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mod.rs
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mod entity_ref;
mod pointer;
mod spawn_batch;
mod world_cell;
pub use entity_ref::*;
pub use pointer::*;
pub use spawn_batch::*;
pub use world_cell::*;
use crate::{
archetype::{ArchetypeComponentId, ArchetypeComponentInfo, ArchetypeId, Archetypes},
bundle::{Bundle, Bundles},
component::{
Component, ComponentDescriptor, ComponentId, ComponentTicks, Components, ComponentsError,
StorageType,
},
entity::{Entities, Entity},
query::{FilterFetch, QueryState, WorldQuery},
storage::{Column, SparseSet, Storages},
};
use std::{
any::TypeId,
fmt,
sync::atomic::{AtomicU32, Ordering},
};
#[derive(Copy, Clone, PartialEq, Eq, Debug)]
pub struct WorldId(u64);
impl Default for WorldId {
fn default() -> Self {
WorldId(rand::random())
}
}
/// [World] stores and exposes operations on [entities](Entity), [components](Component),
/// and their associated metadata.
/// Each [Entity] has a set of components. Each component can have up to one instance of each
/// component type. Entity components can be created, updated, removed, and queried using a given
/// [World].
pub struct World {
id: WorldId,
pub(crate) entities: Entities,
pub(crate) components: Components,
pub(crate) archetypes: Archetypes,
pub(crate) storages: Storages,
pub(crate) bundles: Bundles,
pub(crate) removed_components: SparseSet<ComponentId, Vec<Entity>>,
/// Access cache used by [WorldCell].
pub(crate) archetype_component_access: ArchetypeComponentAccess,
main_thread_validator: MainThreadValidator,
pub(crate) change_tick: AtomicU32,
pub(crate) last_change_tick: u32,
}
impl Default for World {
fn default() -> Self {
Self {
id: Default::default(),
entities: Default::default(),
components: Default::default(),
archetypes: Default::default(),
storages: Default::default(),
bundles: Default::default(),
removed_components: Default::default(),
archetype_component_access: Default::default(),
main_thread_validator: Default::default(),
// Default value is `1`, and `last_change_tick`s default to `0`, such that changes
// are detected on first system runs and for direct world queries.
change_tick: AtomicU32::new(1),
last_change_tick: 0,
}
}
}
impl World {
/// Creates a new empty [World]
#[inline]
pub fn new() -> World {
World::default()
}
/// Retrieves this world's unique ID
#[inline]
pub fn id(&self) -> WorldId {
self.id
}
/// Retrieves this world's [Entities] collection
#[inline]
pub fn entities(&self) -> &Entities {
&self.entities
}
/// Retrieves this world's [Archetypes] collection
#[inline]
pub fn archetypes(&self) -> &Archetypes {
&self.archetypes
}
/// Retrieves this world's [Components] collection
#[inline]
pub fn components(&self) -> &Components {
&self.components
}
/// Retrieves a mutable reference to this world's [Components] collection
#[inline]
pub fn components_mut(&mut self) -> &mut Components {
&mut self.components
}
/// Retrieves this world's [Storages] collection
#[inline]
pub fn storages(&self) -> &Storages {
&self.storages
}
/// Retrieves this world's [Bundles] collection
#[inline]
pub fn bundles(&self) -> &Bundles {
&self.bundles
}
/// Retrieves a [WorldCell], which safely enables multiple mutable World accesses at the same
/// time, provided those accesses do not conflict with each other.
#[inline]
pub fn cell(&mut self) -> WorldCell<'_> {
WorldCell::new(self)
}
/// Registers a new component using the given [ComponentDescriptor]. Components do not need to
/// be manually registered. This just provides a way to override default configuration.
/// Attempting to register a component with a type that has already been used by [World]
/// will result in an error.
