# Objective
Now that #13432 has been merged, it's important we update our reflected
types to properly opt into this feature. If we do not, then this could
cause issues for users downstream who want to make use of
reflection-based cloning.
## Solution
This PR is broken into 4 commits:
1. Add `#[reflect(Clone)]` on all types marked `#[reflect(opaque)]` that
are also `Clone`. This is mandatory as these types would otherwise cause
the cloning operation to fail for any type that contains it at any
depth.
2. Update the reflection example to suggest adding `#[reflect(Clone)]`
on opaque types.
3. Add `#[reflect(clone)]` attributes on all fields marked
`#[reflect(ignore)]` that are also `Clone`. This prevents the ignored
field from causing the cloning operation to fail.
Note that some of the types that contain these fields are also `Clone`,
and thus can be marked `#[reflect(Clone)]`. This makes the
`#[reflect(clone)]` attribute redundant. However, I think it's safer to
keep it marked in the case that the `Clone` impl/derive is ever removed.
I'm open to removing them, though, if people disagree.
4. Finally, I added `#[reflect(Clone)]` on all types that are also
`Clone`. While not strictly necessary, it enables us to reduce the
generated output since we can just call `Clone::clone` directly instead
of calling `PartialReflect::reflect_clone` on each variant/field. It
also means we benefit from any optimizations or customizations made in
the `Clone` impl, including directly dereferencing `Copy` values and
increasing reference counters.
Along with that change I also took the liberty of adding any missing
registrations that I saw could be applied to the type as well, such as
`Default`, `PartialEq`, and `Hash`. There were hundreds of these to
edit, though, so it's possible I missed quite a few.
That last commit is **_massive_**. There were nearly 700 types to
update. So it's recommended to review the first three before moving onto
that last one.
Additionally, I can break the last commit off into its own PR or into
smaller PRs, but I figured this would be the easiest way of doing it
(and in a timely manner since I unfortunately don't have as much time as
I used to for code contributions).
## Testing
You can test locally with a `cargo check`:
```
cargo check --workspace --all-features
```
Extracted from my DLSS branch.
## Changelog
* Added `source_texture` and `destination_texture` to
`PostProcessWrite`, in addition to the existing texture views.
# Objective
Prevents duplicate implementation between IntoSystemConfigs and
IntoSystemSetConfigs using a generic, adds a NodeType trait for more
config flexibility (opening the door to implement
https://github.com/bevyengine/bevy/issues/14195?).
## Solution
Followed writeup by @ItsDoot:
https://hackmd.io/@doot/rJeefFHc1x
Removes IntoSystemConfigs and IntoSystemSetConfigs, instead using
IntoNodeConfigs with generics.
## Testing
Pending
---
## Showcase
N/A
## Migration Guide
SystemSetConfigs -> NodeConfigs<InternedSystemSet>
SystemConfigs -> NodeConfigs<ScheduleSystem>
IntoSystemSetConfigs -> IntoNodeConfigs<InternedSystemSet, M>
IntoSystemConfigs -> IntoNodeConfigs<ScheduleSystem, M>
---------
Co-authored-by: Christian Hughes <9044780+ItsDoot@users.noreply.github.com>
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
# Objective
There are currently three ways to access the parent stored on a ChildOf
relationship:
1. `child_of.parent` (field accessor)
2. `child_of.get()` (get function)
3. `**child_of` (Deref impl)
I will assert that we should only have one (the field accessor), and
that the existence of the other implementations causes confusion and
legibility issues. The deref approach is heinous, and `child_of.get()`
is significantly less clear than `child_of.parent`.
## Solution
Remove `impl Deref for ChildOf` and `ChildOf::get`.
The one "downside" I'm seeing is that:
```rust
entity.get::<ChildOf>().map(ChildOf::get)
```
Becomes this:
```rust
entity.get::<ChildOf>().map(|c| c.parent)
```
I strongly believe that this is worth the increased clarity and
consistency. I'm also not really a huge fan of the "pass function
pointer to map" syntax. I think most people don't think this way about
maps. They think in terms of a function that takes the item in the
Option and returns the result of some action on it.
## Migration Guide
```rust
// Before
**child_of
// After
child_of.parent
// Before
child_of.get()
// After
child_of.parent
// Before
entity.get::<ChildOf>().map(ChildOf::get)
// After
entity.get::<ChildOf>().map(|c| c.parent)
```
# Objective
fixes#17896
## Solution
Change ChildOf ( Entity ) to ChildOf { parent: Entity }
by doing this we also allow users to use named structs for relationship
derives, When you have more than 1 field in a struct with named fields
the macro will look for a field with the attribute #[relationship] and
all of the other fields should implement the Default trait. Unnamed
fields are still supported.
When u have a unnamed struct with more than one field the macro will
fail.
Do we want to support something like this ?
```rust
#[derive(Component)]
#[relationship_target(relationship = ChildOf)]
pub struct Children (#[relationship] Entity, u8);
```
I could add this, it but doesn't seem nice.
## Testing
crates/bevy_ecs - cargo test
## Showcase
```rust
use bevy_ecs::component::Component;
use bevy_ecs::entity::Entity;
#[derive(Component)]
#[relationship(relationship_target = Children)]
pub struct ChildOf {
#[relationship]
pub parent: Entity,
internal: u8,
};
#[derive(Component)]
#[relationship_target(relationship = ChildOf)]
pub struct Children {
children: Vec<Entity>
};
```
---------
Co-authored-by: Tim Overbeek <oorbecktim@Tims-MacBook-Pro.local>
Co-authored-by: Tim Overbeek <oorbecktim@c-001-001-042.client.nl.eduvpn.org>
Co-authored-by: Tim Overbeek <oorbecktim@c-001-001-059.client.nl.eduvpn.org>
Co-authored-by: Tim Overbeek <oorbecktim@c-001-001-054.client.nl.eduvpn.org>
Co-authored-by: Tim Overbeek <oorbecktim@c-001-001-027.client.nl.eduvpn.org>
# Objective
- Fixes#17960
## Solution
- Followed the [edition upgrade
guide](https://doc.rust-lang.org/edition-guide/editions/transitioning-an-existing-project-to-a-new-edition.html)
## Testing
- CI
---
## Summary of Changes
### Documentation Indentation
When using lists in documentation, proper indentation is now linted for.
This means subsequent lines within the same list item must start at the
same indentation level as the item.
```rust
/* Valid */
/// - Item 1
/// Run-on sentence.
/// - Item 2
struct Foo;
/* Invalid */
/// - Item 1
/// Run-on sentence.
/// - Item 2
struct Foo;
```
### Implicit `!` to `()` Conversion
`!` (the never return type, returned by `panic!`, etc.) no longer
implicitly converts to `()`. This is particularly painful for systems
with `todo!` or `panic!` statements, as they will no longer be functions
returning `()` (or `Result<()>`), making them invalid systems for
functions like `add_systems`. The ideal fix would be to accept functions
returning `!` (or rather, _not_ returning), but this is blocked on the
[stabilisation of the `!` type
itself](https://doc.rust-lang.org/std/primitive.never.html), which is
not done.
