Line data    Source code

       1             : /**
       2             :  * \file SecondOrderSVFFilter.h
       3             :  * Inspired by http://www.cytomic.com/files/dsp/SvfLinearTrapOptimised2.pdf
       4             :  */
       5             : 
       6             : #ifndef ATK_EQ_SECONDORDERSVFFILTER_H
       7             : #define ATK_EQ_SECONDORDERSVFFILTER_H
       8             : 
       9             : #include <ATK/EQ/config.h>
      10             : #include <ATK/Core/TypedBaseFilter.h>
      11             : 
      12             : namespace ATK
      13             : {
      14             :   /// Second order SVF main filter class
      15             :   template<typename SVFCoefficients>
      16          36 :   class ATK_EQ_EXPORT SecondOrderSVFFilter final: public SVFCoefficients
      17             :   {
      18             :   protected:
      19             :     using Parent = SVFCoefficients;
      20             :     using typename Parent::AlignedScalarVector;
      21             :     using typename Parent::DataType;
      22             :     using typename Parent::CoeffDataType;
      23             :     using Parent::converted_inputs;
      24             :     using Parent::outputs;
      25             :     using Parent::nb_input_ports;
      26             :     using Parent::nb_output_ports;
      27             :     using Parent::a1;
      28             :     using Parent::a2;
      29             :     using Parent::a3;
      30             :     using Parent::m0;
      31             :     using Parent::m1;
      32             :     using Parent::m2;
      33             : 
      34             :   public:
      35             :     explicit SecondOrderSVFFilter(gsl::index nb_channels = 1);
      36             :     ~SecondOrderSVFFilter() override;
      37             :     
      38             :     void full_setup() final;
      39             :   protected:
      40             :     void process_impl(gsl::index size) const final;
      41             : 
      42             :     class SVFState;
      43             :     std::unique_ptr<SVFState[]> state;
      44             :   };
      45             : 
      46             :   /// Second order SVF base coefficient class
      47             :   template<typename DataType_>
      48             :   class SecondOrderSVFBaseCoefficients : public TypedBaseFilter<DataType_>
      49             :   {
      50             :   public:
      51             :     using Parent = TypedBaseFilter<DataType_>;
      52             :     using typename Parent::DataType;
      53             :     using CoeffDataType = typename TypeTraits<DataType>::Scalar;
      54             :     using Parent::setup;
      55             :   protected:
      56             :     CoeffDataType cut_frequency{0};
      57             :     CoeffDataType Q{1};
      58             : 
      59             :     CoeffDataType a1{0};
      60             :     CoeffDataType a2{0};
      61             :     CoeffDataType a3{0};
      62             :     CoeffDataType m0{0};
      63             :     CoeffDataType m1{0};
      64             :     CoeffDataType m2{0};
      65             : 
      66             :   public:
      67             :     explicit SecondOrderSVFBaseCoefficients(gsl::index nb_channels);
      68             : 
      69             :     /// Sets the cut or central frequency of the filter
      70             :     void set_cut_frequency(CoeffDataType cut_frequency);
      71             :     /// Returns the cut or central frequency
      72             :     CoeffDataType get_cut_frequency() const;
      73             :     /// Sets the Q factor, must be strictly positive
      74             :     /*!
