::Target {
|
|
self.components
|
|
}
|
|
}
|
|
|
|
impl<'w> ComponentsQueuedRegistrator<'w> {
|
|
/// Constructs a new [`ComponentsQueuedRegistrator`].
|
|
///
|
|
/// # Safety
|
|
///
|
|
/// The [`Components`] and [`ComponentIds`] must match.
|
|
/// For example, they must be from the same world.
|
|
pub unsafe fn new(components: &'w Components, ids: &'w ComponentIds) -> Self {
|
|
Self { components, ids }
|
|
}
|
|
|
|
/// Queues this function to run as a component registrator.
|
|
///
|
|
/// # Safety
|
|
///
|
|
/// The [`TypeId`] must not already be registered or queued as a component.
|
|
unsafe fn force_register_arbitrary_component(
|
|
&self,
|
|
type_id: TypeId,
|
|
descriptor: ComponentDescriptor,
|
|
func: impl FnOnce(&mut ComponentsRegistrator, ComponentId, ComponentDescriptor) + 'static,
|
|
) -> ComponentId {
|
|
let id = self.ids.next();
|
|
self.components
|
|
.queued
|
|
.write()
|
|
.unwrap_or_else(PoisonError::into_inner)
|
|
.components
|
|
.insert(
|
|
type_id,
|
|
// SAFETY: The id was just generated.
|
|
unsafe { QueuedRegistration::new(id, descriptor, func) },
|
|
);
|
|
id
|
|
}
|
|
|
|
/// Queues this function to run as a resource registrator.
|
|
///
|
|
/// # Safety
|
|
///
|
|
/// The [`TypeId`] must not already be registered or queued as a resource.
|
|
unsafe fn force_register_arbitrary_resource(
|
|
&self,
|
|
type_id: TypeId,
|
|
descriptor: ComponentDescriptor,
|
|
func: impl FnOnce(&mut ComponentsRegistrator, ComponentId, ComponentDescriptor) + 'static,
|
|
) -> ComponentId {
|
|
let id = self.ids.next();
|
|
self.components
|
|
.queued
|
|
.write()
|
|
.unwrap_or_else(PoisonError::into_inner)
|
|
.resources
|
|
.insert(
|
|
type_id,
|
|
// SAFETY: The id was just generated.
|
|
unsafe { QueuedRegistration::new(id, descriptor, func) },
|
|
);
|
|
id
|
|
}
|
|
|
|
/// Queues this function to run as a dynamic registrator.
|
|
fn force_register_arbitrary_dynamic(
|
|
&self,
|
|
descriptor: ComponentDescriptor,
|
|
func: impl FnOnce(&mut ComponentsRegistrator, ComponentId, ComponentDescriptor) + 'static,
|
|
) -> ComponentId {
|
|
let id = self.ids.next();
|
|
self.components
|
|
.queued
|
|
.write()
|
|
.unwrap_or_else(PoisonError::into_inner)
|
|
.dynamic_registrations
|
|
.push(
|
|
// SAFETY: The id was just generated.
|
|
unsafe { QueuedRegistration::new(id, descriptor, func) },
|
|
);
|
|
id
|
|
}
|
|
|
|
/// This is a queued version of [`ComponentsRegistrator::register_component`].
|
|
/// This will reserve an id and queue the registration.
|
|
/// These registrations will be carried out at the next opportunity.
|
|
///
|
|
/// If this has already been registered or queued, this returns the previous [`ComponentId`].
|
|
///
|
|
/// # Note
|
|
///
|
|
/// Technically speaking, the returned [`ComponentId`] is not valid, but it will become valid later.
|
|
/// See type level docs for details.
|
|
#[inline]
|
|
pub fn queue_register_component<T: Component>(&self) -> ComponentId {
|
|
self.component_id::<T>().unwrap_or_else(|| {
|
|
// SAFETY: We just checked that this type was not in the queue.
|
|
unsafe {
|
|
self.force_register_arbitrary_component(
|
|
TypeId::of::<T>(),
|
|
ComponentDescriptor::new::<T>(),
|
|
|registrator, id, _descriptor| {
|
|
// SAFETY: We just checked that this is not currently registered or queued, and if it was registered since, this would have been dropped from the queue.
|
|
#[expect(unused_unsafe, reason = "More precise to specify.")]
|
|
unsafe {
|
|
registrator.register_component_unchecked::<T>(&mut Vec::new(), id);
|
|
}
|
|
},
|
|
)
|
|
}
|
|
})
|
|
}
|
|
|
|
/// This is a queued version of [`ComponentsRegistrator::register_component_with_descriptor`].
|
|
/// This will reserve an id and queue the registration.
|
|
/// These registrations will be carried out at the next opportunity.
|
|
///
|
|
/// # Note
|
|
///
|
|
/// Technically speaking, the returned [`ComponentId`] is not valid, but it will become valid later.
|
|
/// See type level docs for details.
|
|
#[inline]
|
|
pub fn queue_register_component_with_descriptor(
|
|
&self,
|
|
descriptor: ComponentDescriptor,
|
|
) -> ComponentId {
|
|
self.force_register_arbitrary_dynamic(descriptor, |registrator, id, descriptor| {
|
|
// SAFETY: Id uniqueness handled by caller.
|
|
unsafe {
|
|
registrator.register_component_inner(id, descriptor);
|
|
}
|
|
})
|
|
}
|
|
|
|
/// This is a queued version of [`ComponentsRegistrator::register_resource`].
|
|
/// This will reserve an id and queue the registration.
|
|
/// These registrations will be carried out at the next opportunity.
|
|
///
|
|
/// If this has already been registered or queued, this returns the previous [`ComponentId`].
|
|
///
|
|
/// # Note
|
|
///
|
|
/// Technically speaking, the returned [`ComponentId`] is not valid, but it will become valid later.
|
|
/// See type level docs for details.
|
|
#[inline]
|
|
pub fn queue_register_resource<T: Resource>(&self) -> ComponentId {
|
|
let type_id = TypeId::of::<T>();
|
|
self.get_resource_id(type_id).unwrap_or_else(|| {
|
|
// SAFETY: We just checked that this type was not in the queue.
|
|
unsafe {
|
|
self.force_register_arbitrary_resource(
|
|
type_id,
|
|
ComponentDescriptor::new_resource::<T>(),
|
|
move |registrator, id, descriptor| {
|
|
// SAFETY: We just checked that this is not currently registered or queued, and if it was registered since, this would have been dropped from the queue.
|
|
// SAFETY: Id uniqueness handled by caller, and the type_id matches descriptor.
|
|
#[expect(unused_unsafe, reason = "More precise to specify.")]
|
|
unsafe {
|
|
registrator.register_resource_unchecked(type_id, id, descriptor);
|
|
}
|
|
},
|
|
)
|
|
}
|
|
})
|
|
}
|
|
|
|
/// This is a queued version of [`ComponentsRegistrator::register_non_send`].
|
|
/// This will reserve an id and queue the registration.
|
|
/// These registrations will be carried out at the next opportunity.
|
|
///
|
|
/// If this has already been registered or queued, this returns the previous [`ComponentId`].
|
|
///
|
|
/// # Note
|
|
///
|
|
/// Technically speaking, the returned [`ComponentId`] is not valid, but it will become valid later.
|
|
/// See type level docs for details.
|
|
#[inline]
|
|
pub fn queue_register_non_send<T: Any>(&self) -> ComponentId {
|
|
let type_id = TypeId::of::<T>();
|
|
self.get_resource_id(type_id).unwrap_or_else(|| {
|
|
// SAFETY: We just checked that this type was not in the queue.
|
|
unsafe {
|
|
self.force_register_arbitrary_resource(
|
|
type_id,
|
|
ComponentDescriptor::new_non_send::<T>(StorageType::default()),
|
|
move |registrator, id, descriptor| {
|
|
// SAFETY: We just checked that this is not currently registered or queued, and if it was registered since, this would have been dropped from the queue.
|
|
// SAFETY: Id uniqueness handled by caller, and the type_id matches descriptor.
|
|
#[expect(unused_unsafe, reason = "More precise to specify.")]
|
|
unsafe {
|
|
registrator.register_resource_unchecked(type_id, id, descriptor);
|
|
}
|
|
},
|
|
)
|
|
}
|
|
})
|
|
}
|
|
|
|
/// This is a queued version of [`ComponentsRegistrator::register_resource_with_descriptor`].
|
|
/// This will reserve an id and queue the registration.
|
|
/// These registrations will be carried out at the next opportunity.
|
|
///
|
|
/// # Note
|
|
///
|
|
/// Technically speaking, the returned [`ComponentId`] is not valid, but it will become valid later.
|
|
/// See type level docs for details.
|
|
#[inline]
|
|
pub fn queue_register_resource_with_descriptor(
|
|
&self,
|
|
descriptor: ComponentDescriptor,
|
|
) -> ComponentId {
|
|
self.force_register_arbitrary_dynamic(descriptor, |registrator, id, descriptor| {
|
|
// SAFETY: Id uniqueness handled by caller.
|
|
unsafe {
|
|
registrator.register_component_inner(id, descriptor);
|
|
}
|
|
})
|
|
}
|
|
}
|
|
|
|
/// A [`Components`] wrapper that enables additional features, like registration.
|
|
pub struct ComponentsRegistrator<'w> {
|
|
components: &'w mut Components,
|
|
ids: &'w mut ComponentIds,
|
|
}
|
|
|
|
impl Deref for ComponentsRegistrator<'_> {
|
|
type Target = Components;
|
|
|
|
fn deref(&self) -> &Self::Target {
|
|
self.components
|
|
}
|
|
}
|
|
|
|
impl DerefMut for ComponentsRegistrator<'_> {
|
|
fn deref_mut(&mut self) -> &mut Self::Target {
|
|
self.components
|
|
}
|
|
}
|
|
|
|
impl<'w> ComponentsRegistrator<'w> {
|
|
/// Constructs a new [`ComponentsRegistrator`].
