Commit graph

257 commits

Author SHA1 Message Date
Patrick Walton
f9cc91d5a1
Intern mesh vertex buffer layouts so that we don't have to compare them over and over. (#12216)
Although we cached hashes of `MeshVertexBufferLayout`, we were paying
the cost of `PartialEq` on `InnerMeshVertexBufferLayout` for every
entity, every frame. This patch changes that logic to place
`MeshVertexBufferLayout`s in `Arc`s so that they can be compared and
hashed by pointer. This results in a 28% speedup in the
`queue_material_meshes` phase of `many_cubes`, with frustum culling
disabled.

Additionally, this patch contains two minor changes:

1. This commit flattens the specialized mesh pipeline cache to one level
of hash tables instead of two. This saves a hash lookup.

2. The example `many_cubes` has been given a `--no-frustum-culling`
flag, to aid in benchmarking.

See the Tracy profile:

<img width="1064" alt="Screenshot 2024-02-29 144406"
src="https://github.com/bevyengine/bevy/assets/157897/18632f1d-1fdd-4ac7-90ed-2d10306b2a1e">

## Migration guide

* Duplicate `MeshVertexBufferLayout`s are now combined into a single
object, `MeshVertexBufferLayoutRef`, which contains an
atomically-reference-counted pointer to the layout. Code that was using
`MeshVertexBufferLayout` may need to be updated to use
`MeshVertexBufferLayoutRef` instead.
2024-03-01 20:56:21 +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
Joona Aalto
f418de8eb6
Rename Direction2d/3d to Dir2/3 (#12189)
# Objective

Split up from #12017, rename Bevy's direction types.

Currently, Bevy has the `Direction2d`, `Direction3d`, and `Direction3dA`
types, which provide a type-level guarantee that their contained vectors
remain normalized. They can be very useful for a lot of APIs for safety,
explicitness, and in some cases performance, as they can sometimes avoid
unnecessary normalizations.

However, many consider them to be inconvenient to use, and opt for
standard vector types like `Vec3` because of this. One reason is that
the direction type names are a bit long and can be annoying to write (of
course you can use autocomplete, but just typing `Vec3` is still nicer),
and in some intances, the extra characters can make formatting worse.
The naming is also inconsistent with Glam's shorter type names, and
results in names like `Direction3dA`, which (in my opinion) are
difficult to read and even a bit ugly.

This PR proposes renaming the types to `Dir2`, `Dir3`, and `Dir3A`.
These names are nice and easy to write, consistent with Glam, and work
well for variants like the SIMD aligned `Dir3A`. As a bonus, it can also
result in nicer formatting in a lot of cases, which can be seen from the
diff of this PR.

Some examples of what it looks like: (copied from #12017)

```rust
// Before
let ray_cast = RayCast2d::new(Vec2::ZERO, Direction2d::X, 5.0);

// After
let ray_cast = RayCast2d::new(Vec2::ZERO, Dir2::X, 5.0);
```

```rust
// Before (an example using Bevy XPBD)
let hit = spatial_query.cast_ray(
    Vec3::ZERO,
    Direction3d::X,
    f32::MAX,
    true,
    SpatialQueryFilter::default(),
);

// After
let hit = spatial_query.cast_ray(
    Vec3::ZERO,
    Dir3::X,
    f32::MAX,
    true,
    SpatialQueryFilter::default(),
);
```

```rust
// Before
self.circle(
    Vec3::new(0.0, -2.0, 0.0),
    Direction3d::Y,
    5.0,
    Color::TURQUOISE,
);

// After (formatting is collapsed in this case)
self.circle(Vec3::new(0.0, -2.0, 0.0), Dir3::Y, 5.0, Color::TURQUOISE);
```

## Solution

Rename `Direction2d`, `Direction3d`, and `Direction3dA` to `Dir2`,
`Dir3`, and `Dir3A`.

---

## Migration Guide

The `Direction2d` and `Direction3d` types have been renamed to `Dir2`
and `Dir3`.

## Additional Context

This has been brought up on the Discord a few times, and we had a small
[poll](https://discord.com/channels/691052431525675048/1203087353850364004/1212465038711984158)
on this. `Dir2`/`Dir3`/`Dir3A` was quite unanimously chosen as the best
option, but of course it was a very small poll and inconclusive, so
other opinions are certainly welcome too.

---------

Co-authored-by: IceSentry <c.giguere42@gmail.com>
2024-02-28 22:48:43 +00:00
Alex
a7be8a2655
Prefer UVec2 when working with texture dimensions (#11698)
# Objective

The physical width and height (pixels) of an image is always integers,
but for `GpuImage` bevy currently stores them as `Vec2` (`f32`).
Switching to `UVec2` makes this more consistent with the [underlying
texture data](https://docs.rs/wgpu/latest/wgpu/struct.Extent3d.html).

I'm not sure if this is worth the change in the surface level API. If
not, feel free to close this PR.

## Solution

- Replace uses of `Vec2` with `UVec2` when referring to texture
dimensions.
- Use integer types for the texture atlas dimensions and sections.


[`Sprite::rect`](a81a2d1da3/crates/bevy_sprite/src/sprite.rs (L29))
remains unchanged, so manually specifying a sub-pixel region of an image
is still possible.

---

## Changelog

- `GpuImage` now stores its size as `UVec2` instead of `Vec2`.
- Texture atlases store their size and sections as `UVec2` and `URect`
respectively.
- `UiImageSize` stores its size as `UVec2`.

## Migration Guide

- Change floating point types (`Vec2`, `Rect`) to their respective
unsigned integer versions (`UVec2`, `URect`) when using `GpuImage`,
`TextureAtlasLayout`, `TextureAtlasBuilder`,
`DynamicAtlasTextureBuilder` or `FontAtlas`.
2024-02-25 15:23:04 +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
Evgeny Kropotin
d3e839a8e5
Move gizmos examples in the separate folder (#11916)
# Objective

Move Gizmo examples into the separate directory

Fixes #11899

---------

Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: Joona Aalto <jondolf.dev@gmail.com>
2024-02-21 20:16:25 +00:00
Andrew
24e8e67b91
text2d example: animate_scale no longer unnecessarily performs the same translation at each Update (#11936)
# Objective

- The `transform.translation` of a `TextBundle` in this example is
unnecessarily set to the same constant position over and over in each
`Update`. Newbies might be confused as to why this translation is being
performed over and over.

## Solution

- perform the translation only once, when the `Text2dBundle` is
instantiated
2024-02-19 00:38:49 +00:00
Rob Parrett
1d5388eded
Un-hardcode positions and colors in 2d_shapes example (#11867)
# Objective

We recently got some neat new 2d shapes and the shapes are no longer
centered on the screen.

