bevy/crates/bevy_ecs/src/bundle.rs
Daniel McNab 1a2aedd165 Implement Bundle for Component. Use Bundle tuples for insertion (#2975)
@BoxyUwU this is your fault. 

Also cart didn't arrive in time to tell us not to do this.

# Objective

- Fix #2974

## Solution

- The first commit just does the actual change
- Follow up commits do steps to prove that this method works to unify as required, but this does not remove `insert_bundle`.

## Changelog

### Changed
Nested bundles now collapse automatically, and every `Component` now implements `Bundle`.
This means that you can combine bundles and components arbitrarily, for example:
```rust
// before:
.insert(A).insert_bundle(MyBBundle{..})
// after:
.insert_bundle((A, MyBBundle {..}))
```

Note that there will be a follow up PR that removes the current `insert` impl and renames `insert_bundle` to `insert`.

### Removed
The `bundle` attribute in `derive(Bundle)`.

## Migration guide

In `derive(Bundle)`, the `bundle` attribute has been removed. Nested bundles are not collapsed automatically. You should remove `#[bundle]` attributes.

Co-authored-by: Carter Anderson <mcanders1@gmail.com>
2022-09-20 20:17:08 +00:00

734 lines
27 KiB
Rust

//! Types for handling [`Bundle`]s.
//!
//! This module contains the [`Bundle`] trait and some other helper types.
pub use bevy_ecs_macros::Bundle;
use crate::{
archetype::{AddBundle, Archetype, ArchetypeId, Archetypes, ComponentStatus},
component::{Component, ComponentId, ComponentTicks, Components, StorageType},
entity::{Entities, Entity, EntityLocation},
storage::{SparseSetIndex, SparseSets, Storages, Table},
};
use bevy_ecs_macros::all_tuples;
use bevy_ptr::OwningPtr;
use std::{any::TypeId, collections::HashMap};
/// The `Bundle` trait enables insertion and removal of [`Component`]s from an entity.
///
/// Implementors of the `Bundle` trait are called 'bundles'.
///
/// Each bundle represents a static set of [`Component`] types.
/// Currently, bundles can only contain one of each [`Component`], and will
/// panic once initialised if this is not met.
///
/// ## Insertion
///
/// The primary use for bundles is to add a useful collection of components to an entity.
///
/// Adding a value of bundle to an entity will add the components from the set it
/// represents to the entity.
/// The values of these components are taken from the bundle.
/// If an entity already had one of these components, the entity's original component value
/// will be overwritten.
///
/// Importantly, bundles are only their constituent set of components.
/// You **should not** use bundles as a unit of behaviour.
/// The behaviour of your app can only be considered in terms of components, as systems,
/// which drive the behaviour of a `bevy` application, operate on combinations of
/// components.
///
/// This rule is also important because multiple bundles may contain the same component type,
/// calculated in different ways &mdash; adding both of these bundles to one entity
/// would create incoherent behaviour.
/// This would be unexpected if bundles were treated as an abstraction boundary, as
/// the abstraction would be unmaintainable for these cases.
/// For example, both `Camera3dBundle` and `Camera2dBundle` contain the `CameraRenderGraph`
/// component, but specifying different render graphs to use.
/// If the bundles were both added to the same entity, only one of these two bundles would work.
///
/// For this reason, There is intentionally no [`Query`] to match whether an entity
/// contains the components of a bundle.
/// Queries should instead only select the components they logically operate on.
///
/// ## Removal
///
/// Bundles are also used when removing components from an entity.
///
/// Removing a bundle from an entity will remove any of its components attached
/// to the entity from the entity.
