Add hardness parameter to Clip.

CHANGES.md

@@ -9,6 +9,7 @@
 - Clarified latency: it only applies to involuntary causal latencies.
 - `AdaptiveTanh` is now generic `Adaptive` distortion with an inner shape.
   To migrate, try `Adaptive::new(timescale, Tanh(hardness))`.
+- `Clip` shape now has a hardness parameter. `Clip(1.0)` to migrate.
 
 ### Version 0.18.2
 

README.md

@@ -1256,18 +1256,19 @@ let partials = busf::<U20, _, _>(|f| noise() >> resonator_hz(xerp(1_000.0, 2_000
 
 #### Waveshaping Modes
 
-These are arguments to the `shape` opcode.
+These are arguments to the `shape` opcode. Shapes `Atan`, `Clip`, `Softsign` and `Tanh`
+all have a slope of 1 at the origin when hardness is 1 and saturate in the range -1...1.
 
-- `Clip`: Clip signal to -1...1.
-- `ClipTo(minimum, maximum)`: Clip signal between the two arguments.
-- `Tanh(hardness)`: Apply `tanh` distortion with configurable hardness. Argument to `tanh` is multiplied by the hardness value.
+- `Adaptive::new(timescale, inner)`: Apply adaptive normalizing distortion with smoothing `timescale` in seconds.
+Smoothing timescale is the time it takes for level estimation to move halfway to a new value.
+The argument to the `inner` shape is divided by the RMS level of the signal.
 - `Atan(hardness)`: Apply `atan` distortion with configurable hardness, with the output range scaled to -1...1. Argument to `atan` is multiplied by the hardness value.
-- `Softsign(hardness)`: Apply `softsign` distortion with configurable hardness. Argument to `softsign` is multiplied by the hardness value.
+- `Clip(hardness)`: Multiply signal with hardness and then clamp it to -1...1.
+- `ClipTo(minimum, maximum)`: Clip signal between the two arguments.
 - `Crush(levels)`: Apply a staircase function with configurable number of levels per unit.
 - `SoftCrush(levels)`: Apply a smooth staircase function with configurable number of levels per unit.
-- `AdaptiveTanh::new(timescale, hardness)`: Apply adaptive normalizing distortion with smoothing `timescale` in seconds.
-Smoothing timescale is the time it takes for level estimation to move halfway to a new value.
-Argument to `tanh` is multiplied by the hardness value and divided by the RMS level of the signal.
+- `Softsign(hardness)`: Apply `softsign` distortion with configurable hardness. Argument to `softsign` is multiplied by the hardness value.
+- `Tanh(hardness)`: Apply `tanh` distortion with configurable hardness. Argument to `tanh` is multiplied by the hardness value.
 
 #### Metering Modes
 

src/hacker.rs

@@ -1170,7 +1170,7 @@ pub fn shape<S: Shape>(mode: S) -> An<Shaper<S>> {
 /// - Input 0: input signal
 /// - Output 0: clipped signal
 pub fn clip() -> An<Shaper<Clip>> {
-    An(Shaper::new(Clip))
+    An(Shaper::new(Clip(1.0)))
 }
 
 /// Clip signal to `minimum`...`maximum`.

src/hacker32.rs

@@ -1170,7 +1170,7 @@ pub fn shape<S: Shape>(mode: S) -> An<Shaper<S>> {
 /// - Input 0: input signal
 /// - Output 0: clipped signal
 pub fn clip() -> An<Shaper<Clip>> {
-    An(Shaper::new(Clip))
+    An(Shaper::new(Clip(1.0)))
 }
 
 /// Clip signal to `minimum`...`maximum`.

src/prelude.rs

@@ -1184,7 +1184,7 @@ pub fn shape<S: Shape>(mode: S) -> An<Shaper<S>> {
 /// - Input 0: input signal
 /// - Output 0: clipped signal
 pub fn clip() -> An<Shaper<Clip>> {
-    An(Shaper::new(Clip))
+    An(Shaper::new(Clip(1.0)))
 }
 
 /// Clip signal to `minimum`...`maximum`.

src/shape.rs

@@ -45,16 +45,16 @@ impl<S: Fn(f32) -> f32 + Clone + Sync + Send> Shape for ShapeFn<S> {
 
 /// Clip signal to -1...1.
 #[derive(Clone)]
-pub struct Clip;
+pub struct Clip(pub f32);
 
 impl Shape for Clip {
     #[inline]
     fn shape(&mut self, input: f32) -> f32 {
-        input.clamp(-1.0, 1.0)
+        (input * self.0).clamp(-1.0, 1.0)
     }
     #[inline]
     fn simd(&mut self, input: F32x) -> F32x {
-        input.fast_max(-F32x::ONE).fast_min(F32x::ONE)
+        (input * self.0).fast_max(-F32x::ONE).fast_min(F32x::ONE)
     }
 }