LV2Wrapper.h

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/**********************************************************************
 
  Audacity: A Digital Audio Editor
 
  @file LV2Wrapper.h
  @brief manager for a handle to an lv2 plug-in instance and request and
  response queues for inter-thread work scheduling
 
  Paul Licameli split from LV2Effect.h
 
  Audacity(R) is copyright (c) 1999-2013 Audacity Team.
  License: GPL v2 or later.  See License.txt.
 
*********************************************************************/
 
#ifndef __AUDACITY_LV2_WRAPPER__
#define __AUDACITY_LV2_WRAPPER__
 
#if USE_LV2
 
#include "LV2Utils.h"
#include "LV2InstanceFeaturesList.h"
 
#include "lilv/lilv.h"
#include "lv2/core/attributes.h"
#include "lv2/options/options.h"
#include "lv2/state/state.h"
#include "lv2/worker/worker.h"
 
#include <thread>
#include <wx/msgqueue.h>
 
struct EffectOutputs;
struct LV2EffectSettings;
class LV2Ports;
class LV2PortStates;
using LilvInstancePtr = Lilv_ptr<LilvInstance, lilv_instance_free>;
 
// We use deprecated LV2 interfaces to remain compatible with older
// plug-ins, so disable warnings
LV2_DISABLE_DEPRECATION_WARNINGS
 
class LV2_API LV2Wrapper final
{
   struct CreateToken{};
public:
   struct LV2Work {
      uint32_t size{};
      const void *data{};
   };
 
public:
   static std::unique_ptr<LV2Wrapper> Create(
      LV2InstanceFeaturesList &baseFeatures,
      const LV2Ports &ports, LV2PortStates &portStates,
      const LV2EffectSettings &settings, float sampleRate,
      EffectOutputs *pOutputs);
 
   LV2Wrapper(CreateToken&&,
      LV2InstanceFeaturesList &baseFeatures,
      const LilvPlugin &plugin, float sampleRate);
 
   ~LV2Wrapper();
 
   void ConnectControlPorts(const LV2Ports &ports,
      const LV2EffectSettings &settings, EffectOutputs *pOutputs);
   void ConnectPorts(const LV2Ports &ports,
      LV2PortStates &portStates, const LV2EffectSettings &settings,
      EffectOutputs *pOutputs);
   void Activate();
   void Deactivate();
   LilvInstance &GetInstance() const;
   LV2_Handle GetHandle() const;
   float GetLatency() const;
   void SetFreeWheeling(bool enable);
   void SendBlockSize();
   void ConsumeResponses();
   static LV2_Worker_Status schedule_work(LV2_Worker_Schedule_Handle handle,
                                          uint32_t size,
                                          const void *data);
   LV2_Worker_Status ScheduleWork(uint32_t size, const void *data);
   static LV2_Worker_Status respond(LV2_Worker_Respond_Handle handle,
                                    uint32_t size,
                                    const void *data);
   LV2_Worker_Status Respond(uint32_t size, const void *data);
 
   LV2WrapperFeaturesList &GetFeatures() { return mFeaturesList; }
   const LV2WrapperFeaturesList &GetFeatures() const { return mFeaturesList; }
 
private:
   void ThreadFunction();
 
   // Another object with an explicit virtual function table
   LV2_Worker_Schedule mWorkerSchedule{ this, LV2Wrapper::schedule_work };
 
   LV2WrapperFeaturesList mFeaturesList;
 
   const LilvInstancePtr mInstance;
   const LV2_Handle mHandle;
 
   // Pointers to extension interfaces that the foreign plug-in instance
   // may expose:
   // Options extension
   const LV2_Options_Interface *const mOptionsInterface;
   // State extension
   const LV2_State_Interface *const mStateInterface;
   // Worker extension
   const LV2_Worker_Interface *const mWorkerInterface;
 
   std::thread mThread;
   wxMessageQueue<LV2Work> mRequests;
   wxMessageQueue<LV2Work> mResponses;
   float mLatency{ 0.0 };
 
   bool mFreeWheeling{ false };
 
   bool mStopWorker{ false };
   bool mActivated{ false };
};
 
#endif
#endif