/// That is, if the entity does not have all the components of the bundle, those
/// which are present will be removed.
///
/// # Implementors
///
/// Every type which implements [`Component`] also implements `Bundle`, since
/// [`Component`] types can be added to or removed from an entity.
///
/// Additionally, [Tuples](`tuple`) of bundles are also [`Bundle`] (with up to 15 bundles).
/// These bundles contain the items of the 'inner' bundles.
/// This is a convenient shorthand which is primarily used when spawning entities.
/// For example, spawning an entity using the bundle `(SpriteBundle {...}, PlayerMarker)`
/// will spawn an entity with components required for a 2d sprite, and the `PlayerMarker` component.
///
/// [`unit`], otherwise known as [`()`](`unit`), is a [`Bundle`] containing no components (since it
/// can also be considered as the empty tuple).
/// This can be useful for spawning large numbers of empty entities using
/// [`World::spawn_batch`](crate::world::World::spawn_batch).
///
/// Tuple bundles can be nested, which can be used to create an anonymous bundle with more than
/// 15 items.
/// However, in most cases where this is required, the derive macro [`derive@Bundle`] should be
/// used instead.
/// The derived `Bundle` implementation contains the items of its fields, which all must
/// implement `Bundle`.
/// As explained above, this includes any [`Component`] type, and other derived bundles:
///
/// ```
/// # use bevy_ecs::{component::Component, bundle::Bundle};
///
/// #[derive(Component)]
/// struct XPosition(i32);
/// #[derive(Component)]
/// struct YPosition(i32);
///
/// #[derive(Bundle)]
/// struct PositionBundle {
/// // A bundle can contain components
/// x: XPosition,
/// y: YPosition,
/// }
///
/// #[derive(Bundle)]
/// struct NamedPointBundle {
/// // Or other bundles
/// a: PositionBundle,
/// // In addition to more components
/// z: PointName,
/// }
///
/// #[derive(Component)]
/// struct PointName(String);
/// ```
///
/// # Safety
///
/// Manual implementations of this trait are unsupported.
/// That is, there is no safe way to implement this trait, and you must not do so.
/// If you want a type to implement [`Bundle`], you must use [`derive@Bundle`](derive@Bundle).
///
///
/// [`Query`]: crate::system::Query
// Some safety points:
// - [`Bundle::component_ids`] must return the [`ComponentId`] for each component type in the
// bundle, in the _exact_ order that [`Bundle::get_components`] is called.
// - [`Bundle::from_components`] must call `func` exactly once for each [`ComponentId`] returned by
// [`Bundle::component_ids`].
pub unsafe trait Bundle: Send + Sync + 'static {
/// Gets this [`Bundle`]'s component ids, in the order of this bundle's [`Component`]s
#[doc(hidden)]
fn component_ids(
components: &mut Components,
storages: &mut Storages,
ids: &mut impl FnMut(ComponentId),
);
/// Calls `func`, which should return data for each component in the bundle, in the order of
/// this bundle's [`Component`]s
///
/// # Safety
/// Caller must return data for each component in the bundle, in the order of this bundle's
/// [`Component`]s
#[doc(hidden)]
unsafe fn from_components<T, F>(ctx: &mut T, func: &mut F) -> Self
where
// Ensure that the `OwningPtr` is used correctly
F: for<'a> FnMut(&'a mut T) -> OwningPtr<'a>,
Self: Sized;
/// Calls `func` on each value, in the order of this bundle's [`Component`]s. This passes
/// ownership of the component values to `func`.
#[doc(hidden)]
fn get_components(self, func: &mut impl FnMut(OwningPtr<'_>));
}
// SAFETY:
// - `Bundle::component_ids` calls `ids` for C's component id (and nothing else)
// - `Bundle::get_components` is called exactly once for C.
// - `Bundle::from_components` calls `func` exactly once for C, which is the exact value returned by `Bundle::component_ids`.
unsafe impl<C: Component> Bundle for C {
