This file is indexed.

/usr/include/CGAL/Arrangement_zone_2.h is in libcgal-dev 4.2-5ubuntu1.

This file is owned by root:root, with mode 0o644.

The actual contents of the file can be viewed below.

  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
// Copyright (c) 2006,2007,2009,2010,2011 Tel-Aviv University (Israel).
// All rights reserved.
//
// This file is part of CGAL (www.cgal.org).
// You can redistribute it and/or modify it under the terms of the GNU
// General Public License as published by the Free Software Foundation,
// either version 3 of the License, or (at your option) any later version.
//
// Licensees holding a valid commercial license may use this file in
// accordance with the commercial license agreement provided with the software.
//
// This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
// WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
//
// $URL$
// $Id$
// 
//
// Author(s)     : Ron Wein          <wein@post.tau.ac.il>
//                 Efi Fogel         <efif@post.tau.ac.il>
//                 (based on old version by Eyal Flato)

#ifndef CGAL_ARRANGEMENT_ZONE_2_H
#define CGAL_ARRANGEMENT_ZONE_2_H

/*! \file
 * Defintion of the Arrangement_zone_2 class.
 */

#include <boost/mpl/assert.hpp>
#include <CGAL/Arr_tags.h>
#include <CGAL/Arrangement_2/Arr_traits_adaptor_2.h>

#include <list>
#include <map>
#include <set>

namespace CGAL {

/*! \class
 * A class for computing the zone of a given $x$-monotone curve in a given
 * arrangement.
 * The arrangement parameter corresponds to the underlying arrangement, and
 * the zone-visitor parameter corresponds to a visitor class which is capable
 * of receiving notifications on the arrangment features the query curve
 * traverses. The visitor has to support the following functions:
 * - init(), for initializing the visitor with a given arrangement.
 * - found_subcurve(), called when a non-intersecting x-monotone curve is
 *                     computed and located in the arrangement.
 * - found_overlap(), called when an x-monotone curve overlaps an existing
 *                    halfedge in the arrangement.
 * Both the second and the third functions return pair<Halfedge_handle, bool>,
 * where the halfedge handle corresponds to the halfedge created or modified
 * by the visitor (if valid), and the Boolean value indicates whether we
 * should halt the zone-computation process.
 */
template <class Arrangement_, class ZoneVisitor_>
class Arrangement_zone_2
{
public:

  typedef Arrangement_                                   Arrangement_2;
  typedef typename Arrangement_2::Geometry_traits_2      Geometry_traits_2;
  typedef typename Arrangement_2::Topology_traits        Topology_traits;

protected:
  
  typedef Arr_traits_adaptor_2<Geometry_traits_2>        Traits_adaptor_2;

  typedef typename Traits_adaptor_2::Left_side_category   Left_side_category;
  typedef typename Traits_adaptor_2::Bottom_side_category Bottom_side_category;
  typedef typename Traits_adaptor_2::Top_side_category    Top_side_category;
  typedef typename Traits_adaptor_2::Right_side_category  Right_side_category;

  BOOST_MPL_ASSERT(
      (typename 
       Arr_sane_identified_tagging< Left_side_category, Bottom_side_category, 
       Top_side_category, Right_side_category >::result)
  );

public:
  
  typedef ZoneVisitor_                                   Visitor;

  typedef typename Arrangement_2::Vertex_handle          Vertex_handle;
  typedef typename Arrangement_2::Halfedge_handle        Halfedge_handle;
  typedef typename Arrangement_2::Face_handle            Face_handle;

  typedef std::pair<Halfedge_handle, bool>               Visitor_result;

  typedef typename Geometry_traits_2::Point_2            Point_2;
  typedef typename Geometry_traits_2::X_monotone_curve_2 X_monotone_curve_2;
  typedef typename Geometry_traits_2::Multiplicity       Multiplicity;

protected:

  typedef typename Arr_are_all_sides_oblivious_tag< 
                     Left_side_category, Bottom_side_category, 
                     Top_side_category, Right_side_category >::result
  Are_all_sides_oblivious_tag;
  
  typedef typename Arrangement_2::Vertex_const_handle    Vertex_const_handle;
  typedef typename Arrangement_2::Halfedge_const_handle  Halfedge_const_handle;
  typedef typename Arrangement_2::Face_const_handle      Face_const_handle;

  // Types used for caching intersection points:
  typedef std::pair<Point_2,Multiplicity>        Intersect_point_2;
  typedef std::list<CGAL::Object>                 Intersect_list;
  typedef std::map<const X_monotone_curve_2*,
                   Intersect_list>                Intersect_map;
  typedef typename Intersect_map::iterator        Intersect_map_iterator;

  typedef std::set<const X_monotone_curve_2*>     Curves_set;
  typedef typename Curves_set::iterator           Curves_set_iterator;

  // Data members:
  Arrangement_2&          arr;          // The associated arrangement.
  const Traits_adaptor_2 * m_geom_traits; // Its associated geometry traits.
  Arr_accessor<Arrangement_2> arr_access; // An accessor for the arrangement.
           
