# Objective
- `SystemStates` rock for dealing with exclusive world access, but are hard to figure out how to use.
- Fixes#3341.
## Solution
- Clearly document how to use `SystemState`, and why they're useful as an end-user.
What is says on the tin.
This has got more to do with making `clippy` slightly more *quiet* than it does with changing anything that might greatly impact readability or performance.
that said, deriving `Default` for a couple of structs is a nice easy win
# Objective
- Fixes#3078
- Fixes#1397
## Solution
- Implement Commands::init_resource.
- Also implement for World, for consistency and to simplify internal structure.
- While we're here, clean up some of the docs for Command and World resource modification.
# Objective
- Provide impls for mutable types to relevant immutable types.
- Closes#2005
## Solution
- impl From<ResMut> for Res
- impl From<NonSendMut> for NonSend
- Mut to &/&mut already impl'd in change_detection_impl! macro
# Objective
Make it possible to use `&World` as a system parameter
## Solution
It seems like all the pieces were already in place, very simple impl
Co-authored-by: Carter Anderson <mcanders1@gmail.com>
This is my first contribution to this exciting project! Thanks so much for your wonderful work. If there is anything that I can improve about this PR, please let me know :)
# Objective
- Fixes#2899
- If a simple one-off command is needed to be added within a System, this simplifies that process so that we can simply do `commands.add(|world: &mut World| { /* code here */ })` instead of defining a custom type implementing `Command`.
## Solution
- This is achieved by `impl Command for F where F: FnOnce(&mut World) + Send + Sync + 'static` as just calling the function.
I am not sure if the bounds can be further relaxed but needed the whole `Send`, `Sync`, and `'static` to get it to compile.
# Objective
A user on Discord couldn't derive SystemParam for this Struct:
```rs
#[derive(SystemParam)]
pub struct SpatialQuery<'w, 's, Q: WorldQuery + Send + Sync + 'static, F: WorldQuery + Send + Sync + 'static = ()>
where
F::Fetch: FilterFetch,
{
query: Query<'w, 's, (C, &'static Transform), F>,
}
```
## Solution
1. The `where`-clause is now also copied to the `SystemParamFetch` impl Block.
2. The `SystemParamState` impl Block no longer gets any defaults for generics
Co-authored-by: MinerSebas <66798382+MinerSebas@users.noreply.github.com>
# Objective
- Calling .id() has no purpose unless you use the Entity returned
- This is an easy source of confusion for beginners.
- This is easily missed during refactors.
## Solution
- Mark the appropriate methods as #[must_use]
# Objective
- Removes warning about accidently inserting bundles with `EntityCommands::insert`, but since a component now needs to implement `Component` it is unnecessary.
#3457 adds the `doc_markdown` clippy lint, which checks doc comments to make sure code identifiers are escaped with backticks. This causes a lot of lint errors, so this is one of a number of PR's that will fix those lint errors one crate at a time.
This PR fixes lints in the `bevy_ecs` crate.
# Objective
- Fixes#1920.
- Users often want to know how to get the values of removed components (#1655).
- Stand-alone `bevy_ecs` behavior is very unintuitive, as `World::clear_trackers()` must be manually called.
- Fixes#2999 by extending the existing test (thanks @hymm for pointing me to it) to be clearer and check for component removal as well.
## Solution
- Better docs!
- Better tests!
# Objective
- While reading code, found some queries that are `mut` and not used as such
## Solution
- Remove `mut` when possible
Co-authored-by: François <8672791+mockersf@users.noreply.github.com>
A sample implementation of how to have `iter()` work on mutable queries without breaking aliasing rules.
# Objective
- Fixes#753
## Solution
- Added a ReadOnlyFetch to WorldQuery that is the `&T` version of `&mut T` that is used to specify the return type for read only operations like `iter()`.
- ~~As the comment suggests specifying the bound doesn't work due to restrictions on defining recursive implementations (like `Or`). However bounds on the functions are fine~~ Never mind I misread how `Or` was constructed, bounds now exist.