The "simple" fix would be to add an explicit `-> ()` to system
signatures (e.g., `|| { todo!() }` becomes `|| -> () { todo!() }`).
However, this is _also_ banned, as there is an existing lint which (IMO,
incorrectly) marks this as an unnecessary annotation.
So, the "fix" (read: workaround) is to put these kinds of `|| -> ! { ...
}` closuers into variables and give the variable an explicit type (e.g.,
`fn()`).
```rust
// Valid
let system: fn() = || todo!("Not implemented yet!");
app.add_systems(..., system);
// Invalid
app.add_systems(..., || todo!("Not implemented yet!"));
```
### Temporary Variable Lifetimes
The order in which temporary variables are dropped has changed. The
simple fix here is _usually_ to just assign temporaries to a named
variable before use.
### `gen` is a keyword
We can no longer use the name `gen` as it is reserved for a future
generator syntax. This involved replacing uses of the name `gen` with
`r#gen` (the raw-identifier syntax).
### Formatting has changed
Use statements have had the order of imports changed, causing a
substantial +/-3,000 diff when applied. For now, I have opted-out of
this change by amending `rustfmt.toml`
```toml
style_edition = "2021"
```
This preserves the original formatting for now, reducing the size of
this PR. It would be a simple followup to update this to 2024 and run
`cargo fmt`.
### New `use<>` Opt-Out Syntax
Lifetimes are now implicitly included in RPIT types. There was a handful
of instances where it needed to be added to satisfy the borrow checker,
but there may be more cases where it _should_ be added to avoid
breakages in user code.
### `MyUnitStruct { .. }` is an invalid pattern
Previously, you could match against unit structs (and unit enum
variants) with a `{ .. }` destructuring. This is no longer valid.
### Pretty much every use of `ref` and `mut` are gone
Pattern binding has changed to the point where these terms are largely
unused now. They still serve a purpose, but it is far more niche now.
### `iter::repeat(...).take(...)` is bad
New lint recommends using the more explicit `iter::repeat_n(..., ...)`
instead.
## Migration Guide
The lifetimes of functions using return-position impl-trait (RPIT) are
likely _more_ conservative than they had been previously. If you
encounter lifetime issues with such a function, please create an issue
to investigate the addition of `+ use<...>`.
## Notes
- Check the individual commits for a clearer breakdown for what
_actually_ changed.
---------
Co-authored-by: François Mockers <francois.mockers@vleue.com>
The `check_visibility` system currently follows this algorithm:
1. Store all meshes that were visible last frame in the
`PreviousVisibleMeshes` set.
2. Determine which meshes are visible. For each such visible mesh,
remove it from `PreviousVisibleMeshes`.
3. Mark all meshes that remain in `PreviousVisibleMeshes` as invisible.
This algorithm would be correct if the `check_visibility` were the only
system that marked meshes visible. However, it's not: the shadow-related
systems `check_dir_light_mesh_visibility` and
`check_point_light_mesh_visibility` can as well. This results in the
following sequence of events for meshes that are in a shadow map but
*not* visible from a camera:
A. `check_visibility` runs, finds that no camera contains these meshes,
and marks them hidden, which sets the changed flag.
B. `check_dir_light_mesh_visibility` and/or
`check_point_light_mesh_visibility` run, discover that these meshes
are visible in the shadow map, and marks them as visible, again
setting the `ViewVisibility` changed flag.
C. During the extraction phase, the mesh extraction system sees that
`ViewVisibility` is changed and re-extracts the mesh.
This is inefficient and results in needless work during rendering.
This patch fixes the issue in two ways:
* The `check_dir_light_mesh_visibility` and
`check_point_light_mesh_visibility` systems now remove meshes that they
discover from `PreviousVisibleMeshes`.
* Step (3) above has been moved from `check_visibility` to a separate
system, `mark_newly_hidden_entities_invisible`. This system runs after
all visibility-determining systems, ensuring that
`PreviousVisibleMeshes` contains only those meshes that truly became
invisible on this frame.
This fix dramatically improves the performance of [the Caldera
benchmark], when combined with several other patches I've submitted.
[the Caldera benchmark]:
https://github.com/DGriffin91/bevy_caldera_scene
PR #17688 broke motion vector computation, and therefore motion blur,
because it enabled retention of `MeshInputUniform`s, and
`MeshInputUniform`s contain the indices of the previous frame's
transform and the previous frame's skinned mesh joint matrices. On frame
N, if a `MeshInputUniform` is retained on GPU from the previous frame,
the `previous_input_index` and `previous_skin_index` would refer to the
indices for frame N - 2, not the index for frame N - 1.
This patch fixes the problems. It solves these issues in two different
ways, one for transforms and one for skins:
1. To fix transforms, this patch supplies the *frame index* to the
shader as part of the view uniforms, and specifies which frame index
each mesh's previous transform refers to. So, in the situation described
above, the frame index would be N, the previous frame index would be N -
1, and the `previous_input_frame_number` would be N - 2. The shader can
now detect this situation and infer that the mesh has been retained, and
can therefore conclude that the mesh's transform hasn't changed.
2. To fix skins, this patch replaces the explicit `previous_skin_index`
with an invariant that the index of the joints for the current frame and
the index of the joints for the previous frame are the same. This means
that the `MeshInputUniform` never has to be updated even if the skin is
animated. The downside is that we have to copy joint matrices from the
previous frame's buffer to the current frame's buffer in
`extract_skins`.
The rationale behind (2) is that we currently have no mechanism to
detect when joints that affect a skin have been updated, short of
comparing all the transforms and setting a flag for
`extract_meshes_for_gpu_building` to consume, which would regress
performance as we want `extract_skins` and
`extract_meshes_for_gpu_building` to be able to run in parallel.
To test this change, use `cargo run --example motion_blur`.
Didn't remove WgpuWrapper. Not sure if it's needed or not still.
## Testing
- Did you test these changes? If so, how? Example runner
- Are there any parts that need more testing? Web (portable atomics
thingy?), DXC.
## Migration Guide
- Bevy has upgraded to [wgpu
v24](https://github.com/gfx-rs/wgpu/blob/trunk/CHANGELOG.md#v2400-2025-01-15).
- When using the DirectX 12 rendering backend, the new priority system
for choosing a shader compiler is as follows:
- If the `WGPU_DX12_COMPILER` environment variable is set at runtime, it
is used
- Else if the new `statically-linked-dxc` feature is enabled, a custom
version of DXC will be statically linked into your app at compile time.
- Else Bevy will look in the app's working directory for
`dxcompiler.dll` and `dxil.dll` at runtime.
