5af2f022d8
# Rename `WorldQueryData` & `WorldQueryFilter` to `QueryData` & `QueryFilter` Fixes #10776 ## Solution Traits `WorldQueryData` & `WorldQueryFilter` were renamed to `QueryData` and `QueryFilter`, respectively. Related Trait types were also renamed. --- ## Changelog - Trait `WorldQueryData` has been renamed to `QueryData`. Derive macro's `QueryData` attribute `world_query_data` has been renamed to `query_data`. - Trait `WorldQueryFilter` has been renamed to `QueryFilter`. Derive macro's `QueryFilter` attribute `world_query_filter` has been renamed to `query_filter`. - Trait's `ExtractComponent` type `Query` has been renamed to `Data`. - Trait's `GetBatchData` types `Query` & `QueryFilter` has been renamed to `Data` & `Filter`, respectively. - Trait's `ExtractInstance` type `Query` has been renamed to `Data`. - Trait's `ViewNode` type `ViewQuery` has been renamed to `ViewData`. - Trait's `RenderCommand` types `ViewWorldQuery` & `ItemWorldQuery` has been renamed to `ViewData` & `ItemData`, respectively. ## Migration Guide Note: if merged before 0.13 is released, this should instead modify the migration guide of #10776 with the updated names. - Rename `WorldQueryData` & `WorldQueryFilter` trait usages to `QueryData` & `QueryFilter` and their respective derive macro attributes `world_query_data` & `world_query_filter` to `query_data` & `query_filter`. - Rename the following trait type usages: - Trait's `ExtractComponent` type `Query` to `Data`. - Trait's `GetBatchData` type `Query` to `Data`. - Trait's `ExtractInstance` type `Query` to `Data`. - Trait's `ViewNode` type `ViewQuery` to `ViewData`' - Trait's `RenderCommand` types `ViewWolrdQuery` & `ItemWorldQuery` to `ViewData` & `ItemData`, respectively. ```rust // Before #[derive(WorldQueryData)] #[world_query_data(derive(Debug))] struct EmptyQuery { empty: (), } // After #[derive(QueryData)] #[query_data(derive(Debug))] struct EmptyQuery { empty: (), } // Before #[derive(WorldQueryFilter)] struct CustomQueryFilter<T: Component, P: Component> { _c: With<ComponentC>, _d: With<ComponentD>, _or: Or<(Added<ComponentC>, Changed<ComponentD>, Without<ComponentZ>)>, _generic_tuple: (With<T>, With<P>), } // After #[derive(QueryFilter)] struct CustomQueryFilter<T: Component, P: Component> { _c: With<ComponentC>, _d: With<ComponentD>, _or: Or<(Added<ComponentC>, Changed<ComponentD>, Without<ComponentZ>)>, _generic_tuple: (With<T>, With<P>), } // Before impl ExtractComponent for ContrastAdaptiveSharpeningSettings { type Query = &'static Self; type Filter = With<Camera>; type Out = (DenoiseCAS, CASUniform); fn extract_component(item: QueryItem<Self::Query>) -> Option<Self::Out> { //... } } // After impl ExtractComponent for ContrastAdaptiveSharpeningSettings { type Data = &'static Self; type Filter = With<Camera>; type Out = (DenoiseCAS, CASUniform); fn extract_component(item: QueryItem<Self::Data>) -> Option<Self::Out> { //... } } // Before impl GetBatchData for MeshPipeline { type Param = SRes<RenderMeshInstances>; type Query = Entity; type QueryFilter = With<Mesh3d>; type CompareData = (MaterialBindGroupId, AssetId<Mesh>); type BufferData = MeshUniform; fn get_batch_data( mesh_instances: &SystemParamItem<Self::Param>, entity: &QueryItem<Self::Query>, ) -> (Self::BufferData, Option<Self::CompareData>) { // .... } } // After impl GetBatchData for MeshPipeline { type Param = SRes<RenderMeshInstances>; type Data = Entity; type Filter = With<Mesh3d>; type CompareData = (MaterialBindGroupId, AssetId<Mesh>); type BufferData = MeshUniform; fn get_batch_data( mesh_instances: &SystemParamItem<Self::Param>, entity: &QueryItem<Self::Data>, ) -> (Self::BufferData, Option<Self::CompareData>) { // .... } } // Before impl<A> ExtractInstance for AssetId<A> where A: Asset, { type Query = Read<Handle<A>>; type Filter = (); fn extract(item: QueryItem<'_, Self::Query>) -> Option<Self> { Some(item.id()) } } // After impl<A> ExtractInstance for AssetId<A> where A: Asset, { type Data = Read<Handle<A>>; type Filter = (); fn extract(item: QueryItem<'_, Self::Data>) -> Option<Self> { Some(item.id()) } } // Before impl ViewNode for PostProcessNode { type ViewQuery = ( &'static ViewTarget, &'static PostProcessSettings, ); fn run( &self, _graph: &mut RenderGraphContext, render_context: &mut RenderContext, (view_target, _post_process_settings): QueryItem<Self::ViewQuery>, world: &World, ) -> Result<(), NodeRunError> { // ... } } // After impl ViewNode for PostProcessNode { type ViewData = ( &'static ViewTarget, &'static PostProcessSettings, ); fn run( &self, _graph: &mut RenderGraphContext, render_context: &mut RenderContext, (view_target, _post_process_settings): QueryItem<Self::ViewData>, world: &World, ) -> Result<(), NodeRunError> { // ... } } // Before impl<P: CachedRenderPipelinePhaseItem> RenderCommand<P> for SetItemPipeline { type Param = SRes<PipelineCache>; type ViewWorldQuery = (); type ItemWorldQuery = (); #[inline] fn render<'w>( item: &P, _view: (), _entity: (), pipeline_cache: SystemParamItem<'w, '_, Self::Param>, pass: &mut TrackedRenderPass<'w>, ) -> RenderCommandResult { // ... } } // After impl<P: CachedRenderPipelinePhaseItem> RenderCommand<P> for SetItemPipeline { type Param = SRes<PipelineCache>; type ViewData = (); type ItemData = (); #[inline] fn render<'w>( item: &P, _view: (), _entity: (), pipeline_cache: SystemParamItem<'w, '_, Self::Param>, pass: &mut TrackedRenderPass<'w>, ) -> RenderCommandResult { // ... } } ```
843 lines
32 KiB
Rust
843 lines
32 KiB
Rust
use crate::{
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archetype::{Archetype, ArchetypeEntity, ArchetypeId, Archetypes},
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component::Tick,
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entity::{Entities, Entity},
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query::{ArchetypeFilter, DebugCheckedUnwrap, QueryState},
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storage::{Table, TableId, TableRow, Tables},
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world::unsafe_world_cell::UnsafeWorldCell,
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};
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use std::{borrow::Borrow, iter::FusedIterator, mem::MaybeUninit, ops::Range};
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use super::{QueryData, QueryFilter, ReadOnlyQueryData};
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/// An [`Iterator`] over query results of a [`Query`](crate::system::Query).
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///
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/// This struct is created by the [`Query::iter`](crate::system::Query::iter) and
