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Move calculation in next_step() to SmoothingStyle

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Robbert van der Helm 2022-09-04 18:04:31 +02:00
parent a6d9972924
commit e47899d421
1 changed files with 24 additions and 11 deletions
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35
src/param/smoothing.rs
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@ -85,6 +85,29 @@ impl SmoothingStyle {
SmoothingStyle::Exponential(_) => 0.0001f64.powf(1.0 / steps_left as f64) as f32,
}
}
/// The same as [`next()`][Self::next()], but with the option to take more than one step at a
/// time. Calling `next_step()` with step count `n` gives the same result as applying `next()`
/// `n` times to a value, but is more efficient to compute. `next_step()` with 1 step is
/// equivalent to `step()`.
///
/// See the docstring on the [`SmoothingStyle::next_step()`] function for the formulas used.
#[inline]
pub fn next_step(&self, current: f32, target: f32, step_size: f32, steps: u32) -> f32 {
nih_debug_assert!(steps >= 1);
match self {
SmoothingStyle::None => target,
SmoothingStyle::Linear(_) => current + (step_size * steps as f32),
SmoothingStyle::Logarithmic(_) => current * (step_size.powi(steps as i32)),
SmoothingStyle::Exponential(_) => {
// This is the same as calculating `current = (current * step_size) +
// (target * (1 - step_size))` in a loop since the target value won't change
let coefficient = step_size.powi(steps as i32);
(current * coefficient) + (target * (1.0 - coefficient))
}
}
}
}
/// A type that can be smoothed. This exists just to avoid duplicate explicit implementations for
@ -221,17 +244,7 @@ impl<T: Smoothable> Smoother<T> {
self.steps_left.store(0, Ordering::Relaxed);
target
} else {
match &self.style {
SmoothingStyle::None => target,
SmoothingStyle::Linear(_) => current + (self.step_size * steps as f32),
SmoothingStyle::Logarithmic(_) => current * (self.step_size.powi(steps as i32)),
SmoothingStyle::Exponential(_) => {
// This is the same as calculating `current = (current * step_size) +
// (target * (1 - step_size))` in a loop since the target value won't change
let coefficient = self.step_size.powi(steps as i32);
(current * coefficient) + (target * (1.0 - coefficient))
}
}
self.style.next_step(current, target, self.step_size, steps)
};
self.current.store(new, Ordering::Relaxed);