# Objective
This PR implements part of the [Curve
RFC](https://github.com/bevyengine/rfcs/blob/main/rfcs/80-curve-trait.md).
See that document for motivation, objectives, etc.
## Solution
For purposes of reviewability, this PR excludes the entire part of the
RFC related to taking multiple samples, resampling, and interpolation
generally. (This means the entire `cores` submodule is also excluded.)
On the other hand, the entire `Interval` type and all of the functional
`Curve` adaptors are included.
## Testing
Test modules are included and can be run locally (but they are also
included in CI).
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Basically it's https://github.com/bevyengine/bevy/pull/13792 with the
bumped versions of `encase` and `hexasphere`.
---------
Co-authored-by: Robert Swain <robert.swain@gmail.com>
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
# Objective
Bevy's direction types have `new` and `new_unchecked` constructors, but
no unchecked variant for the `Dir2::from_xy` and `Dir3::from_xyz`
methods.
For me, this has several times lead to constructing directions like
this, in cases where the components of the direction are already known
to be normalized:
```rust
let normal = Dir2::new_unchecked(Vec2::new(-ray.direction.x.signum(), 0.0));
```
```rust
segment.direction =
Dir2::new_unchecked(Vec2::new(-segment.direction.x, segment.direction.y));
```
For consistency and ergonomics, it would be nice to have unchecked
variants of `Dir2::from_xy` and `Dir3::from_xyz`:
```rust
let normal = Dir2::from_xy_unchecked(-ray.direction.x.signum(), 0.0);
```
```rust
segment.direction = Dir2::from_xy_unchecked(-segment.direction.x, segment.direction.y);
```
## Solution
Add `Dir2::from_xy_unchecked` and `Dir3::from_xyz_unchecked`.
# Objective
Previously, this area of bevy_math used raw translation and rotations to
encode isometries, which did not exist earlier. The goal of this PR is
to make the codebase of bevy_math more harmonious by using actual
isometries (`Isometry2d`/`Isometry3d`) in these places instead — this
will hopefully make the interfaces more digestible for end-users, in
addition to facilitating conversions.
For instance, together with the addition of #14478, this means that a
bounding box for a collider with an isometric `Transform` can be
computed as
```rust
collider.aabb_3d(collider_transform.to_isometry())
```
instead of using manual destructuring.
## Solution
- The traits `Bounded2d` and `Bounded3d` now use `Isometry2d` and
`Isometry3d` (respectively) instead of `translation` and `rotation`
parameters; e.g.:
```rust
/// A trait with methods that return 3D bounding volumes for a shape.
pub trait Bounded3d {
/// Get an axis-aligned bounding box for the shape translated and
rotated by the given isometry.
fn aabb_3d(&self, isometry: Isometry3d) -> Aabb3d;
/// Get a bounding sphere for the shape translated and rotated by the
given isometry.
fn bounding_sphere(&self, isometry: Isometry3d) -> BoundingSphere;
}
```
- Similarly, the `from_point_cloud` constructors for axis-aligned
bounding boxes and bounding circles/spheres now take isometries instead
of separate `translation` and `rotation`; e.g.:
```rust
/// Computes the smallest [`Aabb3d`] containing the given set of points,
/// transformed by the rotation and translation of the given isometry.
///
/// # Panics
///
/// Panics if the given set of points is empty.
#[inline(always)]
pub fn from_point_cloud(
isometry: Isometry3d,
points: impl Iterator<Item = impl Into<Vec3A>>,
) -> Aabb3d { //... }
```
This has a couple additional results:
1. The end-user no longer interacts directly with `Into<Vec3A>` or
`Into<Rot2>` parameters; these conversions all happen earlier now,
inside the isometry types.
2. Similarly, almost all intermediate `Vec3 -> Vec3A` conversions have
been eliminated from the `Bounded3d` implementations for primitives.
This probably has some performance benefit, but I have not measured it
as of now.
## Testing
Existing unit tests help ensure that nothing has been broken in the
refactor.
---
## Migration Guide
The `Bounded2d` and `Bounded3d` traits now take `Isometry2d` and
`Isometry3d` parameters (respectively) instead of separate translation
and rotation arguments. Existing calls to `aabb_2d`, `bounding_circle`,
`aabb_3d`, and `bounding_sphere` will have to be changed to use
isometries instead. A straightforward conversion is to refactor just by
calling `Isometry2d/3d::new`, as follows:
```rust
// Old:
let aabb = my_shape.aabb_2d(my_translation, my_rotation);
// New:
let aabb = my_shape.aabb_2d(Isometry2d::new(my_translation, my_rotation));
```
However, if the old translation and rotation are 3d
translation/rotations originating from a `Transform` or
`GlobalTransform`, then `to_isometry` may be used instead. For example:
```rust
// Old:
let bounding_sphere = my_shape.bounding_sphere(shape_transform.translation, shape_transform.rotation);
// New:
let bounding_sphere = my_shape.bounding_sphere(shape_transform.to_isometry());
```
This discussion also applies to the `from_point_cloud` construction
method of `Aabb2d`/`BoundingCircle`/`Aabb3d`/`BoundingSphere`, which has
similarly been altered to use isometries.
# Objective
Previously, our cubic spline constructors would produce
`CubicCurve`/`RationalCurve` output with no data when they themselves
didn't hold enough control points to produce a well-formed curve.
Attempting to sample the resulting empty "curves" (e.g. by calling
`CubicCurve::position`) would crash the program (😓).
The objectives of this PR are:
1. Ensure that the curve output of `bevy_math`'s spline constructions
are never invalid as data.
2. Provide a type-level guarantee that `CubicCurve` and `RationalCurve`
actually function as curves.
## Solution
This has a few pieces. Firstly, the curve generator traits
`CubicGenerator`, `CyclicCubicGenerator`, and `RationalGenerator` are
now fallible — they have associated error types, and the
curve-generation functions are allowed to fail:
```rust
/// Implement this on cubic splines that can generate a cubic curve from their spline parameters.
pub trait CubicGenerator<P: VectorSpace> {
/// An error type indicating why construction might fail.
type Error;
/// Build a [`CubicCurve`] by computing the interpolation coefficients for each curve segment.
fn to_curve(&self) -> Result<CubicCurve<P>, Self::Error>;
}
```
All existing spline constructions use this together with errors that
indicate when they didn't have the right control data and provide curves
which have at least one segment whenever they return an `Ok` variant.
Next, `CubicCurve` and `RationalCurve` have been blessed with a
guarantee that their internal array of segments (`segments`) is never
empty. In particular, this field is no longer public, so that invalid
curves cannot be built using struct instantiation syntax. To compensate
for this shortfall for users (in particular library authors who might
want to implement their own generators), there is a new method
`from_segments` on these for constructing a curve from a list of
segments, failing if the list is empty:
```rust
/// Create a new curve from a collection of segments. If the collection of segments is empty,
/// a curve cannot be built and `None` will be returned instead.
pub fn from_segments(segments: impl Into<Vec<CubicSegment<P>>>) -> Option<Self> { //... }
```
All existing methods on `CyclicCurve` and `CubicCurve` maintain the
invariant, so the direct construction of invalid values by users is
impossible.
## Testing
Run unit tests from `bevy_math::cubic_splines`. Additionally, run the
`cubic_splines` example and try to get it to crash using small numbers
of control points: it uses the fallible constructors directly, so if
invalid data is ever constructed, it is basically guaranteed to crash.
---
## Migration Guide
The `to_curve` method on Bevy's cubic splines is now fallible (returning
a `Result`), meaning that any existing calls will need to be updated by
handling the possibility of an error variant.
Similarly, any custom implementation of `CubicGenerator` or
`RationalGenerator` will need to be amended to include an `Error` type
and be made fallible itself.
Finally, the fields of `CubicCurve` and `RationalCurve` are now private,
so any direct constructions of these structs from segments will need to
be replaced with the new `CubicCurve::from_segments` and
`RationalCurve::from_segments` methods.
---
## Design
The main thing to justify here is the choice for the curve internals to
remain the same. After all, if they were able to cause crashes in the
first place, it's worth wondering why safeguards weren't put in place on
the types themselves to prevent that.
My view on this is that the problem was really that the internals of
these methods implicitly relied on the assumption that the value they
were operating on was *actually a curve*, when this wasn't actually
guaranteed. Now, it's possible to make a bunch of small changes inside
the curve struct methods to account for that, but I think that's worse
than just guaranteeing that the data is valid upstream — sampling is
about as hot a code path as we're going to get in this area, and hitting
an additional branch every time it happens just to check that the struct
contains valid data is probably a waste of resources.
Another way of phrasing this is that even if we're only interested in
solving the crashes, the curve's validity needs to be checked at some
point, and it's almost certainly better to do this once at the point of
construction than every time the curve is sampled.
In cases where the control data is supplied dynamically, users would
already have to deal with empty curve outputs basically not working.
Anecdotally, I ran into this while writing the `cubic_splines` example,
and I think the diff illustrates the improvement pretty nicely — the
code no longer has to anticipate whether the output will be good or not;
it just has to handle the `Result`.
The cost of all this, of course, is that we have to guarantee that the
new invariant is actually maintained whenever we extend the API.
However, for the most part, I don't expect users to want to do much
surgery on the internals of their curves anyway.
# 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.
Reference to #14299.
# Objective
- Ensuring consistent practice of instantiating 3D primitive shapes in
Bevy.
## Solution
- Add `new` method, containing `radius` and `height` arguments, to Cone
3D primitive shape.
## Testing
- Instantiated cone using same values (radius is `2.` and height is
`5.`), using the current method and the added `new` method.
- Basic setup of Bevy Default Plugins and `3DCameraBundle`.