- Note that the only mutable one has a new `Fetch` for readonly as the `State` has to be the same for any of this to work
Co-authored-by: Carter Anderson <mcanders1@gmail.com>
This is a squash-and-rebase of @Ku95's documentation of the new renderer onto the latest `pipelined-rendering` branch.
Original PR is #2884.
Co-authored-by: dataphract <dataphract@gmail.com>
Co-authored-by: Carter Anderson <mcanders1@gmail.com>
# Objective
bevy_ecs has several compile_fail tests that assert lifetime safety. In the past, these tests have been green for the wrong reasons (see e.g. #2984). This PR makes sure, that they will fail if the compiler error changes.
## Solution
Use [trybuild](https://crates.io/crates/trybuild) to assert the compiler errors.
The UI tests are in a separate crate that is not part of the Bevy workspace. This is to ensure that they do not break Bevy's crater builds. The tests get executed by the CI workflow on the stable toolchain.
# Objective
- Improve error descriptions and help understand how to fix them
- I noticed one today that could be expanded, it seemed like a good starting point
## Solution
- Start something like https://github.com/rust-lang/rust/tree/master/compiler/rustc_error_codes/src/error_codes
- Remove sentence about Rust mutability rules which is not very helpful in the error message
I decided to start the error code with B for Bevy so that they're not confused with error code from rust (which starts with E)
Longer term, there are a few more evolutions that can continue this:
- the code samples should be compiled check, and even executed for some of them to check they have the correct error code in a panic
- the error could be build on a page in the website like https://doc.rust-lang.org/error-index.html
- most panic should have their own error code
# Objective
- Bevy has several `compile_fail` test
- #2254 added `#[derive(Component)]`
- Those tests now fail for a different reason.
- This was not caught as these test still "successfully" failed to compile.
## Solution
- Add `#[derive(Component)]` to the doctest
- Also changed their cfg attribute from `doc` to `doctest`, so that these tests don't appear when running `cargo doc` with `--document-private-items`
#2605 changed the lifetime annotations on `get_component` introducing unsoundness as you could keep the returned borrow even after using the query.
Example unsoundness:
```rust
use bevy::prelude::*;
fn main() {
App::new()
.add_startup_system(startup)
.add_system(unsound)
.run();
}
#[derive(Debug, Component, PartialEq, Eq)]
struct Foo(Vec<u32>);
fn startup(mut c: Commands) {
let e = c.spawn().insert(Foo(vec![10])).id();
c.insert_resource(e);
}
fn unsound(mut q: Query<&mut Foo>, res: Res<Entity>) {
let foo = q.get_component::<Foo>(*res).unwrap();
let mut foo2 = q.iter_mut().next().unwrap();
let first_elem = &foo.0[0];
for _ in 0..16 {
foo2.0.push(12);
}
dbg!(*first_elem);
}
```
output:
`[src/main.rs:26] *first_elem = 0`
This implements the most minimal variant of #1843 - a derive for marker trait. This is a prerequisite to more complicated features like statically defined storage type or opt-out component reflection.
In order to make component struct's purpose explicit and avoid misuse, it must be annotated with `#[derive(Component)]` (manual impl is discouraged for compatibility). Right now this is just a marker trait, but in the future it might be expanded. Making this change early allows us to make further changes later without breaking backward compatibility for derive macro users.
This already prevents a lot of issues, like using bundles in `insert` calls. Primitive types are no longer valid components as well. This can be easily worked around by adding newtype wrappers and deriving `Component` for them.
One funny example of prevented bad code (from our own tests) is when an newtype struct or enum variant is used. Previously, it was possible to write `insert(Newtype)` instead of `insert(Newtype(value))`. That code compiled, because function pointers (in this case newtype struct constructor) implement `Send + Sync + 'static`, so we allowed them to be used as components. This is no longer the case and such invalid code will trigger a compile error.
