Method PrepareRouteArrows

libs/drape_frontend/route_renderer.cpp:243–279

}

void RouteRenderer::PrepareRouteArrows(ScreenBase const & screen, PrepareRouteArrowsCallback const & prepareCallback)
{
  for (auto & subrouteInfo : m_subroutes)
  {
    // Interpolate values by zoom level.
    double zoom = 0.0;
    float halfWidth = 0.0;
    InterpolateByZoom(subrouteInfo.m_subroute, screen, halfWidth, zoom);
    subrouteInfo.m_baseHalfWidth = halfWidth;

    if (zoom < kArrowAppearingZoomLevel)
    {
      subrouteInfo.m_arrowsData.reset();
      subrouteInfo.m_arrowBorders.clear();
      continue;
    }

    // Calculate arrow borders.
    double dist = kInvalidDistance;
    if (m_followingEnabled)
      dist = m_distanceFromBegin - subrouteInfo.m_subroute->m_baseDistance;

    // We run asynchronous task to calculate new positions of route arrows.
    auto const subrouteId = subrouteInfo.m_subrouteId;
    auto const screenRect = screen.ClipRect();
    auto const screenScale = screen.GetScale();
    auto const subrouteLength = subrouteInfo.m_length;
    auto subroute = subrouteInfo.m_subroute;
    dp::DrapeRoutine::RunSequential([subrouteId, screenRect, screenScale, halfWidth, subroute = std::move(subroute),
                                     subrouteLength, dist, prepareCallback]()
    {
      ASSERT(prepareCallback != nullptr, ());
      prepareCallback(subrouteId,
                      CalculateArrowBorders(screenRect, screenScale, halfWidth, subroute, subrouteLength, dist));
    });
  }
}

void RouteRenderer::CacheRouteArrows(ScreenBase const & screen, dp::DrapeID subrouteId,
                                     std::vector<ArrowBorders> && arrowBorders,