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Author SHA1 Message Date
Matty
23e87270df
A Curve trait for general interoperation — Part I (#14630)
# 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>
2024-08-09 14:19:44 +00:00
Matty
3484bd916f
Cyclic splines (#14106)
# 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.
2024-07-17 13:02:31 +00:00
Joona Aalto
36b521d069
Improve isometry docs (#14318)
# 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.
2024-07-15 16:05:33 +00:00
Matty
6c9ec88e54
Basic isometry types (#14269)
# 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`.
2024-07-14 15:27:42 +00:00
Matty
9af2ef740b
Make bevy_math::common_traits public (#14245)
# Objective

Fixes #14243 

## Solution

`bevy_math::common_traits` is now a public module.
2024-07-09 17:16:47 +00:00
Matty
a569b35c18
Stable interpolation and smooth following (#13741)
# 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.
2024-06-10 12:50:59 +00:00
Alice Cecile
2165f2218f
Rename Rotation2d to Rot2 (#13694)
# 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>
2024-06-05 21:51:13 +00:00
Bob Gardner
0db9fc92cd
Added CompassQuadrant and CompassOctant as per #13647 (#13653)
# 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>
2024-06-03 19:46:50 +00:00
Matty
3a7923ea92
Random sampling of directions and quaternions (#12857)
# 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.
2024-04-04 23:13:00 +00:00
Matty
f924b4d9ef
Move Point out of cubic splines module and expand it (#12747)
# 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>
2024-03-28 13:40:26 +00:00
Jacques Schutte
4508077297
Move FloatOrd into bevy_math (#12732)
# Objective

- Fixes #12712

## Solution

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

---

## Changelog

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

## Migration Guide

- References to `bevy_utils::FloatOrd` should be changed to
`bevy_math::FloatOrd`
2024-03-27 18:30:11 +00:00
James Liu
56bcbb0975
Forbid unsafe in most crates in the engine (#12684)
# 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.
2024-03-27 03:30:08 +00:00
James Liu
f096ad4155
Set the logo and favicon for all of Bevy's published crates (#12696)
# 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.
2024-03-25 18:52:50 +00:00
Ame
72c51cdab9
Make feature(doc_auto_cfg) work (#12642)
# Objective

- In #12366 `![cfg_attr(docsrs, feature(doc_auto_cfg))] `was added. But
to apply it it needs `--cfg=docsrs` in rustdoc-args.


## Solution

- Apply `--cfg=docsrs` to all crates and CI.

I also added `[package.metadata.docs.rs]` to all crates to avoid adding
code behind a feature and forget adding the metadata.

Before:

![Screenshot 2024-03-22 at 00 51
57](https://github.com/bevyengine/bevy/assets/104745335/6a9dfdaa-8710-4784-852b-5f9b74e3522c)

After:
![Screenshot 2024-03-22 at 00 51
32](https://github.com/bevyengine/bevy/assets/104745335/c5bd6d8e-8ddb-45b3-b844-5ecf9f88961c)
2024-03-23 02:22:52 +00:00
TheBigCheese
948ea3137a
Uniform point sampling methods for some primitive shapes. (#12484)
# 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.
2024-03-17 14:48:16 +00:00
Joona Aalto
f89af0567b
Add Rotation2d (#11658)
# 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>
2024-03-11 19:11:57 +00:00
Al M
52e3f2007b
Add "all-features = true" to docs.rs metadata for most crates (#12366)
# 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
2024-03-08 20:03:09 +00:00
Joona Aalto
f418de8eb6
Rename Direction2d/3d to Dir2/3 (#12189)
# Objective

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

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

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

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

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

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

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

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

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

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

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

## Solution

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

---

## Migration Guide

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

## Additional Context

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

---------

Co-authored-by: IceSentry <c.giguere42@gmail.com>
2024-02-28 22:48:43 +00:00
JohnTheCoolingFan
a543536a34
Cubic splines overhaul (#10701)
# 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>
2024-02-28 17:18:42 +00:00
Joona Aalto
9bd6cc0a5e
Add Direction3dA and move direction types out of primitives (#12018)
# 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>
2024-02-26 13:57:49 +00:00
Tristan Guichaoua
694c06f3d0
Inverse missing_docs logic (#11676)
# 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.
2024-02-03 21:40:55 +00:00
Joona Aalto
c6f45831e9
Add geometric primitives to bevy_math::prelude (#11432)
# Objective

