Commit graph

79 commits

Author SHA1 Message Date
Benjamin Brienen
40640fdf42
Don't reëxport bevy_image from bevy_render (#16163)
# 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>
2024-11-10 06:54:38 +00:00
atlv
c29e67153b
Expose Pipeline Compilation Zero Initialize Workgroup Memory Option (#16301)
# 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.
2024-11-08 21:42:37 +00:00
Joona Aalto
c1a4b82762
Revert default mesh materials (#15930)
# Objective

Closes #15799.

Many rendering people and maintainers are in favor of reverting default
mesh materials added in #15524, especially as the migration to required
component is already large and heavily breaking.

## Solution

Revert default mesh materials, and adjust docs accordingly.

- Remove `extract_default_materials`
- Remove `clear_material_instances`, and move the logic back into
`extract_mesh_materials`
- Remove `HasMaterial2d` and `HasMaterial3d`
- Change default material handles back to pink instead of white
- 2D uses `Color::srgb(1.0, 0.0, 1.0)`, while 3D uses `Color::srgb(1.0,
0.0, 0.5)`. Not sure if this is intended.

There is now no indication at all about missing materials for `Mesh2d`
and `Mesh3d`. Having a mesh without a material renders nothing.

## Testing

I ran `2d_shapes`, `mesh2d_manual`, and `3d_shapes`, with and without
mesh material components.
2024-10-15 19:47:40 +00:00
Rob Parrett
9dd6f42b32
Alternative fix for mesh2d_manual example (#15883)
# Objective

Fixes #15847

Alternative to #15862. Would appreciate a rendering person signaling
preference for one or the other.

## Solution

Partially revert the changes made to this example in #15524.

Add comment explaining that the non-usage of the built-in color vertex
attribute is intentional.

## Testing

`cargo run --example mesh2d_manual`
2024-10-14 01:02:23 +00:00
NiseVoid
bdd0af6bfb
Deprecate SpatialBundle (#15830)
# Objective

- Required components replace bundles, but `SpatialBundle` is yet to be
deprecated

## Solution

- Deprecate `SpatialBundle`
- Insert `Transform` and `Visibility` instead in examples using it
- In `spawn` or `insert` inserting a default `Transform` or `Visibility`
with component already requiring either, remove those components from
the tuple

## Testing

- Did you test these changes? If so, how?
Yes, I ran the examples I changed and tests
- Are there any parts that need more testing?
The `gamepad_viewer` and and `custom_shader_instancing` examples don't
work as intended due to entirely unrelated code, didn't check main.
- How can other people (reviewers) test your changes? Is there anything
specific they need to know?
Run examples, or just check that all spawned values are identical
- If relevant, what platforms did you test these changes on, and are
there any important ones you can't test?
Linux, wayland trough x11 (cause that's the default feature)

---

## Migration Guide

`SpatialBundle` is now deprecated, insert `Transform` and `Visibility`
instead which will automatically insert all other components that were
in the bundle. If you do not specify these values and any other
components in your `spawn`/`insert` call already requires either of
these components you can leave that one out.

before:
```rust
commands.spawn(SpatialBundle::default());
```

after:
```rust
commands.spawn((Transform::default(), Visibility::default());
```
2024-10-13 17:28:22 +00:00
charlotte
dd812b3e49
Type safe retained render world (#15756)
# Objective

In the Render World, there are a number of collections that are derived
from Main World entities and are used to drive rendering. The most
notable are:
- `VisibleEntities`, which is generated in the `check_visibility` system
and contains visible entities for a view.
- `ExtractedInstances`, which maps entity ids to asset ids.

In the old model, these collections were trivially kept in sync -- any
extracted phase item could look itself up because the render entity id
was guaranteed to always match the corresponding main world id.

After #15320, this became much more complicated, and was leading to a
number of subtle bugs in the Render World. The main rendering systems,
i.e. `queue_material_meshes` and `queue_material2d_meshes`, follow a
similar pattern:

```rust
for visible_entity in visible_entities.iter::<With<Mesh2d>>() {
    let Some(mesh_instance) = render_mesh_instances.get_mut(visible_entity) else {
        continue;
    };
            
    // Look some more stuff up and specialize the pipeline...
            
    let bin_key = Opaque2dBinKey {
        pipeline: pipeline_id,
        draw_function: draw_opaque_2d,
        asset_id: mesh_instance.mesh_asset_id.into(),
        material_bind_group_id: material_2d.get_bind_group_id().0,
    };
    opaque_phase.add(
        bin_key,
        *visible_entity,
        BinnedRenderPhaseType::mesh(mesh_instance.automatic_batching),
    );
}
```

In this case, `visible_entities` and `render_mesh_instances` are both
collections that are created and keyed by Main World entity ids, and so
this lookup happens to work by coincidence. However, there is a major
unintentional bug here: namely, because `visible_entities` is a
collection of Main World ids, the phase item being queued is created
with a Main World id rather than its correct Render World id.

This happens to not break mesh rendering because the render commands
used for drawing meshes do not access the `ItemQuery` parameter, but
demonstrates the confusion that is now possible: our UI phase items are
correctly being queued with Render World ids while our meshes aren't.

Additionally, this makes it very easy and error prone to use the wrong
entity id to look up things like assets. For example, if instead we
ignored visibility checks and queued our meshes via a query, we'd have
to be extra careful to use `&MainEntity` instead of the natural
`Entity`.

## Solution

Make all collections that are derived from Main World data use
`MainEntity` as their key, to ensure type safety and avoid accidentally
looking up data with the wrong entity id:

```rust
pub type MainEntityHashMap<V> = hashbrown::HashMap<MainEntity, V, EntityHash>;
```

Additionally, we make all `PhaseItem` be able to provide both their Main
and Render World ids, to allow render phase implementors maximum
flexibility as to what id should be used to look up data.

You can think of this like tracking at the type level whether something
in the Render World should use it's "primary key", i.e. entity id, or
needs to use a foreign key, i.e. `MainEntity`.

## Testing

##### TODO:

This will require extensive testing to make sure things didn't break!
Additionally, some extraction logic has become more complicated and
needs to be checked for regressions.

## Migration Guide

With the advent of the retained render world, collections that contain
references to `Entity` that are extracted into the render world have
been changed to contain `MainEntity` in order to prevent errors where a
render world entity id is used to look up an item by accident. Custom
rendering code may need to be changed to query for `&MainEntity` in
order to look up the correct item from such a collection. Additionally,
users who implement their own extraction logic for collections of main
world entity should strongly consider extracting into a different
collection that uses `MainEntity` as a key.

Additionally, render phases now require specifying both the `Entity` and
`MainEntity` for a given `PhaseItem`. Custom render phases should ensure
`MainEntity` is available when queuing a phase item.
2024-10-10 18:47:04 +00:00
Joona Aalto
25bfa80e60
Migrate cameras to required components (#15641)
# Objective

Yet another PR for migrating stuff to required components. This time,
cameras!

## Solution

As per the [selected
proposal](https://hackmd.io/tsYID4CGRiWxzsgawzxG_g#Combined-Proposal-1-Selected),
deprecate `Camera2dBundle` and `Camera3dBundle` in favor of `Camera2d`
and `Camera3d`.

Adding a `Camera` without `Camera2d` or `Camera3d` now logs a warning,
as suggested by Cart [on
Discord](https://discord.com/channels/691052431525675048/1264881140007702558/1291506402832945273).
I would personally like cameras to work a bit differently and be split
into a few more components, to avoid some footguns and confusing
semantics, but that is more controversial, and shouldn't block this core
migration.

## Testing

I ran a few 2D and 3D examples, and tried cameras with and without
render graphs.

---

## Migration Guide

`Camera2dBundle` and `Camera3dBundle` have been deprecated in favor of
`Camera2d` and `Camera3d`. Inserting them will now also insert the other
components required by them automatically.
2024-10-05 01:59:52 +00:00
Joona Aalto
54006b107b
Migrate meshes and materials to required components (#15524)
# Objective

A big step in the migration to required components: meshes and
materials!

## Solution

As per the [selected
proposal](https://hackmd.io/@bevy/required_components/%2Fj9-PnF-2QKK0on1KQ29UWQ):

- Deprecate `MaterialMesh2dBundle`, `MaterialMeshBundle`, and
`PbrBundle`.
- Add `Mesh2d` and `Mesh3d` components, which wrap a `Handle<Mesh>`.
- Add `MeshMaterial2d<M: Material2d>` and `MeshMaterial3d<M: Material>`,
which wrap a `Handle<M>`.
- Meshes *without* a mesh material should be rendered with a default
material. The existence of a material is determined by
`HasMaterial2d`/`HasMaterial3d`, which is required by
`MeshMaterial2d`/`MeshMaterial3d`. This gets around problems with the
generics.

Previously:

```rust
commands.spawn(MaterialMesh2dBundle {
    mesh: meshes.add(Circle::new(100.0)).into(),
    material: materials.add(Color::srgb(7.5, 0.0, 7.5)),
    transform: Transform::from_translation(Vec3::new(-200., 0., 0.)),
    ..default()
});
```

Now:

```rust
commands.spawn((
    Mesh2d(meshes.add(Circle::new(100.0))),
    MeshMaterial2d(materials.add(Color::srgb(7.5, 0.0, 7.5))),
    Transform::from_translation(Vec3::new(-200., 0., 0.)),
));
```

If the mesh material is missing, previously nothing was rendered. Now,
it renders a white default `ColorMaterial` in 2D and a
`StandardMaterial` in 3D (this can be overridden). Below, only every
other entity has a material:

![Näyttökuva 2024-09-29
181746](https://github.com/user-attachments/assets/5c8be029-d2fe-4b8c-ae89-17a72ff82c9a)

![Näyttökuva 2024-09-29
181918](https://github.com/user-attachments/assets/58adbc55-5a1e-4c7d-a2c7-ed456227b909)

Why white? This is still open for discussion, but I think white makes
sense for a *default* material, while *invalid* asset handles pointing
to nothing should have something like a pink material to indicate that
something is broken (I don't handle that in this PR yet). This is kind
of a mix of Godot and Unity: Godot just renders a white material for
non-existent materials, while Unity renders nothing when no materials
exist, but renders pink for invalid materials. I can also change the
default material to pink if that is preferable though.

## Testing

I ran some 2D and 3D examples to test if anything changed visually. I
have not tested all examples or features yet however. If anyone wants to
test more extensively, it would be appreciated!

## Implementation Notes

- The relationship between `bevy_render` and `bevy_pbr` is weird here.
`bevy_render` needs `Mesh3d` for its own systems, but `bevy_pbr` has all
of the material logic, and `bevy_render` doesn't depend on it. I feel
like the two crates should be refactored in some way, but I think that's
out of scope for this PR.
- I didn't migrate meshlets to required components yet. That can
probably be done in a follow-up, as this is already a huge PR.
- It is becoming increasingly clear to me that we really, *really* want
to disallow raw asset handles as components. They caused me a *ton* of
headache here already, and it took me a long time to find every place
that queried for them or inserted them directly on entities, since there
were no compiler errors for it. If we don't remove the `Component`
derive, I expect raw asset handles to be a *huge* footgun for users as
we transition to wrapper components, especially as handles as components
have been the norm so far. I personally consider this to be a blocker
for 0.15: we need to migrate to wrapper components for asset handles
everywhere, and remove the `Component` derive. Also see
https://github.com/bevyengine/bevy/issues/14124.

---

## Migration Guide

Asset handles for meshes and mesh materials must now be wrapped in the
`Mesh2d` and `MeshMaterial2d` or `Mesh3d` and `MeshMaterial3d`
components for 2D and 3D respectively. Raw handles as components no
longer render meshes.

Additionally, `MaterialMesh2dBundle`, `MaterialMeshBundle`, and
`PbrBundle` have been deprecated. Instead, use the mesh and material
components directly.

Previously:

```rust
commands.spawn(MaterialMesh2dBundle {
    mesh: meshes.add(Circle::new(100.0)).into(),
    material: materials.add(Color::srgb(7.5, 0.0, 7.5)),
    transform: Transform::from_translation(Vec3::new(-200., 0., 0.)),
    ..default()
});
```

Now:

```rust
commands.spawn((
    Mesh2d(meshes.add(Circle::new(100.0))),
    MeshMaterial2d(materials.add(Color::srgb(7.5, 0.0, 7.5))),
    Transform::from_translation(Vec3::new(-200., 0., 0.)),
));
```

If the mesh material is missing, a white default material is now used.
Previously, nothing was rendered if the material was missing.

The `WithMesh2d` and `WithMesh3d` query filter type aliases have also
been removed. Simply use `With<Mesh2d>` or `With<Mesh3d>`.

---------

Co-authored-by: Tim Blackbird <justthecooldude@gmail.com>
Co-authored-by: Carter Anderson <mcanders1@gmail.com>
2024-10-01 21:33:17 +00:00
Benjamin Brienen
29508f065f
Fix floating point math (#15239)
# Objective

- Fixes #15236

## Solution

- Use bevy_math::ops instead of std floating point operations.

## Testing

- Did you test these changes? If so, how?
Unit tests and `cargo run -p ci -- test`

- How can other people (reviewers) test your changes? Is there anything
specific they need to know?
Execute `cargo run -p ci -- test` on Windows.

- If relevant, what platforms did you test these changes on, and are
there any important ones you can't test?
Windows

## Migration Guide

- Not a breaking change
- Projects should use bevy math where applicable

---------

Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: IQuick 143 <IQuick143cz@gmail.com>
Co-authored-by: Joona Aalto <jondolf.dev@gmail.com>
2024-09-16 23:28:12 +00:00
Christian Hughes
e939d6c33f
Remove remnant EntityHash and related types from bevy_utils (#15039)
# Objective

`EntityHash` and related types were moved from `bevy_utils` to
`bevy_ecs` in #11498, but seemed to have been accidentally reintroduced
a week later in #11707.

## Solution

Remove the old leftover code.

---

## Migration Guide

- Uses of `bevy::utils::{EntityHash, EntityHasher, EntityHashMap,
EntityHashSet}` now have to be imported from `bevy::ecs::entity`.
2024-09-09 15:24:17 +00:00
Allen Pocket
d93b78a66e
Remove unnecessary muts in RenderSet::QueueMeshes (#14953)
# Objective

Fixes #14952
2024-08-28 11:38:38 +00:00
charlotte
99ab0285e4
Fix mesh2_manual exapmle. (#14831)
Fix `mesh2d_manual` example from changes in #13069.

```
wgpu error: Validation Error

Caused by:
  In RenderPass::end
    In a set_pipeline command
      Render pipeline targets are incompatible with render pass
        Incompatible depth-stencil attachment format: the RenderPass uses a texture with format Some(Depth32Float) but the RenderPipeline with 'colored_mesh2d_pipeline' label uses an attachment with format None
```
2024-08-20 00:51:15 +00:00
charlotte
03fd1b46ef
Move Msaa to component (#14273)
Switches `Msaa` from being a globally configured resource to a per
camera view component.

Closes #7194

# Objective

Allow individual views to describe their own MSAA settings. For example,
when rendering to different windows or to different parts of the same
view.

## Solution

Make `Msaa` a component that is required on all camera bundles.

## Testing

Ran a variety of examples to ensure that nothing broke.

TODO:
- [ ] Make sure android still works per previous comment in
`extract_windows`.

---

## Migration Guide

`Msaa` is no longer configured as a global resource, and should be
specified on each spawned camera if a non-default setting is desired.

---------

Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: François Mockers <francois.mockers@vleue.com>
2024-07-22 18:28:23 +00:00
Patrick Walton
bc34216929
Pack multiple vertex and index arrays together into growable buffers. (#14257)
This commit uses the [`offset-allocator`] crate to combine vertex and
index arrays from different meshes into single buffers. Since the
primary source of `wgpu` overhead is from validation and synchronization
when switching buffers, this significantly improves Bevy's rendering
performance on many scenes.