fn component_ids(
components: &mut Components,
storages: &mut Storages,
ids: &mut impl FnMut(ComponentId),
) {
ids(components.init_component::<C>(storages));
}
unsafe fn from_components<T, F>(ctx: &mut T, func: &mut F) -> Self
where
// Ensure that the `OwningPtr` is used correctly
F: for<'a> FnMut(&'a mut T) -> OwningPtr<'a>,
Self: Sized,
{
// Safety: The id given in `component_ids` is for `Self`
func(ctx).read()
}
fn get_components(self, func: &mut impl FnMut(OwningPtr<'_>)) {
OwningPtr::make(self, func);
}
}
macro_rules! tuple_impl {
($($name: ident),*) => {
// SAFETY:
// - `Bundle::component_ids` calls `ids` for each component type in the
// bundle, in the exact order that `Bundle::get_components` is called.
// - `Bundle::from_components` calls `func` exactly once for each `ComponentId` returned by `Bundle::component_ids`.
unsafe impl<$($name: Bundle),*> Bundle for ($($name,)*) {
#[allow(unused_variables)]
fn component_ids(components: &mut Components, storages: &mut Storages, ids: &mut impl FnMut(ComponentId)){
$(<$name as Bundle>::component_ids(components, storages, ids);)*
}
#[allow(unused_variables, unused_mut)]
#[allow(clippy::unused_unit)]
unsafe fn from_components<T, F>(ctx: &mut T, func: &mut F) -> Self
where
F: FnMut(&mut T) -> OwningPtr<'_>
{
// Rust guarantees that tuple calls are evaluated 'left to right'.
// https://doc.rust-lang.org/reference/expressions.html#evaluation-order-of-operands
($(<$name as Bundle>::from_components(ctx, func),)*)
}
#[allow(unused_variables, unused_mut)]
fn get_components(self, func: &mut impl FnMut(OwningPtr<'_>)) {
#[allow(non_snake_case)]
let ($(mut $name,)*) = self;
$(
$name.get_components(&mut *func);
)*
}
}
}
}
all_tuples!(tuple_impl, 0, 15, B);
#[derive(Debug, Clone, Copy, Eq, PartialEq, Hash)]
pub struct BundleId(usize);
impl BundleId {
#[inline]
pub fn index(self) -> usize {
self.0
}
}
impl SparseSetIndex for BundleId {
#[inline]
fn sparse_set_index(&self) -> usize {
self.index()
}
fn get_sparse_set_index(value: usize) -> Self {
Self(value)
}
}
pub struct BundleInfo {
pub(crate) id: BundleId,
pub(crate) component_ids: Vec<ComponentId>,
pub(crate) storage_types: Vec<StorageType>,
}
impl BundleInfo {
#[inline]
pub fn id(&self) -> BundleId {
self.id
}
#[inline]
pub fn components(&self) -> &[ComponentId] {
&self.component_ids
}
#[inline]
pub fn storage_types(&self) -> &[StorageType] {
&self.storage_types
}
pub(crate) fn get_bundle_inserter<'a, 'b>(
&'b self,
entities: &'a mut Entities,
archetypes: &'a mut Archetypes,
components: &mut Components,
storages: &'a mut Storages,
archetype_id: ArchetypeId,
change_tick: u32,
) -> BundleInserter<'a, 'b> {
let new_archetype_id =
self.add_bundle_to_archetype(archetypes, storages, components, archetype_id);
let archetypes_ptr = archetypes.archetypes.as_mut_ptr();
if new_archetype_id == archetype_id {
let archetype = &mut archetypes[archetype_id];
let table_id = archetype.table_id();
BundleInserter {
bundle_info: self,
archetype,
entities,
sparse_sets: &mut storages.sparse_sets,
table: &mut storages.tables[table_id],
archetypes_ptr,
change_tick,
result: InsertBundleResult::SameArchetype,
}
} else {
let (archetype, new_archetype) = archetypes.get_2_mut(archetype_id, new_archetype_id);
let table_id = archetype.table_id();
if table_id == new_archetype.table_id() {
BundleInserter {
bundle_info: self,
archetype,
archetypes_ptr,
entities,
sparse_sets: &mut storages.sparse_sets,
table: &mut storages.tables[table_id],
change_tick,
result: InsertBundleResult::NewArchetypeSameTable { new_archetype },
}
} else {
let (table, new_table) = storages
.tables
.get_2_mut(table_id, new_archetype.table_id());
BundleInserter {
bundle_info: self,
archetype,
sparse_sets: &mut storages.sparse_sets,
entities,
archetypes_ptr,
table,
change_tick,
result: InsertBundleResult::NewArchetypeNewTable {
new_archetype,