- Else if they are missing, Bevy will fall back to FXC (not recommended)
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: IceSentry <c.giguere42@gmail.com>
Co-authored-by: François Mockers <francois.mockers@vleue.com>
# Objective
- Make use of the new `weak_handle!` macro added in
https://github.com/bevyengine/bevy/pull/17384
## Solution
- Migrate bevy from `Handle::weak_from_u128` to the new `weak_handle!`
macro that takes a random UUID
- Deprecate `Handle::weak_from_u128`, since there are no remaining use
cases that can't also be addressed by constructing the type manually
## Testing
- `cargo run -p ci -- test`
---
## Migration Guide
Replace `Handle::weak_from_u128` with `weak_handle!` and a random UUID.
# Cold Specialization
## Objective
An ongoing part of our quest to retain everything in the render world,
cold-specialization aims to cache pipeline specialization so that
pipeline IDs can be recomputed only when necessary, rather than every
frame. This approach reduces redundant work in stable scenes, while
still accommodating scenarios in which materials, views, or visibility
might change, as well as unlocking future optimization work like
retaining render bins.
## Solution
Queue systems are split into a specialization system and queue system,
the former of which only runs when necessary to compute a new pipeline
id. Pipelines are invalidated using a combination of change detection
and ECS ticks.
### The difficulty with change detection
Detecting “what changed” can be tricky because pipeline specialization
depends not only on the entity’s components (e.g., mesh, material, etc.)
but also on which view (camera) it is rendering in. In other words, the
cache key for a given pipeline id is a view entity/render entity pair.
As such, it's not sufficient simply to react to change detection in
order to specialize -- an entity could currently be out of view or could
be rendered in the future in camera that is currently disabled or hasn't
spawned yet.
### Why ticks?
Ticks allow us to ensure correctness by allowing us to compare the last
time a view or entity was updated compared to the cached pipeline id.
This ensures that even if an entity was out of view or has never been
seen in a given camera before we can still correctly determine whether
it needs to be re-specialized or not.
## Testing
TODO: Tested a bunch of different examples, need to test more.
## Migration Guide
TODO
- `AssetEvents` has been moved into the `PostUpdate` schedule.
---------
Co-authored-by: Patrick Walton <pcwalton@mimiga.net>
*Occlusion culling* allows the GPU to skip the vertex and fragment
shading overhead for objects that can be quickly proved to be invisible
because they're behind other geometry. A depth prepass already
eliminates most fragment shading overhead for occluded objects, but the
vertex shading overhead, as well as the cost of testing and rejecting
fragments against the Z-buffer, is presently unavoidable for standard
meshes. We currently perform occlusion culling only for meshlets. But
other meshes, such as skinned meshes, can benefit from occlusion culling
too in order to avoid the transform and skinning overhead for unseen
meshes.
This commit adapts the same [*two-phase occlusion culling*] technique
that meshlets use to Bevy's standard 3D mesh pipeline when the new
`OcclusionCulling` component, as well as the `DepthPrepass` component,
are present on the camera. It has these steps:
1. *Early depth prepass*: We use the hierarchical Z-buffer from the
previous frame to cull meshes for the initial depth prepass, effectively
rendering only the meshes that were visible in the last frame.
2. *Early depth downsample*: We downsample the depth buffer to create
another hierarchical Z-buffer, this time with the current view
transform.
3. *Late depth prepass*: We use the new hierarchical Z-buffer to test
all meshes that weren't rendered in the early depth prepass. Any meshes
that pass this check are rendered.
4. *Late depth downsample*: Again, we downsample the depth buffer to
create a hierarchical Z-buffer in preparation for the early depth
prepass of the next frame. This step is done after all the rendering, in
order to account for custom phase items that might write to the depth
buffer.
Note that this patch has no effect on the per-mesh CPU overhead for
occluded objects, which remains high for a GPU-driven renderer due to
the lack of `cold-specialization` and retained bins. If
`cold-specialization` and retained bins weren't on the horizon, then a
more traditional approach like potentially visible sets (PVS) or low-res
CPU rendering would probably be more efficient than the GPU-driven
approach that this patch implements for most scenes. However, at this
point the amount of effort required to implement a PVS baking tool or a
low-res CPU renderer would probably be greater than landing
`cold-specialization` and retained bins, and the GPU driven approach is
the more modern one anyway. It does mean that the performance
improvements from occlusion culling as implemented in this patch *today*
are likely to be limited, because of the high CPU overhead for occluded
meshes.
Note also that this patch currently doesn't implement occlusion culling
for 2D objects or shadow maps. Those can be addressed in a follow-up.
Additionally, note that the techniques in this patch require compute
shaders, which excludes support for WebGL 2.
This PR is marked experimental because of known precision issues with
the downsampling approach when applied to non-power-of-two framebuffer
sizes (i.e. most of them). These precision issues can, in rare cases,
cause objects to be judged occluded that in fact are not. (I've never
seen this in practice, but I know it's possible; it tends to be likelier
to happen with small meshes.) As a follow-up to this patch, we desire to
switch to the [SPD-based hi-Z buffer shader from the Granite engine],
which doesn't suffer from these problems, at which point we should be
able to graduate this feature from experimental status. I opted not to
include that rewrite in this patch for two reasons: (1) @JMS55 is
planning on doing the rewrite to coincide with the new availability of
image atomic operations in Naga; (2) to reduce the scope of this patch.
A new example, `occlusion_culling`, has been added. It demonstrates
objects becoming quickly occluded and disoccluded by dynamic geometry
and shows the number of objects that are actually being rendered. Also,
a new `--occlusion-culling` switch has been added to `scene_viewer`, in
order to make it easy to test this patch with large scenes like Bistro.
[*two-phase occlusion culling*]:
https://medium.com/@mil_kru/two-pass-occlusion-culling-4100edcad501
[Aaltonen SIGGRAPH 2015]:
https://www.advances.realtimerendering.com/s2015/aaltonenhaar_siggraph2015_combined_final_footer_220dpi.pdf
[Some literature]:
https://gist.github.com/reduz/c5769d0e705d8ab7ac187d63be0099b5?permalink_comment_id=5040452#gistcomment-5040452
[SPD-based hi-Z buffer shader from the Granite engine]:
https://github.com/Themaister/Granite/blob/master/assets/shaders/post/hiz.comp
## Migration guide
* When enqueuing a custom mesh pipeline, work item buffers are now
created with
`bevy::render::batching::gpu_preprocessing::get_or_create_work_item_buffer`,
not `PreprocessWorkItemBuffers::new`. See the
`specialized_mesh_pipeline` example.
## Showcase
Occlusion culling example:

Bistro zoomed out, before occlusion culling:

Bistro zoomed out, after occlusion culling:

In this scene, occlusion culling reduces the number of meshes Bevy has
to render from 1591 to 585.
# Objective
- Contributes to #16877
## Solution
- Moved `hashbrown`, `foldhash`, and related types out of `bevy_utils`
and into `bevy_platform_support`
- Refactored the above to match the layout of these types in `std`.
- Updated crates as required.