Co-authored-by: = <=>
Co-authored-by: TheRawMeatball <therawmeatball@gmail.com>
Co-authored-by: Carter Anderson <mcanders1@gmail.com>
# Objective
Fixes these issues:
- `WorldId`s currently aren't necessarily unique
- I want to guarantee that they're unique to safeguard my librarified version of https://github.com/bevyengine/bevy/discussions/2805
- There probably hasn't been a collision yet, but they could technically collide
- `SystemId` isn't used for anything
- It's no longer used now that `Locals` are stored within the `System`.
- `bevy_ecs` depends on rand
## Solution
- Instead of randomly generating `WorldId`s, just use an incrementing atomic counter, panicing on overflow.
- Remove `SystemId`
- We do need to allow Locals for exclusive systems at some point, but exclusive systems couldn't access their own `SystemId` anyway.
- Now that these don't depend on rand, move it to a dev-dependency
## Todo
Determine if `WorldId` should be `u32` based instead
This changes how render logic is composed to make it much more modular. Previously, all extraction logic was centralized for a given "type" of rendered thing. For example, we extracted meshes into a vector of ExtractedMesh, which contained the mesh and material asset handles, the transform, etc. We looked up bindings for "drawn things" using their index in the `Vec<ExtractedMesh>`. This worked fine for built in rendering, but made it hard to reuse logic for "custom" rendering. It also prevented us from reusing things like "extracted transforms" across contexts.
To make rendering more modular, I made a number of changes:
* Entities now drive rendering:
* We extract "render components" from "app components" and store them _on_ entities. No more centralized uber lists! We now have true "ECS-driven rendering"
* To make this perform well, I implemented #2673 in upstream Bevy for fast batch insertions into specific entities. This was merged into the `pipelined-rendering` branch here: #2815
* Reworked the `Draw` abstraction:
* Generic `PhaseItems`: each draw phase can define its own type of "rendered thing", which can define its own "sort key"
* Ported the 2d, 3d, and shadow phases to the new PhaseItem impl (currently Transparent2d, Transparent3d, and Shadow PhaseItems)
* `Draw` trait and and `DrawFunctions` are now generic on PhaseItem
* Modular / Ergonomic `DrawFunctions` via `RenderCommands`
* RenderCommand is a trait that runs an ECS query and produces one or more RenderPass calls. Types implementing this trait can be composed to create a final DrawFunction. For example the DrawPbr DrawFunction is created from the following DrawCommand tuple. Const generics are used to set specific bind group locations:
```rust
pub type DrawPbr = (
SetPbrPipeline,
SetMeshViewBindGroup<0>,
SetStandardMaterialBindGroup<1>,
SetTransformBindGroup<2>,
DrawMesh,
);
```
* The new `custom_shader_pipelined` example illustrates how the commands above can be reused to create a custom draw function:
```rust
type DrawCustom = (
SetCustomMaterialPipeline,
SetMeshViewBindGroup<0>,
SetTransformBindGroup<2>,
DrawMesh,
);
```
* ExtractComponentPlugin and UniformComponentPlugin:
* Simple, standardized ways to easily extract individual components and write them to GPU buffers
* Ported PBR and Sprite rendering to the new primitives above.
* Removed staging buffer from UniformVec in favor of direct Queue usage
* Makes UniformVec much easier to use and more ergonomic. Completely removes the need for custom render graph nodes in these contexts (see the PbrNode and view Node removals and the much simpler call patterns in the relevant Prepare systems).
* Added a many_cubes_pipelined example to benchmark baseline 3d rendering performance and ensure there were no major regressions during this port. Avoiding regressions was challenging given that the old approach of extracting into centralized vectors is basically the "optimal" approach. However thanks to a various ECS optimizations and render logic rephrasing, we pretty much break even on this benchmark!