This patch is a more flexible version of #13218, which also used slabs.
Unlike #13218, which used slabs of a fixed size, this commit implements
slabs that start small and can grow. In addition to reducing memory
usage, supporting slab growth reduces the number of vertex and index
buffer switches that need to happen during rendering, leading to
improved performance. To prevent pathological fragmentation behavior,
slabs are capped to a maximum size, and mesh arrays that are too large
get their own dedicated slabs.

As an additional improvement over #13218, this commit allows the
application to customize all allocator heuristics. The
`MeshAllocatorSettings` resource contains values that adjust the minimum
and maximum slab sizes, the cutoff point at which meshes get their own
dedicated slabs, and the rate at which slabs grow. Hopefully-sensible
defaults have been chosen for each value.

Unfortunately, WebGL 2 doesn't support the *base vertex* feature, which
is necessary to pack vertex arrays from different meshes into the same
buffer. `wgpu` represents this restriction as the downlevel flag
`BASE_VERTEX`. This patch detects that bit and ensures that all vertex
buffers get dedicated slabs on that platform. Even on WebGL 2, though,
we can combine all *index* arrays into single buffers to reduce buffer
changes, and we do so.

The following measurements are on Bistro:

Overall frame time improves from 8.74 ms to 5.53 ms (1.58x speedup):
![Screenshot 2024-07-09
163521](https://github.com/bevyengine/bevy/assets/157897/5d83c824-c0ee-434c-bbaf-218ff7212c48)

Render system time improves from 6.57 ms to 3.54 ms (1.86x speedup):
![Screenshot 2024-07-09
163559](https://github.com/bevyengine/bevy/assets/157897/d94e2273-c3a0-496a-9f88-20d394129610)

Opaque pass time improves from 4.64 ms to 2.33 ms (1.99x speedup):
![Screenshot 2024-07-09
163536](https://github.com/bevyengine/bevy/assets/157897/e4ef6e48-d60e-44ae-9a71-b9a731c99d9a)

## Migration Guide

### Changed

* Vertex and index buffers for meshes may now be packed alongside other
buffers, for performance.
* `GpuMesh` has been renamed to `RenderMesh`, to reflect the fact that
it no longer directly stores handles to GPU objects.
* Because meshes no longer have their own vertex and index buffers, the
responsibility for the buffers has moved from `GpuMesh` (now called
`RenderMesh`) to the `MeshAllocator` resource. To access the vertex data
for a mesh, use `MeshAllocator::mesh_vertex_slice`. To access the index
data for a mesh, use `MeshAllocator::mesh_index_slice`.

[`offset-allocator`]: https://github.com/pcwalton/offset-allocator
2024-07-16 20:33:15 +00:00
Ricky Taylor
9b9d3d81cb
Normalise matrix naming (#13489)
# Objective
- Fixes #10909
- Fixes #8492

## Solution
- Name all matrices `x_from_y`, for example `world_from_view`.

## Testing
- I've tested most of the 3D examples. The `lighting` example
particularly should hit a lot of the changes and appears to run fine.

---

## Changelog
- Renamed matrices across the engine to follow a `y_from_x` naming,
making the space conversion more obvious.

## Migration Guide
- `Frustum`'s `from_view_projection`, `from_view_projection_custom_far`
and `from_view_projection_no_far` were renamed to
`from_clip_from_world`, `from_clip_from_world_custom_far` and
`from_clip_from_world_no_far`.
- `ComputedCameraValues::projection_matrix` was renamed to
`clip_from_view`.
- `CameraProjection::get_projection_matrix` was renamed to
`get_clip_from_view` (this affects implementations on `Projection`,
`PerspectiveProjection` and `OrthographicProjection`).
- `ViewRangefinder3d::from_view_matrix` was renamed to
`from_world_from_view`.
- `PreviousViewData`'s members were renamed to `view_from_world` and
`clip_from_world`.
- `ExtractedView`'s `projection`, `transform` and `view_projection` were
renamed to `clip_from_view`, `world_from_view` and `clip_from_world`.
- `ViewUniform`'s `view_proj`, `unjittered_view_proj`,
`inverse_view_proj`, `view`, `inverse_view`, `projection` and
`inverse_projection` were renamed to `clip_from_world`,
`unjittered_clip_from_world`, `world_from_clip`, `world_from_view`,
`view_from_world`, `clip_from_view` and `view_from_clip`.
- `GpuDirectionalCascade::view_projection` was renamed to
`clip_from_world`.
- `MeshTransforms`' `transform` and `previous_transform` were renamed to
`world_from_local` and `previous_world_from_local`.
- `MeshUniform`'s `transform`, `previous_transform`,
`inverse_transpose_model_a` and `inverse_transpose_model_b` were renamed
to `world_from_local`, `previous_world_from_local`,
`local_from_world_transpose_a` and `local_from_world_transpose_b` (the
`Mesh` type in WGSL mirrors this, however `transform` and
`previous_transform` were named `model` and `previous_model`).
- `Mesh2dTransforms::transform` was renamed to `world_from_local`.
- `Mesh2dUniform`'s `transform`, `inverse_transpose_model_a` and
`inverse_transpose_model_b` were renamed to `world_from_local`,
`local_from_world_transpose_a` and `local_from_world_transpose_b` (the
`Mesh2d` type in WGSL mirrors this).
- In WGSL, in `bevy_pbr::mesh_functions`, `get_model_matrix` and
`get_previous_model_matrix` were renamed to `get_world_from_local` and
`get_previous_world_from_local`.
- In WGSL, `bevy_sprite::mesh2d_functions::get_model_matrix` was renamed
to `get_world_from_local`.
2024-06-03 16:56:53 +00:00
Patrick Walton
9da0b2a0ec
Make render phases render world resources instead of components. (#13277)
This commit makes us stop using the render world ECS for
`BinnedRenderPhase` and `SortedRenderPhase` and instead use resources
with `EntityHashMap`s inside. There are three reasons to do this:

1. We can use `clear()` to clear out the render phase collections
instead of recreating the components from scratch, allowing us to reuse
allocations.

2. This is a prerequisite for retained bins, because components can't be
retained from frame to frame in the render world, but resources can.

3. We want to move away from storing anything in components in the
render world ECS, and this is a step in that direction.

This patch results in a small performance benefit, due to point (1)
above.

## Changelog

### Changed

* The `BinnedRenderPhase` and `SortedRenderPhase` render world
components have been replaced with `ViewBinnedRenderPhases` and
`ViewSortedRenderPhases` resources.

## Migration Guide

* The `BinnedRenderPhase` and `SortedRenderPhase` render world
components have been replaced with `ViewBinnedRenderPhases` and
`ViewSortedRenderPhases` resources. Instead of querying for the
components, look the camera entity up in the
`ViewBinnedRenderPhases`/`ViewSortedRenderPhases` tables.
2024-05-21 18:23:04 +00:00
Patrick Walton
16531fb3e3
Implement GPU frustum culling. (#12889)
This commit implements opt-in GPU frustum culling, built on top of the
infrastructure in https://github.com/bevyengine/bevy/pull/12773. To
enable it on a camera, add the `GpuCulling` component to it. To
additionally disable CPU frustum culling, add the `NoCpuCulling`
component. Note that adding `GpuCulling` without `NoCpuCulling`
*currently* does nothing useful. The reason why `GpuCulling` doesn't
automatically imply `NoCpuCulling` is that I intend to follow this patch
up with GPU two-phase occlusion culling, and CPU frustum culling plus
GPU occlusion culling seems like a very commonly-desired mode.

Adding the `GpuCulling` component to a view puts that view into
*indirect mode*. This mode makes all drawcalls indirect, relying on the
mesh preprocessing shader to allocate instances dynamically. In indirect
mode, the `PreprocessWorkItem` `output_index` points not to a
`MeshUniform` instance slot but instead to a set of `wgpu`
`IndirectParameters`, from which it allocates an instance slot
dynamically if frustum culling succeeds. Batch building has been updated
to allocate and track indirect parameter slots, and the AABBs are now
supplied to the GPU as `MeshCullingData`.

A small amount of code relating to the frustum culling has been borrowed
from meshlets and moved into `maths.wgsl`. Note that standard Bevy
frustum culling uses AABBs, while meshlets use bounding spheres; this
means that not as much code can be shared as one might think.

This patch doesn't provide any way to perform GPU culling on shadow
maps, to avoid making this patch bigger than it already is. That can be
a followup.

## Changelog

### Added

* Frustum culling can now optionally be done on the GPU. To enable it,
add the `GpuCulling` component to a camera.
* To disable CPU frustum culling, add `NoCpuCulling` to a camera. Note
that `GpuCulling` doesn't automatically imply `NoCpuCulling`.
2024-04-28 12:50:00 +00:00
Rob Parrett
a1adba19a9
Fix custom pipeline in mesh2d_manual rendering other meshes (#11477)
# Objective

Fixes #11476

## Solution

Give the pipeline its own "mesh2d instances hashmap."

Pretty sure this is a good fix, but I am not super familiar with this
code so a rendering expert should take a look.

> your fix in the pull request works brilliantly for me too.
> -- _Discord user who pointed out bug_
2024-04-25 17:19:18 +00:00
JMS55
17633c1f75
Remove unused push constants (#13076)
The shader code was removed in #11280, but we never cleaned up the rust
code.
2024-04-23 21:43:46 +00:00
Patrick Walton
5caf085dac
Divide the single VisibleEntities list into separate lists for 2D meshes, 3D meshes, lights, and UI elements, for performance. (#12582)
This commit splits `VisibleEntities::entities` into four separate lists:
one for lights, one for 2D meshes, one for 3D meshes, and one for UI
elements. This allows `queue_material_meshes` and similar methods to
avoid examining entities that are obviously irrelevant. In particular,
this separation helps scenes with many skinned meshes, as the individual
bones are considered visible entities but have no rendered appearance.

Internally, `VisibleEntities::entities` is a `HashMap` from the `TypeId`
representing a `QueryFilter` to the appropriate `Entity` list. I had to
do this because `VisibleEntities` is located within an upstream crate
from the crates that provide lights (`bevy_pbr`) and 2D meshes
(`bevy_sprite`). As an added benefit, this setup allows apps to provide
their own types of renderable components, by simply adding a specialized
`check_visibility` to the schedule.

This provides a 16.23% end-to-end speedup on `many_foxes` with 10,000
foxes (24.06 ms/frame to 20.70 ms/frame).

## Migration guide

* `check_visibility` and `VisibleEntities` now store the four types of
renderable entities--2D meshes, 3D meshes, lights, and UI
elements--separately. If your custom rendering code examines
`VisibleEntities`, it will now need to specify which type of entity it's
interested in using the `WithMesh2d`, `WithMesh`, `WithLight`, and
`WithNode` types respectively. If your app introduces a new type of
renderable entity, you'll need to add an explicit call to
`check_visibility` to the schedule to accommodate your new component or
components.

## Analysis

`many_foxes`, 10,000 foxes: `main`:
![Screenshot 2024-03-31
114444](https://github.com/bevyengine/bevy/assets/157897/16ecb2ff-6e04-46c0-a4b0-b2fde2084bad)

`many_foxes`, 10,000 foxes, this branch:
![Screenshot 2024-03-31
114256](https://github.com/bevyengine/bevy/assets/157897/94dedae4-bd00-45b2-9aaf-dfc237004ddb)

`queue_material_meshes` (yellow = this branch, red = `main`):
![Screenshot 2024-03-31
114637](https://github.com/bevyengine/bevy/assets/157897/f90912bd-45bd-42c4-bd74-57d98a0f036e)

`queue_shadows` (yellow = this branch, red = `main`):
![Screenshot 2024-03-31
114607](https://github.com/bevyengine/bevy/assets/157897/6ce693e3-20c0-4234-8ec9-a6f191299e2d)
2024-04-11 20:33:20 +00:00
Robert Swain
ab7cbfa8fc
Consolidate Render(Ui)Materials(2d) into RenderAssets (#12827)
# Objective

- Replace `RenderMaterials` / `RenderMaterials2d` / `RenderUiMaterials`
with `RenderAssets` to enable implementing changes to one thing,
`RenderAssets`, that applies to all use cases rather than duplicating
changes everywhere for multiple things that should be one thing.
- Adopts #8149 

## Solution

- Make RenderAsset generic over the destination type rather than the
source type as in #8149
- Use `RenderAssets<PreparedMaterial<M>>` etc for render materials

---

## Changelog

- Changed:
- The `RenderAsset` trait is now implemented on the destination type.
Its `SourceAsset` associated type refers to the type of the source
asset.
- `RenderMaterials`, `RenderMaterials2d`, and `RenderUiMaterials` have
been replaced by `RenderAssets<PreparedMaterial<M>>` and similar.

## Migration Guide

- `RenderAsset` is now implemented for the destination type rather that
the source asset type. The source asset type is now the `RenderAsset`
trait's `SourceAsset` associated type.
2024-04-09 13:26:34 +00:00
Patrick Walton
37522fd0ae
Micro-optimize queue_material_meshes, primarily to remove bit manipulation. (#12791)
This commit makes the following optimizations:

## `MeshPipelineKey`/`BaseMeshPipelineKey` split

`MeshPipelineKey` has been split into `BaseMeshPipelineKey`, which lives
in `bevy_render` and `MeshPipelineKey`, which lives in `bevy_pbr`.
Conceptually, `BaseMeshPipelineKey` is a superclass of
`MeshPipelineKey`. For `BaseMeshPipelineKey`, the bits start at the
highest (most significant) bit and grow downward toward the lowest bit;
for `MeshPipelineKey`, the bits start at the lowest bit and grow upward
toward the highest bit. This prevents them from colliding.

The goal of this is to avoid having to reassemble bits of the pipeline
key for every mesh every frame. Instead, we can just use a bitwise or
operation to combine the pieces that make up a `MeshPipelineKey`.

## `specialize_slow`

Previously, all of `specialize()` was marked as `#[inline]`. This
bloated `queue_material_meshes` unnecessarily, as a large chunk of it
ended up being a slow path that was rarely hit. This commit refactors
the function to move the slow path to `specialize_slow()`.

Together, these two changes shave about 5% off `queue_material_meshes`:

![Screenshot 2024-03-29
130002](https://github.com/bevyengine/bevy/assets/157897/a7e5a994-a807-4328-b314-9003429dcdd2)

## Migration Guide

- The `primitive_topology` field on `GpuMesh` is now an accessor method:
`GpuMesh::primitive_topology()`.
- For performance reasons, `MeshPipelineKey` has been split into
`BaseMeshPipelineKey`, which lives in `bevy_render`, and
`MeshPipelineKey`, which lives in `bevy_pbr`. These two should be
combined with bitwise-or to produce the final `MeshPipelineKey`.
2024-04-01 21:58:53 +00:00
Cameron
01649f13e2
Refactor App and SubApp internals for better separation (#9202)
# Objective

This is a necessary precursor to #9122 (this was split from that PR to
reduce the amount of code to review all at once).

Moving `!Send` resource ownership to `App` will make it unambiguously
`!Send`. `SubApp` must be `Send`, so it can't wrap `App`.

## Solution

Refactor `App` and `SubApp` to not have a recursive relationship. Since
`SubApp` no longer wraps `App`, once `!Send` resources are moved out of
`World` and into `App`, `SubApp` will become unambiguously `Send`.

There could be less code duplication between `App` and `SubApp`, but
that would break `App` method chaining.

