Added post process logic to collapse segregated turn instructions (#4925)

* Added post process logic to collapse segregated turn instructions * format updates * Fixed coordinates to reflect reality Updated left turn road name * fixed coordinates to fix test * Skip last step when processing segregated steps * updated segregated turn test * Updated segregated test * Updated test: Segregated Intersection, Cross Belonging to Correct Street - features/guidance/collapse.feature:79 * Fixed all but one for features/guidance/collapse.feature:124 * Fixed Scenario: Partly Segregated Intersection, Two Segregated Roads, Intersection belongs to Second - features/guidance/collapse.feature:219 * Fixed 7 of th 9 failures for Scenario: Partly Segregated Intersection, Two Segregated Roads, Intersection belongs to Second - features/guidance/collapse.feature:219 * Fixed 7 of the 9 failures for Scenario: Segregated Intersection, Cross Belonging to Mixed Streets - Slight Angles (2) - features/guidance/collapse.feature:318 * Fixed Scenario: Segregated Intersection into Slight Turn - features/guidance/collapse.feature:581 * Updated Scenario: U-turn after a traffic light - features/guidance/turn-lanes.feature:1220 * Updated how we combine segregated steps * Added test to Verify end of road left turn across divided roads * Fixed divided highwat tests * Fixed test failure * fixed Scenario: Partitioned turn, Slight Curve - maxspeed - features/guidance/turn-lanes.feature:936 * Fixed Scenario: Partitioned turn, Slight Curve - features/guidance/turn-lanes.feature:961 * Added strategies to combine segrgated intersections * Added setModifier alias for readability * Added strategies to combine segrgated intersections * Format updates * Fixes segregated indentification to not mark `circular` edge as segregated * Added intersection prior to turn so we still call out end of road * updated expectation to be turn instead of continue * Confirmed with @oxidase that the lane information if correct - updated the expectation * Added logic to handle wider straights Fixed tests * Update CHANGELOG.md Added #4925 * Removed TODO * Process straight step prior to wider straight step
2018-03-30 07:43:56 -04:00
parent 0d9f18fe1f
commit 8a63ad9b4b
11 changed files with 449 additions and 121 deletions
@@ -148,6 +148,9 @@ class RouteAPI : public BaseAPI
                // processing is performed
                guidance::applyOverrides(BaseAPI::facade, steps, leg_geometry);

+                // Collapse segregated steps before others
+                steps = guidance::collapseSegregatedTurnInstructions(std::move(steps));
+
                /* Perform step-based post-processing.
                 *
                 * Using post-processing on basis of route-steps for a single leg at a time
@@ -13,13 +13,19 @@ namespace engine
 namespace guidance
 {

+// Multiple possible reasons can result in unnecessary/confusing instructions
+// Collapsing such turns into a single turn instruction, we give a clearer
+// set of instructions that is not cluttered by unnecessary turns/name changes.
+OSRM_ATTR_WARN_UNUSED
+std::vector<RouteStep> collapseTurnInstructions(std::vector<RouteStep> steps);
+
 // Multiple possible reasons can result in unnecessary/confusing instructions
 // A prime example would be a segregated intersection. Turning around at this
 // intersection would result in two instructions to turn left.
 // Collapsing such turns into a single turn instruction, we give a clearer
-// set of instructionst that is not cluttered by unnecessary turns/name changes.
+// set of instructions that is not cluttered by unnecessary turns/name changes.
 OSRM_ATTR_WARN_UNUSED
-std::vector<RouteStep> collapseTurnInstructions(std::vector<RouteStep> steps);
+std::vector<RouteStep> collapseSegregatedTurnInstructions(std::vector<RouteStep> steps);

 // A combined turn is a set of two instructions that actually form a single turn, as far as we
 // perceive it. A u-turn consisting of two left turns is one such example. But there are also lots
@@ -93,6 +99,22 @@ struct StaggeredTurnStrategy : CombineStrategy
    const RouteStep &step_prior_to_intersection;
 };

+// Handling of consecutive segregated steps
+struct CombineSegregatedStepsStrategy : CombineStrategy
+{
+    void operator()(RouteStep &step_at_turn_location, const RouteStep &transfer_from_step) const;
+};
+
+// Handling of segregated intersections
+struct SegregatedTurnStrategy : CombineStrategy
+{
+    SegregatedTurnStrategy(const RouteStep &step_prior_to_intersection);
+
+    void operator()(RouteStep &step_at_turn_location, const RouteStep &transfer_from_step) const;
+
+    const RouteStep &step_prior_to_intersection;
+};
+
 // Signage Strategies