///
/// The default component storage type can be overridden like this:
///
/// ```
/// use bevy_ecs::{component::{ComponentDescriptor, StorageType}, world::World};
///
/// struct Position {
/// x: f32,
/// y: f32,
/// }
///
/// let mut world = World::new();
/// world.register_component(ComponentDescriptor::new::<Position>(StorageType::SparseSet)).unwrap();
/// ```
pub fn register_component(
&mut self,
descriptor: ComponentDescriptor,
) -> Result<ComponentId, ComponentsError> {
let storage_type = descriptor.storage_type();
let component_id = self.components.add(descriptor)?;
// ensure sparse set is created for SparseSet components
if storage_type == StorageType::SparseSet {
// SAFE: just created
let info = unsafe { self.components.get_info_unchecked(component_id) };
self.storages.sparse_sets.get_or_insert(info);
}
Ok(component_id)
}
/// Retrieves an [EntityRef] that exposes read-only operations for the given `entity`.
/// This will panic if the `entity` does not exist. Use [World::get_entity] if you want
/// to check for entity existence instead of implicitly panic-ing.
///
/// ```
/// use bevy_ecs::world::World;
///
/// struct Position {
/// x: f32,
/// y: f32,
/// }
///
/// let mut world = World::new();
/// let entity = world.spawn()
/// .insert(Position { x: 0.0, y: 0.0 })
/// .id();
///
/// let position = world.entity(entity).get::<Position>().unwrap();
/// assert_eq!(position.x, 0.0);
/// ```
#[inline]
pub fn entity(&self, entity: Entity) -> EntityRef {
self.get_entity(entity).expect("Entity does not exist")
}
/// Retrieves an [EntityMut] that exposes read and write operations for the given `entity`.
/// This will panic if the `entity` does not exist. Use [World::get_entity_mut] if you want
/// to check for entity existence instead of implicitly panic-ing.
///
/// ```
/// use bevy_ecs::world::World;
///
/// struct Position {
/// x: f32,
/// y: f32,
/// }
///
/// let mut world = World::new();
/// let entity = world.spawn()
/// .insert(Position { x: 0.0, y: 0.0 })
/// .id();
///
/// let mut position = world.entity_mut(entity).get_mut::<Position>().unwrap();
/// position.x = 1.0;
/// ```
#[inline]
pub fn entity_mut(&mut self, entity: Entity) -> EntityMut {
self.get_entity_mut(entity).expect("Entity does not exist")
}
/// Retrieves an [EntityRef] that exposes read-only operations for the given `entity`.
/// Returns [None] if the `entity` does not exist. Use [World::entity] if you don't want
/// to unwrap the [EntityRef] yourself.
///
/// ```
/// use bevy_ecs::world::World;
///
/// struct Position {
/// x: f32,
/// y: f32,
/// }
///
/// let mut world = World::new();
/// let entity = world.spawn()
/// .insert(Position { x: 0.0, y: 0.0 })
/// .id();
///
/// let entity_ref = world.get_entity(entity).unwrap();
/// let position = entity_ref.get::<Position>().unwrap();
/// assert_eq!(position.x, 0.0);
/// ```
#[inline]
pub fn get_entity(&self, entity: Entity) -> Option<EntityRef> {
let location = self.entities.get(entity)?;
Some(EntityRef::new(self, entity, location))
}
/// Retrieves an [EntityMut] that exposes read and write operations for the given `entity`.
/// Returns [None] if the `entity` does not exist. Use [World::entity_mut] if you don't want
/// to unwrap the [EntityMut] yourself.
///
/// ```
/// use bevy_ecs::world::World;
///
/// struct Position {
/// x: f32,
/// y: f32,
/// }
///
/// let mut world = World::new();
/// let entity = world.spawn()
/// .insert(Position { x: 0.0, y: 0.0 })
/// .id();
///
/// let mut entity_mut = world.get_entity_mut(entity).unwrap();
/// let mut position = entity_mut.get_mut::<Position>().unwrap();
/// position.x = 1.0;
/// ```
#[inline]
pub fn get_entity_mut(&mut self, entity: Entity) -> Option<EntityMut> {
let location = self.entities.get(entity)?;
// SAFE: `entity` exists and `location` is that entity's location
Some(unsafe { EntityMut::new(self, entity, location) })
}
/// Spawns a new [Entity] and returns a corresponding [EntityMut], which can be used
/// to add components to the entity or retrieve its id.