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/// [`Query::iter_mut`](crate::system::Query::iter_mut) methods.
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pub struct QueryIter<'w, 's, Q: QueryData, F: QueryFilter> {
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tables: &'w Tables,
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archetypes: &'w Archetypes,
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query_state: &'s QueryState<Q, F>,
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cursor: QueryIterationCursor<'w, 's, Q, F>,
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}
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impl<'w, 's, Q: QueryData, F: QueryFilter> QueryIter<'w, 's, Q, F> {
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/// # Safety
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/// - `world` must have permission to access any of the components registered in `query_state`.
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/// - `world` must be the same one used to initialize `query_state`.
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pub(crate) unsafe fn new(
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world: UnsafeWorldCell<'w>,
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query_state: &'s QueryState<Q, F>,
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last_run: Tick,
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this_run: Tick,
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) -> Self {
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QueryIter {
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query_state,
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// SAFETY: We only access table data that has been registered in `query_state`.
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tables: &world.storages().tables,
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archetypes: world.archetypes(),
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cursor: QueryIterationCursor::init(world, query_state, last_run, this_run),
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}
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}
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/// Executes the equivalent of [`Iterator::for_each`] over a contiguous segment
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/// from an table.
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///
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/// # Safety
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/// - all `rows` must be in `[0, table.entity_count)`.
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/// - `table` must match Q and F
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/// - Both `Q::IS_DENSE` and `F::IS_DENSE` must be true.
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#[inline]
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#[cfg(all(not(target = "wasm32"), feature = "multi-threaded"))]
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pub(super) unsafe fn for_each_in_table_range<Func>(
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&mut self,
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func: &mut Func,
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table: &'w Table,
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rows: Range<usize>,
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) where
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Func: FnMut(Q::Item<'w>),
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{
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// SAFETY: Caller assures that Q::IS_DENSE and F::IS_DENSE are true, that table matches Q and F
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// and all indicies in rows are in range.
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unsafe {
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self.fold_over_table_range((), &mut |_, item| func(item), table, rows);
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}
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}
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/// Executes the equivalent of [`Iterator::for_each`] over a contiguous segment
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/// from an archetype.
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///
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/// # Safety
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/// - all `indices` must be in `[0, archetype.len())`.
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/// - `archetype` must match Q and F
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/// - Either `Q::IS_DENSE` or `F::IS_DENSE` must be false.
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#[inline]
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#[cfg(all(not(target = "wasm32"), feature = "multi-threaded"))]
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pub(super) unsafe fn for_each_in_archetype_range<Func>(
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&mut self,
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func: &mut Func,
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archetype: &'w Archetype,
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rows: Range<usize>,
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) where
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Func: FnMut(Q::Item<'w>),
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{
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// SAFETY: Caller assures that either Q::IS_DENSE or F::IS_DENSE are false, that archetype matches Q and F
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// and all indices in rows are in range.
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unsafe {
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self.fold_over_archetype_range((), &mut |_, item| func(item), archetype, rows);
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}
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}
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/// Executes the equivalent of [`Iterator::fold`] over a contiguous segment
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/// from an table.
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///
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/// # Safety
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/// - all `rows` must be in `[0, table.entity_count)`.
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/// - `table` must match Q and F
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/// - Both `Q::IS_DENSE` and `F::IS_DENSE` must be true.
