# Objective
- It's possible to have errors in a draw command, but these errors are
ignored
## Solution
- Return a result with the error
## Changelog
Renamed `RenderCommandResult::Failure` to `RenderCommandResult::Skip`
Added a `reason` string parameter to `RenderCommandResult::Failure`
## Migration Guide
If you were using `RenderCommandResult::Failure` to just ignore an error
and retry later, use `RenderCommandResult::Skip` instead.
This wasn't intentional, but this PR should also help with
https://github.com/bevyengine/bevy/issues/12660 since we can turn a few
unwraps into error messages now.
---------
Co-authored-by: Charlotte McElwain <charlotte.c.mcelwain@gmail.com>
Switches `Msaa` from being a globally configured resource to a per
camera view component.
Closes#7194
# Objective
Allow individual views to describe their own MSAA settings. For example,
when rendering to different windows or to different parts of the same
view.
## Solution
Make `Msaa` a component that is required on all camera bundles.
## Testing
Ran a variety of examples to ensure that nothing broke.
TODO:
- [ ] Make sure android still works per previous comment in
`extract_windows`.
---
## Migration Guide
`Msaa` is no longer configured as a global resource, and should be
specified on each spawned camera if a non-default setting is desired.
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: François Mockers <francois.mockers@vleue.com>
## Objective
Make the docs say the right thing.
## Solution
Edit the docs so they say the right thing.
Seems like overtime the example has changed but the comment did not
change with it. It originally was a AND but is now an OR.
# Objective
When the user renders multiple cameras to the same output texture, it
can sometimes be confusing what `ClearColorConfig` is necessary for each
camera to avoid overwriting the previous camera's output. This is
particular true in cases where the user uses mixed HDR cameras, which
means that their scene is being rendered to different internal textures.
## Solution
When a view has a configured viewport, set the GPU scissor in the
upscaling node so we don't overwrite areas that were written to by other
cameras.
## Testing
Ran the `split_screen` example.
# Objective
Fixes#7433
Alternative to #14323
## Solution
Add `DefaultPlugins` so we actually have tracing spans when using
`trace_tracy` or `trace_chrome`.
## Testing
```
cargo run --release --features trace_tracy --example transform_hierarchy large_tree
```
This now connects to Tracy and sends a bunch of data.
# Objective
- Fixes: https://github.com/bevyengine/bevy/issues/14036
## Solution
- Add a world space transformation for the environment sample direction.
## Testing
- I have tested the newly added `transform` field using the newly added
`rotate_environment_map` example.
https://github.com/user-attachments/assets/2de77c65-14bc-48ee-b76a-fb4e9782dbdb
## Migration Guide
- Since we have added a new filed to the `EnvironmentMapLight` struct,
users will need to include `..default()` or some rotation value in their
initialization code.
# Objective
Fill a gap in the functionality of our curve constructions by allowing
users to easily build cyclic curves from control data.
## Solution
Here I opted for something lightweight and discoverable. There is a new
`CyclicCubicGenerator` trait with a method `to_curve_cyclic` which uses
splines' control data to create curves that are cyclic. For now, its
signature is exactly like that of `CubicGenerator` — `to_curve_cyclic`
just yields a `CubicCurve`:
```rust
/// Implement this on cubic splines that can generate a cyclic cubic curve from their spline parameters.
///
/// This makes sense only when the control data can be interpreted cyclically.
pub trait CyclicCubicGenerator<P: VectorSpace> {
/// Build a cyclic [`CubicCurve`] by computing the interpolation coefficients for each curve segment.
fn to_curve_cyclic(&self) -> CubicCurve<P>;
}
```
This trait has been implemented for `CubicHermite`,
`CubicCardinalSpline`, `CubicBSpline`, and `LinearSpline`:
<img width="753" alt="Screenshot 2024-07-01 at 8 58 27 PM"
src="https://github.com/bevyengine/bevy/assets/2975848/69ae0802-3b78-4fb9-b73a-6f842cf3b33c">
<img width="628" alt="Screenshot 2024-07-01 at 9 00 14 PM"
src="https://github.com/bevyengine/bevy/assets/2975848/2992175a-a96c-40fc-b1a1-5206c3572cde">
<img width="606" alt="Screenshot 2024-07-01 at 8 59 36 PM"
src="https://github.com/bevyengine/bevy/assets/2975848/9e99eb3a-dbe6-42da-886c-3d3e00410d03">
<img width="603" alt="Screenshot 2024-07-01 at 8 59 01 PM"
src="https://github.com/bevyengine/bevy/assets/2975848/d037bc0c-396a-43af-ab5c-fad9a29417ef">
(Each type pictured respectively with the control points rendered as
green spheres; tangents not pictured in the case of the Hermite spline.)
These curves are all parametrized so that the output of `to_curve` and
the output of `to_curve_cyclic` are similar. For instance, in
`CubicCardinalSpline`, the first output segment is a curve segment
joining the first and second control points in each, although it is
constructed differently. In the other cases, the segments from
`to_curve` are a subset of those in `to_curve_cyclic`, with the new
segments appearing at the end.
## Testing
I rendered cyclic splines from control data and made sure they looked
reasonable. Existing tests are intact for splines where previous code
was modified. (Note that the coefficient computation for cyclic spline
segments is almost verbatim identical to that of their non-cyclic
counterparts.)
The Bezier benchmarks also look fine.
---
## Changelog
- Added `CyclicCubicGenerator` trait to `bevy_math::cubic_splines` for
creating cyclic curves from control data.
- Implemented `CyclicCubicGenerator` for `CubicHermite`,
`CubicCardinalSpline`, `CubicBSpline`, and `LinearSpline`.
- `bevy_math` now depends on `itertools`.
---
## Discussion
### Design decisions
The biggest thing here is just the approach taken in the first place:
namely, the cyclic constructions use new methods on the same old
structs. This choice was made to reduce friction and increase
discoverability but also because creating new ones just seemed
unnecessary: the underlying data would have been the same, so creating
something like "`CyclicCubicBSpline`" whose internally-held control data
is regarded as cyclic in nature doesn't really accomplish much — the end
result for the user is basically the same either way.
Similarly, I don't presently see a pressing need for `to_curve_cyclic`
to output something other than a `CubicCurve`, although changing this in
the future may be useful. See below.
A notable omission here is that `CyclicCubicGenerator` is not
implemented for `CubicBezier`. This is not a gap waiting to be filled —
`CubicBezier` just doesn't have enough data to join its start with its
end without just making up the requisite control points wholesale. In
all the cases where `CyclicCubicGenerator` has been implemented here,
the fashion in which the ends are connected is quite natural and follows
the semantics of the associated spline construction.
### Future direction
There are two main things here:
1. We should investigate whether we should do something similar for
NURBS. I just don't know that much about NURBS at the moment, so I
regarded this as out of scope for the PR.
2. We may eventually want to change the output type of
`CyclicCubicGenerator::to_curve_cyclic` to a type which reifies the
cyclic nature of the curve output. This wasn't done in this PR because
I'm unsure how much value a type-level guarantee of cyclicity actually
has, but if some useful features make sense only in the case of cyclic
curves, this might be worth pursuing.
This commit uses the [`offset-allocator`] crate to combine vertex and
index arrays from different meshes into single buffers. Since the
primary source of `wgpu` overhead is from validation and synchronization
when switching buffers, this significantly improves Bevy's rendering
performance on many scenes.
This patch is a more flexible version of #13218, which also used slabs.
Unlike #13218, which used slabs of a fixed size, this commit implements
slabs that start small and can grow. In addition to reducing memory
usage, supporting slab growth reduces the number of vertex and index
buffer switches that need to happen during rendering, leading to
improved performance. To prevent pathological fragmentation behavior,
slabs are capped to a maximum size, and mesh arrays that are too large
get their own dedicated slabs.
