start method

void start(RegionPair region, int channel, int key, int velocity,)

Implementation

void start(RegionPair region, int channel, int key, int velocity) {
  _exclusiveClass = region.exclusiveClass();
  _channel = channel;
  _key = key;
  _velocity = velocity;

  if (velocity > 0) {
    // According to the Polyphone's implementation, the initial attenuation should be reduced to 40%.
    // I'm not sure why, but this indeed improves the loudness variability.
    var sampleAttenuation = 0.4 * region.initialAttenuation();
    var filterAttenuation = 0.5 * region.initialFilterQ();

    var decibels = 2 * SoundFontMath.linearToDecibels(velocity / 127.0) - sampleAttenuation - filterAttenuation;

    _noteGain = SoundFontMath.decibelsToLinear(decibels);
  } else {
    _noteGain = 0;
  }

  _cutoff = region.initialFilterCutoffFrequency();
  _resonance = SoundFontMath.decibelsToLinear(region.initialFilterQ());

  _vibLfoToPitch = 0.01 * region.vibratoLfoToPitch();
  _modLfoToPitch = 0.01 * region.modulationLfoToPitch();
  _modEnvToPitch = 0.01 * region.modulationEnvelopeToPitch();

  _modLfoToCutoff = region.modulationLfoToFilterCutoffFrequency();
  _modEnvToCutoff = region.modulationEnvelopeToFilterCutoffFrequency();

  _dynamicCutoff = _modLfoToCutoff != 0 || _modEnvToCutoff != 0;

  _modLfoToVolume = region.modulationLfoToVolume();
  _dynamicVolume = _modLfoToVolume > 0.05;

  _instrumentPan = region.pan().clamp(-50.0, 50.0);
  _instrumentReverb = 0.01 * region.reverbEffectsSend();
  _instrumentChorus = 0.01 * region.chorusEffectsSend();

  _volEnv.start2(region, key, velocity);
  _modEnv.start2(region, key, velocity);
  _vibLfo.startVibrato2(region, key, velocity);
  _modLfo.startModulation2(region, key, velocity);

  _oscillator.start2(synthesizer.soundFont.waveData, region);

  _filter.clearBuffer();
  _filter.setLowPassFilter(_cutoff, _resonance);

  _smoothedCutoff = _cutoff;

  _voiceState = VoiceState.playing;
  _voiceLength = 0;

  _isSostenutoTarget = false;
}