Method PlayTone

endless-tunnel/app/src/main/cpp/sfxman.cpp:221–292

}

void SfxMan::PlayTone(const char* tone) {
  if (!mInitOk) {
    LOGW("SfxMan: not playing sound because initialization failed.");
    return;
  }
  if (_bufferActive) {
    // can't play -- the buffer is in use
    LOGW("SfxMan: can't play tone; buffer is active.");
    return;
  }

  // synth the tone
  int total_samples = 0;
  int num_samples;
  int frequency = 100;
  int duration = 50;
  int volume_int;
  float amplitude = DEFAULT_VOLUME;

  while (*tone) {
    switch (*tone) {
      case 'f':
        // set frequency
        tone = _parseInt(tone + 1, &frequency);
        break;
      case 'd':
        // set duration
        tone = _parseInt(tone + 1, &duration);
        break;
      case 'a':
        // set amplitude.
        tone = _parseInt(tone + 1, &volume_int);
        amplitude = volume_int / 100.0f;
        amplitude = amplitude < 0.0f   ? 0.0f
                    : amplitude > 1.0f ? 1.0f
                                       : amplitude;
        break;
      case '.':
        // synth
        num_samples = duration * SAMPLES_PER_SEC / 1000;
        if (num_samples > (BUF_SAMPLES_MAX - total_samples - 1)) {
          num_samples = BUF_SAMPLES_MAX - total_samples - 1;
        }
        num_samples = _synth(frequency, amplitude, _sample_buf + total_samples,
                             num_samples);
        total_samples += num_samples;
        tone++;
        break;
      default:
        // ignore and advance to next character
        tone++;
    }
  }

  SLresult result;
  int total_size = total_samples * sizeof(short);
  if (total_size <= 0) {
    LOGW("Tone is empty. Not playing.");