///
/// ```
/// use bevy_ecs::world::World;
///
/// struct Position {
/// x: f32,
/// y: f32,
/// }
///
/// let mut world = World::new();
/// let entity = world.spawn()
/// .insert(Position { x: 0.0, y: 0.0 }) // add a single component
/// .insert_bundle((1, 2.0, "hello")) // add a bundle of components
/// .id();
///
/// let position = world.entity(entity).get::<Position>().unwrap();
/// assert_eq!(position.x, 0.0);
/// ```
pub fn spawn(&mut self) -> EntityMut {
self.flush();
let entity = self.entities.alloc();
let archetype = self.archetypes.empty_mut();
unsafe {
// PERF: consider avoiding allocating entities in the empty archetype unless needed
let table_row = self.storages.tables[archetype.table_id()].allocate(entity);
// SAFE: no components are allocated by archetype.allocate() because the archetype is
// empty
let location = archetype.allocate(entity, table_row);
// SAFE: entity index was just allocated
self.entities
.meta
.get_unchecked_mut(entity.id() as usize)
.location = location;
EntityMut::new(self, entity, location)
}
}
/// Spawns a batch of entities with the same component [Bundle] type. Takes a given [Bundle]
/// iterator and returns a corresponding [Entity] iterator.
/// This is more efficient than spawning entities and adding components to them individually,
/// but it is limited to spawning entities with the same [Bundle] type, whereas spawning
/// individually is more flexible.
///
/// ```
/// use bevy_ecs::{entity::Entity, world::World};
///
/// let mut world = World::new();
/// let entities = world.spawn_batch(vec![
/// ("a", 0.0), // the first entity
/// ("b", 1.0), // the second entity
/// ]).collect::<Vec<Entity>>();
///
/// assert_eq!(entities.len(), 2);
/// ```
pub fn spawn_batch<I>(&mut self, iter: I) -> SpawnBatchIter<'_, I::IntoIter>
where
I: IntoIterator,
I::Item: Bundle,
{
SpawnBatchIter::new(self, iter.into_iter())
}
/// Retrieves a reference to the given `entity`'s [Component] of the given type.
/// Returns [None] if the `entity` does not have a [Component] of the given type.
/// ```
/// use bevy_ecs::world::World;
///
/// struct Position {
/// x: f32,
/// y: f32,
/// }
///
/// let mut world = World::new();
/// let entity = world.spawn()
/// .insert(Position { x: 0.0, y: 0.0 })
/// .id();
/// let position = world.get::<Position>(entity).unwrap();
/// assert_eq!(position.x, 0.0);
#[inline]
pub fn get<T: Component>(&self, entity: Entity) -> Option<&T> {
self.get_entity(entity)?.get()
}
/// Retrieves a mutable reference to the given `entity`'s [Component] of the given type.
/// Returns [None] if the `entity` does not have a [Component] of the given type.
/// ```
/// use bevy_ecs::world::World;
///
/// struct Position {
/// x: f32,
/// y: f32,
/// }
///
/// let mut world = World::new();
/// let entity = world.spawn()
/// .insert(Position { x: 0.0, y: 0.0 })
/// .id();
/// let mut position = world.get_mut::<Position>(entity).unwrap();
/// position.x = 1.0;
#[inline]
pub fn get_mut<T: Component>(&mut self, entity: Entity) -> Option<Mut<T>> {
self.get_entity_mut(entity)?.get_mut()
}
/// Despawns the given `entity`, if it exists. This will also remove all of the entity's
/// [Component]s. Returns `true` if the `entity` is successfully despawned and `false` if
/// the `entity` does not exist.
