This file is indexed.

/usr/include/deal.II/grid/tria_boundary_lib.h is in libdeal.ii-dev 8.1.0-4.

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
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
// ---------------------------------------------------------------------
// $Id: tria_boundary_lib.h 30036 2013-07-18 16:55:32Z maier $
//
// Copyright (C) 1999 - 2013 by the deal.II authors
//
// This file is part of the deal.II library.
//
// The deal.II library is free software; you can use it, redistribute
// it, and/or modify it under the terms of the GNU Lesser General
// Public License as published by the Free Software Foundation; either
// version 2.1 of the License, or (at your option) any later version.
// The full text of the license can be found in the file LICENSE at
// the top level of the deal.II distribution.
//
// ---------------------------------------------------------------------

#ifndef __deal2__tria_boundary_lib_h
#define __deal2__tria_boundary_lib_h


#include <deal.II/base/config.h>
#include <deal.II/grid/tria_boundary.h>

DEAL_II_NAMESPACE_OPEN

/**
 * Boundary object for the hull of a cylinder.  In three dimensions,
 * points are projected on a circular tube along the <tt>x-</tt>,
 * <tt>y-</tt> or <tt>z</tt>-axis (when using the first constructor of
 * this class), or an arbitrarily oriented cylinder described by the
 * direction of its axis and a point located on the axis. The radius
 * of the tube can be given independently. Similar to
 * HyperBallBoundary, new points are projected by dividing the
 * straight line between the old two points and adjusting the radius
 * from the axis.
 *
 * This class was developed to be used in conjunction with the
 * @p cylinder function of GridGenerator. It should be used for
 * the hull of the cylinder only (boundary indicator 0). Its use is
 * discussed in detail in the results section of step-49.
 *
 * This class is derived from StraightBoundary rather than from
 * Boundary, which would seem natural, since this way we can use the
 * StraightBoundary::in_between() function.
 *
 * @ingroup boundary
 *
 * @author Guido Kanschat, 2001, Wolfgang Bangerth, 2007
 */
template <int dim, int spacedim = dim>
class CylinderBoundary : public StraightBoundary<dim,spacedim>
{
public:
  /**
   * Constructor. Using default values for the constructor arguments yields a
   * circular tube along the x-axis (<tt>axis=0</tt>). Choose <tt>axis=1</tt>
   * or <tt>axis=2</tt> for a tube along the y- or z-axis, respectively.
   */
  CylinderBoundary (const double radius = 1.0,
                    const unsigned int axis = 0);

  /**
   * Constructor. If constructed
   * with this constructor, the
   * boundary described is a
   * cylinder with an axis that
   * points in direction #direction
   * and goes through the given
   * #point_on_axis. The direction
   * may be arbitrarily scaled, and
   * the given point may be any
   * point on the axis.
   */
  CylinderBoundary (const double           radius,
                    const Point<spacedim> &direction,
                    const Point<spacedim> &point_on_axis);

  /**
   * Refer to the general documentation of
   * this class and the documentation of the
   * base class.
   */
  virtual Point<spacedim>
  get_new_point_on_line (const typename Triangulation<dim,spacedim>::line_iterator &line) const;

  /**
   * Refer to the general documentation of
   * this class and the documentation of the
   * base class.
   */
  virtual Point<spacedim>
  get_new_point_on_quad (const typename Triangulation<dim,spacedim>::quad_iterator &quad) const;

  /**
   * Refer to the general
   * documentation of this class
   * and the documentation of the
   * base class.
   *
   * Calls
   * @p get_intermediate_points_between_points.
   */
  virtual void
  get_intermediate_points_on_line (const typename Triangulation<dim,spacedim>::line_iterator &line,
                                   std::vector<Point<spacedim> > &points) const;

  /**
   * Refer to the general
   * documentation of this class
   * and the documentation of the
   * base class.
   *
   * Only implemented for <tt>dim=3</tt>
   * and for <tt>points.size()==1</tt>.
   */
  virtual void
  get_intermediate_points_on_quad (const typename Triangulation<dim,spacedim>::quad_iterator &quad,
                                   std::vector<Point<spacedim> > &points) const;

