From f2a3351f7bcfaa3656d7e8ec6afca843bd7f857b Mon Sep 17 00:00:00 2001
From: Luke Simonson <simoluk@gmail.com>
Date: Mon, 25 Jul 2011 05:47:00 +0000
Subject: [PATCH] adding directed line segment concept

[SVN r73349]
---
 .../polygon/directed_line_segment_concept.hpp | 454 ++++++++++++++++++
 .../polygon/directed_line_segment_data.hpp    |  69 +++
 .../polygon/directed_line_segment_traits.hpp  |  42 ++
 include/boost/polygon/polygon.hpp             |   4 +
 4 files changed, 569 insertions(+)
 create mode 100644 include/boost/polygon/directed_line_segment_concept.hpp
 create mode 100644 include/boost/polygon/directed_line_segment_data.hpp
 create mode 100644 include/boost/polygon/directed_line_segment_traits.hpp
 mode change 100755 => 100644 include/boost/polygon/polygon.hpp

diff --git a/include/boost/polygon/directed_line_segment_concept.hpp b/include/boost/polygon/directed_line_segment_concept.hpp
new file mode 100644
index 0000000..436b928
--- /dev/null
+++ b/include/boost/polygon/directed_line_segment_concept.hpp
@@ -0,0 +1,454 @@
+/*
+  Copyright 2008 Intel Corporation
+ 
+  Use, modification and distribution are subject to the Boost Software License,
+  Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
+  http://www.boost.org/LICENSE_1_0.txt).
+*/
+#ifndef BOOST_POLYGON_DIRECTED_LINE_SEGMENT_CONCEPT_HPP
+#define BOOST_POLYGON_DIRECTED_LINE_SEGMENT_CONCEPT_HPP
+#include "isotropy.hpp"
+#include "directed_line_segment_data.hpp"
+#include "directed_line_segment_traits.hpp"
+#include "rectangle_concept.hpp"
+#include "detail/polygon_arbitrary_formation.hpp"
+
+namespace boost { namespace polygon{
+  struct directed_line_segment_concept {};
+ 
+  template <typename T>
+  struct is_directed_line_segment_concept { typedef gtl_no type; };
+  template <>
+  struct is_directed_line_segment_concept<directed_line_segment_concept> { typedef gtl_yes type; };
+
+  template <typename T>
+  struct is_mutable_directed_line_segment_concept { typedef gtl_no type; };
+  template <>
+  struct is_mutable_directed_line_segment_concept<directed_line_segment_concept> { typedef gtl_yes type; };
+
+  template <typename T, typename CT>
+  struct directed_line_segment_distance_type_by_concept { typedef void type; };
+  template <typename T>
+  struct directed_line_segment_distance_type_by_concept<T, gtl_yes> { 
+    typedef typename coordinate_traits<typename directed_line_segment_traits<T>::coordinate_type>::coordinate_distance type; };
+
+  template <typename T>
+  struct directed_line_segment_distance_type {
+      typedef typename directed_line_segment_distance_type_by_concept<
+            T, typename is_directed_line_segment_concept<typename geometry_concept<T>::type>::type>::type type;
+  };
+
+  template <typename T, typename CT>
+  struct directed_line_segment_point_type_by_concept { typedef void type; };
+  template <typename T>
+  struct directed_line_segment_point_type_by_concept<T, gtl_yes> { 
+    typedef typename directed_line_segment_traits<T>::point_type type; };
+
+  template <typename T>
+  struct directed_line_segment_point_type {
+      typedef typename directed_line_segment_point_type_by_concept<
+            T, typename is_directed_line_segment_concept<typename geometry_concept<T>::type>::type>::type type;
+  };
+
+  template <typename T, typename CT>
+  struct directed_line_segment_coordinate_type_by_concept { typedef void type; };
+  template <typename T>
+  struct directed_line_segment_coordinate_type_by_concept<T, gtl_yes> { 
+    typedef typename directed_line_segment_traits<T>::coordinate_type type; };
+
+  template <typename T>
+  struct directed_line_segment_coordinate_type {
+      typedef typename directed_line_segment_coordinate_type_by_concept<
+            T, typename is_directed_line_segment_concept<typename geometry_concept<T>::type>::type>::type type;