As an additional improvement over #13218, this commit allows the
application to customize all allocator heuristics. The
`MeshAllocatorSettings` resource contains values that adjust the minimum
and maximum slab sizes, the cutoff point at which meshes get their own
dedicated slabs, and the rate at which slabs grow. Hopefully-sensible
defaults have been chosen for each value.
Unfortunately, WebGL 2 doesn't support the *base vertex* feature, which
is necessary to pack vertex arrays from different meshes into the same
buffer. `wgpu` represents this restriction as the downlevel flag
`BASE_VERTEX`. This patch detects that bit and ensures that all vertex
buffers get dedicated slabs on that platform. Even on WebGL 2, though,
we can combine all *index* arrays into single buffers to reduce buffer
changes, and we do so.
The following measurements are on Bistro:
Overall frame time improves from 8.74 ms to 5.53 ms (1.58x speedup):
Render system time improves from 6.57 ms to 3.54 ms (1.86x speedup):
Opaque pass time improves from 4.64 ms to 2.33 ms (1.99x speedup):
## Migration Guide
### Changed
* Vertex and index buffers for meshes may now be packed alongside other
buffers, for performance.
* `GpuMesh` has been renamed to `RenderMesh`, to reflect the fact that
it no longer directly stores handles to GPU objects.
* Because meshes no longer have their own vertex and index buffers, the
responsibility for the buffers has moved from `GpuMesh` (now called
`RenderMesh`) to the `MeshAllocator` resource. To access the vertex data
for a mesh, use `MeshAllocator::mesh_vertex_slice`. To access the index
data for a mesh, use `MeshAllocator::mesh_index_slice`.
[`offset-allocator`]: https://github.com/pcwalton/offset-allocator
# Objective
Many functions can be converted to `DynamicFunction` using
`IntoFunction`. Unfortunately, we are limited by Rust itself and the
implementations are far from exhaustive. For example, we can't convert
functions with more than 16 arguments. Additionally, we can't handle
returns with lifetimes not tied to the lifetime of the first argument.
In such cases, users will have to create their `DynamicFunction`
manually.
Let's take the following function:
```rust
fn get(index: usize, list: &Vec<String>) -> &String {
&list[index]
}
```
This function cannot be converted to a `DynamicFunction` via
`IntoFunction` due to the lifetime of the return value being tied to the
second argument. Therefore, we need to construct the `DynamicFunction`
manually:
```rust
DynamicFunction::new(
|mut args, info| {
let list = args
.pop()
.unwrap()
.take_ref::<Vec<String>>(&info.args()[1])?;
let index = args.pop().unwrap().take_owned::<usize>(&info.args()[0])?;
Ok(Return::Ref(get(index, list)))
},
FunctionInfo::new()
.with_name("get")
.with_args(vec![
ArgInfo:🆕:<usize>(0).with_name("index"),
ArgInfo:🆕:<&Vec<String>>(1).with_name("list"),
])
.with_return_info(ReturnInfo:🆕:<&String>()),
);
```
While still a small and straightforward snippet, there's a decent amount
going on here. There's a lot of room for improvements when it comes to
ergonomics and readability.
The goal of this PR is to address those issues.
## Solution
Improve the ergonomics and readability of manually created
`DynamicFunction`s.
Some of the major changes:
1. Removed the need for `&ArgInfo` when reifying arguments (i.e. the
`&info.args()[1]` calls)
2. Added additional `pop` methods on `ArgList` to handle both popping
and casting
3. Added `take` methods on `ArgList` for taking the arguments out in
order
4. Removed the need for `&FunctionInfo` in the internal closure (Change
1 made it no longer necessary)
5. Added methods to automatically handle generating `ArgInfo` and
`ReturnInfo`
With all these changes in place, we get something a lot nicer to both
write and look at:
```rust
DynamicFunction::new(
|mut args| {
let index = args.take::<usize>()?;
let list = args.take::<&Vec<String>>()?;
Ok(Return::Ref(get(index, list)))
},
FunctionInfo::new()
.with_name("get")
.with_arg::<usize>("index")
.with_arg::<&Vec<String>>("list")
.with_return::<&String>(),
);
```
Alternatively, to rely on type inference for taking arguments, you could
do:
```rust
DynamicFunction::new(
|mut args| {
let index = args.take_owned()?;
let list = args.take_ref()?;
Ok(Return::Ref(get(index, list)))
},
FunctionInfo::new()
.with_name("get")
.with_arg::<usize>("index")
.with_arg::<&Vec<String>>("list")
.with_return::<&String>(),
);
```
## Testing
You can test locally by running:
```
cargo test --package bevy_reflect
```
---
## Changelog
- Removed `&ArgInfo` argument from `FromArg::from_arg` trait method
- Removed `&ArgInfo` argument from `Arg::take_***` methods
- Added `ArgValue`
- `Arg` is now a struct containing an `ArgValue` and an argument `index`
- `Arg::take_***` methods now require `T` is also `TypePath`
- Added `Arg::new`, `Arg::index`, `Arg::value`, `Arg::take_value`, and
`Arg::take` methods
- Replaced `ArgId` in `ArgError` with just the argument `index`
- Added `ArgError::EmptyArgList`
- Renamed `ArgList::push` to `ArgList::push_arg`
- Added `ArgList::pop_arg`, `ArgList::pop_owned`, `ArgList::pop_ref`,
and `ArgList::pop_mut`
- Added `ArgList::take_arg`, `ArgList::take_owned`, `ArgList::take_ref`,
`ArgList::take_mut`, and `ArgList::take`
- `ArgList::pop` is now generic
- Renamed `FunctionError::InvalidArgCount` to
`FunctionError::ArgCountMismatch`
- The closure given to `DynamicFunction::new` no longer has a
`&FunctionInfo` argument
- Added `FunctionInfo::with_arg`
- Added `FunctionInfo::with_return`
## Internal Migration Guide
> [!important]
> Function reflection was introduced as part of the 0.15 dev cycle. This
migration guide was written for developers relying on `main` during this
cycle, and is not a breaking change coming from 0.14.
* The `FromArg::from_arg` trait method and the `Arg::take_***` methods
no longer take a `&ArgInfo` argument.
* What used to be `Arg` is now `ArgValue`. `Arg` is now a struct which
contains an `ArgValue`.
* `Arg::take_***` methods now require `T` is also `TypePath`
* Instances of `id: ArgId` in `ArgError` have been replaced with `index:
usize`
* `ArgList::push` is now `ArgList::push_arg`. It also takes the new
`ArgValue` type.
* `ArgList::pop` has become `ArgList::pop_arg` and now returns
`ArgValue`. `Arg::pop` now takes a generic type and downcasts to that
type. It's recommended to use `ArgList::take` and friends instead since
they allow removing the arguments from the list in the order they were
pushed (rather than reverse order).
* `FunctionError::InvalidArgCount` is now
`FunctionError::ArgCountMismatch`
* The closure given to `DynamicFunction::new` no longer has a
`&FunctionInfo` argument. This argument can be removed.
# Objective
- Continue to pare down the uses on NonSend resources in the engine. In
this case, EventLoopProxy used to be `!Sync`, but is now `Sync` in the
latest version of winit.
## Solution
- New type `EventLoopProxy` as `EventLoopProxyWrapper` to make it into a
normal resource.
- Update the `custom_user_event` example as it no longer needs to
indirectly access the `EventLoopProxy` through a static variable
anymore.
## Testing
- Ran the example. The resource exists just for users to use, so there
aren't any in engine uses for it currently.
---
## Changelog
- make EventLoopProxy into a regular resource.
## Migration Guide
`EventLoopProxy` has been renamed to `EventLoopProxyWrapper` and is now
`Send`, making it an ordinary resource.