new_table,
},
}
}
}
}
pub(crate) fn get_bundle_spawner<'a, 'b>(
&'b self,
entities: &'a mut Entities,
archetypes: &'a mut Archetypes,
components: &mut Components,
storages: &'a mut Storages,
change_tick: u32,
) -> BundleSpawner<'a, 'b> {
let new_archetype_id =
self.add_bundle_to_archetype(archetypes, storages, components, ArchetypeId::EMPTY);
let (empty_archetype, archetype) =
archetypes.get_2_mut(ArchetypeId::EMPTY, new_archetype_id);
let table = &mut storages.tables[archetype.table_id()];
let add_bundle = empty_archetype.edges().get_add_bundle(self.id()).unwrap();
BundleSpawner {
archetype,
add_bundle,
bundle_info: self,
table,
entities,
sparse_sets: &mut storages.sparse_sets,
change_tick,
}
}
/// # Safety
/// `table` must be the "new" table for `entity`. `table_row` must have space allocated for the
/// `entity`, `bundle` must match this [`BundleInfo`]'s type
#[inline]
#[allow(clippy::too_many_arguments)]
unsafe fn write_components<T: Bundle>(
&self,
table: &mut Table,
sparse_sets: &mut SparseSets,
add_bundle: &AddBundle,
entity: Entity,
table_row: usize,
change_tick: u32,
bundle: T,
) {
// NOTE: get_components calls this closure on each component in "bundle order".
// bundle_info.component_ids are also in "bundle order"
let mut bundle_component = 0;
bundle.get_components(&mut |component_ptr| {
let component_id = *self.component_ids.get_unchecked(bundle_component);
match self.storage_types[bundle_component] {
StorageType::Table => {
let column = table.get_column_mut(component_id).unwrap();
match add_bundle.bundle_status.get_unchecked(bundle_component) {
ComponentStatus::Added => {
column.initialize(
table_row,
component_ptr,
ComponentTicks::new(change_tick),
);
}
ComponentStatus::Mutated => {
column.replace(table_row, component_ptr, change_tick);
}
}
}
StorageType::SparseSet => {
let sparse_set = sparse_sets.get_mut(component_id).unwrap();
sparse_set.insert(entity, component_ptr, change_tick);
}
}
bundle_component += 1;
});
}
/// Adds a bundle to the given archetype and returns the resulting archetype. This could be the
/// same [`ArchetypeId`], in the event that adding the given bundle does not result in an
/// [`Archetype`] change. Results are cached in the [`Archetype`] graph to avoid redundant work.
pub(crate) fn add_bundle_to_archetype(
&self,
archetypes: &mut Archetypes,
storages: &mut Storages,
components: &mut Components,
archetype_id: ArchetypeId,
) -> ArchetypeId {
if let Some(add_bundle) = archetypes[archetype_id].edges().get_add_bundle(self.id) {
return add_bundle.archetype_id;
}
let mut new_table_components = Vec::new();
let mut new_sparse_set_components = Vec::new();
let mut bundle_status = Vec::with_capacity(self.component_ids.len());
let current_archetype = &mut archetypes[archetype_id];
for component_id in self.component_ids.iter().cloned() {
if current_archetype.contains(component_id) {
bundle_status.push(ComponentStatus::Mutated);
} else {
bundle_status.push(ComponentStatus::Added);
// SAFETY: component_id exists
let component_info = unsafe { components.get_info_unchecked(component_id) };
match component_info.storage_type() {
StorageType::Table => new_table_components.push(component_id),
StorageType::SparseSet => new_sparse_set_components.push(component_id),
}
}
}
if new_table_components.is_empty() && new_sparse_set_components.is_empty() {
let edges = current_archetype.edges_mut();
// the archetype does not change when we add this bundle
edges.insert_add_bundle(self.id, archetype_id, bundle_status);
archetype_id
} else {
let table_id;
let table_components;
let sparse_set_components;
// the archetype changes when we add this bundle. prepare the new archetype and storages
{
let current_archetype = &archetypes[archetype_id];
table_components = if new_table_components.is_empty() {
// if there are no new table components, we can keep using this table