## Testing
- CI
---
## Migration Guide
- The following items were moved out of `bevy_utils` and into
`bevy_platform_support::hash`:
- `FixedState`
- `DefaultHasher`
- `RandomState`
- `FixedHasher`
- `Hashed`
- `PassHash`
- `PassHasher`
- `NoOpHash`
- The following items were moved out of `bevy_utils` and into
`bevy_platform_support::collections`:
- `HashMap`
- `HashSet`
- `bevy_utils::hashbrown` has been removed. Instead, import from
`bevy_platform_support::collections` _or_ take a dependency on
`hashbrown` directly.
- `bevy_utils::Entry` has been removed. Instead, import from
`bevy_platform_support::collections::hash_map` or
`bevy_platform_support::collections::hash_set` as appropriate.
- All of the above equally apply to `bevy::utils` and
`bevy::platform_support`.
## Notes
- I left `PreHashMap`, `PreHashMapExt`, and `TypeIdMap` in `bevy_utils`
as they might be candidates for micro-crating. They can always be moved
into `bevy_platform_support` at a later date if desired.
# Objective
- Make the function signature for `ComponentHook` less verbose
## Solution
- Refactored `Entity`, `ComponentId`, and `Option<&Location>` into a new
`HookContext` struct.
## Testing
- CI
---
## Migration Guide
Update the function signatures for your component hooks to only take 2
arguments, `world` and `context`. Note that because `HookContext` is
plain data with all members public, you can use de-structuring to
simplify migration.
```rust
// Before
fn my_hook(
mut world: DeferredWorld,
entity: Entity,
component_id: ComponentId,
) { ... }
// After
fn my_hook(
mut world: DeferredWorld,
HookContext { entity, component_id, caller }: HookContext,
) { ... }
```
Likewise, if you were discarding certain parameters, you can use `..` in
the de-structuring:
```rust
// Before
fn my_hook(
mut world: DeferredWorld,
entity: Entity,
_: ComponentId,
) { ... }
// After
fn my_hook(
mut world: DeferredWorld,
HookContext { entity, .. }: HookContext,
) { ... }
```
# Objective
Fixes#14708
Also fixes some commands not updating tracked location.
## Solution
`ObserverTrigger` has a new `caller` field with the
`track_change_detection` feature;
hooks take an additional caller parameter (which is `Some(…)` or `None`
depending on the feature).
## Testing
See the new tests in `src/observer/mod.rs`
---
## Showcase
Observers now know from where they were triggered (if
`track_change_detection` is enabled):
```rust
world.observe(move |trigger: Trigger<OnAdd, Foo>| {
println!("Added Foo from {}", trigger.caller());
});
```
## Migration
- hooks now take an additional `Option<&'static Location>` argument
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
# Objective
`bevy_ecs`'s `system` module is something of a grab bag, and *very*
large. This is particularly true for the `system_param` module, which is
more than 2k lines long!
While it could be defensible to put `Res` and `ResMut` there (lol no
they're in change_detection.rs, obviously), it doesn't make any sense to
put the `Resource` trait there. This is confusing to navigate (and
painful to work on and review).
## Solution
- Create a root level `bevy_ecs/resource.rs` module to mirror
`bevy_ecs/component.rs`
- move the `Resource` trait to that module
- move the `Resource` derive macro to that module as well (Rust really
likes when you pun on the names of the derive macro and trait and put
them in the same path)
- fix all of the imports
## Notes to reviewers
- We could probably move more stuff into here, but I wanted to keep this
PR as small as possible given the absurd level of import changes.
- This PR is ground work for my upcoming attempts to store resource data
on components (resources-as-entities). Splitting this code out will make
the work and review a bit easier, and is the sort of overdue refactor
that's good to do as part of more meaningful work.
## Testing
cargo build works!
## Migration Guide
`bevy_ecs::system::Resource` has been moved to
`bevy_ecs::resource::Resource`.
Fixes#17412
## Objective
`Parent` uses the "has a X" naming convention. There is increasing
sentiment that we should use the "is a X" naming convention for
relationships (following #17398). This leaves `Children` as-is because
there is prevailing sentiment that `Children` is clearer than `ParentOf`
in many cases (especially when treating it like a collection).
This renames `Parent` to `ChildOf`.
This is just the implementation PR. To discuss the path forward, do so
in #17412.
## Migration Guide
- The `Parent` component has been renamed to `ChildOf`.
# Objective
The existing `RelationshipSourceCollection` uses `Vec` as the only
possible backing for our relationships. While a reasonable choice,
benchmarking use cases might reveal that a different data type is better
or faster.
For example:
- Not all relationships require a stable ordering between the
relationship sources (i.e. children). In cases where we a) have many
such relations and b) don't care about the ordering between them, a hash
set is likely a better datastructure than a `Vec`.
- The number of children-like entities may be small on average, and a
`smallvec` may be faster
## Solution
- Implement `RelationshipSourceCollection` for `EntityHashSet`, our
custom entity-optimized `HashSet`.
-~~Implement `DoubleEndedIterator` for `EntityHashSet` to make things
compile.~~
- This implementation was cursed and very surprising.
- Instead, by moving the iterator type on `RelationshipSourceCollection`
from an erased RPTIT to an explicit associated type we can add a trait
bound on the offending methods!
- Implement `RelationshipSourceCollection` for `SmallVec`
## Testing
I've added a pair of new tests to make sure this pattern compiles
successfully in practice!
## Migration Guide
`EntityHashSet` and `EntityHashMap` are no longer re-exported in
`bevy_ecs::entity` directly. If you were not using `bevy_ecs` / `bevy`'s
`prelude`, you can access them through their now-public modules,
`hash_set` and `hash_map` instead.
## Notes to reviewers
The `EntityHashSet::Iter` type needs to be public for this impl to be
allowed. I initially renamed it to something that wasn't ambiguous and
re-exported it, but as @Victoronz pointed out, that was somewhat
unidiomatic.
In
1a8564898f,
I instead made the `entity_hash_set` public (and its `entity_hash_set`)
sister public, and removed the re-export. I prefer this design (give me
module docs please), but it leads to a lot of churn in this PR.
Let me know which you'd prefer, and if you'd like me to split that
change out into its own micro PR.
This adds support for one-to-many non-fragmenting relationships (with
planned paths for fragmenting and non-fragmenting many-to-many
relationships). "Non-fragmenting" means that entities with the same
relationship type, but different relationship targets, are not forced
into separate tables (which would cause "table fragmentation").
Functionally, this fills a similar niche as the current Parent/Children
system. The biggest differences are:
1. Relationships have simpler internals and significantly improved
performance and UX. Commands and specialized APIs are no longer
necessary to keep everything in sync. Just spawn entities with the
relationship components you want and everything "just works".
2. Relationships are generalized. Bevy can provide additional built in
relationships, and users can define their own.