+  };
+
+  template <typename T>
+  typename directed_line_segment_point_type<T>::type
+  get(const T& segment, direction_1d dir,
+  typename enable_if<typename gtl_if<typename is_directed_line_segment_concept<typename geometry_concept<T>::type>::type>::type>::type * = 0
+  ) {
+    return directed_line_segment_traits<T>::get(segment, dir); 
+  }
+
+  template <typename T, typename point_type>
+  void 
+  set(T& segment, direction_1d dir, point_type value,
+  typename enable_if<typename is_mutable_directed_line_segment_concept<typename geometry_concept<T>::type>::type>::type * = 0
+  ) {
+    directed_line_segment_mutable_traits<T>::set(segment, dir, value); 
+  }
+  
+  template <typename T, typename T2, typename T3>
+  T
+  construct(T2 low_value, T3 high_value,
+            typename enable_if<typename is_mutable_directed_line_segment_concept<typename geometry_concept<T>::type>::type>::type * = 0
+  ) {
+    return directed_line_segment_mutable_traits<T>::construct(low_value, high_value); 
+  }
+  
+  template <typename T, typename T2>
+  T
+  copy_construct(const T2& segment,
+  typename enable_if< typename gtl_and<typename is_mutable_directed_line_segment_concept<typename geometry_concept<T>::type>::type,
+  typename is_directed_line_segment_concept<typename geometry_concept<T2>::type>::type>::type>::type * = 0
+  ) {
+    return construct<T>
+      (get(segment, LOW ),
+       get(segment, HIGH));
+  }
+
+  template <typename T1, typename T2>
+  T1 &
+  assign(T1& lvalue, const T2& rvalue,
+  typename enable_if< typename gtl_and< typename is_mutable_directed_line_segment_concept<typename geometry_concept<T1>::type>::type,
+  typename is_directed_line_segment_concept<typename geometry_concept<T2>::type>::type>::type>::type * = 0) {
+    lvalue = copy_construct<T1>(rvalue);
+    return lvalue;
+  }
+
+  template <typename T, typename T2>
+  bool 
+  equivalence(const T& segment1, const T2& segment2,
+  typename enable_if< typename gtl_and< typename is_directed_line_segment_concept<typename geometry_concept<T>::type>::type,
+  typename is_directed_line_segment_concept<typename geometry_concept<T2>::type>::type>::type>::type * = 0
+  ) {
+    return get(segment1, LOW) ==
+      get(segment2, LOW) &&
+      get(segment1, HIGH) ==
+      get(segment2, HIGH); 
+  }
+  
+  struct y_dls_on_above_or_below : gtl_yes {};
+
+  //-1 for below, 0 for on and 1 for above
+  template <typename segment_type>
+  typename enable_if< typename gtl_and< y_dls_on_above_or_below, typename is_directed_line_segment_concept<typename geometry_concept<segment_type>::type>::type >::type, bool>::type 
+  on_above_or_below(const segment_type& segment,
+                    typename directed_line_segment_traits<segment_type>::point_type value) {
+    typedef polygon_arbitrary_formation<typename directed_line_segment_traits<segment_type>::coordinate_type> paf;
+    typename paf::Point pt, l, h;
+    assign(pt, value);
+    assign(l, low(segment));
+    assign(h, high(segment));
+    return paf::on_above_or_below(pt, typename paf::half_edge(l, h));
+  }
+
+  struct y_dls_contains : gtl_yes {};
+
+  template <typename segment_type>
+  typename enable_if< typename gtl_and< y_dls_contains, typename is_directed_line_segment_concept<typename geometry_concept<segment_type>::type>::type >::type, bool>::type 
+  contains(const segment_type& segment,
+           typename directed_line_segment_traits<segment_type>::point_type value, 
+           bool consider_touch = true ) {
+    if(on_above_or_below(segment, value) == 0) {
+      rectangle_data<typename directed_line_segment_traits<segment_type>::coordinate_type> rect;
+      set_points(rect, low(segment), high(segment));
+      return contains(rect, value, consider_touch);
+    }
+    return false;
+  }
+  
