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Move the smoothing step size to a function

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This commit is contained in:
Robbert van der Helm 2022-09-04 17:50:42 +02:00
parent 67496f9c79
commit a6d9972924
1 changed files with 27 additions and 15 deletions
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42
src/param/smoothing.rs
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@ -63,6 +63,30 @@ pub struct SmootherIter<'a, T> {
smoother: &'a Smoother<T>,
}
impl SmoothingStyle {
/// Compute the step size for this smoother.
#[inline]
pub fn step_size(&self, current: f32, target: f32, steps_left: u32) -> f32 {
nih_debug_assert!(steps_left >= 1);
match self {
SmoothingStyle::None => 0.0,
SmoothingStyle::Linear(_) => (target - current) / (steps_left as f32),
SmoothingStyle::Logarithmic(_) => {
// We need to solve `current * (step_size ^ steps_left) = target` for
// `step_size`
nih_debug_assert_ne!(current, 0.0);
((target / current) as f64).powf((steps_left as f64).recip()) as f32
}
// In this case the step size value is the coefficient the current value will be
// multiplied by, while the target value is multipled by one minus the coefficient. This
// reaches 99.99% of the target value after `steps_left`. The smoother will snap to the
// target value after that point.
SmoothingStyle::Exponential(_) => 0.0001f64.powf(1.0 / steps_left as f64) as f32,
}
}
}
/// A type that can be smoothed. This exists just to avoid duplicate explicit implementations for
/// the smoothers.
pub trait Smoothable: Default + Copy {
@ -161,21 +185,9 @@ impl<T: Smoothable> Smoother<T> {
self.steps_left.store(steps_left, Ordering::Relaxed);
let current = self.current.load(Ordering::Relaxed);
self.step_size = match self.style {
SmoothingStyle::None => 0.0,
SmoothingStyle::Linear(_) => (self.target.to_f32() - current) / steps_left as f32,
SmoothingStyle::Logarithmic(_) => {
// We need to solve `current * (step_size ^ steps_left) = target` for
// `step_size`
nih_debug_assert_ne!(current, 0.0);
((self.target.to_f32() / current) as f64).powf((steps_left as f64).recip()) as f32
}
// In this case the step size value is the coefficient the current value will be
// multiplied by, while the target value is multipled by one minus the coefficient. This
// reaches 99.99% of the target value after `steps_left`. The smoother will snap to the
// target value after that point.
SmoothingStyle::Exponential(_) => 0.0001f64.powf(1.0 / steps_left as f64) as f32,
};
self.step_size = self
.style
.step_size(current, self.target.to_f32(), steps_left as u32);
}
/// Get the next value from this smoother. The value will be equal to the previous value once