offlinerender.cpp

int bufsize = m_aman.getCurrentAudioDevice()->getCurrentBufferSizeSamples();
  // need to stop the realtime playback so we don't get conflicts while offline rendering
  m_aman.removeAudioCallback(&m_aeng);
  m_aeng.seekToSeconds(0.0);

  juce::WavAudioFormat wavformat;
  juce::File f = juce::File::getSpecialLocation(juce::File::userDocumentsDirectory);
  auto outfile = f.getNonexistentChildFile("upic_renders/upic_out",".wav");
  auto ostream = outfile.createOutputStream();
  auto writer = wavformat.createWriterFor(ostream.release(),m_aeng.m_sr,2,32,{},0);
  bool was_playing = m_aeng.getPlayState();
  if (writer)
  {
      if (m_aeng.getPlayState()==false)
          m_aeng.setPlayState(true);
      juce::AudioBuffer<float> procbuf(2,bufsize);
      procbuf.clear();
      double outlen = m_aeng.getScoreLength();
      bool m_was_looping = m_aeng.m_transport_loop;
      m_aeng.m_transport_loop = false;
      while (m_aeng.m_phase<m_aeng.getScoreLength()*m_aeng.m_sr)
      {
          m_aeng.audioDeviceIOCallbackWithContext(nullptr,0,procbuf.getArrayOfWritePointers(),2,bufsize,{});
          writer->writeFromAudioSampleBuffer(procbuf,0,bufsize);
      }
      m_aeng.m_transport_loop = m_was_looping;
      m_aeng.setPlayState(false);
      delete writer;
  }