|
|
///
|
|
/// # Safety
|
|
///
|
|
/// The [`Components`] and [`ComponentIds`] must match.
|
|
/// For example, they must be from the same world.
|
|
pub unsafe fn new(components: &'w mut Components, ids: &'w mut ComponentIds) -> Self {
|
|
Self { components, ids }
|
|
}
|
|
|
|
/// Converts this [`ComponentsRegistrator`] into a [`ComponentsQueuedRegistrator`].
|
|
/// This is intended for use to pass this value to a function that requires [`ComponentsQueuedRegistrator`].
|
|
/// It is generally not a good idea to queue a registration when you can instead register directly on this type.
|
|
pub fn as_queued(&self) -> ComponentsQueuedRegistrator<'_> {
|
|
// SAFETY: ensured by the caller that created self.
|
|
unsafe { ComponentsQueuedRegistrator::new(self.components, self.ids) }
|
|
}
|
|
|
|
/// Applies every queued registration.
|
|
/// This ensures that every valid [`ComponentId`] is registered,
|
|
/// enabling retrieving [`ComponentInfo`], etc.
|
|
pub fn apply_queued_registrations(&mut self) {
|
|
if !self.any_queued_mut() {
|
|
return;
|
|
}
|
|
|
|
// Note:
|
|
//
|
|
// This is not just draining the queue. We need to empty the queue without removing the information from `Components`.
|
|
// If we drained directly, we could break invariance.
|
|
//
|
|
// For example, say `ComponentA` and `ComponentB` are queued, and `ComponentA` requires `ComponentB`.
|
|
// If we drain directly, and `ComponentA` was the first to be registered, then, when `ComponentA`
|
|
// registers `ComponentB` in `Component::register_required_components`,
|
|
// `Components` will not know that `ComponentB` was queued
|
|
// (since it will have been drained from the queue.)
|
|
// If that happened, `Components` would assign a new `ComponentId` to `ComponentB`
|
|
// which would be *different* than the id it was assigned in the queue.
|
|
// Then, when the drain iterator gets to `ComponentB`,
|
|
// it would be unsafely registering `ComponentB`, which is already registered.
|
|
//
|
|
// As a result, we need to pop from each queue one by one instead of draining.
|
|
|
|
// components
|
|
while let Some(registrator) = {
|
|
let queued = self
|
|
.components
|
|
.queued
|
|
.get_mut()
|
|
.unwrap_or_else(PoisonError::into_inner);
|
|
queued.components.keys().next().copied().map(|type_id| {
|
|
// SAFETY: the id just came from a valid iterator.
|
|
unsafe { queued.components.remove(&type_id).debug_checked_unwrap() }
|
|
})
|
|
} {
|
|
registrator.register(self);
|
|
}
|
|
|
|
// resources
|
|
while let Some(registrator) = {
|
|
let queued = self
|
|
.components
|
|
.queued
|
|
.get_mut()
|
|
.unwrap_or_else(PoisonError::into_inner);
|
|
queued.resources.keys().next().copied().map(|type_id| {
|
|
// SAFETY: the id just came from a valid iterator.
|
|
unsafe { queued.resources.remove(&type_id).debug_checked_unwrap() }
|
|
})
|
|
} {
|
|
registrator.register(self);
|
|
}
|
|
|
|
// dynamic
|
|
let queued = &mut self
|
|
.components
|
|
.queued
|
|
.get_mut()
|
|
.unwrap_or_else(PoisonError::into_inner);
|
|
if !queued.dynamic_registrations.is_empty() {
|
|
for registrator in core::mem::take(&mut queued.dynamic_registrations) {
|
|
registrator.register(self);
|
|
}
|
|
}
|
|
}
|
|
|
|
/// Registers a [`Component`] of type `T` with this instance.
|
|
/// If a component of this type has already been registered, this will return
|
|
/// the ID of the pre-existing component.
|
|
///
|
|
/// # See also
|
|
///
|
|
/// * [`Components::component_id()`]
|
|
/// * [`ComponentsRegistrator::register_component_with_descriptor()`]
|
|
#[inline]
|
|
pub fn register_component<T: Component>(&mut self) -> ComponentId {
|
|
self.register_component_checked::<T>(&mut Vec::new())
|
|
}
|
|
|
|
/// Same as [`Self::register_component_unchecked`] but keeps a checks for safety.
|
|
#[inline]
|
|
fn register_component_checked<T: Component>(
|
|
&mut self,
|
|
recursion_check_stack: &mut Vec<ComponentId>,
|
|
) -> ComponentId {
|
|
let type_id = TypeId::of::<T>();
|
|
if let Some(id) = self.indices.get(&type_id) {
|
|
return *id;
|
|
}
|
|
|
|
if let Some(registrator) = self
|
|
.components
|
|
.queued
|
|
.get_mut()
|
|
.unwrap_or_else(PoisonError::into_inner)
|
|
.components
|
|
.remove(&type_id)
|
|
{
|
|
// If we are trying to register something that has already been queued, we respect the queue.
|
|
// Just like if we are trying to register something that already is, we respect the first registration.
|
|
return registrator.register(self);
|
|
}
|
|
|
|
let id = self.ids.next_mut();
|
|
// SAFETY: The component is not currently registered, and the id is fresh.
|
|
unsafe {
|
|
self.register_component_unchecked::<T>(recursion_check_stack, id);
|
|
}
|
|
id
|
|
}
|
|
|
|
/// # Safety
|
|
///
|
|
/// Neither this component, nor its id may be registered or queued. This must be a new registration.
|
|
#[inline]
|
|
unsafe fn register_component_unchecked<T: Component>(
|
|
&mut self,
|
|
recursion_check_stack: &mut Vec<ComponentId>,
|
|
id: ComponentId,
|
|
) {
|
|
// SAFETY: ensured by caller.
|
|
unsafe {
|
|
self.register_component_inner(id, ComponentDescriptor::new::<T>());
|
|
}
|
|
let type_id = TypeId::of::<T>();
|
|
let prev = self.indices.insert(type_id, id);
|
|
debug_assert!(prev.is_none());
|
|
|
|
let mut required_components = RequiredComponents::default();
|
|
T::register_required_components(
|
|
id,
|
|
self,
|
|
&mut required_components,
|
|
0,
|
|
recursion_check_stack,
|
|
);
|
|
// SAFETY: we just inserted it in `register_component_inner`
|
|
let info = unsafe {
|
|
&mut self
|
|
.components
|
|
.components
|
|
.get_mut(id.0)
|
|
.debug_checked_unwrap()
|
|
.as_mut()
|
|
.debug_checked_unwrap()
|
|
};
|
|
|
|
info.hooks.update_from_component::<T>();
|
|
|
|
info.required_components = required_components;
|
|
}
|
|
|
|
/// Registers a component described by `descriptor`.
|
|
///
|
|
/// # Note
|
|
///
|
|
/// If this method is called multiple times with identical descriptors, a distinct [`ComponentId`]
|
|
/// will be created for each one.
|
|
///
|
|
/// # See also
|
|
///
|
|
/// * [`Components::component_id()`]
|
|
/// * [`ComponentsRegistrator::register_component()`]
|
|
#[inline]
|
|
pub fn register_component_with_descriptor(
|
|
&mut self,
|
|
descriptor: ComponentDescriptor,
|
|
) -> ComponentId {
|
|
let id = self.ids.next_mut();
|
|
// SAFETY: The id is fresh.
|
|
unsafe {
|
|
self.register_component_inner(id, descriptor);
|
|
}
|
|
id
|
|
}
|
|
|
|
// NOTE: This should maybe be private, but it is currently public so that `bevy_ecs_macros` can use it.
|
|
// We can't directly move this there either, because this uses `Components::get_required_by_mut`,
|
|
// which is private, and could be equally risky to expose to users.
|
|
/// Registers the given component `R` and [required components] inherited from it as required by `T`,
|
|
/// and adds `T` to their lists of requirees.
|
|
///
|
|
/// The given `inheritance_depth` determines how many levels of inheritance deep the requirement is.
|
|
/// A direct requirement has a depth of `0`, and each level of inheritance increases the depth by `1`.
|
|
/// Lower depths are more specific requirements, and can override existing less specific registrations.
|
|
///
|
|
/// The `recursion_check_stack` allows checking whether this component tried to register itself as its
|
|
/// own (indirect) required component.
|
|
///
|
|
/// This method does *not* register any components as required by components that require `T`.
|
|
///
|
|
/// Only use this method if you know what you are doing. In most cases, you should instead use [`World::register_required_components`],
|
|
/// or the equivalent method in `bevy_app::App`.
|
|
///
|
|
/// [required component]: Component#required-components
|
|
#[doc(hidden)]
|
|
pub fn register_required_components_manual<T: Component, R: Component>(
|
|
&mut self,
|
|
required_components: &mut RequiredComponents,
|
|
constructor: fn() -> R,
|
|
inheritance_depth: u16,
|
|
recursion_check_stack: &mut Vec<ComponentId>,
|
|
) {
|
|
let requiree = self.register_component_checked::<T>(recursion_check_stack);
|
|
let required = self.register_component_checked::<R>(recursion_check_stack);
|
|
|
|
// SAFETY: We just created the components.
