Trait vek::ops::Lerp [−][src]
pub trait Lerp<Factor = f32>: Sized {
type Output;
fn lerp_unclamped(from: Self, to: Self, factor: Factor) -> Self::Output;
fn lerp_unclamped_inclusive_range(
range: RangeInclusive<Self>,
factor: Factor
) -> Self::Output { ... }
fn lerp_unclamped_precise(
from: Self,
to: Self,
factor: Factor
) -> Self::Output { ... }
fn lerp_unclamped_precise_inclusive_range(
range: RangeInclusive<Self>,
factor: Factor
) -> Self::Output { ... }
fn lerp(from: Self, to: Self, factor: Factor) -> Self::Output
where
Factor: Clamp + Zero + One,
{ ... }
fn lerp_inclusive_range(
range: RangeInclusive<Self>,
factor: Factor
) -> Self::Output
where
Factor: Clamp + Zero + One,
{ ... }
fn lerp_precise(from: Self, to: Self, factor: Factor) -> Self::Output
where
Factor: Clamp + Zero + One,
{ ... }
fn lerp_precise_inclusive_range(
range: RangeInclusive<Self>,
factor: Factor
) -> Self::Output
where
Factor: Clamp + Zero + One,
{ ... }
}
Expand description
A value that can be linearly interpolated.
Note that, like standard operators, this can be implement for T
and &T
.
You would make the difference like so:
use vek::ops::Lerp;
let a = Lerp::lerp(0, 10, 0.5_f32);
let b = Lerp::lerp(&0, &10, 0.5_f32);
let c = i32::lerp(0, 10, 0.5_f32);
let d = <&i32>::lerp(&0, &10, 0.5_f32);
assert_eq!(a, b);
assert_eq!(a, c);
assert_eq!(a, d);
This is made possible thanks to the explicit Output
type.
Therefore, it’s also convenient for GameState
structures, which you might
prefer to interpolate by reference instead of consuming them.
The interpolation of two &GameState
s would produce a new GameState
value.
use vek::{Lerp, Vec3};
/// A data-heavy structure that represents a current game state.
/// It's neither Copy and nor even Clone!
struct GameState {
pub camera_position: Vec3<f32>,
// ... obviously a lot of other members following ...
}
// We can select the Progress type. I chose f64; the default is f32.
impl<'a> Lerp<f64> for &'a GameState {
type Output = GameState;
fn lerp_unclamped(a: Self, b: Self, t: f64) -> GameState {
GameState {
camera_position: Lerp::lerp(a.camera_position, b.camera_position, t as f32),
// ... etc for all relevant members...
}
}
}
let a = GameState { camera_position: Vec3::zero() };
let b = GameState { camera_position: Vec3::unit_x() };
let c = Lerp::lerp(&a, &b, 0.5);
// Hurray! We've got an interpolated state without consuming the two previous ones.
Associated Types
Required methods
fn lerp_unclamped(from: Self, to: Self, factor: Factor) -> Self::Output
fn lerp_unclamped(from: Self, to: Self, factor: Factor) -> Self::Output
Returns the linear interpolation of from
to to
with factor
unconstrained,
using the supposedly fastest but less precise implementation.
A possible implementation is from + factor * (to - from)
, a.k.a
factor.mul_add(to - from, from)
.
use vek::ops::Lerp;
assert_eq!(Lerp::lerp_unclamped(10, 20, -1.0_f32), 0);
assert_eq!(Lerp::lerp_unclamped(10, 20, -0.5_f32), 5);
assert_eq!(Lerp::lerp_unclamped(10, 20, 0.0_f32), 10);
assert_eq!(Lerp::lerp_unclamped(10, 20, 0.5_f32), 15);
assert_eq!(Lerp::lerp_unclamped(10, 20, 1.0_f32), 20);
assert_eq!(Lerp::lerp_unclamped(10, 20, 1.5_f32), 25);
Provided methods
fn lerp_unclamped_inclusive_range(
range: RangeInclusive<Self>,
factor: Factor
) -> Self::Output
fn lerp_unclamped_inclusive_range(
range: RangeInclusive<Self>,
factor: Factor
) -> Self::Output
Version of lerp_unclamped()
that used a single RangeInclusive
parameter instead of two values.
fn lerp_unclamped_precise(from: Self, to: Self, factor: Factor) -> Self::Output
fn lerp_unclamped_precise(from: Self, to: Self, factor: Factor) -> Self::Output
Returns the linear interpolation of from
to to
with factor
unconstrained,
using a possibly slower but more precise operation.