## Changelog

- `SubApp` no longer wraps `App`.
- `App` fields are no longer publicly accessible.
- `App` can no longer be converted into a `SubApp`.
- Various methods now return references to a `SubApp` instead of an
`App`.
## Migration Guide

- To construct a sub-app, use `SubApp::new()`. `App` can no longer
convert into `SubApp`.
- If you implemented a trait for `App`, you may want to implement it for
`SubApp` as well.
- If you're accessing `app.world` directly, you now have to use
`app.world()` and `app.world_mut()`.
- `App::sub_app` now returns `&SubApp`.
- `App::sub_app_mut`  now returns `&mut SubApp`.
- `App::get_sub_app` now returns `Option<&SubApp>.`
- `App::get_sub_app_mut` now returns `Option<&mut SubApp>.`
2024-03-31 03:16:10 +00:00
Patrick Walton
4dadebd9c4
Improve performance by binning together opaque items instead of sorting them. (#12453)
Today, we sort all entities added to all phases, even the phases that
don't strictly need sorting, such as the opaque and shadow phases. This
results in a performance loss because our `PhaseItem`s are rather large
in memory, so sorting is slow. Additionally, determining the boundaries
of batches is an O(n) process.

This commit makes Bevy instead applicable place phase items into *bins*
keyed by *bin keys*, which have the invariant that everything in the
same bin is potentially batchable. This makes determining batch
boundaries O(1), because everything in the same bin can be batched.
Instead of sorting each entity, we now sort only the bin keys. This
drops the sorting time to near-zero on workloads with few bins like
`many_cubes --no-frustum-culling`. Memory usage is improved too, with
batch boundaries and dynamic indices now implicit instead of explicit.
The improved memory usage results in a significant win even on
unbatchable workloads like `many_cubes --no-frustum-culling
--vary-material-data-per-instance`, presumably due to cache effects.

Not all phases can be binned; some, such as transparent and transmissive
phases, must still be sorted. To handle this, this commit splits
`PhaseItem` into `BinnedPhaseItem` and `SortedPhaseItem`. Most of the
logic that today deals with `PhaseItem`s has been moved to
`SortedPhaseItem`. `BinnedPhaseItem` has the new logic.

Frame time results (in ms/frame) are as follows:

| Benchmark                | `binning` | `main`  | Speedup |
| ------------------------ | --------- | ------- | ------- |
| `many_cubes -nfc -vpi` | 232.179     | 312.123   | 34.43%  |
| `many_cubes -nfc`        | 25.874 | 30.117 | 16.40%  |
| `many_foxes`             | 3.276 | 3.515 | 7.30%   |

(`-nfc` is short for `--no-frustum-culling`; `-vpi` is short for
`--vary-per-instance`.)

---

## Changelog

### Changed

* Render phases have been split into binned and sorted phases. Binned
phases, such as the common opaque phase, achieve improved CPU
performance by avoiding the sorting step.

## Migration Guide

- `PhaseItem` has been split into `BinnedPhaseItem` and
`SortedPhaseItem`. If your code has custom `PhaseItem`s, you will need
to migrate them to one of these two types. `SortedPhaseItem` requires
the fewest code changes, but you may want to pick `BinnedPhaseItem` if
your phase doesn't require sorting, as that enables higher performance.

## Tracy graphs

`many-cubes --no-frustum-culling`, `main` branch:
<img width="1064" alt="Screenshot 2024-03-12 180037"
src="https://github.com/bevyengine/bevy/assets/157897/e1180ce8-8e89-46d2-85e3-f59f72109a55">

`many-cubes --no-frustum-culling`, this branch:
<img width="1064" alt="Screenshot 2024-03-12 180011"
src="https://github.com/bevyengine/bevy/assets/157897/0899f036-6075-44c5-a972-44d95895f46c">

You can see that `batch_and_prepare_binned_render_phase` is a much
smaller fraction of the time. Zooming in on that function, with yellow
being this branch and red being `main`, we see:

<img width="1064" alt="Screenshot 2024-03-12 175832"
src="https://github.com/bevyengine/bevy/assets/157897/0dfc8d3f-49f4-496e-8825-a66e64d356d0">

The binning happens in `queue_material_meshes`. Again with yellow being
this branch and red being `main`:
<img width="1064" alt="Screenshot 2024-03-12 175755"
src="https://github.com/bevyengine/bevy/assets/157897/b9b20dc1-11c8-400c-a6cc-1c2e09c1bb96">

We can see that there is a small regression in `queue_material_meshes`
performance, but it's not nearly enough to outweigh the large gains in
`batch_and_prepare_binned_render_phase`.

---------

Co-authored-by: James Liu <contact@jamessliu.com>
2024-03-30 02:55:02 +00:00
François Mockers
ece6249830
fix example mesh2d_manual in wasm/webgl2 (#12753)
# Objective

- Example `mesh2d_manual` crashes in wasm/webgl2, as reported in
https://github.com/bevyengine/bevy-website/issues/1123#issuecomment-2019479670
```
wgpu error: Validation Error

Caused by:
    In a RenderPass
      note: encoder = `<CommandBuffer-(0, 1, Gl)>`
    In a set_push_constant command
    Provided push constant is for stage(s) ShaderStages(VERTEX), however the pipeline layout has no push constant range for the stage(s) ShaderStages(VERTEX)
```

## Solution

- Properly declare the push constant as in
4508077297/crates/bevy_sprite/src/mesh2d/mesh.rs (L514-L524)
2024-03-28 15:53:42 +00:00
Jacques Schutte
4508077297
Move FloatOrd into bevy_math (#12732)
# Objective

- Fixes #12712

## Solution

- Move the `float_ord.rs` file to `bevy_math`
- Change any `bevy_utils::FloatOrd` statements to `bevy_math::FloatOrd`

---

## Changelog

- Moved `FloatOrd` from `bevy_utils` to `bevy_math`

## Migration Guide

- References to `bevy_utils::FloatOrd` should be changed to
`bevy_math::FloatOrd`
2024-03-27 18:30:11 +00:00
Vitaliy Sapronenko
67cc605e9f
Removed Into<AssedId<T>> for Handle<T> as mentioned in #12600 (#12655)
Fixes #12600 

## Solution

Removed Into<AssetId<T>> for Handle<T> as proposed in Issue
conversation, fixed dependent code

## Migration guide

If you use passing Handle by value as AssetId, you should pass reference
or call .id() method on it
Before (0.13):
`assets.insert(handle, value);`
After (0.14):
`assets.insert(&handle, value);`
or
`assets.insert(handle.id(), value);`
2024-03-22 20:26:12 +00:00
Alice Cecile
599e5e4e76
Migrate from LegacyColor to bevy_color::Color (#12163)
# Objective

- As part of the migration process we need to a) see the end effect of
the migration on user ergonomics b) check for serious perf regressions
c) actually migrate the code
- To accomplish this, I'm going to attempt to migrate all of the
remaining user-facing usages of `LegacyColor` in one PR, being careful
to keep a clean commit history.
- Fixes #12056.

## Solution

I've chosen to use the polymorphic `Color` type as our standard
user-facing API.

- [x] Migrate `bevy_gizmos`.
- [x] Take `impl Into<Color>` in all `bevy_gizmos` APIs
- [x] Migrate sprites
- [x] Migrate UI
- [x] Migrate `ColorMaterial`
- [x] Migrate `MaterialMesh2D`
- [x] Migrate fog
- [x] Migrate lights
- [x] Migrate StandardMaterial
- [x] Migrate wireframes
- [x] Migrate clear color
- [x] Migrate text
- [x] Migrate gltf loader
- [x] Register color types for reflection
- [x] Remove `LegacyColor`
- [x] Make sure CI passes

Incidental improvements to ease migration:

- added `Color::srgba_u8`, `Color::srgba_from_array` and friends
- added `set_alpha`, `is_fully_transparent` and `is_fully_opaque` to the
`Alpha` trait
- add and immediately deprecate (lol) `Color::rgb` and friends in favor
of more explicit and consistent `Color::srgb`
- standardized on white and black for most example text colors
- added vector field traits to `LinearRgba`: ~~`Add`, `Sub`,
`AddAssign`, `SubAssign`,~~ `Mul<f32>` and `Div<f32>`. Multiplications
and divisions do not scale alpha. `Add` and `Sub` have been cut from
this PR.
- added `LinearRgba` and `Srgba` `RED/GREEN/BLUE`
- added `LinearRgba_to_f32_array` and `LinearRgba::to_u32`

## Migration Guide

Bevy's color types have changed! Wherever you used a
`bevy::render::Color`, a `bevy::color::Color` is used instead.

These are quite similar! Both are enums storing a color in a specific
color space (or to be more precise, using a specific color model).
However, each of the different color models now has its own type.

TODO...

- `Color::rgba`, `Color::rgb`, `Color::rbga_u8`, `Color::rgb_u8`,
`Color::rgb_from_array` are now `Color::srgba`, `Color::srgb`,
`Color::srgba_u8`, `Color::srgb_u8` and `Color::srgb_from_array`.
- `Color::set_a` and `Color::a` is now `Color::set_alpha` and
`Color::alpha`. These are part of the `Alpha` trait in `bevy_color`.
- `Color::is_fully_transparent` is now part of the `Alpha` trait in
`bevy_color`
- `Color::r`, `Color::set_r`, `Color::with_r` and the equivalents for
`g`, `b` `h`, `s` and `l` have been removed due to causing silent
relatively expensive conversions. Convert your `Color` into the desired
color space, perform your operations there, and then convert it back
into a polymorphic `Color` enum.
- `Color::hex` is now `Srgba::hex`. Call `.into` or construct a
`Color::Srgba` variant manually to convert it.
- `WireframeMaterial`, `ExtractedUiNode`, `ExtractedDirectionalLight`,
`ExtractedPointLight`, `ExtractedSpotLight` and `ExtractedSprite` now
store a `LinearRgba`, rather than a polymorphic `Color`
- `Color::rgb_linear` and `Color::rgba_linear` are now
`Color::linear_rgb` and `Color::linear_rgba`
- The various CSS color constants are no longer stored directly on
`Color`. Instead, they're defined in the `Srgba` color space, and
accessed via `bevy::color::palettes::css`. Call `.into()` on them to
convert them into a `Color` for quick debugging use, and consider using
the much prettier `tailwind` palette for prototyping.
- The `LIME_GREEN` color has been renamed to `LIMEGREEN` to comply with
the standard naming.
- Vector field arithmetic operations on `Color` (add, subtract, multiply
and divide by a f32) have been removed. Instead, convert your colors
into `LinearRgba` space, and perform your operations explicitly there.
This is particularly relevant when working with emissive or HDR colors,
whose color channel values are routinely outside of the ordinary 0 to 1
range.
- `Color::as_linear_rgba_f32` has been removed. Call
`LinearRgba::to_f32_array` instead, converting if needed.
- `Color::as_linear_rgba_u32` has been removed. Call
`LinearRgba::to_u32` instead, converting if needed.
- Several other color conversion methods to transform LCH or HSL colors
into float arrays or `Vec` types have been removed. Please reimplement
these externally or open a PR to re-add them if you found them
particularly useful.
- Various methods on `Color` such as `rgb` or `hsl` to convert the color
into a specific color space have been removed. Convert into
`LinearRgba`, then to the color space of your choice.
- Various implicitly-converting color value methods on `Color` such as
`r`, `g`, `b` or `h` have been removed. Please convert it into the color
space of your choice, then check these properties.
- `Color` no longer implements `AsBindGroup`. Store a `LinearRgba`
internally instead to avoid conversion costs.

---------

Co-authored-by: Alice Cecile <alice.i.cecil@gmail.com>
Co-authored-by: Afonso Lage <lage.afonso@gmail.com>
Co-authored-by: Rob Parrett <robparrett@gmail.com>
Co-authored-by: Zachary Harrold <zac@harrold.com.au>
2024-02-29 19:35:12 +00:00
Alice Cecile
de004da8d5
Rename bevy_render::Color to LegacyColor (#12069)
# Objective

The migration process for `bevy_color` (#12013) will be fairly involved:
there will be hundreds of affected files, and a large number of APIs.

## Solution

To allow us to proceed granularly, we're going to keep both
`bevy_color::Color` (new) and `bevy_render::Color` (old) around until
the migration is complete.

However, simply doing this directly is confusing! They're both called
`Color`, making it very hard to tell when a portion of the code has been
ported.

As discussed in #12056, by renaming the old `Color` type, we can make it
easier to gradually migrate over, one API at a time.

## Migration Guide

THIS MIGRATION GUIDE INTENTIONALLY LEFT BLANK.

This change should not be shipped to end users: delete this section in
the final migration guide!

---------

Co-authored-by: Alice Cecile <alice.i.cecil@gmail.com>
2024-02-24 21:35:32 +00:00
Lynn
4c86ad6aed
Mesh insert indices (#11745)
# Objective

- Fixes #11740 

## Solution

- Turned `Mesh::set_indices` into `Mesh::insert_indices` and added
related methods for completeness.

---

## Changelog

- Replaced `Mesh::set_indices(indices: Option<Indices>)` with
`Mesh::insert_indices(indices: Indices)`
- Replaced `Mesh::with_indices(indices: Option<Indices>)` with
`Mesh::with_inserted_indices(indices: Indices)` and
`Mesh::with_removed_indices()` mirroring the API for inserting /
removing attributes.
- Updated the examples and internal uses of the APIs described above.

## Migration Guide

- Use `Mesh::insert_indices` or `Mesh::with_inserted_indices` instead of
`Mesh::set_indices` / `Mesh::with_indices`.
- If you have passed `None` to `Mesh::set_indices` or
`Mesh::with_indices` you should use `Mesh::remove_indices` or
`Mesh::with_removed_indices` instead.

---------

Co-authored-by: François <mockersf@gmail.com>
2024-02-06 23:31:48 +00:00
Brian Reavis
6b40b6749e
RenderAssetPersistencePolicy → RenderAssetUsages (#11399)
# Objective

Right now, all assets in the main world get extracted and prepared in
the render world (if the asset's using the RenderAssetPlugin). This is
unfortunate for two cases:

1. **TextureAtlas** / **FontAtlas**: This one's huge. The individual
`Image` assets that make up the atlas are cloned and prepared
individually when there's no reason for them to be. The atlas textures
are built on the CPU in the main world. *There can be hundreds of images
that get prepared for rendering only not to be used.*
2. If one loads an Image and needs to transform it in a system before
rendering it, kind of like the [decompression
example](https://github.com/bevyengine/bevy/blob/main/examples/asset/asset_decompression.rs#L120),
there's a price paid for extracting & preparing the asset that's not
intended to be rendered yet.

------

* References #10520
* References #1782

## Solution

This changes the `RenderAssetPersistencePolicy` enum to bitflags. I felt
that the objective with the parameter is so similar in nature to wgpu's
[`TextureUsages`](https://docs.rs/wgpu/latest/wgpu/struct.TextureUsages.html)
and
[`BufferUsages`](https://docs.rs/wgpu/latest/wgpu/struct.BufferUsages.html),
that it may as well be just like that.

```rust
// This asset only needs to be in the main world. Don't extract and prepare it.
RenderAssetUsages::MAIN_WORLD

// Keep this asset in the main world and  
RenderAssetUsages::MAIN_WORLD | RenderAssetUsages::RENDER_WORLD

// This asset is only needed in the render world. Remove it from the asset server once extracted.
RenderAssetUsages::RENDER_WORLD
```

### Alternate Solution

I considered introducing a third field to `RenderAssetPersistencePolicy`
enum:
```rust
enum RenderAssetPersistencePolicy {
    /// Keep the asset in the main world after extracting to the render world.
    Keep,
    /// Remove the asset from the main world after extracting to the render world.
    Unload,
    /// This doesn't need to be in the render world at all.
    NoExtract, // <-----
}
```
Functional, but this seemed like shoehorning. Another option is renaming
the enum to something like:
```rust
enum RenderAssetExtractionPolicy {
    /// Extract the asset and keep it in the main world.
    Extract,
    /// Remove the asset from the main world after extracting to the render world.
    ExtractAndUnload,
    /// This doesn't need to be in the render world at all.
    NoExtract,
}
```
I think this last one could be a good option if the bitflags are too
clunky.