* Lifetimeless SystemParams: this will be a bit divisive, but as we continue to embrace "trait driven systems" (ex: ExtractComponentPlugin, UniformComponentPlugin, DrawCommand), the ergonomics of `(Query<'static, 'static, (&'static A, &'static B, &'static)>, Res<'static, C>)` were getting very hard to bear. As a compromise, I added "static type aliases" for the relevant SystemParams. The previous example can now be expressed like this: `(SQuery<(Read<A>, Read<B>)>, SRes<C>)`. If anyone has better ideas / conflicting opinions, please let me know!
* RunSystem trait: a way to define Systems via a trait with a SystemParam associated type. This is used to implement the various plugins mentioned above. I also added SystemParamItem and QueryItem type aliases to make "trait stye" ecs interactions nicer on the eyes (and fingers).
* RenderAsset retrying: ensures that render assets are only created when they are "ready" and allows us to create bind groups directly inside render assets (which significantly simplified the StandardMaterial code). I think ultimately we should swap this out on "asset dependency" events to wait for dependencies to load, but this will require significant asset system changes.
* Updated some built in shaders to account for missing MeshUniform fields
## Objective
The upcoming Bevy Book makes many references to the API documentation of bevy.
Most references belong to the first two chapters of the Bevy Book:
- bevyengine/bevy-website#176
- bevyengine/bevy-website#182
This PR attempts to improve the documentation of `bevy_ecs` and `bevy_app` in order to help readers of the Book who want to delve deeper into technical details.
## Solution
- Add crate and level module documentation
- Document the most important items (basically those included in the preludes), with the following style, where applicable:
- **Summary.** Short description of the item.
- **Second paragraph.** Detailed description of the item, without going too much in the implementation.
- **Code example(s).**
- **Safety or panic notes.**
## Collaboration
Any kind of collaboration is welcome, especially corrections, wording, new ideas and guidelines on where the focus should be put in.
---
### Related issues
- Fixes#2246
This updates the `pipelined-rendering` branch to use the latest `bevy_ecs` from `main`. This accomplishes a couple of goals:
1. prepares for upcoming `custom-shaders` branch changes, which were what drove many of the recent bevy_ecs changes on `main`
2. prepares for the soon-to-happen merge of `pipelined-rendering` into `main`. By including bevy_ecs changes now, we make that merge simpler / easier to review.
I split this up into 3 commits:
1. **add upstream bevy_ecs**: please don't bother reviewing this content. it has already received thorough review on `main` and is a literal copy/paste of the relevant folders (the old folders were deleted so the directories are literally exactly the same as `main`).
2. **support manual buffer application in stages**: this is used to enable the Extract step. we've already reviewed this once on the `pipelined-rendering` branch, but its worth looking at one more time in the new context of (1).
3. **support manual archetype updates in QueryState**: same situation as (2).
# Objective
The vast majority of `.single()` usage I've seen is immediately followed by a `.unwrap()`. Since it seems most people use it without handling the error, I think making it easier to just get what you want fast while also having a more verbose alternative when you want to handle the error could help.
## Solution
Instead of having a lot of `.unwrap()` everywhere, this PR introduces a `try_single()` variant that behaves like the current `.single()` and make the new `.single()` panic on error.
# Objective
Sometimes, the unwraps in `entity_mut` could fail here, if the entity was despawned *before* this command was applied.