**REQUEST TO REVIEWERS**: _please don't leave top level comments and
instead comment on specific lines of code. That way we can take
advantage of threaded discussions. Also dont leave comments simply
pointing out CI failures as I can read those just fine._
## Built on top of what we have
Relationships are implemented on top of the Bevy ECS features we already
have: components, immutability, and hooks. This makes them immediately
compatible with all of our existing (and future) APIs for querying,
spawning, removing, scenes, reflection, etc. The fewer specialized APIs
we need to build, maintain, and teach, the better.
## Why focus on one-to-many non-fragmenting first?
1. This allows us to improve Parent/Children relationships immediately,
in a way that is reasonably uncontroversial. Switching our hierarchy to
fragmenting relationships would have significant performance
implications. ~~Flecs is heavily considering a switch to non-fragmenting
relations after careful considerations of the performance tradeoffs.~~
_(Correction from @SanderMertens: Flecs is implementing non-fragmenting
storage specialized for asset hierarchies, where asset hierarchies are
many instances of small trees that have a well defined structure)_
2. Adding generalized one-to-many relationships is currently a priority
for the [Next Generation Scene / UI
effort](https://github.com/bevyengine/bevy/discussions/14437).
Specifically, we're interested in building reactions and observers on
top.
## The changes
This PR does the following:
1. Adds a generic one-to-many Relationship system
3. Ports the existing Parent/Children system to Relationships, which now
lives in `bevy_ecs::hierarchy`. The old `bevy_hierarchy` crate has been
removed.
4. Adds on_despawn component hooks
5. Relationships can opt-in to "despawn descendants" behavior, meaning
that the entire relationship hierarchy is despawned when
`entity.despawn()` is called. The built in Parent/Children hierarchies
enable this behavior, and `entity.despawn_recursive()` has been removed.
6. `world.spawn` now applies commands after spawning. This ensures that
relationship bookkeeping happens immediately and removes the need to
manually flush. This is in line with the equivalent behaviors recently
added to the other APIs (ex: insert).
7. Removes the ValidParentCheckPlugin (system-driven / poll based) in
favor of a `validate_parent_has_component` hook.
## Using Relationships
The `Relationship` trait looks like this:
```rust
pub trait Relationship: Component + Sized {
type RelationshipSources: RelationshipSources<Relationship = Self>;
fn get(&self) -> Entity;
fn from(entity: Entity) -> Self;
}
```
A relationship is a component that:
1. Is a simple wrapper over a "target" Entity.
2. Has a corresponding `RelationshipSources` component, which is a
simple wrapper over a collection of entities. Every "target entity"
targeted by a "source entity" with a `Relationship` has a
`RelationshipSources` component, which contains every "source entity"
that targets it.
For example, the `Parent` component (as it currently exists in Bevy) is
the `Relationship` component and the entity containing the Parent is the
"source entity". The entity _inside_ the `Parent(Entity)` component is
the "target entity". And that target entity has a `Children` component
(which implements `RelationshipSources`).
In practice, the Parent/Children relationship looks like this:
```rust
#[derive(Relationship)]
#[relationship(relationship_sources = Children)]
pub struct Parent(pub Entity);
#[derive(RelationshipSources)]
#[relationship_sources(relationship = Parent)]
pub struct Children(Vec<Entity>);
```
The Relationship and RelationshipSources derives automatically implement
Component with the relevant configuration (namely, the hooks necessary
to keep everything in sync).
The most direct way to add relationships is to spawn entities with
relationship components:
```rust
let a = world.spawn_empty().id();
let b = world.spawn(Parent(a)).id();
assert_eq!(world.entity(a).get::<Children>().unwrap(), &[b]);
```
There are also convenience APIs for spawning more than one entity with
the same relationship:
```rust
world.spawn_empty().with_related::<Children>(|s| {
s.spawn_empty();
s.spawn_empty();
})
```
The existing `with_children` API is now a simpler wrapper over
`with_related`. This makes this change largely non-breaking for existing
spawn patterns.
```rust
world.spawn_empty().with_children(|s| {
s.spawn_empty();
s.spawn_empty();
})
```
There are also other relationship APIs, such as `add_related` and
`despawn_related`.
## Automatic recursive despawn via the new on_despawn hook
`RelationshipSources` can opt-in to "despawn descendants" behavior,
which will despawn all related entities in the relationship hierarchy:
```rust
#[derive(RelationshipSources)]
#[relationship_sources(relationship = Parent, despawn_descendants)]
pub struct Children(Vec<Entity>);
```
This means that `entity.despawn_recursive()` is no longer required.
Instead, just use `entity.despawn()` and the relevant related entities
will also be despawned.
To despawn an entity _without_ despawning its parent/child descendants,
you should remove the `Children` component first, which will also remove
the related `Parent` components:
```rust
entity
.remove::<Children>()
.despawn()
```
This builds on the on_despawn hook introduced in this PR, which is fired
when an entity is despawned (before other hooks).
## Relationships are the source of truth
`Relationship` is the _single_ source of truth component.
`RelationshipSources` is merely a reflection of what all the
`Relationship` components say. By embracing this, we are able to
significantly improve the performance of the system as a whole. We can
rely on component lifecycles to protect us against duplicates, rather
than needing to scan at runtime to ensure entities don't already exist
(which results in quadratic runtime). A single source of truth gives us
constant-time inserts. This does mean that we cannot directly spawn
populated `Children` components (or directly add or remove entities from
those components). I personally think this is a worthwhile tradeoff,
both because it makes the performance much better _and_ because it means
theres exactly one way to do things (which is a philosophy we try to
employ for Bevy APIs).
As an aside: treating both sides of the relationship as "equivalent
source of truth relations" does enable building simple and flexible
many-to-many relationships. But this introduces an _inherent_ need to
scan (or hash) to protect against duplicates.
[`evergreen_relations`](https://github.com/EvergreenNest/evergreen_relations)
has a very nice implementation of the "symmetrical many-to-many"
approach. Unfortunately I think the performance issues inherent to that
approach make it a poor choice for Bevy's default relationship system.
## Followup Work
* Discuss renaming `Parent` to `ChildOf`. I refrained from doing that in
this PR to keep the diff reasonable, but I'm personally biased toward
this change (and using that naming pattern generally for relationships).
* [Improved spawning
ergonomics](https://github.com/bevyengine/bevy/discussions/16920)
* Consider adding relationship observers/triggers for "relationship
targets" whenever a source is added or removed. This would replace the
current "hierarchy events" system, which is unused upstream but may have
existing users downstream. I think triggers are the better fit for this
than a buffered event queue, and would prefer not to add that back.
* Fragmenting relations: My current idea hinges on the introduction of
"value components" (aka: components whose type _and_ value determines
their ComponentId, via something like Hashing / PartialEq). By labeling
a Relationship component such as `ChildOf(Entity)` as a "value
component", `ChildOf(e1)` and `ChildOf(e2)` would be considered
"different components". This makes the transition between fragmenting
and non-fragmenting a single flag, and everything else continues to work
as expected.
* Many-to-many support
* Non-fragmenting: We can expand Relationship to be a list of entities
instead of a single entity. I have largely already written the code for
this.