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#[inline]
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pub(super) unsafe fn fold_over_table_range<B, Func>(
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&mut self,
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mut accum: B,
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func: &mut Func,
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table: &'w Table,
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rows: Range<usize>,
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) -> B
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where
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Func: FnMut(B, Q::Item<'w>) -> B,
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{
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assert!(
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rows.end <= u32::MAX as usize,
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"TableRow is only valid up to u32::MAX"
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);
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Q::set_table(&mut self.cursor.fetch, &self.query_state.fetch_state, table);
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F::set_table(
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&mut self.cursor.filter,
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&self.query_state.filter_state,
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table,
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);
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let entities = table.entities();
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for row in rows {
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// SAFETY: Caller assures `row` in range of the current archetype.
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let entity = entities.get_unchecked(row);
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let row = TableRow::from_usize(row);
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// SAFETY: set_table was called prior.
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// Caller assures `row` in range of the current archetype.
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if !F::filter_fetch(&mut self.cursor.filter, *entity, row) {
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continue;
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}
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// SAFETY: set_table was called prior.
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// Caller assures `row` in range of the current archetype.
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let item = Q::fetch(&mut self.cursor.fetch, *entity, row);
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accum = func(accum, item);
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}
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accum
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}
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/// Executes the equivalent of [`Iterator::fold`] over a contiguous segment
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/// from an archetype.
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///
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/// # Safety
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/// - all `indices` must be in `[0, archetype.len())`.
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/// - `archetype` must match Q and F
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/// - Either `Q::IS_DENSE` or `F::IS_DENSE` must be false.
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#[inline]
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pub(super) unsafe fn fold_over_archetype_range<B, Func>(
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&mut self,
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mut accum: B,
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func: &mut Func,
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archetype: &'w Archetype,
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indices: Range<usize>,
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) -> B
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where
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Func: FnMut(B, Q::Item<'w>) -> B,
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{
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let table = self.tables.get(archetype.table_id()).debug_checked_unwrap();
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Q::set_archetype(
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&mut self.cursor.fetch,
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&self.query_state.fetch_state,
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archetype,
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table,
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);
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F::set_archetype(
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&mut self.cursor.filter,
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&self.query_state.filter_state,
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archetype,
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table,
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);
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let entities = archetype.entities();
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for index in indices {
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// SAFETY: Caller assures `index` in range of the current archetype.
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let archetype_entity = entities.get_unchecked(index);
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// SAFETY: set_archetype was called prior.
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// Caller assures `index` in range of the current archetype.
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if !F::filter_fetch(
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&mut self.cursor.filter,
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archetype_entity.entity(),
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archetype_entity.table_row(),
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) {
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continue;
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}
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// SAFETY: set_archetype was called prior, `index` is an archetype index in range of the current archetype
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// Caller assures `index` in range of the current archetype.
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let item = Q::fetch(
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&mut self.cursor.fetch,
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archetype_entity.entity(),
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archetype_entity.table_row(),
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);
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accum = func(accum, item);
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}
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accum
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}
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}
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impl<'w, 's, Q: QueryData, F: QueryFilter> Iterator for QueryIter<'w, 's, Q, F> {
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type Item = Q::Item<'w>;
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#[inline(always)]
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fn next(&mut self) -> Option<Self::Item> {
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// SAFETY:
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// `tables` and `archetypes` belong to the same world that the cursor was initialized for.
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// `query_state` is the state that was passed to `QueryIterationCursor::init`.
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unsafe {
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self.cursor
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.next(self.tables, self.archetypes, self.query_state)
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}
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}
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fn size_hint(&self) -> (usize, Option<usize>) {
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let max_size = self.cursor.max_remaining(self.tables, self.archetypes);
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let archetype_query = F::IS_ARCHETYPAL;
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let min_size = if archetype_query { max_size } else { 0 };
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(min_size, Some(max_size))
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}
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#[inline]
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fn fold<B, Func>(mut self, init: B, mut func: Func) -> B
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where
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Func: FnMut(B, Self::Item) -> B,
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{
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let mut accum = init;
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// Empty any remaining uniterated values from the current table/archetype
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while self.cursor.current_row != self.cursor.current_len {
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let Some(item) = self.next() else { break };
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accum = func(accum, item);
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}
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if Q::IS_DENSE && F::IS_DENSE {
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for table_id in self.cursor.table_id_iter.clone() {
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// SAFETY: Matched table IDs are guaranteed to still exist.
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let table = unsafe { self.tables.get(*table_id).debug_checked_unwrap() };
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accum =
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// SAFETY:
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// - The fetched table matches both Q and F
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// - The provided range is equivalent to [0, table.entity_count)
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// - The if block ensures that Q::IS_DENSE and F::IS_DENSE are both true
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unsafe { self.fold_over_table_range(accum, &mut func, table, 0..table.entity_count()) };
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}
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} else {
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for archetype_id in self.cursor.archetype_id_iter.clone() {
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let archetype =
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// SAFETY: Matched archetype IDs are guaranteed to still exist.