---
## Showcase
<details>
<summary>Click to view showcase</summary>
```rust
use bevy::prelude::*;
fn main() {
App::new()
.add_plugins(DefaultPlugins)
.add_systems(Startup, setup)
.run();
}
fn setup(
mut commands: Commands,
mut meshes: ResMut<Assets<Mesh>>,
mut materials: ResMut<Assets<StandardMaterial>>,
) {
let new_cone = meshes.add(Cone::new(2., 5.));
commands.spawn(PbrBundle {
mesh: new_cone,
..default()
});
let old_cone = meshes.add(Cone {
radius: 2.,
height: 5.,
});
commands.spawn(PbrBundle {
mesh: old_cone,
material: materials.add(Color::WHITE),
transform: Transform::from_xyz(10., 0., 0.),
..default()
});
commands.spawn(Camera3dBundle {
transform: Transform::from_xyz(20., 20., 20.).looking_at(Vec3::ZERO, Dir3::Y),
..default()
});
}
```
</details>
- Pink Cone is created using the `new` method.
- Black Cone is created using the existing method.
## Migration Guide
- Addition of `new` method to the 3D primitive Cone struct.
# Objective
`Annulus` is missing `Bounded2d` even though the implementation is
trivial.
## Solution
Implement `Bounded2d` for `Annulus`.
## Testing
There is a basic test to verify that the produced bounding volumes are
correct.
# Objective
Fixes#14308.
#14269 added the `Isometry2d` and `Isometry3d` types, but they don't
have usage examples or much documentation on what the types actually
represent or what they may be useful for.
In addition, their module is public and the types are not re-exported at
the crate root, unlike all the other core math types like Glam's types,
direction types, and `Rot2`.
## Solution
Improve the documentation of `Isometry2d` and `Isometry3d`, explaining
what they represent and can be useful for, along with doc examples on
common high-level usage. I also made the way the types are exported
consistent with other core math types.
This does add some duplication, but I personally think having good docs
for this is valuable, and people are also less likely to look at the
module-level docs than type-level docs.
# Objective
The isometry types added in #14269 support transforming other isometries
and points, as well as computing the inverse of an isometry using
`inverse`.
However, transformations like `iso1.inverse() * iso2` and `iso.inverse()
* point` can be optimized for single-shot cases using custom methods
that avoid an extra rotation operation.
## Solution
Add `inverse_mul` and `inverse_transform_point` for `Isometry2d` and
`Isometry3d`. Note that these methods are only faster when the isometry
can't be reused for multiple transformations.
## Testing
All of the methods have a test, similarly to the existing transformation
operations.
# Objective
Creating isometry types with just a translation is a bit more verbose
than it needs to be for cases where you don't have an existing vector to
pass in.
```rust
let iso = Isometry3d::from_translation(Vec3::new(2.0, 1.0, -1.0));
```
This could be made more ergonomic with a method similar to
`Dir2::from_xy`, `Dir3::from_xyz`, and `Transform::from_xyz`:
```rust
let iso = Isometry3d::from_xyz(2.0, 1.0, -1.0);
```
## Solution
Add `Isometry2d::from_xy` and `Isometry3d::from_xyz`.
# Objective
Introduce isometry types for describing relative and absolute position
in mathematical contexts.
## Solution
For the time being, this is a very minimal implementation. This
implements the following faculties for two- and three-dimensional
isometry types:
- Identity transformations
- Creation from translations and/or rotations
- Inverses
- Multiplication (composition) of isometries with each other
- Application of isometries to points (as vectors)
- Conversion of isometries to affine transformations
There is obviously a lot more that could be added, so I erred on the
side of adding things that I knew would be useful, with the idea of
expanding this in the near future as needed.
(I also fixed some random doc problems in `bevy_math`.)
---
## Design
One point of interest here is the matter of if/when to use aligned
types. In the implementation of 3d isometries, I used `Vec3A` rather
than `Vec3` because it has no impact on size/alignment, but I'm still
not sure about that decision (although it is easily changed).
For 2d isometries — which are encoded by four floats — the idea of
shoving them into a single 128-bit buffer (`__m128` or whatever) sounds
kind of enticing, but it's more involved and would involve writing
unsafe code, so I didn't do that for now.
## Future work
- Expand the API to include shortcuts like `inverse_mul` and
`inverse_transform` for efficiency reasons.
- Include more convenience constructors and methods (e.g. `from_xy`,
`from_xyz`).
- Refactor `bevy_math::bounding` to use the isometry types.
- Add conversions to/from isometries for `Transform`/`GlobalTransform`
in `bevy_transform`.
# Objective
- Bevy currently has lot of invalid intra-doc links, let's fix them!
- Also make CI test them, to avoid future regressions.
- Helps with #1983 (but doesn't fix it, as there could still be explicit
links to docs.rs that are broken)
## Solution
- Make `cargo r -p ci -- doc-check` check fail on warnings (could also
be changed to just some specific lints)
- Manually fix all the warnings (note that in some cases it was unclear
to me what the fix should have been, I'll try to highlight them in a
self-review)
# Objective
With an unlucky denormalised quaternion (or just a regular very
denormalised quaternion), it's possible to obtain NaN values for AABB's
in shapes which rely on an AABB for a disk.
## Solution
Add an additional `.max(Vec3::ZERO)` clamp to get rid of negative values
arising due to numerical errors.
Fixup some unnecessary calculations and improve variable names in
relevant code, aiming for consistency.
## Discussion
These two (nontrivial) lines of code are repeated at least 5 times,
maybe they could be their own method.
# Objective
Allow random sampling from the surfaces of triangle meshes.
## Solution
This has two parts.
Firstly, rendering meshes can now yield their collections of triangles
through a method `Mesh::triangles`. This has signature
```rust
pub fn triangles(&self) -> Result<Vec<Triangle3d>, MeshTrianglesError> { //... }
```
and fails in a variety of cases — the most obvious of these is that the
mesh must have either the `TriangleList` or `TriangleStrip` topology,
and the others correspond to malformed vertex or triangle-index data.
With that in hand, we have the second piece, which is
`UniformMeshSampler`, which is a `Vec3`-valued
[distribution](https://docs.rs/rand/latest/rand/distributions/trait.Distribution.html)
that samples uniformly from collections of triangles. It caches the
triangles' distribution of areas so that after its initial setup,
sampling is allocation-free. It is constructed via
`UniformMeshSampler::try_new`, which looks like this:
```rust
pub fn try_new<T: Into<Vec<Triangle3d>>>(triangles: T) -> Result<Self, ZeroAreaMeshError> { //... }
```
It fails if the collection of triangles has zero area.
The sum of these parts means that you can sample random points from a
mesh as follows:
```rust
let triangles = my_mesh.triangles().unwrap();
let mut rng = StdRng::seed_from_u64(8765309);
let distribution = UniformMeshSampler::try_new(triangles).unwrap();
// 10000 random points from the surface of my_mesh:
let sample_points: Vec<Vec3> = distribution.sample_iter(&mut rng).take(10000).collect();
```
## Testing
Tested by instantiating meshes and sampling as demonstrated above.
---
## Changelog
- Added `Mesh::triangles` method to get a collection of triangles from a
mesh.
- Added `UniformMeshSampler` to `bevy_math::sampling`. This is a
distribution which allows random sampling over collections of triangles
(such as those provided through meshes).
---
## Discussion
### Design decisions
The main thing here was making sure to have a good separation between
the parts of this in `bevy_render` and in `bevy_math`. Getting the
triangles from a mesh seems like a reasonable step after adding
`Triangle3d` to `bevy_math`, so I decided to make all of the random
sampling operate at that level, with the fallible conversion to
triangles doing most of the work.
Notably, the sampler could be called something else that reflects that
its input is a collection of triangles, but if/when we add other kinds
of meshes to `bevy_math` (e.g. half-edge meshes), the fact that
`try_new` takes an `impl Into<Vec<Triangle3d>>` means that those meshes
just need to satisfy that trait bound in order to work immediately with
this sampling functionality. In that case, the result would just be
something like this:
```rust
let dist = UniformMeshSampler::try_new(mesh).unwrap();
```
I think this highlights that most of the friction is really just from
extracting data from `Mesh`.
It's maybe worth mentioning also that "collection of triangles"
(`Vec<Triangle3d>`) sits downstream of any other kind of triangle mesh,
since the topology connecting the triangles has been effectively erased,
which makes an `Into<Vec<Triangle3d>>` trait bound seem all the more
natural to me.
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
This is an attempt to address issue #13725, which was about the
geometric primitives in the bevy_math crate lacking some detail in the
docs.
# Objective
Fixes#13725
## Solution
Added details to the docstrings. Mostly this consisted of specifying
that the primitives are centered on the origin, or describing how
they're defined (e.g., a circle is the set of all points some distance
from the origin).
## Testing
No testing, since the only changes were to docs.
# Objective
- Primitives should not use poorly defined types like `usize`,
especially since they are serializable
## Solution
- Use `u32` instead of `usize`
- The generic array types do not need to be changed because this size is
not actually stored or serialized anywhere
---
## Migration Guide
- `RegularPolygon` now uses `u32` instead of `usize` for the number of
sides
i based the design on @mgi388 in the discussion about the issue.
i added the illustration in such a way that it shows up when you hover
your mouse over the type, i hope this is what was meant by the issue
no unit tests were added bc obviously
Fixes#13664
# Objective
Partially address #13408
Rework of #13613
Unify the very nice forms of interpolation specifically present in
`bevy_math` under a shared trait upon which further behavior can be
based.
The ideas in this PR were prompted by [Lerp smoothing is broken by Freya
Holmer](https://www.youtube.com/watch?v=LSNQuFEDOyQ).
## Solution
There is a new trait `StableInterpolate` in `bevy_math::common_traits`
which enshrines a quite-specific notion of interpolation with a lot of
guarantees:
```rust
/// A type with a natural interpolation that provides strong subdivision guarantees.
///
/// Although the only required method is `interpolate_stable`, many things are expected of it:
///
/// 1. The notion of interpolation should follow naturally from the semantics of the type, so
/// that inferring the interpolation mode from the type alone is sensible.
///
/// 2. The interpolation recovers something equivalent to the starting value at `t = 0.0`
/// and likewise with the ending value at `t = 1.0`.