* Fragmenting: With the "value component" impl mentioned above, we get
many-to-many support "for free", as it would allow inserting multiple
copies of a Relationship component with different target entities.
Fixes#3742 (If this PR is merged, I think we should open more targeted
followup issues for the work above, with a fresh tracking issue free of
the large amount of less-directed historical context)
Fixes#17301Fixes#12235Fixes#15299Fixes#15308
## Migration Guide
* Replace `ChildBuilder` with `ChildSpawnerCommands`.
* Replace calls to `.set_parent(parent_id)` with
`.insert(Parent(parent_id))`.
* Replace calls to `.replace_children()` with `.remove::<Children>()`
followed by `.add_children()`. Note that you'll need to manually despawn
any children that are not carried over.
* Replace calls to `.despawn_recursive()` with `.despawn()`.
* Replace calls to `.despawn_descendants()` with
`.despawn_related::<Children>()`.
* If you have any calls to `.despawn()` which depend on the children
being preserved, you'll need to remove the `Children` component first.
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
This commit allows Bevy to use `multi_draw_indirect_count` for drawing
meshes. The `multi_draw_indirect_count` feature works just like
`multi_draw_indirect`, but it takes the number of indirect parameters
from a GPU buffer rather than specifying it on the CPU.
Currently, the CPU constructs the list of indirect draw parameters with
the instance count for each batch set to zero, uploads the resulting
buffer to the GPU, and dispatches a compute shader that bumps the
instance count for each mesh that survives culling. Unfortunately, this
is inefficient when we support `multi_draw_indirect_count`. Draw
commands corresponding to meshes for which all instances were culled
will remain present in the list when calling
`multi_draw_indirect_count`, causing overhead. Proper use of
`multi_draw_indirect_count` requires eliminating these empty draw
commands.
To address this inefficiency, this PR makes Bevy fully construct the
indirect draw commands on the GPU instead of on the CPU. Instead of
writing instance counts to the draw command buffer, the mesh
preprocessing shader now writes them to a separate *indirect metadata
buffer*. A second compute dispatch known as the *build indirect
parameters* shader runs after mesh preprocessing and converts the
indirect draw metadata into actual indirect draw commands for the GPU.
The build indirect parameters shader operates on a batch at a time,
rather than an instance at a time, and as such each thread writes only 0
or 1 indirect draw parameters, simplifying the current logic in
`mesh_preprocessing`, which currently has to have special cases for the
first mesh in each batch. The build indirect parameters shader emits
draw commands in a tightly packed manner, enabling maximally efficient
use of `multi_draw_indirect_count`.
Along the way, this patch switches mesh preprocessing to dispatch one
compute invocation per render phase per view, instead of dispatching one
compute invocation per view. This is preparation for two-phase occlusion
culling, in which we will have two mesh preprocessing stages. In that
scenario, the first mesh preprocessing stage must only process opaque
and alpha tested objects, so the work items must be separated into those
that are opaque or alpha tested and those that aren't. Thus this PR
splits out the work items into a separate buffer for each phase. As this
patch rewrites so much of the mesh preprocessing infrastructure, it was
simpler to just fold the change into this patch instead of deferring it
to the forthcoming occlusion culling PR.
Finally, this patch changes mesh preprocessing so that it runs
separately for indexed and non-indexed meshes. This is because draw
commands for indexed and non-indexed meshes have different sizes and
layouts. *The existing code is actually broken for non-indexed meshes*,
as it attempts to overlay the indirect parameters for non-indexed meshes
on top of those for indexed meshes. Consequently, right now the
parameters will be read incorrectly when multiple non-indexed meshes are
multi-drawn together. *This is a bug fix* and, as with the change to
dispatch phases separately noted above, was easiest to include in this
patch as opposed to separately.
## Migration Guide
* Systems that add custom phase items now need to populate the indirect
drawing-related buffers. See the `specialized_mesh_pipeline` example for
an example of how this is done.
We won't be able to retain render phases from frame to frame if the keys
are unstable. It's not as simple as simply keying off the main world
entity, however, because some main world entities extract to multiple
render world entities. For example, directional lights extract to
multiple shadow cascades, and point lights extract to one view per
cubemap face. Therefore, we key off a new type, `RetainedViewEntity`,
which contains the main entity plus a *subview ID*.
This is part of the preparation for retained bins.
---------
Co-authored-by: ickshonpe <david.curthoys@googlemail.com>
# Objective
Many instances of `clippy::too_many_arguments` linting happen to be on
systems - functions which we don't call manually, and thus there's not
much reason to worry about the argument count.
## Solution
Allow `clippy::too_many_arguments` globally, and remove all lint
attributes related to it.
# Objective
In my crusade to give every lint attribute a reason, it appears I got
too complacent and copy-pasted this expect onto non-system functions.
## Solution
Fix up the reason on those non-system functions
## Testing
N/A
# Objective
- https://github.com/bevyengine/bevy/issues/17111
## Solution
Set the `clippy::allow_attributes` and
`clippy::allow_attributes_without_reason` lints to `deny`, and bring
`bevy_render` in line with the new restrictions.
## Testing
`cargo clippy` and `cargo test --package bevy_render` were run, and no
errors were encountered.
# Objective
- Contributes to #11478
## Solution
- Made `bevy_utils::tracing` `doc(hidden)`
- Re-exported `tracing` from `bevy_log` for end-users
- Added `tracing` directly to crates that need it.
## Testing
- CI
---
## Migration Guide
If you were importing `tracing` via `bevy::utils::tracing`, instead use
`bevy::log::tracing`. Note that many items within `tracing` are also
directly re-exported from `bevy::log` as well, so you may only need
`bevy::log` for the most common items (e.g., `warn!`, `trace!`, etc.).
This also applies to the `log_once!` family of macros.
## Notes
- While this doesn't reduce the line-count in `bevy_utils`, it further
decouples the internal crates from `bevy_utils`, making its eventual
removal more feasible in the future.
- I have just imported `tracing` as we do for all dependencies. However,
a workspace dependency may be more appropriate for version management.
Derived `Default` for all public unit structs that already derive from
`Component`. This allows them to be used more easily as required
components.
To avoid clutter in tests/examples, only public components were
affected, but this could easily be expanded to affect all unit
components.
Fixes#17052.
# Objective
- Fixes https://github.com/bevyengine/bevy/issues/16556
- Closes https://github.com/bevyengine/bevy/issues/11807
## Solution
- Simplify custom projections by using a single source of truth -
`Projection`, removing all existing generic systems and types.
- Existing perspective and orthographic structs are no longer components
- I could dissolve these to simplify further, but keeping them around
was the fast way to implement this.
- Instead of generics, introduce a third variant, with a trait object.
- Do an object safety dance with an intermediate trait to allow cloning
boxed camera projections. This is a normal rust polymorphism papercut.
You can do this with a crate but a manual impl is short and sweet.
