Introduce the concept of SampledWithKey.

This allows to type more correctly the output of the `*_with_key`
functions.
This commit is contained in:
Dimitri Sabadie 2021-02-27 23:38:54 +01:00
parent 469a785767
commit 395dff34ee
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GPG Key ID: B313786A66884DCD
2 changed files with 51 additions and 22 deletions

View File

@ -102,7 +102,7 @@ impl<T, V> Spline<T, V> {
/// sampling impossible. For instance, [`Interpolation::CatmullRom`] requires *four* keys. If /// sampling impossible. For instance, [`Interpolation::CatmullRom`] requires *four* keys. If
/// youre near the beginning of the spline or its end, ensure you have enough keys around to make /// youre near the beginning of the spline or its end, ensure you have enough keys around to make
/// the sampling. /// the sampling.
pub fn sample_with_key(&self, t: T) -> Option<(V, &Key<T, V>, Option<&Key<T, V>>)> pub fn sample_with_key(&self, t: T) -> Option<SampledWithKey<V>>
where where
T: Additive + One + Trigo + Mul<T, Output = T> + Div<T, Output = T> + PartialOrd, T: Additive + One + Trigo + Mul<T, Output = T> + Div<T, Output = T> + PartialOrd,
V: Additive + Interpolate<T>, V: Additive + Interpolate<T>,
@ -111,13 +111,13 @@ impl<T, V> Spline<T, V> {
let i = search_lower_cp(keys, t)?; let i = search_lower_cp(keys, t)?;
let cp0 = &keys[i]; let cp0 = &keys[i];
match cp0.interpolation { let value = match cp0.interpolation {
Interpolation::Step(threshold) => { Interpolation::Step(threshold) => {
let cp1 = &keys[i + 1]; let cp1 = &keys[i + 1];
let nt = normalize_time(t, cp0, cp1); let nt = normalize_time(t, cp0, cp1);
let value = if nt < threshold { cp0.value } else { cp1.value }; let value = if nt < threshold { cp0.value } else { cp1.value };
Some((value, cp0, Some(cp1))) Some(value)
} }
Interpolation::Linear => { Interpolation::Linear => {
@ -125,7 +125,7 @@ impl<T, V> Spline<T, V> {
let nt = normalize_time(t, cp0, cp1); let nt = normalize_time(t, cp0, cp1);
let value = Interpolate::lerp(cp0.value, cp1.value, nt); let value = Interpolate::lerp(cp0.value, cp1.value, nt);
Some((value, cp0, Some(cp1))) Some(value)
} }
Interpolation::Cosine => { Interpolation::Cosine => {
@ -135,7 +135,7 @@ impl<T, V> Spline<T, V> {
let cos_nt = (T::one() - (nt * T::pi()).cos()) / two_t; let cos_nt = (T::one() - (nt * T::pi()).cos()) / two_t;
let value = Interpolate::lerp(cp0.value, cp1.value, cos_nt); let value = Interpolate::lerp(cp0.value, cp1.value, cos_nt);
Some((value, cp0, Some(cp1))) Some(value)
} }
Interpolation::CatmullRom => { Interpolation::CatmullRom => {
@ -156,7 +156,7 @@ impl<T, V> Spline<T, V> {
nt, nt,
); );
Some((value, cp0, Some(cp1))) Some(value)
} }
} }
@ -177,9 +177,11 @@ impl<T, V> Spline<T, V> {
_ => Interpolate::quadratic_bezier(cp0.value, u, cp1.value, nt), _ => Interpolate::quadratic_bezier(cp0.value, u, cp1.value, nt),
}; };
Some((value, cp0, Some(cp1))) Some(value)
} }
} };
value.map(|value| SampledWithKey { value, key: i })
} }
/// Sample a spline at a given time. /// Sample a spline at a given time.
@ -189,7 +191,7 @@ impl<T, V> Spline<T, V> {
T: Additive + One + Trigo + Mul<T, Output = T> + Div<T, Output = T> + PartialOrd, T: Additive + One + Trigo + Mul<T, Output = T> + Div<T, Output = T> + PartialOrd,
V: Additive + Interpolate<T>, V: Additive + Interpolate<T>,
{ {
self.sample_with_key(t).map(|(v, _, _)| v) self.sample_with_key(t).map(|sampled| sampled.value)
} }
/// Sample a spline at a given time with clamping, returning the interpolated value along with its /// Sample a spline at a given time with clamping, returning the interpolated value along with its
@ -203,7 +205,7 @@ impl<T, V> Spline<T, V> {
/// # Error /// # Error
/// ///
/// This function returns [`None`] if you have no key. /// This function returns [`None`] if you have no key.
pub fn clamped_sample_with_key(&self, t: T) -> Option<(V, &Key<T, V>, Option<&Key<T, V>>)> pub fn clamped_sample_with_key(&self, t: T) -> Option<SampledWithKey<V>>
where where
T: Additive + One + Trigo + Mul<T, Output = T> + Div<T, Output = T> + PartialOrd, T: Additive + One + Trigo + Mul<T, Output = T> + Div<T, Output = T> + PartialOrd,
V: Additive + Interpolate<T>, V: Additive + Interpolate<T>,
@ -214,18 +216,22 @@ impl<T, V> Spline<T, V> {
self.sample_with_key(t).or_else(move || { self.sample_with_key(t).or_else(move || {
let first = self.0.first().unwrap(); let first = self.0.first().unwrap();
if t <= first.t { if t <= first.t {
let second = if self.0.len() >= 2 { let sampled = SampledWithKey {
Some(&self.0[1]) value: first.value,
} else { key: 0,
None
}; };
Some((first.value, &first, second)) Some(sampled)
} else { } else {
let last = self.0.last().unwrap(); let last = self.0.last().unwrap();
if t >= last.t { if t >= last.t {
Some((last.value, &last, None)) let sampled = SampledWithKey {
value: last.value,
key: self.0.len() - 1,
};
Some(sampled)
} else { } else {
None None
} }
@ -239,7 +245,7 @@ impl<T, V> Spline<T, V> {
T: Additive + One + Trigo + Mul<T, Output = T> + Div<T, Output = T> + PartialOrd, T: Additive + One + Trigo + Mul<T, Output = T> + Div<T, Output = T> + PartialOrd,
V: Additive + Interpolate<T>, V: Additive + Interpolate<T>,
{ {
self.clamped_sample_with_key(t).map(|(v, _, _)| v) self.clamped_sample_with_key(t).map(|sampled| sampled.value)
} }
/// Add a key into the spline. /// Add a key into the spline.
@ -293,11 +299,22 @@ impl<T, V> Spline<T, V> {
} }
} }
/// A sampled value along with its key index.
#[derive(Clone, Debug, Eq, Hash, PartialEq)]
pub struct SampledWithKey<V> {
/// Sampled value.
pub value: V,
/// Key index.
pub key: usize,
}
/// A mutable [`Key`]. /// A mutable [`Key`].
/// ///
/// Mutable keys allow to edit the carried values and the interpolation mode but not the actual /// Mutable keys allow to edit the carried values and the interpolation mode but not the actual
/// interpolator value as it would invalidate the internal structure of the [`Spline`]. If you /// interpolator value as it would invalidate the internal structure of the [`Spline`]. If you
/// want to achieve this, youre advised to use [`Spline::replace`]. /// want to achieve this, youre advised to use [`Spline::replace`].
#[derive(Debug)]
pub struct KeyMut<'a, T, V> { pub struct KeyMut<'a, T, V> {
/// Carried value. /// Carried value.
pub value: &'a mut V, pub value: &'a mut V,