/// ```
/// use bevy_ecs::world::World;
///
/// struct Position {
/// x: f32,
/// y: f32,
/// }
///
/// let mut world = World::new();
/// let entity = world.spawn()
/// .insert(Position { x: 0.0, y: 0.0 })
/// .id();
/// assert!(world.despawn(entity));
/// assert!(world.get_entity(entity).is_none());
/// assert!(world.get::<Position>(entity).is_none());
/// ```
#[inline]
pub fn despawn(&mut self, entity: Entity) -> bool {
self.get_entity_mut(entity)
.map(|e| {
e.despawn();
true
})
.unwrap_or(false)
}
/// Clears component tracker state
pub fn clear_trackers(&mut self) {
for entities in self.removed_components.values_mut() {
entities.clear();
}
self.last_change_tick = self.increment_change_tick();
}
/// Returns [QueryState] for the given [WorldQuery], which is used to efficiently
/// run queries on the [World] by storing and reusing the [QueryState].
/// ```
/// use bevy_ecs::{entity::Entity, world::World};
///
/// #[derive(Debug, PartialEq)]
/// struct Position {
/// x: f32,
/// y: f32,
/// }
///
/// struct Velocity {
/// x: f32,
/// y: f32,
/// }
///
/// let mut world = World::new();
/// let entities = world.spawn_batch(vec![
/// (Position { x: 0.0, y: 0.0}, Velocity { x: 1.0, y: 0.0 }),
/// (Position { x: 0.0, y: 0.0}, Velocity { x: 0.0, y: 1.0 }),
/// ]).collect::<Vec<Entity>>();
///
/// let mut query = world.query::<(&mut Position, &Velocity)>();
/// for (mut position, velocity) in query.iter_mut(&mut world) {
/// position.x += velocity.x;
/// position.y += velocity.y;
/// }
///
/// assert_eq!(world.get::<Position>(entities[0]).unwrap(), &Position { x: 1.0, y: 0.0 });
/// assert_eq!(world.get::<Position>(entities[1]).unwrap(), &Position { x: 0.0, y: 1.0 });
/// ```
///
/// To iterate over entities in a deterministic order,
/// sort the results of the query using the desired component as a key.
/// Note that this requires fetching the whole result set from the query
/// and allocation of a [Vec] to store it.
///
/// ```
/// use bevy_ecs::{entity::Entity, world::World};
/// let mut world = World::new();
/// let a = world.spawn().insert_bundle((2, 4.0)).id();
/// let b = world.spawn().insert_bundle((3, 5.0)).id();
/// let c = world.spawn().insert_bundle((1, 6.0)).id();
/// let mut entities = world.query::<(Entity, &i32, &f64)>()
/// .iter(&world)
/// .collect::<Vec<_>>();
/// // Sort the query results by their `i32` component before comparing
/// // to expected results. Query iteration order should not be relied on.
/// entities.sort_by_key(|e| e.1);
/// assert_eq!(entities, vec![(c, &1, &6.0), (a, &2, &4.0), (b, &3, &5.0)]);
/// ```
#[inline]
pub fn query<Q: WorldQuery>(&mut self) -> QueryState<Q, ()> {
QueryState::new(self)
}
/// Returns [QueryState] for the given filtered [WorldQuery], which is used to efficiently
/// run queries on the [World] by storing and reusing the [QueryState].
/// ```
/// use bevy_ecs::{entity::Entity, world::World, query::With};
///
/// struct A;
/// struct B;
///
/// let mut world = World::new();
/// let e1 = world.spawn().insert(A).id();
/// let e2 = world.spawn().insert_bundle((A, B)).id();
///
/// let mut query = world.query_filtered::<Entity, With<B>>();
/// let matching_entities = query.iter(&world).collect::<Vec<Entity>>();
///
/// assert_eq!(matching_entities, vec![e2]);
/// ```
#[inline]
pub fn query_filtered<Q: WorldQuery, F: WorldQuery>(&mut self) -> QueryState<Q, F>
where
F::Fetch: FilterFetch,
{
QueryState::new(self)
}
/// Returns an iterator of entities that had components of type `T` removed
/// since the last call to [World::clear_trackers].
pub fn removed<T: Component>(&self) -> std::iter::Cloned<std::slice::Iter<'_, Entity>> {
if let Some(component_id) = self.components.get_id(TypeId::of::<T>()) {
self.removed_with_id(component_id)
} else {
[].iter().cloned()
}
}
/// Returns an iterator of entities that had components with the given `component_id` removed
/// since the last call to [World::clear_trackers].
pub fn removed_with_id(
&self,
component_id: ComponentId,
) -> std::iter::Cloned<std::slice::Iter<'_, Entity>> {
if let Some(removed) = self.removed_components.get(component_id) {
removed.iter().cloned()
} else {
[].iter().cloned()
}
}
/// Inserts a new resource with the given `value`.