The hardcoded positions and colors are a pain to deal with when a new
shape is added.

## Solution

Delete a bunch of code and position shapes evenly. Assign colors evenly
too.

## Before

<img width="1280" alt="Screenshot 2024-02-14 at 3 17 40 PM"
src="https://github.com/bevyengine/bevy/assets/200550/cc9fd9a8-4019-4907-a50e-621cb656c20a">

## After

<img width="1280" alt="Screenshot 2024-02-14 at 3 17 24 PM"
src="https://github.com/bevyengine/bevy/assets/200550/033a3f91-d3bc-4ec8-af59-42a221f8b8e7">

---------

Co-authored-by: BD103 <59022059+BD103@users.noreply.github.com>
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: Joona Aalto <jondolf.dev@gmail.com>
2024-02-14 23:36:18 +00:00
Robert Walter
b446374392
Dedicated primitive example (#11697)
I just implemented this to record a video for the new blog post, but I
figured it would also make a good dedicated example. This also allows us
to remove a lot of code from the 2d/3d gizmo examples since it
supersedes this portion of code.

Depends on: https://github.com/bevyengine/bevy/pull/11699
2024-02-14 16:55:44 +00:00
Niklas Eicker
aca71d09b1
Call a TextureAtlasLayout a layout and not an atlas (#11783)
Make the renamings/changes regarding texture atlases a bit less
confusing by calling `TextureAtlasLayout` a layout, not a texture atlas.

Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
2024-02-13 16:08:03 +00:00
Félix Lescaudey de Maneville
e0c296ee14
Optional ImageScaleMode (#11780)
> Follow up to #11600 and #10588 

@mockersf expressed some [valid
concerns](https://github.com/bevyengine/bevy/pull/11600#issuecomment-1932796498)
about the current system this PR attempts to fix:

The `ComputedTextureSlices` reacts to asset change in both `bevy_sprite`
and `bevy_ui`, meaning that if the `ImageScaleMode` is inserted by
default in the bundles, we will iterate through most 2d items every time
an asset is updated.

# Solution

- `ImageScaleMode` only has two variants: `Sliced` and `Tiled`. I
removed the `Stretched` default
- `ImageScaleMode` is no longer part of any bundle, but the relevant
bundles explain that this additional component can be inserted

This way, the *absence* of `ImageScaleMode` means the image will be
stretched, and its *presence* will include the entity to the various
slicing systems

Optional components in bundles would make this more straigthfoward

# Additional work

Should I add new bundles with the `ImageScaleMode` component ?
2024-02-09 20:36:32 +00:00
Joona Aalto
0166db33f7
Deprecate shapes in bevy_render::mesh::shape (#11773)
# Objective

#11431 and #11688 implemented meshing support for Bevy's new geometric
primitives. The next step is to deprecate the shapes in
`bevy_render::mesh::shape` and to later remove them completely for 0.14.

## Solution

Deprecate the shapes and reduce code duplication by utilizing the
primitive meshing API for the old shapes where possible.

Note that some shapes have behavior that can't be exactly reproduced
with the new primitives yet:

- `Box` is more of an AABB with min/max extents
- `Plane` supports a subdivision count
- `Quad` has a `flipped` property

These types have not been changed to utilize the new primitives yet.

---

## Changelog

- Deprecated all shapes in `bevy_render::mesh::shape`
- Changed all examples to use new primitives for meshing

## Migration Guide

Bevy has previously used rendering-specific types like `UVSphere` and
`Quad` for primitive mesh shapes. These have now been deprecated to use
the geometric primitives newly introduced in version 0.13.

Some examples:

```rust
let before = meshes.add(shape::Box::new(5.0, 0.15, 5.0));
let after = meshes.add(Cuboid::new(5.0, 0.15, 5.0));

let before = meshes.add(shape::Quad::default());
let after = meshes.add(Rectangle::default());

let before = meshes.add(shape::Plane::from_size(5.0));
// The surface normal can now also be specified when using `new`
let after = meshes.add(Plane3d::default().mesh().size(5.0, 5.0));

let before = meshes.add(
    Mesh::try_from(shape::Icosphere {
        radius: 0.5,
        subdivisions: 5,
    })
    .unwrap(),
);
let after = meshes.add(Sphere::new(0.5).mesh().ico(5).unwrap());
```
2024-02-08 18:01:34 +00:00
Félix Lescaudey de Maneville
ab16f5ed6a
UI Texture 9 slice (#11600)
> Follow up to #10588 
> Closes #11749 (Supersedes #11756)

Enable Texture slicing for the following UI nodes:
- `ImageBundle`
- `ButtonBundle`

<img width="739" alt="Screenshot 2024-01-29 at 13 57 43"
src="https://github.com/bevyengine/bevy/assets/26703856/37675681-74eb-4689-ab42-024310cf3134">

I also added a collection of `fantazy-ui-borders` from
[Kenney's](www.kenney.nl) assets, with the appropriate license (CC).
If it's a problem I can use the same textures as the `sprite_slice`
example

# Work done

Added the `ImageScaleMode` component to the targetted bundles, most of
the logic is directly reused from `bevy_sprite`.
The only additional internal component is the UI specific
`ComputedSlices`, which does the same thing as its spritee equivalent
but adapted to UI code.

Again the slicing is not compatible with `TextureAtlas`, it's something
I need to tackle more deeply in the future

# Fixes

* [x] I noticed that `TextureSlicer::compute_slices` could infinitely
loop if the border was larger that the image half extents, now an error
is triggered and the texture will fallback to being stretched
* [x] I noticed that when using small textures with very small *tiling*
options we could generate hundred of thousands of slices. Now I set a
minimum size of 1 pixel per slice, which is already ridiculously small,
and a warning will be sent at runtime when slice count goes above 1000
* [x] Sprite slicing with `flip_x` or `flip_y` would give incorrect
results, correct flipping is now supported to both sprites and ui image
nodes thanks to @odecay observation

# GPU Alternative

I create a separate branch attempting to implementing 9 slicing and
tiling directly through the `ui.wgsl` fragment shader. It works but
requires sending more data to the GPU:
- slice border
- tiling factors

And more importantly, the actual quad *scale* which is hard to put in
the shader with the current code, so that would be for a later iteration
2024-02-07 20:07:53 +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
Joona Aalto
9bad607df9
Implement meshing for Capsule2d (#11639)
# Objective

The `Capsule2d` primitive was added in #11585. It should support meshing
like the other 2D primitives.

## Solution

Implement meshing for `Capsule2d`.

