Added DaisySP

daisysp/Drums/hihat.h

@@ -0,0 +1,277 @@
+/*
+Copyright (c) 2020 Electrosmith, Corp, Emilie Gillet
+
+Use of this source code is governed by an MIT-style
+license that can be found in the LICENSE file or at
+https://opensource.org/licenses/MIT.
+*/
+
+#pragma once
+#ifndef DSY_HIHAT_H
+#define DSY_HIHAT_H
+
+#include "Filters/svf.h"
+#include "Synthesis/oscillator.h"
+
+#include <stdint.h>
+#include <stdlib.h>
+#ifdef __cplusplus
+
+/** @file hihat.h */
+
+namespace daisysp
+{
+/**  
+       @brief 808 style "metallic noise" with 6 square oscillators.
+       @author Ben Sergentanis
+       @date Jan 2021
+       Ported from pichenettes/eurorack/plaits/dsp/drums/hihat.h \n
+       to an independent module. \n
+       Original code written by Emilie Gillet in 2016. \n
+*/
+class SquareNoise
+{
+  public:
+    SquareNoise() {}
+    ~SquareNoise() {}
+
+    void Init(float sample_rate);
+
+    float Process(float f0);
+
+  private:
+    uint32_t phase_[6];
+};
+
+/**  
+       @brief Ring mod style metallic noise generator.
+       @author Ben Sergentanis
+       @date Jan 2021
+       Ported from pichenettes/eurorack/plaits/dsp/drums/hihat.h \n
+       to an independent module. \n
+       Original code written by Emilie Gillet in 2016. \n
+*/
+class RingModNoise
+{
+  public:
+    RingModNoise() {}
+    ~RingModNoise() {}
+
+    void Init(float sample_rate);
+
+    float Process(float f0);
+
+  private:
+    float      ProcessPair(Oscillator* osc, float f1, float f2);
+    Oscillator oscillator_[6];
+
+    float sample_rate_;
+};
+
+/**  
+       @brief Swing type VCA
+       @author Ben Sergentanis
+       @date Jan 2021
+       Ported from pichenettes/eurorack/plaits/dsp/drums/hihat.h \n
+       to an independent module. \n
+       Original code written by Emilie Gillet in 2016. \n
+*/
+class SwingVCA
+{
+  public:
+    float operator()(float s, float gain)
+    {
+        s *= s > 0.0f ? 10.0f : 0.1f;
+        s = s / (1.0f + fabsf(s));
+        return (s + 1.0f) * gain;
+    }
+};
+
+/**  
+       @brief Linear type VCA
+       @author Ben Sergentanis
+       @date Jan 2021
+       Ported from pichenettes/eurorack/plaits/dsp/drums/hihat.h \n
+       to an independent module. \n
+       Original code written by Emilie Gillet in 2016. \n
+*/
+class LinearVCA
+{
+  public:
+    float operator()(float s, float gain) { return s * gain; }
+};
+
+/**  
+       @brief 808 HH, with a few extra parameters to push things to the CY territory...
+       @author Ben Sergentanis
+       @date Jan 2021
+       The template parameter MetallicNoiseSource allows another kind of "metallic \n
+       noise" to be used, for results which are more similar to KR-55 or FM hi-hats. \n \n 
+       Ported from pichenettes/eurorack/plaits/dsp/drums/hihat.h \n
+       to an independent module. \n
+       Original code written by Emilie Gillet in 2016. \n
+*/
+template <typename MetallicNoiseSource = SquareNoise,
+          typename VCA                 = LinearVCA,
+          bool resonance               = true>
+class HiHat
+{
+  public:
+    HiHat() {}
+    ~HiHat() {}
+
+    /** Initialize the module
+        \param sample_rate Audio engine sample rate
+    */
+    void Init(float sample_rate)
+    {
+        sample_rate_ = sample_rate;
+
+        trig_ = false;
+
+        envelope_     = 0.0f;
+        noise_clock_  = 0.0f;
+        noise_sample_ = 0.0f;
+        sustain_gain_ = 0.0f;
+
+        SetFreq(3000.f);
+        SetTone(.5f);
+        SetDecay(.2f);
+        SetNoisiness(.8f);
+        SetAccent(.8f);
+        SetSustain(false);
+
+        metallic_noise_.Init(sample_rate_);
+        noise_coloration_svf_.Init(sample_rate_);
+        hpf_.Init(sample_rate_);
+    }
+
+    /** Get the next sample
+        \param trigger Hit the hihat with true. Defaults to false.
