diff options
Diffstat (limited to 'boost/geometry/policies/relate/intersection_points.hpp')
| -rw-r--r-- | boost/geometry/policies/relate/intersection_points.hpp | 32 |
1 files changed, 29 insertions, 3 deletions
diff --git a/boost/geometry/policies/relate/intersection_points.hpp b/boost/geometry/policies/relate/intersection_points.hpp index 082dc4ca7f..50f9b43122 100644 --- a/boost/geometry/policies/relate/intersection_points.hpp +++ b/boost/geometry/policies/relate/intersection_points.hpp @@ -18,6 +18,7 @@ #include <boost/geometry/algorithms/detail/assign_indexed_point.hpp> #include <boost/geometry/core/access.hpp> +#include <boost/geometry/core/assert.hpp> #include <boost/geometry/strategies/side_info.hpp> #include <boost/geometry/util/promote_integral.hpp> #include <boost/geometry/util/select_calculation_type.hpp> @@ -60,7 +61,7 @@ struct segments_intersection_points // Up to now, division was postponed. Here we divide using numerator/ // denominator. In case of integer this results in an integer // division. - BOOST_ASSERT(ratio.denominator() != 0); + BOOST_GEOMETRY_ASSERT(ratio.denominator() != 0); typedef typename promote_integral<coordinate_type>::type promoted_type; @@ -81,7 +82,6 @@ struct segments_intersection_points >(numerator * dy_promoted / denominator)); } - template < typename Segment1, @@ -95,7 +95,33 @@ struct segments_intersection_points return_type result; result.count = 1; - if (sinfo.robust_ra < sinfo.robust_rb) + bool use_a = true; + + // Prefer one segment if one is on or near an endpoint + bool const a_near_end = sinfo.robust_ra.near_end(); + bool const b_near_end = sinfo.robust_rb.near_end(); + if (a_near_end && ! b_near_end) + { + use_a = true; + } + else if (b_near_end && ! a_near_end) + { + use_a = false; + } + else + { + // Prefer shorter segment + typedef typename SegmentIntersectionInfo::promoted_type ptype; + ptype const len_a = sinfo.dx_a * sinfo.dx_a + sinfo.dy_a * sinfo.dy_a; + ptype const len_b = sinfo.dx_b * sinfo.dx_b + sinfo.dy_b * sinfo.dy_b; + if (len_b < len_a) + { + use_a = false; + } + // else use_a is true but was already assigned like that + } + + if (use_a) { assign(result.intersections[0], s1, sinfo.robust_ra, sinfo.dx_a, sinfo.dy_a); |