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unsafe { self.archetypes.get(*archetype_id).debug_checked_unwrap() };
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accum =
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// SAFETY:
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// - The fetched archetype matches both Q and F
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// - The provided range is equivalent to [0, archetype.len)
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// - The if block ensures that ether Q::IS_DENSE or F::IS_DENSE are false
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unsafe { self.fold_over_archetype_range(accum, &mut func, archetype, 0..archetype.len()) };
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}
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}
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accum
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}
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}
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// This is correct as [`QueryIter`] always returns `None` once exhausted.
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impl<'w, 's, Q: QueryData, F: QueryFilter> FusedIterator for QueryIter<'w, 's, Q, F> {}
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/// An [`Iterator`] over the query items generated from an iterator of [`Entity`]s.
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///
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/// Items are returned in the order of the provided iterator.
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/// Entities that don't match the query are skipped.
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///
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/// This struct is created by the [`Query::iter_many`](crate::system::Query::iter_many) and [`Query::iter_many_mut`](crate::system::Query::iter_many_mut) methods.
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pub struct QueryManyIter<'w, 's, Q: QueryData, F: QueryFilter, I: Iterator>
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where
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I::Item: Borrow<Entity>,
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{
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entity_iter: I,
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entities: &'w Entities,
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tables: &'w Tables,
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archetypes: &'w Archetypes,
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fetch: Q::Fetch<'w>,
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filter: F::Fetch<'w>,
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query_state: &'s QueryState<Q, F>,
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}
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impl<'w, 's, Q: QueryData, F: QueryFilter, I: Iterator> QueryManyIter<'w, 's, Q, F, I>
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where
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I::Item: Borrow<Entity>,
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{
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/// # Safety
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/// - `world` must have permission to access any of the components registered in `query_state`.
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/// - `world` must be the same one used to initialize `query_state`.
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pub(crate) unsafe fn new<EntityList: IntoIterator<IntoIter = I>>(
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world: UnsafeWorldCell<'w>,
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query_state: &'s QueryState<Q, F>,
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entity_list: EntityList,
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last_run: Tick,
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this_run: Tick,
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) -> QueryManyIter<'w, 's, Q, F, I> {
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let fetch = Q::init_fetch(world, &query_state.fetch_state, last_run, this_run);
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let filter = F::init_fetch(world, &query_state.filter_state, last_run, this_run);
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QueryManyIter {
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query_state,
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entities: world.entities(),
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archetypes: world.archetypes(),
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// SAFETY: We only access table data that has been registered in `query_state`.
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// This means `world` has permission to access the data we use.
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tables: &world.storages().tables,
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fetch,
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filter,
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entity_iter: entity_list.into_iter(),
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}
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}
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/// Safety:
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/// The lifetime here is not restrictive enough for Fetch with &mut access,
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/// as calling `fetch_next_aliased_unchecked` multiple times can produce multiple
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/// references to the same component, leading to unique reference aliasing.
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///
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/// It is always safe for shared access.
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#[inline(always)]
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unsafe fn fetch_next_aliased_unchecked(&mut self) -> Option<Q::Item<'w>> {
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for entity in self.entity_iter.by_ref() {
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let entity = *entity.borrow();
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let Some(location) = self.entities.get(entity) else {
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continue;
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};
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if !self
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.query_state
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.matched_archetypes
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.contains(location.archetype_id.index())
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{
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continue;
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}
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let archetype = self
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.archetypes
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.get(location.archetype_id)
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.debug_checked_unwrap();
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let table = self.tables.get(location.table_id).debug_checked_unwrap();
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// SAFETY: `archetype` is from the world that `fetch/filter` were created for,
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// `fetch_state`/`filter_state` are the states that `fetch/filter` were initialized with
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Q::set_archetype(
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&mut self.fetch,
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&self.query_state.fetch_state,
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archetype,
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table,
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);
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// SAFETY: `table` is from the world that `fetch/filter` were created for,
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// `fetch_state`/`filter_state` are the states that `fetch/filter` were initialized with
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F::set_archetype(
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&mut self.filter,
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&self.query_state.filter_state,
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archetype,
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table,
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);
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// SAFETY: set_archetype was called prior.
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// `location.archetype_row` is an archetype index row in range of the current archetype, because if it was not, the match above would have `continue`d
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if F::filter_fetch(&mut self.filter, entity, location.table_row) {
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// SAFETY:
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// - set_archetype was called prior, `location.archetype_row` is an archetype index in range of the current archetype
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// - fetch is only called once for each entity.
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return Some(Q::fetch(&mut self.fetch, entity, location.table_row));
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}
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}
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None
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}
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/// Get next result from the query
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#[inline(always)]
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pub fn fetch_next(&mut self) -> Option<Q::Item<'_>> {
|
|
// SAFETY: we are limiting the returned reference to self,
|
|
// making sure this method cannot be called multiple times without getting rid
|
|
// of any previously returned unique references first, thus preventing aliasing.
|
|
unsafe { self.fetch_next_aliased_unchecked().map(Q::shrink) }
|
|
}
|
|
}
|
|
|
|
impl<'w, 's, Q: ReadOnlyQueryData, F: QueryFilter, I: Iterator> Iterator
|
|
for QueryManyIter<'w, 's, Q, F, I>
|
|
where
|
|
I::Item: Borrow<Entity>,
|
|
{
|
|
type Item = Q::Item<'w>;
|
|
|
|
#[inline(always)]
|
|
fn next(&mut self) -> Option<Self::Item> {
|
|
// SAFETY: It is safe to alias for ReadOnlyWorldQuery.