+  template <typename segment_type, typename segment_type_2>
+  bool 
+  contains(const segment_type& segment,
+           const segment_type_2& value, bool consider_touch = true,
+           typename enable_if< typename gtl_and< typename is_directed_line_segment_concept<typename geometry_concept<segment_type>::type>::type,
+           typename is_directed_line_segment_concept<typename geometry_concept<segment_type_2>::type>::type>::type>::type * = 0
+           ) {
+    return contains(segment, get(value, LOW), consider_touch) &&
+      contains(segment, get(value, HIGH), consider_touch);
+  }
+  
+  // get the low point
+  template <typename segment_type>
+  typename directed_line_segment_point_type<segment_type>::type 
+  low(const segment_type& segment,
+  typename enable_if< typename is_directed_line_segment_concept<typename geometry_concept<segment_type>::type>::type>::type * = 0
+  ) { return get(segment, LOW); }
+
+  // get the high point
+  template <typename segment_type>
+  typename directed_line_segment_point_type<segment_type>::type 
+  high(const segment_type& segment,
+  typename enable_if< typename is_directed_line_segment_concept<typename geometry_concept<segment_type>::type>::type>::type * = 0
+  ) { return get(segment, HIGH); }
+
+  // get the center point
+  template <typename segment_type>
+  typename directed_line_segment_point_type<segment_type>::type
+  center(const segment_type& segment,
+  typename enable_if< typename is_directed_line_segment_concept<typename geometry_concept<segment_type>::type>::type>::type * = 0
+  ) { 
+    return construct<typename directed_line_segment_traits<segment_type>::point_type>((x(high(segment)) + x(low(segment)))/2,
+                                                                                      (y(high(segment)) + y(low(segment)))/2); 
+
+  }
+
+  struct y_dls_low : gtl_yes {};
+
+  // set the low point to v
+  template <typename segment_type>
+  typename enable_if<typename gtl_and<y_dls_low, typename is_mutable_directed_line_segment_concept<typename geometry_concept<segment_type>::type>::type>::type, void>::type 
+  low(segment_type& segment,
+      typename directed_line_segment_traits<segment_type>::point_type v) { set(segment, LOW, v); }
+  
+  struct y_dls_high : gtl_yes {};
+
+  // set the high coordinate to v
+  template <typename segment_type>
+  typename enable_if<typename gtl_and<y_dls_high, typename is_mutable_directed_line_segment_concept<typename geometry_concept<segment_type>::type>::type>::type, void>::type 
+  high(segment_type& segment,
+      typename directed_line_segment_traits<segment_type>::point_type v) { set(segment, HIGH, v); }
+  
+  template <typename segment_type>
+  typename directed_line_segment_distance_type<segment_type>::type 
+  length(const segment_type& segment,
+  typename enable_if< typename is_directed_line_segment_concept<typename geometry_concept<segment_type>::type>::type>::type * = 0
+  ) { return euclidean_distance(low(segment), high(segment)); }
+
+  struct y_dls_flip : gtl_yes {};
+
+  struct y_dls_scale_up : gtl_yes {};
+
+  // scale segment by factor
+  template <typename segment_type>
+  typename enable_if<typename gtl_and<y_dls_scale_up, typename is_mutable_directed_line_segment_concept<typename geometry_concept<segment_type>::type>::type>::type, segment_type>::type &
+  scale_up(segment_type& segment, 
+           typename coordinate_traits<typename directed_line_segment_traits<segment_type>::coordinate_type>::unsigned_area_type factor) {
+    typename directed_line_segment_point_type<segment_type>::type l = low(segment), h = high(segment);
+    low(segment, scale_up(l, factor));
+    high(segment, scale_up(h, factor));
+    return segment;
+  }
+
+  struct y_dls_scale_down : gtl_yes {};
+
+  template <typename segment_type>