It doesn't currently support "rings" like Bevy's `Capsule` shape (not
`Capsule3d`), but it does support resolution to control the number of
vertices used for one hemicircle. The total vertex count is two times
the resolution; if we allowed setting the full vertex count, odd numbers
would lead to uneven vertex counts for the top and bottom hemicircles
and produce potentially unwanted results.

The capsule looks like this (with UV visualization and wireframe) using
resolutions of 16, 8, and 3:

![Resolution
16](https://github.com/bevyengine/bevy/assets/57632562/feae22de-bdc5-438a-861f-848284b67a52)
![Resolution
8](https://github.com/bevyengine/bevy/assets/57632562/e95aab8e-793f-45ac-8a74-8be39f7626dd)
![Resolution of
3](https://github.com/bevyengine/bevy/assets/57632562/bcf01d23-1d8b-4cdb-966a-c9022a07c287)

The `2d_shapes` example now includes the capsule, so we also get one
more color of the rainbow 🌈

![New 2D shapes
example](https://github.com/bevyengine/bevy/assets/57632562/1c45b5f5-d26a-4e8c-8e8a-e106ab14d46e)
2024-02-03 18:03:43 +00:00
NiseVoid
ab9447ac32
Add example for bounding volumes and intersection tests (#11666)
# Objective

- Create an example for bounding volumes and intersection tests

## Solution

- Add an example with a few bounding volumes, created from primitives
- Allow the user to cycle trough the different intersection tests
2024-02-03 17:11:01 +00:00
Robert Walter
041731b7e0
Drawing Primitives with Gizmos (#11072)
The PR is in a reviewable state now in the sense that the basic
implementations are there. There are still some ToDos that I'm aware of:

- [x] docs for all the new structs and traits
- [x] implement `Default` and derive other useful traits for the new
structs
- [x] Take a look at the notes again (Do this after a first round of
reviews)
- [x] Take care of the repetition in the circle drawing functions

---

# Objective

- TLDR: This PR enables us to quickly draw all the newly added
primitives from `bevy_math` in immediate mode with gizmos
- Addresses #10571

## Solution

- This implements the first design idea I had that covered everything
that was mentioned in the Issue
https://github.com/bevyengine/bevy/issues/10571#issuecomment-1863646197

--- 

## Caveats

- I added the `Primitive(2/3)d` impls for `Direction(2/3)d` to make them
work with the current solution. We could impose less strict requirements
for the gizmoable objects and remove the impls afterwards if the
community doesn't like the current approach.

---

## Changelog

- implement capabilities to draw ellipses on the gizmo in general (this
was required to have some code which is able to draw the ellipse
primitive)
- refactored circle drawing code to use the more general ellipse drawing
code to keep code duplication low
- implement `Primitive2d` for `Direction2d` and impl `Primitive3d` for
`Direction3d`
- implement trait to draw primitives with specialized details with
gizmos
  - `GizmoPrimitive2d` for all the 2D primitives
  - `GizmoPrimitive3d` for all the 3D primitives
- (question while writing this: Does it actually matter if we split this
in 2D and 3D? I guess it could be useful in the future if we do
something based on the main rendering mode even though atm it's kinda
useless)

---

---------

Co-authored-by: nothendev <borodinov.ilya@gmail.com>
2024-02-02 21:13:03 +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
Joona Aalto
2bf481c03b
Add Meshable trait and implement meshing for 2D primitives (#11431)
# Objective

The first part of #10569, split up from #11007.

The goal is to implement meshing support for Bevy's new geometric
primitives, starting with 2D primitives. 3D meshing will be added in a
follow-up, and we can consider removing the old mesh shapes completely.

## Solution

Add a `Meshable` trait that primitives need to implement to support
meshing, as suggested by the
[RFC](https://github.com/bevyengine/rfcs/blob/main/rfcs/12-primitive-shapes.md#meshing).

```rust
/// A trait for shapes that can be turned into a [`Mesh`].
pub trait Meshable {
    /// The output of [`Self::mesh`]. This can either be a [`Mesh`]
    /// or a builder used for creating a [`Mesh`].
    type Output;

    /// Creates a [`Mesh`] for a shape.
    fn mesh(&self) -> Self::Output;
}
```

This PR implements it for the following primitives:

- `Circle`
- `Ellipse`
- `Rectangle`
- `RegularPolygon`
- `Triangle2d`

The `mesh` method typically returns a builder-like struct such as
`CircleMeshBuilder`. This is needed to support shape-specific
configuration for things like mesh resolution or UV configuration:

```rust
meshes.add(Circle { radius: 0.5 }.mesh().resolution(64));
```

Note that if no configuration is needed, you can even skip calling
`mesh` because `From<MyPrimitive>` is implemented for `Mesh`:

```rust
meshes.add(Circle { radius: 0.5 });
```

I also updated the `2d_shapes` example to use primitives, and tweaked
the colors to have better contrast against the dark background.

Before:

![Old 2D
shapes](https://github.com/bevyengine/bevy/assets/57632562/f1d8c2d5-55be-495f-8ed4-5890154b81ca)

After:

![New 2D
shapes](https://github.com/bevyengine/bevy/assets/57632562/f166c013-34b8-4752-800a-5517b284d978)

Here you can see the UVs and different facing directions: (taken from
#11007, so excuse the 3D primitives at the bottom left)

![UVs and facing
directions](https://github.com/bevyengine/bevy/assets/57632562/eaf0be4e-187d-4b6d-8fb8-c996ba295a8a)

---

## Changelog

- Added `bevy_render::mesh::primitives` module
- Added `Meshable` trait and implemented it for:
  - `Circle`
  - `Ellipse`
  - `Rectangle`
  - `RegularPolygon`
  - `Triangle2d`
- Implemented `Default` and `Copy` for several 2D primitives
- Updated `2d_shapes` example to use primitives
- Tweaked colors in `2d_shapes` example to have better contrast against
the (new-ish) dark background

---------

Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
2024-01-29 16:47:47 +00:00
Bude
3851679173
Allow TextureAtlasBuilder in AssetLoader (#11548)
# Objective

Allow TextureAtlasBuilder in AssetLoader.
Fixes #2987

## Solution

- TextureAtlasBuilder no longer hold just AssetIds that are used to
retrieve the actual image data in `finish`, but &Image instead.
- TextureAtlasBuilder now required AssetId only optionally (and it is
only used to retrieve the index from the AssetId in TextureAtlasLayout),

## Issues

- The issue mentioned here
https://github.com/bevyengine/bevy/pull/11474#issuecomment-1904676937
now also extends to the actual atlas texture. In short: Calling
add_texture multiple times for the same texture will lead to duplicate
image data in the atlas texture and additional indices.
If you provide an AssetId we can probably do something to de-duplicate
the entries while keeping insertion order (suggestions welcome on how
exactly). But if you don't then we are out of luck (unless we can and
want to hash the image, which I do not think we want).

