AudioUnitWrapper.h

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/*!********************************************************************
 
  Audacity: A Digital Audio Editor
 
  @file AudioUnitWrapper.h
 
  Dominic Mazzoni
  Leland Lucius
 
  Paul Licameli split from AudioUnitEffect.h
 
**********************************************************************/
#ifndef AUDACITY_AUDIOUNIT_WRAPPER_H
#define AUDACITY_AUDIOUNIT_WRAPPER_H
 
#if USE_AUDIO_UNITS
 
#include <optional>
#include <map>
#include <set>
#include <unordered_map>
#include <wx/string.h>
 
#include "AudioUnitUtils.h"
#include "Identifier.h"
 
class wxCFStringRef;
class wxMemoryBuffer;
class EffectDefinitionInterface;
class EffectSettings;
class TranslatableString;
class AudioUnitWrapper;
 
struct AudioUnitEffectSettings {
 
   using StringSet = std::set<wxString>;
   const std::shared_ptr<StringSet> mSharedNames{
      std::make_shared<StringSet>() };
 
   std::optional<SInt32> mPresetNumber;
   
   using Pair = std::pair<const wxString &, AudioUnitParameterValue>;
   using Map = std::map<AudioUnitParameterID, std::optional<Pair>>;
   Map values;
 
   AudioUnitEffectSettings() = default;
   AudioUnitEffectSettings(Map map) : values{ move(map) } {}
   
   const wxString &Intern(const wxString &name) {
      // std::set::insert guarantees this iterator is not at the end
      auto [iter, _] = mSharedNames->insert(name);
      // so dereference it merrily
      return *iter;
   }
 
   void ResetValues()
   {
      for (auto &[_, value] : values)
         value.reset();
   }
};
 
 
struct AudioUnitWrapper
{
   using Parameters = PackedArray::Ptr<const AudioUnitParameterID>;
 
   static AudioUnitEffectSettings &GetSettings(EffectSettings &settings);
   static const AudioUnitEffectSettings &GetSettings(
      const EffectSettings &settings);
 
   AudioUnitWrapper(AudioComponent component, Parameters *pParameters)
      : mComponent{ component }
      , mParameters{ pParameters ? *pParameters : mOwnParameters }
   {
   }
 
   // Supply most often used values as defaults for scope and element
   template<typename T>
   OSStatus GetFixedSizeProperty(AudioUnitPropertyID inID, T &property,
      AudioUnitScope inScope = kAudioUnitScope_Global,
      AudioUnitElement inElement = 0) const
   {
      // Supply mUnit.get() to the non-member function
      return AudioUnitUtils::GetFixedSizeProperty(mUnit.get(),
         inID, property, inScope, inElement);
   }
 
   // Supply most often used values as defaults for scope and element
   template<typename T>
   OSStatus GetVariableSizeProperty(AudioUnitPropertyID inID,
      PackedArray::Ptr<T> &pObject,
      AudioUnitScope inScope = kAudioUnitScope_Global,
      AudioUnitElement inElement = 0) const
   {
      return AudioUnitUtils::GetVariableSizeProperty(mUnit.get(),
         inID, pObject, inScope, inElement);
   }
 
   // Supply most often used values as defaults for scope and element
   template<typename T>
   OSStatus SetProperty(AudioUnitPropertyID inID, const T &property,
      AudioUnitScope inScope = kAudioUnitScope_Global,
      AudioUnitElement inElement = 0) const
   {
      // Supply mUnit.get() to the non-member function
      return AudioUnitUtils::SetProperty(mUnit.get(),
         inID, property, inScope, inElement);
   }
 
   class ParameterInfo;
   using ParameterVisitor =
      std::function< bool(const ParameterInfo &pi, AudioUnitParameterID ID) >;
   void ForEachParameter(ParameterVisitor visitor) const;
 
   bool LoadPreset(const EffectDefinitionInterface &effect,
      const RegistryPath & group, EffectSettings &settings) const;
   bool LoadFactoryPreset(const EffectDefinitionInterface &effect,
      int id, EffectSettings *pSettings) const;
 
 
   std::pair<CF_ptr<CFDataRef>, TranslatableString>
   MakeBlob(const EffectDefinitionInterface &effect,
      const AudioUnitEffectSettings &settings,
      const wxCFStringRef &cfname, bool binary) const;
 
 
   TranslatableString InterpretBlob(AudioUnitEffectSettings &settings,
      const wxString &group, const wxMemoryBuffer &buf) const;
 
   bool FetchSettings(AudioUnitEffectSettings &settings,
      bool fetchValues, bool fetchPreset = false) const;
   bool StoreSettings(const EffectDefinitionInterface &effect,
      const AudioUnitEffectSettings &settings) const;
 
   static bool MoveSettingsContents(
      AudioUnitEffectSettings &&src, AudioUnitEffectSettings &dst, bool merge);
 
   bool CreateAudioUnit();
 
   AudioUnit GetAudioUnit() const { return mUnit.get(); }
   AudioComponent GetComponent() const { return mComponent; }
   const Parameters &GetParameters() const
   { return mParameters; }
 
   // @param identifier only for logging messages
   bool SetRateAndChannels(double sampleRate, const wxString &identifier);
 
protected:
   const AudioComponent mComponent;
   AudioUnitCleanup<AudioUnit, AudioComponentInstanceDispose> mUnit;
 
   Parameters mOwnParameters;
   Parameters &mParameters;
 
   // Reassinged in GetRateAndChannels()
   unsigned mAudioIns{ 2 };
   unsigned mAudioOuts{ 2 };
};
 
class AudioUnitWrapper::ParameterInfo final
{
public:
   ParameterInfo(AudioUnit mUnit, AudioUnitParameterID parmID);
   static std::optional<AudioUnitParameterID> ParseKey(const wxString &key);
 
   std::optional<wxString> mName;
   AudioUnitUtils::ParameterInfo mInfo{};
 
private:
   // constants
   static constexpr char idBeg = wxT('<');
   static constexpr char idSep = wxT(',');
   static constexpr char idEnd = wxT('>');
};
 
#endif
 
#endif