[geometry] Use robust_policy in append_no_dups_or_spikes

Only if robust_policy would make any difference, so we added an "enabled"
boolean into the policy

include/boost/geometry/algorithms/detail/overlay/append_no_dups_or_spikes.hpp

@@ -24,37 +24,118 @@ namespace boost { namespace geometry
 namespace detail { namespace overlay
 {
 
-template <typename Range, typename Point, typename RobustPolicys>
+// TODO: move this / rename this
+template <typename Point1, typename Point2, typename RobustPolicy>
+inline bool points_equal_or_close(Point1 const& point1,
+        Point2 const& point2,
+        RobustPolicy const& robust_policy)
+{
+    if (detail::equals::equals_point_point(point1, point2))
+    {
+        return true;
+    }
+
+    if (! RobustPolicy::enabled)
+    {
+        return false;
+    }
+
+    // Try using specified robust policy
+    typedef typename geometry::robust_point_type
+    <
+        Point1,
+        RobustPolicy
+    >::type robust_point_type;
+
+    robust_point_type point1_rob, point2_rob;
+    geometry::recalculate(point1_rob, point1, robust_policy);
+    geometry::recalculate(point2_rob, point2, robust_policy);
+
+    return detail::equals::equals_point_point(point1_rob, point2_rob);
+}
+
+
+template <typename Range, typename Point, typename RobustPolicy>
 inline void append_no_dups_or_spikes(Range& range, Point const& point,
-        RobustPolicys const& robust_policy)
+        RobustPolicy const& robust_policy)
 {
 #ifdef BOOST_GEOMETRY_DEBUG_INTERSECTION
     std::cout << "  add: ("
         << geometry::get<0>(point) << ", " << geometry::get<1>(point) << ")"
         << std::endl;
 #endif
-    boost::ignore_unused_variable_warning(robust_policy);
+    // The code below thies condition checks all spikes/dups
+    // for geometries >= 3 points.
+    // So we have to check the first potential duplicate differently
+    if (boost::size(range) == 1
+        && points_equal_or_close(*(boost::begin(range)), point, robust_policy))
+    {
+        return;
+    }
 
     traits::push_back<Range>::apply(range, point);
 
-    // If a point is equal, or forming a spike, remove the pen-ultimate point because this one caused the spike.
-    // If so, the now-new-pen-ultimate point can again cause a spike (possibly at a corner). So keep doing this.
-    // Besides spikes it will also avoid duplicates.
+    // If a point is equal, or forming a spike, remove the pen-ultimate point
+    // because this one caused the spike.
+    // If so, the now-new-pen-ultimate point can again cause a spike
+    // (possibly at a corner). So keep doing this.
+    // Besides spikes it will also avoid adding duplicates.
     while(boost::size(range) >= 3
-            && point_is_spike_or_equal(point, *(boost::end(range) - 3), *(boost::end(range) - 2)))
+            && point_is_spike_or_equal(point,
+                *(boost::end(range) - 3),
+                *(boost::end(range) - 2),
+                robust_policy))
     {
         // Use the Concept/traits, so resize and append again
         traits::resize<Range>::apply(range, boost::size(range) - 2);
         traits::push_back<Range>::apply(range, point);
     }
+}
 
-    // There might still be one duplicate not catched by the condition above
-    if (boost::size(range) == 2
-        && geometry::detail::equals::equals_point_point(*boost::begin(range), point))
+template <typename Range, typename RobustPolicy>
+inline void clean_closing_dups_and_spikes(Range& range,
+                RobustPolicy const& robust_policy)
+{
+    int const minsize
+        = core_detail::closure::minimum_ring_size
+            <
+                geometry::closure<Range>::value
+            >::value;
+
+    if (boost::size(range) <= minsize)
     {
-        traits::clear<Range>::apply(range);
-        traits::push_back<Range>::apply(range, point);
+        return;
     }
+
+    typedef typename boost::range_iterator<Range>::type iterator_type;
+    const bool closed = geometry::closure<Range>::value == geometry::closed;
+    bool found = false;
+    do
+    {
+        found = false;
+        iterator_type first = boost::begin(range);
+        iterator_type second = first + 1;
+        iterator_type ultimate = boost::end(range) - 1;
+        if (closed)
+        {
+            ultimate--;
+        }
+
+        // Check if closing point is a spike (this is so if the second point is
+        // considered as a spike w.r.t. the last segment)
+        if (point_is_spike_or_equal(*second, *ultimate, *first, robust_policy))
+        {
+            range.erase(first);
+            if (closed)
+            {
+                // Remove closing last point
+                traits::resize<Range>::apply(range, boost::size(range) - 1);
+                // Add new closing point
+                traits::push_back<Range>::apply(range, *boost::begin(range));
+            }
+            found = true;
+        }
+    } while(found && boost::size(range) > minsize);
 }
 