///
/// 3. Importantly, the interpolation must be *subdivision-stable*: for any interpolation curve
/// between two (unnamed) values and any parameter-value pairs `(t0, p)` and `(t1, q)`, the
/// interpolation curve between `p` and `q` must be the *linear* reparametrization of the original
/// interpolation curve restricted to the interval `[t0, t1]`.
///
/// The last of these conditions is very strong and indicates something like constant speed. It
/// is called "subdivision stability" because it guarantees that breaking up the interpolation
/// into segments and joining them back together has no effect.
///
/// Here is a diagram depicting it:
/// ```text
/// top curve = u.interpolate_stable(v, t)
///
/// t0 => p t1 => q
/// |-------------|---------|-------------|
/// 0 => u / \ 1 => v
/// / \
/// / \
/// / linear \
/// / reparametrization \
/// / t = t0 * (1 - s) + t1 * s \
/// / \
/// |-------------------------------------|
/// 0 => p 1 => q
///
/// bottom curve = p.interpolate_stable(q, s)
/// ```
///
/// Note that some common forms of interpolation do not satisfy this criterion. For example,
/// [`Quat::lerp`] and [`Rot2::nlerp`] are not subdivision-stable.
///
/// Furthermore, this is not to be used as a general trait for abstract interpolation.
/// Consumers rely on the strong guarantees in order for behavior based on this trait to be
/// well-behaved.
///
/// [`Quat::lerp`]: crate::Quat::lerp
/// [`Rot2::nlerp`]: crate::Rot2::nlerp
pub trait StableInterpolate: Clone {
/// Interpolate between this value and the `other` given value using the parameter `t`.
/// Note that the parameter `t` is not necessarily clamped to lie between `0` and `1`.
/// When `t = 0.0`, `self` is recovered, while `other` is recovered at `t = 1.0`,
/// with intermediate values lying between the two.
fn interpolate_stable(&self, other: &Self, t: f32) -> Self;
}
```
This trait has a blanket implementation over `NormedVectorSpace`, where
`lerp` is used, along with implementations for `Rot2`, `Quat`, and the
direction types using variants of `slerp`. Other areas may choose to
implement this trait in order to hook into its functionality, but the
stringent requirements must actually be met.
This trait bears no direct relationship with `bevy_animation`'s
`Animatable` trait, although they may choose to use `interpolate_stable`
in their trait implementations if they wish, as both traits involve
type-inferred interpolations of the same kind. `StableInterpolate` is
not a supertrait of `Animatable` for a couple reasons:
1. Notions of interpolation in animation are generally going to be much
more general than those allowed under these constraints.
2. Laying out these generalized interpolation notions is the domain of
`bevy_animation` rather than of `bevy_math`. (Consider also that
inferring interpolation from types is not universally desirable.)
Similarly, this is not implemented on `bevy_color`'s color types,
although their current mixing behavior does meet the conditions of the
trait.
As an aside, the subdivision-stability condition is of interest
specifically for the [Curve
RFC](https://github.com/bevyengine/rfcs/pull/80), where it also ensures
a kind of stability for subsampling.
Importantly, this trait ensures that the "smooth following" behavior
defined in this PR behaves predictably:
```rust
/// Smoothly nudge this value towards the `target` at a given decay rate. The `decay_rate`
/// parameter controls how fast the distance between `self` and `target` decays relative to
/// the units of `delta`; the intended usage is for `decay_rate` to generally remain fixed,
/// while `delta` is something like `delta_time` from an updating system. This produces a
/// smooth following of the target that is independent of framerate.
///
/// More specifically, when this is called repeatedly, the result is that the distance between
/// `self` and a fixed `target` attenuates exponentially, with the rate of this exponential
/// decay given by `decay_rate`.
///
/// For example, at `decay_rate = 0.0`, this has no effect.
/// At `decay_rate = f32::INFINITY`, `self` immediately snaps to `target`.
/// In general, higher rates mean that `self` moves more quickly towards `target`.
///
/// # Example
/// ```
/// # use bevy_math::{Vec3, StableInterpolate};
/// # let delta_time: f32 = 1.0 / 60.0;
/// let mut object_position: Vec3 = Vec3::ZERO;
/// let target_position: Vec3 = Vec3::new(2.0, 3.0, 5.0);
/// // Decay rate of ln(10) => after 1 second, remaining distance is 1/10th
/// let decay_rate = f32::ln(10.0);
/// // Calling this repeatedly will move `object_position` towards `target_position`:
/// object_position.smooth_nudge(&target_position, decay_rate, delta_time);
/// ```
fn smooth_nudge(&mut self, target: &Self, decay_rate: f32, delta: f32) {
self.interpolate_stable_assign(target, 1.0 - f32::exp(-decay_rate * delta));
}
```
As the documentation indicates, the intention is for this to be called
in game update systems, and `delta` would be something like
`Time::delta_seconds` in Bevy, allowing positions, orientations, and so
on to smoothly follow a target. A new example, `smooth_follow`,
demonstrates a basic implementation of this, with a sphere smoothly
following a sharply moving target:
https://github.com/bevyengine/bevy/assets/2975848/7124b28b-6361-47e3-acf7-d1578ebd0347
## Testing
Tested by running the example with various parameters.
# Objective
- `Rotation2d` is a very long name for a commonly used type.
## Solution
- Rename it to `Rot2` to match `glam`'s naming convention (e.g. `Vec2`)
I ran a poll, and `Rot2` was the favorite of the candidate names.
This is not actually a breaking change, since `Rotation2d` has not been
shipped yet.
---------
Co-authored-by: Alice Cecile <alice.i.cecil@gmail.com>
# Objective
- Due to coherency, it was previously not possible to implement
`Bounded3d` for `Extrusion<MyCustomPrimitive>`. This PR fixes that.
## Solution
- Added a new trait `BoundedExtrusion: Primitive2d + Bounded2d` which
provides functions for bounding boxes and spheres of extrusions of 2D
primitives.
- Changed all implementations of `Bounded3d for Extrusion<T>` to
`BoundedExtrusion for T`
- Implemented `Bounded3d for Extrusion<T: BoundedExtrusion>`
- Removed the `extrusion_bounding_box` and `extrusion_bounding_sphere`
functions and used them as default implementations in `BoundedExtrusion`
## Testing
- This PR does not change any implementations
---------
Co-authored-by: Lynn Büttgenbach <62256001+solis-lumine-vorago@users.noreply.github.com>
Co-authored-by: Matty <weatherleymatthew@gmail.com>
# Objective
Fill the gap in this functionality by implementing it for `Rotation2d`.
We have this already for `Quat` in addition to the direction types.
## Solution
`bevy_math::sampling` now contains an implementation of
`Distribution<Rotation2d>` for `Standard`, along with the associated
convenience implementation `Rotation2d: FromRng`, which allows syntax
like this for creating a random rotation:
```rust
// With `FromRng`:
let rotation = Rotation2d::from_rng(rng);
// With `rand::random`:
let another_rotation: Rotation2d = random();
// With `Rng::gen`:
let yet_another_rotation: Rotation2d = rng.gen();
```
I also cleaned up the documentation a little bit, seeding the `Rng`s
instead of building them from entropy, along with adding a handful of
inline directives.
# Objective
- Implement `Bounded3d` for some `Extrusion<T>`
- Provide methods to calculate `Aabb3d`s and `BoundingSphere`s for any
extrusion with a `Bounded2d` base shape
## Solution
- Implemented `Bounded3d` for all 2D `bevy_math` primitives with the
exception of `Plane2d`. As far as I can see, `Plane2d` is pretty much a
line? and I think it is very unintuitive to extrude a plane and get a
plane as a result.
- Add `extrusion_bounding_box` and `extrusion_bounding_sphere`. These
are not always used internally since there are faster methods for
specific extrusions. Both of them produce the optimal result within
precision limits though.
## Testing
- Bounds for extrusions are tested within the same module. All unique
implementations are tested.
- The correctness was validated visually aswell.
---------
Co-authored-by: Raphael Büttgenbach <62256001+solis-lumine-vorago@users.noreply.github.com>
Co-authored-by: IQuick 143 <IQuick143cz@gmail.com>
# Objective
Filling a hole in the API: Previously, there was no particularly
ergonomic way to go from, e.g., a pair of directions to the rotation
that links them.
## Solution
We introduce a small suite of API methods to `Dir2` to address this:
```rust
/// Get the rotation that rotates this direction to `other`.
pub fn rotation_to(self, other: Self) -> Rotation2d { //... }
/// Get the rotation that rotates `other` to this direction.
pub fn rotation_from(self, other: Self) -> Rotation2d { //... }
/// Get the rotation that rotates the X-axis to this direction.
pub fn rotation_from_x(self) -> Rotation2d { //... }
/// Get the rotation that rotates this direction to the X-axis.
pub fn rotation_to_x(self) -> Rotation2d { //... }
/// Get the rotation that rotates this direction to the Y-axis.
pub fn rotation_from_y(self) -> Rotation2d { //... }
/// Get the rotation that rotates the Y-axis to this direction.
pub fn rotation_to_y(self) -> Rotation2d { //... }
```
I also removed some language from the `Rotation2d` docs that is
misleading: the radian and angle conversion functions are already clear
about which angles they spit out, and `Rotation2d` itself doesn't have
any bounds on angles or anything.
# Objective
Implements #13647
## Solution
Created two enums, CompassQuadrant and CompassOctant inside compass.rs
with impls To and From Dir2. Used dir.to_angle().to_degrees() and
matched against the resulting value. I could have skipped to_degrees()
and matched against the radian value, but I thought this was more
readable. I'm probably wrong lol.
## Testing
Tested various dirs to compass variations.
---
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
# Objective
When working on `leafwing-input-manager` and in my games, I've found
these compass directions to be both clear and useful when attempting to
describe angles in 2 dimensions.
