PerTrackEffect.h

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/**********************************************************************
 
  Audacity: A Digital Audio Editor
 
  PerTrackEffect.h
 
  Dominic Mazzoni
  Vaughan Johnson
 
  Paul Licameli split from Effect.h
 
**********************************************************************/
 
#ifndef __AUDACITY_PER_TRACK_EFFECT__
#define __AUDACITY_PER_TRACK_EFFECT__
 
#include "AudioGraphSink.h" // to inherit
#include "AudioGraphSource.h" // to inherit
#include "Effect.h" // to inherit
#include "MemoryX.h"
#include "SampleCount.h"
#include <functional>
#include <memory>
 
class EffectOutputTracks;
class SampleTrack;
 
 
class EFFECTS_API PerTrackEffect
   : public Effect
{
public:
   ~PerTrackEffect() override;
 
   class EFFECTS_API Instance : public virtual EffectInstanceEx {
   public:
      explicit Instance(const PerTrackEffect &processor)
         : mProcessor{ processor }
      {}
      ~Instance() override;
   
      bool Process(EffectSettings &settings) final;
 
      bool ProcessInitialize(EffectSettings &settings,
         double sampleRate, ChannelNames chanMap) override;
 
      bool ProcessFinalize() noexcept override;
   protected:
      const PerTrackEffect &mProcessor;
   };
 
protected:
   // These were overridables but the generality wasn't used yet
   /* virtual */ bool DoPass1() const;
   /* virtual */ bool DoPass2() const;
 
   // non-virtual
   bool Process(EffectInstance &instance, EffectSettings &settings) const;
 
   sampleCount    mSampleCnt{};
 
   // Pre-compute the output track list
   std::shared_ptr<EffectOutputTracks> MakeOutputTracks();
 
   // Clean up unnecessary output track list
   void DestroyOutputTracks() const;
 
private:
   using Buffers = AudioGraph::Buffers;
 
   bool ProcessPass(TrackList &outputs,
      Instance &instance, EffectSettings &settings);
   using Factory = std::function<std::shared_ptr<EffectInstance>()>;
   static bool ProcessTrack(int channel,
      const Factory &factory, EffectSettings &settings,
      AudioGraph::Source &source, AudioGraph::Sink &sink,
      std::optional<sampleCount> genLength,
      double sampleRate, const SampleTrack &leader,
      Buffers &inBuffers, Buffers &outBuffers);
 
   // TODO: put this in struct EffectContext? (Which doesn't exist yet)
   mutable std::shared_ptr<EffectOutputTracks> mpOutputTracks;
};
#endif