digital_svf.h

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#pragma once
 
#include "processor.h"
#include "synth_filter.h"
 
namespace vital {
 
  class DigitalSvf : public Processor, public SynthFilter {
    public:
      static constexpr mono_float kDefaultMinResonance = 0.5f;
 
      static constexpr mono_float kDefaultMaxResonance = 16.0f;
 
      static constexpr mono_float kMinCutoff = 1.0f;
 
      static constexpr mono_float kMaxGain = 15.0f;
 
      static constexpr mono_float kMinGain = -15.0f;
 
      static force_inline mono_float computeSvfOnePoleFilterCoefficient(mono_float frequency_ratio) {
        static constexpr float kMaxRatio = 0.499f;
        return std::tan(std::min(kMaxRatio, frequency_ratio) * vital::kPi);
      }
 
      typedef OneDimLookup<computeSvfOnePoleFilterCoefficient, 2048> SvfCoefficientLookup;
 
      static const SvfCoefficientLookup svf_coefficient_lookup_;
 
      static const SvfCoefficientLookup* getSvfCoefficientLookup() { return &svf_coefficient_lookup_; }
 
      struct FilterValues {
        poly_float v0; 
        poly_float v1; 
        poly_float v2; 
 
        void hardReset() {
          v0 = 0.0f;
          v1 = 0.0f;
          v2 = 0.0f;
        }
 
        void reset(poly_mask reset_mask, const FilterValues& other) {
          v0 = utils::maskLoad(v0, other.v0, reset_mask);
          v1 = utils::maskLoad(v1, other.v1, reset_mask);
          v2 = utils::maskLoad(v2, other.v2, reset_mask);
        }
 
        FilterValues getDelta(const FilterValues& target, mono_float increment) {
          FilterValues result;
          result.v0 = (target.v0 - v0) * increment;
          result.v1 = (target.v1 - v1) * increment;
          result.v2 = (target.v2 - v2) * increment;
          return result;
        }
 
        force_inline void increment(const FilterValues& delta) {
          v0 += delta.v0;
          v1 += delta.v1;
          v2 += delta.v2;
        }
      };
 
      DigitalSvf();
 
      virtual ~DigitalSvf() { }
 
      virtual Processor* clone() const override { return new DigitalSvf(*this); }
 
      virtual void process(int num_samples) override;
 
      void processWithInput(const poly_float* audio_in, int num_samples) override;
 
      void reset(poly_mask reset_masks) override;
 
      void hardReset() override;
 
      void setupFilter(const FilterState& filter_state) override;
 
      void setResonanceBounds(mono_float min, mono_float max);
 
      void process12(const poly_float* audio_in, int num_samples,
                     poly_float current_resonance, poly_float current_drive,
                     poly_float current_post_multiply, FilterValues& blends);
 
      void processBasic12(const poly_float* audio_in, int num_samples,
                          poly_float current_resonance, poly_float current_drive,
                          poly_float current_post_multiply, FilterValues& blends);
 
      void process24(const poly_float* audio_in, int num_samples,
                     poly_float current_resonance, poly_float current_drive,
                     poly_float current_post_multiply, FilterValues& blends);
 
      void processBasic24(const poly_float* audio_in, int num_samples,
                          poly_float current_resonance, poly_float current_drive,
                          poly_float current_post_multiply, FilterValues& blends);
 
      void processDual(const poly_float* audio_in, int num_samples,
                       poly_float current_resonance, poly_float current_drive,
                       poly_float current_post_multiply,
                       FilterValues& blends1, FilterValues& blends2);
 
      force_inline poly_float tick(poly_float audio_in, poly_float coefficient,
                                   poly_float resonance, poly_float drive, FilterValues& blends);
 
      force_inline poly_float tickBasic(poly_float audio_in, poly_float coefficient,
                                        poly_float resonance, poly_float drive, FilterValues& blends);
 
      force_inline poly_float tick24(poly_float audio_in, poly_float coefficient,
                                     poly_float resonance, poly_float drive, FilterValues& blends);
 
      force_inline poly_float tickBasic24(poly_float audio_in, poly_float coefficient,
                                          poly_float resonance, poly_float drive, FilterValues& blends);
 
      force_inline poly_float tickDual(poly_float audio_in, poly_float coefficient,
                                       poly_float resonance, poly_float drive,
                                       FilterValues& blends1, FilterValues& blends2);
 
      poly_float getDrive() const { return drive_ * post_multiply_; }
 
      poly_float getMidiCutoff() const { return midi_cutoff_; }
 
      poly_float getResonance() const { return resonance_; }
 
      poly_float getLowAmount() const { return low_amount_; }
 
      poly_float getBandAmount() const { return band_amount_; }
 
      poly_float getHighAmount() const { return high_amount_; }
 
      poly_float getLowAmount24(int style) const {
        if (style == kDualNotchBand)
          return high_amount_;
        return low_amount_;
      }
 
      poly_float getHighAmount24(int style) const {
        if (style == kDualNotchBand)
          return low_amount_;
        return high_amount_;
      }
 
      void setBasic(bool basic) { basic_ = basic; }
 
      void setDriveCompensation(bool drive_compensation) { drive_compensation_ = drive_compensation; }
 
    private:
      poly_float midi_cutoff_;
 
      poly_float resonance_;
 
      FilterValues blends1_;
 
      FilterValues blends2_;
 
      poly_float drive_;
 
      poly_float post_multiply_;
 
      poly_float low_amount_;
 
      poly_float band_amount_;
 
      poly_float high_amount_;
 
      poly_float ic1eq_pre_, ic2eq_pre_;
 
      poly_float ic1eq_, ic2eq_;
 
      mono_float min_resonance_;
 
      mono_float max_resonance_;
 
      bool basic_;
 
      bool drive_compensation_;
 
      JUCE_LEAK_DETECTOR(DigitalSvf)
  };
} // namespace vital