reduce numbers of intersections in findNextIntersection, don't normalise for turn lanes

include/extractor/guidance/coordinate_extractor.hpp

@@ -1,6 +1,7 @@
 #ifndef OSRM_EXTRACTOR_COORDINATE_EXTRACTOR_HPP_
 #define OSRM_EXTRACTOR_COORDINATE_EXTRACTOR_HPP_
 
+#include <utility>
 #include <vector>
 
 #include "extractor/compressed_edge_container.hpp"
@@ -28,6 +29,7 @@ class CoordinateExtractor
     /* Find a interpolated coordinate a long the compressed geometries. The desired coordinate
      * should be in a certain distance. This method is dedicated to find representative coordinates
      * at turns.
+     * Since we are computing the length of the segment anyhow, we also return it.
      */
     OSRM_ATTR_WARN_UNUSED
     util::Coordinate GetCoordinateAlongRoad(const NodeID intersection_node,
@@ -36,12 +38,23 @@ class CoordinateExtractor
                                             const NodeID to_node,
                                             const std::uint8_t number_of_in_lanes) const;
 
-    // instead of finding only a single coordinate, we can also list all coordinates along a road.
+    // same as above, only with precomputed coordinate vector (move it in)
     OSRM_ATTR_WARN_UNUSED
-    std::vector<util::Coordinate> GetCoordinatesAlongRoad(const NodeID intersection_node,
-                                                          const EdgeID turn_edge,
-                                                          const bool traversed_in_reverse,
-                                                          const NodeID to_node) const;
+    util::Coordinate
+    ExtractRepresentativeCoordinate(const NodeID intersection_node,
+                                    const EdgeID turn_edge,
+                                    const bool traversed_in_reverse,
+                                    const NodeID to_node,
+                                    const std::uint8_t intersection_lanes,
+                                    std::vector<util::Coordinate> coordinates) const;
+
+    // instead of finding only a single coordinate, we can also list all coordinates along a
+    // road.
+    OSRM_ATTR_WARN_UNUSED std::vector<util::Coordinate>
+    GetCoordinatesAlongRoad(const NodeID intersection_node,
+                            const EdgeID turn_edge,
+                            const bool traversed_in_reverse,
+                            const NodeID to_node) const;
 
     // wrapper in case of normal forward edges (traversed_in_reverse = false, to_node =
     // node_based_graph.GetTarget(turn_edge)

include/extractor/guidance/intersection.hpp

@@ -9,6 +9,8 @@
 #include "util/node_based_graph.hpp"
 #include "util/typedefs.hpp" // EdgeID
 
+#include <boost/optional.hpp>
+
 namespace osrm
 {
 namespace extractor
@@ -53,10 +55,13 @@ struct ConnectedRoad final : public TurnOperation
 {
     using Base = TurnOperation;
 
-    ConnectedRoad(const TurnOperation turn, const bool entry_allowed = false);
+    ConnectedRoad(const TurnOperation turn,
+                  const bool entry_allowed = false,
+                  const boost::optional<double> segment_length = {});
 
     // a turn may be relevant to good instructions, even if we cannot enter the road
     bool entry_allowed;
+    boost::optional<double> segment_length;
 
     // used to sort the set of connected roads (we require sorting throughout turn handling)
     bool compareByAngle(const ConnectedRoad &other) const;

include/extractor/guidance/turn_analysis.hpp

@@ -68,6 +68,9 @@ class TurnAnalysis
     std::vector<TurnOperation>
     transformIntersectionIntoTurns(const Intersection &intersection) const;
 
+    Intersection
+    assignTurnTypes(const NodeID from_node, const EdgeID via_eid, Intersection intersection) const;
+
     const IntersectionGenerator &GetIntersectionGenerator() const;
 
   private:
@@ -79,9 +82,6 @@ class TurnAnalysis
     const TurnHandler turn_handler;
     const SliproadHandler sliproad_handler;
 
-    Intersection
-    assignTurnTypes(const NodeID from_node, const EdgeID via_eid, Intersection intersection) const;
-
     // Utility function, setting basic turn types. Prepares for normal turn handling.
     Intersection
     setTurnTypes(const NodeID from, const EdgeID via_edge, Intersection intersection) const;

include/extractor/guidance/turn_discovery.hpp

@@ -22,7 +22,7 @@ namespace lanes
 bool findPreviousIntersection(
     const NodeID node,
     const EdgeID via_edge,
-    const Intersection intersection,
+    const Intersection &intersection,
     const IntersectionGenerator &intersection_generator,
     const util::NodeBasedDynamicGraph &node_based_graph, // query edge data
     // output parameters, will be in an arbitrary state on failure