## Migration Guide

* `RenderAssetPersistencePolicy::Keep` → `RenderAssetUsage::MAIN_WORLD |
RenderAssetUsage::RENDER_WORLD` (or `RenderAssetUsage::default()`)
* `RenderAssetPersistencePolicy::Unload` →
`RenderAssetUsage::RENDER_WORLD`
* For types implementing the `RenderAsset` trait, change `fn
persistence_policy(&self) -> RenderAssetPersistencePolicy` to `fn
asset_usage(&self) -> RenderAssetUsages`.
* Change any references to `cpu_persistent_access`
(`RenderAssetPersistencePolicy`) to `asset_usage` (`RenderAssetUsage`).
This applies to `Image`, `Mesh`, and a few other types.
2024-01-30 13:22:10 +00:00
JMS55
44424391fe
Unload render assets from RAM (#10520)
# Objective
- No point in keeping Meshes/Images in RAM once they're going to be sent
to the GPU, and kept in VRAM. This saves a _significant_ amount of
memory (several GBs) on scenes like bistro.
- References
  - https://github.com/bevyengine/bevy/pull/1782
  - https://github.com/bevyengine/bevy/pull/8624 

## Solution
- Augment RenderAsset with the capability to unload the underlying asset
after extracting to the render world.
- Mesh/Image now have a cpu_persistent_access field. If this field is
RenderAssetPersistencePolicy::Unload, the asset will be unloaded from
Assets<T>.
- A new AssetEvent is sent upon dropping the last strong handle for the
asset, which signals to the RenderAsset to remove the GPU version of the
asset.

---

## Changelog
- Added `AssetEvent::NoLongerUsed` and
`AssetEvent::is_no_longer_used()`. This event is sent when the last
strong handle of an asset is dropped.
- Rewrote the API for `RenderAsset` to allow for unloading the asset
data from the CPU.
- Added `RenderAssetPersistencePolicy`.
- Added `Mesh::cpu_persistent_access` for memory savings when the asset
is not needed except for on the GPU.
- Added `Image::cpu_persistent_access` for memory savings when the asset
is not needed except for on the GPU.
- Added `ImageLoaderSettings::cpu_persistent_access`.
- Added `ExrTextureLoaderSettings`.
- Added `HdrTextureLoaderSettings`.

## Migration Guide
- Asset loaders (GLTF, etc) now load meshes and textures without
`cpu_persistent_access`. These assets will be removed from
`Assets<Mesh>` and `Assets<Image>` once `RenderAssets<Mesh>` and
`RenderAssets<Image>` contain the GPU versions of these assets, in order
to reduce memory usage. If you require access to the asset data from the
CPU in future frames after the GLTF asset has been loaded, modify all
dependent `Mesh` and `Image` assets and set `cpu_persistent_access` to
`RenderAssetPersistencePolicy::Keep`.
- `Mesh` now requires a new `cpu_persistent_access` field. Set it to
`RenderAssetPersistencePolicy::Keep` to mimic the previous behavior.
- `Image` now requires a new `cpu_persistent_access` field. Set it to
`RenderAssetPersistencePolicy::Keep` to mimic the previous behavior.
- `MorphTargetImage::new()` now requires a new `cpu_persistent_access`
parameter. Set it to `RenderAssetPersistencePolicy::Keep` to mimic the
previous behavior.
- `DynamicTextureAtlasBuilder::add_texture()` now requires that the
`TextureAtlas` you pass has an `Image` with `cpu_persistent_access:
RenderAssetPersistencePolicy::Keep`. Ensure you construct the image
properly for the texture atlas.
- The `RenderAsset` trait has significantly changed, and requires
adapting your existing implementations.
  - The trait now requires `Clone`.
- The `ExtractedAsset` associated type has been removed (the type itself
is now extracted).
  - The signature of `prepare_asset()` is slightly different
- A new `persistence_policy()` method is now required (return
RenderAssetPersistencePolicy::Unload to match the previous behavior).
- Match on the new `NoLongerUsed` variant for exhaustive matches of
`AssetEvent`.
2024-01-03 03:31:04 +00:00
JMS55
4bf20e7d27
Swap material and mesh bind groups (#10485)
# Objective
- Materials should be a more frequent rebind then meshes (due to being
able to use a single vertex buffer, such as in #10164) and therefore
should be in a higher bind group.

---

## Changelog
- For 2d and 3d mesh/material setups (but not UI materials, or other
rendering setups such as gizmos, sprites, or text), mesh data is now in
bind group 1, and material data is now in bind group 2, which is swapped
from how they were before.

## Migration Guide
- Custom 2d and 3d mesh/material shaders should now use bind group 2
`@group(2) @binding(x)` for their bound resources, instead of bind group
1.
- Many internal pieces of rendering code have changed so that mesh data
is now in bind group 1, and material data is now in bind group 2.
Semi-custom rendering setups (that don't use the Material or Material2d
APIs) should adapt to these changes.
2023-11-28 22:26:22 +00:00
Ame
951c9bb1a2
Add [lints] table, fix adding #![allow(clippy::type_complexity)] everywhere (#10011)
# Objective

- Fix adding `#![allow(clippy::type_complexity)]` everywhere. like #9796

## Solution

- Use the new [lints] table that will land in 1.74
(https://doc.rust-lang.org/nightly/cargo/reference/unstable.html#lints)
- inherit lint to the workspace, crates and examples.
```
[lints]
workspace = true
```

## Changelog

- Bump rust version to 1.74
- Enable lints table for the workspace
```toml
[workspace.lints.clippy]
type_complexity = "allow"
```
- Allow type complexity for all crates and examples
```toml
[lints]
workspace = true
```

---------

Co-authored-by: Martín Maita <47983254+mnmaita@users.noreply.github.com>
2023-11-18 20:58:48 +00:00
Guillaume Gomez
fe7e31ea76
Fix intra-doc link warnings (#10445)
When `cargo doc -Zunstable-options -Zrustdoc-scrape-examples` (trying to
figure out why it doesn't work with bevy), I had the following warnings:

```
warning: unresolved link to `Quad`
 --> examples/2d/mesh2d.rs:1:66
  |
1 | //! Shows how to render a polygonal [`Mesh`], generated from a [`Quad`] primitive, in a 2D scene.
  |                                                                  ^^^^ no item named `Quad` in scope
  |
  = help: to escape `[` and `]` characters, add '\' before them like `\[` or `\]`
  = note: `#[warn(rustdoc::broken_intra_doc_links)]` on by default

warning: `bevy` (example "mesh2d") generated 1 warning
warning: unresolved link to `update_weights`
 --> examples/animation/morph_targets.rs:6:17
  |
6 | //!   See the [`update_weights`] system for details.
  |                 ^^^^^^^^^^^^^^ no item named `update_weights` in scope
  |
  = help: to escape `[` and `]` characters, add '\' before them like `\[` or `\]`
  = note: `#[warn(rustdoc::broken_intra_doc_links)]` on by default

warning: public documentation for `morph_targets` links to private item `name_morphs`
 --> examples/animation/morph_targets.rs:7:43
  |
7 | //! - How to read morph target names in [`name_morphs`].
  |                                           ^^^^^^^^^^^ this item is private
  |
  = note: this link will resolve properly if you pass `--document-private-items`
  = note: `#[warn(rustdoc::private_intra_doc_links)]` on by default

warning: public documentation for `morph_targets` links to private item `setup_animations`
 --> examples/animation/morph_targets.rs:8:48
  |
8 | //! - How to play morph target animations in [`setup_animations`].
  |                                                ^^^^^^^^^^^^^^^^ this item is private
  |
  = note: this link will resolve properly if you pass `--document-private-items`

warning: `bevy` (example "morph_targets") generated 3 warnings
warning: unresolved link to `Quad`
 --> examples/2d/mesh2d_vertex_color_texture.rs:1:66
  |
1 | //! Shows how to render a polygonal [`Mesh`], generated from a [`Quad`] primitive, in a 2D scene.
  |                                                                  ^^^^ no item named `Quad` in scope
  |
  = help: to escape `[` and `]` characters, add '\' before them like `\[` or `\]`
  = note: `#[warn(rustdoc::broken_intra_doc_links)]` on by default

warning: `bevy` (example "mesh2d_vertex_color_texture") generated 1 warning
warning: unresolved link to `UIScale`
 --> examples/ui/ui_scaling.rs:1:36
  |
1 | //! This example illustrates the [`UIScale`] resource from `bevy_ui`.
  |                                    ^^^^^^^ no item named `UIScale` in scope
  |
  = help: to escape `[` and `]` characters, add '\' before them like `\[` or `\]`
  = note: `#[warn(rustdoc::broken_intra_doc_links)]` on by default

warning: `bevy` (example "ui_scaling") generated 1 warning
warning: unresolved link to `dependencies`
 --> examples/app/headless.rs:5:6
  |
5 | //! [dependencies]
  |      ^^^^^^^^^^^^ no item named `dependencies` in scope
  |
  = help: to escape `[` and `]` characters, add '\' before them like `\[` or `\]`
  = note: `#[warn(rustdoc::broken_intra_doc_links)]` on by default

warning: `bevy` (example "headless") generated 1 warning
warning: unresolved link to `Material2d`
 --> examples/2d/mesh2d_manual.rs:3:26
  |
3 | //! It doesn't use the [`Material2d`] abstraction, but changes the vertex buffer to include verte...
  |                          ^^^^^^^^^^ no item named `Material2d` in scope
  |
  = help: to escape `[` and `]` characters, add '\' before them like `\[` or `\]`
  = note: `#[warn(rustdoc::broken_intra_doc_links)]` on by default

warning: `bevy` (example "mesh2d_manual") generated 1 warning
```
2023-11-08 14:33:46 +00:00
robtfm
61bad4eb57
update shader imports (#10180)
# Objective

- bump naga_oil to 0.10
- update shader imports to use rusty syntax

## Migration Guide

naga_oil 0.10 reworks the import mechanism to support more syntax to
make it more rusty, and test for item use before importing to determine
which imports are modules and which are items, which allows:

- use rust-style imports
```
#import bevy_pbr::{
    pbr_functions::{alpha_discard as discard, apply_pbr_lighting}, 
    mesh_bindings,
}
```

- import partial paths:
```
#import part::of::path
...
path::remainder::function();
```
which will call to `part::of::path::remainder::function`

- use fully qualified paths without importing:
```
// #import bevy_pbr::pbr_functions
bevy_pbr::pbr_functions::pbr()
```
- use imported items without qualifying
```
#import bevy_pbr::pbr_functions::pbr
// for backwards compatibility the old style is still supported:
// #import bevy_pbr::pbr_functions pbr
...
pbr()
```

- allows most imported items to end with `_` and numbers (naga_oil#30).
still doesn't allow struct members to end with `_` or numbers but it's
progress.

- the vast majority of existing shader code will work without changes,
but will emit "deprecated" warnings for old-style imports. these can be
suppressed with the `allow-deprecated` feature.

- partly breaks overrides (as far as i'm aware nobody uses these yet) -
now overrides will only be applied if the overriding module is added as
an additional import in the arguments to `Composer::make_naga_module` or
`Composer::add_composable_module`. this is necessary to support
determining whether imports are modules or items.
2023-10-21 11:51:58 +00:00
François
154a490445
fix example mesh2d_manual (#9941)
# Objective

- After https://github.com/bevyengine/bevy/pull/9903, example
`mesh2d_manual` doesn't render anything

## Solution

- Fix the example using the new `RenderMesh2dInstances`
2023-10-06 20:13:09 +00:00
Robert Swain
5c884c5a15
Automatic batching/instancing of draw commands (#9685)
# Objective

- Implement the foundations of automatic batching/instancing of draw
commands as the next step from #89
- NOTE: More performance improvements will come when more data is
managed and bound in ways that do not require rebinding such as mesh,
material, and texture data.

## Solution

- The core idea for batching of draw commands is to check whether any of
the information that has to be passed when encoding a draw command
changes between two things that are being drawn according to the sorted
render phase order. These should be things like the pipeline, bind
groups and their dynamic offsets, index/vertex buffers, and so on.
  - The following assumptions have been made:
- Only entities with prepared assets (pipelines, materials, meshes) are
queued to phases
- View bindings are constant across a phase for a given draw function as
phases are per-view
- `batch_and_prepare_render_phase` is the only system that performs this
batching and has sole responsibility for preparing the per-object data.
As such the mesh binding and dynamic offsets are assumed to only vary as
a result of the `batch_and_prepare_render_phase` system, e.g. due to
having to split data across separate uniform bindings within the same
buffer due to the maximum uniform buffer binding size.
- Implement `GpuArrayBuffer` for `Mesh2dUniform` to store Mesh2dUniform
in arrays in GPU buffers rather than each one being at a dynamic offset
in a uniform buffer. This is the same optimisation that was made for 3D
not long ago.
- Change batch size for a range in `PhaseItem`, adding API for getting
or mutating the range. This is more flexible than a size as the length
of the range can be used in place of the size, but the start and end can
be otherwise whatever is needed.
- Add an optional mesh bind group dynamic offset to `PhaseItem`. This
avoids having to do a massive table move just to insert
`GpuArrayBufferIndex` components.

## Benchmarks

All tests have been run on an M1 Max on AC power. `bevymark` and
`many_cubes` were modified to use 1920x1080 with a scale factor of 1. I
run a script that runs a separate Tracy capture process, and then runs
the bevy example with `--features bevy_ci_testing,trace_tracy` and
`CI_TESTING_CONFIG=../benchmark.ron` with the contents of
`../benchmark.ron`:
```rust
(
    exit_after: Some(1500)
)
```
...in order to run each test for 1500 frames.

The recent changes to `many_cubes` and `bevymark` added reproducible
random number generation so that with the same settings, the same rng
will occur. They also added benchmark modes that use a fixed delta time
for animations. Combined this means that the same frames should be
rendered both on main and on the branch.

The graphs compare main (yellow) to this PR (red).

### 3D Mesh `many_cubes --benchmark`

<img width="1411" alt="Screenshot 2023-09-03 at 23 42 10"
src="https://github.com/bevyengine/bevy/assets/302146/2088716a-c918-486c-8129-090b26fd2bc4">
The mesh and material are the same for all instances. This is basically
the best case for the initial batching implementation as it results in 1
draw for the ~11.7k visible meshes. It gives a ~30% reduction in median
frame time.

The 1000th frame is identical using the flip tool:

![flip many_cubes-main-mesh3d many_cubes-batching-mesh3d 67ppd
ldr](https://github.com/bevyengine/bevy/assets/302146/2511f37a-6df8-481a-932f-706ca4de7643)

```
     Mean: 0.000000
     Weighted median: 0.000000
     1st weighted quartile: 0.000000
     3rd weighted quartile: 0.000000
     Min: 0.000000
     Max: 0.000000
     Evaluation time: 0.4615 seconds
```

### 3D Mesh `many_cubes --benchmark --material-texture-count 10`

<img width="1404" alt="Screenshot 2023-09-03 at 23 45 18"
src="https://github.com/bevyengine/bevy/assets/302146/5ee9c447-5bd2-45c6-9706-ac5ff8916daf">
This run uses 10 different materials by varying their textures. The
materials are randomly selected, and there is no sorting by material
bind group for opaque 3D so any batching is 'random'. The PR produces a
~5% reduction in median frame time. If we were to sort the opaque phase
by the material bind group, then this should be a lot faster. This
produces about 10.5k draws for the 11.7k visible entities. This makes
sense as randomly selecting from 10 materials gives a chance that two
adjacent entities randomly select the same material and can be batched.