 

include/boost/geometry/algorithms/detail/overlay/traverse.hpp

@@ -399,9 +399,7 @@ public :
                                     detail::overlay::debug_traverse(*current, *iit, "->Finished");
                                     if (geometry::num_points(current_output) >= min_num_points)
                                     {
-                                        // TODO this call should go, it should already be clean from dups/spikes
-                                        clean_dups_and_spikes(current_output, rescale_policy);
-                                        // END TODO
+                                        clean_closing_dups_and_spikes(current_output, rescale_policy);
                                         rings.push_back(current_output);
                                     }
                                 }

include/boost/geometry/algorithms/detail/point_is_spike_or_equal.hpp

@@ -25,8 +25,18 @@ namespace boost { namespace geometry
 namespace detail
 {
 
+// Checks if a point ("last_point") causes a spike w.r.t.
+// the specified two other points (segment_a, segment_b)
+//
+//  x-------x------x
+//  a       lp     b
+//
+// Above, lp generates a spike w.r.t. segment(a,b)
+// So specify last point first, then (a,b) (this is unordered, so unintuitive)
 template <typename Point1, typename Point2, typename Point3>
-static inline bool point_is_spike_or_equal(Point1 const& last_point, Point2 const& segment_a, Point3 const& segment_b)
+static inline bool point_is_spike_or_equal(Point1 const& last_point,
+            Point2 const& segment_a,
+            Point3 const& segment_b)
 {
     typedef typename strategy::side::services::default_strategy
     <
@@ -62,6 +72,49 @@ static inline bool point_is_spike_or_equal(Point1 const& last_point, Point2 cons
     return false;
 }
 
+template
+<
+    typename Point1,
+    typename Point2,
+    typename Point3,
+    typename RobustPolicy
+>
+static inline bool point_is_spike_or_equal(Point1 const& last_point,
+            Point2 const& segment_a,
+            Point3 const& segment_b,
+            RobustPolicy const& robust_policy)
+{
+    if (point_is_spike_or_equal(last_point, segment_a, segment_b))
+    {
+        return true;
+    }
+
+    if (! RobustPolicy::enabled)
+    {
+        return false;
+    }
+
+    // Try using specified robust policy
+    typedef typename geometry::robust_point_type
+    <
+        Point1,
+        RobustPolicy
+    >::type robust_point_type;
+
+    robust_point_type last_point_rob, segment_a_rob, segment_b_rob;
+    geometry::recalculate(last_point_rob, last_point, robust_policy);
+    geometry::recalculate(segment_a_rob, segment_a, robust_policy);
+    geometry::recalculate(segment_b_rob, segment_b, robust_policy);
+
+    return point_is_spike_or_equal
+        (
+            last_point_rob,
+            segment_a_rob,
+            segment_b_rob
+        );
+}
+
+
 } // namespace detail
 #endif
 

include/boost/geometry/policies/robustness/no_rescale_policy.hpp

@@ -29,6 +29,8 @@ namespace detail
 // Probably this will be moved out of namespace detail
 struct no_rescale_policy
 {
+    static bool const enabled = false;
+
     // We don't rescale but return the reference of the input
     template <std::size_t Dimension, typename Value>
     inline Value const& apply(Value const& value) const

include/boost/geometry/policies/robustness/zoom_to_robust.hpp

@@ -59,6 +59,8 @@ struct get_max_size<Box, 0>
 template <typename FpPoint, typename IntPoint, typename CalculationType>
 struct rescale_strategy
 {
+    static bool const enabled = true;
+
     typedef typename geometry::coordinate_type<IntPoint>::type output_ct;
 
     rescale_strategy(FpPoint const& fp_min, IntPoint const& int_min, CalculationType const& the_factor)