|
|
unsafe { self.fetch_next_aliased_unchecked() }
|
|
}
|
|
|
|
fn size_hint(&self) -> (usize, Option<usize>) {
|
|
let (_, max_size) = self.entity_iter.size_hint();
|
|
(0, max_size)
|
|
}
|
|
}
|
|
|
|
// This is correct as [`QueryManyIter`] always returns `None` once exhausted.
|
|
impl<'w, 's, Q: ReadOnlyQueryData, F: QueryFilter, I: Iterator> FusedIterator
|
|
for QueryManyIter<'w, 's, Q, F, I>
|
|
where
|
|
I::Item: Borrow<Entity>,
|
|
{
|
|
}
|
|
|
|
/// An iterator over `K`-sized combinations of query items without repetition.
|
|
///
|
|
/// A combination is an arrangement of a collection of items where order does not matter.
|
|
///
|
|
/// `K` is the number of items that make up each subset, and the number of items returned by the iterator.
|
|
/// `N` is the number of total entities output by the query.
|
|
///
|
|
/// For example, given the list [1, 2, 3, 4], where `K` is 2, the combinations without repeats are
|
|
/// [1, 2], [1, 3], [1, 4], [2, 3], [2, 4], [3, 4].
|
|
/// And in this case, `N` would be defined as 4 since the size of the input list is 4.
|
|
///
|
|
/// The number of combinations depend on how `K` relates to the number of entities matching the [`Query`]:
|
|
/// - if `K = N`, only one combination exists,
|
|
/// - if `K < N`, there are <sub>N</sub>C<sub>K</sub> combinations (see the [performance section] of `Query`),
|
|
/// - if `K > N`, there are no combinations.
|
|
///
|
|
/// The output combination is not guaranteed to have any order of iteration.
|
|
///
|
|
/// # Usage
|
|
///
|
|
/// This type is returned by calling [`Query::iter_combinations`] or [`Query::iter_combinations_mut`].
|
|
///
|
|
/// It implements [`Iterator`] only if it iterates over read-only query items ([learn more]).
|
|
///
|
|
/// In the case of mutable query items, it can be iterated by calling [`fetch_next`] in a `while let` loop.
|
|
///
|
|
/// # Examples
|
|
///
|
|
/// The following example shows how to traverse the iterator when the query items are read-only.
|
|
///
|
|
/// ```
|
|
/// # use bevy_ecs::prelude::*;
|
|
/// # #[derive(Component)]
|
|
/// # struct ComponentA;
|
|
/// #
|
|
/// fn some_system(query: Query<&ComponentA>) {
|
|
/// for [a1, a2] in query.iter_combinations() {
|
|
/// // ...
|
|
/// }
|
|
/// }
|
|
/// ```
|
|
///
|
|
/// The following example shows how `fetch_next` should be called with a `while let` loop to traverse the iterator when the query items are mutable.
|
|
///
|
|
/// ```
|
|
/// # use bevy_ecs::prelude::*;
|
|
/// # #[derive(Component)]
|
|
/// # struct ComponentA;
|
|
/// #
|
|
/// fn some_system(mut query: Query<&mut ComponentA>) {
|
|
/// let mut combinations = query.iter_combinations_mut();
|
|
/// while let Some([a1, a2]) = combinations.fetch_next() {
|
|
/// // ...
|
|
/// }
|
|
/// }
|
|
/// ```
|
|
///
|
|
/// [`fetch_next`]: Self::fetch_next
|
|
/// [learn more]: Self#impl-Iterator
|
|
/// [performance section]: crate::system::Query#performance
|
|
/// [`Query`]: crate::system::Query
|
|
/// [`Query::iter_combinations`]: crate::system::Query::iter_combinations
|
|
/// [`Query::iter_combinations_mut`]: crate::system::Query::iter_combinations_mut
|
|
pub struct QueryCombinationIter<'w, 's, Q: QueryData, F: QueryFilter, const K: usize> {
|
|
tables: &'w Tables,
|
|
archetypes: &'w Archetypes,
|
|
query_state: &'s QueryState<Q, F>,
|
|
cursors: [QueryIterationCursor<'w, 's, Q, F>; K],
|
|
}
|
|
|
|
impl<'w, 's, Q: QueryData, F: QueryFilter, const K: usize> QueryCombinationIter<'w, 's, Q, F, K> {
|
|
/// # Safety
|
|
/// - `world` must have permission to access any of the components registered in `query_state`.
|
|
/// - `world` must be the same one used to initialize `query_state`.
|
|
pub(crate) unsafe fn new(
|
|
world: UnsafeWorldCell<'w>,
|
|
query_state: &'s QueryState<Q, F>,
|
|
last_run: Tick,
|
|
this_run: Tick,
|
|
) -> Self {
|
|
// Initialize array with cursors.