table_id = current_archetype.table_id();
current_archetype.table_components().to_vec()
} else {
new_table_components.extend(current_archetype.table_components());
// sort to ignore order while hashing
new_table_components.sort();
// SAFETY: all component ids in `new_table_components` exist
table_id = unsafe {
storages
.tables
.get_id_or_insert(&new_table_components, components)
};
new_table_components
};
sparse_set_components = if new_sparse_set_components.is_empty() {
current_archetype.sparse_set_components().to_vec()
} else {
new_sparse_set_components.extend(current_archetype.sparse_set_components());
// sort to ignore order while hashing
new_sparse_set_components.sort();
new_sparse_set_components
};
};
let new_archetype_id =
archetypes.get_id_or_insert(table_id, table_components, sparse_set_components);
// add an edge from the old archetype to the new archetype
archetypes[archetype_id].edges_mut().insert_add_bundle(
self.id,
new_archetype_id,
bundle_status,
);
new_archetype_id
}
}
}
pub(crate) struct BundleInserter<'a, 'b> {
pub(crate) archetype: &'a mut Archetype,
pub(crate) entities: &'a mut Entities,
bundle_info: &'b BundleInfo,
table: &'a mut Table,
sparse_sets: &'a mut SparseSets,
result: InsertBundleResult<'a>,
archetypes_ptr: *mut Archetype,
change_tick: u32,
}
pub(crate) enum InsertBundleResult<'a> {
SameArchetype,
NewArchetypeSameTable {
new_archetype: &'a mut Archetype,
},
NewArchetypeNewTable {
new_archetype: &'a mut Archetype,
new_table: &'a mut Table,
},
}
impl<'a, 'b> BundleInserter<'a, 'b> {
/// # Safety
/// `entity` must currently exist in the source archetype for this inserter. `archetype_index`
/// must be `entity`'s location in the archetype. `T` must match this [`BundleInfo`]'s type
#[inline]
pub unsafe fn insert<T: Bundle>(
&mut self,
entity: Entity,
archetype_index: usize,
bundle: T,
) -> EntityLocation {
let location = EntityLocation {
index: archetype_index,
archetype_id: self.archetype.id(),
};
match &mut self.result {
InsertBundleResult::SameArchetype => {
// PERF: this could be looked up during Inserter construction and stored (but borrowing makes this nasty)
let add_bundle = self
.archetype
.edges()
.get_add_bundle(self.bundle_info.id)
.unwrap();
self.bundle_info.write_components(
self.table,
self.sparse_sets,
add_bundle,
entity,
self.archetype.entity_table_row(archetype_index),
self.change_tick,
bundle,
);
location
}
InsertBundleResult::NewArchetypeSameTable { new_archetype } => {
let result = self.archetype.swap_remove(location.index);
if let Some(swapped_entity) = result.swapped_entity {
self.entities.meta[swapped_entity.id as usize].location = location;
}
let new_location = new_archetype.allocate(entity, result.table_row);
self.entities.meta[entity.id as usize].location = new_location;
// PERF: this could be looked up during Inserter construction and stored (but borrowing makes this nasty)
let add_bundle = self
.archetype
.edges()
.get_add_bundle(self.bundle_info.id)
.unwrap();
self.bundle_info.write_components(
self.table,
self.sparse_sets,
add_bundle,
entity,
result.table_row,
self.change_tick,
bundle,
);
new_location
}
InsertBundleResult::NewArchetypeNewTable {
new_archetype,
new_table,
} => {
let result = self.archetype.swap_remove(location.index);
if let Some(swapped_entity) = result.swapped_entity {
self.entities.meta[swapped_entity.id as usize].location = location;
}
// PERF: store "non bundle" components in edge, then just move those to avoid
// redundant copies
let move_result = self
.table
.move_to_superset_unchecked(result.table_row, *new_table);
let new_location = new_archetype.allocate(entity, move_result.new_row);
self.entities.meta[entity.id as usize].location = new_location;
// if an entity was moved into this entity's table spot, update its table row
if let Some(swapped_entity) = move_result.swapped_entity {
