Moving the extrapolator to RoutingManager switching it on only for car and bicycle following mode.

map/extrapolation/extrapolator.cpp

@@ -62,7 +62,9 @@ location::GpsInfo LinearExtrapolation(location::GpsInfo const & gpsInfo1,
   // @TODO(bykoianko) Now |result.m_bearing == gpsInfo2.m_bearing|.
   // In case of |gpsInfo1.HasBearing() && gpsInfo2.HasBearing() == true|
   // consider finding an average value between |gpsInfo1.m_bearing| and |gpsInfo2.m_bearing|
-  // taking into account that they are periodic.
+  // taking into account that they are periodic. It's important to implement it
+  // because current implementation leads to changing course by steps. It doesn't
+  // look nice when the road changes its direction.
 
   if (gpsInfo1.HasSpeed() && gpsInfo2.HasSpeed())
     result.m_speed = e.Extrapolate(gpsInfo1.m_speed, gpsInfo2.m_speed);
@@ -72,7 +74,7 @@ location::GpsInfo LinearExtrapolation(location::GpsInfo const & gpsInfo1,
 
 // Extrapolator ------------------------------------------------------------------------------------
 Extrapolator::Extrapolator(ExtrapolatedLocationUpdateFn const & update)
-  : m_extrapolatedLocationUpdate(update)
+  : m_isEnabled(false), m_extrapolatedLocationUpdate(update)
 {
   GetPlatform().RunTask(Platform::Thread::Background, [this]
   {
@@ -82,12 +84,20 @@ Extrapolator::Extrapolator(ExtrapolatedLocationUpdateFn const & update)
 
 void Extrapolator::OnLocationUpdate(location::GpsInfo const & gpsInfo)
 {
+  // @TODO Consider calling ExtrapolatedLocationUpdate() on background thread immediately
+  // after OnLocationUpdate() was called.
   lock_guard<mutex> guard(m_mutex);
   m_beforeLastGpsInfo = m_lastGpsInfo;
   m_lastGpsInfo = gpsInfo;
   m_extrapolationCounter = 0;
 }
 
+void Extrapolator::Enable(bool enabled)
+{
+  lock_guard<mutex> guard(m_mutex);
+  m_isEnabled = enabled;
+}
+
 void Extrapolator::ExtrapolatedLocationUpdate()
 {
   location::GpsInfo gpsInfo;
@@ -135,7 +145,7 @@ bool Extrapolator::DoesExtrapolationWork(uint64_t extrapolationTimeMs) const
   // It may happen in rare cases because GpsInfo::m_timestamp is not monotonic generally.
   // Please see comment in declaration of class GpsInfo for details.
 
-  if (m_extrapolationCounter == m_extrapolationCounterUndefined ||
+  if (!m_isEnabled || m_extrapolationCounter == m_extrapolationCounterUndefined ||
       !m_lastGpsInfo.IsValid() || !m_beforeLastGpsInfo.IsValid() ||
       m_beforeLastGpsInfo.m_timestamp >= m_lastGpsInfo.m_timestamp)
   {

map/extrapolation/extrapolator.hpp

@@ -29,10 +29,15 @@ public:
   // @TODO(bykoianko) Gyroscope information should be taken into account as well for calculation
   // extrapolated position.
 
-  void ExtrapolatedLocationUpdate();
+  void Enable(bool enabled);
 
 private:
+  /// \returns true if there's enough information for extrapolation and extrapolation is enabled.
+  /// \note This method should be called only when |m_mutex| is locked.
   bool DoesExtrapolationWork(uint64_t extrapolationTimeMs) const;
+  void ExtrapolatedLocationUpdate();
+
+  bool m_isEnabled;
 
   std::mutex m_mutex;
   ExtrapolatedLocationUpdateFn m_extrapolatedLocationUpdate;

map/framework.cpp

@@ -216,7 +216,7 @@ void Framework::OnLocationUpdate(GpsInfo const & info)
   GpsInfo rInfo(info);
 #endif
 
-  m_extrapolator.OnLocationUpdate(rInfo);
+  m_routingManager.OnLocationUpdate(rInfo);
 }
 
 void Framework::OnCompassUpdate(CompassInfo const & info)
@@ -367,9 +367,6 @@ Framework::Framework(FrameworkParams const & params)
             },
             [this]() -> StringsBundle const & { return m_stringsBundle; }),
         static_cast<RoutingManager::Delegate &>(*this))
-  , m_extrapolator([this](location::GpsInfo const & gpsInfo) {
-    this->GetRoutingManager().OnLocationUpdate(gpsInfo);
-  })
   , m_trafficManager(bind(&Framework::GetMwmsByRect, this, _1, false /* rough */),
                      kMaxTrafficCacheSizeBytes, m_routingManager.RoutingSession())
   , m_bookingFilterProcessor(m_model.GetIndex(), *m_bookingApi)

map/framework.hpp

@@ -7,7 +7,6 @@
 #include "map/bookmark_manager.hpp"
 #include "map/discovery/discovery_manager.hpp"
 #include "map/displacement_mode_manager.hpp"
-#include "map/extrapolation/extrapolator.hpp"
 #include "map/feature_vec_model.hpp"
 #include "map/local_ads_manager.hpp"
 #include "map/mwm_url.hpp"
@@ -208,7 +207,6 @@ protected:
 