+  typename enable_if<typename gtl_and<y_dls_scale_down, typename is_mutable_directed_line_segment_concept<typename geometry_concept<segment_type>::type>::type>::type, segment_type>::type &
+  scale_down(segment_type& segment, 
+             typename coordinate_traits<typename directed_line_segment_traits<segment_type>::coordinate_type>::unsigned_area_type factor) {
+    typename directed_line_segment_point_type<segment_type>::type l = low(segment), h = high(segment);
+    low(segment, scale_down(l, factor));
+    high(segment, scale_down(h, factor));
+    return segment;
+  }
+
+  struct y_dls_scale : gtl_yes {};
+
+  template <typename segment_type, typename scaling_type>
+  typename enable_if<typename gtl_and<y_dls_scale, typename is_mutable_directed_line_segment_concept<typename geometry_concept<segment_type>::type>::type>::type, segment_type>::type &
+  scale(segment_type& segment, scaling_type factor) {
+    typename directed_line_segment_point_type<segment_type>::type l = low(segment), h = high(segment);
+    low(segment, scale(l, factor));
+    high(segment, scale(h, factor));
+    return segment;
+  }
+
+
+  struct y_dls_transform : gtl_yes {};
+
+  template <typename segment_type, typename transform_type>
+  typename enable_if<typename gtl_and<y_dls_transform, typename is_mutable_directed_line_segment_concept<typename geometry_concept<segment_type>::type>::type>::type, segment_type>::type &
+  transform(segment_type& segment, const transform_type& val) {
+    typename directed_line_segment_point_type<segment_type>::type l = low(segment), h = high(segment);
+    low(segment, transform(l, val));
+    high(segment, transform(h, val));
+    return segment;
+  }  
+  // move segment by delta
+  template <typename segment_type>
+  segment_type&
+  move(segment_type& segment, orientation_2d orient,
+       typename directed_line_segment_coordinate_type<segment_type>::type displacement,
+       typename enable_if<typename is_mutable_directed_line_segment_concept<typename geometry_concept<segment_type>::type>::type>::type * = 0
+       ) {
+    typename directed_line_segment_point_type<segment_type>::type l = low(segment), h = high(segment);
+    low(segment, move(l, orient, displacement));
+    high(segment, move(h, orient, displacement));
+    return segment;
+  }
+  
+  struct y_dls_convolve : gtl_yes {};
+
+  // convolve this with b
+  template <typename segment_type>
+  typename enable_if<typename gtl_and<y_dls_convolve, typename is_mutable_directed_line_segment_concept<typename geometry_concept<segment_type>::type>::type>::type, segment_type>::type &
+  convolve(segment_type& segment,
+           const typename directed_line_segment_traits<segment_type>::point_type& b) {
+    typename directed_line_segment_point_type<segment_type>::type l = low(segment), h = high(segment);
+    low(segment, convolve(l, b));
+    high(segment, convolve(h, b));
+    return segment;
+  }
+
+  struct y_dls_deconvolve : gtl_yes {};
+
+  // deconvolve this with b
+  template <typename segment_type>
+  typename enable_if<typename gtl_and<y_dls_deconvolve, typename is_mutable_directed_line_segment_concept<typename geometry_concept<segment_type>::type>::type>::type, segment_type>::type &
+  deconvolve(segment_type& segment,
+             const typename directed_line_segment_traits<segment_type>::point_type& b) {
+    typename directed_line_segment_point_type<segment_type>::type l = low(segment), h = high(segment);
+    low(segment, deconvolve(l, b));
+    high(segment, deconvolve(h, b));
+    return segment;
+  }
+
+  struct y_dls_e_dist1 : gtl_yes {};
+
+  // distance from a point to a segment
+  template <typename segment_type>
+  typename enable_if< typename gtl_and<y_dls_e_dist1, typename is_directed_line_segment_concept<typename geometry_concept<segment_type>::type>::type>::type,