This was directly used when mapping gamepad inputs into 4-way movement
as a virtual dpad, and I expect other uses are common in games.
## Solution
- Add constants corresponding to the 4 cardinal and 4 semi-cardinal
directions.
## Testing
- I've validated the quadrants of each of the directions through
self-review.
---------
Co-authored-by: Alice Cecile <alice.i.cecil@gmail.com>
# Objective
Fixes#13535.
## Solution
I implemented `Reflect` for close to all math types now, except for some
types that it would cause issues (like some boxed types).
## Testing
- Everything seems to still build, will await CI though.
---
## Changelog
- Made close to all math types implement `Reflect`.
# Objective
Fixes#13456
## Solution
Moved `bevy_math`'s `Reflect` impls from `bevy_reflect` to `bevy_math`.
### Quick note
I accidentally used the same commit message while resolving a merge
conflict (first time I had to resolve a conflict). Sorry about that.
# Objective
- Create a new 2D primitive, Rhombus, also knows as "Diamond Shape"
- Simplify the creation and handling of isometric projections
- Extend Bevy's arsenal of 2D primitives
## Testing
- New unit tests created in bevy_math/ primitives and bev_math/ bounding
- Tested translations, rotations, wireframe, bounding sphere, aabb and
creation parameters
---------
Co-authored-by: Luís Figueiredo <luispcfigueiredo@tecnico.ulisboa.pt>
# Objective
The `ConicalFrustum` primitive should support meshing.
## Solution
Implement meshing for the `ConicalFrustum` primitive. The implementation
is nearly identical to `Cylinder` meshing, but supports two radii.
The default conical frustum is equivalent to a cone with a height of 1
and a radius of 0.5, truncated at half-height.
# Objective
Adopted #11748
## Solution
I've rebased on main to fix the merge conflicts. ~~Not quite ready to
merge yet~~
* Clippy is happy and the tests are passing, but...
* ~~The new shapes in `examples/2d/2d_shapes.rs` don't look right at
all~~ Never mind, looks like radians and degrees just got mixed up at
some point?
* I have updated one doc comment based on a review in the original PR.
---------
Co-authored-by: Alexis "spectria" Horizon <spectria.limina@gmail.com>
Co-authored-by: Alexis "spectria" Horizon <118812919+spectria-limina@users.noreply.github.com>
Co-authored-by: Joona Aalto <jondolf.dev@gmail.com>
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: Ben Harper <ben@tukom.org>
# Objective
Adopted #12659.
Resolved the merge conflicts on #12659;
* I merged the `triangle_tests` added by this PR and by #13020.
* I moved the [commented out
code](https://github.com/bevyengine/bevy/pull/12659#discussion_r1536640427)
from the original PR into a separate test with `#[should_panic]`.
---------
Co-authored-by: Vitor Falcao <vitorfhc@protonmail.com>
Co-authored-by: Ben Harper <ben@tukom.org>
I am unsure if this needs changing, so let me know if I need to change
anything else.
# Objective
Fixes#13461.
## Solution
I applied the changes as suggested in the issue, and updated the doc
comments accordingly
## Testing
I don't think this needs too much testing, but there are no `cargo test`
failures.
# Objective
Add random sampling for the `Annulus` primitive. This is part of ongoing
work to bring the various `bevy_math` primitives to feature parity.
## Solution
`Annulus` implements `ShapeSample`. Boundary sampling is implemented in
the obvious way, and interior sampling works exactly as in the
implementation for `Circle`, using the fact that the square of the
radius should be taken uniformly from between r^2 and R^2, where r and R
are the inner and outer radii respectively.
## Testing
I generated a bunch of random points and rendered them. Here's 1000
points on the interior of the default annulus:
<img width="1440" alt="Screenshot 2024-05-22 at 8 01 34 AM"
src="https://github.com/bevyengine/bevy/assets/2975848/19c31bb0-edba-477f-b247-2b12d854afae">
This looks kind of weird around the edges, but I verified that they're
all actually inside the annulus, so I assume it has to do with the fact
that the rendered circles have some radius.
Stolen from #12835.
# Objective
Sometimes you want to sample a whole bunch of points from a shape
instead of just one. You can write your own loop to do this, but it's
really more idiomatic to use a `rand`
[`Distribution`](https://docs.rs/rand/latest/rand/distributions/trait.Distribution.html)
with the `sample_iter` method. Distributions also support other useful
things like mapping, and they are suitable as generic items for
consumption by other APIs.
## Solution
`ShapeSample` has been given two new automatic trait methods,
`interior_dist` and `boundary_dist`. They both have similar signatures
(recall that `Output` is the output type for `ShapeSample`):
```rust
fn interior_dist(self) -> impl Distribution<Self::Output>
where Self: Sized { //... }
```
These have default implementations which are powered by wrapper structs
`InteriorOf` and `BoundaryOf` that actually implement `Distribution` —
the implementations effectively just call `ShapeSample::sample_interior`
and `ShapeSample::sample_boundary` on the contained type.
The upshot is that this allows iteration as follows:
```rust
// Get an iterator over boundary points of a rectangle:
let rectangle = Rectangle::new(1.0, 2.0);
let boundary_iter = rectangle.boundary_dist().sample_iter(rng);
// Collect a bunch of boundary points at once:
let boundary_pts: Vec<Vec2> = boundary_iter.take(1000).collect();
```
Alternatively, you can use `InteriorOf`/`BoundaryOf` explicitly to
similar effect:
```rust
let boundary_pts: Vec<Vec2> = BoundaryOf(rectangle).sample_iter(rng).take(1000).collect();
```
---
## Changelog
- Added `InteriorOf` and `BoundaryOf` distribution wrapper structs in
`bevy_math::sampling::shape_sampling`.
- Added `interior_dist` and `boundary_dist` automatic trait methods to
`ShapeSample`.
- Made `shape_sampling` module public with explanatory documentation.
---
## Discussion
### Design choices
The main point of interest here is just the choice of `impl
Distribution` instead of explicitly using `InteriorOf`/`BoundaryOf`
return types for `interior_dist` and `boundary_dist`. The reason for
this choice is that it allows future optimizations for repeated sampling
— for example, instead of just wrapping the base type,
`interior_dist`/`boundary_dist` could construct auxiliary data that is
held over between sampling operations.
# Objective
- Fixes#13092.
## Solution
- Renamed the `inset()` method in `Rect`, `IRect` and `URect` to
`inflate()`.
- Added `EMPTY` constants to all `Rect` variants, represented by corners
with the maximum numerical values for each kind.
---
## Migration Guide
- Replace `Rect::inset()`, `IRect::inset()` and `URect::inset()` calls
with `inflate()`.
# Objective
Add interior and boundary sampling for the `Tetrahedron` primitive. This
is part of ongoing work to bring the primitives to parity with each
other in terms of their capabilities.
## Solution
`Tetrahedron` implements the `ShapeSample` trait. To support this, there
is a new public method `Tetrahedron::faces` which gets the faces of a
tetrahedron as `Triangle3d`s. There are more sophisticated ideas for
getting the faces we might want to consider in the future (e.g.
adjusting according to the orientation), but this method gives the most
mathematically straightforward answer, giving the faces the orientation
induced by the tetrahedron itself.
# Objective
Fixes#13189
## Solution
To add the reflect impls I needed to make all the struct fields pub. I
don't think there's any harm for these types, but just a note for
review.
---------
Co-authored-by: Ben Harper <ben@tukom.org>
# Objective
Fixes#13332.
## Solution
The assertion `circumradius >= 0.0` to allow zero.
Are there any other shapes that need to be allowed to be constructed
with zero?
---------
Co-authored-by: François Mockers <francois.mockers@vleue.com>
# Objective
The `Cone` primitive should support meshing.
## Solution
Implement meshing for the `Cone` primitive. The default cone has a
height of 1 and a base radius of 0.5, and is centered at the origin.
An issue with cone meshes is that the tip does not really have a normal
that works, even with duplicated vertices. This PR uses only a single
vertex for the tip, with a normal of zero; this results in an "invalid"
normal that gets ignored by the fragment shader. This seems to be the
only approach we have for perfectly smooth cones. For discussion on the
topic, see #10298 and #5891.
Another thing to note is that the cone uses polar coordinates for the
UVs:
<img
src="https://github.com/bevyengine/bevy/assets/57632562/e101ded9-110a-4ac4-a98d-f1e4d740a24a"
alt="cone" width="400" />
This way, textures are applied as if looking at the cone from above:
<img
src="https://github.com/bevyengine/bevy/assets/57632562/8dea00f1-a283-4bc4-9676-91e8d4adb07a"
alt="texture" width="200" />
<img
src="https://github.com/bevyengine/bevy/assets/57632562/d9d1b5e6-a8ba-4690-b599-904dd85777a1"
alt="cone" width="200" />
# Objective
Sometimes it's nice to iterate over all the coordinate axes using
something like `Vec3::AXES`. This was not available for the
corresponding `Dir` types and now it is.
## Solution
We already have things like `Dir2::X`, `Dir3::Z` and so on, so I just
threw them in an array like the vector types do it. I also slightly
refactored the sphere gizmo code to use `Dir3::AXES` and operate on
directions instead of using `Dir3::new_unchecked`.
## Testing
I looked at the sphere in the `3d_gizmos` example and it seems to work,
so I assume I didn't break anything.
# Objective
- Adds a basic `Extrusion<T: Primitive2d>` shape, suggestion of #10572
## Solution
- Adds `Measured2d` and `Measured3d` traits for getting the
perimeter/area or area/volume of shapes. This allows implementing
`.volume()` and `.area()` for all extrusions `Extrusion<T: Primitive2d +
Measured2d>` within `bevy_math`
- All existing perimeter, area and volume implementations for primitves
have been moved into implementations of `Measured2d` and `Measured3d`
- Shapes should be extruded along the Z-axis since an extrusion of depth
`0.` should be equivalent in everything but name to the base shape
## Caviats
- I am not sure about the naming. `Extrusion<T>` could also be
`Prism<T>` and the `MeasuredNd` could also be something like
`MeasuredPrimitiveNd`. If you have any other suggestions, please fell
free to share them :)
## Future work
This PR adds a basic `Extrusion` shape and does not implement a lot of
things you might want it to. Some of the future possibilities include:
- [ ] bounding for extrusions
- [ ] making extrusions work with gizmos
- [ ] meshing
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
# Objective
- People have reported bounding volumes being slower than their existing
solution because it doesn't use SIMD aligned types.