  /**
   * Compute the normals to the
   * boundary at the vertices of
   * the given face.
   *
   * Refer to the general
   * documentation of this class
   * and the documentation of the
   * base class.
   */
  virtual void
  get_normals_at_vertices (const typename Triangulation<dim,spacedim>::face_iterator &face,
                           typename Boundary<dim,spacedim>::FaceVertexNormals &face_vertex_normals) const;

  /**
   * Return the radius of the cylinder.
   */
  double get_radius () const;

  /**
   * Exception. Thrown by the
   * @p get_radius if the
   * @p compute_radius_automatically,
   * see below, flag is set true.
   */
  DeclException0 (ExcRadiusNotSet);


protected:
  /**
   * Radius of the cylinder.
   */
  const double radius;

  /**
   * The direction vector of the axis.
   */
  const Point<spacedim> direction;

  /**
   * An arbitrary point on the axis.
   */
  const Point<spacedim> point_on_axis;

private:

  /**
   * Called by
   * @p get_intermediate_points_on_line
   * and by
   * @p get_intermediate_points_on_quad.
   *
   * Refer to the general
   * documentation of
   * @p get_intermediate_points_on_line
   * in the documentation of the
   * base class.
   */
  void get_intermediate_points_between_points (const Point<spacedim> &p0, const Point<spacedim> &p1,
                                               std::vector<Point<spacedim> > &points) const;

  /**
   * Given a number for the axis,
   * return a vector that denotes
   * this direction.
   */
  static Point<spacedim> get_axis_vector (const unsigned int axis);
};



/**
 * Boundary object for the hull of a (truncated) cone with two
 * different radii at the two ends. If one radius is chosen to be 0
 * the object describes the boundary of a cone. In three dimensions,
 * points are projected on an arbitrarily oriented (truncated) cone
 * described by the two endpoints and the corresponding radii. Similar
 * to HyperBallBoundary, new points are projected by dividing the
 * straight line between the old two points and adjusting the radius
 * from the axis.
 *
 * This class is derived from StraightBoundary rather than from
 * Boundary, which would seem natural, since this way we can use the
 * StraightBoundary::in_between() function.
 *
 * As an example of use, consider the following code snippet:
 * @code
 *  Triangulation<dim> triangulation;
 *  GridGenerator::truncated_cone (triangulation);
 *  Point<dim> p1, p2;
 *  p1[0] = -1;
 *  p2[0] = 1;
 *  const ConeBoundary<dim> boundary (1, 0.5, p1, p2);
 *  triangulation.set_boundary (0, boundary);
 *  triangulation.refine_global (2);
 * @endcode
 * This will produce the following meshes after the two
 * refinements we perform, in 2d and 3d, respectively:
 *
 * @image html cone_2d.png
 * @image html cone_3d.png
 *
 * @author Markus B&uuml;rg, 2009
 */
template <int dim>
class ConeBoundary : public StraightBoundary<dim>
{
public:
  /**
   * Constructor. Here the boundary
   * object is constructed. The
   * points <tt>x_0</tt> and
   * <tt>x_1</tt> describe the
   * starting and ending points of
   * the axis of the (truncated)
   * cone. <tt>radius_0</tt>
   * denotes the radius
   * corresponding to <tt>x_0</tt>
   * and <tt>radius_1</tt> the one
   * corresponding to <tt>x_1</tt>.
   */
  ConeBoundary (const double radius_0,
                const double radius_1,
                const Point<dim> x_0,
                const Point<dim> x_1);

  /**
   * Return the radius of the
   * (truncated) cone at given point
   * <tt>x</tt> on the axis.
   */
  double get_radius (const Point<dim> x) const;

  /**
   * Refer to the general
   * documentation of this class
   * and the documentation of the
   * base class.
   */
  virtual
  Point<dim>
  get_new_point_on_line (const typename Triangulation<dim>::line_iterator &line) const;

  /**
   * Refer to the general
   * documentation of this class
   * and the documentation of the
   * base class.
   */
  virtual
  Point<dim>
  get_new_point_on_quad (const typename Triangulation<dim>::quad_iterator &quad) const;