---

## Changelog

### Changed
- TextureAtlasBuilder `add_texture` can be called without providing an
AssetId
- TextureAtlasBuilder `finish` no longer takes Assets<Image> and no
longer returns a Handle<Image>

## Migration Guide

- For `add_texture` you need to wrap your AssetId in Some
- `finish` now returns the atlas texture image directly instead of a
handle. Provide the atlas texture to `add` on Assets<Texture> to get a
Handle<Image>
2024-01-27 16:16:44 +00:00
jeliag
f6b40a6e43
Multiple Configurations for Gizmos (#10342)
# Objective

This PR aims to implement multiple configs for gizmos as discussed in
#9187.

## Solution

Configs for the new `GizmoConfigGroup`s are stored in a
`GizmoConfigStore` resource and can be accesses using a type based key
or iterated over. This type based key doubles as a standardized location
where plugin authors can put their own configuration not covered by the
standard `GizmoConfig` struct. For example the `AabbGizmoGroup` has a
default color and toggle to show all AABBs. New configs can be
registered using `app.init_gizmo_group::<T>()` during startup.

When requesting the `Gizmos<T>` system parameter the generic type
determines which config is used. The config structs are available
through the `Gizmos` system parameter allowing for easy access while
drawing your gizmos.

Internally, resources and systems used for rendering (up to an including
the extract system) are generic over the type based key and inserted on
registering a new config.

## Alternatives

The configs could be stored as components on entities with markers which
would make better use of the ECS. I also implemented this approach
([here](https://github.com/jeliag/bevy/tree/gizmo-multiconf-comp)) and
believe that the ergonomic benefits of a central config store outweigh
the decreased use of the ECS.

## Unsafe Code

Implementing system parameter by hand is unsafe but seems to be required
to access the config store once and not on every gizmo draw function
call. This is critical for performance. ~Is there a better way to do
this?~

## Future Work

New gizmos (such as #10038, and ideas from #9400) will require custom
configuration structs. Should there be a new custom config for every
gizmo type, or should we group them together in a common configuration?
(for example `EditorGizmoConfig`, or something more fine-grained)

## Changelog

- Added `GizmoConfigStore` resource and `GizmoConfigGroup` trait
- Added `init_gizmo_group` to `App`
- Added early returns to gizmo drawing increasing performance when
gizmos are disabled
- Changed `GizmoConfig` and aabb gizmos to use new `GizmoConfigStore`
- Changed `Gizmos` system parameter to use type based key to retrieve
config
- Changed resources and systems used for gizmo rendering to be generic
over type based key
- Changed examples (3d_gizmos, 2d_gizmos) to showcase new API

## Migration Guide

- `GizmoConfig` is no longer a resource and has to be accessed through
`GizmoConfigStore` resource. The default config group is
`DefaultGizmoGroup`, but consider using your own custom config group if
applicable.

---------

Co-authored-by: Nicola Papale <nicopap@users.noreply.github.com>
2024-01-18 15:52:50 +00:00
Félix Lescaudey de Maneville
135c7240f1
Texture Atlas rework (#5103)
# Objective

> Old MR: #5072 
> ~~Associated UI MR: #5070~~
> Adresses #1618

Unify sprite management

## Solution

- Remove the `Handle<Image>` field in `TextureAtlas` which is the main
cause for all the boilerplate
- Remove the redundant `TextureAtlasSprite` component
- Renamed `TextureAtlas` asset to `TextureAtlasLayout`
([suggestion](https://github.com/bevyengine/bevy/pull/5103#discussion_r917281844))
- Add a `TextureAtlas` component, containing the atlas layout handle and
the section index

The difference between this solution and #5072 is that instead of the
`enum` approach is that we can more easily manipulate texture sheets
without any breaking changes for classic `SpriteBundle`s (@mockersf
[comment](https://github.com/bevyengine/bevy/pull/5072#issuecomment-1165836139))

Also, this approach is more *data oriented* extracting the
`Handle<Image>` and avoiding complex texture atlas manipulations to
retrieve the texture in both applicative and engine code.
With this method, the only difference between a `SpriteBundle` and a
`SpriteSheetBundle` is an **additional** component storing the atlas
handle and the index.

~~This solution can be applied to `bevy_ui` as well (see #5070).~~

EDIT: I also applied this solution to Bevy UI

## Changelog

- (**BREAKING**) Removed `TextureAtlasSprite`
- (**BREAKING**) Renamed `TextureAtlas` to `TextureAtlasLayout`
- (**BREAKING**) `SpriteSheetBundle`:
  - Uses a  `Sprite` instead of a `TextureAtlasSprite` component
- Has a `texture` field containing a `Handle<Image>` like the
`SpriteBundle`
- Has a new `TextureAtlas` component instead of a
`Handle<TextureAtlasLayout>`
- (**BREAKING**) `DynamicTextureAtlasBuilder::add_texture` takes an
additional `&Handle<Image>` parameter
- (**BREAKING**) `TextureAtlasLayout::from_grid` no longer takes a
`Handle<Image>` parameter
- (**BREAKING**) `TextureAtlasBuilder::finish` now returns a
`Result<(TextureAtlasLayout, Handle<Image>), _>`
- `bevy_text`:
  - `GlyphAtlasInfo` stores the texture `Handle<Image>`
  - `FontAtlas` stores the texture `Handle<Image>`
- `bevy_ui`:
- (**BREAKING**) Removed `UiAtlasImage` , the atlas bundle is now
identical to the `ImageBundle` with an additional `TextureAtlas`