## Solution
- Use `Vec3A` internally for bounding volumes, accepting `Into<Vec3A>`
wherever possible
- Change some code to make it more likely SIMD operations are used.
---
## Changelog
- Use `Vec3A` for 3D bounding volumes and raycasts
## Migration Guide
- 3D bounding volumes now use `Vec3A` types internally, return values
from methods on them now return `Vec3A` instead of `Vec3`
# Objective
Adds a few extra `#[doc(alias)]` entries to the
`bevy_math::primitives::WindingOrder` enum and its variants to improve
searchability.
## Solution
- Add "Orientation" for `WindingOrder` itself
- Add "AntiClockwise" for `CounterClockwise` variant
- Add "Collinear" for `Invalid` variant
These alternate terms seem to be quite common, especially in the
contexts of rendering and collision-detection.
Signed-off-by: Nullicorn <git@nullicorn.me>
# Objective
- General clenup of the primitives in `bevy_math`
- Add `eccentricity()` to `Ellipse`
## Solution
- Moved `Bounded3d` implementation for `Triangle3d` to the `bounded`
module
- Added `eccentricity()` to `Ellipse`
- `Ellipse::semi_major()` and `::semi_minor()` now accept `&self`
instead of `self`
- `Triangle3d::is_degenerate()` actually uses `f32::EPSILON` as
documented
- Added tests for `Triangle3d`-maths
---------
Co-authored-by: Joona Aalto <jondolf.dev@gmail.com>
Co-authored-by: Miles Silberling-Cook <nth.tensor@gmail.com>
# Objective
Augment Bevy's random sampling capabilities by providing good tools for
producing random directions and rotations.
## Solution
The `rand` crate has a natural tool for providing `Distribution`s whose
output is a type that doesn't require any additional data to sample
values — namely,
[`Standard`](https://docs.rs/rand/latest/rand/distributions/struct.Standard.html).
Here, our existing `ShapeSample` implementations have been put to good
use in providing these, resulting in patterns like the following:
```rust
// Using thread-local rng
let random_direction1: Dir3 = random();
// Using an explicit rng
let random_direction2: Dir3 = rng.gen();
// Using an explicit rng coupled explicitly with Standard
let random_directions: Vec<Dir3> = rng.sample_iter(Standard).take(5).collect();
```
Furthermore, we have introduced a trait `FromRng` which provides sugar
for `rng.gen()` that is more namespace-friendly (in this author's
opinion):
```rust
let random_direction = Dir3::from_rng(rng);
```
The types this has been implemented for are `Dir2`, `Dir3`, `Dir3A`, and
`Quat`. Notably, `Quat` uses `glam`'s implementation rather than an
in-house one, and as a result, `bevy_math`'s "rand" feature now enables
that of `glam`.
---
## Changelog
- Created `standard` submodule in `sampling` to hold implementations and
other items related to the `Standard` distribution.
- "rand" feature of `bevy_math` now enables that of `glam`.
---
## Discussion
From a quick glance at `Quat`'s distribution implementation in `glam`, I
am a bit suspicious, since it is simple and doesn't match any algorithm
that I came across in my research. I will do a little more digging as a
follow-up to this and see if it's actually uniform (maybe even using
those tools I wrote — what a thrill).
As an aside, I'd also like to say that I think
[`Distribution`](https://docs.rs/rand/latest/rand/distributions/trait.Distribution.html)
is really, really good. It integrates with distributions provided
externally (e.g. in `rand` itself and its extensions) along with doing a
good job of isolating the source of randomness, so that output can be
reliably reproduced if need be. Finally, `Distribution::sample_iter` is
quite good for ergonomically acquiring lots of random values. At one
point I found myself writing traits to describe random sampling and
essentially reinvented this one. I just think it's good, and I think
it's worth centralizing around to a significant extent.
# Objective
`AspectRatio` is a newtype of `f32`, so it can implement basic traits;
`Copy`, `Clone`, `Debug`, `PartialEq` and `PartialOrd`.
## Solution
Derive basic traits for `AspectRatio`.
# Objective
- #10572
There is no 3D primitive available for the common shape of a tetrahedron
(3-simplex).
## Solution
This PR introduces a new type to the existing math primitives:
- `Tetrahedron`: a polyhedron composed of four triangular faces, six
straight edges, and four vertices
---
## Changelog
### Added
- `Tetrahedron` primitive to the `bevy_math` crate
- `Tetrahedron` tests (`area`, `volume` methods)
- `impl_reflect!` declaration for `Tetrahedron` in the `bevy_reflect`
crate
# Objective
- There are several redundant imports in the tests and examples that are
not caught by CI because additional flags need to be passed.
## Solution
- Run `cargo check --workspace --tests` and `cargo check --workspace
--examples`, then fix all warnings.
- Add `test-check` to CI, which will be run in the check-compiles job.
This should catch future warnings for tests. Examples are already
checked, but I'm not yet sure why they weren't caught.
## Discussion
- Should the `--tests` and `--examples` flags be added to CI, so this is
caught in the future?
- If so, #12818 will need to be merged first. It was also a warning
raised by checking the examples, but I chose to split off into a
separate PR.
---------
Co-authored-by: François Mockers <francois.mockers@vleue.com>
- Fixes #[12762](https://github.com/bevyengine/bevy/issues/12762).
## Migration Guide
- `Quat` no longer implements `VectorSpace` as unit quaternions don't
actually form proper vector spaces. If you're absolutely certain that
what you're doing is correct, convert the `Quat` into a `Vec4` and
perform the operations before converting back.
# Objective
When I wrote #12747 I neglected to translate random samples from
triangles back to the point where they originated, so they would be
sampled near the origin instead of at the actual triangle location.
## Solution
Translate by the first vertex location so that the samples follow the
actual triangle.
# Objective
Previously, the `Point` trait, which abstracts all of the operations of
a real vector space, was sitting in the submodule of `bevy_math` for
cubic splines. However, the trait has broader applications than merely
cubic splines, and we should use it when possible to avoid code
duplication when performing vector operations.
## Solution
`Point` has been moved into a new submodule in `bevy_math` named
`common_traits`. Furthermore, it has been renamed to `VectorSpace`,
which is more descriptive, and an additional trait `NormedVectorSpace`
has been introduced to expand the API to cover situations involving
geometry in addition to algebra. Additionally, `VectorSpace` itself now
requires a `ZERO` constant and `Neg`. It also supports a `lerp` function
as an automatic trait method.
Here is what that looks like:
```rust
/// A type that supports the mathematical operations of a real vector space, irrespective of dimension.
/// In particular, this means that the implementing type supports:
/// - Scalar multiplication and division on the right by elements of `f32`
/// - Negation
/// - Addition and subtraction
/// - Zero
///
/// Within the limitations of floating point arithmetic, all the following are required to hold:
/// - (Associativity of addition) For all `u, v, w: Self`, `(u + v) + w == u + (v + w)`.
/// - (Commutativity of addition) For all `u, v: Self`, `u + v == v + u`.
/// - (Additive identity) For all `v: Self`, `v + Self::ZERO == v`.
/// - (Additive inverse) For all `v: Self`, `v - v == v + (-v) == Self::ZERO`.
/// - (Compatibility of multiplication) For all `a, b: f32`, `v: Self`, `v * (a * b) == (v * a) * b`.
/// - (Multiplicative identity) For all `v: Self`, `v * 1.0 == v`.
/// - (Distributivity for vector addition) For all `a: f32`, `u, v: Self`, `(u + v) * a == u * a + v * a`.
/// - (Distributivity for scalar addition) For all `a, b: f32`, `v: Self`, `v * (a + b) == v * a + v * b`.
///
/// Note that, because implementing types use floating point arithmetic, they are not required to actually
/// implement `PartialEq` or `Eq`.
pub trait VectorSpace:
Mul<f32, Output = Self>
+ Div<f32, Output = Self>
+ Add<Self, Output = Self>
+ Sub<Self, Output = Self>
+ Neg
+ Default
+ Debug
+ Clone
+ Copy
{
/// The zero vector, which is the identity of addition for the vector space type.
const ZERO: Self;
/// Perform vector space linear interpolation between this element and another, based
/// on the parameter `t`. When `t` is `0`, `self` is recovered. When `t` is `1`, `rhs`
/// is recovered.
///
/// Note that the value of `t` is not clamped by this function, so interpolating outside
/// of the interval `[0,1]` is allowed.
#[inline]
fn lerp(&self, rhs: Self, t: f32) -> Self {
*self * (1. - t) + rhs * t
}
}
```
```rust
/// A type that supports the operations of a normed vector space; i.e. a norm operation in addition
/// to those of [`VectorSpace`]. Specifically, the implementor must guarantee that the following
/// relationships hold, within the limitations of floating point arithmetic:
/// - (Nonnegativity) For all `v: Self`, `v.norm() >= 0.0`.
/// - (Positive definiteness) For all `v: Self`, `v.norm() == 0.0` implies `v == Self::ZERO`.
/// - (Absolute homogeneity) For all `c: f32`, `v: Self`, `(v * c).norm() == v.norm() * c.abs()`.
/// - (Triangle inequality) For all `v, w: Self`, `(v + w).norm() <= v.norm() + w.norm()`.
///
/// Note that, because implementing types use floating point arithmetic, they are not required to actually
/// implement `PartialEq` or `Eq`.
pub trait NormedVectorSpace: VectorSpace {
/// The size of this element. The return value should always be nonnegative.
fn norm(self) -> f32;
/// The squared norm of this element. Computing this is often faster than computing
/// [`NormedVectorSpace::norm`].
