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Merge 9c4fe47 into 019fa5d
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@EdvinNilsson
EdvinNilsson authored Apr 1, 2023
2 parents 019fa5d + 9c4fe47 commit 148ffb6
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Showing 3 changed files with 180 additions and 50 deletions.
16 changes: 8 additions & 8 deletions crates/ecs/src/filter.rs
View file
Original file line number Diff line number Diff line change
Expand Up @@ -45,8 +45,8 @@ impl<Component: Debug + Send + Sync + 'static + Sized> SystemParameter for With<
}))
}

fn component_access() -> Option<ComponentAccessDescriptor> {
None
fn component_accesses() -> Vec<ComponentAccessDescriptor> {
vec![]
}

fn iterates_over_entities() -> bool {
Expand Down Expand Up @@ -126,8 +126,8 @@ macro_rules! binary_filter_operation {
}))
}

fn component_access() -> Option<ComponentAccessDescriptor> {
None
fn component_accesses() -> Vec<ComponentAccessDescriptor> {
vec![]
}

fn iterates_over_entities() -> bool {
Expand Down Expand Up @@ -189,8 +189,8 @@ impl<T: Filter + SystemParameter> SystemParameter for Not<T> {
}))
}

fn component_access() -> Option<ComponentAccessDescriptor> {
None
fn component_accesses() -> Vec<ComponentAccessDescriptor> {
vec![]
}

fn iterates_over_entities() -> bool {
Expand Down Expand Up @@ -239,8 +239,8 @@ mod tests {
Some(Some(Self {}))
}

fn component_access() -> Option<ComponentAccessDescriptor> {
None
fn component_accesses() -> Vec<ComponentAccessDescriptor> {
vec![]
}

fn iterates_over_entities() -> bool {
Expand Down
44 changes: 10 additions & 34 deletions crates/ecs/src/systems/iteration.rs
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Original file line number Diff line number Diff line change
@@ -1,7 +1,7 @@
//! Different ways to iterate over all queried entities in a [`System`].
use super::*;
use crate::{intersection_of_multiple_sets, World};
use crate::World;

/// Execution of a single [`System`] in a sequential order.
pub trait SequentiallyIterable {
Expand Down Expand Up @@ -31,40 +31,16 @@ macro_rules! impl_sequentially_iterable_system {
{

fn run(&self, world: &World) -> SystemResult<()> {
let base_signature: Vec<TypeId> = [$([<P$parameter>]::base_signature(),)*]
.into_iter()
.flatten()
.collect();

let universe = world.get_archetype_indices(&base_signature);

let archetypes_indices: Vec<_> = intersection_of_multiple_sets(&[
universe.clone(),
$([<P$parameter>]::filter(&universe, world),)*
])
.into_iter()
.collect();

$(let mut [<borrowed_$parameter>] = [<P$parameter>]::borrow(world, &archetypes_indices).map_err(SystemError::MissingParameter)?;)*

// SAFETY: This is safe because the result from fetch_parameter will not outlive borrowed
unsafe {
if $([<P$parameter>]::iterates_over_entities() ||)* false {
while let ($(Some([<parameter_$parameter>]),)*) = (
$([<P$parameter>]::fetch_parameter(&mut [<borrowed_$parameter>]),)*
) {
if let ($(Some([<parameter_$parameter>]),)*) = (
$([<parameter_$parameter>],)*
) {
(self.function)($([<parameter_$parameter>],)*);
}
}
} else if let ($(Some(Some([<parameter_$parameter>])),)*) = (
$([<P$parameter>]::fetch_parameter(&mut [<borrowed_$parameter>]),)*
) {
(self.function)($([<parameter_$parameter>],)*);
}
let query: Query<($([<P$parameter>],)*)> = Query {
phantom: PhantomData::default(),
world
};

let query_iterator = query.try_into_iter().map_err(SystemError::MissingParameter)?;
for ($([<parameter_$parameter>],)*) in query_iterator {
(self.function)($([<parameter_$parameter>],)*);
}

