ScienFilterBase.h

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/**********************************************************************
 
Audacity: A Digital Audio Editor
 
ScienFilterBase.h
 
Norm C
Mitch Golden
Vaughan Johnson (Preview)
 
***********************************************************************/
#pragma once
 
#include "Biquad.h"
#include "ShuttleAutomation.h"
#include "StatefulPerTrackEffect.h"
#include <cfloat> // for FLT_MAX
 
class BUILTIN_EFFECTS_API ScienFilterBase : public StatefulPerTrackEffect
{
public:
   static inline ScienFilterBase*
   FetchParameters(ScienFilterBase& e, EffectSettings&)
   {
      return &e;
   }
   static const ComponentInterfaceSymbol Symbol;
 
   ScienFilterBase();
   virtual ~ScienFilterBase();
 
   // ComponentInterface implementation
 
   ComponentInterfaceSymbol GetSymbol() const override;
   TranslatableString GetDescription() const override;
   ManualPageID ManualPage() const override;
 
   // EffectDefinitionInterface implementation
 
   EffectType GetType() const override;
 
   unsigned GetAudioInCount() const override;
   unsigned GetAudioOutCount() const override;
   bool ProcessInitialize(
      EffectSettings& settings, double sampleRate,
      ChannelNames chanMap) override;
   size_t ProcessBlock(
      EffectSettings& settings, const float* const* inBlock,
      float* const* outBlock, size_t blockLen) override;
 
   // Effect implementation
 
   bool Init() override;
 
protected:
   // ScienFilterBase implementation
 
   void CalcFilter();
   float FilterMagnAtFreq(float Freq);
 
   float mCutoff;
   float mRipple;
   float mStopbandRipple;
   int mFilterType;    // Butterworth etc.
   int mFilterSubtype; // lowpass, highpass
   int mOrder;
   int mOrderIndex;
   ArrayOf<Biquad> mpBiquad;
 
   double mdBMax;
   double mdBMin;
   bool mEditingBatchParams;
 
   double mLoFreq;
   double mNyquist;
 
   const EffectParameterMethods& Parameters() const override;
 
   enum kSubTypes
   {
      kLowPass = Biquad::kLowPass,
      kHighPass = Biquad::kHighPass,
      nSubTypes = Biquad::nSubTypes
   };
   static const EnumValueSymbol kSubTypeStrings[nSubTypes];
 
   enum kTypes
   {
      kButterworth,
      kChebyshevTypeI,
      kChebyshevTypeII,
      nTypes
   };
   static const EnumValueSymbol kTypeStrings[nTypes];
 
   static_assert(nSubTypes == WXSIZEOF(kSubTypeStrings), "size mismatch");
 
   static constexpr EnumParameter Type { &ScienFilterBase::mFilterType,
                                         L"FilterType",
                                         kButterworth,
                                         0,
                                         nTypes - 1,
                                         1,
                                         kTypeStrings,
                                         nTypes };
   static constexpr EnumParameter Subtype { &ScienFilterBase::mFilterSubtype,
                                            L"FilterSubtype",
                                            kLowPass,
                                            0,
                                            nSubTypes - 1,
                                            1,
                                            kSubTypeStrings,
                                            nSubTypes };
   static constexpr EffectParameter Order {
      &ScienFilterBase::mOrder, L"Order", 1, 1, 10, 1
   };
   static constexpr EffectParameter Cutoff {
      &ScienFilterBase::mCutoff, L"Cutoff", 1000.0f, 1.0, FLT_MAX, 1
   };
   static constexpr EffectParameter Passband {
      &ScienFilterBase::mRipple, L"PassbandRipple", 1.0f, 0.0, 100.0, 1
   };
   static constexpr EffectParameter Stopband {
      &ScienFilterBase::mStopbandRipple, L"StopbandRipple", 30.0f, 0.0, 100.0, 1
   };
};