|
|
// There is no FromIterator on arrays, so instead initialize it manually with MaybeUninit
|
|
|
|
let mut array: MaybeUninit<[QueryIterationCursor<'w, 's, Q, F>; K]> = MaybeUninit::uninit();
|
|
let ptr = array
|
|
.as_mut_ptr()
|
|
.cast::<QueryIterationCursor<'w, 's, Q, F>>();
|
|
if K != 0 {
|
|
ptr.write(QueryIterationCursor::init(
|
|
world,
|
|
query_state,
|
|
last_run,
|
|
this_run,
|
|
));
|
|
}
|
|
for slot in (1..K).map(|offset| ptr.add(offset)) {
|
|
slot.write(QueryIterationCursor::init_empty(
|
|
world,
|
|
query_state,
|
|
last_run,
|
|
this_run,
|
|
));
|
|
}
|
|
|
|
QueryCombinationIter {
|
|
query_state,
|
|
// SAFETY: We only access table data that has been registered in `query_state`.
|
|
tables: &world.storages().tables,
|
|
archetypes: world.archetypes(),
|
|
cursors: array.assume_init(),
|
|
}
|
|
}
|
|
|
|
/// Safety:
|
|
/// The lifetime here is not restrictive enough for Fetch with &mut access,
|
|
/// as calling `fetch_next_aliased_unchecked` multiple times can produce multiple
|
|
/// references to the same component, leading to unique reference aliasing.
|
|
///.
|
|
/// It is always safe for shared access.
|
|
unsafe fn fetch_next_aliased_unchecked(&mut self) -> Option<[Q::Item<'w>; K]> {
|
|
if K == 0 {
|
|
return None;
|
|
}
|
|
|
|
// PERF: can speed up the following code using `cursor.remaining()` instead of `next_item.is_none()`
|
|
// when Q::IS_ARCHETYPAL && F::IS_ARCHETYPAL
|
|
//
|
|
// let `i` be the index of `c`, the last cursor in `self.cursors` that
|
|
// returns `K-i` or more elements.
|
|
// Make cursor in index `j` for all `j` in `[i, K)` a copy of `c` advanced `j-i+1` times.
|
|
// If no such `c` exists, return `None`
|
|
'outer: for i in (0..K).rev() {
|
|
match self.cursors[i].next(self.tables, self.archetypes, self.query_state) {
|
|
Some(_) => {
|
|
for j in (i + 1)..K {
|
|
self.cursors[j] = self.cursors[j - 1].clone();
|
|
match self.cursors[j].next(self.tables, self.archetypes, self.query_state) {
|
|
Some(_) => {}
|
|
None if i > 0 => continue 'outer,
|
|
None => return None,
|
|
}
|
|
}
|
|
break;
|
|
}
|
|
None if i > 0 => continue,
|
|
None => return None,
|
|
}
|
|
}
|
|
|
|
let mut values = MaybeUninit::<[Q::Item<'w>; K]>::uninit();
|
|
|
|
let ptr = values.as_mut_ptr().cast::<Q::Item<'w>>();
|
|
for (offset, cursor) in self.cursors.iter_mut().enumerate() {
|
|
ptr.add(offset).write(cursor.peek_last().unwrap());
|
|
}
|
|
|
|
Some(values.assume_init())
|
|
}
|
|
|
|
/// Get next combination of queried components
|
|
#[inline]
|
|
pub fn fetch_next(&mut self) -> Option<[Q::Item<'_>; K]> {
|
|
// SAFETY: we are limiting the returned reference to self,
|
|
// making sure this method cannot be called multiple times without getting rid
|
|
// of any previously returned unique references first, thus preventing aliasing.
|
|
unsafe {
|
|
self.fetch_next_aliased_unchecked()
|
|
.map(|array| array.map(Q::shrink))
|
|
}
|
|
}
|
|
}
|
|
|
|
// Iterator type is intentionally implemented only for read-only access.
|
|
// Doing so for mutable references would be unsound, because calling `next`
|
|
// multiple times would allow multiple owned references to the same data to exist.
|
|
impl<'w, 's, Q: ReadOnlyQueryData, F: QueryFilter, const K: usize> Iterator
|
|
for QueryCombinationIter<'w, 's, Q, F, K>
|
|
{
|
|
type Item = [Q::Item<'w>; K];
|
|
|
|
#[inline]
|
|
fn next(&mut self) -> Option<Self::Item> {
|
|
// Safety: it is safe to alias for ReadOnlyWorldQuery
|
|
unsafe { QueryCombinationIter::fetch_next_aliased_unchecked(self) }
|
|
}
|
|
|
|
fn size_hint(&self) -> (usize, Option<usize>) {
|
|
// binomial coefficient: (n ; k) = n! / k!(n-k)! = (n*n-1*...*n-k+1) / k!
|
|
// See https://en.wikipedia.org/wiki/Binomial_coefficient
|
|
// See https://blog.plover.com/math/choose.html for implementation
|
|
// It was chosen to reduce overflow potential.
|
|
fn choose(n: usize, k: usize) -> Option<usize> {
|
|
if k > n || n == 0 {
|
|
return Some(0);
|
|
}
|
|
let k = k.min(n - k);
|
|
let ks = 1..=k;
|
|
let ns = (n - k + 1..=n).rev();
|
|
ks.zip(ns)
|
|
.try_fold(1_usize, |acc, (k, n)| Some(acc.checked_mul(n)? / k))
|
|
}
|
|
// sum_i=0..k choose(cursors[i].remaining, k-i)
|
|
let max_combinations = self
|
|
.cursors
|
|
.iter()
|
|
.enumerate()
|
|
.try_fold(0, |acc, (i, cursor)| {
|
|
let n = cursor.max_remaining(self.tables, self.archetypes);
|
|
Some(acc + choose(n, K - i)?)
