Return an array with meta-data for each coordinate.

Currently supports duration and distance for each coordinate.

This is particularly useful in map-matching, comparing how
a trip progresses compared to a real GPS trace that is
map-matched.

include/engine/guidance/assemble_geometry.hpp

@@ -43,34 +43,40 @@ LegGeometry assembleGeometry(const DataFacadeT &facade,
     geometry.segment_offsets.push_back(0);
     geometry.locations.push_back(source_node.location);
 
+    auto cumulative_distance = 0.;
     auto current_distance = 0.;
     auto prev_coordinate = geometry.locations.front();
     for (const auto &path_point : leg_data)
     {
         auto coordinate = facade.GetCoordinateOfNode(path_point.turn_via_node);
-        current_distance +=
+        current_distance =
             util::coordinate_calculation::haversineDistance(prev_coordinate, coordinate);
+        cumulative_distance += current_distance;
 
         // all changes to this check have to be matched with assemble_steps
         if (path_point.turn_instruction.type != extractor::guidance::TurnType::NoTurn)
         {
-            geometry.segment_distances.push_back(current_distance);
+            geometry.segment_distances.push_back(cumulative_distance);
             geometry.segment_offsets.push_back(geometry.locations.size());
-            current_distance = 0.;
+            cumulative_distance = 0.;
         }
 
         prev_coordinate = coordinate;
+        geometry.annotations.emplace_back(LegGeometry::Annotation{current_distance, path_point.duration_until_turn / 10.});
         geometry.locations.push_back(std::move(coordinate));
     }
-    current_distance +=
+    current_distance =
         util::coordinate_calculation::haversineDistance(prev_coordinate, target_node.location);
+    cumulative_distance += current_distance;
     // segment leading to the target node
-    geometry.segment_distances.push_back(current_distance);
+    geometry.segment_distances.push_back(cumulative_distance);
+    geometry.annotations.emplace_back(LegGeometry::Annotation{current_distance, target_node.forward_weight / 10.});
     geometry.segment_offsets.push_back(geometry.locations.size());
     geometry.locations.push_back(target_node.location);
 
     BOOST_ASSERT(geometry.segment_distances.size() == geometry.segment_offsets.size() - 1);
     BOOST_ASSERT(geometry.locations.size() > geometry.segment_distances.size());
+    BOOST_ASSERT(geometry.annotations.size() == geometry.locations.size() - 1);
 
     return geometry;
 }

include/engine/guidance/leg_geometry.hpp

@@ -31,6 +31,13 @@ struct LegGeometry
     // length of the segment in meters
     std::vector<double> segment_distances;
 
+    // Per-coordinate metadata
+    struct Annotation {
+        double distance;
+        double duration;
+    };
+    std::vector<Annotation> annotations;
+
     std::size_t FrontIndex(std::size_t segment_index) const
     {
         return segment_offsets[segment_index];