A possible implementation is from*(1-factor) + to*factor
, a.k.a
from.mul_add(1-factor, to*factor)
.
use vek::ops::Lerp;
assert_eq!(Lerp::lerp_unclamped_precise(10, 20, -1.0_f32), 0);
assert_eq!(Lerp::lerp_unclamped_precise(10, 20, -0.5_f32), 5);
assert_eq!(Lerp::lerp_unclamped_precise(10, 20, 0.0_f32), 10);
assert_eq!(Lerp::lerp_unclamped_precise(10, 20, 0.5_f32), 15);
assert_eq!(Lerp::lerp_unclamped_precise(10, 20, 1.0_f32), 20);
assert_eq!(Lerp::lerp_unclamped_precise(10, 20, 1.5_f32), 25);
fn lerp_unclamped_precise_inclusive_range(
range: RangeInclusive<Self>,
factor: Factor
) -> Self::Output
fn lerp_unclamped_precise_inclusive_range(
range: RangeInclusive<Self>,
factor: Factor
) -> Self::Output
Version of lerp_unclamped_precise()
that used a single RangeInclusive
parameter instead of two values.
Alias to lerp_unclamped
which constrains factor
to be between 0 and 1
(inclusive).
use vek::ops::Lerp;
assert_eq!(Lerp::lerp(10, 20, -1.0_f32), 10);
assert_eq!(Lerp::lerp(10, 20, -0.5_f32), 10);
assert_eq!(Lerp::lerp(10, 20, 0.0_f32), 10);
assert_eq!(Lerp::lerp(10, 20, 0.5_f32), 15);
assert_eq!(Lerp::lerp(10, 20, 1.0_f32), 20);
assert_eq!(Lerp::lerp(10, 20, 1.5_f32), 20);
fn lerp_inclusive_range(
range: RangeInclusive<Self>,
factor: Factor
) -> Self::Output where
Factor: Clamp + Zero + One,
fn lerp_inclusive_range(
range: RangeInclusive<Self>,
factor: Factor
) -> Self::Output where
Factor: Clamp + Zero + One,
Version of lerp()
that used a single RangeInclusive
parameter instead of two values.
Alias to lerp_unclamped_precise
which constrains factor
to be between 0 and 1
(inclusive).
use vek::ops::Lerp;
assert_eq!(Lerp::lerp_precise(10, 20, -1.0_f32), 10);
assert_eq!(Lerp::lerp_precise(10, 20, -0.5_f32), 10);
assert_eq!(Lerp::lerp_precise(10, 20, 0.0_f32), 10);
assert_eq!(Lerp::lerp_precise(10, 20, 0.5_f32), 15);
assert_eq!(Lerp::lerp_precise(10, 20, 1.0_f32), 20);
assert_eq!(Lerp::lerp_precise(10, 20, 1.5_f32), 20);
fn lerp_precise_inclusive_range(
range: RangeInclusive<Self>,
factor: Factor
) -> Self::Output where
Factor: Clamp + Zero + One,
fn lerp_precise_inclusive_range(
range: RangeInclusive<Self>,
factor: Factor
) -> Self::Output where
Factor: Clamp + Zero + One,
Version of lerp_precise()
that used a single RangeInclusive
parameter instead of two values.
Implementations on Foreign Types
Implementors
LERP on a Transform
is defined as LERP-ing between the positions and scales,
and performing SLERP between the orientations.
LERP on a Transform
is defined as LERP-ing between the positions and scales,
and performing SLERP between the orientations.
LERP on a Transform
is defined as LERP-ing between the positions and scales,
and performing SLERP between the orientations.
type Output = Self
LERP on a Transform
is defined as LERP-ing between the positions and scales,
and performing SLERP between the orientations.