|
|
});
|
|
|
|
let archetype_query = F::IS_ARCHETYPAL;
|
|
let known_max = max_combinations.unwrap_or(usize::MAX);
|
|
let min_combinations = if archetype_query { known_max } else { 0 };
|
|
(min_combinations, max_combinations)
|
|
}
|
|
}
|
|
|
|
impl<'w, 's, Q: QueryData, F: QueryFilter> ExactSizeIterator for QueryIter<'w, 's, Q, F>
|
|
where
|
|
F: ArchetypeFilter,
|
|
{
|
|
fn len(&self) -> usize {
|
|
self.size_hint().0
|
|
}
|
|
}
|
|
|
|
// This is correct as [`QueryCombinationIter`] always returns `None` once exhausted.
|
|
impl<'w, 's, Q: ReadOnlyQueryData, F: QueryFilter, const K: usize> FusedIterator
|
|
for QueryCombinationIter<'w, 's, Q, F, K>
|
|
{
|
|
}
|
|
|
|
struct QueryIterationCursor<'w, 's, Q: QueryData, F: QueryFilter> {
|
|
table_id_iter: std::slice::Iter<'s, TableId>,
|
|
archetype_id_iter: std::slice::Iter<'s, ArchetypeId>,
|
|
table_entities: &'w [Entity],
|
|
archetype_entities: &'w [ArchetypeEntity],
|
|
fetch: Q::Fetch<'w>,
|
|
filter: F::Fetch<'w>,
|
|
// length of the table table or length of the archetype, depending on whether both `Q`'s and `F`'s fetches are dense
|
|
current_len: usize,
|
|
// either table row or archetype index, depending on whether both `Q`'s and `F`'s fetches are dense
|
|
current_row: usize,
|
|
}
|
|
|
|
impl<Q: QueryData, F: QueryFilter> Clone for QueryIterationCursor<'_, '_, Q, F> {
|
|
fn clone(&self) -> Self {
|
|
Self {
|
|
table_id_iter: self.table_id_iter.clone(),
|
|
archetype_id_iter: self.archetype_id_iter.clone(),
|
|
table_entities: self.table_entities,
|
|
archetype_entities: self.archetype_entities,
|
|
fetch: self.fetch.clone(),
|
|
filter: self.filter.clone(),
|
|
current_len: self.current_len,
|
|
current_row: self.current_row,
|
|
}
|
|
}
|
|
}
|
|
|
|
impl<'w, 's, Q: QueryData, F: QueryFilter> QueryIterationCursor<'w, 's, Q, F> {
|
|
const IS_DENSE: bool = Q::IS_DENSE && F::IS_DENSE;
|
|
|
|
unsafe fn init_empty(
|
|
world: UnsafeWorldCell<'w>,
|
|
query_state: &'s QueryState<Q, F>,
|
|
last_run: Tick,
|
|
this_run: Tick,
|
|
) -> Self {
|
|
QueryIterationCursor {
|
|
table_id_iter: [].iter(),
|
|
archetype_id_iter: [].iter(),
|
|
..Self::init(world, query_state, last_run, this_run)
|
|
}
|
|
}
|
|
|
|
/// # Safety
|
|
/// - `world` must have permission to access any of the components registered in `query_state`.
|
|
/// - `world` must be the same one used to initialize `query_state`.
|
|
unsafe fn init(
|
|
world: UnsafeWorldCell<'w>,
|
|
query_state: &'s QueryState<Q, F>,
|
|
last_run: Tick,
|
|
this_run: Tick,
|
|
) -> Self {
|
|
let fetch = Q::init_fetch(world, &query_state.fetch_state, last_run, this_run);
|
|
let filter = F::init_fetch(world, &query_state.filter_state, last_run, this_run);
|
|
QueryIterationCursor {
|
|
fetch,
|
|
filter,
|
|
table_entities: &[],
|
|
archetype_entities: &[],
|
|
table_id_iter: query_state.matched_table_ids.iter(),
|
|
archetype_id_iter: query_state.matched_archetype_ids.iter(),
|
|
current_len: 0,
|
|
current_row: 0,
|
|
}
|
|
}
|
|
|
|
/// retrieve item returned from most recent `next` call again.
|
|
#[inline]
|
|
unsafe fn peek_last(&mut self) -> Option<Q::Item<'w>> {
|
|
if self.current_row > 0 {
|
|
let index = self.current_row - 1;
|
|
if Self::IS_DENSE {
|
|
let entity = self.table_entities.get_unchecked(index);
|
|
Some(Q::fetch(
|
|
&mut self.fetch,
|
|
*entity,
|
|
TableRow::from_usize(index),
|
|
))
|
|
} else {
|
|
let archetype_entity = self.archetype_entities.get_unchecked(index);
|
|
Some(Q::fetch(
|
|
&mut self.fetch,
|
|
archetype_entity.entity(),
|
|
archetype_entity.table_row(),
|
|
))
|
|
}
|
|
} else {
|
|
None
|
|
}
|
|
}
|
|
|
|
/// How many values will this cursor return at most?