|
|
unsafe {
|
|
self.register_required_components_manual_unchecked::<R>(
|
|
requiree,
|
|
required,
|
|
required_components,
|
|
constructor,
|
|
inheritance_depth,
|
|
);
|
|
}
|
|
}
|
|
|
|
/// Registers a [`Resource`] of type `T` with this instance.
|
|
/// If a resource of this type has already been registered, this will return
|
|
/// the ID of the pre-existing resource.
|
|
///
|
|
/// # See also
|
|
///
|
|
/// * [`Components::resource_id()`]
|
|
/// * [`ComponentsRegistrator::register_resource_with_descriptor()`]
|
|
#[inline]
|
|
pub fn register_resource<T: Resource>(&mut self) -> ComponentId {
|
|
// SAFETY: The [`ComponentDescriptor`] matches the [`TypeId`]
|
|
unsafe {
|
|
self.register_resource_with(TypeId::of::<T>(), || {
|
|
ComponentDescriptor::new_resource::<T>()
|
|
})
|
|
}
|
|
}
|
|
|
|
/// Registers a [non-send resource](crate::system::NonSend) of type `T` with this instance.
|
|
/// If a resource of this type has already been registered, this will return
|
|
/// the ID of the pre-existing resource.
|
|
#[inline]
|
|
pub fn register_non_send<T: Any>(&mut self) -> ComponentId {
|
|
// SAFETY: The [`ComponentDescriptor`] matches the [`TypeId`]
|
|
unsafe {
|
|
self.register_resource_with(TypeId::of::<T>(), || {
|
|
ComponentDescriptor::new_non_send::<T>(StorageType::default())
|
|
})
|
|
}
|
|
}
|
|
|
|
/// Same as [`Components::register_resource_unchecked`] but handles safety.
|
|
///
|
|
/// # Safety
|
|
///
|
|
/// The [`ComponentDescriptor`] must match the [`TypeId`].
|
|
#[inline]
|
|
unsafe fn register_resource_with(
|
|
&mut self,
|
|
type_id: TypeId,
|
|
descriptor: impl FnOnce() -> ComponentDescriptor,
|
|
) -> ComponentId {
|
|
if let Some(id) = self.resource_indices.get(&type_id) {
|
|
return *id;
|
|
}
|
|
|
|
if let Some(registrator) = self
|
|
.components
|
|
.queued
|
|
.get_mut()
|
|
.unwrap_or_else(PoisonError::into_inner)
|
|
.resources
|
|
.remove(&type_id)
|
|
{
|
|
// If we are trying to register something that has already been queued, we respect the queue.
|
|
// Just like if we are trying to register something that already is, we respect the first registration.
|
|
return registrator.register(self);
|
|
}
|
|
|
|
let id = self.ids.next_mut();
|
|
// SAFETY: The resource is not currently registered, the id is fresh, and the [`ComponentDescriptor`] matches the [`TypeId`]
|
|
unsafe {
|
|
self.register_resource_unchecked(type_id, id, descriptor());
|
|
}
|
|
id
|
|
}
|
|
|
|
/// Registers a [`Resource`] described by `descriptor`.
|
|
///
|
|
/// # Note
|
|
///
|
|
/// If this method is called multiple times with identical descriptors, a distinct [`ComponentId`]
|
|
/// will be created for each one.
|
|
///
|
|
/// # See also
|
|
///
|
|
/// * [`Components::resource_id()`]
|
|
/// * [`ComponentsRegistrator::register_resource()`]
|
|
#[inline]
|
|
pub fn register_resource_with_descriptor(
|
|
&mut self,
|
|
descriptor: ComponentDescriptor,
|
|
) -> ComponentId {
|
|
let id = self.ids.next_mut();
|
|
// SAFETY: The id is fresh.
|
|
unsafe {
|
|
self.register_component_inner(id, descriptor);
|
|
}
|
|
id
|
|
}
|
|
}
|
|
|
|
/// Stores metadata associated with each kind of [`Component`] in a given [`World`].
|
|
#[derive(Debug, Default)]
|
|
pub struct Components {
|
|
components: Vec<Option<ComponentInfo>>,
|
|
indices: TypeIdMap<ComponentId>,
|
|
resource_indices: TypeIdMap<ComponentId>,
|
|
/// A lookup for the entities on which resources are stored.
|
|
/// It uses ComponentIds instead of TypeIds for untyped APIs
|
|
pub(crate) resource_entities: HashMap<ComponentId, Entity>,
|
|
// This is kept internal and local to verify that no deadlocks can occor.
|
|
queued: bevy_platform::sync::RwLock<QueuedComponents>,
|
|
}
|
|
|
|
impl Components {
|
|
/// This registers any descriptor, component or resource.
|
|
///
|
|
/// # Safety
|
|
///
|
|
/// The id must have never been registered before. This must be a fresh registration.
|
|
#[inline]
|
|
unsafe fn register_component_inner(
|
|
&mut self,
|
|
id: ComponentId,
|
|
descriptor: ComponentDescriptor,
|
|
) {
|
|
let info = ComponentInfo::new(id, descriptor);
|
|
let least_len = id.0 + 1;
|
|
if self.components.len() < least_len {
|
|
self.components.resize_with(least_len, || None);
|
|
}
|
|
// SAFETY: We just extended the vec to make this index valid.
|
|
let slot = unsafe { self.components.get_mut(id.0).debug_checked_unwrap() };
|
|
// Caller ensures id is unique
|
|
debug_assert!(slot.is_none());
|
|
*slot = Some(info);
|
|
}
|
|
|
|
/// Returns the number of components registered or queued with this instance.
|
|
#[inline]
|
|
pub fn len(&self) -> usize {
|
|
self.num_queued() + self.num_registered()
|
|
}
|
|
|
|
/// Returns `true` if there are no components registered or queued with this instance. Otherwise, this returns `false`.
|
|
#[inline]
|
|
pub fn is_empty(&self) -> bool {
|
|
self.len() == 0
|
|
}
|
|
|
|
/// Returns the number of components registered with this instance.
|
|
#[inline]
|
|
pub fn num_queued(&self) -> usize {
|
|
let queued = self.queued.read().unwrap_or_else(PoisonError::into_inner);
|
|
queued.components.len() + queued.dynamic_registrations.len() + queued.resources.len()
|
|
}
|
|
|
|
/// Returns `true` if there are any components registered with this instance. Otherwise, this returns `false`.
|
|
#[inline]
|
|
pub fn any_queued(&self) -> bool {
|
|
self.num_queued() > 0
|
|
}
|
|
|
|
/// A faster version of [`Self::num_queued`].
|
|
#[inline]
|
|
pub fn num_queued_mut(&mut self) -> usize {
|
|
let queued = self
|
|
.queued
|
|
.get_mut()
|
|
.unwrap_or_else(PoisonError::into_inner);
|
|
queued.components.len() + queued.dynamic_registrations.len() + queued.resources.len()
|
|
}
|
|
|
|
/// A faster version of [`Self::any_queued`].
|
|
#[inline]
|
|
pub fn any_queued_mut(&mut self) -> bool {
|
|
self.num_queued_mut() > 0
|
|
}
|
|
|
|
/// Returns the number of components registered with this instance.
|
|
#[inline]
|
|
pub fn num_registered(&self) -> usize {
|
|
self.components.len()
|
|
}
|
|
|
|
/// Returns `true` if there are any components registered with this instance. Otherwise, this returns `false`.
|
|
#[inline]
|
|
pub fn any_registered(&self) -> bool {
|
|
self.num_registered() > 0
|
|
}
|
|
|
|
/// Gets the metadata associated with the given component, if it is registered.
|
|
/// This will return `None` if the id is not registered or is queued.
|
|
///
|
|
/// This will return an incorrect result if `id` did not come from the same world as `self`. It may return `None` or a garbage value.
|
|
#[inline]
|
|
pub fn get_info(&self, id: ComponentId) -> Option<&ComponentInfo> {
|
|
self.components.get(id.0).and_then(|info| info.as_ref())
|
|
}
|
|
|
|
/// Gets the [`ComponentDescriptor`] of the component with this [`ComponentId`] if it is present.
|
|
/// This will return `None` only if the id is neither registered nor queued to be registered.
|
|
///
|
|
/// Currently, the [`Cow`] will be [`Cow::Owned`] if and only if the component is queued. It will be [`Cow::Borrowed`] otherwise.
|
|
///
|
|
/// This will return an incorrect result if `id` did not come from the same world as `self`. It may return `None` or a garbage value.
|
|
#[inline]
|
|
pub fn get_descriptor<'a>(&'a self, id: ComponentId) -> Option<Cow<'a, ComponentDescriptor>> {
|
|
self.components
|
|
.get(id.0)
|
|
.and_then(|info| info.as_ref().map(|info| Cow::Borrowed(&info.descriptor)))
|
|
.or_else(|| {
|
|
let queued = self.queued.read().unwrap_or_else(PoisonError::into_inner);
|
|
// first check components, then resources, then dynamic
|
|
queued
|
|
.components
|
|
.values()
|
|
.chain(queued.resources.values())
|
|
.chain(queued.dynamic_registrations.iter())
|
|
.find(|queued| queued.id == id)
|
|
.map(|queued| Cow::Owned(queued.descriptor.clone()))
|
|
})
|
|
}
|
|
|
|
/// Gets the name of the component with this [`ComponentId`] if it is present.
|
|
/// This will return `None` only if the id is neither registered nor queued to be registered.
|
|
///
|
|
/// This will return an incorrect result if `id` did not come from the same world as `self`. It may return `None` or a garbage value.