Currently, the `primitives` module is inside of the prelude for
`bevy_math`, but the actual primitives are not. This requires either
importing the shapes everywhere that uses them, or adding the
`primitives::` prefix:

```rust
let rectangle = meshes.add(primitives::Rectangle::new(5.0, 2.5));
```

(Note: meshing isn't actually implemented yet, but it's in #11431)

The primitives are meant to be used for a variety of tasks across
several crates, like for meshing, bounding volumes, gizmos, colliders,
and so on, so I think having them in the prelude is justified. It would
make several common tasks a lot more ergonomic.

```rust
let rectangle = meshes.add(Rectangle::new(5.0, 2.5));
```

## Solution

Add `primitives::*` to `bevy_math::prelude`.

---------

Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
2024-01-20 20:15:38 +00:00
NiseVoid
c4e479a2d4
Implement bounding volume types (#10946)
# Objective

Implement bounding volume trait and the 4 types from
https://github.com/bevyengine/bevy/issues/10570. I will add intersection
tests in a future PR.

## Solution

Implement mostly everything as written in the issue, except:
- Intersection is no longer a method on the bounding volumes, but a
separate trait.
- I implemented a `visible_area` since it's the most common usecase to
care about the surface that could collide with cast rays.
  - Maybe we want both?

---

## Changelog

- Added bounding volume types to bevy_math

---------

Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
2024-01-10 23:18:51 +00:00
irate
ec14e946b8
Update glam, encase and hexasphere (#11082)
Update to `glam` 0.25, `encase` 0.7 and `hexasphere` to 10.0

## Changelog
Added the `FloatExt` trait to the `bevy_math` prelude which adds `lerp`,
`inverse_lerp` and `remap` methods to the `f32` and `f64` types.
2024-01-08 22:58:45 +00:00
Olle Lukowski
6b9cd57956
Introduce AspectRatio struct (#10368)
# Objective

- Fix an inconsistency in the calculation of aspect ratio's. 
- Fixes #10288 

## Solution

- Created an intermediate `AspectRatio` struct, as suggested in the
issue. This is currently just used in any places where aspect ratio
calculations happen, to prevent doing it wrong. In my and @mamekoro 's
opinion, it would be better if this was used instead of a normal `f32`
in various places, but I didn't want to make too many changes to begin
with.

## Migration Guide
- Anywhere where you are currently expecting a f32 when getting aspect
ratios, you will now receive a `AspectRatio` struct. this still holds
the same value.

---------

Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
2023-12-17 02:01:26 +00:00
Joona Aalto
d9aac887b5
Split Ray into Ray2d and Ray3d and simplify plane construction (#10856)
# Objective

A better alternative version of #10843.

Currently, Bevy has a single `Ray` struct for 3D. To allow better
interoperability with Bevy's primitive shapes (#10572) and some third
party crates (that handle e.g. spatial queries), it would be very useful
to have separate versions for 2D and 3D respectively.

## Solution

Separate `Ray` into `Ray2d` and `Ray3d`. These new structs also take
advantage of the new primitives by using `Direction2d`/`Direction3d` for
the direction:

```rust
pub struct Ray2d {
    pub origin: Vec2,
    pub direction: Direction2d,
}

pub struct Ray3d {
    pub origin: Vec3,
    pub direction: Direction3d,
}
```

and by using `Plane2d`/`Plane3d` in `intersect_plane`:

```rust
impl Ray2d {
    // ...
    pub fn intersect_plane(&self, plane_origin: Vec2, plane: Plane2d) -> Option<f32> {
        // ...
    }
}
```

---

## Changelog

### Added

- `Ray2d` and `Ray3d`
- `Ray2d::new` and `Ray3d::new` constructors
- `Plane2d::new` and `Plane3d::new` constructors

### Removed

- Removed `Ray` in favor of `Ray3d`

### Changed

- `direction` is now a `Direction2d`/`Direction3d` instead of a vector,
which provides guaranteed normalization
- `intersect_plane` now takes a `Plane2d`/`Plane3d` instead of just a
vector for the plane normal
- `Direction2d` and `Direction3d` now derive `Serialize` and
`Deserialize` to preserve ray (de)serialization

## Migration Guide

`Ray` has been renamed to `Ray3d`.