The simplest case involves two command buffers:
```rust
use bevy::prelude::*;
fn b(mut commands1: Commands, mut commands2: Commands) {
let id = commands2.spawn().insert_bundle(()).id();
commands1.entity(id).despawn();
}
fn main() {
App::build().add_system(b.system()).run();
}
```
However, a more complicated version arises in the case of ambiguity:
```rust
use std::time::Duration;
use bevy::{app::ScheduleRunnerPlugin, prelude::*};
use rand::Rng;
fn cleanup(mut e: ResMut<Option<Entity>>) {
*e = None;
}
fn sleep_randomly() {
let mut rng = rand::thread_rng();
std:🧵:sleep(Duration::from_millis(rng.gen_range(0..50)));
}
fn spawn(mut commands: Commands, mut e: ResMut<Option<Entity>>) {
*e = Some(commands.spawn().insert_bundle(()).id());
}
fn despawn(mut commands: Commands, e: Res<Option<Entity>>) {
let mut rng = rand::thread_rng();
std:🧵:sleep(Duration::from_millis(rng.gen_range(0..50)));
if let Some(e) = *e {
commands.entity(e).despawn();
}
}
fn main() {
App::build()
.add_system(cleanup.system().label("cleanup"))
.add_system(sleep_randomly.system().label("before_despawn"))
.add_system(despawn.system().after("cleanup").after("before_despawn"))
.add_system(sleep_randomly.system().label("before_spawn"))
.add_system(spawn.system().after("cleanup").after("before_spawn"))
.insert_resource(None::<Entity>)
.add_plugin(ScheduleRunnerPlugin::default())
.run();
}
```
In the cases where this example crashes, it's because `despawn` was ordered before `spawn` in the topological ordering of systems (which determines when buffers are applied). However, `despawn` actually ran *after* `spawn`, because these systems are ambiguous, so the jiggles in the sleeping time triggered a case where this works.
## Solution
- Give a better error message
# Objective
Fix `Option<NonSend<T>>` to work when T isn't `Send`
Fix `Option<NonSendMut<T>>` to work when T isnt in the world.
## Solution
Simple two row fix, properly initialize T in `OptionNonSendState` and remove `T: Component` bound for `Option<NonSendMut<T>>`
also added a rudimentary test
Co-authored-by: Ïvar Källström <ivar.kallstrom@gmail.com>
This upstreams the code changes used by the new renderer to enable cross-app Entity reuse:
* Spawning at specific entities
* get_or_spawn: spawns an entity if it doesn't already exist and returns an EntityMut
* insert_or_spawn_batch: the batched equivalent to `world.get_or_spawn(entity).insert_bundle(bundle)`
* Clearing entities and storages
* Allocating Entities with "invalid" archetypes. These entities cannot be queried / are treated as "non existent". They serve as "reserved" entities that won't show up when calling `spawn()`. They must be "specifically spawned at" using apis like `get_or_spawn(entity)`.
In combination, these changes enable the "render world" to clear entities / storages each frame and reserve all "app world entities". These can then be spawned during the "render extract step".
This refactors "spawn" and "insert" code in a way that I think is a massive improvement to legibility and re-usability. It also yields marginal performance wins by reducing some duplicate lookups (less than a percentage point improvement on insertion benchmarks). There is also some potential for future unsafe reduction (by making BatchSpawner and BatchInserter generic). But for now I want to cut down generic usage to a minimum to encourage smaller binaries and faster compiles.
This is currently a draft because it needs more tests (although this code has already had some real-world testing on my custom-shaders branch).
I also fixed the benchmarks (which currently don't compile!) / added new ones to illustrate batching wins.
After these changes, Bevy ECS is basically ready to accommodate the new renderer. I think the biggest missing piece at this point is "sub apps".
# Objective
Enable using exact World lifetimes during read-only access . This is motivated by the new renderer's need to allow read-only world-only queries to outlive the query itself (but still be constrained by the world lifetime).
For example:
115b170d1f/pipelined/bevy_pbr2/src/render/mod.rs (L774)
## Solution
Split out SystemParam state and world lifetimes and pipe those lifetimes up to read-only Query ops (and add into_inner for Res). According to every safety test I've run so far (except one), this is safe (see the temporary safety test commit). Note that changing the mutable variants to the new lifetimes would allow aliased mutable pointers (try doing that to see how it affects the temporary safety tests).
The new state lifetime on SystemParam does make `#[derive(SystemParam)]` more cumbersome (the current impl requires PhantomData if you don't use both lifetimes). We can make this better by detecting whether or not a lifetime is used in the derive and adjusting accordingly, but that should probably be done in its own pr.
## Why is this a draft?
The new lifetimes break QuerySet safety in one very specific case (see the query_set system in system_safety_test). We need to solve this before we can use the lifetimes given.
