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Enable type inference of closure parameter when building dynamic systems.#2

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chescock wants to merge 1 commit intoSystemParamBuilder-basefrom
SystemParamBuilder-type-inference
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Enable type inference of closure parameter when building dynamic systems.#2
chescock wants to merge 1 commit intoSystemParamBuilder-basefrom
SystemParamBuilder-type-inference

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Objective

When building a system from SystemParamBuilders and defining the system as a closure, the compiler should be able to infer the parameter types from the builder types.

Solution

Create methods for each arity that take an argument that implements both SystemParamFunction as well as FnMut(SystemParamItem<P>,...). The explicit FnMut constraint will allow the compiler to infer the necessary higher-ranked lifetimes along with the parameter types.

Example

let system = (LocalBuilder(0u64), ParamBuilder::local::<u64>())
    .build_state(&mut world)
    .build_system(|a, b| *a + *b + 1);

chescock pushed a commit that referenced this pull request Jun 27, 2024
…3906)

# Objective

- Second part of bevyengine#13900 
- based on bevyengine#13905 

## Solution

- check_dir_light_mesh_visibility defers setting the entity's
`ViewVisibility `so that Bevy can schedule it to run in parallel with
`check_point_light_mesh_visibility`.

- Reduce HashMap lookups for directional light checking as much as
possible

- Use `par_iter `to parallelize the checking process within each system.

---------

Co-authored-by: Kristoffer Søholm <k.soeholm@gmail.com>
github-merge-queue bot pushed a commit to bevyengine/bevy that referenced this pull request Aug 12, 2024
# Objective

Support more kinds of system params in buildable systems, such as a
`ParamSet` or `Vec` containing buildable params or tuples of buildable
params.

## Solution

Replace the `BuildableSystemParam` trait with `SystemParamBuilder` to
make it easier to compose builders. Provide implementations for existing
buildable params, plus tuples, `ParamSet`, and `Vec`.

## Examples

```rust
// ParamSet of tuple: 
let system = (ParamSetBuilder((
    QueryParamBuilder::new(|builder| { builder.with::<B>(); }),
    QueryParamBuilder::new(|builder| { builder.with::<C>(); }),
)),)
    .build_state(&mut world)
    .build_system(|mut params: ParamSet<(Query<&mut A>, Query<&mut A>)>| {
        params.p0().iter().count() + params.p1().iter().count()
    });
	
// ParamSet of Vec:
let system = (ParamSetBuilder(vec![
    QueryParamBuilder::new_box(|builder| { builder.with::<B>(); }),
    QueryParamBuilder::new_box(|builder| { builder.with::<C>(); }),
]),)
    .build_state(&mut world)
    .build_system(|mut params: ParamSet<Vec<Query<&mut A>>>| {
        let mut count = 0;
        params.for_each(|mut query| count += query.iter_mut().count());
        count
    });
```

## Migration Guide

The API for `SystemBuilder` has changed. Instead of constructing a
builder with a world and then adding params, you first create a tuple of
param builders and then supply the world.

```rust
// Before
let system = SystemBuilder::<()>::new(&mut world)
    .local::<u64>()
    .builder::<Local<u64>>(|x| *x = 10)
    .builder::<Query<&A>>(|builder| { builder.with::<B>(); })
    .build(system);

// After
let system = (
    ParamBuilder,
    LocalBuilder(10),
    QueryParamBuilder::new(|builder| { builder.with::<B>(); }),
)
    .build_state(&mut world)
    .build_system(system);
```

## Possible Future Work

Here are a few possible follow-up changes. I coded them up to prove that
this API can support them, but they aren't necessary for this PR.

* chescock#1
* chescock#2
* chescock#3
@chescock chescock closed this Aug 12, 2024
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