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Reach 99.99% of target for exponential smoothing

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Instead of 99.97%. Both numbers are not based on anything, but this
calculation makes more sense.
This commit is contained in:
Robbert van der Helm 2022-05-12 13:21:32 +02:00
parent 28c7ea4843
commit dc5dfb06c6
1 changed files with 5 additions and 5 deletions
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10
src/param/smoothing.rs
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@ -24,7 +24,7 @@ pub enum SmoothingStyle {
/// Smooth parameter changes such that the rate matches the curve of an exponential function, /// Smooth parameter changes such that the rate matches the curve of an exponential function,
/// starting out fast and then tapering off until the end. This is a single-pole IIR filter /// starting out fast and then tapering off until the end. This is a single-pole IIR filter
/// under the hood, while the other smoothing options are FIR filters. This means that the exact /// under the hood, while the other smoothing options are FIR filters. This means that the exact
/// value would never be reached. Instead, this reaches 99.97% of the value target value in the /// value would never be reached. Instead, this reaches 99.99% of the value target value in the
/// specified number of milliseconds, and it then snaps to the target value in the last step. /// specified number of milliseconds, and it then snaps to the target value in the last step.
/// This results in a smoother transition, with the caveat being that there will be a tiny jump /// This results in a smoother transition, with the caveat being that there will be a tiny jump
/// at the end. Unlike the `Logarithmic` option, this does support crossing the zero value. /// at the end. Unlike the `Logarithmic` option, this does support crossing the zero value.
@ -186,9 +186,9 @@ impl Smoother<f32> {
} }
// In this case the step size value is the coefficient the current value will be // 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 // multiplied by, while the target value is multipled by one minus the coefficient. This
// reaches 99.97% of the target value after `steps_left`. The smoother will snap to the // reaches 99.99% of the target value after `steps_left`. The smoother will snap to the
// target value after that point. // target value after that point.
SmoothingStyle::Exponential(_) => (-8.0 / steps_left as f32).exp(), SmoothingStyle::Exponential(_) => 0.0001f32.powf(-1.0 / steps_left as f32),
}; };
} }
@ -275,7 +275,7 @@ impl Smoother<f32> {
SmoothingStyle::Logarithmic(_) => current * (self.step_size.powi(steps as i32)), SmoothingStyle::Logarithmic(_) => current * (self.step_size.powi(steps as i32)),
SmoothingStyle::Exponential(_) => { SmoothingStyle::Exponential(_) => {
// This is the same as calculating `current = (current * step_size) + // This is the same as calculating `current = (current * step_size) +
// (target * (1 - step_size))` in a loop // (target * (1 - step_size))` in a loop since the target value won't change
let coefficient = self.step_size.powi(steps as i32); let coefficient = self.step_size.powi(steps as i32);
(current * coefficient) + (self.target * (1.0 - coefficient)) (current * coefficient) + (self.target * (1.0 - coefficient))
} }
@ -317,7 +317,7 @@ impl Smoother<i32> {
nih_debug_assert_ne!(current, 0.0); nih_debug_assert_ne!(current, 0.0);
(self.target as f32 / current).powf((steps_left as f32).recip()) (self.target as f32 / current).powf((steps_left as f32).recip())
} }
SmoothingStyle::Exponential(_) => (-8.0 / steps_left as f32).exp(), SmoothingStyle::Exponential(_) => 0.0001f32.powf(-1.0 / steps_left as f32),
}; };
} }