+    */
+    float Process(bool trigger = false)
+    {
+        const float envelope_decay
+            = 1.0f - 0.003f * SemitonesToRatio(-decay_ * 84.0f);
+        const float cut_decay
+            = 1.0f - 0.0025f * SemitonesToRatio(-decay_ * 36.0f);
+
+        if(trigger || trig_)
+        {
+            trig_ = false;
+
+            envelope_
+                = (1.5f + 0.5f * (1.0f - decay_)) * (0.3f + 0.7f * accent_);
+        }
+
+        // Process the metallic noise.
+        float out = metallic_noise_.Process(2.0f * f0_);
+
+        // Apply BPF on the metallic noise.
+        float cutoff = 150.0f / sample_rate_ * SemitonesToRatio(tone_ * 72.0f);
+
+        cutoff = fclamp(cutoff, 0.0f, 16000.0f / sample_rate_);
+
+
+        noise_coloration_svf_.SetFreq(cutoff * sample_rate_);
+        noise_coloration_svf_.SetRes(resonance ? 3.0f + 6.0f * tone_ : 1.0f);
+
+        noise_coloration_svf_.Process(out);
+        out = noise_coloration_svf_.Band();
+
+        // This is not at all part of the 808 circuit! But to add more variety, we
+        // add a variable amount of clocked noise to the output of the 6 schmitt
+        // trigger oscillators.
+        float noise_f = f0_ * (16.0f + 16.0f * (1.0f - noisiness_));
+        noise_f       = fclamp(noise_f, 0.0f, 0.5f);
+
+        noise_clock_ += noise_f;
+        if(noise_clock_ >= 1.0f)
+        {
+            noise_clock_ -= 1.0f;
+            noise_sample_ = rand() * kRandFrac - 0.5f;
+        }
+        out += noisiness_ * (noise_sample_ - out);
+
+        // Apply VCA.
+        sustain_gain_ = accent_ * decay_;
+        VCA vca;
+        envelope_ *= envelope_ > 0.5f ? envelope_decay : cut_decay;
+        out = vca(out, sustain_ ? sustain_gain_ : envelope_);
+
+        hpf_.SetFreq(cutoff * sample_rate_);
+        hpf_.SetRes(.5f);
+        hpf_.Process(out);
+        out = hpf_.High();
+
+        return out;
+    }
+
+    /** Trigger the hihat */
+    void Trig() { trig_ = true; }
+
+    /** Make the hihat ring out infinitely.
+        \param sustain True = infinite sustain.
+    */
+    void SetSustain(bool sustain) { sustain_ = sustain; }
+
+    /** Set how much accent to use
+        \param accent Works 0-1.
+    */
+    void SetAccent(float accent) { accent_ = fclamp(accent, 0.f, 1.f); }
+
+    /** Set the hihat tone's root frequency
+        \param f0 Freq in Hz
+    */
+    void SetFreq(float f0)
+    {
+        f0 /= sample_rate_;
+        f0_ = fclamp(f0, 0.f, 1.f);
+    }
+
+    /** Set the overall brightness / darkness of the hihat.
+        \param tone Works from 0-1.
+    */
+    void SetTone(float tone) { tone_ = fclamp(tone, 0.f, 1.f); }
+
+    /** Set the length of the hihat decay
+        \param decay Works > 0. Tuned for 0-1.
+    */
+    void SetDecay(float decay)
+    {
+        decay_ = fmax(decay, 0.f);
+        decay_ *= 1.7;
+        decay_ -= 1.2;
+    }
+
+    /** Sets the mix between tone and noise
+        \param snappy 1 = just noise. 0 = just tone.
+    */
+    void SetNoisiness(float noisiness)
+    {
+        noisiness_ = fclamp(noisiness, 0.f, 1.f);
+        noisiness_ *= noisiness_;
+    }
+
+
+  private:
+    float sample_rate_;
+
+    float accent_, f0_, tone_, decay_, noisiness_;
+    bool  sustain_;
+    bool  trig_;
+
+    float SemitonesToRatio(float in) { return powf(2.f, in * kOneTwelfth); }
+
+    float envelope_;
+    float noise_clock_;
+    float noise_sample_;
+    float sustain_gain_;
+
+    MetallicNoiseSource metallic_noise_;
+    Svf                 noise_coloration_svf_;
+    Svf                 hpf_;
+};
+} // namespace daisysp
+#endif
+#endif