Method ScaleImpl

libs/drape_frontend/navigator.cpp:166–217

}

bool Navigator::ScaleImpl(m2::PointD const & newPt1, m2::PointD const & newPt2, m2::PointD const & oldPt1,
                          m2::PointD const & oldPt2, bool skipMinScaleAndBordersCheck, bool doRotateScreen,
                          ScreenBase & screen)
{
  m2::PointD const center3d = oldPt1;
  m2::PointD const center2d = screen.P3dtoP(center3d);
  m2::PointD const centerG = screen.PtoG(center2d);
  m2::PointD const offset = center2d - center3d;
  math::Matrix<double, 3, 3> const newM =
      screen.GtoPMatrix() * ScreenBase::CalcTransform(oldPt1 + offset, oldPt2 + offset, newPt1 + offset,
                                                      newPt2 + offset, doRotateScreen, true);
  ScreenBase tmp = screen;
  tmp.SetGtoPMatrix(newM);

  if (!CheckMaxScale(tmp))
  {
    if (doRotateScreen)
    {
      math::Matrix<double, 3, 3> const tmpM =
          screen.GtoPMatrix() * ScreenBase::CalcTransform(oldPt1 + offset, oldPt2 + offset, newPt1 + offset,
                                                          newPt2 + offset, doRotateScreen, false);
      tmp.SetGtoPMatrix(tmpM);
    }
    else
    {
      return false;
    }
  }

  if (tmp.isPerspective())
    tmp.MatchGandP3d(centerG, center3d);

  if (!skipMinScaleAndBordersCheck && !CheckMinScale(tmp))
    return false;

  m2::RectD const & worldR = df::GetWorldRect();

  if (!skipMinScaleAndBordersCheck && !CheckBorders(tmp))
  {
    if (CanShrinkInto(tmp, worldR))
      tmp = ShrinkInto(tmp, worldR);
    else
      return false;
  }

  // re-checking the borders, as we might violate them a bit (don't know why).
  if (!CheckBorders(tmp))
    tmp = ScaleInto(tmp, worldR);

  screen = tmp;
  return true;
}

void Navigator::DoScale(m2::PointD const & pt1, m2::PointD const & pt2)
{