/// Resources are "unique" data of a given type.
#[inline]
pub fn insert_resource<T: Component>(&mut self, value: T) {
let component_id = self.components.get_or_insert_resource_id::<T>();
// SAFE: component_id just initialized and corresponds to resource of type T
unsafe { self.insert_resource_with_id(component_id, value) };
}
/// Inserts a new non-send resource with the given `value`.
/// Resources are "unique" data of a given type.
#[inline]
pub fn insert_non_send<T: 'static>(&mut self, value: T) {
self.validate_non_send_access::<T>();
let component_id = self.components.get_or_insert_non_send_resource_id::<T>();
// SAFE: component_id just initialized and corresponds to resource of type T
unsafe { self.insert_resource_with_id(component_id, value) };
}
/// Removes the resource of a given type and returns it, if it exists. Otherwise returns [None].
/// Resources are "unique" data of a given type.
#[inline]
pub fn remove_resource<T: Component>(&mut self) -> Option<T> {
// SAFE: T is Send + Sync
unsafe { self.remove_resource_unchecked() }
}
#[inline]
pub fn remove_non_send<T: 'static>(&mut self) -> Option<T> {
self.validate_non_send_access::<T>();
// SAFE: we are on main thread
unsafe { self.remove_resource_unchecked() }
}
#[inline]
/// # Safety
/// make sure you're on main thread if T isn't Send + Sync
#[allow(unused_unsafe)]
pub unsafe fn remove_resource_unchecked<T: 'static>(&mut self) -> Option<T> {
let component_id = self.components.get_resource_id(TypeId::of::<T>())?;
let resource_archetype = self.archetypes.resource_mut();
let unique_components = resource_archetype.unique_components_mut();
let column = unique_components.get_mut(component_id)?;
if column.is_empty() {
return None;
}
// SAFE: if a resource column exists, row 0 exists as well. caller takes ownership of the
// ptr value / drop is called when T is dropped
let (ptr, _) = unsafe { column.swap_remove_and_forget_unchecked(0) };
// SAFE: column is of type T
Some(unsafe { ptr.cast::<T>().read() })
}
/// Returns `true` if a resource of type `T` exists. Otherwise returns `false`.
#[inline]
pub fn contains_resource<T: Component>(&self) -> bool {
let component_id =
if let Some(component_id) = self.components.get_resource_id(TypeId::of::<T>()) {
component_id
} else {
return false;
};
self.get_populated_resource_column(component_id).is_some()
}
/// Gets a reference to the resource of the given type, if it exists. Otherwise returns [None]
/// Resources are "unique" data of a given type.
#[inline]
pub fn get_resource<T: Component>(&self) -> Option<&T> {
let component_id = self.components.get_resource_id(TypeId::of::<T>())?;
unsafe { self.get_resource_with_id(component_id) }
}
pub fn is_resource_added<T: Component>(&self) -> bool {
let component_id = self.components.get_resource_id(TypeId::of::<T>()).unwrap();
let column = self.get_populated_resource_column(component_id).unwrap();
let ticks = unsafe { &*column.get_ticks_mut_ptr() };
ticks.is_added(self.last_change_tick(), self.read_change_tick())
}
pub fn is_resource_changed<T: Component>(&self) -> bool {
let component_id = self.components.get_resource_id(TypeId::of::<T>()).unwrap();
let column = self.get_populated_resource_column(component_id).unwrap();
let ticks = unsafe { &*column.get_ticks_mut_ptr() };
ticks.is_changed(self.last_change_tick(), self.read_change_tick())
}
/// Gets a mutable reference to the resource of the given type, if it exists. Otherwise returns
/// [None] Resources are "unique" data of a given type.