let swapped_location = self.entities.get(swapped_entity).unwrap();
let swapped_archetype = if self.archetype.id() == swapped_location.archetype_id
{
&mut *self.archetype
} else if new_archetype.id() == swapped_location.archetype_id {
new_archetype
} else {
// SAFETY: the only two borrowed archetypes are above and we just did collision checks
&mut *self
.archetypes_ptr
.add(swapped_location.archetype_id.index())
};
swapped_archetype
.set_entity_table_row(swapped_location.index, result.table_row);
}
// PERF: this could be looked up during Inserter construction and stored (but borrowing makes this nasty)
let add_bundle = self
.archetype
.edges()
.get_add_bundle(self.bundle_info.id)
.unwrap();
self.bundle_info.write_components(
new_table,
self.sparse_sets,
add_bundle,
entity,
move_result.new_row,
self.change_tick,
bundle,
);
new_location
}
}
}
}
pub(crate) struct BundleSpawner<'a, 'b> {
pub(crate) archetype: &'a mut Archetype,
pub(crate) entities: &'a mut Entities,
add_bundle: &'a AddBundle,
bundle_info: &'b BundleInfo,
table: &'a mut Table,
sparse_sets: &'a mut SparseSets,
change_tick: u32,
}
impl<'a, 'b> BundleSpawner<'a, 'b> {
pub fn reserve_storage(&mut self, additional: usize) {
self.archetype.reserve(additional);
self.table.reserve(additional);
}
/// # Safety
/// `entity` must be allocated (but non-existent), `T` must match this [`BundleInfo`]'s type
#[inline]
pub unsafe fn spawn_non_existent<T: Bundle>(
&mut self,
entity: Entity,
bundle: T,
) -> EntityLocation {
let table_row = self.table.allocate(entity);
let location = self.archetype.allocate(entity, table_row);
self.bundle_info.write_components(
self.table,
self.sparse_sets,
self.add_bundle,
entity,
table_row,
self.change_tick,
bundle,
);
self.entities.meta[entity.id as usize].location = location;
location
}
/// # Safety
/// `T` must match this [`BundleInfo`]'s type
#[inline]
pub unsafe fn spawn<T: Bundle>(&mut self, bundle: T) -> Entity {
let entity = self.entities.alloc();
// SAFETY: entity is allocated (but non-existent), `T` matches this BundleInfo's type
self.spawn_non_existent(entity, bundle);
entity
}
}
#[derive(Default)]
pub struct Bundles {
bundle_infos: Vec<BundleInfo>,
bundle_ids: HashMap<TypeId, BundleId>,
}
impl Bundles {
#[inline]
pub fn get(&self, bundle_id: BundleId) -> Option<&BundleInfo> {
self.bundle_infos.get(bundle_id.index())
}
#[inline]
pub fn get_id(&self, type_id: TypeId) -> Option<BundleId> {
self.bundle_ids.get(&type_id).cloned()
}
pub(crate) fn init_info<'a, T: Bundle>(
&'a mut self,
components: &mut Components,
storages: &mut Storages,
) -> &'a BundleInfo {
let bundle_infos = &mut self.bundle_infos;
let id = self.bundle_ids.entry(TypeId::of::<T>()).or_insert_with(|| {
let mut component_ids = Vec::new();
T::component_ids(components, storages, &mut |id| component_ids.push(id));
let id = BundleId(bundle_infos.len());
// SAFETY: T::component_id ensures info was created
let bundle_info = unsafe {
initialize_bundle(std::any::type_name::<T>(), component_ids, id, components)
};
bundle_infos.push(bundle_info);
id
});
// SAFETY: index either exists, or was initialized
unsafe { self.bundle_infos.get_unchecked(id.0) }
}
}
/// # Safety
///
/// `component_id` must be valid [`ComponentId`]'s
unsafe fn initialize_bundle(
bundle_type_name: &'static str,
component_ids: Vec<ComponentId>,
id: BundleId,
components: &mut Components,
) -> BundleInfo {
let mut storage_types = Vec::new();
for &component_id in &component_ids {
// SAFETY: component_id exists and is therefore valid
let component_info = components.get_info_unchecked(component_id);
storage_types.push(component_info.storage_type());
}
let mut deduped = component_ids.clone();
deduped.sort();
deduped.dedup();
assert!(
deduped.len() == component_ids.len(),
"Bundle {} has duplicate components",
bundle_type_name
);
BundleInfo {
id,
component_ids,
storage_types,
}
}