### Ray creation

Before:

```rust
Ray {
    origin: Vec3::ZERO,
    direction: Vec3::new(0.5, 0.6, 0.2).normalize(),
}
```

After:

```rust
// Option 1:
Ray3d {
    origin: Vec3::ZERO,
    direction: Direction3d::new(Vec3::new(0.5, 0.6, 0.2)).unwrap(),
}

// Option 2:
Ray3d::new(Vec3::ZERO, Vec3::new(0.5, 0.6, 0.2))
```

### Plane intersections

Before:

```rust
let result = ray.intersect_plane(Vec2::X, Vec2::Y);
```

After:

```rust
let result = ray.intersect_plane(Vec2::X, Plane2d::new(Vec2::Y));
```
2023-12-06 14:09:04 +00:00
Ame
951c9bb1a2
Add [lints] table, fix adding #![allow(clippy::type_complexity)] everywhere (#10011)
# Objective

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

## Solution

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

## Changelog

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

---------

Co-authored-by: Martín Maita <47983254+mnmaita@users.noreply.github.com>
2023-11-18 20:58:48 +00:00
NiseVoid
01b9ddd92c
Define a basic set of Primitives (#10466)
# Objective

- Implement a subset of
https://github.com/bevyengine/rfcs/blob/main/rfcs/12-primitive-shapes.md#feature-name-primitive-shapes

## Solution

- Define a very basic set of primitives in bevy_math
- Assume a 0,0,0 origin for most shapes
- Use radius and half extents to avoid unnecessary computational
overhead wherever they get used
- Provide both Boxed and const generics variants for shapes with
variable sizes
- Boxed is useful if a 3rd party crate wants to use something like
enum-dispatch for all supported primitives
- Const generics is useful when just working on a single primitive, as
it causes no allocs

#### Some discrepancies from the RFC:

- Box was changed to Cuboid, because Box is already used for an alloc
type
- Skipped Cone because it's unclear where the origin should be for
different uses
- Skipped Wedge because it's too niche for an initial PR (we also don't
implement Torus, Pyramid or a Death Star (there's an SDF for that!))
- Skipped Frustum because while it would be a useful math type, it's not
really a common primitive
- Skipped Triangle3d and Quad3d because those are just rotated 2D shapes

## Future steps

- Add more primitives
- Add helper methods to make primitives easier to construct (especially
when half extents are involved)
- Add methods to calculate AABBs for primitives (useful for physics, BVH
construction, for the mesh AABBs, etc)
- Add wrappers for common and cheap operations, like extruding 2D shapes
and translating them
- Use the primitives to generate meshes
- Provide signed distance functions and gradients for primitives (maybe)

---

## Changelog

- Added a collection of primitives to the bevy_math crate

---------

Co-authored-by: Joona Aalto <jondolf.dev@gmail.com>
2023-11-15 16:51:03 +00:00
Aevyrie
9d088dd144
Add Cubic prefix to all cubic curve generators (#10299)
# Objective

- Fixes #10258 

## Solution

- Renamed.

---

## Changelog

- Changed: `BSpline` -> `CubicBSpline`
- Changed: `CardinalSpline` -> `CubicCardinalSpline`
- Changed: `Hermite` -> `CubicHermite`

## Migration Guide

- Rename: `BSpline` -> `CubicBSpline`
- Rename: `CardinalSpline` -> `CubicCardinalSpline`
- Rename: `Hermite` -> `CubicHermite`
2023-10-28 21:53:38 +00:00
jnhyatt
087a345579
Rename Bezier to CubicBezier for clarity (#9554)
# Objective

A Bezier curve is a curve defined by two or more control points. In the
simplest form, it's just a line. The (arguably) most common type of
Bezier curve is a cubic Bezier, defined by four control points. These
are often used in animation, etc. Bevy has a Bezier curve struct called
`Bezier`. However, this is technically a misnomer as it only represents
cubic Bezier curves.

## Solution

This PR changes the struct name to `CubicBezier` to more accurately
reflect the struct's usage. Since it's exposed in Bevy's prelude, it can
potentially collide with other `Bezier` implementations. While that
might instead be an argument for removing it from the prelude, there's
also something to be said for adding a more general `Bezier` into Bevy,
in which case we'd likely want to use the name `Bezier`. As a final
motivator, not only is the struct located in `cubic_spines.rs`, there
are also several other spline-related structs which follow the
`CubicXxx` naming convention where applicable. For example,
`CubicSegment` represents a cubic Bezier curve (with coefficients
pre-baked).

