iir: more tweaking
use core::ops::{Add, Mul};
-use core::iter::Sum;
use core::f32;
@@ -25,10 +24,18 @@ fn copysign(x: f32, y: f32) -> f32 {
}
}
+fn max(x: f32, y: f32) -> f32 {
+ if x > y { x } else { y }
+}
+
+fn min(x: f32, y: f32) -> f32 {
+ if x < y { x } else { y }
+}
+
fn macc<T>(y0: T, x: &[T], a: &[T]) -> T
- where T: Sum + Add<Output=T> + Mul<Output=T> + Copy
+ where T: Add<Output=T> + Mul<Output=T> + Copy
{
- y0 + x.iter().zip(a.iter()).map(|(&i, &j)| i * j).sum()
+ x.iter().zip(a.iter()).map(|(&i, &j)| i * j).fold(y0, |y, xa| y + xa)
}
impl IIR {
@@ -74,8 +81,8 @@ impl IIR {
pub fn update(&self, xy: &mut IIRState, x0: f32) -> f32 {
xy.rotate_right(1);
xy[0] = x0;
- let y0 = macc(self.y_offset, xy, &self.ba)
- .max(self.y_min).min(self.y_max);
+ let y0 = macc(self.y_offset, xy, &self.ba);
+ let y0 = max(self.y_min, min(self.y_max, y0));
xy[xy.len()/2] = y0;
y0
}
