p5sound-setVolume-method.js

p5.SoundFile.prototype.setVolume = function (vol, rampTime, tFromNow, volFrom, volTo) {
    if (typeof vol === 'number') {
      var rampTime = rampTime || 0;
      var tFromNow = tFromNow || 0;
      var now = p5sound.audiocontext.currentTime;
      var currentVol = this.output.gain.value;
      this.output.gain.cancelScheduledValues(now + tFromNow);
      // Attack
      if (typeof volFrom === 'number' && volFrom >= 0) {
        this.output.gain.linearRampToValueAtTime(volFrom, now + tFromNow);
      } else {
        this.output.gain.linearRampToValueAtTime(currentVol, now + tFromNow);
      }
      // Decay
      if (typeof volTo === 'number' && volTo >= 0) {
        this.output.gain.linearRampToValueAtTime(volTo, now + tFromNow + rampTime);
      } else {
        this.output.gain.linearRampToValueAtTime(vol, now + tFromNow + rampTime);
      }
    } else if (vol) {
      vol.connect(this.output.gain);
    } else {
      // return the Gain Node
      return this.output.gain;
    }
  };