Method ResolveTileKeys

libs/drape_frontend/frontend_renderer.cpp:2218–2267

}

TTilesCollection FrontendRenderer::ResolveTileKeys(ScreenBase const & screen)
{
  m2::RectD rect = screen.ClipRect();
  double const vs = VisualParams::Instance().GetVisualScale();
  double const extension = vs * dp::kScreenPixelRectExtension * screen.GetScale();
  rect.Inflate(extension, extension);
  int const dataZoomLevel = ClipTileZoomByMaxDataZoom(GetCurrentZoom());

  m_notFinishedTiles.clear();

  // Request new tiles.
  TTilesCollection tiles;
  /// @todo Introduce small_set class based on buffer_vector.
  buffer_vector<TileKey, 8> tilesToDelete;
  auto const result = CalcTilesCoverage(rect, dataZoomLevel, [this, &rect, &tiles, &tilesToDelete](int tileX, int tileY)
  {
    TileKey const key(tileX, tileY, GetCurrentZoom());
    if (rect.IsIntersect(key.GetGlobalRect()))
    {
      tiles.insert(key);
      m_notFinishedTiles.insert(key);
    }
    else
    {
      tilesToDelete.push_back(key);
    }
  });

  // Remove old tiles.
  auto removePredicate = [this, &result, &tilesToDelete](drape_ptr<RenderGroup> const & group)
  {
    TileKey const & key = group->GetTileKey();
    return key.m_zoomLevel == GetCurrentZoom() &&
           (key.m_x < result.m_minTileX || key.m_x >= result.m_maxTileX || key.m_y < result.m_minTileY ||
            key.m_y >= result.m_maxTileY || base::IsExist(tilesToDelete, key));
  };
  for (RenderLayer & layer : m_layers)
    layer.m_isDirty |= RemoveGroups(removePredicate, layer.m_renderGroups, make_ref(m_overlayTree));

  RemoveRenderGroupsLater([this](drape_ptr<RenderGroup> const & group)
  { return group->GetTileKey().m_zoomLevel != GetCurrentZoom(); });

  m_trafficRenderer->OnUpdateViewport(result, GetCurrentZoom(), tilesToDelete);

#if defined(DRAPE_MEASURER_BENCHMARK) && defined(GENERATING_STATISTIC)
  DrapeMeasurer::Instance().StartScenePreparing();
#endif

  return tiles;
}

void FrontendRenderer::OnContextDestroy()
{