|
|
#[inline]
|
|
pub fn get_name<'a>(&'a self, id: ComponentId) -> Option<DebugName> {
|
|
self.components
|
|
.get(id.0)
|
|
.and_then(|info| info.as_ref().map(|info| info.descriptor.name()))
|
|
.or_else(|| {
|
|
let queued = self.queued.read().unwrap_or_else(PoisonError::into_inner);
|
|
// first check components, then resources, then dynamic
|
|
queued
|
|
.components
|
|
.values()
|
|
.chain(queued.resources.values())
|
|
.chain(queued.dynamic_registrations.iter())
|
|
.find(|queued| queued.id == id)
|
|
.map(|queued| queued.descriptor.name.clone())
|
|
})
|
|
}
|
|
|
|
/// Gets the metadata associated with the given component.
|
|
/// # Safety
|
|
///
|
|
/// `id` must be a valid and fully registered [`ComponentId`].
|
|
#[inline]
|
|
pub unsafe fn get_info_unchecked(&self, id: ComponentId) -> &ComponentInfo {
|
|
// SAFETY: The caller ensures `id` is valid.
|
|
unsafe {
|
|
self.components
|
|
.get(id.0)
|
|
.debug_checked_unwrap()
|
|
.as_ref()
|
|
.debug_checked_unwrap()
|
|
}
|
|
}
|
|
|
|
#[inline]
|
|
pub(crate) fn get_hooks_mut(&mut self, id: ComponentId) -> Option<&mut ComponentHooks> {
|
|
self.components
|
|
.get_mut(id.0)
|
|
.and_then(|info| info.as_mut().map(|info| &mut info.hooks))
|
|
}
|
|
|
|
#[inline]
|
|
pub(crate) fn get_required_components_mut(
|
|
&mut self,
|
|
id: ComponentId,
|
|
) -> Option<&mut RequiredComponents> {
|
|
self.components
|
|
.get_mut(id.0)
|
|
.and_then(|info| info.as_mut().map(|info| &mut info.required_components))
|
|
}
|
|
|
|
/// Registers the given component `R` and [required components] inherited from it as required by `T`.
|
|
///
|
|
/// When `T` is added to an entity, `R` will also be added if it was not already provided.
|
|
/// The given `constructor` will be used for the creation of `R`.
|
|
///
|
|
/// [required components]: Component#required-components
|
|
///
|
|
/// # Safety
|
|
///
|
|
/// The given component IDs `required` and `requiree` must be valid.
|
|
///
|
|
/// # Errors
|
|
///
|
|
/// Returns a [`RequiredComponentsError`] if the `required` component is already a directly required component for the `requiree`.
|
|
///
|
|
/// Indirect requirements through other components are allowed. In those cases, the more specific
|
|
/// registration will be used.
|
|
pub(crate) unsafe fn register_required_components<R: Component>(
|
|
&mut self,
|
|
requiree: ComponentId,
|
|
required: ComponentId,
|
|
constructor: fn() -> R,
|
|
) -> Result<(), RequiredComponentsError> {
|
|
// SAFETY: The caller ensures that the `requiree` is valid.
|
|
let required_components = unsafe {
|
|
self.get_required_components_mut(requiree)
|
|
.debug_checked_unwrap()
|
|
};
|
|
|
|
// Cannot directly require the same component twice.
|
|
if required_components
|
|
.0
|
|
.get(&required)
|
|
.is_some_and(|c| c.inheritance_depth == 0)
|
|
{
|
|
return Err(RequiredComponentsError::DuplicateRegistration(
|
|
requiree, required,
|
|
));
|
|
}
|
|
|
|
// Register the required component for the requiree.
|
|
// This is a direct requirement with a depth of `0`.
|
|
required_components.register_by_id(required, constructor, 0);
|
|
|
|
// Add the requiree to the list of components that require the required component.
|
|
// SAFETY: The component is in the list of required components, so it must exist already.
|
|
let required_by = unsafe { self.get_required_by_mut(required).debug_checked_unwrap() };
|
|
required_by.insert(requiree);
|
|
|
|
let mut required_components_tmp = RequiredComponents::default();
|
|
// SAFETY: The caller ensures that the `requiree` and `required` components are valid.
|
|
let inherited_requirements = unsafe {
|
|
self.register_inherited_required_components(
|
|
requiree,
|
|
required,
|
|
&mut required_components_tmp,
|
|
)
|
|
};
|
|
|
|
// SAFETY: The caller ensures that the `requiree` is valid.
|
|
let required_components = unsafe {
|
|
self.get_required_components_mut(requiree)
|
|
.debug_checked_unwrap()
|
|
};
|
|
required_components.0.extend(required_components_tmp.0);
|
|
|
|
// Propagate the new required components up the chain to all components that require the requiree.
|
|
if let Some(required_by) = self
|
|
.get_required_by(requiree)
|
|
.map(|set| set.iter().copied().collect::<SmallVec<[ComponentId; 8]>>())
|
|
{
|
|
// `required` is now required by anything that `requiree` was required by.
|
|
self.get_required_by_mut(required)
|
|
.unwrap()
|
|
.extend(required_by.iter().copied());
|
|
for &required_by_id in required_by.iter() {
|
|
// SAFETY: The component is in the list of required components, so it must exist already.
|
|
let required_components = unsafe {
|
|
self.get_required_components_mut(required_by_id)
|
|
.debug_checked_unwrap()
|
|
};
|
|
|
|
// Register the original required component in the "parent" of the requiree.
|
|
// The inheritance depth is 1 deeper than the `requiree` wrt `required_by_id`.
|
|
let depth = required_components.0.get(&requiree).expect("requiree is required by required_by_id, so its required_components must include requiree").inheritance_depth;
|
|
required_components.register_by_id(required, constructor, depth + 1);
|
|
|
|
for (component_id, component) in inherited_requirements.iter() {
|
|
// Register the required component.
|
|
// The inheritance depth of inherited components is whatever the requiree's
|
|
// depth is relative to `required_by_id`, plus the inheritance depth of the
|
|
// inherited component relative to the requiree, plus 1 to account for the
|
|
// requiree in between.
|
|
// SAFETY: Component ID and constructor match the ones on the original requiree.
|
|
// The original requiree is responsible for making sure the registration is safe.
|
|
unsafe {
|
|
required_components.register_dynamic_with(
|
|
*component_id,
|
|
component.inheritance_depth + depth + 1,
|
|
|| component.constructor.clone(),
|
|
);
|
|
};
|
|
}
|
|
}
|
|
}
|
|
|
|
Ok(())
|
|
}
|
|
|
|
/// Registers the components inherited from `required` for the given `requiree`,
|
|
/// returning the requirements in a list.
|
|
///
|
|
/// # Safety
|
|
///
|
|
/// The given component IDs `requiree` and `required` must be valid.
|
|
unsafe fn register_inherited_required_components(
|
|
&mut self,
|
|
requiree: ComponentId,
|
|
required: ComponentId,
|
|
required_components: &mut RequiredComponents,
|
|
) -> Vec<(ComponentId, RequiredComponent)> {
|
|
// Get required components inherited from the `required` component.
|
|
// SAFETY: The caller ensures that the `required` component is valid.
|
|
let required_component_info = unsafe { self.get_info(required).debug_checked_unwrap() };
|
|
let inherited_requirements: Vec<(ComponentId, RequiredComponent)> = required_component_info
|
|
.required_components()
|
|
.0
|
|
.iter()
|
|
.map(|(component_id, required_component)| {
|
|
(
|
|
*component_id,
|
|
RequiredComponent {
|
|
constructor: required_component.constructor.clone(),
|
|
// Add `1` to the inheritance depth since this will be registered
|
|
// for the component that requires `required`.
|
|
inheritance_depth: required_component.inheritance_depth + 1,
|
|
},
|
|
)
|
|
})
|
|
.collect();
|
|
|
|
// Register the new required components.
|
|
for (component_id, component) in inherited_requirements.iter() {
|
|
// Register the required component for the requiree.
|
|
// SAFETY: Component ID and constructor match the ones on the original requiree.
|
|
unsafe {
|
|
required_components.register_dynamic_with(
|
|
*component_id,
|
|
component.inheritance_depth,
|
|
|| component.constructor.clone(),
|
|
);
|
|
};
|
|
|
|
// Add the requiree to the list of components that require the required component.
|
|
// SAFETY: The caller ensures that the required components are valid.
|
|
let required_by = unsafe {
|
|
self.get_required_by_mut(*component_id)
|
|
.debug_checked_unwrap()
|
|
};
|
|
required_by.insert(requiree);
|
|
}
|
|
|
|
inherited_requirements
|
|
}
|
|
|
|
/// Registers the given component `R` and [required components] inherited from it as required by `T`,
|
|
/// and adds `T` to their lists of requirees.
|
|
///
|
|
/// The given `inheritance_depth` determines how many levels of inheritance deep the requirement is.
|
|
/// A direct requirement has a depth of `0`, and each level of inheritance increases the depth by `1`.
|
|
/// Lower depths are more specific requirements, and can override existing less specific registrations.
|
|
///
|
|
/// This method does *not* register any components as required by components that require `T`.
|
|
///
|
|
/// [required component]: Component#required-components
|
|
///
|
|
/// # Safety
|
|
///
|
|
/// The given component IDs `required` and `requiree` must be valid.
|
|
pub(crate) unsafe fn register_required_components_manual_unchecked<R: Component>(
|
|
&mut self,
|
|
requiree: ComponentId,
|
|
required: ComponentId,
|
|
required_components: &mut RequiredComponents,
|
|
constructor: fn() -> R,
|
|
inheritance_depth: u16,
|
|
) {
|
|
// Components cannot require themselves.
|
|
if required == requiree {
|
|
return;
|
|
}
|
|
|
|
// Register the required component `R` for the requiree.
