C++ SigTimer::update方法代码示例

void mainloopalgorithms(void) { 
   // 1. check to see if we are in a new measure and update the
   // metronome accordingly.  If in 4/4, then the metronome will
   // be guarenteed to be between 0 and 3.99999 after the following
   // code is run.  The update will make sure that the metronome remains
   // synced exactly in time with the absolute beat. (Useful for 
   // polyphony, not really necessary in monophonic cases).
   if (metronome.expired() >= meter) {
      metronome.update(meter);
   }

   // 2. Determine the current beat of the meter.
   // We will want to play automated chords on beats one and three.
   beatfraction = metronome.getPeriodCount();
   beat = (int)beatfraction + 1;
   beatfraction -= beat - 1;

   // 3. Process the incoming MIDI note messages (if any), keeping track 
   // of the last note, and whether it is currently on or off.
   while (synth.getNoteCount() > 0) {
      notemessage = synth.extractNote();
      if (notemessage.getP2() != 0) {
         note = notemessage.getP1();
         notestates[note] = 1;
      } else {
         notestates[notemessage.getP1()] = 0;
      }
   }

   // 4. Determine the position in time in the current beat.
   // There are two beat-parts which are called states:
   //    state == 0: we are at the start of the beat and may need to
   //                choose a new chord.
   //    state == 1: we are past the maximum wait time for a chord decision
   // Also, check to see if the state has changed from 0 to 1 or 1 to 0.
   oldstate = state;
   state = beatfraction < maxwait ? 0 : 1;
   stateChange = (state != oldstate);

   // 5. Check to see if a chord needs to be played.
   if (stateChange && state == 0) {
      playMetronome(beat);
      if (chordBeat(beat, meter)) {
         notescan = 1;
      } else {
         playChord(currentnote, OFF);
      }
   }

   if (notescan && notestates[note]) {   // if note played in beat window
      currentnote = note;
      playChord(currentnote, ON);
      notescan = 0;
   } else if (notescan && state == 1) {  // if too late for a new note
      playChord(currentnote, ON);
      notescan = 0;
   }
}

void mainloopalgorithms(void) { 
   if (comparestate && notetimer.expired()) {
      if (notetimer.expired() > 2) {
         notetimer.reset();
      } else {
         notetimer.update();
      }

      notestate = !notestate;
      if (notestate == 1 || notestate == -1) {
         synth.play(0, note, 64);
         data = 0x90; sentout.insert(data);
         data = note; sentout.insert(data);
         data = 64;   sentout.insert(data);
      } else {
         synth.play(0, note, 0);
         data = 0x90; sentout.insert(data);
         data = note; sentout.insert(data);
         data = 0;    sentout.insert(data);
         note += step * direction;
         if (note > highestnote) {
            note = lowestnote;
         }
         if (note < lowestnote) {
            note = highestnote;
         }
      }
   }

   if (midiinput.getCount() > 0) {
      message = midiinput.extract();
      receivedin.insert(message.p0());
      receivedin.insert(message.p1());
      receivedin.insert(message.p2());

      // check that the messages are identical
      if (receivedin.getCount() < 3) {
         cout << "Error: not enough received data" << endl;
      } else {
         checkin[0] = receivedin.extract();
         checkin[1] = receivedin.extract();
         checkin[2] = receivedin.extract();
      }

      if (sentout.getCount() < 3) {
         cout << "Error: not enough sent data" << endl;
      } else {
         checkout[0] = sentout.extract();
         checkout[1] = sentout.extract();
         checkout[2] = sentout.extract();
      }

      if ((checkout[0] != checkin[0]) || (checkout[1] != checkin[1]) ||
          (checkout[2] != checkin[2])) {
         synth.rawsend(0xaa, 0x7f, 0x00);
         cout << "Error " 
              << "output was = (" << hex << (int)checkout[0] << ") "
              << dec << (int)checkout[1] << " "
              << dec << (int)checkout[2] << "\tbut input is = ("
              << hex << (int)checkin[0] << ") "
              << dec << (int)checkin[1] << " "
              << dec << (int)checkin[2] << " "
              << endl;

         // assume that a note message was missed.
         if (sentout.getCount() < 3) {
            cout << "Error: not enough sent data during error" << endl;
         } else {
            checkout[0] = sentout.extract();
            checkout[1] = sentout.extract();
            checkout[2] = sentout.extract();
         }

         stop();  
         cout << "Press space to restart testing, "
                 "or press 'S' to silence synth" << endl;
      }

   }
 
}