      75             :     * A smaller Q will lead to a bigger bandwidth, a bigger Q will lead to a smaller bandwidth
      76             :     */
      77             :     void set_Q(CoeffDataType Q);
      78             :     /// Returns the Q factor
      79             :     CoeffDataType get_Q() const;
      80             :   };
      81             : 
      82             :   /// Coefficients for a second order SVF low-pass filter
      83             :   template<typename DataType_>
      84             :   class SecondOrderSVFLowPassCoefficients : public SecondOrderSVFBaseCoefficients<DataType_>
      85             :   {
      86             :   public:
      87             :     using Parent = SecondOrderSVFBaseCoefficients<DataType_>;
      88             :     using typename Parent::DataType;
      89             :     using typename Parent::CoeffDataType;
      90             :     using Parent::setup;
      91             :     using Parent::a1;
      92             :     using Parent::a2;
      93             :     using Parent::a3;
      94             :     using Parent::m0;
      95             :     using Parent::m1;
      96             :     using Parent::m2;
      97             :     using Parent::cut_frequency;
      98             :     using Parent::Q;
      99             :     using Parent::input_sampling_rate;
     100             : 
     101             :     explicit SecondOrderSVFLowPassCoefficients(gsl::index nb_channels);
     102             : 
     103             :   protected:
     104             :     void setup() override;
     105             :   };
     106             : 
     107             :   /// Coefficients for a second order SVF band-pass filter
     108             :   template<typename DataType_>
     109             :   class SecondOrderSVFBandPassCoefficients : public SecondOrderSVFBaseCoefficients<DataType_>
     110             :   {
     111             :   public:
     112             :     using Parent = SecondOrderSVFBaseCoefficients<DataType_>;
     113             :     using typename Parent::DataType;
     114             :     using typename Parent::CoeffDataType;
     115             :     using Parent::setup;
     116             :     using Parent::a1;
     117             :     using Parent::a2;
     118             :     using Parent::a3;
     119             :     using Parent::m0;
     120             :     using Parent::m1;
     121             :     using Parent::m2;
     122             :     using Parent::cut_frequency;
     123             :     using Parent::Q;
     124             :     using Parent::input_sampling_rate;
     125             : 
     126             :     explicit SecondOrderSVFBandPassCoefficients(gsl::index nb_channels);
     127             : 
     128             :   protected:
     129             :     void setup() override;
     130             :   };
     131             : 
     132             :   /// Coefficients for a second order SVF high-pass filter
     133             :   template<typename DataType_>
     134             :   class SecondOrderSVFHighPassCoefficients : public SecondOrderSVFBaseCoefficients<DataType_>
     135             :   {
     136             :   public:
     137             :     using Parent = SecondOrderSVFBaseCoefficients<DataType_>;
     138             :     using typename Parent::DataType;
     139             :     using typename Parent::CoeffDataType;
     140             :     using Parent::setup;
     141             :     using Parent::a1;
     142             :     using Parent::a2;
     143             :     using Parent::a3;
     144             :     using Parent::m0;
     145             :     using Parent::m1;
     146             :     using Parent::m2;
     147             :     using Parent::cut_frequency;
     148             :     using Parent::Q;
     149             :     using Parent::input_sampling_rate;
     150             : 
     151             :     explicit SecondOrderSVFHighPassCoefficients(gsl::index nb_channels);
     152             : 
     153             :   protected:
     154             :     void setup() override;
     155             :   };
     156             : 
     157             :   /// Coefficients for a second order SVF notch filter
     158             :   template<typename DataType_>
     159             :   class SecondOrderSVFNotchCoefficients : public SecondOrderSVFBaseCoefficients<DataType_>
     160             :   {
     161             :   public:
     162             :     using Parent = SecondOrderSVFBaseCoefficients<DataType_>;
     163             :     using typename Parent::DataType;
     164             :     using typename Parent::CoeffDataType;
     165             :     using Parent::setup;
     166             :     using Parent::a1;
     167             :     using Parent::a2;
     168             :     using Parent::a3;
     169             :     using Parent::m0;
     170             :     using Parent::m1;
     171             :     using Parent::m2;
     172             :     using Parent::cut_frequency;
     173             :     using Parent::Q;
     174             :     using Parent::input_sampling_rate;
     175             : 
     176             :     explicit SecondOrderSVFNotchCoefficients(gsl::index nb_channels);
     177             : 
     178             :   protected:
     179             :     void setup() override;
     180             :   };
     181             : 
     182             :   /// Coefficients for a second order SVF peak filter
     183             :   template<typename DataType_>
     184             :   class SecondOrderSVFPeakCoefficients : public SecondOrderSVFBaseCoefficients<DataType_>
     185             :   {
     186             :   public:
     187             :     using Parent = SecondOrderSVFBaseCoefficients<DataType_>;
     188             :     using typename Parent::DataType;
     189             :     using typename Parent::CoeffDataType;
     190             :     using Parent::setup;
     191             :     using Parent::a1;
     192             :     using Parent::a2;
     193             :     using Parent::a3;
     194             :     using Parent::m0;
     195             :     using Parent::m1;
     196             :     using Parent::m2;
     197             :     using Parent::cut_frequency;
     198             :     using Parent::Q;
     199             :     using Parent::input_sampling_rate;
     200             : 
     201             :     explicit SecondOrderSVFPeakCoefficients(gsl::index nb_channels);
     202             : 
     203             :   protected:
     204             :     void setup() override;
     205             :   };
     206             : 
     207             :   /// Coefficients for a second order SVF bell filter
     208             :   template<typename DataType_>
     209             :   class SecondOrderSVFBellCoefficients : public SecondOrderSVFBaseCoefficients<DataType_>
     210             :   {
     211             :   public:
     212             :     using Parent = SecondOrderSVFBaseCoefficients<DataType_>;
     213             :     using typename Parent::DataType;
     214             :     using typename Parent::CoeffDataType;
     215             :     using Parent::setup;
     216             :     using Parent::a1;
     217             :     using Parent::a2;
     218             :     using Parent::a3;
     219             :     using Parent::m0;
     220             :     using Parent::m1;
     221             :     using Parent::m2;
     222             :     using Parent::cut_frequency;
     223             :     using Parent::Q;
     224             :     using Parent::input_sampling_rate;
     225             : 
     226             :     explicit SecondOrderSVFBellCoefficients(gsl::index nb_channels);
     227             : 
     228             :     /// Sets the gain of the bell
     229             :     void set_gain(CoeffDataType gain);
     230             :     /// Returns the gain for the bell
     231             :     CoeffDataType get_gain() const;
     232             :   protected:
     233             :     void setup() override;
     234             : 
     235             :     CoeffDataType gain{1};
     236             :   };
     237             : 
     238             :   /// Coefficients for a second order SVF low-pass shelving filter
     239             :   template<typename DataType_>
     240             :   class SecondOrderSVFLowShelfCoefficients : public SecondOrderSVFBaseCoefficients<DataType_>
     241             :   {
     242             :   public:
     243             :     using Parent = SecondOrderSVFBaseCoefficients<DataType_>;
     244             :     using typename Parent::DataType;
     245             :     using typename Parent::CoeffDataType;
     246             :     using Parent::setup;
     247             :     using Parent::a1;
     248             :     using Parent::a2;
     249             :     using Parent::a3;
     250             :     using Parent::m0;
     251             :     using Parent::m1;
     252             :     using Parent::m2;
     253             :     using Parent::cut_frequency;
     254             :     using Parent::Q;
     255             :     using Parent::input_sampling_rate;
     256             : 
     257             :     explicit SecondOrderSVFLowShelfCoefficients(gsl::index nb_channels);
     258             : 
     259             :     /// Sets the gain of the shelf
     260             :     void set_gain(CoeffDataType gain);
     261             :     /// Returns the gain for the shelf
     262             :     CoeffDataType get_gain() const;
     263             :   protected:
     264             :     void setup() override;
     265             : 
     266             :     CoeffDataType gain{1};
     267             :   };
     268             : 
     269             :   /// Coefficients for a second order SVF high-pass shelving filter
     270             :   template<typename DataType_>
     271             :   class SecondOrderSVFHighShelfCoefficients : public SecondOrderSVFBaseCoefficients<DataType_>
     272             :   {
     273             :   public:
     274             :     using Parent = SecondOrderSVFBaseCoefficients<DataType_>;
     275             :     using typename Parent::DataType;
     276             :     using typename Parent::CoeffDataType;
     277             :     using Parent::setup;
     278             :     using Parent::a1;
     279             :     using Parent::a2;
     280             :     using Parent::a3;
     281             :     using Parent::m0;
     282             :     using Parent::m1;
     283             :     using Parent::m2;
     284             :     using Parent::cut_frequency;
     285             :     using Parent::Q;
     286             :     using Parent::input_sampling_rate;
     287             : 
     288             :     explicit SecondOrderSVFHighShelfCoefficients(gsl::index nb_channels);
     289             :     
     290             :     /// Sets the gain of the shelf
     291             :     void set_gain(CoeffDataType gain);
     292             :     /// Returns the gain for the shelf
     293             :     CoeffDataType get_gain() const;
     294             : 
     295             :   protected:
     296             :     void setup() override;
     297             : 
     298             :     CoeffDataType gain{1};
     299             :   };
     300             : }
     301             : 
     302             : #endif