Before:
```rust
event_loop_system(event_loop: NonSend<EventLoopProxy<MyEvent>>) {
event_loop.send_event(MyEvent);
}
```
After:
```rust
event_loop_system(event_loop: Res<EventLoopProxy<MyEvent>>) {
event_loop.send_event(MyEvent);
}
```
# Objective
As mentioned in
[this](https://github.com/bevyengine/bevy/pull/13152#issuecomment-2198387297)
comment, creating a function registry (see #14098) is a bit difficult
due to the requirements of `DynamicFunction`. Internally, a
`DynamicFunction` contains a `Box<dyn FnMut>` (the function that reifies
reflected arguments and calls the actual function), which requires `&mut
self` in order to be called.
This means that users would require a mutable reference to the function
registry for it to be useful— which isn't great. And they can't clone
the `DynamicFunction` either because cloning an `FnMut` isn't really
feasible (wrapping it in an `Arc` would allow it to be cloned but we
wouldn't be able to call the clone since we need a mutable reference to
the `FnMut`, which we can't get with multiple `Arc`s still alive,
requiring us to also slap in a `Mutex`, which adds additional overhead).
And we don't want to just replace the `dyn FnMut` with `dyn Fn` as that
would prevent reflecting closures that mutate their environment.
Instead, we need to introduce a new type to split the requirements of
`DynamicFunction`.
## Solution
Introduce new types for representing closures.
Specifically, this PR introduces `DynamicClosure` and
`DynamicClosureMut`. Similar to how `IntoFunction` exists for
`DynamicFunction`, two new traits were introduced: `IntoClosure` and
`IntoClosureMut`.
Now `DynamicFunction` stores a `dyn Fn` with a `'static` lifetime.
`DynamicClosure` also uses a `dyn Fn` but has a lifetime, `'env`, tied
to its environment. `DynamicClosureMut` is most like the old
`DynamicFunction`, keeping the `dyn FnMut` and also typing its lifetime,
`'env`, to the environment
Here are some comparison tables:
| | `DynamicFunction` | `DynamicClosure` | `DynamicClosureMut` |
| - | ----------------- | ---------------- | ------------------- |
| Callable with `&self` | ✅ | ✅ | ❌ |
| Callable with `&mut self` | ✅ | ✅ | ✅ |
| Allows for non-`'static` lifetimes | ❌ | ✅ | ✅ |
| | `IntoFunction` | `IntoClosure` | `IntoClosureMut` |
| - | -------------- | ------------- | ---------------- |
| Convert `fn` functions | ✅ | ✅ | ✅ |
| Convert `fn` methods | ✅ | ✅ | ✅ |
| Convert anonymous functions | ✅ | ✅ | ✅ |
| Convert closures that capture immutable references | ❌ | ✅ | ✅ |
| Convert closures that capture mutable references | ❌ | ❌ | ✅ |
| Convert closures that capture owned values | ❌[^1] | ✅ | ✅ |
[^1]: Due to limitations in Rust, `IntoFunction` can't be implemented
for just functions (unless we forced users to manually coerce them to
function pointers first). So closures that meet the trait requirements
_can technically_ be converted into a `DynamicFunction` as well. To both
future-proof and reduce confusion, though, we'll just pretend like this
isn't a thing.
```rust
let mut list: Vec<i32> = vec![1, 2, 3];
// `replace` is a closure that captures a mutable reference to `list`
let mut replace = |index: usize, value: i32| -> i32 {
let old_value = list[index];
list[index] = value;
old_value
};
// Convert the closure into a dynamic closure using `IntoClosureMut::into_closure_mut`
let mut func: DynamicClosureMut = replace.into_closure_mut();
// Dynamically call the closure:
let args = ArgList::default().push_owned(1_usize).push_owned(-2_i32);
let value = func.call_once(args).unwrap().unwrap_owned();
// Check the result:
assert_eq!(value.take::<i32>().unwrap(), 2);
assert_eq!(list, vec![1, -2, 3]);
```
### `ReflectFn`/`ReflectFnMut`
To make extending the function reflection system easier (the blanket
impls for `IntoFunction`, `IntoClosure`, and `IntoClosureMut` are all
incredibly short), this PR generalizes callables with two new traits:
`ReflectFn` and `ReflectFnMut`.
These traits mimic `Fn` and `FnMut` but allow for being called via
reflection. In fact, their blanket implementations are identical save
for `ReflectFn` being implemented over `Fn` types and `ReflectFnMut`
being implemented over `FnMut` types.
And just as `Fn` is a subtrait of `FnMut`, `ReflectFn` is a subtrait of
`ReflectFnMut`. So anywhere that expects a `ReflectFnMut` can also be
given a `ReflectFn`.
To reiterate, these traits aren't 100% necessary. They were added in
purely for extensibility. If we decide to split things up differently or
add new traits/types in the future, then those changes should be much
simpler to implement.
### `TypedFunction`
Because of the split into `ReflectFn` and `ReflectFnMut`, we needed a
new way to access the function type information. This PR moves that
concept over into `TypedFunction`.
Much like `Typed`, this provides a way to access a function's
`FunctionInfo`.
By splitting this trait out, it helps to ensure the other traits are
focused on a single responsibility.
### Internal Macros
The original function PR (#13152) implemented `IntoFunction` using a
macro which was passed into an `all_tuples!` macro invocation. Because
we needed the same functionality for these new traits, this PR has
copy+pasted that code for `ReflectFn`, `ReflectFnMut`, and
`TypedFunction`— albeit with some differences between them.
Originally, I was going to try and macro-ify the impls and where clauses
such that we wouldn't have to straight up duplicate a lot of this logic.
However, aside from being more complex in general, autocomplete just
does not play nice with such heavily nested macros (tried in both
RustRover and VSCode). And both of those problems told me that it just
wasn't worth it: we need to ensure the crate is easily maintainable,
even at the cost of duplicating code.
So instead, I made sure to simplify the macro code by removing all
fully-qualified syntax and cutting the where clauses down to the bare
essentials, which helps to clean up a lot of the visual noise. I also
tried my best to document the macro logic in certain areas (I may even
add a bit more) to help with maintainability for future devs.
### Documentation
Documentation for this module was a bit difficult for me. So many of
these traits and types are very interconnected. And each trait/type has
subtle differences that make documenting it in a single place, like at
the module level, difficult to do cleanly. Describing the valid
signatures is also challenging to do well.
Hopefully what I have here is okay. I think I did an okay job, but let
me know if there any thoughts on ways to improve it. We can also move
such a task to a followup PR for more focused discussion.
## Testing
You can test locally by running:
```
cargo test --package bevy_reflect
```
---
## Changelog
- Added `DynamicClosure` struct
- Added `DynamicClosureMut` struct
- Added `IntoClosure` trait
- Added `IntoClosureMut` trait
- Added `ReflectFn` trait
- Added `ReflectFnMut` trait
- Added `TypedFunction` trait
- `IntoFunction` now only works for standard Rust functions
- `IntoFunction` no longer takes a lifetime parameter
- `DynamicFunction::call` now only requires `&self`
- Removed `DynamicFunction::call_once`
- Changed the `IntoReturn::into_return` signature to include a where
clause
## Internal Migration Guide
> [!important]
> Function reflection was introduced as part of the 0.15 dev cycle. This
migration guide was written for developers relying on `main` during this
cycle, and is not a breaking change coming from 0.14.
### `IntoClosure`
`IntoFunction` now only works for standard Rust functions. Calling
`IntoFunction::into_function` on a closure that captures references to
its environment (either mutable or immutable), will no longer compile.
Instead, you will need to use either `IntoClosure::into_closure` to
create a `DynamicClosure` or `IntoClosureMut::into_closure_mut` to
create a `DynamicClosureMut`, depending on your needs:
```rust
let punct = String::from("!");
let print = |value: String| {
println!("{value}{punct}");
};
// BEFORE
let func: DynamicFunction = print.into_function();
// AFTER
let func: DynamicClosure = print.into_closure();
```
### `IntoFunction` lifetime
Additionally, `IntoFunction` no longer takes a lifetime parameter as it
always expects a `'static` lifetime. Usages will need to remove any
lifetime parameters:
```rust
// BEFORE
fn execute<'env, F: IntoFunction<'env, Marker>, Marker>(f: F) {/* ... */}
// AFTER
fn execute<F: IntoFunction<Marker>, Marker>(f: F) {/* ... */}
```
### `IntoReturn`
`IntoReturn::into_return` now has a where clause. Any manual
implementors will need to add this where clause to their implementation.