|
|
required_components.register_by_id(required, constructor, inheritance_depth);
|
|
|
|
// Add the requiree to the list of components that require `R`.
|
|
// SAFETY: The caller ensures that the component ID is valid.
|
|
// Assuming it is valid, the component is in the list of required components, so it must exist already.
|
|
let required_by = unsafe { self.get_required_by_mut(required).debug_checked_unwrap() };
|
|
required_by.insert(requiree);
|
|
|
|
self.register_inherited_required_components(requiree, required, required_components);
|
|
}
|
|
|
|
#[inline]
|
|
pub(crate) fn get_required_by(&self, id: ComponentId) -> Option<&HashSet<ComponentId>> {
|
|
self.components
|
|
.get(id.0)
|
|
.and_then(|info| info.as_ref().map(|info| &info.required_by))
|
|
}
|
|
|
|
#[inline]
|
|
pub(crate) fn get_required_by_mut(
|
|
&mut self,
|
|
id: ComponentId,
|
|
) -> Option<&mut HashSet<ComponentId>> {
|
|
self.components
|
|
.get_mut(id.0)
|
|
.and_then(|info| info.as_mut().map(|info| &mut info.required_by))
|
|
}
|
|
|
|
/// Returns true if the [`ComponentId`] is fully registered and valid.
|
|
/// Ids may be invalid if they are still queued to be registered.
|
|
/// Those ids are still correct, but they are not usable in every context yet.
|
|
#[inline]
|
|
pub fn is_id_valid(&self, id: ComponentId) -> bool {
|
|
self.components.get(id.0).is_some_and(Option::is_some)
|
|
}
|
|
|
|
/// Type-erased equivalent of [`Components::valid_component_id()`].
|
|
#[inline]
|
|
pub fn get_valid_id(&self, type_id: TypeId) -> Option<ComponentId> {
|
|
self.indices.get(&type_id).copied()
|
|
}
|
|
|
|
/// Returns the [`ComponentId`] of the given [`Component`] type `T` if it is fully registered.
|
|
/// If you want to include queued registration, see [`Components::component_id()`].
|
|
///
|
|
/// ```
|
|
/// use bevy_ecs::prelude::*;
|
|
///
|
|
/// let mut world = World::new();
|
|
///
|
|
/// #[derive(Component)]
|
|
/// struct ComponentA;
|
|
///
|
|
/// let component_a_id = world.register_component::<ComponentA>();
|
|
///
|
|
/// assert_eq!(component_a_id, world.components().valid_component_id::<ComponentA>().unwrap())
|
|
/// ```
|
|
///
|
|
/// # See also
|
|
///
|
|
/// * [`Components::get_valid_id()`]
|
|
/// * [`Components::valid_resource_id()`]
|
|
/// * [`World::component_id()`]
|
|
#[inline]
|
|
pub fn valid_component_id<T: Component>(&self) -> Option<ComponentId> {
|
|
self.get_valid_id(TypeId::of::<T>())
|
|
}
|
|
|
|
/// Type-erased equivalent of [`Components::valid_resource_id()`].
|
|
#[inline]
|
|
pub fn get_valid_resource_id(&self, type_id: TypeId) -> Option<ComponentId> {
|
|
self.resource_indices.get(&type_id).copied()
|
|
}
|
|
|
|
/// Returns the [`ComponentId`] of the given [`Resource`] type `T` if it is fully registered.
|
|
/// If you want to include queued registration, see [`Components::resource_id()`].
|
|
///
|
|
/// ```
|
|
/// use bevy_ecs::prelude::*;
|
|
///
|
|
/// let mut world = World::new();
|
|
///
|
|
/// #[derive(Resource, Default)]
|
|
/// struct ResourceA;
|
|
///
|
|
/// let resource_a_id = world.init_resource::<ResourceA>();
|
|
///
|
|
/// assert_eq!(resource_a_id, world.components().valid_resource_id::<ResourceA>().unwrap())
|
|
/// ```
|
|
///
|
|
/// # See also
|
|
///
|
|
/// * [`Components::valid_component_id()`]
|
|
/// * [`Components::get_resource_id()`]
|
|
#[inline]
|
|
pub fn valid_resource_id<T: Resource>(&self) -> Option<ComponentId> {
|
|
self.get_valid_resource_id(TypeId::of::<T>())
|
|
}
|
|
|
|
/// Type-erased equivalent of [`Components::component_id()`].
|
|
#[inline]
|
|
pub fn get_id(&self, type_id: TypeId) -> Option<ComponentId> {
|
|
self.indices.get(&type_id).copied().or_else(|| {
|
|
self.queued
|
|
.read()
|
|
.unwrap_or_else(PoisonError::into_inner)
|
|
.components
|
|
.get(&type_id)
|
|
.map(|queued| queued.id)
|
|
})
|
|
}
|
|
|
|
/// Returns the [`ComponentId`] of the given [`Component`] type `T`.
|
|
///
|
|
/// The returned `ComponentId` is specific to the `Components` instance
|
|
/// it was retrieved from and should not be used with another `Components`
|
|
/// instance.
|
|
///
|
|
/// Returns [`None`] if the `Component` type has not
|
|
/// yet been initialized using [`ComponentsRegistrator::register_component()`] or [`ComponentsQueuedRegistrator::queue_register_component()`].
|
|
///
|
|
/// ```
|
|
/// use bevy_ecs::prelude::*;
|
|
///
|
|
/// let mut world = World::new();
|
|
///
|
|
/// #[derive(Component)]
|
|
/// struct ComponentA;
|
|
///
|
|
/// let component_a_id = world.register_component::<ComponentA>();
|
|
///
|
|
/// assert_eq!(component_a_id, world.components().component_id::<ComponentA>().unwrap())
|
|
/// ```
|
|
///
|
|
/// # See also
|
|
///
|
|
/// * [`Components::get_id()`]
|
|
/// * [`Components::resource_id()`]
|
|
/// * [`World::component_id()`]
|
|
#[inline]
|
|
pub fn component_id<T: Component>(&self) -> Option<ComponentId> {
|
|
self.get_id(TypeId::of::<T>())
|
|
}
|
|
|
|
/// Type-erased equivalent of [`Components::resource_id()`].
|
|
#[inline]
|
|
pub fn get_resource_id(&self, type_id: TypeId) -> Option<ComponentId> {
|
|
self.resource_indices.get(&type_id).copied().or_else(|| {
|
|
self.queued
|
|
.read()
|
|
.unwrap_or_else(PoisonError::into_inner)
|
|
.resources
|
|
.get(&type_id)
|
|
.map(|queued| queued.id)
|
|
})
|
|
}
|
|
|
|
/// Returns the [`ComponentId`] of the given [`Resource`] type `T`.
|
|
///
|
|
/// The returned `ComponentId` is specific to the `Components` instance
|
|
/// it was retrieved from and should not be used with another `Components`
|
|
/// instance.
|
|
///
|
|
/// Returns [`None`] if the `Resource` type has not
|
|
/// yet been initialized using [`ComponentsRegistrator::register_resource()`] or [`ComponentsQueuedRegistrator::queue_register_resource()`].
|
|
///
|
|
/// ```
|
|
/// use bevy_ecs::prelude::*;
|
|
///
|
|
/// let mut world = World::new();
|
|
///
|
|
/// #[derive(Resource, Default)]
|
|
/// struct ResourceA;
|
|
///
|
|
/// let resource_a_id = world.init_resource::<ResourceA>();
|
|
///
|
|
/// assert_eq!(resource_a_id, world.components().resource_id::<ResourceA>().unwrap())
|
|
/// ```
|
|
///
|
|
/// # See also
|
|
///
|
|
/// * [`Components::component_id()`]
|
|
/// * [`Components::get_resource_id()`]
|
|
#[inline]
|
|
pub fn resource_id<T: Resource>(&self) -> Option<ComponentId> {
|
|
self.get_resource_id(TypeId::of::<T>())
|
|
}
|
|
|
|
/// # Safety
|
|
///
|
|
/// The [`ComponentDescriptor`] must match the [`TypeId`].
|
|
/// The [`ComponentId`] must be unique.
|
|
/// The [`TypeId`] and [`ComponentId`] must not be registered or queued.
|
|
#[inline]
|
|
unsafe fn register_resource_unchecked(
|
|
&mut self,
|
|
type_id: TypeId,
|
|
component_id: ComponentId,
|
|
descriptor: ComponentDescriptor,
|
|
) {
|
|
// SAFETY: ensured by caller
|
|
unsafe {
|
|
self.register_component_inner(component_id, descriptor);
|
|
}
|
|
let prev = self.resource_indices.insert(type_id, component_id);
|
|
debug_assert!(prev.is_none());
|
|
}
|
|
|
|
/// Gets an iterator over all components fully registered with this instance.
|
|
pub fn iter_registered(&self) -> impl Iterator<Item = &ComponentInfo> + '_ {
|
|
self.components.iter().filter_map(Option::as_ref)
|
|
}
|
|
}
|
|
|
|
/// A value that tracks when a system ran relative to other systems.
|
|
/// This is used to power change detection.
|
|
///
|
|
/// *Note* that a system that hasn't been run yet has a `Tick` of 0.
|
|
#[derive(Copy, Clone, Default, Debug, Eq, Hash, PartialEq)]
|
|
#[cfg_attr(
|
|
feature = "bevy_reflect",
|
|
derive(Reflect),
|
|
reflect(Debug, Hash, PartialEq, Clone)
|
|
)]
|
|
pub struct Tick {
|
|
tick: u32,
|
|
}
|
|
|
|
impl Tick {
|
|
/// The maximum relative age for a change tick.