   // Note. |m_routingManager| should be declared before |m_trafficManager|
   RoutingManager m_routingManager;
-  extrapolation::Extrapolator m_extrapolator;
 
   TrafficManager m_trafficManager;
 

map/routing_manager.cpp

@@ -220,6 +220,8 @@ RoutingManager::RoutingManager(Callbacks && callbacks, Delegate & delegate)
   , m_delegate(delegate)
   , m_trackingReporter(platform::CreateSocket(), TRACKING_REALTIME_HOST, TRACKING_REALTIME_PORT,
                        tracking::Reporter::kPushDelayMs)
+  , m_extrapolator(
+        [this](location::GpsInfo const & gpsInfo) { this->OnExtrapolatedLocationUpdate(gpsInfo); })
   , m_transitReadManager(m_callbacks.m_indexGetter(), m_callbacks.m_readFeaturesFn)
 {
   auto const routingStatisticsFn = [](map<string, string> const & statistics) {
@@ -327,6 +329,11 @@ void RoutingManager::OnRoutePointPassed(RouteMarkType type, size_t intermediateI
   SaveRoutePoints();
 }
 
+void RoutingManager::OnLocationUpdate(location::GpsInfo const & info)
+{
+  m_extrapolator.OnLocationUpdate(info);
+}
+
 RouterType RoutingManager::GetBestRouter(m2::PointD const & startPoint,
                                          m2::PointD const & finalPoint) const
 {
@@ -557,6 +564,8 @@ void RoutingManager::FollowRoute()
   if (!m_routingSession.EnableFollowMode())
     return;
 
+  // Switching on the extrapolatior only for following mode in car and bicycle navigation.
+  m_extrapolator.Enable(m_currentRouterType == RouterType::Vehicle || m_currentRouterType == RouterType::Bicycle);
   m_delegate.OnRouteFollow(m_currentRouterType);
 
   HideRoutePoint(RouteMarkType::Start);
@@ -567,6 +576,7 @@ void RoutingManager::FollowRoute()
 
 void RoutingManager::CloseRouting(bool removeRoutePoints)
 {
+  m_extrapolator.Enable(false);
   // Hide preview.
   HidePreviewSegments();
   
@@ -918,20 +928,6 @@ void RoutingManager::MatchLocationToRoute(location::GpsInfo & location,
   m_routingSession.MatchLocationToRoute(location, routeMatchingInfo);
 }
 
-void RoutingManager::OnLocationUpdate(location::GpsInfo const & info)
-{
-  location::GpsInfo gpsInfo(info);
-  if (!m_drapeEngine)
-    m_gpsInfoCache = my::make_unique<location::GpsInfo>(gpsInfo);
-
-  auto routeMatchingInfo = GetRouteMatchingInfo(gpsInfo);
-  m_drapeEngine.SafeCall(&df::DrapeEngine::SetGpsInfo, gpsInfo,
-                         m_routingSession.IsNavigable(), routeMatchingInfo);
-
-  if (IsTrackingReporterEnabled())
-    m_trackingReporter.AddLocation(gpsInfo, m_routingSession.MatchTraffic(routeMatchingInfo));
-}
-
 location::RouteMatchingInfo RoutingManager::GetRouteMatchingInfo(location::GpsInfo & info)
 {
   location::RouteMatchingInfo routeMatchingInfo;
@@ -1243,6 +1239,20 @@ vector<RouteMarkData> RoutingManager::GetRoutePointsToSave() const
   return result;
 }
 
+void RoutingManager::OnExtrapolatedLocationUpdate(location::GpsInfo const & info)
+{
+  location::GpsInfo gpsInfo(info);
+  if (!m_drapeEngine)
+    m_gpsInfoCache = my::make_unique<location::GpsInfo>(gpsInfo);
+
+  auto routeMatchingInfo = GetRouteMatchingInfo(gpsInfo);
+  m_drapeEngine.SafeCall(&df::DrapeEngine::SetGpsInfo, gpsInfo,
+                         m_routingSession.IsNavigable(), routeMatchingInfo);
+
+  if (IsTrackingReporterEnabled())
+    m_trackingReporter.AddLocation(gpsInfo, m_routingSession.MatchTraffic(routeMatchingInfo));
+}
+
 void RoutingManager::DeleteSavedRoutePoints()
 {
   if (!HasSavedRoutePoints())

map/routing_manager.hpp

@@ -1,6 +1,7 @@
 #pragma once
 
 #include "map/bookmark_manager.hpp"
+#include "map/extrapolation/extrapolator.hpp"
 #include "map/routing_mark.hpp"
 #include "map/transit/transit_display.hpp"
 #include "map/transit/transit_reader.hpp"
@@ -281,6 +282,8 @@ private:
 
   std::vector<RouteMarkData> GetRoutePointsToSave() const;
 
+  void OnExtrapolatedLocationUpdate(location::GpsInfo const & info);
+
   RouteBuildingCallback m_routingCallback = nullptr;
   RouteRecommendCallback m_routeRecommendCallback = nullptr;
   Callbacks m_callbacks;
@@ -291,6 +294,7 @@ private:
   Delegate & m_delegate;
   tracking::Reporter m_trackingReporter;
   BookmarkManager * m_bmManager = nullptr;
+  extrapolation::Extrapolator m_extrapolator;
 
   std::vector<dp::DrapeID> m_drapeSubroutes;
   mutable std::mutex m_drapeSubroutesMutex;