#[inline]
pub fn get_resource_mut<T: Component>(&mut self) -> Option<Mut<'_, T>> {
// SAFE: unique world access
unsafe { self.get_resource_unchecked_mut() }
}
// PERF: optimize this to avoid redundant lookups
/// Gets a resource of type `T` if it exists, otherwise inserts the resource using the result of
/// calling `func`.
#[inline]
pub fn get_resource_or_insert_with<T: Component>(
&mut self,
func: impl FnOnce() -> T,
) -> Mut<'_, T> {
if !self.contains_resource::<T>() {
self.insert_resource(func());
}
self.get_resource_mut().unwrap()
}
/// Gets a mutable reference to the resource of the given type, if it exists. Otherwise returns
/// [None] Resources are "unique" data of a given type.
///
/// # Safety
/// This will allow aliased mutable access to the given resource type. The caller must ensure
/// that only one mutable access exists at a time.
#[inline]
pub unsafe fn get_resource_unchecked_mut<T: Component>(&self) -> Option<Mut<'_, T>> {
let component_id = self.components.get_resource_id(TypeId::of::<T>())?;
self.get_resource_unchecked_mut_with_id(component_id)
}
/// Gets a reference to the non-send resource of the given type, if it exists. Otherwise returns
/// [None] Resources are "unique" data of a given type.
#[inline]
pub fn get_non_send_resource<T: 'static>(&self) -> Option<&T> {
let component_id = self.components.get_resource_id(TypeId::of::<T>())?;
// SAFE: component id matches type T
unsafe { self.get_non_send_with_id(component_id) }
}
/// Gets a mutable reference to the non-send resource of the given type, if it exists. Otherwise
/// returns [None] Resources are "unique" data of a given type.
#[inline]
pub fn get_non_send_resource_mut<T: 'static>(&mut self) -> Option<Mut<'_, T>> {
// SAFE: unique world access
unsafe { self.get_non_send_resource_unchecked_mut() }
}
/// Gets a mutable reference to the non-send resource of the given type, if it exists. Otherwise
/// returns [None] Resources are "unique" data of a given type.
///
/// # Safety
/// This will allow aliased mutable access to the given non-send resource type. The caller must
/// ensure that only one mutable access exists at a time.
#[inline]
pub unsafe fn get_non_send_resource_unchecked_mut<T: 'static>(&self) -> Option<Mut<'_, T>> {
let component_id = self.components.get_resource_id(TypeId::of::<T>())?;
self.get_non_send_unchecked_mut_with_id(component_id)
}
/// Temporarily removes the requested resource from this [World], then re-adds it before
/// returning. This enables safe mutable access to a resource while still providing mutable
/// world access
/// ```
/// use bevy_ecs::world::{World, Mut};
/// struct A(u32);
/// struct B(u32);
/// let mut world = World::new();
/// world.insert_resource(A(1));
/// let entity = world.spawn().insert(B(1)).id();
///
/// world.resource_scope(|world, mut a: Mut<A>| {
/// let b = world.get_mut::<B>(entity).unwrap();
/// a.0 += b.0;
/// });
/// assert_eq!(world.get_resource::<A>().unwrap().0, 2);
/// ```
pub fn resource_scope<T: Component, U>(
&mut self,
f: impl FnOnce(&mut World, Mut<T>) -> U,
) -> U {
let component_id = self
.components
.get_resource_id(TypeId::of::<T>())
.unwrap_or_else(|| panic!("resource does not exist: {}", std::any::type_name::<T>()));
let (ptr, mut ticks) = {
let resource_archetype = self.archetypes.resource_mut();
let unique_components = resource_archetype.unique_components_mut();
let column = unique_components.get_mut(component_id).unwrap_or_else(|| {
panic!("resource does not exist: {}", std::any::type_name::<T>())
});
if column.is_empty() {
panic!("resource does not exist: {}", std::any::type_name::<T>());
}
// SAFE: if a resource column exists, row 0 exists as well. caller takes ownership of
// the ptr value / drop is called when T is dropped
unsafe { column.swap_remove_and_forget_unchecked(0) }
};
// SAFE: pointer is of type T
let value = Mut {