+      typename directed_line_segment_distance_type<segment_type>::type>::type
+  euclidean_distance(const segment_type& segment,
+                     typename directed_line_segment_traits<segment_type>::point_type position) {
+    typedef typename directed_line_segment_distance_type<segment_type>::type Unit;
+    Unit result1 = euclidean_distance(low(segment), high(segment));
+    Unit result2 = euclidean_distance(low(segment), position);
+    Unit result3 = euclidean_distance(high(segment), position);
+    if(result2 > result1) {
+      if(result3*result3 < result2*result2 - result1*result1)
+        return result3;
+    }
+    else if(result3 > result1) {
+      if(result2*result2 < result3*result3 - result1*result1)
+        return result2;
+    }
+    if(on_above_or_below(segment, position) == 0)
+      return 0.0; //I don't want to return non-zero distance if the predicate returns on the line
+    Unit x1 = x(low(segment));
+    Unit y1 = y(low(segment));
+    Unit x2 = x(high(segment));
+    Unit y2 = y(high(segment));
+    Unit X = x(position);
+    Unit Y = y(position);
+    Unit A = X - x1;
+    Unit B = Y - y1;
+    Unit C = x2 - x1;
+    Unit D = y2 - y1;
+    Unit denom = sqrt(C * C + D * D);
+    if(denom == 0.0)
+      return 0.0;
+    Unit result = (A * D - C * B) / denom;
+    if(result < 0.0)
+      result *= -1;
+    return result;
+  }
+
+  struct y_dls_e_dist2 : gtl_yes {};
+  
+  // distance between two segments
+  template <typename segment_type, typename segment_type_2>
+  typename enable_if< 
+    typename gtl_and_3<y_dls_e_dist2, typename is_directed_line_segment_concept<typename geometry_concept<segment_type>::type>::type,
+                       typename is_directed_line_segment_concept<typename geometry_concept<segment_type_2>::type>::type>::type,
+    typename directed_line_segment_distance_type<segment_type>::type>::type
+  euclidean_distance(const segment_type& segment,
+                     const segment_type_2& b) {
+    typename directed_line_segment_distance_type<segment_type>::type result1 = euclidean_distance(segment, low(b)),
+    result2 = euclidean_distance(segment, high(b));
+    if(result2 < result1) result1 = result2;
+    return result1;
+  }
+  
+  struct y_dls_e_intersects : gtl_yes {};
+
+  // check if Interval b intersects `this` Interval
+  template <typename segment_type, typename segment_type_2>
+  typename enable_if< typename gtl_and_3<y_dls_e_intersects, 
+                                         typename is_directed_line_segment_concept<typename geometry_concept<segment_type>::type>::type, 
+                                         typename is_directed_line_segment_concept<typename geometry_concept<segment_type_2>::type>::type
+  >::type, bool> ::type 
+  intersects(const segment_type& segment, const segment_type_2& b, bool consider_touch = true) {
+    if(consider_touch) {
+      if(low(segment) == low(b) || low(segment) == high(b) || high(segment) == low(b) || high(segment) == high(b))
+        return true;
+    }
+    typedef polygon_arbitrary_formation<typename directed_line_segment_traits<segment_type>::coordinate_type> paf;
+    typename paf::Point l, h, l2, h2;
+    assign(l, low(segment));
+    assign(h, high(segment));
+    assign(l2, low(b));
+    assign(h2, high(b));
+    return paf::intersects(typename paf::half_edge(l, h), typename paf::half_edge(l2, h2));
+  }
+
+  struct y_dls_e_bintersect : gtl_yes {};
+
+  // check if Interval b partially overlaps `this` Interval
+  template <typename segment_type, typename segment_type_2>
+  typename enable_if< 
+    typename gtl_and_3<y_dls_e_bintersect, typename is_directed_line_segment_concept<typename geometry_concept<segment_type>::type>::type,
+                       typename is_directed_line_segment_concept<typename geometry_concept<segment_type_2>::type>::type>::type,