The 1000th frame is identical in flip:

![flip many_cubes-main-mesh3d-mtc10 many_cubes-batching-mesh3d-mtc10
67ppd
ldr](https://github.com/bevyengine/bevy/assets/302146/2b3a8614-9466-4ed8-b50c-d4aa71615dbb)

```
     Mean: 0.000000
     Weighted median: 0.000000
     1st weighted quartile: 0.000000
     3rd weighted quartile: 0.000000
     Min: 0.000000
     Max: 0.000000
     Evaluation time: 0.4537 seconds
```

### 3D Mesh `many_cubes --benchmark --vary-per-instance`

<img width="1394" alt="Screenshot 2023-09-03 at 23 48 44"
src="https://github.com/bevyengine/bevy/assets/302146/f02a816b-a444-4c18-a96a-63b5436f3b7f">
This run varies the material data per instance by randomly-generating
its colour. This is the worst case for batching and that it performs
about the same as `main` is a good thing as it demonstrates that the
batching has minimal overhead when dealing with ~11k visible mesh
entities.

The 1000th frame is identical according to flip:

![flip many_cubes-main-mesh3d-vpi many_cubes-batching-mesh3d-vpi 67ppd
ldr](https://github.com/bevyengine/bevy/assets/302146/ac5f5c14-9bda-4d1a-8219-7577d4aac68c)

```
     Mean: 0.000000
     Weighted median: 0.000000
     1st weighted quartile: 0.000000
     3rd weighted quartile: 0.000000
     Min: 0.000000
     Max: 0.000000
     Evaluation time: 0.4568 seconds
```

### 2D Mesh `bevymark --benchmark --waves 160 --per-wave 1000 --mode
mesh2d`

<img width="1412" alt="Screenshot 2023-09-03 at 23 59 56"
src="https://github.com/bevyengine/bevy/assets/302146/cb02ae07-237b-4646-ae9f-fda4dafcbad4">
This spawns 160 waves of 1000 quad meshes that are shaded with
ColorMaterial. Each wave has a different material so 160 waves currently
should result in 160 batches. This results in a 50% reduction in median
frame time.

Capturing a screenshot of the 1000th frame main vs PR gives:

![flip bevymark-main-mesh2d bevymark-batching-mesh2d 67ppd
ldr](https://github.com/bevyengine/bevy/assets/302146/80102728-1217-4059-87af-14d05044df40)

```
     Mean: 0.001222
     Weighted median: 0.750432
     1st weighted quartile: 0.453494
     3rd weighted quartile: 0.969758
     Min: 0.000000
     Max: 0.990296
     Evaluation time: 0.4255 seconds
```

So they seem to produce the same results. I also double-checked the
number of draws. `main` does 160000 draws, and the PR does 160, as
expected.

### 2D Mesh `bevymark --benchmark --waves 160 --per-wave 1000 --mode
mesh2d --material-texture-count 10`

<img width="1392" alt="Screenshot 2023-09-04 at 00 09 22"
src="https://github.com/bevyengine/bevy/assets/302146/4358da2e-ce32-4134-82df-3ab74c40849c">
This generates 10 textures and generates materials for each of those and
then selects one material per wave. The median frame time is reduced by
50%. Similar to the plain run above, this produces 160 draws on the PR
and 160000 on `main` and the 1000th frame is identical (ignoring the fps
counter text overlay).

![flip bevymark-main-mesh2d-mtc10 bevymark-batching-mesh2d-mtc10 67ppd
ldr](https://github.com/bevyengine/bevy/assets/302146/ebed2822-dce7-426a-858b-b77dc45b986f)

```
     Mean: 0.002877
     Weighted median: 0.964980
     1st weighted quartile: 0.668871
     3rd weighted quartile: 0.982749
     Min: 0.000000
     Max: 0.992377
     Evaluation time: 0.4301 seconds
```

### 2D Mesh `bevymark --benchmark --waves 160 --per-wave 1000 --mode
mesh2d --vary-per-instance`

<img width="1396" alt="Screenshot 2023-09-04 at 00 13 53"
src="https://github.com/bevyengine/bevy/assets/302146/b2198b18-3439-47ad-919a-cdabe190facb">
This creates unique materials per instance by randomly-generating the
material's colour. This is the worst case for 2D batching. Somehow, this
PR manages a 7% reduction in median frame time. Both main and this PR
issue 160000 draws.

The 1000th frame is the same:

![flip bevymark-main-mesh2d-vpi bevymark-batching-mesh2d-vpi 67ppd
ldr](https://github.com/bevyengine/bevy/assets/302146/a2ec471c-f576-4a36-a23b-b24b22578b97)

```
     Mean: 0.001214
     Weighted median: 0.937499
     1st weighted quartile: 0.635467
     3rd weighted quartile: 0.979085
     Min: 0.000000
     Max: 0.988971
     Evaluation time: 0.4462 seconds
```

### 2D Sprite `bevymark --benchmark --waves 160 --per-wave 1000 --mode
sprite`

<img width="1396" alt="Screenshot 2023-09-04 at 12 21 12"
src="https://github.com/bevyengine/bevy/assets/302146/8b31e915-d6be-4cac-abf5-c6a4da9c3d43">
This just spawns 160 waves of 1000 sprites. There should be and is no
notable difference between main and the PR.

### 2D Sprite `bevymark --benchmark --waves 160 --per-wave 1000 --mode
sprite --material-texture-count 10`

<img width="1389" alt="Screenshot 2023-09-04 at 12 36 08"
src="https://github.com/bevyengine/bevy/assets/302146/45fe8d6d-c901-4062-a349-3693dd044413">
This spawns the sprites selecting a texture at random per instance from
the 10 generated textures. This has no significant change vs main and
shouldn't.

### 2D Sprite `bevymark --benchmark --waves 160 --per-wave 1000 --mode
sprite --vary-per-instance`

<img width="1401" alt="Screenshot 2023-09-04 at 12 29 52"
src="https://github.com/bevyengine/bevy/assets/302146/762c5c60-352e-471f-8dbe-bbf10e24ebd6">
This sets the sprite colour as being unique per instance. This can still
all be drawn using one batch. There should be no difference but the PR
produces median frame times that are 4% higher. Investigation showed no
clear sources of cost, rather a mix of give and take that should not
happen. It seems like noise in the results.

### Summary

| Benchmark  | % change in median frame time |
| ------------- | ------------- |
| many_cubes  | 🟩 -30%  |
| many_cubes 10 materials  | 🟩 -5%  |
| many_cubes unique materials  | 🟩 ~0%  |
| bevymark mesh2d  | 🟩 -50%  |
| bevymark mesh2d 10 materials  | 🟩 -50%  |
| bevymark mesh2d unique materials  | 🟩 -7%  |
| bevymark sprite  | 🟥 2%  |
| bevymark sprite 10 materials  | 🟥 0.6%  |
| bevymark sprite unique materials  | 🟥 4.1%  |

---

## Changelog

- Added: 2D and 3D mesh entities that share the same mesh and material
(same textures, same data) are now batched into the same draw command
for better performance.

---------

Co-authored-by: robtfm <50659922+robtfm@users.noreply.github.com>
Co-authored-by: Nicola Papale <nico@nicopap.ch>
2023-09-21 22:12:34 +00:00
Nicola Papale
7163aabf29
Use a single line for of large binding lists (#9849)
# Objective

- When adding/removing bindings in large binding lists, git would
generate very difficult-to-read diffs

## Solution

- Move the `@group(X) @binding(Y)` into the same line as the binding
type declaration
2023-09-19 22:17:44 +00:00
Carter Anderson
5eb292dc10
Bevy Asset V2 (#8624)
# Bevy Asset V2 Proposal

## Why Does Bevy Need A New Asset System?

Asset pipelines are a central part of the gamedev process. Bevy's
current asset system is missing a number of features that make it
non-viable for many classes of gamedev. After plenty of discussions and
[a long community feedback
period](https://github.com/bevyengine/bevy/discussions/3972), we've
identified a number missing features:

* **Asset Preprocessing**: it should be possible to "preprocess" /
"compile" / "crunch" assets at "development time" rather than when the
game starts up. This enables offloading expensive work from deployed
apps, faster asset loading, less runtime memory usage, etc.
* **Per-Asset Loader Settings**: Individual assets cannot define their
own loaders that override the defaults. Additionally, they cannot
provide per-asset settings to their loaders. This is a huge limitation,
as many asset types don't provide all information necessary for Bevy
_inside_ the asset. For example, a raw PNG image says nothing about how
it should be sampled (ex: linear vs nearest).
* **Asset `.meta` files**: assets should have configuration files stored
adjacent to the asset in question, which allows the user to configure
asset-type-specific settings. These settings should be accessible during
the pre-processing phase. Modifying a `.meta` file should trigger a
re-processing / re-load of the asset. It should be possible to configure
asset loaders from the meta file.
* **Processed Asset Hot Reloading**: Changes to processed assets (or
their dependencies) should result in re-processing them and re-loading
the results in live Bevy Apps.
* **Asset Dependency Tracking**: The current bevy_asset has no good way
to wait for asset dependencies to load. It punts this as an exercise for
consumers of the loader apis, which is unreasonable and error prone.
There should be easy, ergonomic ways to wait for assets to load and
block some logic on an asset's entire dependency tree loading.
* **Runtime Asset Loading**: it should be (optionally) possible to load
arbitrary assets dynamically at runtime. This necessitates being able to
deploy and run the asset server alongside Bevy Apps on _all platforms_.
For example, we should be able to invoke the shader compiler at runtime,
stream scenes from sources like the internet, etc. To keep deployed
binaries (and startup times) small, the runtime asset server
configuration should be configurable with different settings compared to
the "pre processor asset server".
* **Multiple Backends**: It should be possible to load assets from
arbitrary sources (filesystems, the internet, remote asset serves, etc).
* **Asset Packing**: It should be possible to deploy assets in
compressed "packs", which makes it easier and more efficient to
distribute assets with Bevy Apps.
* **Asset Handoff**: It should be possible to hold a "live" asset
handle, which correlates to runtime data, without actually holding the
asset in memory. Ex: it must be possible to hold a reference to a GPU
mesh generated from a "mesh asset" without keeping the mesh data in CPU
memory
* **Per-Platform Processed Assets**: Different platforms and app
distributions have different capabilities and requirements. Some
platforms need lower asset resolutions or different asset formats to
operate within the hardware constraints of the platform. It should be
possible to define per-platform asset processing profiles. And it should
be possible to deploy only the assets required for a given platform.

These features have architectural implications that are significant
enough to require a full rewrite. The current Bevy Asset implementation
got us this far, but it can take us no farther. This PR defines a brand
new asset system that implements most of these features, while laying
the foundations for the remaining features to be built.

## Bevy Asset V2

Here is a quick overview of the features introduced in this PR.
* **Asset Preprocessing**: Preprocess assets at development time into
more efficient (and configurable) representations
* **Dependency Aware**: Dependencies required to process an asset are
tracked. If an asset's processed dependency changes, it will be
reprocessed
* **Hot Reprocessing/Reloading**: detect changes to asset source files,
reprocess them if they have changed, and then hot-reload them in Bevy
Apps.
* **Only Process Changes**: Assets are only re-processed when their
source file (or meta file) has changed. This uses hashing and timestamps
to avoid processing assets that haven't changed.
* **Transactional and Reliable**: Uses write-ahead logging (a technique
commonly used by databases) to recover from crashes / forced-exits.
Whenever possible it avoids full-reprocessing / only uncompleted
transactions will be reprocessed. When the processor is running in
parallel with a Bevy App, processor asset writes block Bevy App asset
reads. Reading metadata + asset bytes is guaranteed to be transactional
/ correctly paired.
* **Portable / Run anywhere / Database-free**: The processor does not
rely on an in-memory database (although it uses some database techniques
for reliability). This is important because pretty much all in-memory
databases have unsupported platforms or build complications.
* **Configure Processor Defaults Per File Type**: You can say "use this
processor for all files of this type".
* **Custom Processors**: The `Processor` trait is flexible and
unopinionated. It can be implemented by downstream plugins.
* **LoadAndSave Processors**: Most asset processing scenarios can be
expressed as "run AssetLoader A, save the results using AssetSaver X,
and then load the result using AssetLoader B". For example, load this
png image using `PngImageLoader`, which produces an `Image` asset and
then save it using `CompressedImageSaver` (which also produces an
`Image` asset, but in a compressed format), which takes an `Image` asset
as input. This means if you have an `AssetLoader` for an asset, you are
already half way there! It also means that you can share AssetSavers
across multiple loaders. Because `CompressedImageSaver` accepts Bevy's
generic Image asset as input, it means you can also use it with some
future `JpegImageLoader`.
* **Loader and Saver Settings**: Asset Loaders and Savers can now define
their own settings types, which are passed in as input when an asset is
loaded / saved. Each asset can define its own settings.
* **Asset `.meta` files**: configure asset loaders, their settings,
enable/disable processing, and configure processor settings
* **Runtime Asset Dependency Tracking** Runtime asset dependencies (ex:
if an asset contains a `Handle<Image>`) are tracked by the asset server.
An event is emitted when an asset and all of its dependencies have been
loaded
* **Unprocessed Asset Loading**: Assets do not require preprocessing.
They can be loaded directly. A processed asset is just a "normal" asset
with some extra metadata. Asset Loaders don't need to know or care about
whether or not an asset was processed.
* **Async Asset IO**: Asset readers/writers use async non-blocking
interfaces. Note that because Rust doesn't yet support async traits,
there is a bit of manual Boxing / Future boilerplate. This will
hopefully be removed in the near future when Rust gets async traits.
* **Pluggable Asset Readers and Writers**: Arbitrary asset source
readers/writers are supported, both by the processor and the asset
server.
* **Better Asset Handles**
* **Single Arc Tree**: Asset Handles now use a single arc tree that
represents the lifetime of the asset. This makes their implementation
simpler, more efficient, and allows us to cheaply attach metadata to
handles. Ex: the AssetPath of a handle is now directly accessible on the
handle itself!
* **Const Typed Handles**: typed handles can be constructed in a const
context. No more weird "const untyped converted to typed at runtime"
patterns!
* **Handles and Ids are Smaller / Faster To Hash / Compare**: Typed
`Handle<T>` is now much smaller in memory and `AssetId<T>` is even
smaller.
* **Weak Handle Usage Reduction**: In general Handles are now considered
to be "strong". Bevy features that previously used "weak `Handle<T>`"
have been ported to `AssetId<T>`, which makes it statically clear that
the features do not hold strong handles (while retaining strong type
information). Currently Handle::Weak still exists, but it is very
possible that we can remove that entirely.
* **Efficient / Dense Asset Ids**: Assets now have efficient dense
runtime asset ids, which means we can avoid expensive hash lookups.
Assets are stored in Vecs instead of HashMaps. There are now typed and
untyped ids, which means we no longer need to store dynamic type
information in the ID for typed handles. "AssetPathId" (which was a
nightmare from a performance and correctness standpoint) has been
entirely removed in favor of dense ids (which are retrieved for a path
on load)
* **Direct Asset Loading, with Dependency Tracking**: Assets that are
defined at runtime can still have their dependencies tracked by the
Asset Server (ex: if you create a material at runtime, you can still
wait for its textures to load). This is accomplished via the (currently
optional) "asset dependency visitor" trait. This system can also be used
to define a set of assets to load, then wait for those assets to load.
* **Async folder loading**: Folder loading also uses this system and
immediately returns a handle to the LoadedFolder asset, which means
folder loading no longer blocks on directory traversals.
* **Improved Loader Interface**: Loaders now have a specific "top level
asset type", which makes returning the top-level asset simpler and
statically typed.
* **Basic Image Settings and Processing**: Image assets can now be
processed into the gpu-friendly Basic Universal format. The ImageLoader
now has a setting to define what format the image should be loaded as.
Note that this is just a minimal MVP ... plenty of additional work to do
here. To demo this, enable the `basis-universal` feature and turn on
asset processing.
* **Simpler Audio Play / AudioSink API**: Asset handle providers are
cloneable, which means the Audio resource can mint its own handles. This
means you can now do `let sink_handle = audio.play(music)` instead of
`let sink_handle = audio_sinks.get_handle(audio.play(music))`. Note that
this might still be replaced by
https://github.com/bevyengine/bevy/pull/8424.
**Removed Handle Casting From Engine Features**: Ex: FontAtlases no
longer use casting between handle types

## Using The New Asset System

### Normal Unprocessed Asset Loading

By default the `AssetPlugin` does not use processing. It behaves pretty
much the same way as the old system.

