protected void onHorizontalTranslateRel(
      Angle forwardChange, Angle sideChange, ViewInputAttributes.ActionAttributes actionAttribs) {
    View view = this.getView();
    if (view == null) // include this test to ensure any derived implementation performs it
    {
      return;
    }

    if (forwardChange.equals(Angle.ZERO) && sideChange.equals(Angle.ZERO)) {
      return;
    }

    if (view instanceof BasicFlyView) {

      Vec4 forward = view.getForwardVector();
      Vec4 up = view.getUpVector();
      Vec4 side = forward.transformBy3(Matrix.fromAxisAngle(Angle.fromDegrees(90), up));

      forward = forward.multiply3(forwardChange.getDegrees());
      side = side.multiply3(sideChange.getDegrees());
      Vec4 eyePoint = view.getEyePoint();
      eyePoint = eyePoint.add3(forward.add3(side));
      Position newPosition = view.getGlobe().computePositionFromPoint(eyePoint);

      this.setEyePosition(this.uiAnimControl, view, newPosition, actionAttribs);
      view.firePropertyChange(AVKey.VIEW, null, view);
    }
  }