+    bool>::type 
+  boundaries_intersect(const segment_type& segment, const segment_type_2& b, 
+                       bool consider_touch = true) {
+    return (contains(segment, low(b), consider_touch) || 
+            contains(segment, high(b), consider_touch)) &&
+      (contains(b, low(segment), consider_touch) || 
+       contains(b, high(segment), consider_touch));
+  }
+
+  struct y_dls_abuts1 : gtl_yes {};
+
+  // check if they are end to end
+  template <typename segment_type, typename segment_type_2>
+  typename enable_if< typename gtl_and_3<y_dls_abuts1, typename is_directed_line_segment_concept<typename geometry_concept<segment_type>::type>::type,
+                                         typename is_directed_line_segment_concept<typename geometry_concept<segment_type_2>::type>::type>::type,
+                       bool>::type 
+  abuts(const segment_type& segment, const segment_type_2& b, direction_1d dir) {
+    return dir.to_int() ? equivalence(low(b) , high(segment)) : equivalence(low(segment) , high(b));
+  }
+
+  struct y_dls_abuts2 : gtl_yes {};
+
+  // check if they are end to end
+  template <typename segment_type, typename segment_type_2>
+  typename enable_if< 
+    typename gtl_and_3<y_dls_abuts2, typename is_directed_line_segment_concept<typename geometry_concept<segment_type>::type>::type,
+                       typename is_directed_line_segment_concept<typename geometry_concept<segment_type_2>::type>::type>::type,
+    bool>::type 
+  abuts(const segment_type& segment, const segment_type_2& b) {
+    return abuts(segment, b, HIGH) || abuts(segment, b, LOW);
+  } 
+
+  struct y_dls_intersect : gtl_yes {};
+
+  // set point to the intersection of segment and b
+  template <typename point_type, typename segment_type, typename segment_type_2>
+    typename enable_if< typename gtl_and_4<y_dls_intersect, typename is_mutable_point_concept<typename geometry_concept<point_type>::type>::type,
+      typename is_directed_line_segment_concept<typename geometry_concept<segment_type>::type>::type,
+      typename is_directed_line_segment_concept<typename geometry_concept<segment_type_2>::type>::type>::type,
+                       bool>::type 
+  intersection(point_type& intersection, const segment_type& segment, const segment_type_2& b, 
+               bool projected = false, bool round_closest = false) {
+    typedef polygon_arbitrary_formation<typename directed_line_segment_traits<segment_type>::coordinate_type> paf;
+    typename paf::Point pt;
+    typename paf::Point l, h, l2, h2;
+    assign(l, low(segment));
+    assign(h, high(segment));
+    assign(l2, low(b));
+    assign(h2, high(b));
+    typename paf::half_edge he1(l, h), he2(l2, h2);
+    typename paf::compute_intersection_pack pack;
+    if(pack.compute_intersection(pt, he1, he2, projected, round_closest)) {
+      assign(intersection, pt);
+      return true;
+    }
+    return false;
+  }
+
+  template <class T>
+  template <class T2>
+  directed_line_segment_data<T>& directed_line_segment_data<T>::operator=(const T2& rvalue) {
+    assign(*this, rvalue);
+    return *this;
+  }
+
+  template <typename T>
+  struct geometry_concept<directed_line_segment_data<T> > {
+    typedef directed_line_segment_concept type;
+  };
+}
+}
+#endif
diff --git a/include/boost/polygon/directed_line_segment_data.hpp b/include/boost/polygon/directed_line_segment_data.hpp
new file mode 100644
index 0000000..670a6f5
--- /dev/null
+++ b/include/boost/polygon/directed_line_segment_data.hpp
@@ -0,0 +1,69 @@
+/*
+  Copyright 2008 Intel Corporation
+ 
+  Use, modification and distribution are subject to the Boost Software License,
+  Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
+  http://www.boost.org/LICENSE_1_0.txt).
