Method RecacheDebugLabels

libs/drape_frontend/gui/layer_render.cpp:252–335

#ifdef RENDER_DEBUG_INFO_LABELS
drape_ptr<LayerRenderer> LayerCacher::RecacheDebugLabels(ref_ptr<dp::GraphicsContext> context,
                                                         ref_ptr<dp::TextureManager> textures)
{
  drape_ptr<LayerRenderer> renderer = make_unique_dp<LayerRenderer>();

  auto const vs = static_cast<float>(df::VisualParams::Instance().GetVisualScale());
  DebugInfoLabels debugLabels = DebugInfoLabels(Position(m2::PointF(10.0f * vs, 50.0f * vs), dp::Center));

  debugLabels.AddLabel(textures,
                       "visible: km2, readed: km2, ratio:", [](ScreenBase const & screen, std::string & content) -> bool
  {
    double const sizeX = screen.PixelRectIn3d().SizeX();
    double const sizeY = screen.PixelRectIn3d().SizeY();

    m2::PointD const p0 = screen.PtoG(screen.P3dtoP(m2::PointD(0.0, 0.0)));
    m2::PointD const p1 = screen.PtoG(screen.P3dtoP(m2::PointD(0.0, sizeY)));
    m2::PointD const p2 = screen.PtoG(screen.P3dtoP(m2::PointD(sizeX, sizeY)));
    m2::PointD const p3 = screen.PtoG(screen.P3dtoP(m2::PointD(sizeX, 0.0)));

    double const areaG = mercator::AreaOnEarth(p0, p1, p2) + mercator::AreaOnEarth(p2, p3, p0);

    double const sizeX_2d = screen.PixelRect().SizeX();
    double const sizeY_2d = screen.PixelRect().SizeY();

    m2::PointD const p0_2d = screen.PtoG(m2::PointD(0.0, 0.0));
    m2::PointD const p1_2d = screen.PtoG(m2::PointD(0.0, sizeY_2d));
    m2::PointD const p2_2d = screen.PtoG(m2::PointD(sizeX_2d, sizeY_2d));
    m2::PointD const p3_2d = screen.PtoG(m2::PointD(sizeX_2d, 0.0));

    double const areaGTotal = mercator::AreaOnEarth(p0_2d, p1_2d, p2_2d) + mercator::AreaOnEarth(p2_2d, p3_2d, p0_2d);

    std::ostringstream out;
    out << std::fixed << std::setprecision(2) << "visible: " << areaG / 1000000.0 << " km2"
        << ", readed: " << areaGTotal / 1000000.0 << " km2"
        << ", ratio: " << areaGTotal / areaG;
    content.assign(out.str());
    return true;
  });

  debugLabels.AddLabel(textures, "scale2d: m/px, scale2d * vs: m/px",
                       [](ScreenBase const & screen, std::string & content) -> bool
  {
    double const distanceG = mercator::DistanceOnEarth(screen.PtoG(screen.PixelRect().LeftBottom()),
                                                       screen.PtoG(screen.PixelRect().RightBottom()));

    double const vs = df::VisualParams::Instance().GetVisualScale();
    double const scale = distanceG / screen.PixelRect().SizeX();

    std::ostringstream out;
    out << std::fixed << std::setprecision(2) << "scale2d: " << scale << " m/px"
        << ", scale2d * vs: " << scale * vs << " m/px";
    content.assign(out.str());
    return true;
  });

  debugLabels.AddLabel(textures, "distance: m", [](ScreenBase const & screen, std::string & content) -> bool
  {
    double const sizeX = screen.PixelRectIn3d().SizeX();