This is due to the fact that QuerySet is just a wrapper over Query, which now relies on world lifetimes instead of `&self` lifetimes to prevent aliasing (but in systems, each Query has its own implied lifetime, not a centralized world lifetime). I believe the fix is to rewrite QuerySet to have its own World lifetime (and own the internal reference). This will complicate the impl a bit, but I think it is doable. I'm curious if anyone else has better ideas.
Personally, I think these new lifetimes need to happen. We've gotta have a way to directly tie read-only World queries to the World lifetime. The new renderer is the first place this has come up, but I doubt it will be the last. Worst case scenario we can come up with a second `WorldLifetimeQuery<Q, F = ()>` parameter to enable these read-only scenarios, but I'd rather not add another type to the type zoo.
# Objective
- Remove all the `.system()` possible.
- Check for remaining missing cases.
## Solution
- Remove all `.system()`, fix compile errors
- 32 calls to `.system()` remains, mostly internals, the few others should be removed after #2446
This is extracted out of eb8f973646476b4a4926ba644a77e2b3a5772159 and includes some additional changes to remove all references to AppBuilder and fix examples that still used App::build() instead of App::new(). In addition I didn't extract the sub app feature as it isn't ready yet.
You can use `git diff --diff-filter=M eb8f973646476b4a4926ba644a77e2b3a5772159` to find all differences in this PR. The `--diff-filtered=M` filters all files added in the original commit but not in this commit away.
Co-Authored-By: Carter Anderson <mcanders1@gmail.com>
* bevy_pbr2: Add support for most of the StandardMaterial textures
Normal maps are not included here as they require tangents in a vertex attribute.
* bevy_pbr2: Ensure RenderCommandQueue is ready for PbrShaders init
* texture_pipelined: Add a light to the scene so we can see stuff
* WIP bevy_pbr2: back to front sorting hack
* bevy_pbr2: Uniform control flow for texture sampling in pbr.frag
From 'fintelia' on the Bevy Render Rework Round 2 discussion:
"My understanding is that GPUs these days never use the "execute both branches
and select the result" strategy. Rather, what they do is evaluate the branch
condition on all threads of a warp, and jump over it if all of them evaluate to
false. If even a single thread needs to execute the if statement body, however,
then the remaining threads are paused until that is completed."
* bevy_pbr2: Simplify texture and sampler names
The StandardMaterial_ prefix is no longer needed
* bevy_pbr2: Match default 'AmbientColor' of current bevy_pbr for now
* bevy_pbr2: Convert from non-linear to linear sRGB for the color uniform
* bevy_pbr2: Add pbr_pipelined example
* Fix view vector in pbr frag to work in ortho
* bevy_pbr2: Use a 90 degree y fov and light range projection for lights
* bevy_pbr2: Add AmbientLight resource
* bevy_pbr2: Convert PointLight color to linear sRGB for use in fragment shader
* bevy_pbr2: pbr.frag: Rename PointLight.projection to view_projection
The uniform contains the view_projection matrix so this was incorrect.
* bevy_pbr2: PointLight is an OmniLight as it has a radius
* bevy_pbr2: Factoring out duplicated code
* bevy_pbr2: Implement RenderAsset for StandardMaterial
* Remove unnecessary texture and sampler clones
* fix comment formatting
* remove redundant Buffer:from
* Don't extract meshes when their material textures aren't ready
* make missing textures in the queue step an error
Co-authored-by: Aevyrie <aevyrie@gmail.com>
Co-authored-by: Carter Anderson <mcanders1@gmail.com>
# Objective
- Continue work of #2398 and friends.
- Make `.system()` optional in chaining.
## Solution
- Slight change to `IntoChainSystem` signature and implementation.
- Remove some usages of `.system()` in the chaining example, to verify the implementation.
---
I swear, I'm not splitting these up on purpose, I just legit forgot about most of the things where `System` appears in public API, and my trait usage explorer mingles that with the gajillion internal uses.
In case you're wondering what happened to part 5, #2446 ate it.