Currently, volumetric fog is global and affects the entire scene
uniformly. This is inadequate for many use cases, such as local smoke
effects. To address this problem, this commit introduces *fog volumes*,
which are axis-aligned bounding boxes (AABBs) that specify fog
parameters inside their boundaries. Such volumes can also specify a
*density texture*, a 3D texture of voxels that specifies the density of
the fog at each point.
To create a fog volume, add a `FogVolume` component to an entity (which
is included in the new `FogVolumeBundle` convenience bundle). Like light
probes, a fog volume is conceptually a 1×1×1 cube centered on the
origin; a transform can be used to position and resize this region. Many
of the fields on the existing `VolumetricFogSettings` have migrated to
the new `FogVolume` component. `VolumetricFogSettings` on a camera is
still needed to enable volumetric fog. However, by itself
`VolumetricFogSettings` is no longer sufficient to enable volumetric
fog; a `FogVolume` must be present. Applications that wish to retain the
old global fog behavior can simply surround the scene with a large fog
volume.
By way of implementation, this commit converts the volumetric fog shader
from a full-screen shader to one applied to a mesh. The strategy is
different depending on whether the camera is inside or outside the fog
volume. If the camera is inside the fog volume, the mesh is simply a
plane scaled to the viewport, effectively falling back to a full-screen
pass. If the camera is outside the fog volume, the mesh is a cube
transformed to coincide with the boundaries of the fog volume's AABB.
Importantly, in the latter case, only the front faces of the cuboid are
rendered. Instead of treating the boundaries of the fog as a sphere
centered on the camera position, as we did prior to this patch, we
raytrace the far planes of the AABB to determine the portion of each ray
contained within the fog volume. We then raymarch in shadow map space as
usual. If a density texture is present, we modulate the fixed density
value with the trilinearly-interpolated value from that texture.
Furthermore, this patch introduces optional jitter to fog volumes,
intended for use with TAA. This modifies the position of the ray from
frame to frame using interleaved gradient noise, in order to reduce
aliasing artifacts. Many implementations of volumetric fog in games use
this technique. Note that this patch makes no attempt to write a motion
vector; this is because when a view ray intersects multiple voxels
there's no single direction of motion. Consequently, fog volumes can
have ghosting artifacts, but because fog is "ghostly" by its nature,
these artifacts are less objectionable than they would be for opaque
objects.
A new example, `fog_volumes`, has been added. It demonstrates a single
fog volume containing a voxelized representation of the Stanford bunny.
The existing `volumetric_fog` example has been updated to use the new
local volumetrics API.
## Changelog
### Added
* Local `FogVolume`s are now supported, to localize fog to specific
regions. They can optionally have 3D density voxel textures for precise
control over the distribution of the fog.
### Changed
* `VolumetricFogSettings` on a camera no longer enables volumetric fog;
instead, it simply enables the processing of `FogVolume`s within the
scene.
## Migration Guide
* A `FogVolume` is now necessary in order to enable volumetric fog, in
addition to `VolumetricFogSettings` on the camera. Existing uses of
volumetric fog can be migrated by placing a large `FogVolume`
surrounding the scene.
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: François Mockers <mockersf@gmail.com>
# Objective
The borders example is separate from the rounded borders example. If you
find the borders example, you may miss the rounded borders example.
## Solution
Merge the examples in a basic way, since there is enough room to show
all options at the same time.
I also considered renaming the borders and rounded borders examples so
that they would be located next to each other in repo and UI, but it
felt like having a singular example was better.
## Testing
```
cargo run --example borders
```
---
## Showcase
The merged example looks like this:
# Objective
```rust
// Currently:
builder.add_after::<FooPlugin, _>(BarPlugin);
// After this PR:
builder.add_after::<FooPlugin>(BarPlugin);
```
This removes some weirdness and better parallels the rest of the
`PluginGroupBuilder` API.
## Solution
Define a helper method `type_id_of_val` to use in `.add_before` and
`.add_after` instead of `TypeId::of::<T>` (which requires the plugin
type to be nameable, preventing `impl Plugin` from being used).
## Testing
Ran `cargo run -p ci lints` successfully.
## Migration Guide
Removed second generic from `PluginGroupBuilder` methods: `add_before`
and `add_after`.
```rust
// Before:
DefaultPlugins
.build()
.add_before::<WindowPlugin, _>(FooPlugin)
.add_after::<WindowPlugin, _>(BarPlugin)
// After:
DefaultPlugins
.build()
.add_before::<WindowPlugin>(FooPlugin)
.add_after::<WindowPlugin>(BarPlugin)
```
---------
Co-authored-by: BD103 <59022059+BD103@users.noreply.github.com>
# Objective
- Fixes https://github.com/bevyengine/bevy/issues/14036
## Solution
- Add a view space transformation for the skybox
## Testing
- I have tested the newly added `transform` field using the `skybox`
example.
```
diff --git a/examples/3d/skybox.rs b/examples/3d/skybox.rs
index beaf5b268..d16cbe988 100644
--- a/examples/3d/skybox.rs
+++ b/examples/3d/skybox.rs
@@ -81,6 +81,7 @@ fn setup(mut commands: Commands, asset_server: Res<AssetServer>) {
Skybox {
image: skybox_handle.clone(),
brightness: 1000.0,
+ rotation: Quat::from_rotation_x(PI * -0.5),
},
));
```
<img width="1280" alt="image"
src="https://github.com/bevyengine/bevy/assets/6300263/1230a608-58ea-492d-a811-90c54c3b43ef">
## Migration Guide
- Since we have added a new filed to the Skybox struct, users will need
to include `..Default::default()` or some rotation value in their
initialization code.
# Objective
Implement FromIterator/IntoIterator for dynamic types where missing
Note:
- can't impl `IntoIterator` for `&Array` & co because of orphan rules
- `into_iter().collect()` is a no-op for `Vec`s because of
specialization
---
## Migration Guide
- Change `DynamicArray::from_vec` to `DynamicArray::from_iter`
# Objective
Fixes#14202
## Solution
Add `on_replaced` component hook and `OnReplaced` observer trigger
## Testing
- Did you test these changes? If so, how?
- Updated & added unit tests
---
## Changelog
- Added new `on_replaced` component hook and `OnReplaced` observer
trigger for performing cleanup on component values when they are
overwritten with `.insert()`
# Objective
- Using bincode to deserialize binary into a MeshletMesh is expensive
(~77ms for a 5mb file).
## Solution
- Write a custom deserializer using bytemuck's Pod types and slice
casting.
- Total asset load time has gone from ~102ms to ~12ms.
- Change some types I never meant to be public to private and other misc
cleanup.
## Testing
- Ran the meshlet example and added timing spans to the asset loader.
---
## Changelog
- Improved `MeshletMesh` loading speed
- The `MeshletMesh` disk format has changed, and
`MESHLET_MESH_ASSET_VERSION` has been bumped
- `MeshletMesh` fields are now private
- Renamed `MeshletMeshSaverLoad` to `MeshletMeshSaverLoader`
- The `Meshlet`, `MeshletBoundingSpheres`, and `MeshletBoundingSphere`
types are now private
- Removed `MeshletMeshSaveOrLoadError::SerializationOrDeserialization`
- Added `MeshletMeshSaveOrLoadError::WrongFileType`
## Migration Guide
- Regenerate your `MeshletMesh` assets, as the disk format has changed,
and `MESHLET_MESH_ASSET_VERSION` has been bumped
- `MeshletMesh` fields are now private
- `MeshletMeshSaverLoad` is now named `MeshletMeshSaverLoader`
- The `Meshlet`, `MeshletBoundingSpheres`, and `MeshletBoundingSphere`
types are now private
- `MeshletMeshSaveOrLoadError::SerializationOrDeserialization` has been
removed
- Added `MeshletMeshSaveOrLoadError::WrongFileType`, match on this
variant if you match on `MeshletMeshSaveOrLoadError`
# Objective
Type data is a **super** useful tool to know about when working with
reflection. However, most users don't fully understand how it works or
that you can use it for more than just object-safe traits.
