gearmulator

sine.cxx (3801B)

---

 // ---------------------------------------------------------------------------------------
 
 #include <iostream>
 #include <cmath>
 #include <cassert>
 #include <cstddef>
 #include "portaudiocpp/PortAudioCpp.hxx"
 
 // ---------------------------------------------------------------------------------------
 
 // Some constants:
 const int NUM_SECONDS = 5;
 const double SAMPLE_RATE = 44100.0;
 const int FRAMES_PER_BUFFER = 64;
 const int TABLE_SIZE = 200;
 
 // ---------------------------------------------------------------------------------------
 
 // SineGenerator class:
 class SineGenerator
 {
 public:
 	SineGenerator(int tableSize) : tableSize_(tableSize), leftPhase_(0), rightPhase_(0)
 	{
 		const double PI = 3.14159265;
 		table_ = new float[tableSize];
 		for (int i = 0; i < tableSize; ++i)
 		{
 			table_[i] = 0.125f * (float)sin(((double)i/(double)tableSize)*PI*2.);
 		}
 	}
 
 	~SineGenerator()
 	{
 		delete[] table_;
 	}
 
 	int generate(const void *inputBuffer, void *outputBuffer, unsigned long framesPerBuffer, 
 		const PaStreamCallbackTimeInfo *timeInfo, PaStreamCallbackFlags statusFlags)
 	{
 		assert(outputBuffer != NULL);
 
 		float **out = static_cast<float **>(outputBuffer);
 
 		for (unsigned int i = 0; i < framesPerBuffer; ++i)
 		{
 			out[0][i] = table_[leftPhase_];
 			out[1][i] = table_[rightPhase_];
 
 			leftPhase_ += 1;
 			if (leftPhase_ >= tableSize_)
 				leftPhase_ -= tableSize_;
 
 			rightPhase_ += 3;
 			if (rightPhase_ >= tableSize_)
 				rightPhase_ -= tableSize_;
 		}
 
 		return paContinue;
 	}
 
 private:
 	float *table_;
 	int tableSize_;
 	int leftPhase_;
 	int rightPhase_;
 };
 
 // ---------------------------------------------------------------------------------------
 
 // main:
 int main(int, char *[]);
 int main(int, char *[])
 {
 	try
 	{
 		// Create a SineGenerator object:
 		SineGenerator sineGenerator(TABLE_SIZE);
 
 		std::cout << "Setting up PortAudio..." << std::endl;
 
 		// Set up the System:
 		portaudio::AutoSystem autoSys;
 		portaudio::System &sys = portaudio::System::instance();
 
 		// Set up the parameters required to open a (Callback)Stream:
 		portaudio::DirectionSpecificStreamParameters outParams(sys.defaultOutputDevice(), 2, portaudio::FLOAT32, false, sys.defaultOutputDevice().defaultLowOutputLatency(), NULL);
 		portaudio::StreamParameters params(portaudio::DirectionSpecificStreamParameters::null(), outParams, SAMPLE_RATE, FRAMES_PER_BUFFER, paClipOff);
 
 		std::cout << "Opening stereo output stream..." << std::endl;
 
 		// Create (and open) a new Stream, using the SineGenerator::generate function as a callback:
 		portaudio::MemFunCallbackStream<SineGenerator> stream(params, sineGenerator, &SineGenerator::generate);
 
 		std::cout << "Starting playback for " << NUM_SECONDS << " seconds." << std::endl;
 
 		// Start the Stream (audio playback starts):
 		stream.start();
 
 		// Wait for 5 seconds:
 		sys.sleep(NUM_SECONDS * 1000);
 
 		std::cout << "Closing stream..." <<std::endl;
 
 		// Stop the Stream (not strictly needed as termintating the System will also stop all open Streams):
 		stream.stop();
 
 		// Close the Stream (not strictly needed as terminating the System will also close all open Streams):
 		stream.close();
 
 		// Terminate the System (not strictly needed as the AutoSystem will also take care of this when it 
 		// goes out of scope):
 		sys.terminate();
 
 		std::cout << "Test finished." << std::endl;
 	}
 	catch (const portaudio::PaException &e)
 	{
 		std::cout << "A PortAudio error occured: " << e.paErrorText() << std::endl;
 	}
 	catch (const portaudio::PaCppException &e)
 	{
 		std::cout << "A PortAudioCpp error occured: " << e.what() << std::endl;
 	}
 	catch (const std::exception &e)
 	{
 		std::cout << "A generic exception occured: " << e.what() << std::endl;
 	}
 	catch (...)
 	{
 		std::cout << "An unknown exception occured." << std::endl;
 	}
 
 	return 0;
 }