If you are defining a custom asset, first derive `Asset`:

```rust
#[derive(Asset)]
struct Thing {
    value: String,
}
```

Initialize the asset:
```rust
app.init_asset:<Thing>()
```

Implement a new `AssetLoader` for it:

```rust
#[derive(Default)]
struct ThingLoader;

#[derive(Serialize, Deserialize, Default)]
pub struct ThingSettings {
    some_setting: bool,
}

impl AssetLoader for ThingLoader {
    type Asset = Thing;
    type Settings = ThingSettings;

    fn load<'a>(
        &'a self,
        reader: &'a mut Reader,
        settings: &'a ThingSettings,
        load_context: &'a mut LoadContext,
    ) -> BoxedFuture<'a, Result<Thing, anyhow::Error>> {
        Box::pin(async move {
            let mut bytes = Vec::new();
            reader.read_to_end(&mut bytes).await?;
            // convert bytes to value somehow
            Ok(Thing {
                value 
            })
        })
    }

    fn extensions(&self) -> &[&str] {
        &["thing"]
    }
}
```

Note that this interface will get much cleaner once Rust gets support
for async traits. `Reader` is an async futures_io::AsyncRead. You can
stream bytes as they come in or read them all into a `Vec<u8>`,
depending on the context. You can use `let handle =
load_context.load(path)` to kick off a dependency load, retrieve a
handle, and register the dependency for the asset.

Then just register the loader in your Bevy app:

```rust
app.init_asset_loader::<ThingLoader>()
```

Now just add your `Thing` asset files into the `assets` folder and load
them like this:

```rust
fn system(asset_server: Res<AssetServer>) {
    let handle = Handle<Thing> = asset_server.load("cool.thing");
}
```

You can check load states directly via the asset server:

```rust
if asset_server.load_state(&handle) == LoadState::Loaded { }
```

You can also listen for events:

```rust
fn system(mut events: EventReader<AssetEvent<Thing>>, handle: Res<SomeThingHandle>) {
    for event in events.iter() {
        if event.is_loaded_with_dependencies(&handle) {
        }
    }
}
```

Note the new `AssetEvent::LoadedWithDependencies`, which only fires when
the asset is loaded _and_ all dependencies (and their dependencies) have
loaded.

Unlike the old asset system, for a given asset path all `Handle<T>`
values point to the same underlying Arc. This means Handles can cheaply
hold more asset information, such as the AssetPath:

```rust
// prints the AssetPath of the handle
info!("{:?}", handle.path())
```

### Processed Assets

Asset processing can be enabled via the `AssetPlugin`. When developing
Bevy Apps with processed assets, do this:

```rust
app.add_plugins(DefaultPlugins.set(AssetPlugin::processed_dev()))
```

This runs the `AssetProcessor` in the background with hot-reloading. It
reads assets from the `assets` folder, processes them, and writes them
to the `.imported_assets` folder. Asset loads in the Bevy App will wait
for a processed version of the asset to become available. If an asset in
the `assets` folder changes, it will be reprocessed and hot-reloaded in
the Bevy App.

When deploying processed Bevy apps, do this:

```rust
app.add_plugins(DefaultPlugins.set(AssetPlugin::processed()))
```

This does not run the `AssetProcessor` in the background. It behaves
like `AssetPlugin::unprocessed()`, but reads assets from
`.imported_assets`.

When the `AssetProcessor` is running, it will populate sibling `.meta`
files for assets in the `assets` folder. Meta files for assets that do
not have a processor configured look like this:

```rust
(
    meta_format_version: "1.0",
    asset: Load(
        loader: "bevy_render::texture::image_loader::ImageLoader",
        settings: (
            format: FromExtension,
        ),
    ),
)
```

This is metadata for an image asset. For example, if you have
`assets/my_sprite.png`, this could be the metadata stored at
`assets/my_sprite.png.meta`. Meta files are totally optional. If no
metadata exists, the default settings will be used.

In short, this file says "load this asset with the ImageLoader and use
the file extension to determine the image type". This type of meta file
is supported in all AssetPlugin modes. If in `Unprocessed` mode, the
asset (with the meta settings) will be loaded directly. If in
`ProcessedDev` mode, the asset file will be copied directly to the
`.imported_assets` folder. The meta will also be copied directly to the
`.imported_assets` folder, but with one addition:

```rust
(
    meta_format_version: "1.0",
    processed_info: Some((
        hash: 12415480888597742505,
        full_hash: 14344495437905856884,
        process_dependencies: [],
    )),
    asset: Load(
        loader: "bevy_render::texture::image_loader::ImageLoader",
        settings: (
            format: FromExtension,
        ),
    ),
)
```

`processed_info` contains `hash` (a direct hash of the asset and meta
bytes), `full_hash` (a hash of `hash` and the hashes of all
`process_dependencies`), and `process_dependencies` (the `path` and
`full_hash` of every process_dependency). A "process dependency" is an
asset dependency that is _directly_ used when processing the asset.
Images do not have process dependencies, so this is empty.

When the processor is enabled, you can use the `Process` metadata
config:

```rust
(
    meta_format_version: "1.0",
    asset: Process(
        processor: "bevy_asset::processor::process::LoadAndSave<bevy_render::texture::image_loader::ImageLoader, bevy_render::texture::compressed_image_saver::CompressedImageSaver>",
        settings: (
            loader_settings: (
                format: FromExtension,
            ),
            saver_settings: (
                generate_mipmaps: true,
            ),
        ),
    ),
)
```

This configures the asset to use the `LoadAndSave` processor, which runs
an AssetLoader and feeds the result into an AssetSaver (which saves the
given Asset and defines a loader to load it with). (for terseness
LoadAndSave will likely get a shorter/friendlier type name when [Stable
Type Paths](#7184) lands). `LoadAndSave` is likely to be the most common
processor type, but arbitrary processors are supported.

`CompressedImageSaver` saves an `Image` in the Basis Universal format
and configures the ImageLoader to load it as basis universal. The
`AssetProcessor` will read this meta, run it through the LoadAndSave
processor, and write the basis-universal version of the image to
`.imported_assets`. The final metadata will look like this:

```rust
(
    meta_format_version: "1.0",
    processed_info: Some((
        hash: 905599590923828066,
        full_hash: 9948823010183819117,
        process_dependencies: [],
    )),
    asset: Load(
        loader: "bevy_render::texture::image_loader::ImageLoader",
        settings: (
            format: Format(Basis),
        ),
    ),
)
```

To try basis-universal processing out in Bevy examples, (for example
`sprite.rs`), change `add_plugins(DefaultPlugins)` to
`add_plugins(DefaultPlugins.set(AssetPlugin::processed_dev()))` and run
with the `basis-universal` feature enabled: `cargo run
--features=basis-universal --example sprite`.

To create a custom processor, there are two main paths:
1. Use the `LoadAndSave` processor with an existing `AssetLoader`.
Implement the `AssetSaver` trait, register the processor using
`asset_processor.register_processor::<LoadAndSave<ImageLoader,
CompressedImageSaver>>(image_saver.into())`.
2. Implement the `Process` trait directly and register it using:
`asset_processor.register_processor(thing_processor)`.

You can configure default processors for file extensions like this:

```rust
asset_processor.set_default_processor::<ThingProcessor>("thing")
```

There is one more metadata type to be aware of:

```rust
(
    meta_format_version: "1.0",
    asset: Ignore,
)
```

This will ignore the asset during processing / prevent it from being
written to `.imported_assets`.

The AssetProcessor stores a transaction log at `.imported_assets/log`
and uses it to gracefully recover from unexpected stops. This means you
can force-quit the processor (and Bevy Apps running the processor in
parallel) at arbitrary times!

`.imported_assets` is "local state". It should _not_ be checked into
source control. It should also be considered "read only". In practice,
you _can_ modify processed assets and processed metadata if you really
need to test something. But those modifications will not be represented
in the hashes of the assets, so the processed state will be "out of
sync" with the source assets. The processor _will not_ fix this for you.
Either revert the change after you have tested it, or delete the
processed files so they can be re-populated.

## Open Questions

There are a number of open questions to be discussed. We should decide
if they need to be addressed in this PR and if so, how we will address
them:

### Implied Dependencies vs Dependency Enumeration

There are currently two ways to populate asset dependencies:
* **Implied via AssetLoaders**: if an AssetLoader loads an asset (and
retrieves a handle), a dependency is added to the list.
* **Explicit via the optional Asset::visit_dependencies**: if
`server.load_asset(my_asset)` is called, it will call
`my_asset.visit_dependencies`, which will grab dependencies that have
been manually defined for the asset via the Asset trait impl (which can
be derived).

This means that defining explicit dependencies is optional for "loaded
assets". And the list of dependencies is always accurate because loaders
can only produce Handles if they register dependencies. If an asset was
loaded with an AssetLoader, it only uses the implied dependencies. If an
asset was created at runtime and added with
`asset_server.load_asset(MyAsset)`, it will use
`Asset::visit_dependencies`.

However this can create a behavior mismatch between loaded assets and
equivalent "created at runtime" assets if `Assets::visit_dependencies`
doesn't exactly match the dependencies produced by the AssetLoader. This
behavior mismatch can be resolved by completely removing "implied loader
dependencies" and requiring `Asset::visit_dependencies` to supply
dependency data. But this creates two problems:
* It makes defining loaded assets harder and more error prone: Devs must
remember to manually annotate asset dependencies with `#[dependency]`
when deriving `Asset`. For more complicated assets (such as scenes), the
derive likely wouldn't be sufficient and a manual `visit_dependencies`
impl would be required.
* Removes the ability to immediately kick off dependency loads: When
AssetLoaders retrieve a Handle, they also immediately kick off an asset
load for the handle, which means it can start loading in parallel
_before_ the asset finishes loading. For large assets, this could be
significant. (although this could be mitigated for processed assets if
we store dependencies in the processed meta file and load them ahead of
time)

### Eager ProcessorDev Asset Loading

I made a controversial call in the interest of fast startup times ("time
to first pixel") for the "processor dev mode configuration". When
initializing the AssetProcessor, current processed versions of unchanged
assets are yielded immediately, even if their dependencies haven't been
checked yet for reprocessing. This means that
non-current-state-of-filesystem-but-previously-valid assets might be
returned to the App first, then hot-reloaded if/when their dependencies
change and the asset is reprocessed.

Is this behavior desirable? There is largely one alternative: do not
yield an asset from the processor to the app until all of its
dependencies have been checked for changes. In some common cases (load
dependency has not changed since last run) this will increase startup
time. The main question is "by how much" and is that slower startup time
worth it in the interest of only yielding assets that are true to the
current state of the filesystem. Should this be configurable? I'm
starting to think we should only yield an asset after its (historical)
dependencies have been checked for changes + processed as necessary, but
I'm curious what you all think.

### Paths Are Currently The Only Canonical ID / Do We Want Asset UUIDs?

In this implementation AssetPaths are the only canonical asset
identifier (just like the previous Bevy Asset system and Godot). Moving
assets will result in re-scans (and currently reprocessing, although
reprocessing can easily be avoided with some changes). Asset
renames/moves will break code and assets that rely on specific paths,
unless those paths are fixed up.

Do we want / need "stable asset uuids"? Introducing them is very
possible:
1. Generate a UUID and include it in .meta files
2. Support UUID in AssetPath
3. Generate "asset indices" which are loaded on startup and map UUIDs to
paths.
4 (maybe). Consider only supporting UUIDs for processed assets so we can
generate quick-to-load indices instead of scanning meta files.

The main "pro" is that assets referencing UUIDs don't need to be
migrated when a path changes. The main "con" is that UUIDs cannot be
"lazily resolved" like paths. They need a full view of all assets to
answer the question "does this UUID exist". Which means UUIDs require
the AssetProcessor to fully finish startup scans before saying an asset
doesnt exist. And they essentially require asset pre-processing to use
in apps, because scanning all asset metadata files at runtime to resolve
a UUID is not viable for medium-to-large apps. It really requires a
pre-generated UUID index, which must be loaded before querying for
assets.

I personally think this should be investigated in a separate PR. Paths
aren't going anywhere ... _everyone_ uses filesystems (and
filesystem-like apis) to manage their asset source files. I consider
them permanent canonical asset information. Additionally, they behave
well for both processed and unprocessed asset modes. Given that Bevy is
supporting both, this feels like the right canonical ID to start with.
UUIDS (and maybe even other indexed-identifier types) can be added later
as necessary.

### Folder / File Naming Conventions

All asset processing config currently lives in the `.imported_assets`
folder. The processor transaction log is in `.imported_assets/log`.
Processed assets are added to `.imported_assets/Default`, which will
make migrating to processed asset profiles (ex: a
`.imported_assets/Mobile` profile) a non-breaking change. It also allows
us to create top-level files like `.imported_assets/log` without it
being interpreted as an asset. Meta files currently have a `.meta`
suffix. Do we like these names and conventions?

### Should the `AssetPlugin::processed_dev` configuration enable
`watch_for_changes` automatically?

Currently it does (which I think makes sense), but it does make it the
only configuration that enables watch_for_changes by default.

### Discuss on_loaded High Level Interface:

This PR includes a very rough "proof of concept" `on_loaded` system
adapter that uses the `LoadedWithDependencies` event in combination with
`asset_server.load_asset` dependency tracking to support this pattern

```rust
fn main() {
    App::new()
        .init_asset::<MyAssets>()
        .add_systems(Update, on_loaded(create_array_texture))
        .run();
}

#[derive(Asset, Clone)]
struct MyAssets {
    #[dependency]
    picture_of_my_cat: Handle<Image>,
    #[dependency]
    picture_of_my_other_cat: Handle<Image>,
}

impl FromWorld for ArrayTexture {
    fn from_world(world: &mut World) -> Self {
        picture_of_my_cat: server.load("meow.png"),
        picture_of_my_other_cat: server.load("meeeeeeeow.png"),
    }
}

fn spawn_cat(In(my_assets): In<MyAssets>, mut commands: Commands) {
    commands.spawn(SpriteBundle {
        texture: my_assets.picture_of_my_cat.clone(),  
        ..default()
    });
    
    commands.spawn(SpriteBundle {
        texture: my_assets.picture_of_my_other_cat.clone(),  
        ..default()
    });
}

```

The implementation is _very_ rough. And it is currently unsafe because
`bevy_ecs` doesn't expose some internals to do this safely from inside
`bevy_asset`. There are plenty of unanswered questions like:
* "do we add a Loadable" derive? (effectively automate the FromWorld
implementation above)
* Should `MyAssets` even be an Asset? (largely implemented this way
because it elegantly builds on `server.load_asset(MyAsset { .. })`
dependency tracking).

We should think hard about what our ideal API looks like (and if this is
a pattern we want to support). Not necessarily something we need to
solve in this PR. The current `on_loaded` impl should probably be
removed from this PR before merging.

