use iced_core::Point;
use lyon::algorithms::measure::PathMeasurements;
use lyon::path::builder::NoAttributes;
use lyon::path::path::BuilderImpl;
use lyon::path::Path;
use once_cell::sync::Lazy;
pub static EMPHASIZED: Lazy<Easing> = Lazy::new(|| {
Easing::builder()
.cubic_bezier_to([0.05, 0.0], [0.133333, 0.06], [0.166666, 0.4])
.cubic_bezier_to([0.208333, 0.82], [0.25, 1.0], [1.0, 1.0])
.build()
});
pub static EMPHASIZED_DECELERATE: Lazy<Easing> = Lazy::new(|| {
Easing::builder()
.cubic_bezier_to([0.05, 0.7], [0.1, 1.0], [1.0, 1.0])
.build()
});
pub static EMPHASIZED_ACCELERATE: Lazy<Easing> = Lazy::new(|| {
Easing::builder()
.cubic_bezier_to([0.3, 0.0], [0.8, 0.15], [1.0, 1.0])
.build()
});
pub static STANDARD: Lazy<Easing> = Lazy::new(|| {
Easing::builder()
.cubic_bezier_to([0.2, 0.0], [0.0, 1.0], [1.0, 1.0])
.build()
});
pub static STANDARD_DECELERATE: Lazy<Easing> = Lazy::new(|| {
Easing::builder()
.cubic_bezier_to([0.0, 0.0], [0.0, 1.0], [1.0, 1.0])
.build()
});
pub static STANDARD_ACCELERATE: Lazy<Easing> = Lazy::new(|| {
Easing::builder()
.cubic_bezier_to([0.3, 0.0], [1.0, 1.0], [1.0, 1.0])
.build()
});
pub struct Easing {
path: Path,
measurements: PathMeasurements,
}
impl Easing {
pub fn builder() -> Builder {
Builder::new()
}
pub fn y_at_x(&self, x: f32) -> f32 {
let mut sampler = self.measurements.create_sampler(
&self.path,
lyon::algorithms::measure::SampleType::Normalized,
);
let sample = sampler.sample(x);
sample.position().y
}
}
pub struct Builder(NoAttributes<BuilderImpl>);
impl Builder {
pub fn new() -> Self {
let mut builder = Path::builder();
builder.begin(lyon::geom::point(0.0, 0.0));
Self(builder)
}
/// Adds a line segment. Points must be between 0,0 and 1,1
pub fn line_to(mut self, to: impl Into<Point>) -> Self {
self.0.line_to(Self::point(to));
self
}
/// Adds a quadratic bézier curve. Points must be between 0,0 and 1,1
pub fn quadratic_bezier_to(
mut self,
ctrl: impl Into<Point>,
to: impl Into<Point>,
) -> Self {
self.0
.quadratic_bezier_to(Self::point(ctrl), Self::point(to));
self
}
/// Adds a cubic bézier curve. Points must be between 0,0 and 1,1
pub fn cubic_bezier_to(
mut self,
ctrl1: impl Into<Point>,
ctrl2: impl Into<Point>,
to: impl Into<Point>,
) -> Self {
self.0.cubic_bezier_to(
Self::point(ctrl1),
Self::point(ctrl2),
Self::point(to),
);
self
}
pub fn build(mut self) -> Easing {
self.0.line_to(lyon::geom::point(1.0, 1.0));
self.0.end(false);
let path = self.0.build();
let measurements = PathMeasurements::from_path(&path, 0.0);
Easing { path, measurements }
}
fn point(p: impl Into<Point>) -> lyon::geom::Point<f32> {
let p: Point = p.into();
lyon::geom::point(p.x.min(1.0).max(0.0), p.y.min(1.0).max(0.0))
}
}
impl Default for Builder {
fn default() -> Self {
Self::new()
}
}
