diff options
Diffstat (limited to 'boost/geometry/algorithms/detail/point_is_spike_or_equal.hpp')
| -rw-r--r-- | boost/geometry/algorithms/detail/point_is_spike_or_equal.hpp | 46 |
1 files changed, 27 insertions, 19 deletions
diff --git a/boost/geometry/algorithms/detail/point_is_spike_or_equal.hpp b/boost/geometry/algorithms/detail/point_is_spike_or_equal.hpp index 9db1ef8e0c..399c8fbefc 100644 --- a/boost/geometry/algorithms/detail/point_is_spike_or_equal.hpp +++ b/boost/geometry/algorithms/detail/point_is_spike_or_equal.hpp @@ -1,9 +1,14 @@ // Boost.Geometry (aka GGL, Generic Geometry Library) -// Copyright (c) 2007-2013 Barend Gehrels, Amsterdam, the Netherlands. -// Copyright (c) 2008-2013 Bruno Lalande, Paris, France. -// Copyright (c) 2009-2013 Mateusz Loskot, London, UK. -// Copyright (c) 2013 Adam Wulkiewicz, Lodz, Poland. +// Copyright (c) 2007-2015 Barend Gehrels, Amsterdam, the Netherlands. +// Copyright (c) 2008-2015 Bruno Lalande, Paris, France. +// Copyright (c) 2009-2015 Mateusz Loskot, London, UK. +// Copyright (c) 2013-2015 Adam Wulkiewicz, Lodz, Poland. + +// This file was modified by Oracle on 2015. +// Modifications copyright (c) 2015 Oracle and/or its affiliates. + +// Contributed and/or modified by Menelaos Karavelas, on behalf of Oracle // Use, modification and distribution is subject to the Boost Software License, // Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at @@ -12,8 +17,6 @@ #ifndef BOOST_GEOMETRY_ALGORITHMS_DETAIL_POINT_IS_EQUAL_OR_SPIKE_HPP #define BOOST_GEOMETRY_ALGORITHMS_DETAIL_POINT_IS_EQUAL_OR_SPIKE_HPP -#include <boost/geometry/arithmetic/arithmetic.hpp> -#include <boost/geometry/algorithms/detail/convert_point_to_point.hpp> #include <boost/geometry/algorithms/detail/recalculate.hpp> #include <boost/geometry/policies/robustness/robust_point_type.hpp> #include <boost/geometry/strategies/side.hpp> @@ -28,6 +31,17 @@ namespace boost { namespace geometry namespace detail { +template <std::size_t Index, typename Point1, typename Point2> +inline int sign_of_difference(Point1 const& point1, Point2 const& point2) +{ + return + math::equals(geometry::get<Index>(point1), geometry::get<Index>(point2)) + ? + 0 + : + (geometry::get<Index>(point1) > geometry::get<Index>(point2) ? 1 : -1); +} + // Checks if a point ("last_point") causes a spike w.r.t. // the specified two other points (segment_a, segment_b) // @@ -35,7 +49,9 @@ namespace detail // 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) +// So specify last point first, then (a,b) +// The segment's orientation does matter: if lp is to the right of b +// no spike is reported template <typename Point1, typename Point2, typename Point3> static inline bool point_is_spike_or_equal(Point1 const& last_point, Point2 const& segment_a, @@ -46,29 +62,21 @@ static inline bool point_is_spike_or_equal(Point1 const& last_point, typename cs_tag<Point1>::type >::type side_strategy; - typedef Point1 vector_type; - int const side = side_strategy::apply(last_point, segment_a, segment_b); if (side == 0) { // Last point is collinear w.r.t previous segment. // Check if it is equal - vector_type diff1; - conversion::convert_point_to_point(last_point, diff1); - geometry::subtract_point(diff1, segment_b); - int const sgn_x1 = math::sign(geometry::get<0>(diff1)); - int const sgn_y1 = math::sign(geometry::get<1>(diff1)); + int const sgn_x1 = sign_of_difference<0>(last_point, segment_b); + int const sgn_y1 = sign_of_difference<1>(last_point, segment_b); if (sgn_x1 == 0 && sgn_y1 == 0) { return true; } // Check if it moves forward - vector_type diff2; - conversion::convert_point_to_point(segment_b, diff2); - geometry::subtract_point(diff2, segment_a); - int const sgn_x2 = math::sign(geometry::get<0>(diff2)); - int const sgn_y2 = math::sign(geometry::get<1>(diff2)); + int const sgn_x2 = sign_of_difference<0>(segment_b, segment_a); + int const sgn_y2 = sign_of_difference<1>(segment_b, segment_a); return sgn_x1 != sgn_x2 || sgn_y1 != sgn_y2; } |