## Clarifying Questions

### What about Assets as Entities?

This Bevy Asset V2 proposal implementation initially stored Assets as
ECS Entities. Instead of `AssetId<T>` + the `Assets<T>` resource it used
`Entity` as the asset id and Asset values were just ECS components.
There are plenty of compelling reasons to do this:
1. Easier to inline assets in Bevy Scenes (as they are "just" normal
entities + components)
2. More flexible queries: use the power of the ECS to filter assets (ex:
`Query<Mesh, With<Tree>>`).
3. Extensible. Users can add arbitrary component data to assets.
4. Things like "component visualization tools" work out of the box to
visualize asset data.

However Assets as Entities has a ton of caveats right now:
* We need to be able to allocate entity ids without a direct World
reference (aka rework id allocator in Entities ... i worked around this
in my prototypes by just pre allocating big chunks of entities)
* We want asset change events in addition to ECS change tracking ... how
do we populate them when mutations can come from anywhere? Do we use
Changed queries? This would require iterating over the change data for
all assets every frame. Is this acceptable or should we implement a new
"event based" component change detection option?
* Reconciling manually created assets with asset-system managed assets
has some nuance (ex: are they "loaded" / do they also have that
component metadata?)
* "how do we handle "static" / default entity handles" (ties in to the
Entity Indices discussion:
https://github.com/bevyengine/bevy/discussions/8319). This is necessary
for things like "built in" assets and default handles in things like
SpriteBundle.
* Storing asset information as a component makes it easy to "invalidate"
asset state by removing the component (or forcing modifications).
Ideally we have ways to lock this down (some combination of Rust type
privacy and ECS validation)

In practice, how we store and identify assets is a reasonably
superficial change (porting off of Assets as Entities and implementing
dedicated storage + ids took less than a day). So once we sort out the
remaining challenges the flip should be straightforward. Additionally, I
do still have "Assets as Entities" in my commit history, so we can reuse
that work. I personally think "assets as entities" is a good endgame,
but it also doesn't provide _significant_ value at the moment and it
certainly isn't ready yet with the current state of things.

### Why not Distill?

[Distill](https://github.com/amethyst/distill) is a high quality fully
featured asset system built in Rust. It is very natural to ask "why not
just use Distill?".

It is also worth calling out that for awhile, [we planned on adopting
Distill / I signed off on
it](https://github.com/bevyengine/bevy/issues/708).

However I think Bevy has a number of constraints that make Distill
adoption suboptimal:
* **Architectural Simplicity:**
* Distill's processor requires an in-memory database (lmdb) and RPC
networked API (using Cap'n Proto). Each of these introduces API
complexity that increases maintenance burden and "code grokability".
Ignoring tests, documentation, and examples, Distill has 24,237 lines of
Rust code (including generated code for RPC + database interactions). If
you ignore generated code, it has 11,499 lines.
* Bevy builds the AssetProcessor and AssetServer using pluggable
AssetReader/AssetWriter Rust traits with simple io interfaces. They do
not necessitate databases or RPC interfaces (although Readers/Writers
could use them if that is desired). Bevy Asset V2 (at the time of
writing this PR) is 5,384 lines of Rust code (ignoring tests,
documentation, and examples). Grain of salt: Distill does have more
features currently (ex: Asset Packing, GUIDS, remote-out-of-process
asset processor). I do plan to implement these features in Bevy Asset V2
and I personally highly doubt they will meaningfully close the 6115
lines-of-code gap.
* This complexity gap (which while illustrated by lines of code, is much
bigger than just that) is noteworthy to me. Bevy should be hackable and
there are pillars of Distill that are very hard to understand and
extend. This is a matter of opinion (and Bevy Asset V2 also has
complicated areas), but I think Bevy Asset V2 is much more approachable
for the average developer.
* Necessary disclaimer: counting lines of code is an extremely rough
complexity metric. Read the code and form your own opinions.
* **Optional Asset Processing:** Not all Bevy Apps (or Bevy App
developers) need / want asset preprocessing. Processing increases the
complexity of the development environment by introducing things like
meta files, imported asset storage, running processors in the
background, waiting for processing to finish, etc. Distill _requires_
preprocessing to work. With Bevy Asset V2 processing is fully opt-in.
The AssetServer isn't directly aware of asset processors at all.
AssetLoaders only care about converting bytes to runtime Assets ... they
don't know or care if the bytes were pre-processed or not. Processing is
"elegantly" (forgive my self-congratulatory phrasing) layered on top and
builds on the existing Asset system primitives.
* **Direct Filesystem Access to Processed Asset State:** Distill stores
processed assets in a database. This makes debugging / inspecting the
processed outputs harder (either requires special tooling to query the
database or they need to be "deployed" to be inspected). Bevy Asset V2,
on the other hand, stores processed assets in the filesystem (by default
... this is configurable). This makes interacting with the processed
state more natural. Note that both Godot and Unity's new asset system
store processed assets in the filesystem.
* **Portability**: Because Distill's processor uses lmdb and RPC
networking, it cannot be run on certain platforms (ex: lmdb is a
non-rust dependency that cannot run on the web, some platforms don't
support running network servers). Bevy should be able to process assets
everywhere (ex: run the Bevy Editor on the web, compile + process
shaders on mobile, etc). Distill does partially mitigate this problem by
supporting "streaming" assets via the RPC protocol, but this is not a
full solve from my perspective. And Bevy Asset V2 can (in theory) also
stream assets (without requiring RPC, although this isn't implemented
yet)

Note that I _do_ still think Distill would be a solid asset system for
Bevy. But I think the approach in this PR is a better solve for Bevy's
specific "asset system requirements".

### Doesn't async-fs just shim requests to "sync" `std::fs`? What is the
point?

"True async file io" has limited / spotty platform support. async-fs
(and the rust async ecosystem generally ... ex Tokio) currently use
async wrappers over std::fs that offload blocking requests to separate
threads. This may feel unsatisfying, but it _does_ still provide value
because it prevents our task pools from blocking on file system
operations (which would prevent progress when there are many tasks to
do, but all threads in a pool are currently blocking on file system
ops).

Additionally, using async APIs for our AssetReaders and AssetWriters
also provides value because we can later add support for "true async
file io" for platforms that support it. _And_ we can implement other
"true async io" asset backends (such as networked asset io).

## Draft TODO

- [x] Fill in missing filesystem event APIs: file removed event (which
is expressed as dangling RenameFrom events in some cases), file/folder
renamed event
- [x] Assets without loaders are not moved to the processed folder. This
breaks things like referenced `.bin` files for GLTFs. This should be
configurable per-non-asset-type.
- [x] Initial implementation of Reflect and FromReflect for Handle. The
"deserialization" parity bar is low here as this only worked with static
UUIDs in the old impl ... this is a non-trivial problem. Either we add a
Handle::AssetPath variant that gets "upgraded" to a strong handle on
scene load or we use a separate AssetRef type for Bevy scenes (which is
converted to a runtime Handle on load). This deserves its own discussion
in a different pr.
- [x] Populate read_asset_bytes hash when run by the processor (a bit of
a special case .. when run by the processor the processed meta will
contain the hash so we don't need to compute it on the spot, but we
don't want/need to read the meta when run by the main AssetServer)
- [x] Delay hot reloading: currently filesystem events are handled
immediately, which creates timing issues in some cases. For example hot
reloading images can sometimes break because the image isn't finished
writing. We should add a delay, likely similar to the [implementation in
this PR](https://github.com/bevyengine/bevy/pull/8503).
- [x] Port old platform-specific AssetIo implementations to the new
AssetReader interface (currently missing Android and web)
- [x] Resolve on_loaded unsafety (either by removing the API entirely or
removing the unsafe)
- [x]  Runtime loader setting overrides
- [x] Remove remaining unwraps that should be error-handled. There are
number of TODOs here
- [x] Pretty AssetPath Display impl
- [x] Document more APIs
- [x] Resolve spurious "reloading because it has changed" events (to
repro run load_gltf with `processed_dev()`)
- [x] load_dependency hot reloading currently only works for processed
assets. If processing is disabled, load_dependency changes are not hot
reloaded.
- [x] Replace AssetInfo dependency load/fail counters with
`loading_dependencies: HashSet<UntypedAssetId>` to prevent reloads from
(potentially) breaking counters. Storing this will also enable
"dependency reloaded" events (see [Next Steps](#next-steps))
- [x] Re-add filesystem watcher cargo feature gate (currently it is not
optional)
- [ ] Migration Guide
- [ ] Changelog

## Followup TODO

- [ ] Replace "eager unchanged processed asset loading" behavior with
"don't returned unchanged processed asset until dependencies have been
checked".
- [ ] Add true `Ignore` AssetAction that does not copy the asset to the
imported_assets folder.
- [ ] Finish "live asset unloading" (ex: free up CPU asset memory after
uploading an image to the GPU), rethink RenderAssets, and port renderer
features. The `Assets` collection uses `Option<T>` for asset storage to
support its removal. (1) the Option might not actually be necessary ...
might be able to just remove from the collection entirely (2) need to
finalize removal apis
- [ ] Try replacing the "channel based" asset id recycling with
something a bit more efficient (ex: we might be able to use raw atomic
ints with some cleverness)
- [ ] Consider adding UUIDs to processed assets (scoped just to helping
identify moved assets ... not exposed to load queries ... see [Next
Steps](#next-steps))
- [ ] Store "last modified" source asset and meta timestamps in
processed meta files to enable skipping expensive hashing when the file
wasn't changed
- [ ] Fix "slow loop" handle drop fix 
- [ ] Migrate to TypeName
- [x] Handle "loader preregistration". See #9429

## Next Steps

* **Configurable per-type defaults for AssetMeta**: It should be
possible to add configuration like "all png image meta should default to
using nearest sampling" (currently this hard-coded per-loader/processor
Settings::default() impls). Also see the "Folder Meta" bullet point.
* **Avoid Reprocessing on Asset Renames / Moves**: See the "canonical
asset ids" discussion in [Open Questions](#open-questions) and the
relevant bullet point in [Draft TODO](#draft-todo). Even without
canonical ids, folder renames could avoid reprocessing in some cases.
* **Multiple Asset Sources**: Expand AssetPath to support "asset source
names" and support multiple AssetReaders in the asset server (ex:
`webserver://some_path/image.png` backed by an Http webserver
AssetReader). The "default" asset reader would use normal
`some_path/image.png` paths. Ideally this works in combination with
multiple AssetWatchers for hot-reloading
* **Stable Type Names**: this pr removes the TypeUuid requirement from
assets in favor of `std::any::type_name`. This makes defining assets
easier (no need to generate a new uuid / use weird proc macro syntax).
It also makes reading meta files easier (because things have "friendly
names"). We also use type names for components in scene files. If they
are good enough for components, they are good enough for assets. And
consistency across Bevy pillars is desirable. However,
`std::any::type_name` is not guaranteed to be stable (although in
practice it is). We've developed a [stable type
path](https://github.com/bevyengine/bevy/pull/7184) to resolve this,
which should be adopted when it is ready.
* **Command Line Interface**: It should be possible to run the asset
processor in a separate process from the command line. This will also
require building a network-server-backed AssetReader to communicate
between the app and the processor. We've been planning to build a "bevy
cli" for awhile. This seems like a good excuse to build it.
* **Asset Packing**: This is largely an additive feature, so it made
sense to me to punt this until we've laid the foundations in this PR.
* **Per-Platform Processed Assets**: It should be possible to generate
assets for multiple platforms by supporting multiple "processor
profiles" per asset (ex: compress with format X on PC and Y on iOS). I
think there should probably be arbitrary "profiles" (which can be
separate from actual platforms), which are then assigned to a given
platform when generating the final asset distribution for that platform.
Ex: maybe devs want a "Mobile" profile that is shared between iOS and
Android. Or a "LowEnd" profile shared between web and mobile.
* **Versioning and Migrations**: Assets, Loaders, Savers, and Processors
need to have versions to determine if their schema is valid. If an asset
/ loader version is incompatible with the current version expected at
runtime, the processor should be able to migrate them. I think we should
try using Bevy Reflect for this, as it would allow us to load the old
version as a dynamic Reflect type without actually having the old Rust
type. It would also allow us to define "patches" to migrate between
versions (Bevy Reflect devs are currently working on patching). The
`.meta` file already has its own format version. Migrating that to new
versions should also be possible.
* **Real Copy-on-write AssetPaths**: Rust's actual Cow (clone-on-write
type) currently used by AssetPath can still result in String clones that
aren't actually necessary (cloning an Owned Cow clones the contents).
Bevy's asset system requires cloning AssetPaths in a number of places,
which result in actual clones of the internal Strings. This is not
efficient. AssetPath internals should be reworked to exhibit truer
cow-like-behavior that reduces String clones to the absolute minimum.
* **Consider processor-less processing**: In theory the AssetServer
could run processors "inline" even if the background AssetProcessor is
disabled. If we decide this is actually desirable, we could add this.
But I don't think its a priority in the short or medium term.
* **Pre-emptive dependency loading**: We could encode dependencies in
processed meta files, which could then be used by the Asset Server to
kick of dependency loads as early as possible (prior to starting the
actual asset load). Is this desirable? How much time would this save in
practice?
* **Optimize Processor With UntypedAssetIds**: The processor exclusively
uses AssetPath to identify assets currently. It might be possible to
swap these out for UntypedAssetIds in some places, which are smaller /
cheaper to hash and compare.
* **One to Many Asset Processing**: An asset source file that produces
many assets currently must be processed into a single "processed" asset
source. If labeled assets can be written separately they can each have
their own configured savers _and_ they could be loaded more granularly.
Definitely worth exploring!
* **Automatically Track "Runtime-only" Asset Dependencies**: Right now,
tracking "created at runtime" asset dependencies requires adding them
via `asset_server.load_asset(StandardMaterial::default())`. I think with
some cleverness we could also do this for
`materials.add(StandardMaterial::default())`, making tracking work
"everywhere". There are challenges here relating to change detection /
ensuring the server is made aware of dependency changes. This could be
expensive in some cases.
* **"Dependency Changed" events**: Some assets have runtime artifacts
that need to be re-generated when one of their dependencies change (ex:
regenerate a material's bind group when a Texture needs to change). We
are generating the dependency graph so we can definitely produce these
events. Buuuuut generating these events will have a cost / they could be
high frequency for some assets, so we might want this to be opt-in for
specific cases.
* **Investigate Storing More Information In Handles**: Handles can now
store arbitrary information, which makes it cheaper and easier to
access. How much should we move into them? Canonical asset load states
(via atomics)? (`handle.is_loaded()` would be very cool). Should we
store the entire asset and remove the `Assets<T>` collection?
(`Arc<RwLock<Option<Image>>>`?)
* **Support processing and loading files without extensions**: This is a
pretty arbitrary restriction and could be supported with very minimal
changes.
* **Folder Meta**: It would be nice if we could define per folder
processor configuration defaults (likely in a `.meta` or `.folder_meta`
file). Things like "default to linear filtering for all Images in this
folder".
* **Replace async_broadcast with event-listener?** This might be
approximately drop-in for some uses and it feels more light weight
* **Support Running the AssetProcessor on the Web**: Most of the hard
work is done here, but there are some easy straggling TODOs (make the
transaction log an interface instead of a direct file writer so we can
write a web storage backend, implement an AssetReader/AssetWriter that
reads/writes to something like LocalStorage).
* **Consider identifying and preventing circular dependencies**: This is
especially important for "processor dependencies", as processing will
silently never finish in these cases.
* **Built-in/Inlined Asset Hot Reloading**: This PR regresses
"built-in/inlined" asset hot reloading (previously provided by the
DebugAssetServer). I'm intentionally punting this because I think it can
be cleanly implemented with "multiple asset sources" by registering a
"debug asset source" (ex: `debug://bevy_pbr/src/render/pbr.wgsl` asset
paths) in combination with an AssetWatcher for that asset source and
support for "manually loading pats with asset bytes instead of
AssetReaders". The old DebugAssetServer was quite nasty and I'd love to
avoid that hackery going forward.
* **Investigate ways to remove double-parsing meta files**: Parsing meta
files currently involves parsing once with "minimal" versions of the
meta file to extract the type name of the loader/processor config, then
parsing again to parse the "full" meta. This is suboptimal. We should be
able to define custom deserializers that (1) assume the loader/processor
type name comes first (2) dynamically looks up the loader/processor
registrations to deserialize settings in-line (similar to components in
the bevy scene format). Another alternative: deserialize as dynamic
Reflect objects and then convert.
* **More runtime loading configuration**: Support using the Handle type
as a hint to select an asset loader (instead of relying on AssetPath
extensions)
* **More high level Processor trait implementations**: For example, it
might be worth adding support for arbitrary chains of "asset transforms"
that modify an in-memory asset representation between loading and
saving. (ex: load a Mesh, run a `subdivide_mesh` transform, followed by
a `flip_normals` transform, then save the mesh to an efficient
compressed format).
* **Bevy Scene Handle Deserialization**: (see the relevant [Draft TODO
item](#draft-todo) for context)
* **Explore High Level Load Interfaces**: See [this
discussion](#discuss-on_loaded-high-level-interface) for one prototype.
* **Asset Streaming**: It would be great if we could stream Assets (ex:
stream a long video file piece by piece)
* **ID Exchanging**: In this PR Asset Handles/AssetIds are bigger than
they need to be because they have a Uuid enum variant. If we implement
an "id exchanging" system that trades Uuids for "efficient runtime ids",
we can cut down on the size of AssetIds, making them more efficient.
This has some open design questions, such as how to spawn entities with
"default" handle values (as these wouldn't have access to the exchange
api in the current system).
* **Asset Path Fixup Tooling**: Assets that inline asset paths inside
them will break when an asset moves. The asset system provides the
functionality to detect when paths break. We should build a framework
that enables formats to define "path migrations". This is especially
important for scene files. For editor-generated files, we should also
consider using UUIDs (see other bullet point) to avoid the need to
migrate in these cases.