|
|
/// The value of this is equal to [`MAX_CHANGE_AGE`].
|
|
///
|
|
/// Since change detection will not work for any ticks older than this,
|
|
/// ticks are periodically scanned to ensure their relative values are below this.
|
|
pub const MAX: Self = Self::new(MAX_CHANGE_AGE);
|
|
|
|
/// Creates a new [`Tick`] wrapping the given value.
|
|
#[inline]
|
|
pub const fn new(tick: u32) -> Self {
|
|
Self { tick }
|
|
}
|
|
|
|
/// Gets the value of this change tick.
|
|
#[inline]
|
|
pub const fn get(self) -> u32 {
|
|
self.tick
|
|
}
|
|
|
|
/// Sets the value of this change tick.
|
|
#[inline]
|
|
pub fn set(&mut self, tick: u32) {
|
|
self.tick = tick;
|
|
}
|
|
|
|
/// Returns `true` if this `Tick` occurred since the system's `last_run`.
|
|
///
|
|
/// `this_run` is the current tick of the system, used as a reference to help deal with wraparound.
|
|
#[inline]
|
|
pub fn is_newer_than(self, last_run: Tick, this_run: Tick) -> bool {
|
|
// This works even with wraparound because the world tick (`this_run`) is always "newer" than
|
|
// `last_run` and `self.tick`, and we scan periodically to clamp `ComponentTicks` values
|
|
// so they never get older than `u32::MAX` (the difference would overflow).
|
|
//
|
|
// The clamp here ensures determinism (since scans could differ between app runs).
|
|
let ticks_since_insert = this_run.relative_to(self).tick.min(MAX_CHANGE_AGE);
|
|
let ticks_since_system = this_run.relative_to(last_run).tick.min(MAX_CHANGE_AGE);
|
|
|
|
ticks_since_system > ticks_since_insert
|
|
}
|
|
|
|
/// Returns a change tick representing the relationship between `self` and `other`.
|
|
#[inline]
|
|
pub(crate) fn relative_to(self, other: Self) -> Self {
|
|
let tick = self.tick.wrapping_sub(other.tick);
|
|
Self { tick }
|
|
}
|
|
|
|
/// Wraps this change tick's value if it exceeds [`Tick::MAX`].
|
|
///
|
|
/// Returns `true` if wrapping was performed. Otherwise, returns `false`.
|
|
#[inline]
|
|
pub fn check_tick(&mut self, check: CheckChangeTicks) -> bool {
|
|
let age = check.present_tick().relative_to(*self);
|
|
// This comparison assumes that `age` has not overflowed `u32::MAX` before, which will be true
|
|
// so long as this check always runs before that can happen.
|
|
if age.get() > Self::MAX.get() {
|
|
*self = check.present_tick().relative_to(Self::MAX);
|
|
true
|
|
} else {
|
|
false
|
|
}
|
|
}
|
|
}
|
|
|
|
/// An observer [`Event`] that can be used to maintain [`Tick`]s in custom data structures, enabling to make
|
|
/// use of bevy's periodic checks that clamps ticks to a certain range, preventing overflows and thus
|
|
/// keeping methods like [`Tick::is_newer_than`] reliably return `false` for ticks that got too old.
|
|
///
|
|
/// # Example
|
|
///
|
|
/// Here a schedule is stored in a custom resource. This way the systems in it would not have their change
|
|
/// ticks automatically updated via [`World::check_change_ticks`], possibly causing `Tick`-related bugs on
|
|
/// long-running apps.
|
|
///
|
|
/// To fix that, add an observer for this event that calls the schedule's
|
|
/// [`Schedule::check_change_ticks`](bevy_ecs::schedule::Schedule::check_change_ticks).
|
|
///
|
|
/// ```
|
|
/// use bevy_ecs::prelude::*;
|
|
/// use bevy_ecs::component::CheckChangeTicks;
|
|
///
|
|
/// #[derive(Resource)]
|
|
/// struct CustomSchedule(Schedule);
|
|
///
|
|
/// # let mut world = World::new();
|
|
/// world.add_observer(|check: On<CheckChangeTicks>, mut schedule: ResMut<CustomSchedule>| {
|
|
/// schedule.0.check_change_ticks(*check);
|
|
/// });
|
|
/// ```
|
|
#[derive(Debug, Clone, Copy, Event)]
|
|
pub struct CheckChangeTicks(pub(crate) Tick);
|
|
|
|
impl CheckChangeTicks {
|
|
/// Get the present `Tick` that other ticks get compared to.
|
|
pub fn present_tick(self) -> Tick {
|
|
self.0
|
|
}
|
|
}
|
|
|
|
/// Interior-mutable access to the [`Tick`]s for a single component or resource.
|
|
#[derive(Copy, Clone, Debug)]
|
|
pub struct TickCells<'a> {
|
|
/// The tick indicating when the value was added to the world.
|
|
pub added: &'a UnsafeCell<Tick>,
|
|
/// The tick indicating the last time the value was modified.
|
|
pub changed: &'a UnsafeCell<Tick>,
|
|
}
|
|
|
|
impl<'a> TickCells<'a> {
|
|
/// # Safety
|
|
/// All cells contained within must uphold the safety invariants of [`UnsafeCellDeref::read`].
|
|
#[inline]
|
|
pub(crate) unsafe fn read(&self) -> ComponentTicks {
|
|
ComponentTicks {
|
|
// SAFETY: The callers uphold the invariants for `read`.
|
|
added: unsafe { self.added.read() },
|
|
// SAFETY: The callers uphold the invariants for `read`.
|
|
changed: unsafe { self.changed.read() },
|
|
}
|
|
}
|
|
}
|
|
|
|
/// Records when a component or resource was added and when it was last mutably dereferenced (or added).
|
|
#[derive(Copy, Clone, Debug)]
|
|
#[cfg_attr(feature = "bevy_reflect", derive(Reflect), reflect(Debug, Clone))]
|
|
pub struct ComponentTicks {
|
|
/// Tick recording the time this component or resource was added.
|
|
pub added: Tick,
|
|
|
|
/// Tick recording the time this component or resource was most recently changed.
|
|
pub changed: Tick,
|
|
}
|
|
|
|
impl ComponentTicks {
|
|
/// Returns `true` if the component or resource was added after the system last ran
|
|
/// (or the system is running for the first time).
|
|
#[inline]
|
|
pub fn is_added(&self, last_run: Tick, this_run: Tick) -> bool {
|
|
self.added.is_newer_than(last_run, this_run)
|
|
}
|
|
|
|
/// Returns `true` if the component or resource was added or mutably dereferenced after the system last ran
|
|
/// (or the system is running for the first time).
|
|
#[inline]
|
|
pub fn is_changed(&self, last_run: Tick, this_run: Tick) -> bool {
|
|
self.changed.is_newer_than(last_run, this_run)
|
|
}
|
|
|
|
/// Creates a new instance with the same change tick for `added` and `changed`.
|
|
pub fn new(change_tick: Tick) -> Self {
|
|
Self {
|
|
added: change_tick,
|
|
changed: change_tick,
|
|
}
|
|
}
|
|
|
|
/// Manually sets the change tick.
|
|
///
|
|
/// This is normally done automatically via the [`DerefMut`] implementation
|
|
/// on [`Mut<T>`](crate::change_detection::Mut), [`ResMut<T>`](crate::change_detection::ResMut), etc.
|
|
/// However, components and resources that make use of interior mutability might require manual updates.
|
|
///
|
|
/// # Example
|
|
/// ```no_run
|
|
/// # use bevy_ecs::{world::World, component::ComponentTicks};
|
|
/// let world: World = unimplemented!();
|
|
/// let component_ticks: ComponentTicks = unimplemented!();
|
|
///
|
|
/// component_ticks.set_changed(world.read_change_tick());
|
|
/// ```
|
|
#[inline]
|
|
pub fn set_changed(&mut self, change_tick: Tick) {
|
|
self.changed = change_tick;
|
|
}
|
|
}
|
|
|
|
/// A [`SystemParam`] that provides access to the [`ComponentId`] for a specific component type.
|
|
///
|
|
/// # Example
|
|
/// ```
|
|
/// # use bevy_ecs::{system::Local, component::{Component, ComponentId, ComponentIdFor}};
|
|
/// #[derive(Component)]
|
|
/// struct Player;
|
|
/// fn my_system(component_id: ComponentIdFor<Player>) {
|
|
/// let component_id: ComponentId = component_id.get();
|
|
/// // ...
|
|
/// }
|
|
/// ```
|
|
#[derive(SystemParam)]
|
|
pub struct ComponentIdFor<'s, T: Component>(Local<'s, InitComponentId<T>>);
|
|
|
|
impl<T: Component> ComponentIdFor<'_, T> {
|
|
/// Gets the [`ComponentId`] for the type `T`.
|
|
#[inline]
|
|
pub fn get(&self) -> ComponentId {
|
|
**self
|
|
}
|
|
}
|
|
|
|
impl<T: Component> Deref for ComponentIdFor<'_, T> {
|
|
type Target = ComponentId;
|
|
fn deref(&self) -> &Self::Target {
|
|
&self.0.component_id
|
|
}
|
|
}
|
|
|
|
impl<T: Component> From<ComponentIdFor<'_, T>> for ComponentId {
|
|
#[inline]
|
|
fn from(to_component_id: ComponentIdFor<T>) -> ComponentId {
|
|
*to_component_id
|
|
}
|
|
}
|
|
|
|
/// Initializes the [`ComponentId`] for a specific type when used with [`FromWorld`].