value: unsafe { &mut *ptr.cast::<T>() },
component_ticks: &mut ticks,
last_change_tick: self.last_change_tick(),
change_tick: self.change_tick(),
};
let result = f(self, value);
let resource_archetype = self.archetypes.resource_mut();
let unique_components = resource_archetype.unique_components_mut();
let column = unique_components
.get_mut(component_id)
.unwrap_or_else(|| panic!("resource does not exist: {}", std::any::type_name::<T>()));
// SAFE: new location is immediately written to below
let row = unsafe { column.push_uninit() };
// SAFE: row was just allocated above
unsafe { column.set_unchecked(row, ptr) };
// SAFE: row was just allocated above
unsafe { *column.get_ticks_unchecked_mut(row) = ticks };
result
}
/// # Safety
/// `component_id` must be assigned to a component of type T
#[inline]
pub(crate) unsafe fn get_resource_with_id<T: 'static>(
&self,
component_id: ComponentId,
) -> Option<&T> {
let column = self.get_populated_resource_column(component_id)?;
Some(&*column.get_ptr().as_ptr().cast::<T>())
}
/// # Safety
/// `component_id` must be assigned to a component of type T.
/// Caller must ensure this doesn't violate Rust mutability rules for the given resource.
#[inline]
pub(crate) unsafe fn get_resource_unchecked_mut_with_id<T>(
&self,
component_id: ComponentId,
) -> Option<Mut<'_, T>> {
let column = self.get_populated_resource_column(component_id)?;
Some(Mut {
value: &mut *column.get_ptr().as_ptr().cast::<T>(),
component_ticks: &mut *column.get_ticks_mut_ptr(),
last_change_tick: self.last_change_tick(),
change_tick: self.read_change_tick(),
})
}
/// # Safety
/// `component_id` must be assigned to a component of type T
#[inline]
pub(crate) unsafe fn get_non_send_with_id<T: 'static>(
&self,
component_id: ComponentId,
) -> Option<&T> {
self.validate_non_send_access::<T>();
self.get_resource_with_id(component_id)
}
/// # Safety
/// `component_id` must be assigned to a component of type T.
/// Caller must ensure this doesn't violate Rust mutability rules for the given resource.
#[inline]
pub(crate) unsafe fn get_non_send_unchecked_mut_with_id<T: 'static>(
&self,
component_id: ComponentId,
) -> Option<Mut<'_, T>> {
self.validate_non_send_access::<T>();
self.get_resource_unchecked_mut_with_id(component_id)
}
/// # Safety
/// `component_id` must be valid and correspond to a resource component of type T
#[inline]
unsafe fn insert_resource_with_id<T>(&mut self, component_id: ComponentId, mut value: T) {
let change_tick = self.change_tick();
let column = self.initialize_resource_internal(component_id);
if column.is_empty() {
// SAFE: column is of type T and has been allocated above
let data = (&mut value as *mut T).cast::<u8>();
// SAFE: new location is immediately written to below
let row = column.push_uninit();
// SAFE: index was just allocated above
column.set_unchecked(row, data);
std::mem::forget(value);
// SAFE: index was just allocated above
*column.get_ticks_unchecked_mut(row) = ComponentTicks::new(change_tick);
} else {
// SAFE: column is of type T and has already been allocated
*column.get_unchecked(0).cast::<T>() = value;
column.get_ticks_unchecked_mut(0).set_changed(change_tick);
}
}
/// # Safety
/// `component_id` must be valid and correspond to a resource component of type T
#[inline]
unsafe fn initialize_resource_internal(&mut self, component_id: ComponentId) -> &mut Column {
// SAFE: resource archetype always exists
let resource_archetype = self
.archetypes
.archetypes
.get_unchecked_mut(ArchetypeId::resource().index());
let resource_archetype_components = &mut resource_archetype.components;
let archetype_component_count = &mut self.archetypes.archetype_component_count;
let components = &self.components;
resource_archetype
.unique_components
.get_or_insert_with(component_id, || {
resource_archetype_components.insert(
component_id,
ArchetypeComponentInfo {
