EchoBase.h

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/**********************************************************************
 
  Audacity: A Digital Audio Editor
 
  EchoBase.h
 
  Dominic Mazzoni
  Vaughan Johnson (dialog)
 
**********************************************************************/
#pragma once
 
#include "MemoryX.h"
#include "PerTrackEffect.h"
#include "SettingsVisitor.h"
#include <cfloat>
 
using Floats = ArrayOf<float>;
 
struct EchoSettings
{
   static constexpr double delayDefault = 1.0;
   static constexpr double decayDefault = 0.5;
 
   double delay { delayDefault };
   double decay { decayDefault };
};
 
class BUILTIN_EFFECTS_API EchoBase :
    public EffectWithSettings<EchoSettings, PerTrackEffect>
{
public:
   static const ComponentInterfaceSymbol Symbol;
 
   EchoBase();
   virtual ~EchoBase();
 
   // ComponentInterface implementation
 
   ComponentInterfaceSymbol GetSymbol() const override;
   TranslatableString GetDescription() const override;
   ManualPageID ManualPage() const override;
 
   // EffectDefinitionInterface implementation
 
   EffectType GetType() const override;
 
   struct BUILTIN_EFFECTS_API Instance :
       public PerTrackEffect::Instance,
       public EffectInstanceWithBlockSize
   {
      Instance(const PerTrackEffect& effect)
          : PerTrackEffect::Instance { effect }
      {
      }
 
      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;
 
      bool ProcessFinalize() noexcept override;
 
      unsigned GetAudioOutCount() const override
      {
         return 1;
      }
 
      unsigned GetAudioInCount() const override
      {
         return 1;
      }
 
      Floats history;
      size_t histPos;
      size_t histLen;
   };
 
protected:
   // EchoBase implementation
   const EffectParameterMethods& Parameters() const override;
 
#if 0
   // TODO simplify like this in C++20
   using ParametersType = CapturedParameters<EchoBase,
        EffectParameter{
         &EchoBase::delay, L"Delay",   1.0f, 0.001f,  FLT_MAX, 1.0f }
      , EffectParameter{
         &EchoBase::decay, L"Decay",   0.5f, 0.0f,    FLT_MAX, 1.0f }
   >;
#else
 
   static constexpr EffectParameter Delay { &EchoSettings::delay,
                                            L"Delay",
                                            EchoSettings::delayDefault,
                                            0.001f,
                                            FLT_MAX,
                                            1.0f };
   static constexpr EffectParameter Decay { &EchoSettings::decay,
                                            L"Decay",
                                            EchoSettings::decayDefault,
                                            0.0f,
                                            FLT_MAX,
                                            1.0f };
 
#endif
};