  Visitor                *visitor;      // The zone visitor.

  Intersect_map           inter_map;    // Stores all computed intersections.

  const Vertex_handle     invalid_v;    // An invalid vertex handle.
  const Halfedge_handle   invalid_he;   // An invalid halfedge handle.

  X_monotone_curve_2  cv;               // The current portion of the
                                        // inserted curve.
  CGAL::Object        obj;              // The location of the left endpoint.
  bool                has_left_pt;      // Is the left end of the curve
                                        // bounded.
  bool                left_on_boundary; // Is the left point on the boundary.
  Point_2             left_pt;          // Its current left endpoint.
  bool                has_right_pt;     // Is the right end of the curve
                                        // bounded.
  bool                right_on_boundary;// Is the right point on the boundary.
  Point_2             right_pt;         // Its right endpoint (if bounded).

  Vertex_handle       left_v;           // The arrangement vertex associated
                                        // with the current left_pt (if any).
  Halfedge_handle     left_he;          // If left_v is valid, left_he is the
                                        // predecessor for cv around this
                                        // vertex. Otherwise, if it is valid,
                                        // it is the halfedge that contains
                                        // the left endpoint it its interior.

  Vertex_handle       right_v;          // The arrangement vertex associated
                                        // with the current right_pt (if any).
  Halfedge_handle     right_he;         // If right_v is valid, left_he is the
                                        // predecessor for cv around this
                                        // vertex. Otherwise, if it is valid,
                                        // it is the halfedge that contains
                                        // the right endpoint it its interior.

  Point_2             intersect_p;      // The next intersection point.
  unsigned int        ip_mult;          // Its multiplicity
                                        // (0 in case of an overlap).
  bool                found_intersect;  // Have we found an intersection
                                        // (or an overlap).
  X_monotone_curve_2  overlap_cv;       // The currently discovered overlap.
  bool                found_overlap;    // Have we found an overlap.
  bool                found_iso_vert;   // Check if an isolated vertex induces
                                        // the next intersection.
  Vertex_handle       intersect_v;      // The vertex that intersects cv.
  Halfedge_handle     intersect_he;     // The halfedge that intersects cv
                                        // (or overlaps it).

  X_monotone_curve_2  sub_cv1;          // Auxiliary variable (for curve split).
  X_monotone_curve_2  sub_cv2;          // Auxiliary variable (for curve split).

public:

  /*!
   * Constructor.
   * \param _arr The arrangement for which we compute the zone.
   * \param _visitor A pointer to a zone-visitor object.
   */
  Arrangement_zone_2 (Arrangement_2& _arr, Visitor *_visitor) :
    arr (_arr),
    arr_access (_arr),
    visitor (_visitor),
    invalid_v (),
    invalid_he ()
  {
    m_geom_traits = static_cast<const Traits_adaptor_2*> (arr.geometry_traits());

    CGAL_assertion (visitor != NULL);

    // Initialize the visitor.
    visitor->init (&arr);
  }

  /*!
   * Initialize the zone-computation process with a given curve.
   * \param _cv The query curve.
   * \param pl A point-location object associated with the arrangement.
   */
  template <class PointLocation>
  void init (const X_monotone_curve_2& _cv, const PointLocation& pl)
  {
    // Set the curve and check whether its left end has boundary conditions.
    cv = _cv;

    const Arr_parameter_space  bx1 =
      m_geom_traits->parameter_space_in_x_2_object()(cv, ARR_MIN_END);
    const Arr_parameter_space  by1 =
      m_geom_traits->parameter_space_in_y_2_object()(cv, ARR_MIN_END);

    if (bx1 == ARR_INTERIOR && by1 == ARR_INTERIOR) {
      // The curve has a finite left endpoint with no boundary conditions:
      // locate it in the arrangement.
      has_left_pt = true;
      left_on_boundary = (bx1 != ARR_INTERIOR || by1 != ARR_INTERIOR);
      left_pt = m_geom_traits->construct_min_vertex_2_object() (cv);

