// .....

void DX7::run (uint32_t sample_count)
{
    const LV2_Atom_Sequence* seq = p<LV2_Atom_Sequence> (p_lv2_events_in);
    float* output = p(p_lv2_audio_out_1)
    uint32_t last_frame = 0, num_this_time = 0;

    for (LV2_Atom_Event* ev = lv2_atom_sequence_begin (&seq->body);
         !lv2_atom_sequence_is_end(&seq->body, seq->atom.size, ev);
         ev = lv2_atom_sequence_next (ev))
    {
       num_this_time = ev->time.frames - last_frame;

       // If it's midi, send it to the engine
       if (ev->body.type == m_midi_type)
          ring_buffer_.Write ((uint8_t*) LV2_ATOM_BODY (&ev->body), ev->body.size);

       // render audio from the last frame until the timestamp of this event
       synth_unit_->GetSamples (num_this_time, outbuf16_);

       // i is the index of the engine's buf, which always starts at 0 (i think)
       // j is the index of the plugin's float output buffer which will be the timestamp
       // of the last processed atom event.
       for (uint32_t i = 0, j = last_frame; i < num_this_time; ++i, ++j)
         output[j] = static_cast<float> (outbuf16_[i]) * scaler;

       last_frame = ev->time.frames;
    }

    // render remaining samples if any left
    if (last_frame < sample_count)
    {
       // do the same thing as above except from last frame until the end of
       // the processing cycles last sample. at this point, all events have
       // already been handled.
       num_this_time = sample_count - last_frame;
       synth_unit_->GetSamples (num_this_time, outbuf16_);
       for (uint32_t i = 0, j = last_frame; i < num_this_time; ++i, ++j)
         output[j] = static_cast<float> (outbuf16_[i]) * scaler;
    }
}

// ....