Turn Angles in OSRM were computed using a lookahead of 10 meters.

This PR adds more advanced coordinate extraction, analysing the road
to detect offsets due to OSM way modelling.

In addition it improves the handling of bearings. Right now OSM reports
bearings simply based on the very first coordinate along a way.
With this PR, we store the bearings for a turn correctly, making the
bearings for turns correct.

include/engine/guidance/assemble_geometry.hpp

@@ -47,8 +47,8 @@ inline LegGeometry assembleGeometry(const datafacade::BaseDataFacade &facade,
     // TODO: check if this was traversed in reverse?
     const std::vector<NodeID> source_geometry =
         facade.GetUncompressedForwardGeometry(source_node.packed_geometry_id);
-    geometry.osm_node_ids.push_back(facade.GetOSMNodeIDOfNode(
-        source_geometry[source_node.fwd_segment_position]));
+    geometry.osm_node_ids.push_back(
+        facade.GetOSMNodeIDOfNode(source_geometry[source_node.fwd_segment_position]));
 
     auto cumulative_distance = 0.;
     auto current_distance = 0.;

include/engine/guidance/assemble_steps.hpp

@@ -33,8 +33,6 @@ namespace detail
 {
 std::pair<short, short> getDepartBearings(const LegGeometry &leg_geometry);
 std::pair<short, short> getArriveBearings(const LegGeometry &leg_geometry);
-std::pair<short, short> getIntermediateBearings(const LegGeometry &leg_geometry,
-                                                const std::size_t segment_index);
 } // ns detail
 
 inline std::vector<RouteStep> assembleSteps(const datafacade::BaseDataFacade &facade,
@@ -132,12 +130,14 @@ inline std::vector<RouteStep> assembleSteps(const datafacade::BaseDataFacade &fa
                     step_name_id = target_node.name_id;
                 }
 
-                bearings = detail::getIntermediateBearings(leg_geometry, segment_index);
+                // extract bearings
+                bearings = std::make_pair<std::uint16_t, std::uint16_t>(
+                    path_point.pre_turn_bearing.Get(), path_point.post_turn_bearing.Get());
                 const auto entry_class = facade.GetEntryClass(path_point.entry_classid);
                 const auto bearing_class =
                     facade.GetBearingClass(facade.GetBearingClassID(path_point.turn_via_node));
-                intersection.in = bearing_class.findMatchingBearing(
-                    util::bearing::reverseBearing(bearings.first));
+                auto bearing_data = bearing_class.getAvailableBearings();
+                intersection.in = bearing_class.findMatchingBearing(bearings.first);
                 intersection.out = bearing_class.findMatchingBearing(bearings.second);
                 intersection.location = facade.GetCoordinateOfNode(path_point.turn_via_node);
                 intersection.bearings.clear();
@@ -155,8 +155,10 @@ inline std::vector<RouteStep> assembleSteps(const datafacade::BaseDataFacade &fa
                 {
                     intersection.entry.push_back(entry_class.allowsEntry(idx));
                 }
+                std::int16_t bearing_in_driving_direction =
+                    util::bearing::reverseBearing(std::round(bearings.first));
                 maneuver = {intersection.location,
-                            bearings.first,
+                            bearing_in_driving_direction,
                             bearings.second,
                             path_point.turn_instruction,
                             WaypointType::None,