gearmulator

Emulation of classic VA synths of the late 90s/2000s that are based on Motorola 56300 family DSPs
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MemFunCallbackStream.hxx (3315B)

      1 #ifndef INCLUDED_PORTAUDIO_MEMFUNCALLBACKSTREAM_HXX
      2 #define INCLUDED_PORTAUDIO_MEMFUNCALLBACKSTREAM_HXX
      3 
      4 // ---------------------------------------------------------------------------------------
      5 
      6 #include "portaudio.h"
      7 
      8 #include "portaudiocpp/CallbackStream.hxx"
      9 #include "portaudiocpp/CallbackInterface.hxx"
     10 #include "portaudiocpp/StreamParameters.hxx"
     11 #include "portaudiocpp/Exception.hxx"
     12 #include "portaudiocpp/InterfaceCallbackStream.hxx"
     13 
     14 // ---------------------------------------------------------------------------------------
     15 
     16 namespace portaudio
     17 {
     18 
     19 
     20 	//////
     21 	/// @brief Callback stream using a class's member function as a callback. Template argument T is the type of the 
     22 	/// class of which a member function is going to be used.
     23 	///
     24 	/// Example usage:
     25 	/// @verbatim MemFunCallback<MyClass> stream = MemFunCallbackStream(parameters, *this, &MyClass::myCallbackFunction); @endverbatim
     26 	//////
     27 	template<typename T>
     28 	class MemFunCallbackStream : public CallbackStream
     29 	{
     30 	public:
     31 		typedef int (T::*CallbackFunPtr)(const void *, void *, unsigned long, const PaStreamCallbackTimeInfo *, 
     32 			PaStreamCallbackFlags);
     33 
     34 		// -------------------------------------------------------------------------------
     35 
     36 		MemFunCallbackStream()
     37 		{
     38 		}
     39 
     40 		MemFunCallbackStream(const StreamParameters &parameters, T &instance, CallbackFunPtr memFun) : adapter_(instance, memFun)
     41 		{
     42 			open(parameters);
     43 		}
     44 
     45 		~MemFunCallbackStream()
     46 		{
     47 			close();
     48 		}
     49 
     50 		void open(const StreamParameters &parameters, T &instance, CallbackFunPtr memFun)
     51 		{
     52 			// XXX:	need to check if already open?
     53 
     54 			adapter_.init(instance, memFun);
     55 			open(parameters);
     56 		}
     57 
     58 	private:
     59 		MemFunCallbackStream(const MemFunCallbackStream &); // non-copyable
     60 		MemFunCallbackStream &operator=(const MemFunCallbackStream &); // non-copyable
     61 
     62 		//////
     63 		/// @brief Inner class which adapts a member function callback to a CallbackInterface compliant 
     64 		/// class (so it can be adapted using the paCallbackAdapter function).
     65 		//////
     66 		class MemFunToCallbackInterfaceAdapter : public CallbackInterface
     67 		{
     68 		public:
     69 			MemFunToCallbackInterfaceAdapter() {}
     70 			MemFunToCallbackInterfaceAdapter(T &instance, CallbackFunPtr memFun) : instance_(&instance), memFun_(memFun) {}
     71 
     72 			void init(T &instance, CallbackFunPtr memFun)
     73 			{
     74 				instance_ = &instance;
     75 				memFun_ = memFun;
     76 			}
     77 
     78 			int paCallbackFun(const void *inputBuffer, void *outputBuffer, unsigned long numFrames, 
     79 				const PaStreamCallbackTimeInfo *timeInfo, PaStreamCallbackFlags statusFlags)
     80 			{
     81 				return (instance_->*memFun_)(inputBuffer, outputBuffer, numFrames, timeInfo, statusFlags);
     82 			}
     83 
     84 		private:
     85 			T *instance_;
     86 			CallbackFunPtr memFun_;
     87 		};
     88 
     89 		MemFunToCallbackInterfaceAdapter adapter_;
     90 
     91 		void open(const StreamParameters &parameters)
     92 		{
     93 			PaError err = Pa_OpenStream(&stream_, parameters.inputParameters().paStreamParameters(), parameters.outputParameters().paStreamParameters(), 
     94 				parameters.sampleRate(), parameters.framesPerBuffer(), parameters.flags(), &impl::callbackInterfaceToPaCallbackAdapter, 
     95 				static_cast<void *>(&adapter_));
     96 
     97 			if (err != paNoError)
     98 				throw PaException(err);
     99 		}
    100 	};
    101 
    102 
    103 } // portaudio
    104 
    105 // ---------------------------------------------------------------------------------------
    106 
    107 #endif // INCLUDED_PORTAUDIO_MEMFUNCALLBACKSTREAM_HXX