code: function _computeDistanceOutsideRoom(distance) {
    // We apply a linear ramp from 1 to 0 as the source is up to 1m outside.
    let gain = 1;
    if (distance > Utils.EPSILON_FLOAT) {
      gain = 1 - distance / Utils.SOURCE_MAX_OUTSIDE_ROOM_DISTANCE;
  
      // Clamp gain between 0 and 1.
      gain = Math.max(0, Math.min(1, gain));
    }
    return gain;
  }
docs: Determine the distance a source is outside of a room. Attenuate gain going
  to the reflections and reverb when the source is outside of the room.
  @param {Number} distance Distance in meters.
  @return {Number} Gain (linear) of source.
  @private