translated some more dattorro code

src/dsp/dattorro.rs

@@ -8,6 +8,43 @@
 //
 // ValleyRackFree Copyright (C) 2020, Valley Audio Soft, Dale Johnson
 // Adapted under the GPL-3.0-or-later License.
+//
+// See also: https://github.com/ValleyAudio/ValleyRackFree/blob/v1.0/src/Plateau/Dattorro.cpp
+//      and: https://github.com/ValleyAudio/ValleyRackFree/blob/v1.0/src/Plateau/Dattorro.hpp
+//
+// And: https://ccrma.stanford.edu/~dattorro/music.html
+// And: https://ccrma.stanford.edu/~dattorro/EffectDesignPart1.pdf
+
+const DAT_SAMPLE_RATE    : f32 = 29761.0;
+const DAT_SAMPLES_PER_MS : f32 = DAT_SAMPLE_RATE / 1000.0;
+
+const DAT_INPUT_APF_TIMES_MS : [f32; 4] = [
+    141.0 / DAT_SAMPLES_PER_MS,
+    107.0 / DAT_SAMPLES_PER_MS,
+    379.0 / DAT_SAMPLES_PER_MS,
+    277.0 / DAT_SAMPLES_PER_MS,
+];
+
+const DAT_LEFT_APF1_TIME_MS  : f32 = 672.0  / DAT_SAMPLES_PER_MS;
+const DAT_LEFT_APF2_TIME_MS  : f32 = 1800.0 / DAT_SAMPLES_PER_MS;
+
+const DAT_RIGHT_APF1_TIME_MS : f32 = 908.0  / DAT_SAMPLES_PER_MS;
+const DAT_RIGHT_APF2_TIME_MS : f32 = 2656.0 / DAT_SAMPLES_PER_MS;
+
+//    const long _kLeftApf1Time = 672;
+//    const long _kLeftDelay1Time = 4453;
+//    const long _kLeftApf2Time = 1800;
+//    const long _kLeftDelay2Time = 3720;
+//
+//    const long _kRightApf1Time = 908;
+//    const long _kRightDelay1Time = 4217;
+//    const long _kRightApf2Time = 2656;
+//    const long _kRightDelay2Time = 3163;
+
+const DAT_INPUT_DIFFUSION1 : f32 = 0.75;
+const DAT_INPUT_DIFFUSION2 : f32 = 0.625;
+const DAT_PLATE_DIFFUSION1 : f32 = 0.7;
+const DAT_PLATE_DIFFUSION2 : f32 = 0.5;
 
 use crate::dsp::helpers::{
     AllPass,
@@ -19,6 +56,8 @@ use crate::dsp::helpers::{
 };
 
 pub struct DattorroReverb {
+    last_scale: f32,
+
     inp_dc_block:   [DCBlockFilter; 2],
     out_dc_block:   [DCBlockFilter; 2],
 
@@ -28,12 +67,82 @@ pub struct DattorroReverb {
     input_lpf: OnePoleLPF,
 
     pre_delay:  DelayBuffer,
-    input_apfs: [AllPass; 4],
+    input_apfs: [(AllPass, f32); 4],
 
-    apf1:   [AllPass; 2],
+    apf1:   [(AllPass, f32); 2],
     hpf:    [OnePoleHPF; 2],
     lpf:    [OnePoleLPF; 2],
     apf2:   [AllPass; 2],
     delay1: [DelayBuffer; 2],
     delay2: [DelayBuffer; 2],
+
+    time_scale_factor: f32,
+}
+
+pub trait DattorroReverbParams {
+    /// Time for the pre-delay of the reverb.
+    fn pre_delay_time_s(&self) -> f32;
+}
+
+impl DattorroReverb {
+    pub fn new() -> Self {
+        let mut this = Self {
+            last_scale: 1.0,
+
+            inp_dc_block:   [DCBlockFilter::new(); 2],
+            out_dc_block:   [DCBlockFilter::new(); 2],
+
+            lfos: [TriSawLFO::new(); 4],
+
+            input_hpf: OnePoleHPF::new(),
+            input_lpf: OnePoleLPF::new(),
+
+            pre_delay:  DelayBuffer::new(),
+            input_apfs: [(AllPass::new(), 0.0); 4],
+
+            apf1:   [(AllPass::new(), 0.0); 2],
+            hpf:    [OnePoleHPF::new(); 2],
+            lpf:    [OnePoleLPF::new(); 2],
+            apf2:   [AllPass::new(); 2],
+            delay1: [DelayBuffer::new(); 2],
+            delay2: [DelayBuffer::new(); 2],
+            time_scale_factor: 1.0,
+        };
+
+        this.reset();
+
+        this
+    }
+
+    pub fn reset(&mut self) {
+        self.input_lpf.set_freq(22000.0);
+        self.input_hpf.set_freq(0.0);
+
+        self.input_apfs[0].1 = DAT_INPUT_APF_TIMES_MS[0];
+        self.input_apfs[1].1 = DAT_INPUT_APF_TIMES_MS[1];
+        self.input_apfs[2].1 = DAT_INPUT_APF_TIMES_MS[2];
+        self.input_apfs[3].1 = DAT_INPUT_APF_TIMES_MS[3];
+
+        self.set_time_scale(1.0);
+    }
+
+    #[inline]
+    pub fn set_time_scale(&mut self, scale: f32) {
+        if (self.last_scale - scale).abs() > std::f32::consts::EPSILON {
+            let scale = scale.max(0.0001);
+            self.last_scale = scale;
+
+            self.apf1[0].1 = DAT_LEFT_APF1_TIME_MS  * scale;
+            self.apf1[1].1 = DAT_RIGHT_APF1_TIME_MS * scale;
+            self.apf2[0].1 = DAT_LEFT_APF2_TIME_MS  * scale;
+            self.apf2[1].1 = DAT_RIGHT_APF2_TIME_MS * scale;
+        }
+    }
+
+    pub fn set_sample_rate(&mut self, srate: f32) {
+        self.time_scale_factor = srate / DAT_SAMPLE_RATE;
+    }
+
+    pub fn process(&mut self, params: &mut dyn DattorroReverbParams, input: f32) -> (f32, f32) {
+    }
 }