This is unfortunate because it can be surprisingly simple to manually
create your own type data.
We should have an example detailing how type works, how users can define
their own, and how thy can be used.
## Solution
Added a `type_data` example.
This example goes through all the major points about type data:
- Why we need them
- How they can be defined
- The two ways they can be registered
- A list of common/important type data provided by Bevy
I also thought it might be good to go over the `#[reflect_trait]` macro
as part of this example since it has all the other context, including
how to define type data in places where `#[reflect_trait]` won't work.
Because of this, I removed the `trait_reflection` example.
## Testing
You can run the example locally with the following command:
```
cargo run --example type_data
```
---
## Changelog
- Added the `type_data` example
- Removed the `trait_reflection` example
This commit creates a new built-in postprocessing shader that's designed
to hold miscellaneous postprocessing effects, and starts it off with
chromatic aberration. Possible future effects include vignette, film
grain, and lens distortion.
[Chromatic aberration] is a common postprocessing effect that simulates
lenses that fail to focus all colors of light to a single point. It's
often used for impact effects and/or horror games. This patch uses the
technique from *Inside* ([Gjøl & Svendsen 2016]), which allows the
developer to customize the particular color pattern to achieve different
effects. Unity HDRP uses the same technique, while Unreal has a
hard-wired fixed color pattern.
A new example, `post_processing`, has been added, in order to
demonstrate the technique. The existing `post_processing` shader has
been renamed to `custom_post_processing`, for clarity.
[Chromatic aberration]:
https://en.wikipedia.org/wiki/Chromatic_aberration
[Gjøl & Svendsen 2016]:
https://github.com/playdeadgames/publications/blob/master/INSIDE/rendering_inside_gdc2016.pdf
## Changelog
### Added
* Chromatic aberration is now available as a built-in postprocessing
effect. To use it, add `ChromaticAberration` to your camera.
# Objective
Add basic bubbling to observers, modeled off `bevy_eventlistener`.
## Solution
- Introduce a new `Traversal` trait for components which point to other
entities.
- Provide a default `TraverseNone: Traversal` component which cannot be
constructed.
- Implement `Traversal` for `Parent`.
- The `Event` trait now has an associated `Traversal` which defaults to
`TraverseNone`.
- Added a field `bubbling: &mut bool` to `Trigger` which can be used to
instruct the runner to bubble the event to the entity specified by the
event's traversal type.
- Added an associated constant `SHOULD_BUBBLE` to `Event` which
configures the default bubbling state.
- Added logic to wire this all up correctly.
Introducing the new associated information directly on `Event` (instead
of a new `BubblingEvent` trait) lets us dispatch both bubbling and
non-bubbling events through the same api.
## Testing
I have added several unit tests to cover the common bugs I identified
during development. Running the unit tests should be enough to validate
correctness. The changes effect unsafe portions of the code, but should
not change any of the safety assertions.
## Changelog
Observers can now bubble up the entity hierarchy! To create a bubbling
event, change your `Derive(Event)` to something like the following:
```rust
#[derive(Component)]
struct MyEvent;
impl Event for MyEvent {
type Traverse = Parent; // This event will propagate up from child to parent.
const AUTO_PROPAGATE: bool = true; // This event will propagate by default.
}
```
You can dispatch a bubbling event using the normal
`world.trigger_targets(MyEvent, entity)`.
Halting an event mid-bubble can be done using
`trigger.propagate(false)`. Events with `AUTO_PROPAGATE = false` will
not propagate by default, but you can enable it using
`trigger.propagate(true)`.
If there are multiple observers attached to a target, they will all be
triggered by bubbling. They all share a bubbling state, which can be
accessed mutably using `trigger.propagation_mut()` (`trigger.propagate`
is just sugar for this).
You can choose to implement `Traversal` for your own types, if you want
to bubble along a different structure than provided by `bevy_hierarchy`.
Implementers must be careful never to produce loops, because this will
cause bevy to hang.
## Migration Guide
+ Manual implementations of `Event` should add associated type `Traverse
= TraverseNone` and associated constant `AUTO_PROPAGATE = false`;
+ `Trigger::new` has new field `propagation: &mut Propagation` which
provides the bubbling state.
+ `ObserverRunner` now takes the same `&mut Propagation` as a final
parameter.
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: Torstein Grindvik <52322338+torsteingrindvik@users.noreply.github.com>
Co-authored-by: Carter Anderson <mcanders1@gmail.com>
# Objective
update the `load_gltf_extras.rs` example to the newest bevy api
## Solution
uses the new type-safe code for loading the scene #0 from the gltf
instead of a path suffix
## Testing
the example runs as expected
# Objective
- Moves the smooth_follow.rs into movement directory in examples
- Fixes#14241
## Solution
- Move the smooth_follow.rs to movement dir in examples.
_copy-pasted from my doc comment in the code_
# Objective
This example shows how to properly handle player input, advance a
physics simulation in a fixed timestep, and display the results.
The classic source for how and why this is done is Glenn Fiedler's
article [Fix Your
Timestep!](https://gafferongames.com/post/fix_your_timestep/).
## Motivation
The naive way of moving a player is to just update their position like
so:
```rust
transform.translation += velocity;
```
The issue here is that the player's movement speed will be tied to the
frame rate.
Faster machines will move the player faster, and slower machines will
move the player slower.
In fact, you can observe this today when running some old games that did
it this way on modern hardware!
The player will move at a breakneck pace.
The more sophisticated way is to update the player's position based on
the time that has passed:
```rust
transform.translation += velocity * time.delta_seconds();
```
This way, velocity represents a speed in units per second, and the
player will move at the same speed regardless of the frame rate.
However, this can still be problematic if the frame rate is very low or
very high. If the frame rate is very low, the player will move in large
jumps. This may lead to a player moving in such large jumps that they
pass through walls or other obstacles. In general, you cannot expect a
physics simulation to behave nicely with *any* delta time. Ideally, we
want to have some stability in what kinds of delta times we feed into
our physics simulation.
The solution is using a fixed timestep. This means that we advance the
physics simulation by a fixed amount at a time. If the real time that
passed between two frames is less than the fixed timestep, we simply
don't advance the physics simulation at all.
If it is more, we advance the physics simulation multiple times until we
catch up. You can read more about how Bevy implements this in the
documentation for
[`bevy::time::Fixed`](https://docs.rs/bevy/latest/bevy/time/struct.Fixed.html).
This leaves us with a last problem, however. If our physics simulation
may advance zero or multiple times per frame, there may be frames in
which the player's position did not need to be updated at all, and some
where it is updated by a large amount that resulted from running the
physics simulation multiple times. This is physically correct, but
visually jarring. Imagine a player moving in a straight line, but
depending on the frame rate, they may sometimes advance by a large
amount and sometimes not at all. Visually, we want the player to move
smoothly. This is why we need to separate the player's position in the
physics simulation from the player's position in the visual
representation. The visual representation can then be interpolated
smoothly based on the last and current actual player position in the
physics simulation.
This is a tradeoff: every visual frame is now slightly lagging behind
the actual physical frame, but in return, the player's movement will
appear smooth. There are other ways to compute the visual representation
of the player, such as extrapolation. See the [documentation of the
lightyear
crate](https://cbournhonesque.github.io/lightyear/book/concepts/advanced_replication/visual_interpolation.html)
for a nice overview of the different methods and their tradeoffs.
## Implementation
- The player's velocity is stored in a `Velocity` component. This is the
speed in units per second.