---

## Migration Guide

- Change all `Bezier` references to `CubicBezier`
2023-08-28 17:37:42 +00:00
Robert Swain
0a11af9375
Reduce the size of MeshUniform to improve performance (#9416)
# Objective

- Significantly reduce the size of MeshUniform by only including
necessary data.

## Solution

Local to world, model transforms are affine. This means they only need a
4x3 matrix to represent them.

`MeshUniform` stores the current, and previous model transforms, and the
inverse transpose of the current model transform, all as 4x4 matrices.
Instead we can store the current, and previous model transforms as 4x3
matrices, and we only need the upper-left 3x3 part of the inverse
transpose of the current model transform. This change allows us to
reduce the serialized MeshUniform size from 208 bytes to 144 bytes,
which is over a 30% saving in data to serialize, and VRAM bandwidth and
space.

## Benchmarks

On an M1 Max, running `many_cubes -- sphere`, main is in yellow, this PR
is in red:
<img width="1484" alt="Screenshot 2023-08-11 at 02 36 43"
src="https://github.com/bevyengine/bevy/assets/302146/7d99c7b3-f2bb-4004-a8d0-4c00f755cb0d">
A reduction in frame time of ~14%.

---

## Changelog

- Changed: Redefined `MeshUniform` to improve performance by using 4x3
affine transforms and reconstructing 4x4 matrices in the shader. Helper
functions were added to `bevy_pbr::mesh_functions` to unpack the data.
`affine_to_square` converts the packed 4x3 in 3x4 matrix data to a 4x4
matrix. `mat2x4_f32_to_mat3x3` converts the 3x3 in mat2x4 + f32 matrix
data back into a 3x3.

## Migration Guide

Shader code before:
```
var model = mesh[instance_index].model;
```

Shader code after:
```
#import bevy_pbr::mesh_functions affine_to_square

var model = affine_to_square(mesh[instance_index].model);
```
2023-08-15 06:00:23 +00:00
Tristan Guichaoua
37915e1d93
Add glam swizzles traits to prelude (#9387)
# Objective

Add possibility to use the glam's swizzles traits without having to
manually import them.

```diff
use bevy::prelude::*;
- use bevy::math::Vec3Swizzles;

fn foo(x: Vec3) {
    let y: Vec2 = x.xy();
}
```

## Solution

Add the swizzles traits to bevy's prelude.

---

## Changelog

- `Vec2Swizzles`, `Vec3Swizzles` and `Vec4Swizzles` are now part of the
prelude.
2023-08-10 17:05:01 +00:00
Ame
7154b59438
Return URect instead of (UVec2, UVec2) in Camera::physical_viewport_rect (#9085)
# Objective

Continue #7867 now that we have URect #7984
- Return `URect` instead of `(UVec2, UVec2)` in
`Camera::physical_viewport_rect`
 - Add `URect` and `IRect` to prelude

## Changelog

- Changed `Camera::physical_viewport_rect` return type from `(UVec2,
UVec2)` to `URect`
- `URect` and `IRect` were added to prelude

## Migration Guide

Before:

```rust
fn view_physical_camera_rect(camera_query: Query<&Camera>) {
    let camera = camera_query.single();
    let Some((min, max)) = camera.physical_viewport_rect() else { return };
    dbg!(min, max);
}
```

After:

```rust
fn view_physical_camera_rect(camera_query: Query<&Camera>) {
    let camera = camera_query.single();
    let Some(URect { min, max }) = camera.physical_viewport_rect() else { return };
    dbg!(min, max);
}
```
2023-07-15 21:25:22 +00:00
Liam Gallagher
942766c485
Add integer equivalents for Rect (#7984)
## Objective

Add integer equivalents for the `Rect` type.

Closes #7967

## Solution

- Add `IRect` and `URect`

## Changelog

Added `IRect` and `URect` types.
2023-06-12 19:10:48 +00:00
JoJoJet
3ead10a3e0
Suppress the clippy::type_complexity lint (#8313)
# Objective

The clippy lint `type_complexity` is known not to play well with bevy.
It frequently triggers when writing complex queries, and taking the
lint's advice of using a type alias almost always just obfuscates the
code with no benefit. Because of this, this lint is currently ignored in
CI, but unfortunately it still shows up when viewing bevy code in an
IDE.