#[inline]
fn norm_squared(self) -> f32 {
self.norm() * self.norm()
}
/// The distance between this element and another, as determined by the norm.
#[inline]
fn distance(self, rhs: Self) -> f32 {
(rhs - self).norm()
}
/// The squared distance between this element and another, as determined by the norm. Note that
/// this is often faster to compute in practice than [`NormedVectorSpace::distance`].
#[inline]
fn distance_squared(self, rhs: Self) -> f32 {
(rhs - self).norm_squared()
}
}
```
Furthermore, this PR also demonstrates the use of the
`NormedVectorSpace` combined API to implement `ShapeSample` for
`Triangle2d` and `Triangle3d` simultaneously. Such deduplication is one
of the drivers for developing these APIs.
---
## Changelog
- `Point` from `cubic_splines` becomes `VectorSpace`, exported as
`bevy::math::VectorSpace`.
- `VectorSpace` requires `Neg` and `VectorSpace::ZERO` in addition to
its existing prerequisites.
- Introduced public traits `bevy::math::NormedVectorSpace` for generic
geometry tasks involving vectors.
- Implemented `ShapeSample` for `Triangle2d` and `Triangle3d`.
## Migration Guide
Since `Point` no longer exists, any projects using it must switch to
`bevy::math::VectorSpace`. Additionally, third-party implementations of
this trait now require the `Neg` trait; the constant `VectorSpace::ZERO`
must be provided as well.
---
## Discussion
### Design considerations
Originally, the `NormedVectorSpace::norm` method was part of a separate
trait `Normed`. However, I think that was probably too broad and, more
importantly, the semantics of having it in `NormedVectorSpace` are much
clearer.
As it currently stands, the API exposed here is pretty minimal, and
there is definitely a lot more that we could do, but there are more
questions to answer along the way. As a silly example, we could
implement `NormedVectorSpace::length` as an alias for
`NormedVectorSpace::norm`, but this overlaps with methods in all of the
glam types, so we would want to make sure that the implementations are
effectively identical (for what it's worth, I think they are already).
### Future directions
One example of something that could belong in the `NormedVectorSpace`
API is normalization. Actually, such a thing previously existed on this
branch before I decided to shelve it because of concerns with namespace
collision. It looked like this:
```rust
/// This element, but normalized to norm 1 if possible. Returns an error when the reciprocal of
/// the element's norm is not finite.
#[inline]
#[must_use]
fn normalize(&self) -> Result<Self, NonNormalizableError> {
let reciprocal = 1.0 / self.norm();
if reciprocal.is_finite() {
Ok(*self * reciprocal)
} else {
Err(NonNormalizableError { reciprocal })
}
}
/// An error indicating that an element of a [`NormedVectorSpace`] was non-normalizable due to having
/// non-finite norm-reciprocal.
#[derive(Debug, Error)]
#[error("Element with norm reciprocal {reciprocal} cannot be normalized")]
pub struct NonNormalizableError {
reciprocal: f32
}
```
With this kind of thing in hand, it might be worth considering
eventually making the passage from vectors to directions fully generic
by employing a wrapper type. (Of course, for our concrete types, we
would leave the existing names in place as aliases.) That is, something
like:
```rust
pub struct NormOne<T>
where T: NormedVectorSpace { //... }
```
Utterly separately, the reason that I implemented `ShapeSample` for
`Triangle2d`/`Triangle3d` was to prototype uniform sampling of abstract
meshes, so that's also a future direction.
---------
Co-authored-by: Zachary Harrold <zac@harrold.com.au>
# Objective
Since it is common to store a pair of width and height as `Vec2`, it
would be useful to have an easy way to instantiate `AspectRatio` from
`Vec2`.
## Solution
Add `impl From<Vec2> for AspectRatio`.
---
## Changelog
- Added `impl From<Vec2> for AspectRatio`
# Objective
- Fixes#12712
## Solution
- Move the `float_ord.rs` file to `bevy_math`
- Change any `bevy_utils::FloatOrd` statements to `bevy_math::FloatOrd`
---
## Changelog
- Moved `FloatOrd` from `bevy_utils` to `bevy_math`
## Migration Guide
- References to `bevy_utils::FloatOrd` should be changed to
`bevy_math::FloatOrd`
# Objective
Resolves#3824. `unsafe` code should be the exception, not the norm in
Rust. It's obviously needed for various use cases as it's interfacing
with platforms and essentially running the borrow checker at runtime in
the ECS, but the touted benefits of Bevy is that we are able to heavily
leverage Rust's safety, and we should be holding ourselves accountable
to that by minimizing our unsafe footprint.
## Solution
Deny `unsafe_code` workspace wide. Add explicit exceptions for the
following crates, and forbid it in almost all of the others.
* bevy_ecs - Obvious given how much unsafe is needed to achieve
performant results
* bevy_ptr - Works with raw pointers, even more low level than bevy_ecs.
* bevy_render - due to needing to integrate with wgpu
* bevy_window - due to needing to integrate with raw_window_handle
* bevy_utils - Several unsafe utilities used by bevy_ecs. Ideally moved
into bevy_ecs instead of made publicly usable.
* bevy_reflect - Required for the unsafe type casting it's doing.
* bevy_transform - for the parallel transform propagation
* bevy_gizmos - For the SystemParam impls it has.
* bevy_assets - To support reflection. Might not be required, not 100%
sure yet.
* bevy_mikktspace - due to being a conversion from a C library. Pending
safe rewrite.
* bevy_dynamic_plugin - Inherently unsafe due to the dynamic loading
nature.
Several uses of unsafe were rewritten, as they did not need to be using
them:
* bevy_text - a case of `Option::unchecked` could be rewritten as a
normal for loop and match instead of an iterator.
* bevy_color - the Pod/Zeroable implementations were replaceable with
bytemuck's derive macros.
# Objective
- #10572
There is no 2D primitive available for the common shape of an annulus
(ring).
## Solution
This PR introduces a new type to the existing math primitives:
- `Annulus`: the region between two concentric circles
---
## Changelog
### Added
- `Annulus` primitive to the `bevy_math` crate
- `Annulus` tests (`diameter`, `thickness`, `area`, `perimeter` and
`closest_point` methods)
---------
Co-authored-by: Joona Aalto <jondolf.dev@gmail.com>
# Objective
Currently the built docs only shows the logo and favicon for the top
level `bevy` crate. This makes views like
https://docs.rs/bevy_ecs/latest/bevy_ecs/ look potentially unrelated to
the project at first glance.
## Solution
Reproduce the docs attributes for every crate that Bevy publishes.
Ideally this would be done with some workspace level Cargo.toml control,
but AFAICT, such support does not exist.
# Context
[GitHub Discussion
Link](https://github.com/bevyengine/bevy/discussions/12506)
# Objective
- **Clarity:** More explicit representation of a common geometric
primitive.
- **Convenience:** Provide methods tailored to 3D triangles (area,
perimeters, etc.).
## Solution
- Adding the `Triangle3d` primitive into the `bevy_math` crate.
---
## Changelog
### Added
- `Triangle3d` primitive to the `bevy_math` crate
### Changed
- `Triangle2d::reverse`: the first and last vertices are swapped instead
of the second and third.
---------
Co-authored-by: Miles Silberling-Cook <NthTensor@users.noreply.github.com>
Co-authored-by: Joona Aalto <jondolf.dev@gmail.com>
# Objective
- Fixes#12570
## Solution
Previously, cardinal splines constructed by `CubicCardinalSpline` would
leave out their endpoints when constructing the cubic curve segments
connecting their points. (See the linked issue for details.)
Now, cardinal splines include the endpoints. For instance, the provided
usage example
```rust
let points = [
vec2(-1.0, -20.0),
vec2(3.0, 2.0),
vec2(5.0, 3.0),
vec2(9.0, 8.0),
];
let cardinal = CubicCardinalSpline::new(0.3, points).to_curve();
let positions: Vec<_> = cardinal.iter_positions(100).collect();
```
will actually produce a spline that connects all four of these points
instead of just the middle two "interior" points.
Internally, this is achieved by duplicating the endpoints of the vector
of control points before performing the construction of the associated
`CubicCurve`. This amounts to specifying that the tangents at the
endpoints `P_0` and `P_n` (say) should be parallel to `P_1 - P_0` and
`P_n - P_{n-1}`.
---
## Migration Guide
Any users relying on the old behavior of `CubicCardinalSpline` will have
to truncate any parametrizations they used in order to access a curve
identical to the one they had previously. This would be done by chopping
off a unit-distance segment from each end of the parametrizing interval.
For instance, if a user's existing code looks as follows
```rust
fn interpolate(t: f32) -> Vec2 {
let points = [
vec2(-1.0, -20.0),
vec2(3.0, 2.0),
vec2(5.0, 3.0),
vec2(9.0, 8.0),
];
let my_curve = CubicCardinalSpline::new(0.3, points).to_curve();
my_curve.position(t)
}
```
then in order to obtain similar behavior, `t` will need to be shifted up
by 1, since the output of `CubicCardinalSpline::to_curve` has introduced
a new segment in the interval [0,1], displacing the old segment from
[0,1] to [1,2]:
```rust
fn interpolate(t: f32) -> Vec2 {
let points = [
vec2(-1.0, -20.0),
vec2(3.0, 2.0),
vec2(5.0, 3.0),
vec2(9.0, 8.0),
];
let my_curve = CubicCardinalSpline::new(0.3, points).to_curve();
my_curve.position(t+1)
}
```
(Note that this does not provide identical output for values of `t`
outside of the interval [0,1].)
On the other hand, any user who was specifying additional endpoint
tangents simply to get the curve to pass through the right points (i.e.
not requiring exactly the same output) can simply omit the endpoints
that were being supplied only for control purposes.
---
## Discussion
### Design considerations
This is one of the two approaches outlined in #12570 — in this PR, we
are basically declaring that the docs are right and the implementation
was flawed.
