Angle Computation in EdgeExpandedGraph/Assemble Steps doesn't match up

[MoKob]

osrm-backend/src/engine/guidance/assemble_steps.cpp

Lines 16 to 31 in 8aa93f3

	std::pair<short, short> getIntermediateBearings(const LegGeometry &leg_geometry,
	const std::size_t segment_index)
	{
	auto turn_index = leg_geometry.BackIndex(segment_index);
	BOOST_ASSERT(turn_index > 0);
	BOOST_ASSERT(turn_index + 1 < leg_geometry.locations.size());
	// TODO chose a bigger look-a-head to smooth complex geometry
	const auto pre_turn_coordinate = leg_geometry.locations[turn_index - 1];
	const auto turn_coordinate = leg_geometry.locations[turn_index];
	const auto post_turn_coordinate = leg_geometry.locations[turn_index + 1];
	return std::make_pair<short, short>(
	std::round(util::coordinate_calculation::bearing(pre_turn_coordinate, turn_coordinate)),
	std::round(util::coordinate_calculation::bearing(turn_coordinate, post_turn_coordinate)));
	}

calculates the bearings along the route based on the geometry.

This is ignoring all optimisations we could do in the creation of the edge based graphs

osrm-backend/src/extractor/guidance/intersection_generator.cpp

Lines 125 to 130 in 8aa93f3

	const auto first_coordinate = getRepresentativeCoordinate(
	from_node, turn_node, via_eid, INVERT, compressed_edge_container, node_info_list);
	const auto third_coordinate = getRepresentativeCoordinate(
	turn_node, to_node, onto_edge, !INVERT, compressed_edge_container, node_info_list);
	angle = util::coordinate_calculation::computeAngle(
	first_coordinate, node_info_list[turn_node], third_coordinate);

.

Right now the effects are limited, but

osrm-backend/include/util/guidance/bearing_class.hpp

Line 53 in 8aa93f3

std::size_t findMatchingBearing(const double bearing) const;

cannot work correctly if the turn angles differ a lot between the extraction/the post processing.