## Migration Guide

* Sprites

```diff
fn my_system(
  mut images: ResMut<Assets<Image>>, 
-  mut atlases: ResMut<Assets<TextureAtlas>>, 
+  mut atlases: ResMut<Assets<TextureAtlasLayout>>, 
  asset_server: Res<AssetServer>
) {
    let texture_handle: asset_server.load("my_texture.png");
-   let layout = TextureAtlas::from_grid(texture_handle, Vec2::new(25.0, 25.0), 5, 5, None, None);
+   let layout = TextureAtlasLayout::from_grid(Vec2::new(25.0, 25.0), 5, 5, None, None);
    let layout_handle = atlases.add(layout);
    commands.spawn(SpriteSheetBundle {
-      sprite: TextureAtlasSprite::new(0),
-      texture_atlas: atlas_handle,
+      atlas: TextureAtlas {
+         layout: layout_handle,
+         index: 0
+      },
+      texture: texture_handle,
       ..Default::default()
     });
}
```
* UI


```diff
fn my_system(
  mut images: ResMut<Assets<Image>>, 
-  mut atlases: ResMut<Assets<TextureAtlas>>, 
+  mut atlases: ResMut<Assets<TextureAtlasLayout>>, 
  asset_server: Res<AssetServer>
) {
    let texture_handle: asset_server.load("my_texture.png");
-   let layout = TextureAtlas::from_grid(texture_handle, Vec2::new(25.0, 25.0), 5, 5, None, None);
+   let layout = TextureAtlasLayout::from_grid(Vec2::new(25.0, 25.0), 5, 5, None, None);
    let layout_handle = atlases.add(layout);
    commands.spawn(AtlasImageBundle {
-      texture_atlas_image: UiTextureAtlasImage {
-           index: 0,
-           flip_x: false,
-           flip_y: false,
-       },
-      texture_atlas: atlas_handle,
+      atlas: TextureAtlas {
+         layout: layout_handle,
+         index: 0
+      },
+      image: UiImage {
+           texture: texture_handle,
+           flip_x: false,
+           flip_y: false,
+       },
       ..Default::default()
     });
}
```

---------

Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: François <mockersf@gmail.com>
Co-authored-by: IceSentry <IceSentry@users.noreply.github.com>
2024-01-16 13:59:08 +00:00
Félix Lescaudey de Maneville
01139b3472
Sprite slicing and tiling (#10588)
> Replaces #5213

# Objective

Implement sprite tiling and [9 slice
scaling](https://en.wikipedia.org/wiki/9-slice_scaling) for
`bevy_sprite`.
Allowing slice scaling and texture tiling.

Basic scaling vs 9 slice scaling:


![Traditional_scaling_vs_9-slice_scaling](https://user-images.githubusercontent.com/26703856/177335801-27f6fa27-c569-4ce6-b0e6-4f54e8f4e80a.svg)

Slicing example:

<img width="481" alt="Screenshot 2022-07-05 at 15 05 49"
src="https://user-images.githubusercontent.com/26703856/177336112-9e961af0-c0af-4197-aec9-430c1170a79d.png">

Tiling example:

<img width="1329" alt="Screenshot 2023-11-16 at 13 53 32"
src="https://github.com/bevyengine/bevy/assets/26703856/14db39b7-d9e0-4bc3-ba0e-b1f2db39ae8f">

# Solution

- `SpriteBundlue` now has a `scale_mode` component storing a
`SpriteScaleMode` enum with three variants:
  - `Stretched` (default) 
  - `Tiled` to have sprites tile horizontally and/or vertically
- `Sliced` allowing 9 slicing the texture and optionally tile some
sections with a `Textureslicer`.
- `bevy_sprite` has two extra systems to compute a
`ComputedTextureSlices` if necessary,:
- One system react to changes on `Sprite`, `Handle<Image>` or
`SpriteScaleMode`
- The other listens to `AssetEvent<Image>` to compute slices on sprites
when the texture is ready or changed
- I updated the `bevy_sprite` extraction stage to extract potentially
multiple textures instead of one, depending on the presence of
`ComputedTextureSlices`
- I added two examples showcasing the slicing and tiling feature.

The addition of `ComputedTextureSlices` as a cache is to avoid querying
the image data, to retrieve its dimensions, every frame in a extract or
prepare stage. Also it reacts to changes so we can have stuff like this
(tiling example):


https://github.com/bevyengine/bevy/assets/26703856/a349a9f3-33c3-471f-8ef4-a0e5dfce3b01

# Related 

- [ ] Once #5103 or #10099 is merged I can enable tiling and slicing for
texture sheets as ui

# To discuss

There is an other option, to consider slice/tiling as part of the asset,
using the new asset preprocessing but I have no clue on how to do it.

Also, instead of retrieving the Image dimensions, we could use the same
system as the sprite sheet and have the user give the image dimensions
directly (grid). But I think it's less user friendly

---------

Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: ickshonpe <david.curthoys@googlemail.com>
Co-authored-by: Alice Cecile <alice.i.cecil@gmail.com>
2024-01-15 15:40:06 +00:00
Rob Parrett
9c972f037e
Fix missed explicit conversions in examples (#11261)
# Objective

A few of these were missed in #10878

## Solution

Fix em
2024-01-09 00:44:24 +00:00
Joona Aalto
a795de30b4
Use impl Into<A> for Assets::add (#10878)
# Motivation

When spawning entities into a scene, it is very common to create assets
like meshes and materials and to add them via asset handles. A common
setup might look like this:

```rust
fn setup(
    mut commands: Commands,
    mut meshes: ResMut<Assets<Mesh>>,
    mut materials: ResMut<Assets<StandardMaterial>>,
) {
    commands.spawn(PbrBundle {
        mesh: meshes.add(Mesh::from(shape::Cube { size: 1.0 })),
        material: materials.add(StandardMaterial::from(Color::RED)),
        ..default()
    });
}
```

Let's take a closer look at the part that adds the assets using `add`.

```rust
mesh: meshes.add(Mesh::from(shape::Cube { size: 1.0 })),
material: materials.add(StandardMaterial::from(Color::RED)),
```

Here, "mesh" and "material" are both repeated three times. It's very
explicit, but I find it to be a bit verbose. In addition to being more
code to read and write, the extra characters can sometimes also lead to
the code being formatted to span multiple lines even though the core
task, adding e.g. a primitive mesh, is extremely simple.

A way to address this is by using `.into()`:

```rust
mesh: meshes.add(shape::Cube { size: 1.0 }.into()),
material: materials.add(Color::RED.into()),
```

This is fine, but from the names and the type of `meshes`, we already
know what the type should be. It's very clear that `Cube` should be
turned into a `Mesh` because of the context it's used in. `.into()` is
just seven characters, but it's so common that it quickly adds up and
gets annoying.

It would be nice if you could skip all of the conversion and let Bevy
handle it for you:

```rust
mesh: meshes.add(shape::Cube { size: 1.0 }),
material: materials.add(Color::RED),
```

# Objective

Make adding assets more ergonomic by making `Assets::add` take an `impl
Into<A>` instead of `A`.

## Solution

`Assets::add` now takes an `impl Into<A>` instead of `A`, so e.g. this
works:

```rust
    commands.spawn(PbrBundle {
        mesh: meshes.add(shape::Cube { size: 1.0 }),
        material: materials.add(Color::RED),
        ..default()
    });
```

I also changed all examples to use this API, which increases consistency
as well because `Mesh::from` and `into` were being used arbitrarily even
in the same file. This also gets rid of some lines of code because
formatting is nicer.