|
|
struct InitComponentId<T: Component> {
|
|
component_id: ComponentId,
|
|
marker: PhantomData<T>,
|
|
}
|
|
|
|
impl<T: Component> FromWorld for InitComponentId<T> {
|
|
fn from_world(world: &mut World) -> Self {
|
|
Self {
|
|
component_id: world.register_component::<T>(),
|
|
marker: PhantomData,
|
|
}
|
|
}
|
|
}
|
|
|
|
/// An error returned when the registration of a required component fails.
|
|
#[derive(Error, Debug)]
|
|
#[non_exhaustive]
|
|
pub enum RequiredComponentsError {
|
|
/// The component is already a directly required component for the requiree.
|
|
#[error("Component {0:?} already directly requires component {1:?}")]
|
|
DuplicateRegistration(ComponentId, ComponentId),
|
|
/// An archetype with the component that requires other components already exists
|
|
#[error("An archetype with the component {0:?} that requires other components already exists")]
|
|
ArchetypeExists(ComponentId),
|
|
}
|
|
|
|
/// A Required Component constructor. See [`Component`] for details.
|
|
#[derive(Clone)]
|
|
pub struct RequiredComponentConstructor(
|
|
pub Arc<dyn Fn(&mut Table, &mut SparseSets, Tick, TableRow, Entity, MaybeLocation)>,
|
|
);
|
|
|
|
impl RequiredComponentConstructor {
|
|
/// # Safety
|
|
/// This is intended to only be called in the context of [`BundleInfo::write_components`] to initialized required components.
|
|
/// Calling it _anywhere else_ should be considered unsafe.
|
|
///
|
|
/// `table_row` and `entity` must correspond to a valid entity that currently needs a component initialized via the constructor stored
|
|
/// on this [`RequiredComponentConstructor`]. The stored constructor must correspond to a component on `entity` that needs initialization.
|
|
/// `table` and `sparse_sets` must correspond to storages on a world where `entity` needs this required component initialized.
|
|
///
|
|
/// Again, don't call this anywhere but [`BundleInfo::write_components`].
|
|
pub(crate) unsafe fn initialize(
|
|
&self,
|
|
table: &mut Table,
|
|
sparse_sets: &mut SparseSets,
|
|
change_tick: Tick,
|
|
table_row: TableRow,
|
|
entity: Entity,
|
|
caller: MaybeLocation,
|
|
) {
|
|
(self.0)(table, sparse_sets, change_tick, table_row, entity, caller);
|
|
}
|
|
}
|
|
|
|
/// Metadata associated with a required component. See [`Component`] for details.
|
|
#[derive(Clone)]
|
|
pub struct RequiredComponent {
|
|
/// The constructor used for the required component.
|
|
pub constructor: RequiredComponentConstructor,
|
|
|
|
/// The depth of the component requirement in the requirement hierarchy for this component.
|
|
/// This is used for determining which constructor is used in cases where there are duplicate requires.
|
|
///
|
|
/// For example, consider the inheritance tree `X -> Y -> Z`, where `->` indicates a requirement.
|
|
/// `X -> Y` and `Y -> Z` are direct requirements with a depth of 0, while `Z` is only indirectly
|
|
/// required for `X` with a depth of `1`.
|
|
///
|
|
/// In cases where there are multiple conflicting requirements with the same depth, a higher priority
|
|
/// will be given to components listed earlier in the `require` attribute, or to the latest added requirement
|
|
/// if registered at runtime.
|
|
pub inheritance_depth: u16,
|
|
}
|
|
|
|
/// The collection of metadata for components that are required for a given component.
|
|
///
|
|
/// For more information, see the "Required Components" section of [`Component`].
|
|
#[derive(Default, Clone)]
|
|
pub struct RequiredComponents(pub(crate) HashMap<ComponentId, RequiredComponent>);
|
|
|
|
impl Debug for RequiredComponents {
|
|
fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
|
|
f.debug_tuple("RequiredComponents")
|
|
.field(&self.0.keys())
|
|
.finish()
|
|
}
|
|
}
|
|
|
|
impl RequiredComponents {
|
|
/// Registers a required component.
|
|
///
|
|
/// If the component is already registered, it will be overwritten if the given inheritance depth
|
|
/// is smaller than the depth of the existing registration. Otherwise, the new registration will be ignored.
|
|
///
|
|
/// # Safety
|
|
///
|
|
/// `component_id` must match the type initialized by `constructor`.
|
|
/// `constructor` _must_ initialize a component for `component_id` in such a way that
|
|
/// matches the storage type of the component. It must only use the given `table_row` or `Entity` to
|
|
/// initialize the storage for `component_id` corresponding to the given entity.
|
|
pub unsafe fn register_dynamic_with(
|
|
&mut self,
|
|
component_id: ComponentId,
|
|
inheritance_depth: u16,
|
|
constructor: impl FnOnce() -> RequiredComponentConstructor,
|
|
) {
|
|
let entry = self.0.entry(component_id);
|
|
match entry {
|
|
bevy_platform::collections::hash_map::Entry::Occupied(mut occupied) => {
|
|
let current = occupied.get_mut();
|
|
if current.inheritance_depth > inheritance_depth {
|
|
*current = RequiredComponent {
|
|
constructor: constructor(),
|
|
inheritance_depth,
|
|
}
|
|
}
|
|
}
|
|
bevy_platform::collections::hash_map::Entry::Vacant(vacant) => {
|
|
vacant.insert(RequiredComponent {
|
|
constructor: constructor(),
|
|
inheritance_depth,
|
|
});
|
|
}
|
|
}
|
|
}
|
|
|
|
/// Registers a required component.
|
|
///
|
|
/// If the component is already registered, it will be overwritten if the given inheritance depth
|
|
/// is smaller than the depth of the existing registration. Otherwise, the new registration will be ignored.
|
|
pub fn register<C: Component>(
|
|
&mut self,
|
|
components: &mut ComponentsRegistrator,
|
|
constructor: fn() -> C,
|
|
inheritance_depth: u16,
|
|
) {
|
|
let component_id = components.register_component::<C>();
|
|
self.register_by_id(component_id, constructor, inheritance_depth);
|
|
}
|
|
|
|
/// Registers the [`Component`] with the given ID as required if it exists.
|
|
///
|
|
/// If the component is already registered, it will be overwritten if the given inheritance depth
|
|
/// is smaller than the depth of the existing registration. Otherwise, the new registration will be ignored.
|
|
pub fn register_by_id<C: Component>(
|
|
&mut self,
|
|
component_id: ComponentId,
|
|
constructor: fn() -> C,
|
|
inheritance_depth: u16,
|
|
) {
|
|
let erased = || {
|
|
RequiredComponentConstructor({
|
|
// `portable-atomic-util` `Arc` is not able to coerce an unsized
|
|
// type like `std::sync::Arc` can. Creating a `Box` first does the
|
|
// coercion.
|
|
//
|
|
// This would be resolved by https://github.com/rust-lang/rust/issues/123430
|
|
|
|
#[cfg(not(target_has_atomic = "ptr"))]
|
|
use alloc::boxed::Box;
|
|
|
|
type Constructor = dyn for<'a, 'b> Fn(
|
|
&'a mut Table,
|
|
&'b mut SparseSets,
|
|
Tick,
|
|
TableRow,
|
|
Entity,
|
|
MaybeLocation,
|
|
);
|
|
|
|
#[cfg(not(target_has_atomic = "ptr"))]
|
|
type Intermediate<T> = Box<T>;
|
|
|
|
#[cfg(target_has_atomic = "ptr")]
|
|
type Intermediate<T> = Arc<T>;
|
|
|
|
let boxed: Intermediate<Constructor> = Intermediate::new(
|
|
move |table, sparse_sets, change_tick, table_row, entity, caller| {
|
|
OwningPtr::make(constructor(), |ptr| {
|
|
// SAFETY: This will only be called in the context of `BundleInfo::write_components`, which will
|
|
// pass in a valid table_row and entity requiring a C constructor
|
|
// C::STORAGE_TYPE is the storage type associated with `component_id` / `C`
|
|
// `ptr` points to valid `C` data, which matches the type associated with `component_id`
|
|
unsafe {
|
|
BundleInfo::initialize_required_component(
|
|
table,
|
|
sparse_sets,
|
|
change_tick,
|
|
table_row,
|
|
entity,
|
|
component_id,
|
|
C::STORAGE_TYPE,
|
|
ptr,
|
|
caller,
|
|
);
|
|
}
|
|
});
|
|
},
|
|
);
|
|
|
|
Arc::from(boxed)
|
|
})
|
|
};
|
|
|
|
// SAFETY:
|
|
// `component_id` matches the type initialized by the `erased` constructor above.
|
|
// `erased` initializes a component for `component_id` in such a way that
|
|
// matches the storage type of the component. It only uses the given `table_row` or `Entity` to
|
|
// initialize the storage corresponding to the given entity.
|
|
unsafe { self.register_dynamic_with(component_id, inheritance_depth, erased) };
|
|
}
|
|
|
|
/// Iterates the ids of all required components. This includes recursive required components.
|
|
pub fn iter_ids(&self) -> impl Iterator<Item = ComponentId> + '_ {
|
|
self.0.keys().copied()
|
|
}
|
|
|
|
/// Removes components that are explicitly provided in a given [`Bundle`]. These components should
|
|
/// be logically treated as normal components, not "required components".
|
|
///
|
|
/// [`Bundle`]: crate::bundle::Bundle
|
|
pub(crate) fn remove_explicit_components(&mut self, components: &[ComponentId]) {
|
|
for component in components {
|
|
self.0.remove(component);
|
|
}
|
|
}
|
|
|
|
/// Merges `required_components` into this collection. This only inserts a required component
|
|
/// if it _did not already exist_ *or* if the required component is more specific than the existing one
|
|
/// (in other words, if the inheritance depth is smaller).