One semi-interesting question is how the endpoint tangents actually
ought to be defined when we include them, and another option considered
was mirroring the control points adjacent to the endpoints instead of
duplicating them, which would have had the advantage that the expected
length of the corresponding difference should be more similar to that of
the other difference-tangents, provided that the points are equally
spaced.
In this PR, the duplication method (which produces smaller tangents) was
chosen for a couple reasons:
- It seems to be more standard
- It is exceptionally simple to implement
- I was a little concerned that the aforementioned alternative would
result in some over-extrapolation
### An annoyance
If you look at the code, you'll see I was unable to find a satisfactory
way of doing this without allocating a new vector. This doesn't seem
like a big problem given the context, but it does bother me. In
particular, if there is some easy parallel to `slice::windows` for
iterators that doesn't pull in an external dependency, I would love to
know about it.
# Objective
Currently in order to retrieve the inner values from direction types is
that you need to use the `Deref` trait or `From`/`Into`. `Deref` that is
currently implemented is an anti-pattern that I believe should be less
relied upon.
This pull-request add getters for retrieving the inner values for
direction types.
Advantages of getters:
- Let rust-analyzer to list out available methods for users to
understand better to on how to get the inner value. (This happens to me.
I really don't know how to get the value until I look through the source
code.)
- They are simple.
- Generally won't be ambiguous in most context. Traits such as
`From`/`Into` will require fully qualified syntax from time to time.
- Unsurprising result.
Disadvantages of getters:
- More verbose
Advantages of deref polymorphism:
- You reduce boilerplate for getting the value and call inner methods
by:
```rust
let dir = Dir3::new(Vec3::UP).unwrap();
// getting value
let value = *dir;
// instead of using getters
let value = dir.vec3();
// calling methods for the inner vector
dir.xy();
// instead of using getters
dir.vec3().xy();
```
Disadvantages of deref polymorphism:
- When under more level of indirection, it will requires more
dereferencing which will get ugly in some part:
```rust
// getting value
let value = **dir;
// instead of using getters
let value = dir.vec3();
// calling methods for the inner vector
dir.xy();
// instead of using getters
dir.vec3().xy();
```
[More detail
here](https://rust-unofficial.github.io/patterns/anti_patterns/deref.html).
Edit: Update information for From/Into trait.
Edit: Advantages and disadvantages.
## Solution
Add `vec2` method for Dir2.
Add `vec3` method for Dir3.
Add `vec3a` method for Dir3A.
# Objective
Give easy methods for uniform point sampling in a variety of primitive
shapes (particularly useful for circles and spheres) because in a lot of
cases its quite easy to get wrong (non-uniform).
## Solution
Added the `ShapeSample` trait to `bevy_math` and implemented it for
`Circle`, `Sphere`, `Rectangle`, `Cuboid`, `Cylinder`, `Capsule2d` and
`Capsule3d`. There are a few other shapes it would be reasonable to
implement for like `Triangle`, `Ellipse` and `Torus` but I'm not
immediately sure how these would be implemented (other than rejection
which could be the best method, and could be more performant than some
of the solutions in this pr I'm not sure). This exposes the
`sample_volume` and `sample_surface` methods to get both a random point
from its interior or its surface. EDIT: Renamed `sample_volume` to
`sample_interior` and `sample_surface` to `sample_boundary`
This brings in `rand` as a default optional dependency (without default
features), and the methods take `&mut impl Rng` which allows them to use
any random source implementing `RngCore`.
---
## Changelog
### Added
Added the methods `sample_interior` and `sample_boundary` to a variety
of primitive shapes providing easy uniform point sampling.
# Objective
Add a `scale_around_center` method to the `BoundingVolume` trait, as per
#12130.
## Solution
Added `scale_around_center` to the `BoundingVolume` trait, implemented
in `Aabb2d`, `Aabb3d`, `BoundingCircle`, and `BoundingSphere` (with
tests).
# Objective
Rotating vectors is a very common task. It is required for a variety of
things both within Bevy itself and in many third party plugins, for
example all over physics and collision detection, and for things like
Bevy's bounding volumes and several gizmo implementations.
For 3D, we can do this using a `Quat`, but for 2D, we do not have a
clear and efficient option. `Mat2` can be used for rotating vectors if
created using `Mat2::from_angle`, but this is not obvious to many users,
it doesn't have many rotation helpers, and the type does not give any
guarantees that it represents a valid rotation.
We should have a proper type for 2D rotations. In addition to allowing
for potential optimization, it would allow us to have a consistent and
explicitly documented representation used throughout the engine, i.e.
counterclockwise and in radians.
## Representation
The mathematical formula for rotating a 2D vector is the following:
```
new_x = x * cos - y * sin
new_y = x * sin + y * cos
```
Here, `sin` and `cos` are the sine and cosine of the rotation angle.
Computing these every time when a vector needs to be rotated can be
expensive, so the rotation shouldn't be just an `f32` angle. Instead, it
is often more efficient to represent the rotation using the sine and
cosine of the angle instead of storing the angle itself. This can be
freely passed around and reused without unnecessary computations.
The two options are either a 2x2 rotation matrix or a unit complex
number where the cosine is the real part and the sine is the imaginary
part. These are equivalent for the most part, but the unit complex
representation is a bit more memory efficient (two `f32`s instead of
four), so I chose that. This is like Nalgebra's
[`UnitComplex`](https://docs.rs/nalgebra/latest/nalgebra/geometry/type.UnitComplex.html)
type, which can be used for the
[`Rotation2`](https://docs.rs/nalgebra/latest/nalgebra/geometry/type.Rotation2.html)
type.
## Implementation
Add a `Rotation2d` type represented as a unit complex number:
```rust
/// A counterclockwise 2D rotation in radians.
///
/// The rotation angle is wrapped to be within the `]-pi, pi]` range.
pub struct Rotation2d {
/// The cosine of the rotation angle in radians.
///
/// This is the real part of the unit complex number representing the rotation.
pub cos: f32,
/// The sine of the rotation angle in radians.
///
/// This is the imaginary part of the unit complex number representing the rotation.
pub sin: f32,
}
```
Using it is similar to using `Quat`, but in 2D:
```rust
let rotation = Rotation2d::radians(PI / 2.0);
// Rotate vector (also works on Direction2d!)
assert_eq!(rotation * Vec2::X, Vec2::Y);
// Get angle as degrees
assert_eq!(rotation.as_degrees(), 90.0);
// Getting sin and cos is free
let (sin, cos) = rotation.sin_cos();
// "Subtract" rotations
let rotation2 = Rotation2d::FRAC_PI_4; // there are constants!
let diff = rotation * rotation2.inverse();
assert_eq!(diff.as_radians(), PI / 4.0);
// This is equivalent to the above
assert_eq!(rotation2.angle_between(rotation), PI / 4.0);
// Lerp
let rotation1 = Rotation2d::IDENTITY;
let rotation2 = Rotation2d::FRAC_PI_2;
let result = rotation1.lerp(rotation2, 0.5);
assert_eq!(result.as_radians(), std::f32::consts::FRAC_PI_4);
// Slerp
let rotation1 = Rotation2d::FRAC_PI_4);
let rotation2 = Rotation2d::degrees(-180.0); // we can use degrees too!
let result = rotation1.slerp(rotation2, 1.0 / 3.0);
assert_eq!(result.as_radians(), std::f32::consts::FRAC_PI_2);
```
There's also a `From<f32>` implementation for `Rotation2d`, which means
that methods can still accept radians as floats if the argument uses
`impl Into<Rotation2d>`. This means that adding `Rotation2d` shouldn't
even be a breaking change.
---
## Changelog
- Added `Rotation2d`
- Bounding volume methods now take an `impl Into<Rotation2d>`
- Gizmo methods with rotation now take an `impl Into<Rotation2d>`
## Future use cases
- Collision detection (a type like this is quite essential considering
how common vector rotations are)
- `Transform` helpers (e.g. return a 2D rotation about the Z axis from a
`Transform`)
- The rotation used for `Transform2d` (#8268)
- More gizmos, maybe meshes... everything in 2D that uses rotation
---------
Co-authored-by: Tristan Guichaoua <33934311+tguichaoua@users.noreply.github.com>
Co-authored-by: Robert Walter <robwalter96@gmail.com>
Co-authored-by: IQuick 143 <IQuick143cz@gmail.com>
# Objective
Fix missing `TextBundle` (and many others) which are present in the main
crate as default features but optional in the sub-crate. See:
- https://docs.rs/bevy/0.13.0/bevy/ui/node_bundles/index.html
- https://docs.rs/bevy_ui/0.13.0/bevy_ui/node_bundles/index.html
~~There are probably other instances in other crates that I could track
down, but maybe "all-features = true" should be used by default in all
sub-crates? Not sure.~~ (There were many.) I only noticed this because
rust-analyzer's "open docs" features takes me to the sub-crate, not the
main one.
## Solution
Add "all-features = true" to docs.rs metadata for crates that use
features.
## Changelog
### Changed
- Unified features documented on docs.rs between main crate and
sub-crates
# Objective
Fixes#12310.
#11681 added transformations for bounding volumes, but I accidentally
only added a note in the docs about repeated rotations for `Aabb2d` and
not `Aabb3d`.
## Solution
Copy the docs over to `Aabb3d`.
# Objective
Make it straightforward to translate and rotate bounding volumes.
## Solution
Add `translate_by`/`translated_by`, `rotate_by`/`rotated_by`,
`transform_by`/`transformed_by` methods to the `BoundingVolume` trait.
This follows the naming used for mesh transformations (see #11454 and
#11675).
---
## Changelog
- Added `translate_by`/`translated_by`, `rotate_by`/`rotated_by`,
`transform_by`/`transformed_by` methods to the `BoundingVolume` trait
and implemented them for the bounding volumes
- Renamed `Position` associated type to `Translation`
---------
Co-authored-by: Mateusz Wachowiak <mateusz_wachowiak@outlook.com>
# Objective
`Dir3` and `Dir3A` can be rotated using `Quat`s. However, if enough
floating point error accumulates or (more commonly) the rotation itself
is degenerate (like not normalized), the resulting direction can also
become denormalized.