Ok(())
}
}
Expand Down
170 changes: 162 additions & 8 deletions crates/ecs/src/systems/mod.rs
View file
Original file line number Diff line number Diff line change
Expand Up @@ -4,7 +4,10 @@
pub mod iteration;

use crate::systems::iteration::SequentiallyIterable;
use crate::{ArchetypeIndex, ReadComponentVec, World, WorldError, WriteComponentVec};
use crate::{
intersection_of_multiple_sets, ArchetypeIndex, ReadComponentVec, World, WorldError,
WriteComponentVec,
};
use paste::paste;
use std::any::TypeId;
use std::collections::HashSet;
Expand Down Expand Up @@ -208,12 +211,15 @@ pub type SystemParameterResult<T, E = SystemParameterError> = Result<T, E>;

/// A collection of `ecs::SystemParameter`s that can be passed to a `ecs::System`.
pub trait SystemParameters: Send + Sync {
/// The type of borrowed data for all system parameters
type BorrowedData<'components>;

/// A description of all of the data that is accessed and how (read/write).
fn component_accesses() -> Vec<ComponentAccessDescriptor>;
}

/// Something that can be passed to a [`System`].
pub(crate) trait SystemParameter: Send + Sync + Sized {
pub trait SystemParameter: Send + Sync + Sized {
/// Contains a borrow of components from `ecs::World`.
type BorrowedData<'components>;

Expand All @@ -229,7 +235,7 @@ pub(crate) trait SystemParameter: Send + Sync + Sized {
unsafe fn fetch_parameter(borrowed: &mut Self::BorrowedData<'_>) -> Option<Option<Self>>;

/// A description of what data is accessed and how (read/write).
fn component_access() -> Option<ComponentAccessDescriptor>;
fn component_accesses() -> Vec<ComponentAccessDescriptor>;

/// If the [`SystemParameter`] require that the system iterates over entities.
/// The system will only run once if all [`SystemParameter`]'s `iterates_over_entities` is `false`.
Expand All @@ -251,6 +257,11 @@ pub(crate) trait SystemParameter: Send + Sync + Sized {
fn filter(universe: &HashSet<ArchetypeIndex>, _world: &World) -> HashSet<ArchetypeIndex> {
universe.clone()
}

/// If a system with this [`SystemParameter`] can use intra-system parallelization.
fn support_parallelization() -> bool {
true
}
}

trait SystemParameterFunction<Parameters: SystemParameters>: 'static {}
Expand Down Expand Up @@ -317,8 +328,8 @@ impl<Component: Debug + Send + Sync + 'static + Sized> SystemParameter for Read<
None
}

fn component_access() -> Option<ComponentAccessDescriptor> {
Some(ComponentAccessDescriptor::read::<Component>())
fn component_accesses() -> Vec<ComponentAccessDescriptor> {
vec![ComponentAccessDescriptor::read::<Component>()]
}

fn iterates_over_entities() -> bool {
Expand Down Expand Up @@ -375,8 +386,8 @@ impl<Component: Debug + Send + Sync + 'static + Sized> SystemParameter for Write
None
}

fn component_access() -> Option<ComponentAccessDescriptor> {
Some(ComponentAccessDescriptor::write::<Component>())
fn component_accesses() -> Vec<ComponentAccessDescriptor> {
vec![ComponentAccessDescriptor::write::<Component>()]
}

fn iterates_over_entities() -> bool {
Expand Down Expand Up @@ -408,7 +419,80 @@ impl<'a, Component> DerefMut for Write<'a, Component> {
}
}

/// `Query` allows a system to access components from entities other than the currently iterated.
///
/// # Example
/// ```
/// # use ecs::filter::With;
/// # use ecs::systems::{Query, Read, Write};
/// # #[derive(Debug)] struct Mass(f32);
/// # #[derive(Debug)] struct Velocity(f32);
/// fn print_largest_momentum(query: Query<(Read<Mass>, Read<Velocity>)>) {
/// let mut largest_momentum = 0.0;
/// for (mass, velocity) in query {
/// let momentum = mass.0 * velocity.0;
/// if momentum > largest_momentum {
/// largest_momentum = momentum;
/// }
/// }
/// println!("The largest momentum of all entities is {largest_momentum} kg*m/s.");
/// }
/// ```
#[derive(Debug)]
pub struct Query<'world, P: SystemParameters> {
phantom: PhantomData<P>,
world: &'world World,
}