## Testing
- Added a custom projection example
---
## Showcase
- Custom projections and projection handling has been simplified.
- Projection systems are no longer generic, with the potential for many
different projection components on the same camera.
- Instead `Projection` is now the single source of truth for camera
projections, and is the only projection component.
- Custom projections are still supported, and can be constructed with
`Projection::custom()`.
## Migration Guide
- `PerspectiveProjection` and `OrthographicProjection` are no longer
components. Use `Projection` instead.
- Custom projections should no longer be inserted as a component.
Instead, simply set the custom projection as a value of `Projection`
with `Projection::custom()`.
# Objective
Fixes#17024
## Solution
## Testing
By adding
```
if let Some(mut cmd) = commands.get_entity( *equipment_link_node ){
cmd.insert(Visibility::Inherited); // a hack for now
}
```
in my build after .set_parent() , this fixes the issue. This is why i
think that this change will fix the issue. Unfortunately i was not able
to test the Changed (parent ) , this actual code change, because no
matter how i 'patch', it breaks my project. I got super close but still
had 23 errors due to Reflect being angry.
---
# Objective
Fixes#16683
## Solution
Make all fields ine `RawHandleWrapper` private.
## Testing
- CI
- `cargo clippy`
- The lightmaps example
---
## Migration Guide
The `window_handle` and `dispay_handle` fields on `RawHandleWrapper` are
no longer public. Use the newly added getters and setters to manipulate
them instead.
# Objective
Fixes#16104
## Solution
I removed all instances of `:?` and put them back one by one where it
caused an error.
I removed some bevy_utils helper functions that were only used in 2
places and don't add value. See: #11478
## Testing
CI should catch the mistakes
## Migration Guide
`bevy::utils::{dbg,info,warn,error}` were removed. Use
`bevy::utils::tracing::{debug,info,warn,error}` instead.
---------
Co-authored-by: SpecificProtagonist <vincentjunge@posteo.net>
# Objective
- Fixes#16892
## Solution
- Removed `TypeRegistryPlugin` (`Name` is now automatically registered
with a default `App`)
- Moved `TaskPoolPlugin` to `bevy_app`
- Moved `FrameCountPlugin` to `bevy_diagnostic`
- Deleted now-empty `bevy_core`
## Testing
- CI
## Migration Guide
- `TypeRegistryPlugin` no longer exists. If you can't use a default
`App` but still need `Name` registered, do so manually with
`app.register_type::<Name>()`.
- References to `TaskPoolPlugin` and associated types will need to
import it from `bevy_app` instead of `bevy_core`
- References to `FrameCountPlugin` and associated types will need to
import it from `bevy_diagnostic` instead of `bevy_core`
## Notes
This strategy was agreed upon by Cart and several other members in
[Discord](https://discord.com/channels/691052431525675048/692572690833473578/1319137218312278077).
# Objective
I have something of a niche use case. I have a camera rendering pixel
art with a scale factor set, and another camera that renders to an
off-screen texture which is supposed to match the main camera exactly.
However, when computing camera target info, Bevy [hardcodes a scale
factor of
1.0](116c2b02fe/crates/bevy_render/src/camera/camera.rs (L828))
for image targets which means that my main camera and my image target
camera get different `OrthographicProjections` calculated.
## Solution
This PR adds an `ImageRenderTarget` struct which allows scale factors to
be specified.
## Testing
I tested the affected examples on macOS and they still work. This is an
additive change and should not break any existing code, apart from what
is trivially fixable by following compiler error messages.
---
## Migration Guide
`RenderTarget::Image` now takes an `ImageRenderTarget` instead of a
`Handle<Image>`. You can call `handle.into()` to construct an
`ImageRenderTarget` using the same settings as before.
# Objective
When preparing `GpuImage`s, we currently discard the
`depth_or_array_layers` of the `Image`'s size by converting it into a
`UVec2`.
Fixes#16715.
## Solution
Change `GpuImage::size` to `Extent3d`, and just pass that through when
creating `GpuImage`s.
Also copy the `aspect_ratio`, and `size` (now `size_2d` for
disambiguation from the field) functions from `Image` to `GpuImage` for
ease of use with 2D textures.
I originally copied all size-related functions (like `width`, and
`height`), but i think they are unnecessary considering how visible the
`size` field on `GpuImage` is compared to `Image`.
## Testing
Tested via `cargo r -p ci` for everything except docs, when generating
docs it keeps spitting out a ton of
```
error[E0554]: `#![feature]` may not be used on the stable release channel
--> crates/bevy_dylib/src/lib.rs:1:21
|
1 | #![cfg_attr(docsrs, feature(doc_auto_cfg))]
|
```
Not sure why this is happening, but it also happens without my changes,
so it's almost certainly some strange issue specific to my machine.
## Migration Guide
- `GpuImage::size` is now an `Extent3d`. To easily get 2D size, use
`size_2d()`.
Currently, `check_visibility` is parameterized over a query filter that
specifies the type of potentially-visible object. This has the
unfortunate side effect that we need a separate system,
`mark_view_visibility_as_changed_if_necessary`, to trigger view
visibility change detection. That system is quite slow because it must
iterate sequentially over all entities in the scene.
This PR moves the query filter from `check_visibility` to a new
component, `VisibilityClass`. `VisibilityClass` stores a list of type
IDs, each corresponding to one of the query filters we used to use.
Because `check_visibility` is no longer specialized to the query filter
at the type level, Bevy now only needs to invoke it once, leading to
better performance as `check_visibility` can do change detection on the
fly rather than delegating it to a separate system.
This commit also has ergonomic improvements, as there's no need for
applications that want to add their own custom renderable components to
add specializations of the `check_visibility` system to the schedule.
Instead, they only need to ensure that the `ViewVisibility` component is
properly kept up to date. The recommended way to do this, and the way
that's demonstrated in the `custom_phase_item` and
`specialized_mesh_pipeline` examples, is to make `ViewVisibility` a
required component and to add the type ID to it in a component add hook.
This patch does this for `Mesh3d`, `Mesh2d`, `Sprite`, `Light`, and
`Node`, which means that most app code doesn't need to change at all.
Note that, although this patch has a large impact on the performance of
visibility determination, it doesn't actually improve the end-to-end
frame time of `many_cubes`. That's because the render world was already
effectively hiding the latency from
`mark_view_visibility_as_changed_if_necessary`. This patch is, however,
necessary for *further* improvements to `many_cubes` performance.
`many_cubes` trace before:

`many_cubes` trace after:

## Migration Guide
* `check_visibility` no longer takes a `QueryFilter`, and there's no
need to add it manually to your app schedule anymore for custom
rendering items. Instead, entities with custom renderable components
should add the appropriate type IDs to `VisibilityClass`. See
`custom_phase_item` for an example.
This patch replaces the undocumented `NoGpuCulling` component with a new
component, `NoIndirectDrawing`, effectively turning indirect drawing on
by default. Indirect mode is needed for the recently-landed multidraw
feature (#16427). Since multidraw is such a win for performance, when
that feature is supported the small performance tax that indirect mode
incurs is virtually always worth paying.