  /**
   * Refer to the general
   * documentation of this class
   * and the documentation of the
   * base class.
   *
   * Calls @p
   * get_intermediate_points_between_points.
   */
  virtual
  void
  get_intermediate_points_on_line (const typename Triangulation<dim>::line_iterator &line,
                                   std::vector<Point<dim> > &points) const;

  /**
   * Refer to the general
   * documentation of this class
   * and the documentation of the
   * base class.
   *
   * Only implemented for
   * <tt>dim=3</tt> and for
   * <tt>points.size()==1</tt>.
   */
  virtual
  void
  get_intermediate_points_on_quad (const typename Triangulation<dim>::quad_iterator &quad,
                                   std::vector<Point<dim> > &points) const;

  /**
   * Compute the normals to the
   * boundary at the vertices of
   * the given face.
   *
   * Refer to the general
   * documentation of this class
   * and the documentation of the
   * base class.
   */
  virtual
  void
  get_normals_at_vertices (const typename Triangulation<dim>::face_iterator &face,
                           typename Boundary<dim>::FaceVertexNormals &face_vertex_normals) const;

protected:
  /**
   * First radius of the (truncated)
   * cone.
   */
  const double radius_0;

  /**
   * Second radius of the (truncated)
   * cone.
   */
  const double radius_1;

  /**
   * Starting point of the axis.
   */
  const Point<dim> x_0;

  /**
   * Ending point of the axis.
   */
  const Point<dim> x_1;

private:
  /**
   * Called by @p
   * get_intermediate_points_on_line
   * and by @p
   * get_intermediate_points_on_quad.
   *
   * Refer to the general
   * documentation of @p
   * get_intermediate_points_on_line
   * in the documentation of the
   * base class.
   */
  void
  get_intermediate_points_between_points (const Point<dim> &p0,
                                          const Point<dim> &p1,
                                          std::vector<Point<dim> > &points) const;
};



/**
 *   Specialization of Boundary<dim>, which places the new point on
 *   the boundary of a ball in arbitrary dimension. It works by projecting
 *   the point in the middle of the old points onto the ball. The middle is
 *   defined as the arithmetic mean of the points.
 *
 *   The center of the ball and its radius may be given upon construction of
 *   an object of this type. They default to the origin and a radius of 1.0.
 *
 *   This class is derived from StraightBoundary rather than from
 *   Boundary, which would seem natural, since this way we can use the
 *   StraightBoundary::in_between() function.
 *
 *   @ingroup boundary
 *
 *   @author Wolfgang Bangerth, 1998, Ralf Hartmann, 2001
 */
template <int dim, int spacedim=dim>
class HyperBallBoundary : public StraightBoundary<dim,spacedim>
{
public:
  /**
   * Constructor
   */
  HyperBallBoundary (const Point<spacedim> p      = Point<spacedim>(),
                     const double     radius = 1.0);

  /**
   * Refer to the general documentation of
   * this class and the documentation of the
   * base class.
   */
  virtual
  Point<spacedim>
  get_new_point_on_line (const typename Triangulation<dim,spacedim>::line_iterator &line) const;

  /**
   * Refer to the general documentation of
   * this class and the documentation of the
   * base class.
   */
  virtual
  Point<spacedim>
  get_new_point_on_quad (const typename Triangulation<dim,spacedim>::quad_iterator &quad) const;

  /**
   * Refer to the general
   * documentation of this class
   * and the documentation of the
   * base class.
   *
   * Calls
   * @p get_intermediate_points_between_points.
   */
  virtual
  void
  get_intermediate_points_on_line (const typename Triangulation<dim,spacedim>::line_iterator &line,
                                   std::vector<Point<spacedim> > &points) const;

  /**
   * Refer to the general
   * documentation of this class
   * and the documentation of the
   * base class.
   *
   * Only implemented for <tt>dim=3</tt>
   * and for <tt>points.size()==1</tt>.
   */
  virtual
  void
  get_intermediate_points_on_quad (const typename Triangulation<dim,spacedim>::quad_iterator &quad,
                                   std::vector<Point<spacedim> > &points) const;

  /**
   * Implementation of the function
   * declared in the base class.
   *
   * Refer to the general
   * documentation of this class
   * and the documentation of the
   * base class.
   */
  virtual
  Tensor<1,spacedim>
  normal_vector (const typename Triangulation<dim,spacedim>::face_iterator &face,
                 const Point<spacedim> &p) const;