---------

Co-authored-by: BeastLe9enD <beastle9end@outlook.de>
Co-authored-by: Mike <mike.hsu@gmail.com>
Co-authored-by: Nicola Papale <nicopap@users.noreply.github.com>
2023-09-07 02:07:27 +00:00
Joseph
02b520b4e8
Split ComputedVisibility into two components to allow for accurate change detection and speed up visibility propagation (#9497)
# Objective

Fix #8267.
Fixes half of #7840.

The `ComputedVisibility` component contains two flags: hierarchy
visibility, and view visibility (whether its visible to any cameras).
Due to the modular and open-ended way that view visibility is computed,
it triggers change detection every single frame, even when the value
does not change. Since hierarchy visibility is stored in the same
component as view visibility, this means that change detection for
inherited visibility is completely broken.

At the company I work for, this has become a real issue. We are using
change detection to only re-render scenes when necessary. The broken
state of change detection for computed visibility means that we have to
to rely on the non-inherited `Visibility` component for now. This is
workable in the early stages of our project, but since we will
inevitably want to use the hierarchy, we will have to either:

1. Roll our own solution for computed visibility.
2. Fix the issue for everyone.

## Solution

Split the `ComputedVisibility` component into two: `InheritedVisibilty`
and `ViewVisibility`.
This allows change detection to behave properly for
`InheritedVisibility`.
View visiblity is still erratic, although it is less useful to be able
to detect changes
for this flavor of visibility.

Overall, this actually simplifies the API. Since the visibility system
consists of
self-explaining components, it is much easier to document the behavior
and usage.
This approach is more modular and "ECS-like" -- one could
strip out the `ViewVisibility` component entirely if it's not needed,
and rely only on inherited visibility.

---

## Changelog

- `ComputedVisibility` has been removed in favor of:
`InheritedVisibility` and `ViewVisiblity`.

## Migration Guide

The `ComputedVisibilty` component has been split into
`InheritedVisiblity` and
`ViewVisibility`. Replace any usages of
`ComputedVisibility::is_visible_in_hierarchy`
with `InheritedVisibility::get`, and replace
`ComputedVisibility::is_visible_in_view`
 with `ViewVisibility::get`.
 
 ```rust
 // Before:
 commands.spawn(VisibilityBundle {
     visibility: Visibility::Inherited,
     computed_visibility: ComputedVisibility::default(),
 });
 
 // After:
 commands.spawn(VisibilityBundle {
     visibility: Visibility::Inherited,
     inherited_visibility: InheritedVisibility::default(),
     view_visibility: ViewVisibility::default(),
 });
 ```
 
 ```rust
 // Before:
 fn my_system(q: Query<&ComputedVisibilty>) {
     for vis in &q {
         if vis.is_visible_in_hierarchy() {
     
 // After:
 fn my_system(q: Query<&InheritedVisibility>) {
     for inherited_visibility in &q {
         if inherited_visibility.get() {
 ```
 
 ```rust
 // Before:
 fn my_system(q: Query<&ComputedVisibilty>) {
     for vis in &q {
         if vis.is_visible_in_view() {
     
 // After:
 fn my_system(q: Query<&ViewVisibility>) {
     for view_visibility in &q {
         if view_visibility.get() {
 ```
 
 ```rust
 // Before:
 fn my_system(mut q: Query<&mut ComputedVisibilty>) {
     for vis in &mut q {
         vis.set_visible_in_view();
     
 // After:
 fn my_system(mut q: Query<&mut ViewVisibility>) {
     for view_visibility in &mut q {
         view_visibility.set();
 ```

---------

Co-authored-by: Robert Swain <robert.swain@gmail.com>
2023-09-01 13:00:18 +00:00
James O'Brien
4f1d9a6315
Reorder render sets, refactor bevy_sprite to take advantage (#9236)
This is a continuation of this PR: #8062 

# Objective

- Reorder render schedule sets to allow data preparation when phase item
order is known to support improved batching
- Part of the batching/instancing etc plan from here:
https://github.com/bevyengine/bevy/issues/89#issuecomment-1379249074
- The original idea came from @inodentry and proved to be a good one.
Thanks!
- Refactor `bevy_sprite` and `bevy_ui` to take advantage of the new
ordering

## Solution
- Move `Prepare` and `PrepareFlush` after `PhaseSortFlush` 
- Add a `PrepareAssets` set that runs in parallel with other systems and
sets in the render schedule.
  - Put prepare_assets systems in the `PrepareAssets` set
- If explicit dependencies are needed on Mesh or Material RenderAssets
then depend on the appropriate system.
- Add `ManageViews` and `ManageViewsFlush` sets between
`ExtractCommands` and Queue
- Move `queue_mesh*_bind_group` to the Prepare stage
  - Rename them to `prepare_`
- Put systems that prepare resources (buffers, textures, etc.) into a
`PrepareResources` set inside `Prepare`
- Put the `prepare_..._bind_group` systems into a `PrepareBindGroup` set
after `PrepareResources`
- Move `prepare_lights` to the `ManageViews` set
  - `prepare_lights` creates views and this must happen before `Queue`
  - This system needs refactoring to stop handling all responsibilities
- Gather lights, sort, and create shadow map views. Store sorted light
entities in a resource

- Remove `BatchedPhaseItem`
- Replace `batch_range` with `batch_size` representing how many items to
skip after rendering the item or to skip the item entirely if
`batch_size` is 0.
- `queue_sprites` has been split into `queue_sprites` for queueing phase
items and `prepare_sprites` for batching after the `PhaseSort`
  - `PhaseItem`s are still inserted in `queue_sprites`
- After sorting adjacent compatible sprite phase items are accumulated
into `SpriteBatch` components on the first entity of each batch,
containing a range of vertex indices. The associated `PhaseItem`'s
`batch_size` is updated appropriately.
- `SpriteBatch` items are then drawn skipping over the other items in
the batch based on the value in `batch_size`
- A very similar refactor was performed on `bevy_ui`
---

## Changelog

Changed:
- Reordered and reworked render app schedule sets. The main change is
that data is extracted, queued, sorted, and then prepared when the order
of data is known.
- Refactor `bevy_sprite` and `bevy_ui` to take advantage of the
reordering.

## Migration Guide
- Assets such as materials and meshes should now be created in
`PrepareAssets` e.g. `prepare_assets<Mesh>`
- Queueing entities to `RenderPhase`s continues to be done in `Queue`
e.g. `queue_sprites`
- Preparing resources (textures, buffers, etc.) should now be done in
`PrepareResources`, e.g. `prepare_prepass_textures`,
`prepare_mesh_uniforms`
- Prepare bind groups should now be done in `PrepareBindGroups` e.g.
`prepare_mesh_bind_group`
- Any batching or instancing can now be done in `Prepare` where the
order of the phase items is known e.g. `prepare_sprites`

 
## Next Steps
- Introduce some generic mechanism to ensure items that can be batched
are grouped in the phase item order, currently you could easily have
`[sprite at z 0, mesh at z 0, sprite at z 0]` preventing batching.
 - Investigate improved orderings for building the MeshUniform buffer
 - Implementing batching across the rest of bevy

---------

Co-authored-by: Robert Swain <robert.swain@gmail.com>
Co-authored-by: robtfm <50659922+robtfm@users.noreply.github.com>
2023-08-27 14:33:49 +00:00
robtfm
10f5c92068
improve shader import model (#5703)
# Objective

operate on naga IR directly to improve handling of shader modules.
- give codespan reporting into imported modules
- allow glsl to be used from wgsl and vice-versa

the ultimate objective is to make it possible to 
- provide user hooks for core shader functions (to modify light
behaviour within the standard pbr pipeline, for example)
- make automatic binding slot allocation possible

but ... since this is already big, adds some value and (i think) is at
feature parity with the existing code, i wanted to push this now.

## Solution

i made a crate called naga_oil (https://github.com/robtfm/naga_oil -
unpublished for now, could be part of bevy) which manages modules by
- building each module independantly to naga IR
- creating "header" files for each supported language, which are used to
build dependent modules/shaders
- make final shaders by combining the shader IR with the IR for imported
modules

then integrated this into bevy, replacing some of the existing shader
processing stuff. also reworked examples to reflect this.

## Migration Guide

shaders that don't use `#import` directives should work without changes.

the most notable user-facing difference is that imported
functions/variables/etc need to be qualified at point of use, and
there's no "leakage" of visible stuff into your shader scope from the
imports of your imports, so if you used things imported by your imports,
you now need to import them directly and qualify them.

the current strategy of including/'spreading' `mesh_vertex_output`
directly into a struct doesn't work any more, so these need to be
modified as per the examples (e.g. color_material.wgsl, or many others).
mesh data is assumed to be in bindgroup 2 by default, if mesh data is
bound into bindgroup 1 instead then the shader def `MESH_BINDGROUP_1`
needs to be added to the pipeline shader_defs.
2023-06-27 00:29:22 +00:00
Edgar Geier
f18f28874a
Allow tuples and single plugins in add_plugins, deprecate add_plugin (#8097)
# Objective

- Better consistency with `add_systems`.
- Deprecating `add_plugin` in favor of a more powerful `add_plugins`.
- Allow passing `Plugin` to `add_plugins`.
- Allow passing tuples to `add_plugins`.

## Solution

- `App::add_plugins` now takes an `impl Plugins` parameter.
- `App::add_plugin` is deprecated.
- `Plugins` is a new sealed trait that is only implemented for `Plugin`,
`PluginGroup` and tuples over `Plugins`.
- All examples, benchmarks and tests are changed to use `add_plugins`,
using tuples where appropriate.

---

## Changelog

### Changed

- `App::add_plugins` now accepts all types that implement `Plugins`,
which is implemented for:
  - Types that implement `Plugin`.
  - Types that implement `PluginGroup`.
  - Tuples (up to 16 elements) over types that implement `Plugins`.
- Deprecated `App::add_plugin` in favor of `App::add_plugins`.

## Migration Guide

- Replace `app.add_plugin(plugin)` calls with `app.add_plugins(plugin)`.

---------

Co-authored-by: Carter Anderson <mcanders1@gmail.com>
2023-06-21 20:51:03 +00:00
Jakob Hellermann
1ff4b98755
fix new clippy lints before they reach stable (#8700)
# Objective

- fix clippy lints early to make sure CI doesn't break when they get
promoted to stable
- have a noise-free `clippy` experience for nightly users

## Solution

- `cargo clippy --fix`
- replace `filter_map(|x| x.ok())` with `map_while(|x| x.ok())` to fix
potential infinite loop in case of IO error
2023-05-29 07:23:50 +00:00
François
e0b18091b5
fix missed examples in WebGPU update (#8553)
# Objective

- I missed a few examples in #8336 
- fixes #8556 
- fixes #8620

## Solution

- Update them
2023-05-16 20:31:30 +00:00
Carter Anderson
aefe1f0739
Schedule-First: the new and improved add_systems (#8079)
Co-authored-by: Mike <mike.hsu@gmail.com>
2023-03-18 01:45:34 +00:00
JoJoJet
fd1af7c8b8
Replace multiple calls to add_system with add_systems (#8001) 2023-03-10 18:15:22 +00:00
JoJoJet
b8263b55fb Support system.in_schedule() and system.on_startup() (#7790)
# Objective

Support the following syntax for adding systems:

```rust
App::new()
    .add_system(setup.on_startup())
    .add_systems((
        show_menu.in_schedule(OnEnter(GameState::Paused)),
        menu_ssytem.in_set(OnUpdate(GameState::Paused)),
        hide_menu.in_schedule(OnExit(GameState::Paused)),
    ))
```

## Solution

Add the traits `IntoSystemAppConfig{s}`, which provide the extension methods necessary for configuring which schedule a system belongs to. These extension methods return `IntoSystemAppConfig{s}`, which `App::add_system{s}` uses to choose which schedule to add systems to.

---

## Changelog

+ Added the extension methods `in_schedule(label)` and  `on_startup()` for configuring the schedule a system belongs to.

## Future Work

* Replace all uses of `add_startup_system` in the engine.
* Deprecate this method
2023-02-24 18:33:55 +00:00
Zhixing Zhang
16feb9acb7 Add push contant config to layout (#7681)
# Objective

Allow for creating pipelines that use push constants. To be able to use push constants. Fixes #4825

As of right now, trying to call `RenderPass::set_push_constants` will trigger the following error:

```
thread 'main' panicked at 'wgpu error: Validation Error

Caused by:
    In a RenderPass
      note: encoder = `<CommandBuffer-(0, 59, Vulkan)>`
    In a set_push_constant command
    provided push constant is for stage(s) VERTEX | FRAGMENT | VERTEX_FRAGMENT, however the pipeline layout has no push constant range for the stage(s) VERTEX | FRAGMENT | VERTEX_FRAGMENT
```
## Solution

Add a field push_constant_ranges to` RenderPipelineDescriptor` and `ComputePipelineDescriptor`.

This PR supersedes #4908 which now contains merge conflicts due to significant changes to `bevy_render`.

Meanwhile, this PR also made the `layout` field of `RenderPipelineDescriptor` and `ComputePipelineDescriptor` non-optional. If the user do not need to specify the bind group layouts, they can simply supply an empty vector here. No need for it to be optional.

---

## Changelog
- Add a field push_constant_ranges to RenderPipelineDescriptor and ComputePipelineDescriptor
- Made the `layout` field of RenderPipelineDescriptor and ComputePipelineDescriptor non-optional.


## Migration Guide

- Add push_constant_ranges: Vec::new() to every `RenderPipelineDescriptor` and `ComputePipelineDescriptor`
- Unwrap the optional values on the `layout` field of `RenderPipelineDescriptor` and `ComputePipelineDescriptor`. If the descriptor has no layout, supply an empty vector.


Co-authored-by: Zhixing Zhang <me@neoto.xin>
2023-02-17 06:20:16 +00:00