As someone who's made a fair amount of pull requests to this repo, I
will say that this issue has been a consistent thorn in my side. Since
bevy code is filled with spurious, ignorable warnings, it can be very
difficult to spot the *real* warnings that must be fixed -- most of the
time I just ignore all warnings, only to later find out that one of them
was real after I'm done when CI runs.

## Solution

Suppress this lint in all bevy crates. This was previously attempted in
#7050, but the review process ended up making it more complicated than
it needs to be and landed on a subpar solution.

The discussion in https://github.com/rust-lang/rust-clippy/pull/10571
explores some better long-term solutions to this problem. Since there is
no timeline on when these solutions may land, we should resolve this
issue in the meantime by locally suppressing these lints.

### Unresolved issues

Currently, these lints are not suppressed in our examples, since that
would require suppressing the lint in every single source file. They are
still ignored in CI.
2023-04-06 21:27:36 +00:00
Aevyrie
2ea0061018 Add generic cubic splines to bevy_math (#7683)
# Objective

- Make cubic splines more flexible and more performant
- Remove the existing spline implementation that is generic over many degrees
  - This is a potential performance footgun and adds type complexity for negligible gain.
- Add implementations of:
  - Bezier splines
  - Cardinal splines (inc. Catmull-Rom)
  - B-Splines
  - Hermite splines

https://user-images.githubusercontent.com/2632925/221780519-495d1b20-ab46-45b4-92a3-32c46da66034.mp4


https://user-images.githubusercontent.com/2632925/221780524-2b154016-699f-404f-9c18-02092f589b04.mp4


https://user-images.githubusercontent.com/2632925/221780525-f934f99d-9ad4-4999-bae2-75d675f5644f.mp4


## Solution

- Implements the concept that splines are curve generators (e.g. https://youtu.be/jvPPXbo87ds?t=3488) via the `CubicGenerator` trait.
- Common splines are bespoke data types that implement this trait. This gives us flexibility to add custom spline-specific methods on these types, while ultimately all generating a `CubicCurve`.
- All splines generate `CubicCurve`s, which are a chain of precomputed polynomial coefficients. This means that all splines have the same evaluation cost, as the calculations for determining position, velocity, and acceleration are all identical. In addition, `CubicCurve`s are simply a list of `CubicSegment`s, which are evaluated from t=0 to t=1. This also means cubic splines of different type can be chained together, as ultimately they all are simply a collection of `CubicSegment`s.
- Because easing is an operation on a singe segment of a Bezier curve, we can simply implement easing on `Beziers` that use the `Vec2` type for points. Higher level crates such as `bevy_ui` can wrap this in a more ergonomic interface as needed.

### Performance
Measured on a desktop i5 8600K (6-year-old CPU):
- easing: 2.7x faster (19ns)
- cubic vec2 position sample: 1.5x faster (1.8ns)
- cubic vec3 position sample: 1.5x faster (2.6ns)
- cubic vec3a position sample: 1.9x faster (1.4ns)

On a laptop i7 11800H:
- easing: 16ns
- cubic vec2 position sample: 1.6ns
- cubic vec3 position sample: 2.3ns
- cubic vec3a position sample: 1.2ns

---

## Changelog

- Added a generic cubic curve trait, and implementation for Cardinal splines (including Catmull-Rom), B-Splines, Beziers, and Hermite Splines. 2D cubic curve segments also implement easing functionality for animation.
2023-03-03 22:06:42 +00:00
Aevyrie
2a598d3e5a Add Beziers to bevy_math (#7653)
# Objective

- Adds foundational math for Bezier curves, useful for UI/2D/3D animation and smooth paths.

https://user-images.githubusercontent.com/2632925/218883143-e138f994-1795-40da-8c59-21d779666991.mp4