archetype_component_id: ArchetypeComponentId::new(
*archetype_component_count,
),
storage_type: StorageType::Table,
},
);
*archetype_component_count += 1;
let component_info = components.get_info_unchecked(component_id);
Column::with_capacity(component_info, 1)
})
}
pub(crate) fn initialize_resource<T: Component>(&mut self) -> ComponentId {
let component_id = self.components.get_or_insert_resource_id::<T>();
// SAFE: resource initialized above
unsafe { self.initialize_resource_internal(component_id) };
component_id
}
pub(crate) fn initialize_non_send_resource<T: 'static>(&mut self) -> ComponentId {
let component_id = self.components.get_or_insert_non_send_resource_id::<T>();
// SAFE: resource initialized above
unsafe { self.initialize_resource_internal(component_id) };
component_id
}
/// returns the resource column if the requested resource exists
pub(crate) fn get_populated_resource_column(
&self,
component_id: ComponentId,
) -> Option<&Column> {
let resource_archetype = self.archetypes.resource();
let unique_components = resource_archetype.unique_components();
unique_components.get(component_id).and_then(|column| {
if column.is_empty() {
None
} else {
Some(column)
}
})
}
pub(crate) fn validate_non_send_access<T: 'static>(&self) {
if !self.main_thread_validator.is_main_thread() {
panic!(
"attempted to access NonSend resource {} off of the main thread",
std::any::type_name::<T>()
);
}
}
/// Empties queued entities and adds them to the empty [Archetype].
/// This should be called before doing operations that might operate on queued entities,
/// such as inserting a [Component].
pub(crate) fn flush(&mut self) {
let empty_archetype = self.archetypes.empty_mut();
unsafe {
let table = &mut self.storages.tables[empty_archetype.table_id()];
// PERF: consider pre-allocating space for flushed entities
self.entities.flush(|entity, location| {
// SAFE: no components are allocated by archetype.allocate() because the archetype
// is empty
*location = empty_archetype.allocate(entity, table.allocate(entity));
});
}
}
#[inline]
pub fn increment_change_tick(&self) -> u32 {
self.change_tick.fetch_add(1, Ordering::AcqRel)
}
#[inline]
pub fn read_change_tick(&self) -> u32 {
self.change_tick.load(Ordering::Acquire)
}
#[inline]
pub fn change_tick(&mut self) -> u32 {
*self.change_tick.get_mut()
}
#[inline]
pub fn last_change_tick(&self) -> u32 {
self.last_change_tick
}
pub fn check_change_ticks(&mut self) {
// Iterate over all component change ticks, clamping their age to max age
// PERF: parallelize
let change_tick = self.change_tick();
self.storages.tables.check_change_ticks(change_tick);
self.storages.sparse_sets.check_change_ticks(change_tick);
let resource_archetype = self.archetypes.resource_mut();
for column in resource_archetype.unique_components.values_mut() {
column.check_change_ticks(change_tick);
}
}
}
impl fmt::Debug for World {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
f.debug_struct("World")
.field("id", &self.id)
.field("entity_count", &self.entities.len())
.field("archetype_count", &self.archetypes.len())
.field("component_count", &self.components.len())
.field(
"resource_count",
&self.archetypes.resource().unique_components.len(),
)
.finish()
}
}
unsafe impl Send for World {}
unsafe impl Sync for World {}
/// Creates `Self` using data from the given [World]
pub trait FromWorld {
/// Creates `Self` using data from the given [World]
fn from_world(world: &mut World) -> Self;
}
impl<T: Default> FromWorld for T {
fn from_world(_world: &mut World) -> Self {
T::default()
}
}
struct MainThreadValidator {
main_thread: std::thread::ThreadId,
}
impl MainThreadValidator {
fn is_main_thread(&self) -> bool {
self.main_thread == std::thread::current().id()
}
}
impl Default for MainThreadValidator {
fn default() -> Self {
Self {
main_thread: std::thread::current().id(),
}
}
}