- The player's current position in the physics simulation is stored in a
`PhysicalTranslation` component.
- The player's previous position in the physics simulation is stored in
a `PreviousPhysicalTranslation` component.
- The player's visual representation is stored in Bevy's regular
`Transform` component.
- Every frame, we go through the following steps:
- Advance the physics simulation by one fixed timestep in the
`advance_physics` system.
This is run in the `FixedUpdate` schedule, which runs before the
`Update` schedule.
- Update the player's visual representation in the
`update_displayed_transform` system.
This interpolates between the player's previous and current position in
the physics simulation.
- Update the player's velocity based on the player's input in the
`handle_input` system.
## Relevant Issues
Related to #1259.
I'm also fairly sure I've seen an issue somewhere made by
@alice-i-cecile about showing how to move a character correctly in a
fixed timestep, but I cannot find it.
# Objective
- Often in games you will want to create chains of systems that modify
some event. For example, a chain of damage systems that handle a
DamageEvent and modify the underlying value before the health system
finally consumes the event. Right now this requires either:
* Using a component added to the entity
* Consuming and refiring events
Neither is ideal when really all we want to do is read the events value,
modify it, and write it back.
## Solution
- Create an EventMutator class similar to EventReader but with ResMut<T>
and iterators that return &mut so that events can be mutated.
## Testing
- I replicated all the existing tests for EventReader to make sure
behavior was the same (I believe) and added a number of tests specific
to testing that 1) events can actually be mutated, and that 2)
EventReader sees changes from EventMutator for events it hasn't already
seen.
## Migration Guide
Users currently using `ManualEventReader` should use `EventCursor`
instead. `ManualEventReader` will be removed in Bevy 0.16. Additionally,
`Events::get_reader` has been replaced by `Events::get_cursor`.
Users currently directly accessing the `Events` resource for mutation
should move to `EventMutator` if possible.
---------
Co-authored-by: poopy <gonesbird@gmail.com>
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
# Objective
Fixes https://github.com/bevyengine/bevy/issues/13972
## Solution
Added 3 new attributes to the `Component` macro.
## Testing
Added `component_hook_order_spawn_despawn_with_macro_hooks`, that makes
the same as `component_hook_order_spawn_despawn` but uses a struct, that
defines it's hooks with the `Component` macro.
---
---------
Co-authored-by: Gino Valente <49806985+MrGVSV@users.noreply.github.com>
# Replace ab_glyph with the more capable cosmic-text
Fixes#7616.
Cosmic-text is a more mature text-rendering library that handles scripts
and ligatures better than ab_glyph, it can also handle system fonts
which can be implemented in bevy in the future
Rebase of https://github.com/bevyengine/bevy/pull/8808
## Changelog
Replaces text renderer ab_glyph with cosmic-text
The definition of the font size has changed with the migration to cosmic
text. The behavior is now consistent with other platforms (e.g. the
web), where the font size in pixels measures the height of the font (the
distance between the top of the highest ascender and the bottom of the
lowest descender). Font sizes in your app need to be rescaled to
approximately 1.2x smaller; for example, if you were using a font size
of 60.0, you should now use a font size of 50.0.
## Migration guide
- `Text2dBounds` has been replaced with `TextBounds`, and it now accepts
`Option`s to the bounds, instead of using `f32::INFINITY` to inidicate
lack of bounds
- Textsizes should be changed, dividing the current size with 1.2 will
result in the same size as before.
- `TextSettings` struct is removed
- Feature `subpixel_alignment` has been removed since cosmic-text
already does this automatically
- TextBundles and things rendering texts requires the `CosmicBuffer`
Component on them as well
## Suggested followups:
- TextPipeline: reconstruct byte indices for keeping track of eventual
cursors in text input
- TextPipeline: (future work) split text entities into section entities
- TextPipeline: (future work) text editing
- Support line height as an option. Unitless `1.2` is the default used
in browsers (1.2x font size).
- Support System Fonts and font families
- Example showing of animated text styles. Eg. throbbing hyperlinks
---------
Co-authored-by: tigregalis <anak.harimau@gmail.com>
Co-authored-by: Nico Burns <nico@nicoburns.com>
Co-authored-by: sam edelsten <samedelsten1@gmail.com>
Co-authored-by: Dimchikkk <velo.app1@gmail.com>
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: Rob Parrett <robparrett@gmail.com>
# Objective
Fixes#14120
`ui_texture_slice` and `ui_texture_atlas_slice` were working as
intended, so undo the changes.
## Solution
Partially revert https://github.com/bevyengine/bevy/pull/14115 for
`ui_texture_slice` and `ui_texture_atlas_slice`.
## Testing
Ran those two examples, confirmed the border color is the thing that
changes when buttons are hovered.
# Objective
The `AssetReader` trait allows customizing the behavior of fetching
bytes for an `AssetPath`, and expects implementors to return `dyn
AsyncRead + AsyncSeek`. This gives implementors of `AssetLoader` great
flexibility to tightly integrate their asset loading behavior with the
asynchronous task system.
However, almost all implementors of `AssetLoader` don't use the async
functionality at all, and just call `AsyncReadExt::read_to_end(&mut
Vec<u8>)`. This is incredibly inefficient, as this method repeatedly
calls `poll_read` on the trait object, filling the vector 32 bytes at a
time. At my work we have assets that are hundreds of megabytes which
makes this a meaningful overhead.
## Solution
Turn the `Reader` type alias into an actual trait, with a provided
method `read_to_end`. This provided method should be more efficient than
the existing extension method, as the compiler will know the underlying
type of `Reader` when generating this function, which removes the
repeated dynamic dispatches and allows the compiler to make further
optimizations after inlining. Individual implementors are able to
override the provided implementation -- for simple asset readers that
just copy bytes from one buffer to another, this allows removing a large
amount of overhead from the provided implementation.
Now that `Reader` is an actual trait, I also improved the ergonomics for
implementing `AssetReader`. Currently, implementors are expected to box
their reader and return it as a trait object, which adds unnecessary
boilerplate to implementations. This PR changes that trait method to
return a pseudo trait alias, which allows implementors to return `impl
Reader` instead of `Box<dyn Reader>`. Now, the boilerplate for boxing
occurs in `ErasedAssetReader`.
## Testing
I made identical changes to my company's fork of bevy. Our app, which
makes heavy use of `read_to_end` for asset loading, still worked
properly after this. I am not aware if we have a more systematic way of
testing asset loading for correctness.
---
## Migration Guide
The trait method `bevy_asset::io::AssetReader::read` (and `read_meta`)
now return an opaque type instead of a boxed trait object. Implementors
of these methods should change the type signatures appropriately
```rust
impl AssetReader for MyReader {
// Before
async fn read<'a>(&'a self, path: &'a Path) -> Result<Box<Reader<'a>>, AssetReaderError> {
let reader = // construct a reader
Box::new(reader) as Box<Reader<'a>>
}
// After
async fn read<'a>(&'a self, path: &'a Path) -> Result<impl Reader + 'a, AssetReaderError> {
// create a reader
}
}
```
`bevy::asset::io::Reader` is now a trait, rather than a type alias for a
trait object. Implementors of `AssetLoader::load` will need to adjust
the method signature accordingly
```rust
impl AssetLoader for MyLoader {
async fn load<'a>(
&'a self,
// Before:
reader: &'a mut bevy::asset::io::Reader,
// After:
reader: &'a mut dyn bevy::asset::io::Reader,
_: &'a Self::Settings,
load_context: &'a mut LoadContext<'_>,
) -> Result<Self::Asset, Self::Error> {
}
```
Additionally, implementors of `AssetReader` that return a type
implementing `futures_io::AsyncRead` and `AsyncSeek` might need to
explicitly implement `bevy::asset::io::Reader` for that type.