      obj = pl.locate (left_pt);
    }
    else {
      // The left end of the curve has boundary conditions: use the topology
      // traits use the arrangement accessor to locate it.
      // Note that if the curve-end is unbounded, left_pt does not exist.
      // Note that if the curve-end is unbounded, left_pt does not exist.
      has_left_pt = m_geom_traits->is_closed_2_object()(cv, ARR_MIN_END);
      left_on_boundary = true;
      if (has_left_pt)
        left_pt = m_geom_traits->construct_min_vertex_2_object() (cv);
      obj = arr_access.locate_curve_end (cv, ARR_MIN_END, bx1, by1);
    }

    // Check the boundary conditions of th right curve end.
    if (m_geom_traits->is_closed_2_object()(cv, ARR_MAX_END)) {
      const Arr_parameter_space  bx2 =
        m_geom_traits->parameter_space_in_x_2_object()(cv, ARR_MAX_END);
      const Arr_parameter_space  by2 =
        m_geom_traits->parameter_space_in_y_2_object()(cv, ARR_MAX_END);

      // The right endpoint is valid.
      has_right_pt = true;
      right_pt = m_geom_traits->construct_max_vertex_2_object() (cv);
      right_on_boundary = (bx2 != ARR_INTERIOR) || (by2 != ARR_INTERIOR);
    }
    else {
      // The right end of the curve lies at infinity.
      has_right_pt = false;
      right_on_boundary = true;
    }

    return;
  }

  /*!
   * Initialize the zone-computation process with a given curve and an object
   * that wraps the location of the curve's left end.
   * \param _cv The query curve.
   * \param _obj An object that represents the location of the left end
   *             of the curve.
   */
  void init_with_hint (const X_monotone_curve_2& _cv, const Object& _obj);

  /*!
   * Compute the zone of the given curve and issue the apporpriate
   * notifications for the visitor.
   */
  void compute_zone ();

private:

  /*!
   * Find a face containing the query curve cv around the given vertex.
   * In case an overlap occurs, sets intersect_he to be the overlapping edge.
   * \param v The query vertex.
   * \param he Output: The predecessor of cv around the vertex.
   * \return (true) if cv overlaps with the curve associated with he;
   *         (false) if there is no overlap.
   */
  bool _find_prev_around_vertex (Vertex_handle v, Halfedge_handle& he);

  /*!
   * Direct the halfedge for the location of the given subcurve around a split
   * point that occurs in the interior of a given edge, when the subcurve lies
   * to the right of the split point.
   * In case of overlaps, it sets also found_overlap and intersect_he.
   * \param cv_ins The curve to be inserted, whose left endpoint coincides
   *               with the edge to be split.
   * \param cv_left_pt The left endpoint of cv_ins.
   * \param query_he The edge that intersects cv_ins.
   * \pre The left endpoint of cv_ins lies in the interior of the curve
   *      associated with query_he.
   * \return The halfedge whose incident face contains cv_ins
   *         (either query_he or its twin).
   */
  Halfedge_handle
  _direct_intersecting_edge_to_right(const X_monotone_curve_2& cv_ins,
                                     const Point_2& cv_left_pt,
                                     Halfedge_handle query_he);

  /*!
   * Direct the halfedge for the location of the given subcurve around a split
   * point that occurs in the interior of a given edge, when the subcurve lies
   * to the left of the split point.
   * \param cv_ins The curve to be inserted, whose right endpoint coincides
   *               with the edge to be split.
   * \param query_he The edge that intersects cv_ins.
   * \pre The right endpoint of cv_ins lies in the interior of the curve
   *      associated with query_he.
   * \return The halfedge whose incident face contains cv_ins
   *         (either query_he or its twin).
   */
  Halfedge_handle
  _direct_intersecting_edge_to_left(const X_monotone_curve_2& cv_ins,
                                    Halfedge_handle query_he);

  /*!
   * Get the next intersection of cv with the given halfedge.
   * \param he A handle to the halfedge.
   * \param skip_first_point Should we skip the first intersection point.
   * \param intersect_on_right_boundary Output: If an intersetion point is
   *                                            computed, marks whether this
   *                                            point coincides with the right
   *                                            curve-end, which lies on the
   *                                            surface boundary.
   * \return An object representing the next intersection: Intersect_point_2
   *         in case of a simple intersection point, X_monotone_curve_2 in
   *         case of an overlap, and an empty object if there is no
   *         intersection.
   */
  CGAL::Object _compute_next_intersection (Halfedge_handle he,
                                           bool skip_first_point,
                                           bool& intersect_on_right_boundary);