  /**
   * Compute the normals to the
   * boundary at the vertices of
   * the given face.
   *
   * Refer to the general
   * documentation of this class
   * and the documentation of the
   * base class.
   */
  virtual
  void
  get_normals_at_vertices (const typename Triangulation<dim,spacedim>::face_iterator &face,
                           typename Boundary<dim,spacedim>::FaceVertexNormals &face_vertex_normals) const;

  /**
   * Return the center of the ball.
   */
  Point<spacedim>
  get_center () const;

  /**
   * Return the radius of the ball.
   */
  double
  get_radius () const;

  /**
   * Exception. Thrown by the
   * @p get_radius if the
   * @p compute_radius_automatically,
   * see below, flag is set true.
   */
  DeclException0 (ExcRadiusNotSet);


protected:

  /**
   * Center point of the hyperball.
   */
  const Point<spacedim> center;

  /**
   * Radius of the hyperball.
   */
  const double radius;

  /**
   * This flag is @p false for
   * this class and for all derived
   * classes that set the radius by
   * the constructor. For example
   * this flag is @p false for the
   * HalfHyperBallBoundary
   * class but it is @p true for
   * the HyperShellBoundary
   * class, for example.  The
   * latter class doesn't get its
   * radii by the constructor but
   * need to compute the radii
   * automatically each time one of
   * the virtual functions is
   * called.
   */
  bool compute_radius_automatically;

private:

  /**
   * Called by
   * @p get_intermediate_points_on_line
   * and by
   * @p get_intermediate_points_on_quad.
   *
   * Refer to the general
   * documentation of
   * @p get_intermediate_points_on_line
   * in the documentation of the
   * base class.
   */
  void get_intermediate_points_between_points (const Point<spacedim> &p0, const Point<spacedim> &p1,
                                               std::vector<Point<spacedim> > &points) const;
};



/**
 * Variant of HyperBallBoundary which denotes a half hyper ball
 * where the first coordinate is restricted to the range $x>=0$ (or
 * $x>=center(0)$). In two dimensions, this equals the right half
 * circle, in three space dimensions it is a half ball. This class
 * might be useful for computations with rotational symmetry, where
 * one dimension is the radius from the axis of rotation.
 *
 * @ingroup boundary
 *
 * @author Wolfgang Bangerth, 1999, 2001
 */
template <int dim>
class HalfHyperBallBoundary : public HyperBallBoundary<dim>
{
public:
  /**
   * Constructor
   */
  HalfHyperBallBoundary (const Point<dim> p      = Point<dim>(),
                         const double     radius = 1.0);

  /**
   * Check if on the line <tt>x==0</tt>,
   * otherwise pass to the base
   * class.
   */
  virtual Point<dim>
  get_new_point_on_line (const typename Triangulation<dim>::line_iterator &line) const;

  /**
   * Check if on the line <tt>x==0</tt>,
   * otherwise pass to the base
   * class.
   */
  virtual Point<dim>
  get_new_point_on_quad (const typename Triangulation<dim>::quad_iterator &quad) const;

  /**
   * Refer to the general
   * documentation of this class
   * and the documentation of the
   * base class.
   *
   * Calls
   * @p get_intermediate_points_between_points.
   */
  virtual void
  get_intermediate_points_on_line (const typename Triangulation<dim>::line_iterator &line,
                                   std::vector<Point<dim> > &points) const;

  /**
   * Refer to the general
   * documentation of this class
   * and the documentation of the
   * base class.
   *
   * Only implemented for <tt>dim=3</tt>
   * and for <tt>points.size()==1</tt>.
   */
  virtual void
  get_intermediate_points_on_quad (const typename Triangulation<dim>::quad_iterator &quad,
                                   std::vector<Point<dim> > &points) const;

  /**
   * Compute the normals to the
   * boundary at the vertices of
   * the given face.
   *
   * Refer to the general
   * documentation of this class
   * and the documentation of the
   * base class.
   */
  virtual void
  get_normals_at_vertices (const typename Triangulation<dim>::face_iterator &face,
                           typename Boundary<dim>::FaceVertexNormals &face_vertex_normals) const;
};