/// Iterator for [`Query`].
#[derive(Debug)]
pub struct QueryIterator<'components, P: SystemParameters> {
borrowed: P::BorrowedData<'components>,
iterate_over_entities: bool,
iterated_once: bool,
}

impl<'a, P: SystemParameters> SystemParameter for Query<'a, P> {
type BorrowedData<'components> = &'components World;

fn borrow<'world>(
world: &'world World,
_: &[ArchetypeIndex],
) -> SystemParameterResult<Self::BorrowedData<'world>> {
Ok(world)
}

unsafe fn fetch_parameter(borrowed: &mut Self::BorrowedData<'_>) -> Option<Option<Self>> {
#[allow(trivial_casts)]
let world = &*(*borrowed as *const World);
Some(Some(Self {
phantom: PhantomData::default(),
world,
}))
}

fn component_accesses() -> Vec<ComponentAccessDescriptor> {
P::component_accesses()
}

fn iterates_over_entities() -> bool {
false
}

fn base_signature() -> Option<TypeId> {
None
}

fn support_parallelization() -> bool {
Self::component_accesses()
.iter()
.all(|component_access| component_access.is_read())
}
}

impl SystemParameters for () {
type BorrowedData<'components> = ();

fn component_accesses() -> Vec<ComponentAccessDescriptor> {
vec![]
}
Expand All @@ -420,14 +504,84 @@ macro_rules! impl_system_parameter_function {
($($parameter:expr),*) => {
paste! {
impl<$([<P$parameter>]: SystemParameter,)*> SystemParameters for ($([<P$parameter>],)*) {
type BorrowedData<'components> = ($([<P$parameter>]::BorrowedData<'components>,)*);

fn component_accesses() -> Vec<ComponentAccessDescriptor> {
[$([<P$parameter>]::component_access(),)*]
[$([<P$parameter>]::component_accesses(),)*]
.into_iter()
.flatten()
.collect()
}
}

impl<'a, $([<P$parameter>]: SystemParameter,)*> IntoIterator for Query<'a, ($([<P$parameter>],)*)> {
type Item = ($([<P$parameter>],)*);
type IntoIter = QueryIterator<'a, ($([<P$parameter>],)*)>;

fn into_iter(self) -> Self::IntoIter {
Self::try_into_iter(self)
.expect("creating `QueryIterator` should work if the archetypes are in a valid state")
}
}

impl<'a, $([<P$parameter>]: SystemParameter,)*> Query<'a, ($([<P$parameter>],)*)> {
fn try_into_iter(self) -> SystemParameterResult<QueryIterator<'a, ($([<P$parameter>],)*)>> {
let base_signature: Vec<TypeId> = [$([<P$parameter>]::base_signature(),)*]
.into_iter()
.flatten()
.collect();

let universe = self.world.get_archetype_indices(&base_signature);

let archetypes_indices: Vec<_> = intersection_of_multiple_sets(&[
universe.clone(),
$([<P$parameter>]::filter(&universe, self.world),)*
])
.into_iter()
.collect();

let borrowed = (
$([<P$parameter>]::borrow(self.world, &archetypes_indices)?,)*
);

let iterate_over_entities = $([<P$parameter>]::iterates_over_entities() ||)* false;

Ok(QueryIterator {
borrowed,
iterate_over_entities,
iterated_once: false,
})
}
}

impl<'a, $([<P$parameter>]: SystemParameter,)*> Iterator for QueryIterator<'a, ($([<P$parameter>],)*)> {
type Item = ($([<P$parameter>],)*);

fn next(&mut self) -> Option<Self::Item> {
// SAFETY: This is safe because the result from fetch_parameter will not outlive borrowed
unsafe {
if self.iterate_over_entities {
while let ($(Some([<parameter_$parameter>]),)*) = (
$([<P$parameter>]::fetch_parameter(&mut self.borrowed.$parameter),)*
) {
if let ($(Some([<parameter_$parameter>]),)*) = (
$([<parameter_$parameter>],)*
) {
return Some(($([<parameter_$parameter>],)*));
}
}
} else if let (false, $(Some(Some([<parameter_$parameter>])),)*) = (
self.iterated_once,
$([<P$parameter>]::fetch_parameter(&mut self.borrowed.$parameter),)*
) {
self.iterated_once = true;
return Some(($([<parameter_$parameter>],)*));
}
None
}
}
}

impl<F, $([<P$parameter>]: SystemParameter,)*> SystemParameterFunction<($([<P$parameter>],)*)>
for F where F: Fn($([<P$parameter>],)*) + 'static, {}
}
Expand Down

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