 // Transfer the signage from the next step onto this step
@@ -23,6 +23,7 @@ const constexpr std::size_t MIN_END_OF_ROAD_INTERSECTIONS = std::size_t{2};
 const constexpr double MAX_COLLAPSE_DISTANCE = 30.0;
 // a bit larger than 100 to avoid oscillation in tests
 const constexpr double NAME_SEGMENT_CUTOFF_LENGTH = 105.0;
+const double constexpr STRAIGHT_ANGLE = 180.;

 // check if a step is completely without turn type
 inline bool hasTurnType(const RouteStep &step)
@@ -104,6 +105,12 @@ inline void setInstructionType(RouteStep &step, const osrm::guidance::TurnType::
    step.maneuver.instruction.type = type;
 }

+// alias for readability
+inline void setModifier(RouteStep &step, const osrm::guidance::DirectionModifier::Enum modifier)
+{
+    step.maneuver.instruction.direction_modifier = modifier;
+}
+
 // alias for readability
 inline bool haveSameMode(const RouteStep &lhs, const RouteStep &rhs)
 {
@@ -215,6 +222,86 @@ inline double totalTurnAngle(const RouteStep &entry_step, const RouteStep &exit_
    return total_angle;
 }

+// check bearings for u-turns.
+// since bearings are wrapped around at 0 (we only support 0,360), we need to do some minor math to
+// check if bearings `a` and `b` go in opposite directions. In general we accept some minor
+// deviations for u-turns.
+inline bool bearingsAreReversed(const double bearing_in, const double bearing_out)
+{
+    // Nearly perfectly reversed angles have a difference close to 180 degrees (straight)
+    const double left_turn_angle = [&]() {
+        if (0 <= bearing_out && bearing_out <= bearing_in)
+            return bearing_in - bearing_out;
+        return bearing_in + 360 - bearing_out;
+    }();
+    return util::angularDeviation(left_turn_angle, 180) <= 35;
+}
+
+// Returns true if the specified step has only one intersection
+inline bool hasSingleIntersection(const RouteStep &step)
+{
+    return (step.intersections.size() == 1);
+}
+
+// Returns true if the specified angle is a wider straight turn
+inline bool isWiderStraight(const double angle) { return (angle >= 125 && angle <= 235); }
+
+// Returns the straightest intersecting edge turn for the specified step
+inline double getStraightestIntersectingEdgeTurn(const RouteStep &step)
+{
+    const auto &intersection = step.intersections.front();
+    const double bearing_in = util::bearing::reverse(intersection.bearings[intersection.in]);
+    double staightest_turn = 360.;
+    double staightest_delta = 360.;
+
+    for (std::size_t i = 0; i < intersection.bearings.size(); ++i)
+    {
+        // Skip the in, out, and non-traversable edges
+        if ((i == intersection.in) || (i == intersection.out) || !intersection.entry.at(i))
+            continue;
+
+        double intersecting_turn =
+            util::bearing::angleBetween(bearing_in, intersection.bearings.at(i));
+        double straight_delta = util::angularDeviation(intersecting_turn, STRAIGHT_ANGLE);
+
+        if (straight_delta < staightest_delta)
+        {
+            staightest_delta = straight_delta;
+            staightest_turn = intersecting_turn;
+        }
+    }
+    return staightest_turn;
+}
+
+// Returns true if the specified step has the straightest turn as compared to
+// the intersecting edges
+inline bool hasStraightestTurn(const RouteStep &step)
+{
+    const auto &intersection = step.intersections.front();
+    const double path_turn =
+        util::bearing::angleBetween(util::bearing::reverse(intersection.bearings[intersection.in]),
+                                    intersection.bearings[intersection.out]);
+
+    // Path turn must be a wider straight
+    if (isWiderStraight(path_turn))
+    {
+        const double straightest_intersecting_turn = getStraightestIntersectingEdgeTurn(step);
+        const double path_straight_delta = util::angularDeviation(path_turn, STRAIGHT_ANGLE);
+        const double intersecting_straight_delta =
+            util::angularDeviation(straightest_intersecting_turn, STRAIGHT_ANGLE);
+        const double path_intersecting_delta =
+            util::angularDeviation(path_turn, straightest_intersecting_turn);
+
+        // Add some fuzz - the delta between the path and intersecting turn must be greater
+        // than 10 in order to consider using the intersecting turn as the straightest
+        return ((path_intersecting_delta > 10.)
+                    ? (path_straight_delta <= intersecting_straight_delta)
+                    : true);
+    }
+
+    return false;
+}
+
 } /* namespace guidance */
 } /* namespace engine */
 } /* namespace osrm */