pub trait Lerp<Factor = f32>: Sized {
type Output;
// Required method
fn lerp_unclamped(from: Self, to: Self, factor: Factor) -> Self::Output;
// Provided methods
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 &GameStates 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.Required Associated Types§
Required Methods§
sourcefn 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§
sourcefn 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.
sourcefn 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);sourcefn 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.
sourcefn lerp(from: Self, to: Self, factor: Factor) -> Self::Output
fn lerp(from: Self, to: Self, factor: Factor) -> Self::Output
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);sourcefn lerp_inclusive_range(
range: RangeInclusive<Self>,
factor: Factor,
) -> Self::Output
fn lerp_inclusive_range( range: RangeInclusive<Self>, factor: Factor, ) -> Self::Output
Version of lerp() that used a single RangeInclusive parameter instead of two values.
sourcefn lerp_precise(from: Self, to: Self, factor: Factor) -> Self::Output
fn lerp_precise(from: Self, to: Self, factor: Factor) -> Self::Output
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);sourcefn lerp_precise_inclusive_range(
range: RangeInclusive<Self>,
factor: Factor,
) -> Self::Output
fn lerp_precise_inclusive_range( range: RangeInclusive<Self>, factor: Factor, ) -> Self::Output
Version of lerp_precise() that used a single RangeInclusive parameter instead of two values.
Object Safety§
Implementations on Foreign Types§
source§impl Lerp for f32
impl Lerp for f32
type Output = f32
fn lerp_unclamped_precise(from: Self, to: Self, factor: Self) -> Self
fn lerp_unclamped(from: Self, to: Self, factor: Self) -> Self
source§impl Lerp<f64> for f64
impl Lerp<f64> for f64
type Output = f64
fn lerp_unclamped_precise(from: Self, to: Self, factor: Self) -> Self
fn lerp_unclamped(from: Self, to: Self, factor: Self) -> Self
Implementors§
source§impl<'a, P, O, S, Factor> Lerp<Factor> for &'a Transform<P, O, S>
impl<'a, P, O, S, Factor> Lerp<Factor> for &'a Transform<P, O, S>
LERP on a Transform is defined as LERP-ing between the positions and scales,
and performing SLERP between the orientations.
source§impl<'a, T, Factor> Lerp<Factor> for &'a Quaternion<T>
impl<'a, T, Factor> Lerp<Factor> for &'a Quaternion<T>
The Lerp implementation for quaternion is the “Normalized LERP”.
type Output = Quaternion<T>
source§impl<P, O, S, Factor> Lerp<Factor> for Transform<P, O, S>
impl<P, O, S, Factor> Lerp<Factor> for Transform<P, O, S>
LERP on a Transform is defined as LERP-ing between the positions and scales,
and performing SLERP between the orientations.
source§impl<T, Factor> Lerp<Factor> for Quaternion<T>
impl<T, Factor> Lerp<Factor> for Quaternion<T>
The Lerp implementation for quaternion is the “Normalized LERP”.