To ensure that custom drawing code such as that in the
`custom_shader_instancing` example continues to function, this commit
additionally makes GPU culling take the `NoFrustumCulling` component
into account.
This PR is an alternative to #16670 that doesn't break the
`custom_shader_instancing` example. **PR #16755 should land first in
order to avoid breaking deferred rendering, as multidraw currently
breaks it**.
## Migration Guide
* Indirect drawing (GPU culling) is now enabled by default, so the
`GpuCulling` component is no longer available. To disable indirect mode,
which may be useful with custom render nodes, add the new
`NoIndirectDrawing` component to your camera.
Updating dependencies; adopted version of #15696. (Supercedes #15696.)
Long answer: hashbrown is no longer using ahash by default, meaning that
we can't use the default-hasher methods with ahasher. So, we have to use
the longer-winded versions instead. This takes the opportunity to also
switch our default hasher as well, but without actually enabling the
default-hasher feature for hashbrown, meaning that we'll be able to
change our hasher more easily at the cost of all of these method calls
being obnoxious forever.
One large change from 0.15 is that `insert_unique_unchecked` is now
`unsafe`, and for cases where unsafe code was denied at the crate level,
I replaced it with `insert`.
## Migration Guide
`bevy_utils` has updated its version of `hashbrown` to 0.15 and now
defaults to `foldhash` instead of `ahash`. This means that if you've
hard-coded your hasher to `bevy_utils::AHasher` or separately used the
`ahash` crate in your code, you may need to switch to `foldhash` to
ensure that everything works like it does in Bevy.
This commit moves the front end of the rendering pipeline to a retained
model when GPU preprocessing is in use (i.e. by default, except in
constrained environments). `RenderMeshInstance` and `MeshUniformData`
are stored from frame to frame and are updated only for the entities
that changed state. This was rather tricky and requires some careful
surgery to keep the data valid in the case of removals.
This patch is built on top of Bevy's change detection. Generally, this
worked, except that `ViewVisibility` isn't currently properly tracked.
Therefore, this commit adds proper change tracking for `ViewVisibility`.
Doing this required adding a new system that runs after all
`check_visibility` invocations, as no single `check_visibility`
invocation has enough global information to detect changes.
On the Bistro exterior scene, with all textures forced to opaque, this
patch improves steady-state `extract_meshes_for_gpu_building` from
93.8us to 34.5us and steady-state `collect_meshes_for_gpu_building` from
195.7us to 4.28us. Altogether this constitutes an improvement from 290us
to 38us, which is a 7.46x speedup.


This patch is only lightly tested and shouldn't land before 0.15 is
released anyway, so I'm releasing it as a draft.
# Objective
- Required by #16622 due to differing implementations of `System` by
`FunctionSystem` and `ExclusiveFunctionSystem`.
- Optimize the memory usage of instances of `apply_deferred` in system
schedules.
## Solution
By changing `apply_deferred` from being an ordinary system that ends up
as an `ExclusiveFunctionSystem`, and instead into a ZST struct that
implements `System` manually, we save ~320 bytes per instance of
`apply_deferred` in any schedule.
## Testing
- All current tests pass.
---
## Migration Guide
- If you were previously calling the special `apply_deferred` system via
`apply_deferred(world)`, don't.
PR #15164 made Bevy consider the center of the mesh to be the center of
the axis-aligned bounding box (AABB). Unfortunately, this breaks
crossfading in many cases. LODs may have different AABBs and so the
center of the AABB may differ for different LODs of the same mesh. The
crossfading, however, relies on all LODs having *precisely* the same
position.
To address this problem, this PR adds a new field, `use_aabb`, to
`VisibilityRange`, which makes the AABB center point behavior opt-in.
@BenjaminBrienen first noticed this issue when reviewing PR #16286. That
PR contains a video showing the effects of this regression on the
`visibility_range` example. This commit fixes that example.
## Migration Guide
* The `VisibilityRange` component now has an extra field, `use_aabb`.
Generally, you can safely set it to false.
We have an early-out to avoid updating `RenderVisibilityRanges` when a
`VisibilityRange` component is *modified*, but not when one is
*removed*. This means that removing `VisibilityRange` from an entity
might not update the rendering.
This PR fixes the issue by adding a check for removed
`VisibilityRange`s.
# Objective
Fixes#15940
## Solution
Remove the `pub use` and fix the compile errors.
Make `bevy_image` available as `bevy::image`.
## Testing
Feature Frenzy would be good here! Maybe I'll learn how to use it if I
have some time this weekend, or maybe a reviewer can use it.
## Migration Guide
Use `bevy_image` instead of `bevy_render::texture` items.
---------
Co-authored-by: chompaa <antony.m.3012@gmail.com>
Co-authored-by: Carter Anderson <mcanders1@gmail.com>
# Objective
- wgpu 0.20 made workgroup vars stop being zero-init by default. this
broke some applications (cough foresight cough) and now we workaround
it. wgpu exposes a compilation option that zero initializes workgroup
memory by default, but bevy does not expose it.
## Solution
- expose the compilation option wgpu gives us
## Testing
- ran examples: 3d_scene, compute_shader_game_of_life, gpu_readback,
lines, specialized_mesh_pipeline. they all work
- confirmed fix for our own problems
---
</details>
## Migration Guide
- add `zero_initialize_workgroup_memory: false,` to
`ComputePipelineDescriptor` or `RenderPipelineDescriptor` structs to
preserve 0.14 functionality, add `zero_initialize_workgroup_memory:
true,` to restore bevy 0.13 functionality.
# Objective
#14273 changed `Msaa` to be a component rather than a resource. However,
the documentation still says that it is a resource. This tripped me up
during migration to 0.15 until I looked at the type definition.
Additionally, the docs have some unnecessary repetition and some grammar
mistakes, and they don't link to camera documentation.
## Solution
Fix up the docs!
# Objective
- Fixes#16122
When the wayland feature is not enabled, xwayland is used on wayland.
Nvidia drivers are somewhat bugged on linux and return outdated surfaces
on xwayland for seemingly no reason. Oftentimes at startup we get into
an infine loop where the surface is permanently outdated and nothing (or
sometimes only the first frame) is drawn on the screen.
## Solution
After experimenting I found that we can safely call configure again and
the issue seems to resolve itsef. After this change I couldn't reproduce
the original issue after many tries. More testing is probably needed
though.
The main issue is that `get_current_texture` fails sometimes because the
surface remains outdated even after configuring. It would be better to
just properly handle and never panic when `get_current_texture` fails.
This way we always call configure when outdated and bail when getting
the swapchain fails instead of crashing. The number of special cases is
also reduced.
## Testing
I tested the example "rotation" manually by trying to move around.
It works with X11 and Xwayland and the non panicing code paths didn't
change so other platforms aren't affected.