## Solution

- Adds the generic `Bezier` type, and a `Point` trait. The `Point` trait allows us to use control points of any dimension, as long as they support vector math. I've implemented it for `f32`(1D), `Vec2`(2D), and `Vec3`/`Vec3A`(3D).
- Adds `CubicBezierEasing` on top of `Bezier` with the addition of an implementation of cubic Bezier easing, which is a foundational tool for UI animation.
  - This involves solving for $t$ in the parametric Bezier function $B(t)$ using the Newton-Raphson method to find a value with error $\leq$ 1e-7, capped at 8 iterations.
- Added type aliases for common Bezier curves: `CubicBezier2d`, `CubicBezier3d`, `QuadraticBezier2d`, and `QuadraticBezier3d`. These types use `Vec3A` to represent control points, as this was found to have an 80-90% speedup over using `Vec3`.
- Benchmarking shows quadratic/cubic Bezier evaluations $B(t)$ take \~1.8/2.4ns respectively. Easing, which requires an iterative solve takes \~50ns for cubic Beziers. 

---

## Changelog

- Added `CubicBezier2d`, `CubicBezier3d`, `QuadraticBezier2d`, and `QuadraticBezier3d` types with methods for sampling position, velocity, and acceleration. The generic `Bezier` type is also available, and generic over any degree of Bezier curve.
- Added `CubicBezierEasing`, with additional methods to allow for smooth easing animations.
2023-02-20 18:34:52 +00:00
Alice Cecile
334e09892b Revert "Show prelude re-exports in docs (#6448)" (#6449)
This reverts commit 53d387f340.

# Objective

Reverts #6448. This didn't have the intended effect: we're now getting bevy::prelude shown in the docs again.

Co-authored-by: Alejandro Pascual <alejandro.pascual.pozo@gmail.com>
2022-11-02 20:40:45 +00:00
Alejandro Pascual
53d387f340 Show prelude re-exports in docs (#6448)
# Objective

- Right now re-exports are completely hidden in prelude docs.
- Fixes #6433

## Solution

- We could show the re-exports without inlining their documentation.
2022-11-02 19:35:06 +00:00
ira
37860a09de Add Camera::viewport_to_world (#6126)
# Objective

Add a method for getting a world space ray from a viewport position.

Opted to add a `Ray` type to `bevy_math` instead of returning a tuple of `Vec3`'s as this is clearer and easier to document
The docs on `viewport_to_world` are okay, but I'm not super happy with them.

## Changelog
* Add `Camera::viewport_to_world`
* Add `Camera::ndc_to_world`
* Add `Ray` to `bevy_math`
* Some doc tweaks

Co-authored-by: devil-ira <justthecooldude@gmail.com>
2022-10-05 22:16:26 +00:00
Jerome Humbert
8b7b44d839 Move sprite::Rect into bevy_math (#5686)
# Objective

Promote the `Rect` utility of `sprite::Rect`, which defines a rectangle
by its minimum and maximum corners, to the `bevy_math` crate to make it
available as a general math type to all crates without the need to
depend on the `bevy_sprite` crate.

Fixes #5575

## Solution

Move `sprite::Rect` into `bevy_math` and fix all uses.

Implement `Reflect` for `Rect` directly into the `bevy_reflect` crate by
having `bevy_reflect` depend on `bevy_math`. This looks like a new
dependency, but the `bevy_reflect` was "cheating" for other math types
by directly depending on `glam` to reflect other math types, thereby
giving the illusion that there was no dependency on `bevy_math`. In
practice conceptually Bevy's math types are reflected into the
`bevy_reflect` crate to avoid a dependency of that crate to a "lower
level" utility crate like `bevy_math` (which in turn would make
`bevy_reflect` be a dependency of most other crates, and increase the
risk of circular dependencies). So this change simply formalizes that
dependency in `Cargo.toml`.

The `Rect` struct is also augmented in this change with a collection of
utility methods to improve its usability. A few uses cases are updated
to use those new methods, resulting is more clear and concise syntax.

---

## Changelog

### Changed

- Moved the `sprite::Rect` type into `bevy_math`.

### Added

- Added several utility methods to the `math::Rect` type.

## Migration Guide

The `bevy::sprite::Rect` type moved to the math utility crate as
`bevy::math::Rect`. You should change your imports from `use
bevy::sprite::Rect` to `use bevy::math::Rect`.
2022-09-02 12:35:23 +00:00
ira
56ee620495 Export and register Mat2. (#5324)
Export and register a missing type from `glam`.

Reflect impls were already present, but not registered.