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@ -1,4 +1,4 @@
use splines::{Interpolation, Key, Spline}; use splines::{spline::SampledWithKey, Interpolation, Key, Spline};
#[cfg(feature = "cgmath")] #[cfg(feature = "cgmath")]
use cgmath as cg; use cgmath as cg;
@ -18,8 +18,14 @@ fn step_interpolation_f32() {
assert_eq!(spline.sample(0.9), Some(10.)); assert_eq!(spline.sample(0.9), Some(10.));
assert_eq!(spline.sample(1.), None); assert_eq!(spline.sample(1.), None);
assert_eq!(spline.clamped_sample(1.), Some(10.)); assert_eq!(spline.clamped_sample(1.), Some(10.));
assert_eq!(spline.sample_with_key(0.2), Some((10., &start, Some(&end)))); assert_eq!(
assert_eq!(spline.clamped_sample_with_key(1.), Some((10., &end, None))); spline.sample_with_key(0.2),
Some(SampledWithKey { value: 10., key: 0 })
);
assert_eq!(
spline.clamped_sample_with_key(1.),
Some(SampledWithKey { value: 10., key: 1 })
);
} }
#[test] #[test]
@ -35,8 +41,14 @@ fn step_interpolation_f64() {
assert_eq!(spline.sample(0.9), Some(10.)); assert_eq!(spline.sample(0.9), Some(10.));
assert_eq!(spline.sample(1.), None); assert_eq!(spline.sample(1.), None);
assert_eq!(spline.clamped_sample(1.), Some(10.)); assert_eq!(spline.clamped_sample(1.), Some(10.));
assert_eq!(spline.sample_with_key(0.2), Some((10., &start, Some(&end)))); assert_eq!(
assert_eq!(spline.clamped_sample_with_key(1.), Some((10., &end, None))); spline.sample_with_key(0.2),
Some(SampledWithKey { value: 10., key: 0 })
);
assert_eq!(
spline.clamped_sample_with_key(1.),
Some(SampledWithKey { value: 10., key: 1 })
);
} }
#[test] #[test]