actually calculate distance instead of using .distance which is a timing value

include/extractor/guidance/coordinate_extractor.hpp

@@ -40,6 +40,11 @@ class CoordinateExtractor
                                                           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)
+    std::vector<util::Coordinate> GetForwardCoordinatesAlongRoad(const NodeID from,
+                                                                 const EdgeID turn_edge) const;
+
     /* When extracting the coordinates, we first extract all coordinates. We don't care about most
      * of them, though.
      *

include/extractor/guidance/intersection_generator.hpp

@@ -47,6 +47,9 @@ class IntersectionGenerator
                                            NodeID *resulting_from_node,
                                            EdgeID *resulting_via_edge) const;
 
+    // Allow access to the coordinate extractor for all owners
+    const CoordinateExtractor &GetCoordinateExtractor() const;
+
   private:
     const util::NodeBasedDynamicGraph &node_based_graph;
     const RestrictionMap &restriction_map;

include/util/coordinate_calculation.hpp

@@ -5,7 +5,9 @@
 
 #include <boost/optional.hpp>
 
+#include <algorithm>
 #include <utility>
+#include <vector>
 
 namespace osrm
 {
@@ -30,6 +32,24 @@ double haversineDistance(const Coordinate first_coordinate, const Coordinate sec
 
 double greatCircleDistance(const Coordinate first_coordinate, const Coordinate second_coordinate);
 
+// get the length of a full coordinate vector, using one of our basic functions to compute distances
+template <class BinaryOperation>
+double getLength(const std::vector<Coordinate> &coordinates, BinaryOperation op)
+{
+    if (coordinates.empty())
+        return 0.;
+
+    double result = 0;
+    const auto functor = [&result, op](const Coordinate lhs, const Coordinate rhs) {
+        result += op(lhs, rhs);
+        return false;
+    };
+    // side-effect find adding up distances
+    std::adjacent_find(coordinates.begin(), coordinates.end(), functor);
+
+    return result;
+}
+
 // Find the closest distance and location between coordinate and the line connecting source and
 // target:
 //             coordinate