```rust
impl bevy::asset::io::Reader for MyAsyncReadAndSeek {}
```
# Objective
- Add the `AccumulatedMouseMotion` and `AccumulatedMouseScroll`
resources to make it simpler to track mouse motion/scroll changes
- Closes#13915
## Solution
- Created two resources, `AccumulatedMouseMotion` and
`AccumulatedMouseScroll`, and a method that tracks the `MouseMotion` and
`MouseWheel` events and accumulates their deltas every frame.
- Also modified the mouse input example to show how to use the
resources.
## Testing
- Tested the changes by modifying an existing example to use the newly
added resources, and moving/scrolling my trackpad around a ton.
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: Gino Valente <49806985+MrGVSV@users.noreply.github.com>
# Objective
We're able to reflect types sooooooo... why not functions?
The goal of this PR is to make functions callable within a dynamic
context, where type information is not readily available at compile
time.
For example, if we have a function:
```rust
fn add(left: i32, right: i32) -> i32 {
left + right
}
```
And two `Reflect` values we've already validated are `i32` types:
```rust
let left: Box<dyn Reflect> = Box::new(2_i32);
let right: Box<dyn Reflect> = Box::new(2_i32);
```
We should be able to call `add` with these values:
```rust
// ?????
let result: Box<dyn Reflect> = add.call_dynamic(left, right);
```
And ideally this wouldn't just work for functions, but methods and
closures too!
Right now, users have two options:
1. Manually parse the reflected data and call the function themselves
2. Rely on registered type data to handle the conversions for them
For a small function like `add`, this isn't too bad. But what about for
more complex functions? What about for many functions?
At worst, this process is error-prone. At best, it's simply tedious.
And this is assuming we know the function at compile time. What if we
want to accept a function dynamically and call it with our own
arguments?
It would be much nicer if `bevy_reflect` could alleviate some of the
problems here.
## Solution
Added function reflection!
This adds a `DynamicFunction` type to wrap a function dynamically. This
can be called with an `ArgList`, which is a dynamic list of
`Reflect`-containing `Arg` arguments. It returns a `FunctionResult`
which indicates whether or not the function call succeeded, returning a
`Reflect`-containing `Return` type if it did succeed.
Many functions can be converted into this `DynamicFunction` type thanks
to the `IntoFunction` trait.
Taking our previous `add` example, this might look something like
(explicit types added for readability):
```rust
fn add(left: i32, right: i32) -> i32 {
left + right
}
let mut function: DynamicFunction = add.into_function();
let args: ArgList = ArgList::new().push_owned(2_i32).push_owned(2_i32);
let result: Return = function.call(args).unwrap();
let value: Box<dyn Reflect> = result.unwrap_owned();
assert_eq!(value.take::<i32>().unwrap(), 4);
```
And it also works on closures:
```rust
let add = |left: i32, right: i32| left + right;
let mut function: DynamicFunction = add.into_function();
let args: ArgList = ArgList::new().push_owned(2_i32).push_owned(2_i32);
let result: Return = function.call(args).unwrap();
let value: Box<dyn Reflect> = result.unwrap_owned();
assert_eq!(value.take::<i32>().unwrap(), 4);
```
As well as methods:
```rust
#[derive(Reflect)]
struct Foo(i32);
impl Foo {
fn add(&mut self, value: i32) {
self.0 += value;
}
}
let mut foo = Foo(2);
let mut function: DynamicFunction = Foo::add.into_function();
let args: ArgList = ArgList::new().push_mut(&mut foo).push_owned(2_i32);
function.call(args).unwrap();
assert_eq!(foo.0, 4);
```
### Limitations
While this does cover many functions, it is far from a perfect system
and has quite a few limitations. Here are a few of the limitations when
using `IntoFunction`:
1. The lifetime of the return value is only tied to the lifetime of the
first argument (useful for methods). This means you can't have a
function like `(a: i32, b: &i32) -> &i32` without creating the
`DynamicFunction` manually.
2. Only 15 arguments are currently supported. If the first argument is a
(mutable) reference, this number increases to 16.
3. Manual implementations of `Reflect` will need to implement the new
`FromArg`, `GetOwnership`, and `IntoReturn` traits in order to be used
as arguments/return types.
And some limitations of `DynamicFunction` itself:
1. All arguments share the same lifetime, or rather, they will shrink to
the shortest lifetime.
2. Closures that capture their environment may need to have their
`DynamicFunction` dropped before accessing those variables again (there
is a `DynamicFunction::call_once` to make this a bit easier)
3. All arguments and return types must implement `Reflect`. While not a
big surprise coming from `bevy_reflect`, this implementation could
actually still work by swapping `Reflect` out with `Any`. Of course,
that makes working with the arguments and return values a bit harder.
4. Generic functions are not supported (unless they have been manually
monomorphized)
And general, reflection gotchas:
1. `&str` does not implement `Reflect`. Rather, `&'static str`
implements `Reflect` (the same is true for `&Path` and similar types).
This means that `&'static str` is considered an "owned" value for the
sake of generating arguments. Additionally, arguments and return types
containing `&str` will assume it's `&'static str`, which is almost never
the desired behavior. In these cases, the only solution (I believe) is
to use `&String` instead.
### Followup Work
This PR is the first of two PRs I intend to work on. The second PR will
aim to integrate this new function reflection system into the existing
reflection traits and `TypeInfo`. The goal would be to register and call
a reflected type's methods dynamically.
I chose not to do that in this PR since the diff is already quite large.
I also want the discussion for both PRs to be focused on their own
implementation.
Another followup I'd like to do is investigate allowing common container
types as a return type, such as `Option<&[mut] T>` and `Result<&[mut] T,
E>`. This would allow even more functions to opt into this system. I
chose to not include it in this one, though, for the same reasoning as
previously mentioned.
### Alternatives
One alternative I had considered was adding a macro to convert any
function into a reflection-based counterpart. The idea would be that a
struct that wraps the function would be created and users could specify
which arguments and return values should be `Reflect`. It could then be
called via a new `Function` trait.
I think that could still work, but it will be a fair bit more involved,
requiring some slightly more complex parsing. And it of course is a bit
more work for the user, since they need to create the type via macro
invocation.
It also makes registering these functions onto a type a bit more
complicated (depending on how it's implemented).
For now, I think this is a fairly simple, yet powerful solution that
provides the least amount of friction for users.
---
## Showcase
Bevy now adds support for storing and calling functions dynamically
using reflection!
```rust
// 1. Take a standard Rust function
fn add(left: i32, right: i32) -> i32 {
left + right
}
// 2. Convert it into a type-erased `DynamicFunction` using the `IntoFunction` trait
let mut function: DynamicFunction = add.into_function();
// 3. Define your arguments from reflected values
let args: ArgList = ArgList::new().push_owned(2_i32).push_owned(2_i32);
// 4. Call the function with your arguments
let result: Return = function.call(args).unwrap();
// 5. Extract the return value
let value: Box<dyn Reflect> = result.unwrap_owned();
assert_eq!(value.take::<i32>().unwrap(), 4);
```
## Changelog
#### TL;DR
- Added support for function reflection
- Added a new `Function Reflection` example:
ba727898f2/examples/reflection/function_reflection.rs (L1-L157)
#### Details
Added the following items:
- `ArgError` enum
- `ArgId` enum
- `ArgInfo` struct
- `ArgList` struct
- `Arg` enum
- `DynamicFunction` struct
- `FromArg` trait (derived with `derive(Reflect)`)
- `FunctionError` enum
- `FunctionInfo` struct
- `FunctionResult` alias
- `GetOwnership` trait (derived with `derive(Reflect)`)
- `IntoFunction` trait (with blanket implementation)
- `IntoReturn` trait (derived with `derive(Reflect)`)
- `Ownership` enum
- `ReturnInfo` struct
- `Return` enum
---------
Co-authored-by: Periwink <charlesbour@gmail.com>
# Objective
- Some people have asked how to do image masking in UI. It's pretty easy
to do using a `UiMaterial` assuming you know how to write shaders.
