# Objective
Citing @mweatherley
> There is a lot of shortfall for simple cases— e.g., we should have
library functions for making a curve connecting two points, eased
versions of that, and so on.
## Solution
This PR implements
- a simple `Easing` trait which is implemented for all `impl Curve<f32>`
types. We can't really guarantee that these curves have unit interval
domain, which some people would probably expect, but it is documented
that this isn't the case for these types and we redirect to
`EasingCurve` which is used for that purpose
- an `EasingCurve` struct, which is used to interpolate between two
values `start` and `end` using a `impl Easing` curve where the curve
will be guaranteed to be reparametrized
- a `LinearCurve` which linearly interpolates between two values `start`
and `end`
- a `CubicBezierCurve` which interpolates between `start` and `end`
values using a `CubicSegment`
- a `StepCurve` which interpolates between `start` and `end` with an
step-function with `n` steps
- an `ElasticCurve` which interpolates between `start` and `end` with
spring like behavior where the elasticity of the spring is configurable
- some `FunctionCurve` easing curves for different popular functions
including: `quadratic_ease_in`, `quadratic_ease_out`, `smoothstep`,
`identity`
## Testing
- there are a few new tests for all of these in the main module
---------
Co-authored-by: eckz <567737+eckz@users.noreply.github.com>
Co-authored-by: Miles Silberling-Cook <NthTensor@users.noreply.github.com>
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: Matty <weatherleymatthew@gmail.com>
# Objective
- Fixes#6370
- Closes#6581
## Solution
- Added the following lints to the workspace:
- `std_instead_of_core`
- `std_instead_of_alloc`
- `alloc_instead_of_core`
- Used `cargo +nightly fmt` with [item level use
formatting](https://rust-lang.github.io/rustfmt/?version=v1.6.0&search=#Item%5C%3A)
to split all `use` statements into single items.
- Used `cargo clippy --workspace --all-targets --all-features --fix
--allow-dirty` to _attempt_ to resolve the new linting issues, and
intervened where the lint was unable to resolve the issue automatically
(usually due to needing an `extern crate alloc;` statement in a crate
root).
- Manually removed certain uses of `std` where negative feature gating
prevented `--all-features` from finding the offending uses.
- Used `cargo +nightly fmt` with [crate level use
formatting](https://rust-lang.github.io/rustfmt/?version=v1.6.0&search=#Crate%5C%3A)
to re-merge all `use` statements matching Bevy's previous styling.
- Manually fixed cases where the `fmt` tool could not re-merge `use`
statements due to conditional compilation attributes.
## Testing
- Ran CI locally
## Migration Guide
The MSRV is now 1.81. Please update to this version or higher.
## Notes
- This is a _massive_ change to try and push through, which is why I've
outlined the semi-automatic steps I used to create this PR, in case this
fails and someone else tries again in the future.
- Making this change has no impact on user code, but does mean Bevy
contributors will be warned to use `core` and `alloc` instead of `std`
where possible.
- This lint is a critical first step towards investigating `no_std`
options for Bevy.
---------
Co-authored-by: François Mockers <francois.mockers@vleue.com>
# Objective
This is a value that is and will be used as a domain of curves pretty
often. By adding it as a dedicated constant we can get rid of some
`unwraps` and function calls.
## Solution
added `Interval::UNIT`
## Testing
I replaced all occurrences of `interval(0.0, 1.0).unwrap()` with the new
`Interval::UNIT` constant in tests and doc tests.
# 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).
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Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