+*/
+#ifndef BOOST_POLYGON_DIRECTED_LINE_SEGMENT_DATA_HPP
+#define BOOST_POLYGON_DIRECTED_LINE_SEGMENT_DATA_HPP
+#include "isotropy.hpp"
+#include "point_data.hpp"
+namespace boost { namespace polygon{
+  template <typename T>
+  class directed_line_segment_data {
+  public:
+    typedef T coordinate_type;
+    typedef point_data<T> point_type;
+    inline directed_line_segment_data()
+#ifndef BOOST_POLYGON_MSVC 
+      :points_() 
+#endif 
+    {} 
+    inline directed_line_segment_data(point_type low, point_type high)
+#ifndef BOOST_POLYGON_MSVC 
+      :points_() 
+#endif 
+    {
+      points_[LOW] = low; points_[HIGH] = high; 
+    }
+    inline directed_line_segment_data(const directed_line_segment_data& that)
+#ifndef BOOST_POLYGON_MSVC 
+      :points_() 
+#endif 
+    {
+      (*this) = that; 
+    }
+    inline directed_line_segment_data& operator=(const directed_line_segment_data& that) {
+      points_[0] = that.points_[0]; points_[1] = that.points_[1]; return *this; 
+    }
+    template <typename T2>
+    inline directed_line_segment_data& operator=(const T2& rvalue);
+    inline point_type get(direction_1d dir) const {
+      return points_[dir.to_int()]; 
+    }
+    inline point_type low() const { return points_[0]; }
+    inline point_type high() const { return points_[1]; }
+    inline bool operator==(const directed_line_segment_data& that) const {
+      return low() == that.low() && high() == that.high(); }
+    inline bool operator!=(const directed_line_segment_data& that) const {
+      return low() != that.low() || high() != that.high(); }
+    inline bool operator<(const directed_line_segment_data& that) const {
+      if(points_[0] < that.points_[0]) return true;
+      if(points_[0] > that.points_[0]) return false;
+      if(points_[1] < that.points_[1]) return true;
+      return false;
+    }
+    inline bool operator<=(const directed_line_segment_data& that) const { return !(that < *this); }
+    inline bool operator>(const directed_line_segment_data& that) const { return that < *this; }
+    inline bool operator>=(const directed_line_segment_data& that) const { return !((*this) < that); }
+  inline void set(direction_1d dir, point_type value) {
+    points_[dir.to_int()] = value; 
+  }
+private:
+  point_type points_[2]; 
+};
+
+}
+}
+#endif
diff --git a/include/boost/polygon/directed_line_segment_traits.hpp b/include/boost/polygon/directed_line_segment_traits.hpp
new file mode 100644
index 0000000..56fc077
--- /dev/null
+++ b/include/boost/polygon/directed_line_segment_traits.hpp
@@ -0,0 +1,42 @@
+/*
+  Copyright 2008 Intel Corporation
+ 
+  Use, modification and distribution are subject to the Boost Software License,
+  Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
+  http://www.boost.org/LICENSE_1_0.txt).
+*/
+#ifndef BOOST_POLYGON_DIRECTED_LINE_SEGMENT_TRAITS_HPP
+#define BOOST_POLYGON_DIRECTED_LINE_SEGMENT_TRAITS_HPP
+namespace boost { namespace polygon{
+  template <typename T>
+  struct directed_line_segment_traits {
+    typedef typename T::coordinate_type coordinate_type;
+    typedef typename T::point_type point_type;
+
+    static inline point_type get(const T& segment, direction_1d dir) {
+      return segment.get(dir); 
+    }
+  };
+
+  template <typename T>
+  struct directed_line_segment_mutable_traits {
+    template <typename Point1>
+    static inline void set(T& segment, direction_1d dir, const Point1& value) {
+      typename directed_line_segment_traits<T>::point_type p1;
+      assign(p1, value);
+      segment.set(dir, value); 
+    }
+    
+    template <typename Point1, typename Point2>
+    static inline T construct(const Point1& low_value, 
+                              const Point2& high_value) {
+      typename directed_line_segment_traits<T>::point_type p1, p2; 
+      assign(p1, low_value);
+      assign(p2, high_value);
+      return T(p1, p2); 
+    }
+  };
+}
+}
+#endif
+
diff --git a/include/boost/polygon/polygon.hpp b/include/boost/polygon/polygon.hpp
old mode 100755
new mode 100644
index 4c3e43a..d4048e7
--- a/include/boost/polygon/polygon.hpp
+++ b/include/boost/polygon/polygon.hpp
@@ -88,4 +88,8 @@
 
 #include "polygon_set_concept.hpp"
 
+#include "directed_line_segment_data.hpp"
+#include "directed_line_segment_traits.hpp"
+#include "directed_line_segment_concept.hpp"
+
 #endif