stk/projects/examples/bethree.cpp

// bethree.cpp STK tutorial program

#include "BeeThree.h"
#include "RtAudio.h"
using namespace stk;

// The TickData structure holds all the class instances and data that
// are shared by the various processing functions.
struct TickData {
  Instrmnt *instrument;
  StkFloat frequency;
  StkFloat scaler;
  long counter;
  bool done;

  // Default constructor.
  TickData()
    : instrument(0), scaler(1.0), counter(0), done( false ) {}
};

// This tick() function handles sample computation only.  It will be
// called automatically when the system needs a new buffer of audio
// samples.
int tick( void *outputBuffer, void *inputBuffer, unsigned int nBufferFrames,
         double streamTime, RtAudioStreamStatus status, void *userData )
{
  TickData *data = (TickData *) userData;
  StkFloat *samples = (StkFloat *) outputBuffer;

  for ( unsigned int i=0; i<nBufferFrames; i++ ) {
    *samples++ = data->instrument->tick();
    if ( ++data->counter % 2000 == 0 ) {
      data->scaler += 0.025;
      data->instrument->setFrequency( data->frequency * data->scaler );
    }
  }

  if ( data->counter > 80000 )
    data->done = true;

  return 0;
}

int main()
{
  // Set the global sample rate and rawwave path before creating class instances.
  Stk::setSampleRate( 44100.0 );
  Stk::setRawwavePath( "../../rawwaves/" );

  TickData data;
  RtAudio dac;

  // Figure out how many bytes in an StkFloat and setup the RtAudio stream.
  RtAudio::StreamParameters parameters;
  parameters.deviceId = dac.getDefaultOutputDevice();
  parameters.nChannels = 1;
  RtAudioFormat format = ( sizeof(StkFloat) == 8 ) ? RTAUDIO_FLOAT64 : RTAUDIO_FLOAT32;
  unsigned int bufferFrames = RT_BUFFER_SIZE;
  if ( dac.openStream( &parameters, NULL, format, (unsigned int)Stk::sampleRate(), &bufferFrames, &tick, (void *)&data ) ) {
    std::cout << dac.getErrorText() << std::endl;
    goto cleanup;
  }

  try {
    // Define and load the BeeThree instrument
    data.instrument = new BeeThree();
  }
  catch ( StkError & ) {
    goto cleanup;
  }

  data.frequency = 220.0;
  data.instrument->noteOn( data.frequency, 0.5 );

  if ( dac.startStream() ) {
    std::cout << dac.getErrorText() << std::endl;
    goto cleanup;
  }

  // Block waiting until callback signals done.
  while ( !data.done )
    Stk::sleep( 100 );
  
  // Shut down the callback and output stream.
  dac.closeStream();

 cleanup:
  delete data.instrument;

  return 0;
}