Currently, with debug assertions enabled, it panics in these cases with
the message `rotated.is_normalized()`. This error message is unclear,
doesn't give information about *how* it is denormalized (like is the
length too large, NaN, or something else), and is overall not very
helpful. Panicking for small-ish error might also be a bit too strict,
and has lead to unwanted crashes in crates like `bevy_xpbd` (although it
has also helped in finding actual bugs).
The error message should be clearer and give more context, and it
shouldn't cause unwanted crashes.
## Solution
Change the `debug_assert!` to a warning for small error with a (squared
length) threshold of 2e-4 and a panic for clear error with a threshold
of 2e-2. The warnings mention the direction type and the length of the
denormalized vector.
Here's what the error and warning look like:
```
Error: `Dir3` is denormalized after rotation. The length is 1.014242.
```
```
Warning: `Dir3A` is denormalized after rotation. The length is 1.0001414.
```
I gave the same treatment to `new_unchecked`:
```
Error: The vector given to `Dir3::new_unchecked` is not normalized. The length is 1.014242.
```
```
Warning: The vector given to `Dir3A::new_unchecked` is not normalized. The length is 1.0001414.
```
---
## Discussion
### Threshold values
The thresholds are somewhat arbitrary. 2e-4 is what Glam uses for the
squared length in `is_normalized` (after I corrected it in
bitshifter/glam-rs#480), and 2e-2 is just what I thought could be a
clear sign of something being critically wrong. I can definitely tune
them if there are better thresholds though.
### Logging
`bevy_math` doesn't have `bevy_log`, so we can't use `warn!` or
`error!`. This is why I made it use just `eprintln!` and `panic!` for
now. Let me know if there's a better way of logging errors in
`bevy_math`.
# Objective
Bevy's `Dir3` and `Dir3A` only implement `Mul<f32>` and not vice versa,
and `Dir2` can not be multiplied by `f32` at all. They all should
implement multiplication both ways, just like Glam's vector types.
## Solution
Implement `Mul<Dir2>`, `Mul<Dir3>`, and `Mul<Dir3A>` for `f32`, and
`Mul<f32>` for `Dir2`.
# 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>
# Objective
Improve the `bevy::math::cubic_splines` module by making it more
flexible and adding new curve types.
Closes#10220
## Solution
Added new spline types and improved existing
---
## Changelog
### Added
- `CubicNurbs` rational cubic curve generator, allows setting the knot
vector and weights associated with every point
- `LinearSpline` curve generator, allows generating a linearly
interpolated curve segment
- Ability to push additional cubic segments to `CubicCurve`
- `IntoIterator` and `Extend` implementations for `CubicCurve`
### Changed
- `Point` trait has been implemented for more types: `Quat` and `Vec4`.
- `CubicCurve::coefficients` was moved to `CubicSegment::coefficients`
because the function returns `CubicSegment`, so it seems logical to be
associated with `CubicSegment` instead. The method is still not public.
### Fixed
- `CubicBSpline::new` was referencing Cardinal spline instead of
B-Spline
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: IQuick 143 <IQuick143cz@gmail.com>
Co-authored-by: Miles Silberling-Cook <nth.tensor@gmail.com>
Co-authored-by: Joona Aalto <jondolf.dev@gmail.com>
# Objective
Split up from #12017, add an aligned version of `Direction3d` for SIMD,
and move direction types out of `primitives`.
## Solution
Add `Direction3dA` and move direction types into a new `direction`
module.
---
## Migration Guide
The `Direction2d`, `Direction3d`, and `InvalidDirectionError` types have
been moved out of `bevy::math::primitives`.
Before:
```rust
use bevy::math::primitives::Direction3d;
```
After:
```rust
use bevy::math::Direction3d;
```
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
# Objective
- I hated having to do `Cuboid::new(1.0, 1.0, 1.0)` or
`Cuboid::from_size(Vec3::splat(1.0))` when there should be a much easier
way to do this.
## Solution
- Implemented a `from_length()` method that only takes in a single
float, and constructs a primitive of equal size in all directions.
- Ex:
```rs
// These:
Cuboid::new(1.0, 1.0, 1.0);
Cuboid::from_size(Vec3::splat(1.0));
// Are equivalent to this:
Cuboid::from_length(1.0);
```
- For the rest of the changed primitives:
```rs
Rectangle::from_length(1.0);
Plane3d::default().mesh().from_length(1.0);
```
# Objective
Split up from #11007, fixing most of the remaining work for #10569.
Implement `Meshable` for `Cuboid`, `Sphere`, `Cylinder`, `Capsule`,
`Torus`, and `Plane3d`. This covers all shapes that Bevy has mesh
structs for in `bevy_render::mesh::shapes`.
`Cone` and `ConicalFrustum` are new shapes, so I can add them in a
follow-up, or I could just add them here directly if that's preferrable.
## Solution
Implement `Meshable` for `Cuboid`, `Sphere`, `Cylinder`, `Capsule`,
`Torus`, and `Plane3d`.
The logic is mostly just a copy of the the existing `bevy_render`
shapes, but `Plane3d` has a configurable surface normal that affects the
orientation. Some property names have also been changed to be more
consistent.
The default values differ from the old shapes to make them a bit more
logical:
- Spheres now have a radius of 0.5 instead of 1.0. The default capsule
is equivalent to the default cylinder with the sphere's halves glued on.
- The inner and outer radius of the torus are now 0.5 and 1.0 instead of
0.5 and 1.5 (i.e. the new minor and major radii are 0.25 and 0.75). It's
double the width of the default cuboid, half of its height, and the
default sphere matches the size of the hole.
- `Cuboid` is 1x1x1 by default unlike the dreaded `Box` which is 2x1x1.
Before, with "old" shapes:
Now, with primitive meshing:
I only changed the `3d_shapes` example to use primitives for now. I can
change them all in this PR or a follow-up though, whichever way is
preferrable.
### Sphere API
Spheres have had separate `Icosphere` and `UVSphere` structs, but with
primitives we only have one `Sphere`.
We need to handle this with builders:
```rust
// Existing structs
let ico = Mesh::try_from(Icophere::default()).unwrap();
let uv = Mesh::from(UVSphere::default());
// Primitives
let ico = Sphere::default().mesh().ico(5).unwrap();
let uv = Sphere::default().mesh().uv(32, 18);
```
We could add methods on `Sphere` directly to skip calling `.mesh()`.
I also added a `SphereKind` enum that can be used with the `kind`
method:
```rust
let ico = Sphere::default()
.mesh()
.kind(SphereKind::Ico { subdivisions: 8 })
.build();
```
The default mesh for a `Sphere` is an icosphere with 5 subdivisions
(like the default `Icosphere`).
---
## Changelog
- Implement `Meshable` and `Default` for `Cuboid`, `Sphere`, `Cylinder`,
`Capsule`, `Torus`, and `Plane3d`
- Use primitives in `3d_shapes` example
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
# Objective
Currently the `missing_docs` lint is allowed-by-default and enabled at
crate level when their documentations is complete (see #3492).
This PR proposes to inverse this logic by making `missing_docs`
warn-by-default and mark crates with imcomplete docs allowed.
## Solution
Makes `missing_docs` warn at workspace level and allowed at crate level
when the docs is imcomplete.
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>
# Objective
Drawing a `Gizmos::circle` whose normal is derived from a Transform's
local axes now requires converting a Vec3 to a Direction3d and
unwrapping the result, and I think we shold move the conversion into
Bevy.
## Solution
We can make
`Transform::{left,right,up,down,forward,back,local_x,local_y,local_z}`
return a Direction3d, because they know that their results will be of
finite non-zero length (roughly 1.0).
---
## Changelog
`Transform::up()` and similar functions now return `Direction3d` instead
of `Vec3`.
## Migration Guide
Callers of `Transform::up()` and similar functions may have to
dereference the returned `Direction3d` to get to the inner `Vec3`.
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: Joona Aalto <jondolf.dev@gmail.com>
# Objective
- `RayTest` vs `AabbCast` and `CircleCast` is inconsistent
## Solution
- Renaming the other two would only make the name more confusing, so we
rename `RayTest2d/3d` to `RayCast2d/3d`
# Objective
It's often necessary to rotate directions, but it currently has to be
done like this:
```rust
Direction3d::new_unchecked(quat * *direction)
```
It'd be nice if you could rotate `Direction3d` directly:
```rust
quat * direction
```
## Solution
Implement `Mul<Direction3d>` for `Quat` ~~and the other way around.~~
(Glam doesn't impl `Mul<Quat>` or `MulAssign<Quat>` for `Vec3`)
The quaternion must be a unit quaternion to keep the direction
normalized, so there is a `debug_assert!` to be sure. Almost all `Quat`
constructors produce unit quaternions, so there should only be issues if
doing something like `quat + quat` instead of `quat * quat`, using
`Quat::from_xyzw` directly, or when you have significant enough drift
caused by e.g. physics simulation that doesn't normalize rotation. In
general, these would probably cause unexpected results anyway.
I also moved tests around slightly to make `dim2` and `dim3` more
consistent (`dim3` had *two* separate `test` modules for some reason).
In the future, we'll probably want a `Rotation2d` type that would
support the same for `Direction2d`. I considered implementing
`Mul<Mat2>` for `Direction2d`, but that would probably be more
questionable since `Mat2` isn't as clearly associated with rotations as
`Quat` is.
# Objective
- Add a basic form of shapecasting for bounding volumes
## Solution
- Implement AabbCast2d, AabbCast3d, BoundingCircleCast, and
BoundingSphereCast
- These are really just raycasts, but they modify the volumes the ray is
casting against
- The tests are slightly simpler, since they just use the raycast code
for the heavy lifting