---

## Changelog

- `Assets::add` now takes an `impl Into<A>` instead of `A`
- Examples don't use `T::from(K)` or `K.into()` when adding assets

## Migration Guide

Some `into` calls that worked previously might now be broken because of
the new trait bounds. You need to either remove `into` or perform the
conversion explicitly with `from`:

```rust
// Doesn't compile
let mesh_handle = meshes.add(shape::Cube { size: 1.0 }.into()),

// These compile
let mesh_handle = meshes.add(shape::Cube { size: 1.0 }),
let mesh_handle = meshes.add(Mesh::from(shape::Cube { size: 1.0 })),
```

## Concerns

I believe the primary concerns might be:

1. Is this too implicit?
2. Does this increase codegen bloat?

Previously, the two APIs were using `into` or `from`, and now it's
"nothing" or `from`. You could argue that `into` is slightly more
explicit than "nothing" in cases like the earlier examples where a
`Color` gets converted to e.g. a `StandardMaterial`, but I personally
don't think `into` adds much value even in this case, and you could
still see the actual type from the asset type.

As for codegen bloat, I doubt it adds that much, but I'm not very
familiar with the details of codegen. I personally value the user-facing
code reduction and ergonomics improvements that these changes would
provide, but it might be worth checking the other effects in more
detail.

Another slight concern is migration pain; apps might have a ton of
`into` calls that would need to be removed, and it did take me a while
to do so for Bevy itself (maybe around 20-40 minutes). However, I think
the fact that there *are* so many `into` calls just highlights that the
API could be made nicer, and I'd gladly migrate my own projects for it.
2024-01-08 22:14:43 +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
Nurzhan Sakén
8067e46049
Add example for pixel-perfect grid snapping in 2D (#8112)
# Objective

Provide an example of how to achieve pixel-perfect "grid snapping" in 2D
via rendering to a texture. This is a common use case in retro pixel art
game development.

## Solution

Render sprites to a canvas via a Camera, then use another (scaled up)
Camera to render the resulting canvas to the screen. This example is
based on the `3d/render_to_texture.rs` example. Furthermore, this
example demonstrates mixing retro-style graphics with high-resolution
graphics, as well as pixel-snapped rendering of a
`MaterialMesh2dBundle`.
2023-12-26 17:15:50 +00:00
Tygyh
1568d4a415
Reorder impl to be the same as the trait (#11076)
# Objective

- Make the implementation order consistent between all sources to fit
the order in the trait.

## Solution

- Change the implementation order.
2023-12-24 17:43:55 +00:00
Doonv
ba0f8f996f
Add insert_state to App. (#11043)
# Objective

Fix #10731.

## Solution

Rename `App::add_state<T>(&mut self)` to `init_state`, and add
`App::insert_state<T>(&mut self, state: T)`. I decided on these names
because they are more similar to `init_resource` and `insert_resource`.

I also removed the `States` trait's requirement for `Default`. Instead,
`init_state` requires `FromWorld`.

---

## Changelog

- Renamed `App::add_state` to `init_state`.
- Added `App::insert_state`.
- Removed the `States` trait's requirement for `Default`.

## Migration Guide

- Renamed `App::add_state` to `init_state`.
2023-12-21 14:09:24 +00:00
Thierry Berger
ced216f59a
Update winit dependency to 0.29 (#10702)
# Objective

- Update winit dependency to 0.29

## Changelog

### KeyCode changes

- Removed `ScanCode`, as it was [replaced by
KeyCode](https://github.com/rust-windowing/winit/blob/master/CHANGELOG.md#0292).
- `ReceivedCharacter.char` is now a `SmolStr`, [relevant
doc](https://docs.rs/winit/latest/winit/event/struct.KeyEvent.html#structfield.text).
- Changed most `KeyCode` values, and added more.

KeyCode has changed meaning. With this PR, it refers to physical
position on keyboard rather than the printed letter on keyboard keys.

In practice this means:
- On QWERTY keyboard layouts, nothing changes
- On any other keyboard layout, `KeyCode` no longer reflects the label
on key.
- This is "good". In bevy 0.12, when you used WASD for movement, users
with non-QWERTY keyboards couldn't play your game! This was especially
bad for non-latin keyboards. Now, WASD represents the physical keys. A
French player will press the ZQSD keys, which are near each other,
Kyrgyz players will use "Цфыв".
- This is "bad" as well. You can't know in advance what the label of the
key for input is. Your UI says "press WASD to move", even if in reality,
they should be pressing "ZQSD" or "Цфыв". You also no longer can use
`KeyCode` for text inputs. In any case, it was a pretty bad API for text
input. You should use `ReceivedCharacter` now instead.

### Other changes
- Use `web-time` rather than `instant` crate.
(https://github.com/rust-windowing/winit/pull/2836)
- winit did split `run_return` in `run_onDemand` and `pump_events`, I
did the same change in bevy_winit and used `pump_events`.
- Removed `return_from_run` from `WinitSettings` as `winit::run` now
returns on supported platforms.
- I left the example "return_after_run" as I think it's still useful.
- This winit change is done partly to allow to create a new window after
quitting all windows: https://github.com/emilk/egui/issues/1918 ; this
PR doesn't address.
- added `width` and `height` properties in the `canvas` from wasm
example
(https://github.com/bevyengine/bevy/pull/10702#discussion_r1420567168)

## Known regressions (important follow ups?)
- Provide an API for reacting when a specific key from current layout
was released.
- possible solutions: use winit::Key from winit::KeyEvent ; mapping
between KeyCode and Key ; or .
- We don't receive characters through alt+numpad (e.g. alt + 151 = "ù")
anymore ; reproduced on winit example "ime". maybe related to
https://github.com/rust-windowing/winit/issues/2945
- (windows) Window content doesn't refresh at all when resizing. By
reading https://github.com/rust-windowing/winit/issues/2900 ; I suspect
we should just fire a `window.request_redraw();` from `AboutToWait`, and
handle actual redrawing within `RedrawRequested`. I'm not sure how to
move all that code so I'd appreciate it to be a follow up.
- (windows) unreleased winit fix for using set_control_flow in
AboutToWait https://github.com/rust-windowing/winit/issues/3215 ; ⚠️ I'm
not sure what the implications are, but that feels bad 🤔

