Function ApplyScale

libs/drape_frontend/screen_operations.cpp:224–259

}

bool ApplyScale(m2::PointD const & pixelScaleCenter, double factor, ScreenBase & screen)
{
  m2::PointD const globalScaleCenter = screen.PtoG(screen.P3dtoP(pixelScaleCenter));

  ScreenBase tmp = screen;
  tmp.Scale(factor);
  tmp.MatchGandP3d(globalScaleCenter, pixelScaleCenter);

  if (!CheckMinScale(tmp))
    return false;

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

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

  if (!CheckMaxScale(tmp))
  {
    auto const maxScale = GetScreenScale(scales::GetUpperStyleScale() + 0.42);
    if (maxScale > screen.GetScale() && CheckMaxScale(screen))
      return false;
    tmp.SetScale(maxScale);
  }

  // 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;
}

}  // namespace df