/**
 * Class describing the boundaries of a hyper shell. Only the center
 * of the two spheres needs to be given, the radii of inner and outer
 * sphere are computed automatically upon calling one of the virtual
 * functions.
 *
 * @ingroup boundary
 *
 * @author Wolfgang Bangerth, 1999
 */
template <int dim>
class HyperShellBoundary : public HyperBallBoundary<dim>
{
public:
  /**
   * Constructor. The center of the
   * spheres defaults to the
   * origin.
   *
   * Calls the constructor of its
   * base @p HyperBallBoundary
   * class with a dummy radius as
   * argument. This radius will be
   * ignored
   */
  HyperShellBoundary (const Point<dim> &center = Point<dim>());
};



/**
 * Variant of HyperShellBoundary which denotes a half hyper shell
 * where the first coordinate is restricted to the range $x>=0$ (or
 * $x>=center(0)$). In two dimensions, this equals the right half arc,
 * in three space dimensions it is a half shell. This class might be
 * useful for computations with rotational symmetry, where one
 * dimension is the radius from the axis of rotation.
 *
 * @ingroup boundary
 *
 * @author Wolfgang Bangerth, 2000, 2009
 */
template <int dim>
class HalfHyperShellBoundary : public HyperShellBoundary<dim>
{
public:
  /**
   * Constructor. The center of the
   * spheres defaults to the
   * origin.
   *
   * If the radii are not specified, the
   * class tries to infer them from the
   * location of points on the
   * boundary. This works in 2d, but not in
   * 3d. As a consequence, in 3d these
   * radii must be given.
   */
  HalfHyperShellBoundary (const Point<dim> &center = Point<dim>(),
                          const double inner_radius = -1,
                          const double outer_radius = -1);

  /**
   * Construct a new point on a line.
   */
  virtual Point<dim>
  get_new_point_on_line (const typename Triangulation<dim>::line_iterator &line) const;

  /**
   * Construct a new point on a quad.
   */
  virtual Point<dim>
  get_new_point_on_quad (const typename Triangulation<dim>::quad_iterator &quad) const;

  /**
   * Refer to the general
   * documentation of this class
   * and the documentation of the
   * base class.
   *
   * Calls
   * @p get_intermediate_points_between_points.
   */
  virtual void
  get_intermediate_points_on_line (const typename Triangulation<dim>::line_iterator &line,
                                   std::vector<Point<dim> > &points) const;

  /**
   * Refer to the general
   * documentation of this class
   * and the documentation of the
   * base class.
   *
   * Only implemented for <tt>dim=3</tt>
   * and for <tt>points.size()==1</tt>.
   */
  virtual void
  get_intermediate_points_on_quad (const typename Triangulation<dim>::quad_iterator &quad,
                                   std::vector<Point<dim> > &points) const;

  /**
   * Compute the normals to the
   * boundary at the vertices of
   * the given face.
   *
   * Refer to the general
   * documentation of this class
   * and the documentation of the
   * base class.
   */
  virtual void
  get_normals_at_vertices (const typename Triangulation<dim>::face_iterator &face,
                           typename Boundary<dim>::FaceVertexNormals &face_vertex_normals) const;

private:
  /**
   * Inner and outer radii of the shell.
   */
  const double inner_radius;
  const double outer_radius;
};


/**
 * Class describing the boundary of the torus. The axis of the torus is the
 * $y$-axis while the plane of the torus is the $x$-$z$ plane. A torus of this
 * kind can be generated by GridGenerator::torus.
 *
 * This class is only implemented for
 * <tt>dim=2</tt>,<tt>spacedim=3</tt>, that is, just the surface.
 */
template <int dim, int spacedim>
class TorusBoundary : public Boundary<dim,spacedim>
{
public:
  /**
   * Constructor.<tt>R</tt> has to be
   * greater than <tt>r</tt>.
   */
  TorusBoundary (const double R, const double r);

//Boundary Refinenment  Functions
  /**
   * Construct a new point on a line.
   */
  virtual Point<spacedim>
  get_new_point_on_line (const typename Triangulation<dim,spacedim>::line_iterator &line) const;

  /**
   * Construct a new point on a quad.
   */
  virtual Point<spacedim>
  get_new_point_on_quad (const typename Triangulation<dim,spacedim>::quad_iterator &quad) const;