  /*!
   * Remove the next intersection of cv with the given halfedge from the map.
   * \param he A handle to the halfedge.
   * \pre The list of intersections with the curve of he has already been
   *      computed, and it is not empty.
   */
  void _remove_next_intersection (Halfedge_handle he);

  /*!
   * Check if the given point lies completely to the left of the given egde.
   * \param p The point.
   * \param he The halfedge.
   * \pre he is not a fictitious edge.
   * \return Whether p lies entirely to the left of the edge.
   */
  bool _is_to_left(const Point_2& p, Halfedge_handle he) const
  {
    return (_is_to_left_impl(p, he, Are_all_sides_oblivious_tag()));
  }

  bool _is_to_left_impl(const Point_2& p, Halfedge_handle he,
                        Arr_all_sides_oblivious_tag) const
  {
    return ((he->direction() == ARR_LEFT_TO_RIGHT &&
             m_geom_traits->compare_xy_2_object() 
             (p, he->source()->point()) == SMALLER) ||
            (he->direction() == ARR_RIGHT_TO_LEFT &&
             m_geom_traits->compare_xy_2_object() 
             (p, he->target()->point()) == SMALLER));
  }

  bool _is_to_left_impl(const Point_2& p, Halfedge_handle he,
                        Arr_not_all_sides_oblivious_tag) const;
  
  /*!
   * Check if the given point lies completely to the right of the given egde.
   * \param p The point.
   * \param he The halfedge.
   * \pre he is not a fictitious edge.
   * \return Whether p lies entirely to the right of the edge.
   */
  bool _is_to_right(const Point_2& p, Halfedge_handle he) const
  {
    return (_is_to_right_impl(p, he, Are_all_sides_oblivious_tag()));
  }

  bool _is_to_right_impl(const Point_2& p, Halfedge_handle he,
                         Arr_all_sides_oblivious_tag) const
  {
    return ((he->direction() == ARR_LEFT_TO_RIGHT &&
             m_geom_traits->compare_xy_2_object() 
             (p, he->target()->point()) == LARGER) ||
            (he->direction() == ARR_RIGHT_TO_LEFT &&
             m_geom_traits->compare_xy_2_object() 
             (p, he->source()->point()) == LARGER));
  }

  bool _is_to_right_impl(const Point_2& p, Halfedge_handle he,
                         Arr_not_all_sides_oblivious_tag) const;

  /*!
   * Compute the (lexicographically) leftmost intersection of the query
   * curve with the boundary of a given face in the arrangement.
   * The function computes sets intersect_p, intersect_he (or alternatively
   * overlap_cv and intersect_he) and set the flags found_intersect and
   * found_overlap accordingly.
   * \param face A handle to the face.
   * \param on_boundary Specifies whether the left endpoint of the curve lies
   *                    on the face boundary.
   */
  void _leftmost_intersection_with_face_boundary (Face_handle face,
                                                  bool on_boundary);

  /*!
   * Compute the zone of an x-monotone curve in a given arrangement face.
   * The left endpoint of the curve either lies in the face interior or on
   * the boundary of the face.
   * This function updates cv and its left endpoint and also sets left_v
   * and left_he for the remaining portion of the curve.
   * In case of overlaps, it sets also overlap_cv and intersect_he.
   * \param face The given face.
   * \param on_boundary Specifies whether the left endpoint of the curve lies
   *                    on the face boundary.
   * \pre If on_boundary is (true) then left_he must be valid; if it is (false)
   *      then both left_v anf left_he must be invalid.
   * \return (true) if we are done with the zone-computation process;
   *         (false) if we still have a remaining portion of cv to continue
   *         with.
   */
  bool _zone_in_face (Face_handle face,
		      bool on_boundary);

  /*!
   * Compute the zone of an overlapping subcurve overlap_cv of cv and the
   * curve currently associated with intersect_he.
   * This function updates cv and its left endpoint and also sets left_v
   * and left_he for the remaining portion of the curve.
   * \return (true) if we are done with the zone-computation process;
   *         (false) if we still have a remaining portion of cv to continue
   *         with.
   */
  bool _zone_in_overlap ();
};

} //namespace CGAL

// The function definitions can be found under:
#include <CGAL/Arrangement_2/Arrangement_zone_2_impl.h>

#endif