|
|
///
|
|
/// See [`register_dynamic_with`](Self::register_dynamic_with) for details.
|
|
pub(crate) fn merge(&mut self, required_components: &RequiredComponents) {
|
|
for (
|
|
component_id,
|
|
RequiredComponent {
|
|
constructor,
|
|
inheritance_depth,
|
|
},
|
|
) in required_components.0.iter()
|
|
{
|
|
// SAFETY: This exact registration must have been done on `required_components`, so safety is ensured by that caller.
|
|
unsafe {
|
|
self.register_dynamic_with(*component_id, *inheritance_depth, || {
|
|
constructor.clone()
|
|
});
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
// NOTE: This should maybe be private, but it is currently public so that `bevy_ecs_macros` can use it.
|
|
// This exists as a standalone function instead of being inlined into the component derive macro so as
|
|
// to reduce the amount of generated code.
|
|
#[doc(hidden)]
|
|
pub fn enforce_no_required_components_recursion(
|
|
components: &Components,
|
|
recursion_check_stack: &[ComponentId],
|
|
) {
|
|
if let Some((&requiree, check)) = recursion_check_stack.split_last() {
|
|
if let Some(direct_recursion) = check
|
|
.iter()
|
|
.position(|&id| id == requiree)
|
|
.map(|index| index == check.len() - 1)
|
|
{
|
|
panic!(
|
|
"Recursive required components detected: {}\nhelp: {}",
|
|
recursion_check_stack
|
|
.iter()
|
|
.map(|id| format!("{}", components.get_name(*id).unwrap().shortname()))
|
|
.collect::<Vec<_>>()
|
|
.join(" → "),
|
|
if direct_recursion {
|
|
format!(
|
|
"Remove require({}).",
|
|
components.get_name(requiree).unwrap().shortname()
|
|
)
|
|
} else {
|
|
"If this is intentional, consider merging the components.".into()
|
|
}
|
|
);
|
|
}
|
|
}
|
|
}
|
|
|
|
/// Component [clone handler function](ComponentCloneFn) implemented using the [`Clone`] trait.
|
|
/// Can be [set](Component::clone_behavior) as clone handler for the specific component it is implemented for.
|
|
/// It will panic if set as handler for any other component.
|
|
///
|
|
pub fn component_clone_via_clone<C: Clone + Component>(
|
|
source: &SourceComponent,
|
|
ctx: &mut ComponentCloneCtx,
|
|
) {
|
|
if let Some(component) = source.read::<C>() {
|
|
ctx.write_target_component(component.clone());
|
|
}
|
|
}
|
|
|
|
/// Component [clone handler function](ComponentCloneFn) implemented using reflect.
|
|
/// Can be [set](Component::clone_behavior) as clone handler for any registered component,
|
|
/// but only reflected components will be cloned.
|
|
///
|
|
/// To clone a component using this handler, the following must be true:
|
|
/// - World has [`AppTypeRegistry`](crate::reflect::AppTypeRegistry)
|
|
/// - Component has [`TypeId`]
|
|
/// - Component is registered
|
|
/// - Component has [`ReflectFromPtr`](bevy_reflect::ReflectFromPtr) registered
|
|
/// - Component can be cloned via [`PartialReflect::reflect_clone`] _or_ has one of the following registered: [`ReflectFromReflect`](bevy_reflect::ReflectFromReflect),
|
|
/// [`ReflectDefault`](bevy_reflect::std_traits::ReflectDefault), [`ReflectFromWorld`](crate::reflect::ReflectFromWorld)
|
|
///
|
|
/// If any of the conditions is not satisfied, the component will be skipped.
|
|
///
|
|
/// See [`EntityClonerBuilder`](crate::entity::EntityClonerBuilder) for details.
|
|
///
|
|
/// [`PartialReflect::reflect_clone`]: bevy_reflect::PartialReflect::reflect_clone
|
|
#[cfg(feature = "bevy_reflect")]
|
|
pub fn component_clone_via_reflect(source: &SourceComponent, ctx: &mut ComponentCloneCtx) {
|
|
let Some(app_registry) = ctx.type_registry().cloned() else {
|
|
return;
|
|
};
|
|
let registry = app_registry.read();
|
|
let Some(source_component_reflect) = source.read_reflect(®istry) else {
|
|
return;
|
|
};
|
|
let component_info = ctx.component_info();
|
|
// checked in read_source_component_reflect
|
|
let type_id = component_info.type_id().unwrap();
|
|
|
|
// Try to clone using `reflect_clone`
|
|
if let Ok(mut component) = source_component_reflect.reflect_clone() {
|
|
if let Some(reflect_component) =
|
|
registry.get_type_data::<crate::reflect::ReflectComponent>(type_id)
|
|
{
|
|
reflect_component.map_entities(&mut *component, ctx.entity_mapper());
|
|
}
|
|
drop(registry);
|
|
|
|
ctx.write_target_component_reflect(component);
|
|
return;
|
|
}
|
|
|
|
// Try to clone using ReflectFromReflect
|
|
if let Some(reflect_from_reflect) =
|
|
registry.get_type_data::<bevy_reflect::ReflectFromReflect>(type_id)
|
|
{
|
|
if let Some(mut component) =
|
|
reflect_from_reflect.from_reflect(source_component_reflect.as_partial_reflect())
|
|
{
|
|
if let Some(reflect_component) =
|
|
registry.get_type_data::<crate::reflect::ReflectComponent>(type_id)
|
|
{
|
|
reflect_component.map_entities(&mut *component, ctx.entity_mapper());
|
|
}
|
|
drop(registry);
|
|
|
|
ctx.write_target_component_reflect(component);
|
|
return;
|
|
}
|
|
}
|
|
// Else, try to clone using ReflectDefault
|
|
if let Some(reflect_default) =
|
|
registry.get_type_data::<bevy_reflect::std_traits::ReflectDefault>(type_id)
|
|
{
|
|
let mut component = reflect_default.default();
|
|
component.apply(source_component_reflect.as_partial_reflect());
|
|
drop(registry);
|
|
ctx.write_target_component_reflect(component);
|
|
return;
|
|
}
|
|
// Otherwise, try to clone using ReflectFromWorld
|
|
if let Some(reflect_from_world) =
|
|
registry.get_type_data::<crate::reflect::ReflectFromWorld>(type_id)
|
|
{
|
|
let reflect_from_world = reflect_from_world.clone();
|
|
let source_component_cloned = source_component_reflect.to_dynamic();
|
|
let component_layout = component_info.layout();
|
|
let target = ctx.target();
|
|
let component_id = ctx.component_id();
|
|
drop(registry);
|
|
ctx.queue_deferred(move |world: &mut World, mapper: &mut dyn EntityMapper| {
|
|
let mut component = reflect_from_world.from_world(world);
|
|
assert_eq!(type_id, (*component).type_id());
|
|
component.apply(source_component_cloned.as_partial_reflect());
|
|
if let Some(reflect_component) = app_registry
|
|
.read()
|
|
.get_type_data::<crate::reflect::ReflectComponent>(type_id)
|
|
{
|
|
reflect_component.map_entities(&mut *component, mapper);
|
|
}
|
|
// SAFETY:
|
|
// - component_id is from the same world as target entity
|
|
// - component is a valid value represented by component_id
|
|
unsafe {
|
|
let raw_component_ptr =
|
|
core::ptr::NonNull::new_unchecked(Box::into_raw(component).cast::<u8>());
|
|
world
|
|
.entity_mut(target)
|
|
.insert_by_id(component_id, OwningPtr::new(raw_component_ptr));
|
|
|
|
if component_layout.size() > 0 {
|
|
// Ensure we don't attempt to deallocate zero-sized components
|
|
alloc::alloc::dealloc(raw_component_ptr.as_ptr(), component_layout);
|
|
}
|
|
}
|
|
});
|
|
}
|
|
}
|
|
|
|
/// Noop implementation of component clone handler function.
|
|
///
|
|
/// See [`EntityClonerBuilder`](crate::entity::EntityClonerBuilder) for details.
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pub fn component_clone_ignore(_source: &SourceComponent, _ctx: &mut ComponentCloneCtx) {}
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/// Wrapper for components clone specialization using autoderef.
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#[doc(hidden)]
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pub struct DefaultCloneBehaviorSpecialization<T>(PhantomData<T>);
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|
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impl<T> Default for DefaultCloneBehaviorSpecialization<T> {
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fn default() -> Self {
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|
Self(PhantomData)
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}
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}
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/// Base trait for components clone specialization using autoderef.
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#[doc(hidden)]
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pub trait DefaultCloneBehaviorBase {
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fn default_clone_behavior(&self) -> ComponentCloneBehavior;
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}
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impl<C> DefaultCloneBehaviorBase for DefaultCloneBehaviorSpecialization<C> {
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fn default_clone_behavior(&self) -> ComponentCloneBehavior {
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|
ComponentCloneBehavior::Default
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|
}
|
|
}
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|
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/// Specialized trait for components clone specialization using autoderef.
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|
#[doc(hidden)]
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|
pub trait DefaultCloneBehaviorViaClone {
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|
fn default_clone_behavior(&self) -> ComponentCloneBehavior;
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|
}
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impl<C: Clone + Component> DefaultCloneBehaviorViaClone for &DefaultCloneBehaviorSpecialization<C> {
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|
fn default_clone_behavior(&self) -> ComponentCloneBehavior {
|
|
ComponentCloneBehavior::clone::<C>()
|
|
}
|
|
}
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