|
|
///
|
|
/// Note that if `Q::IS_ARCHETYPAL && F::IS_ARCHETYPAL`, the return value
|
|
/// will be **the exact count of remaining values**.
|
|
fn max_remaining(&self, tables: &'w Tables, archetypes: &'w Archetypes) -> usize {
|
|
let remaining_matched: usize = if Self::IS_DENSE {
|
|
let ids = self.table_id_iter.clone();
|
|
ids.map(|id| tables[*id].entity_count()).sum()
|
|
} else {
|
|
let ids = self.archetype_id_iter.clone();
|
|
ids.map(|id| archetypes[*id].len()).sum()
|
|
};
|
|
remaining_matched + self.current_len - self.current_row
|
|
}
|
|
|
|
// NOTE: If you are changing query iteration code, remember to update the following places, where relevant:
|
|
// QueryIter, QueryIterationCursor, QueryManyIter, QueryCombinationIter, QueryState::par_for_each_unchecked_manual
|
|
/// # Safety
|
|
/// `tables` and `archetypes` must belong to the same world that the [`QueryIterationCursor`]
|
|
/// was initialized for.
|
|
/// `query_state` must be the same [`QueryState`] that was passed to `init` or `init_empty`.
|
|
#[inline(always)]
|
|
unsafe fn next(
|
|
&mut self,
|
|
tables: &'w Tables,
|
|
archetypes: &'w Archetypes,
|
|
query_state: &'s QueryState<Q, F>,
|
|
) -> Option<Q::Item<'w>> {
|
|
if Self::IS_DENSE {
|
|
loop {
|
|
// we are on the beginning of the query, or finished processing a table, so skip to the next
|
|
if self.current_row == self.current_len {
|
|
let table_id = self.table_id_iter.next()?;
|
|
let table = tables.get(*table_id).debug_checked_unwrap();
|
|
// SAFETY: `table` is from the world that `fetch/filter` were created for,
|
|
// `fetch_state`/`filter_state` are the states that `fetch/filter` were initialized with
|
|
Q::set_table(&mut self.fetch, &query_state.fetch_state, table);
|
|
F::set_table(&mut self.filter, &query_state.filter_state, table);
|
|
self.table_entities = table.entities();
|
|
self.current_len = table.entity_count();
|
|
self.current_row = 0;
|
|
continue;
|
|
}
|
|
|
|
// SAFETY: set_table was called prior.
|
|
// `current_row` is a table row in range of the current table, because if it was not, then the if above would have been executed.
|
|
let entity = self.table_entities.get_unchecked(self.current_row);
|
|
let row = TableRow::from_usize(self.current_row);
|
|
if !F::filter_fetch(&mut self.filter, *entity, row) {
|
|
self.current_row += 1;
|
|
continue;
|
|
}
|
|
|
|
// SAFETY:
|
|
// - set_table was called prior.
|
|
// - `current_row` must be a table row in range of the current table,
|
|
// because if it was not, then the if above would have been executed.
|
|
// - fetch is only called once for each `entity`.
|
|
let item = Q::fetch(&mut self.fetch, *entity, row);
|
|
|
|
self.current_row += 1;
|
|
return Some(item);
|
|
}
|
|
} else {
|
|
loop {
|
|
if self.current_row == self.current_len {
|
|
let archetype_id = self.archetype_id_iter.next()?;
|
|
let archetype = archetypes.get(*archetype_id).debug_checked_unwrap();
|
|
let table = tables.get(archetype.table_id()).debug_checked_unwrap();
|
|
// SAFETY: `archetype` and `tables` are from the world that `fetch/filter` were created for,
|
|
// `fetch_state`/`filter_state` are the states that `fetch/filter` were initialized with
|
|
Q::set_archetype(&mut self.fetch, &query_state.fetch_state, archetype, table);
|
|
F::set_archetype(
|
|
&mut self.filter,
|
|
&query_state.filter_state,
|
|
archetype,
|
|
table,
|
|
);
|
|
self.archetype_entities = archetype.entities();
|
|
self.current_len = archetype.len();
|
|
self.current_row = 0;
|
|
continue;
|
|
}
|
|
|
|
// SAFETY: set_archetype was called prior.
|
|
// `current_row` is an archetype index row in range of the current archetype, because if it was not, then the if above would have been executed.
|
|
let archetype_entity = self.archetype_entities.get_unchecked(self.current_row);
|
|
if !F::filter_fetch(
|
|
&mut self.filter,
|
|
archetype_entity.entity(),
|
|
archetype_entity.table_row(),
|
|
) {
|
|
self.current_row += 1;
|
|
continue;
|
|
}
|
|
|
|
// SAFETY:
|
|
// - set_archetype was called prior.
|
|
// - `current_row` must be an archetype index row in range of the current archetype,
|
|
// because if it was not, then the if above would have been executed.
|
|
// - fetch is only called once for each `archetype_entity`.
|
|
let item = Q::fetch(
|
|
&mut self.fetch,
|
|
archetype_entity.entity(),
|
|
archetype_entity.table_row(),
|
|
);
|
|
self.current_row += 1;
|
|
return Some(item);
|
|
}
|
|
}
|
|
}
|
|
}
|