## Follow up 

I'd like to avoid bloating this PR, here are a few follow up tasks
worthy of a separate PR, or new issue to track them once this PR is
closed, as they would either complicate reviews, or at risk of being
controversial:
- remove CanvasParentResizePlugin
(https://github.com/bevyengine/bevy/pull/10702#discussion_r1417068856)
- avoid mentionning explicitly winit in docs from bevy_window ?
- NamedKey integration on bevy_input:
https://github.com/rust-windowing/winit/pull/3143 introduced a new
NamedKey variant. I implemented it only on the converters but we'd
benefit making the same changes to bevy_input.
- Add more info in KeyboardInput
https://github.com/bevyengine/bevy/pull/10702#pullrequestreview-1748336313
- https://github.com/bevyengine/bevy/pull/9905 added a workaround on a
bug allegedly fixed by winit 0.29. We should check if it's still
necessary.
- update to raw_window_handle 0.6
  - blocked by wgpu
- Rename `KeyCode` to `PhysicalKeyCode`
https://github.com/bevyengine/bevy/pull/10702#discussion_r1404595015
- remove `instant` dependency, [replaced
by](https://github.com/rust-windowing/winit/pull/2836) `web_time`), we'd
need to update to :
  - fastrand >= 2.0
- [`async-executor`](https://github.com/smol-rs/async-executor) >= 1.7
    - [`futures-lite`](https://github.com/smol-rs/futures-lite) >= 2.0
- Verify license, see
[discussion](https://github.com/bevyengine/bevy/pull/8745#discussion_r1402439800)
  - we might be missing a short notice or description of changes made
- Consider using https://github.com/rust-windowing/cursor-icon directly
rather than vendoring it in bevy.
- investigate [this
unwrap](https://github.com/bevyengine/bevy/pull/8745#discussion_r1387044986)
(`winit_window.canvas().unwrap();`)
- Use more good things about winit's update
- https://github.com/bevyengine/bevy/pull/10689#issuecomment-1823560428
## Migration Guide

This PR should have one.
2023-12-21 07:40:47 +00:00
Anton Iacobaeus
ca1874e6c6
Update texture_atlas example with different padding and sampling (#10073)
# Objective

- Expand the texture_atlas example with padding and show how it can
resolve sprite bleeding for different types of sampling.
- Fixes #9522
## Solution
Updated the texture_atlas example by adding 4 different texture atlases:
1. linear, no padding
2. linear, padding
3. nearest neighbor, no padding
4. nearest neighbor, padding

Now renders one padded and one unpadded texture atlas, and the same
upscaled sprite from each of the new texture atlases. See the screenshot
below (taken on 1080p monitor).


![Screenshot from 2023-10-10
08-37-43](https://github.com/bevyengine/bevy/assets/46004494/4cef707c-e117-4835-b2c8-66503d8c275f)

**From left->right:** linear no padding, nearest no padding, linear
padding, nearest padding.

---

---------

Co-authored-by: davidasberg <david.aasberg@gmail.com>
2023-12-14 18:48:38 +00:00
Mateusz Wachowiak
1f97717a3d
Rename Input to ButtonInput (#10859)
# Objective

- Resolves #10853 

## Solution

- ~~Changed the name of `Input` struct to `PressableInput`.~~
- Changed the name of `Input` struct to `ButtonInput`.

## Migration Guide

- Breaking Change: Users need to rename `Input` to `ButtonInput` in
their projects.
2023-12-06 20:32:34 +00:00
akimakinai
f90248b052
Remove unnecessary ResMut in examples (#10879)
# Objective

- Examples containing `ResMut`s that are never mutated can be confusing
for readers.

## Solution

- Changes them to `Res`.
2023-12-05 15:42:32 +00:00
ickshonpe
166686e0f2
Rename TextAlignment to JustifyText. (#10854)
# Objective

The name `TextAlignment` is really deceptive and almost every new user
gets confused about the differences between aligning text with
`TextAlignment`, aligning text with `Style` and aligning text with
anchor (when using `Text2d`).

## Solution

* Rename `TextAlignment` to `JustifyText`. The associated helper methods
are also renamed.
* Improve the doc comments for text explaining explicitly how the
`JustifyText` component affects the arrangement of text.
* Add some extra cases to the `text_debug` example that demonstate the
differences between alignment using `JustifyText` and alignment using
`Style`.
<img width="757" alt="text_debug_2"
src="https://github.com/bevyengine/bevy/assets/27962798/9d53e647-93f9-4bc7-8a20-0d9f783304d2">

---

## Changelog
* `TextAlignment` has been renamed to `JustifyText`
* `TextBundle::with_text_alignment` has been renamed to
`TextBundle::with_text_justify`
* `Text::with_alignment` has been renamed to `Text::with_justify`
* The `text_alignment` field of `TextMeasureInfo` has been renamed to
`justification`

## Migration Guide
* `TextAlignment` has been renamed to `JustifyText`
* `TextBundle::with_text_alignment` has been renamed to
`TextBundle::with_text_justify`
* `Text::with_alignment` has been renamed to `Text::with_justify`
* The `text_alignment` field of `TextMeasureInfo` has been renamed to
`justification`
2023-12-05 03:00:41 +00:00
tygyh
fd308571c4
Remove unnecessary path prefixes (#10749)
# Objective

- Shorten paths by removing unnecessary prefixes

## Solution

- Remove the prefixes from many paths which do not need them. Finding
the paths was done automatically using built-in refactoring tools in
Jetbrains RustRover.
2023-11-28 23:43:40 +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
Connor King
ab300d0ed9
Gizmo Arrows (#10550)
## Objective

- Add an arrow gizmo as suggested by #9400 

## Solution

(excuse my Protomen music)


https://github.com/bevyengine/bevy/assets/14184826/192adf24-079f-4a4b-a17b-091e892974ec

Wasn't horribly hard when i remembered i can change coordinate systems
whenever I want. Gave them four tips (as suggested by @alice-i-cecile in
discord) instead of trying to decide what direction the tips should
point.

Made the tip length default to 1/10 of the arrow's length, which looked
good enough to me. Hard-coded the angle from the body to the tips to 45
degrees.

## Still TODO

- [x] actual doc comments
- [x] doctests
- [x] `ArrowBuilder.with_tip_length()`

---

## Changelog

- Added `gizmos.arrow()` and `gizmos.arrow_2d()`
- Added arrows to `2d_gizmos` and `3d_gizmos` examples

## Migration Guide

N/A

---------

Co-authored-by: Nicola Papale <nicopap@users.noreply.github.com>
2023-11-15 14:19:15 +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
Aevyrie
1d8d78ef0e
Update color and naming for consistency (#10367)
The `ClearColor` PR was merged before I was quite finished. This fixes a
few errors, and addresses Cart's feedback about the pixel perfect
example by updating the sprite colors to match the existing bevy bird
branding colors.


![image](https://github.com/bevyengine/bevy/assets/2632925/33722c45-ed66-4d3a-af11-f4197611a13c)
2023-11-04 02:09:23 +00:00
Aevyrie
1918608b02
Update default ClearColor to better match Bevy's branding (#10339)
# Objective

- Changes the default clear color to match the code block color on
Bevy's website.