Co-authored-by: devil-ira <justthecooldude@gmail.com>
2022-07-15 22:37:06 +00:00
KDecay
18b27269c0 Document bevy_math (#4591)
# Objective

- Part of #3492

## Solution

- Document the `bevy_math` crate and add the `#![warn(missing_docs)]` lint.
2022-04-26 18:23:29 +00:00
KDecay
989fb8a78d Move Rect to bevy_ui and rename it to UiRect (#4276)
# Objective

- Closes #335.
- Related #4285.
- Part of the splitting process of #3503.

## Solution

- Move `Rect` to `bevy_ui` and rename it to `UiRect`.

## Reasons

- `Rect` is only used in `bevy_ui` and therefore calling it `UiRect` makes the intent clearer.
- We have two types that are called `Rect` currently and it's missleading (see `bevy_sprite::Rect` and #335).
- Discussion in #3503.

## Changelog

### Changed

- The `Rect` type got moved from `bevy_math` to `bevy_ui` and renamed to `UiRect`.

## Migration Guide

- The `Rect` type got renamed to `UiRect`. To migrate you just have to change every occurrence of `Rect` to `UiRect`.

Co-authored-by: KDecay <KDecayMusic@protonmail.com>
2022-04-25 19:20:38 +00:00
KDecay
7a7f097485 Move Size to bevy_ui (#4285)
# Objective

- Related #4276.
- Part of the splitting process of #3503.

## Solution

- Move `Size` to `bevy_ui`.

## Reasons

- `Size` is only needed in `bevy_ui` (because it needs to use `Val` instead of `f32`), but it's also used as a worse `Vec2`  replacement in other areas.
- `Vec2` is more powerful than `Size` so it should be used whenever possible.
- Discussion in #3503.

## Changelog

### Changed

- The `Size` type got moved from `bevy_math` to `bevy_ui`.

## Migration Guide

- The `Size` type got moved from `bevy::math` to `bevy::ui`. To migrate you just have to import `bevy::ui::Size` instead of `bevy::math::Math` or use the `bevy::prelude` instead.

Co-authored-by: KDecay <KDecayMusic@protonmail.com>
2022-04-25 13:54:46 +00:00
KDecay
f90da74e32 Remove face_toward.rs (#4277)
# Objective

- Part of the splitting process of #3503.

## Solution

- Remove the `face_toward.rs` file containing the `FaceToward` trait.

## Reasons

- It is unused inside of `bevy`.
- The method `Mat4::face_toward` of the trait is identical to `Mat4::look_at_rh` (see https://docs.rs/glam/latest/glam/f32/struct.Mat4.html#method.look_at_rh).
- Discussion in #3503.

## Changelog

### Removed

- The `FaceToward` trait got removed.

## Migration Guide

-  The `FaceToward` trait got removed. To migrate you just have to change every occurrence of `Mat4::face_toward` to `Mat4::look_at_rh`.
2022-04-03 14:40:46 +00:00
Carter Anderson
ffecb05a0a Replace old renderer with new renderer (#3312)
This makes the [New Bevy Renderer](#2535) the default (and only) renderer. The new renderer isn't _quite_ ready for the final release yet, but I want as many people as possible to start testing it so we can identify bugs and address feedback prior to release.

The examples are all ported over and operational with a few exceptions:

* I removed a good portion of the examples in the `shader` folder. We still have some work to do in order to make these examples possible / ergonomic / worthwhile: #3120 and "high level shader material plugins" are the big ones. This is a temporary measure.
* Temporarily removed the multiple_windows example: doing this properly in the new renderer will require the upcoming "render targets" changes. Same goes for the render_to_texture example.
* Removed z_sort_debug: entity visibility sort info is no longer available in app logic. we could do this on the "render app" side, but i dont consider it a priority.
2021-12-14 03:58:23 +00:00
Lucas Rocha
b1ed28e17e Hide re-exported docs (#1985)
Solves #1957 

Co-authored-by: caelumLaron <caelum.laron@gmail.com>
2021-04-27 18:29:33 +00:00
François
75ae20dc4a use std clamp instead of Bevy's (#1644)
Rust std's `clamp` has been stabilised in 1.50: https://github.com/rust-lang/rust/issues/44095

This is already the minimum supported version, so no change there 👍
2021-03-13 18:07:14 +00:00
TheRawMeatball
f15d62c0f1
More types (#1267) 2021-01-21 16:05:23 -08:00