## Solution
- Update the ui_material example to show the bevy banner slowly being
revealed like a progress bar
## Notes
I'm not entirely sure if we want this or not. For people that would be
comfortable to use this for their own games they would probably have
already figured out how to do it and for people that aren't familiar
with shaders this isn't really enough to make an actual slider/progress
bar.
---------
Co-authored-by: François Mockers <francois.mockers@vleue.com>
As reported in #14004, many third-party plugins, such as Hanabi, enqueue
entities that don't have meshes into render phases. However, the
introduction of indirect mode added a dependency on mesh-specific data,
breaking this workflow. This is because GPU preprocessing requires that
the render phases manage indirect draw parameters, which don't apply to
objects that aren't meshes. The existing code skips over binned entities
that don't have indirect draw parameters, which causes the rendering to
be skipped for such objects.
To support this workflow, this commit adds a new field,
`non_mesh_items`, to `BinnedRenderPhase`. This field contains a simple
list of (bin key, entity) pairs. After drawing batchable and unbatchable
objects, the non-mesh items are drawn one after another. Bevy itself
doesn't enqueue any items into this list; it exists solely for the
application and/or plugins to use.
Additionally, this commit switches the asset ID in the standard bin keys
to be an untyped asset ID rather than that of a mesh. This allows more
flexibility, allowing bins to be keyed off any type of asset.
This patch adds a new example, `custom_phase_item`, which simultaneously
serves to demonstrate how to use this new feature and to act as a
regression test so this doesn't break again.
Fixes#14004.
## Changelog
### Added
* `BinnedRenderPhase` now contains a `non_mesh_items` field for plugins
to add custom items to.
# Objective
- #14017 changed how `UiImage` and `BackgroundColor` work
- one change was missed in example `color_grading`, another in the
mobile example
## Solution
- Change it in the examples
# Objective
In Bevy 0.13, `BackgroundColor` simply tinted the image of any
`UiImage`. This was confusing: in every other case (e.g. Text), this
added a solid square behind the element. #11165 changed this, but
removed `BackgroundColor` from `ImageBundle` to avoid confusion, since
the semantic meaning had changed.
However, this resulted in a serious UX downgrade / inconsistency, as
this behavior was no longer part of the bundle (unlike for `TextBundle`
or `NodeBundle`), leaving users with a relatively frustrating upgrade
path.
Additionally, adding both `BackgroundColor` and `UiImage` resulted in a
bizarre effect, where the background color was seemingly ignored as it
was covered by a solid white placeholder image.
Fixes#13969.
## Solution
Per @viridia's design:
> - if you don't specify a background color, it's transparent.
> - if you don't specify an image color, it's white (because it's a
multiplier).
> - if you don't specify an image, no image is drawn.
> - if you specify both a background color and an image color, they are
independent.
> - the background color is drawn behind the image (in whatever pixels
are transparent)
As laid out by @benfrankel, this involves:
1. Changing the default `UiImage` to use a transparent texture but a
pure white tint.
2. Adding `UiImage::solid_color` to quickly set placeholder images.
3. Changing the default `BorderColor` and `BackgroundColor` to
transparent.
4. Removing the default overrides for these values in the other assorted
UI bundles.
5. Adding `BackgroundColor` back to `ImageBundle` and `ButtonBundle`.
6. Adding a 1x1 `Image::transparent`, which can be accessed from
`Assets<Image>` via the `TRANSPARENT_IMAGE_HANDLE` constant.
Huge thanks to everyone who helped out with the design in the linked
issue and [the Discord
thread](https://discord.com/channels/691052431525675048/1255209923890118697/1255209999278280844):
this was very much a joint design.
@cart helped me figure out how to set the UiImage's default texture to a
transparent 1x1 image, which is a much nicer fix.
## Testing
I've checked the examples modified by this PR, and the `ui` example as
well just to be sure.
## Migration Guide
- `BackgroundColor` no longer tints the color of images in `ImageBundle`
or `ButtonBundle`. Set `UiImage::color` to tint images instead.
- The default texture for `UiImage` is now a transparent white square.
Use `UiImage::solid_color` to quickly draw debug images.
- The default value for `BackgroundColor` and `BorderColor` is now
transparent. Set the color to white manually to return to previous
behavior.
# Objective
Add example of an enum Component to ecs_guide.
Fixes https://github.com/bevyengine/bevy/issues/11344.
## Solution
Extended ecs_guide "game" to include an enum tracking whether a player
is on a "hot" or "cold" streak.
## Testing
Ran example manually.
cc @MrGVSV
# Objective
In a few examples, we're specifying a font or font size that is the same
as the current default value. Might as well use the default. That'll be
one less thing to worry about if we ever need to change the default font
size. (wink)
In a few others, we were using a value of `25.0` and it didn't seem like
it was different for an important reason, so I switched to the default
there too.
(There are a bunch of examples that use non-default font sizes for
various reasons. Not trying address them all here.)
# Objective
A couple issues with this example are evident from this screenshot of
the example showcase:
<img width="319" alt="image"
src="https://github.com/bevyengine/bevy/assets/200550/5325bb29-9576-4989-a5a3-a972c8bbf1af">
- The images are misaligned, closer to the right edge of the screen
- The example uses a custom window resolution with a different aspect
ratio from the default, which results in black bars
## Solution
- Use the default window size
- Adjust positions so that things are centered
This isn't really fixing a problem, but I also:
- Used the default font size and adjusted the text labels and gaps so
that everything still fits
Which is how I got here in the first place (one less font size to adjust
for the cosmic text PR).
## Before
<img width="1350" alt="Screenshot 2024-06-20 at 12 23 10 PM"
src="https://github.com/bevyengine/bevy/assets/200550/1c7cfcfe-7edc-4561-a4e7-9b3bc8f87f75">
## After
<img width="1280" alt="Screenshot 2024-06-20 at 12 23 30 PM"
src="https://github.com/bevyengine/bevy/assets/200550/abab8a46-4e11-4ee6-a407-ae3b8bf31975">
# Objective
The documentation for
[`Transform::align`](https://docs.rs/bevy/0.14.0-rc.3/bevy/transform/components/struct.Transform.html#method.align)
mentions a hypothetical ship model. Showing this concretely would be a
nice improvement over using a cube.
> For example, if a spaceship model has its nose pointing in the
X-direction in its own local coordinates and its dorsal fin pointing in
the Y-direction, then align(Dir3::X, v, Dir3::Y, w) will make the
spaceship’s nose point in the direction of v, while the dorsal fin does
its best to point in the direction w.
## Solution
This commit makes the ship less hypothetical by using a kenney ship
model in the example.
The local axes for the ship needed to change to accommodate the gltf, so
the hypothetical in the documentation and this example's local axes
don't necessarily match. Docs use `align(Dir3::X, v, Dir3::Y, w)` and
this example now uses `(Vec3::NEG_Z, *first, Vec3::X, *second)`.
I manually modified the `craft_speederD` Node's `translation` to be
0,0,0 in the gltf file, which means it now differs from kenney's
original model.
Original ship from: https://kenney.nl/assets/space-kit
## Testing
```
cargo run --example align
```
# Objective
Fixes#13920
## Solution
As described in the issue.
## Testing
Moved a custom transition plugin in example before any of the app-state
methods.
# Objective
[`StableInterpolate`](https://dev-docs.bevyengine.org/bevy/math/trait.StableInterpolate.html)
was introduced after this example was written (or more accurately, the
two PRs were merged on the same day and developed in parallel).
The example used `Vec3::lerp` where I believe it is now preferred to use
`smooth_nudge`.
## Solution
Its not entirely clear to me whether `StableInterpolate` should be
preferred in this scenario, although it seems likely. So I figured a PR
to make the change would either result in it being merged or denied with
a reason.
## Testing
```
cargo run --example 2d_top_down_camera
```
Co-authored-by: François Mockers <mockersf@gmail.com>
