to_css_linear

Samples an easing function into a CSS linear() easing, so that any curve (a Spring, a custom bounce) can be played by CSS transitions and the Web Animations API, which do not take code.

Values are rounded to 4 decimals. More samples follow the curve more closely, in a longer string; 32 is smooth for most springs.

Import

use helpers4::animation::to_css_linear;

Cargo feature animation (enabled by default). To compile only this module:

cargo add helpers4 --no-default-features --features animation

or in Cargo.toml:

[dependencies]
helpers4 = { version = "0.0.9", default-features = false, features = ["animation"] }

Signature

pub fn to_css_linear(easing: &dyn Fn(f64) -> f64, samples: u32) -> Option<String>

Parameters

Parameter	Type	Description
easing	&dyn Fn(f64) -> f64	The easing function over 0.0..=1.0.
samples	u32	Number of points, evenly spaced in time, at least 2.

Returns

Option<String> — A linear(...) string, or None when samples is less than 2.

Examples

use helpers4::animation::{to_css_linear, Spring};

assert_eq!(
    to_css_linear(&|t| t * t, 5).as_deref(),
    Some("linear(0, 0.0625, 0.25, 0.5625, 1)")
);

let spring = Spring::default();
let css = to_css_linear(&|t| spring.easing(t), 32);
assert!(css.is_some_and(|css| css.starts_with("linear(0, ")));

Source

src/animation/to_css_linear.rs