  /**
   * Construct a new points on a line.
   */
  virtual void   get_intermediate_points_on_line (
    const typename Triangulation< dim, spacedim >::line_iterator   &line,
    std::vector< Point< spacedim > >         &points) const ;

  /**
   * Construct a new points on a quad.
   */
  virtual void  get_intermediate_points_on_quad (
    const typename Triangulation< dim, spacedim >::quad_iterator &quad,
    std::vector< Point< spacedim > >         &points ) const ;

  /**
   * Get the normal from cartesian
   * coordinates. This normal does not have
   * unit length.
   */
  virtual void get_normals_at_vertices (
    const typename Triangulation< dim, spacedim >::face_iterator &face,
    typename Boundary<dim,spacedim>::FaceVertexNormals &face_vertex_normals) const ;

private:
  //Handy functions
  /**
   * Function that corrects the value and
   * sign of angle, that is, given
   * <tt>angle=tan(abs(y/x))</tt>; if <tt>
   * (y > 0) && (x < 0) </tt> then
   * <tt>correct_angle = Pi - angle</tt>,
   * etc.
   */

  double           get_correct_angle(const double angle,const double x,const double y) const;

  /**
   * Get the cartesian coordinates of the
   * Torus, i.e., from <tt>(theta,phi)</tt>
   * to <tt>(x,y,z)</tt>.
   */
  Point<spacedim>  get_real_coord(const Point<dim> &surfP) const ;

  /**
   * Get the surface coordinates of the
   * Torus, i.e., from <tt>(x,y,z)</tt> to
   * <tt>(theta,phi)</tt>.
   */
  Point<dim>       get_surf_coord(const Point<spacedim> &p) const ;

  /**
   * Get the normal from surface
   * coordinates. This normal does not have
   * unit length.
   */
  Point<spacedim>  get_surf_norm_from_sp(const Point<dim> &surfP)      const ;

  /**
   * Get the normal from cartesian
   * coordinates. This normal does not have
   * unit length.
   */
  Point<spacedim>  get_surf_norm(const Point<spacedim> &p) const ;

  /**
   * Inner and outer radii of the shell.
   */
  const double R;
  const double r;
};



/* -------------- declaration of explicit specializations ------------- */

#ifndef DOXYGEN

template <>
Point<1>
HyperBallBoundary<1>::
get_new_point_on_quad (const Triangulation<1>::quad_iterator &) const;
template <>
void
HyperBallBoundary<1>::get_intermediate_points_on_line (
  const Triangulation<1>::line_iterator &,
  std::vector<Point<1> > &) const;
template <>
void
HyperBallBoundary<3>::get_intermediate_points_on_quad (
  const Triangulation<3>::quad_iterator &quad,
  std::vector<Point<3> > &points) const;
template <>
void
HyperBallBoundary<1>::
get_normals_at_vertices (const Triangulation<1,1>::face_iterator &,
                         Boundary<1,1>::FaceVertexNormals &) const;
template <>
Point<1>
HalfHyperBallBoundary<1>::
get_new_point_on_quad (const Triangulation<1>::quad_iterator &) const;
template <>
void
HalfHyperBallBoundary<1>::
get_intermediate_points_on_quad (const Triangulation<1>::quad_iterator &,
                                 std::vector<Point<1> > &) const;
template <>
void
HalfHyperBallBoundary<1>::
get_normals_at_vertices (const Triangulation<1,1>::face_iterator &,
                         Boundary<1,1>::FaceVertexNormals &) const;
template <>
Point<1>
HalfHyperShellBoundary<1>::
get_new_point_on_quad (const Triangulation<1>::quad_iterator &) const;
template <>
void
HalfHyperShellBoundary<1>::
get_intermediate_points_on_quad (const Triangulation<1>::quad_iterator &,
                                 std::vector<Point<1> > &) const;
template <>
void
HalfHyperShellBoundary<1>::
get_normals_at_vertices (const Triangulation<1,1>::face_iterator &,
                         Boundary<1,1>::FaceVertexNormals &) const;


#endif // DOXYGEN

DEAL_II_NAMESPACE_CLOSE

#endif