## Solution

- Changed the clear color, updated text in examples to ensure adequate
contrast. Inconsistent usage of white text color set to use the default
color instead, which is already white.
- Additionally, updated the `3d_scene` example to make it look a bit
better, and use bevy's branding colors.


![image](https://github.com/bevyengine/bevy/assets/2632925/540a22c0-826c-4c33-89aa-34905e3e313a)
2023-11-03 12:57:38 +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
Nuutti Kotivuori
3d79dc4cdc
Unify FixedTime and Time while fixing several problems (#8964)
# Objective

Current `FixedTime` and `Time` have several problems. This pull aims to
fix many of them at once.

- If there is a longer pause between app updates, time will jump forward
a lot at once and fixed time will iterate on `FixedUpdate` for a large
number of steps. If the pause is merely seconds, then this will just
mean jerkiness and possible unexpected behaviour in gameplay. If the
pause is hours/days as with OS suspend, the game will appear to freeze
until it has caught up with real time.
- If calculating a fixed step takes longer than specified fixed step
period, the game will enter a death spiral where rendering each frame
takes longer and longer due to more and more fixed step updates being
run per frame and the game appears to freeze.
- There is no way to see current fixed step elapsed time inside fixed
steps. In order to track this, the game designer needs to add a custom
system inside `FixedUpdate` that calculates elapsed or step count in a
resource.
- Access to delta time inside fixed step is `FixedStep::period` rather
than `Time::delta`. This, coupled with the issue that `Time::elapsed`
isn't available at all for fixed steps, makes it that time requiring
systems are either implemented to be run in `FixedUpdate` or `Update`,
but rarely work in both.
- Fixes #8800 
- Fixes #8543 
- Fixes #7439
- Fixes #5692

## Solution

- Create a generic `Time<T>` clock that has no processing logic but
which can be instantiated for multiple usages. This is also exposed for
users to add custom clocks.
- Create three standard clocks, `Time<Real>`, `Time<Virtual>` and
`Time<Fixed>`, all of which contain their individual logic.
- Create one "default" clock, which is just `Time` (or `Time<()>`),
which will be overwritten from `Time<Virtual>` on each update, and
`Time<Fixed>` inside `FixedUpdate` schedule. This way systems that do
not care specifically which time they track can work both in `Update`
and `FixedUpdate` without changes and the behaviour is intuitive.
- Add `max_delta` to virtual time update, which limits how much can be
added to virtual time by a single update. This fixes both the behaviour
after a long freeze, and also the death spiral by limiting how many
fixed timestep iterations there can be per update. Possible future work
could be adding `max_accumulator` to add a sort of "leaky bucket" time
processing to possibly smooth out jumps in time while keeping frame rate
stable.
- Many minor tweaks and clarifications to the time functions and their
documentation.

## Changelog

- `Time::raw_delta()`, `Time::raw_elapsed()` and related methods are
moved to `Time<Real>::delta()` and `Time<Real>::elapsed()` and now match
`Time` API
- `FixedTime` is now `Time<Fixed>` and matches `Time` API. 
- `Time<Fixed>` default timestep is now 64 Hz, or 15625 microseconds.
- `Time` inside `FixedUpdate` now reflects fixed timestep time, making
systems portable between `Update ` and `FixedUpdate`.
- `Time::pause()`, `Time::set_relative_speed()` and related methods must
now be called as `Time<Virtual>::pause()` etc.
- There is a new `max_delta` setting in `Time<Virtual>` that limits how
much the clock can jump by a single update. The default value is 0.25
seconds.
- Removed `on_fixed_timer()` condition as `on_timer()` does the right
thing inside `FixedUpdate` now.

## Migration Guide

- Change all `Res<Time>` instances that access `raw_delta()`,
`raw_elapsed()` and related methods to `Res<Time<Real>>` and `delta()`,
`elapsed()`, etc.
- Change access to `period` from `Res<FixedTime>` to `Res<Time<Fixed>>`
and use `delta()`.
- The default timestep has been changed from 60 Hz to 64 Hz. If you wish
to restore the old behaviour, use
`app.insert_resource(Time::<Fixed>::from_hz(60.0))`.
- Change `app.insert_resource(FixedTime::new(duration))` to
`app.insert_resource(Time::<Fixed>::from_duration(duration))`
- Change `app.insert_resource(FixedTime::new_from_secs(secs))` to
`app.insert_resource(Time::<Fixed>::from_seconds(secs))`
- Change `system.on_fixed_timer(duration)` to
`system.on_timer(duration)`. Timers in systems placed in `FixedUpdate`
schedule automatically use the fixed time clock.
- Change `ResMut<Time>` calls to `pause()`, `is_paused()`,
`set_relative_speed()` and related methods to `ResMut<Time<Virtual>>`
calls. The API is the same, with the exception that `relative_speed()`
will return the actual last ste relative speed, while
`effective_relative_speed()` returns 0.0 if the time is paused and
corresponds to the speed that was set when the update for the current
frame started.

## Todo

- [x] Update pull name and description
- [x] Top level documentation on usage
- [x] Fix examples
- [x] Decide on default `max_delta` value
- [x] Decide naming of the three clocks: is `Real`, `Virtual`, `Fixed`
good?
- [x] Decide if the three clock inner structures should be in prelude
- [x] Decide on best way to configure values at startup: is manually
inserting a new clock instance okay, or should there be config struct
separately?
- [x] Fix links in docs
- [x] Decide what should be public and what not
- [x] Decide how `wrap_period` should be handled when it is changed
- [x] ~~Add toggles to disable setting the clock as default?~~ No,
separate pull if needed.
- [x] Add tests
- [x] Reformat, ensure adheres to conventions etc.
- [x] Build documentation and see that it looks correct

## Contributors

Huge thanks to @alice-i-cecile and @maniwani while building this pull.
It was a shared effort!

---------

Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: Cameron <51241057+maniwani@users.noreply.github.com>
Co-authored-by: Jerome Humbert <djeedai@gmail.com>
2023-10-16 01:57:55 +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
Rob Parrett
8681d1cb04
Fix animate_scale scaling z value in text2d example (#9769)
# Objective

I noticed this while testing #9733.

It's not causing any problems, but we shouldn't teach users to scale 2d
stuff in z.

## Solution

Only scale in x and y.
2023-09-13 19:25:44 +00:00
ira
f3ab38a802
Add example for Camera::viewport_to_world (#7179)
Fixes #7177

---------

Co-authored-by: Rob Parrett <robparrett@gmail.com>
2023-09-11 18:52:11 +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