PolyConnectivity.cc 38.3 KB
Newer Older
Jan Möbius's avatar
Jan Möbius committed
1
2
3
/*===========================================================================*\
 *                                                                           *
 *                               OpenMesh                                    *
Jan Möbius's avatar
Jan Möbius committed
4
 *      Copyright (C) 2001-2012 by Computer Graphics Group, RWTH Aachen      *
Jan Möbius's avatar
Jan Möbius committed
5
6
 *                           www.openmesh.org                                *
 *                                                                           *
7
8
 *---------------------------------------------------------------------------* 
 *  This file is part of OpenMesh.                                           *
Jan Möbius's avatar
Jan Möbius committed
9
 *                                                                           *
10
11
12
13
14
 *  OpenMesh is free software: you can 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 3 of           *
 *  the License, or (at your option) any later version with the              *
 *  following exceptions:                                                    *
Jan Möbius's avatar
Jan Möbius committed
15
 *                                                                           *
16
17
18
19
20
21
22
 *  If other files instantiate templates or use macros                       *
 *  or inline functions from this file, or you compile this file and         *
 *  link it with other files to produce an executable, this file does        *
 *  not by itself cause the resulting executable to be covered by the        *
 *  GNU Lesser General Public License. This exception does not however       *
 *  invalidate any other reasons why the executable file might be            *
 *  covered by the GNU Lesser General Public License.                        *
Jan Möbius's avatar
Jan Möbius committed
23
 *                                                                           *
24
25
26
27
 *  OpenMesh is distributed in the hope that it will be useful,              *
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of           *
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the            *
 *  GNU Lesser General Public License for more details.                      *
Jan Möbius's avatar
Jan Möbius committed
28
 *                                                                           *
29
30
31
32
33
34
35
36
37
38
 *  You should have received a copy of the GNU LesserGeneral Public          *
 *  License along with OpenMesh.  If not,                                    *
 *  see <http://www.gnu.org/licenses/>.                                      *
 *                                                                           *
\*===========================================================================*/ 

/*===========================================================================*\
 *                                                                           *             
 *   $Revision$                                                         *
 *   $Date$                   *
Jan Möbius's avatar
Jan Möbius committed
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
 *                                                                           *
\*===========================================================================*/

//== IMPLEMENTATION ==========================================================
#include <OpenMesh/Core/Mesh/PolyConnectivity.hh>
#include <set>

namespace OpenMesh {

const PolyConnectivity::VertexHandle    PolyConnectivity::InvalidVertexHandle;
const PolyConnectivity::HalfedgeHandle  PolyConnectivity::InvalidHalfedgeHandle;
const PolyConnectivity::EdgeHandle      PolyConnectivity::InvalidEdgeHandle;
const PolyConnectivity::FaceHandle      PolyConnectivity::InvalidFaceHandle;

//-----------------------------------------------------------------------------
54

Jan Möbius's avatar
Jan Möbius committed
55
56
57
58
59
PolyConnectivity::HalfedgeHandle
PolyConnectivity::find_halfedge(VertexHandle _start_vh, VertexHandle _end_vh ) const
{
  assert(_start_vh.is_valid() && _end_vh.is_valid());

60
61
62
  for (ConstVertexOHalfedgeIter voh_it = cvoh_iter(_start_vh); voh_it.is_valid(); ++voh_it)
    if (to_vertex_handle(*voh_it) == _end_vh)
      return *voh_it;
Jan Möbius's avatar
Jan Möbius committed
63
64
65
66
67
68
69

  return InvalidHalfedgeHandle;
}


bool PolyConnectivity::is_boundary(FaceHandle _fh, bool _check_vertex) const
{
Jan Möbius's avatar
Jan Möbius committed
70
71
  for (ConstFaceEdgeIter cfeit = cfe_iter( _fh ); cfeit.is_valid(); ++cfeit)
      if (is_boundary( *cfeit ) )
Jan Möbius's avatar
Jan Möbius committed
72
73
74
75
        return true;

  if (_check_vertex)
  {
Jan Möbius's avatar
Jan Möbius committed
76
77
      for (ConstFaceVertexIter cfvit = cfv_iter( _fh ); cfvit.is_valid(); ++cfvit)
        if (is_boundary( *cfvit ) )
Jan Möbius's avatar
Jan Möbius committed
78
79
80
81
82
83
84
85
86
87
88
89
90
91
            return true;
  }
  return false;
}

bool PolyConnectivity::is_manifold(VertexHandle _vh) const
{
  /* The vertex is non-manifold if more than one gap exists, i.e.
    more than one outgoing boundary halfedge. If (at least) one
    boundary halfedge exists, the vertex' halfedge must be a
    boundary halfedge. If iterating around the vertex finds another
    boundary halfedge, the vertex is non-manifold. */

  ConstVertexOHalfedgeIter vh_it(*this, _vh);
Jan Möbius's avatar
Jan Möbius committed
92
93
94
  if (vh_it.is_valid())
    for (++vh_it; vh_it.is_valid(); ++vh_it)
        if (is_boundary(*vh_it))
Jan Möbius's avatar
Jan Möbius committed
95
96
97
98
99
100
101
          return false;
  return true;
}

//-----------------------------------------------------------------------------
void PolyConnectivity::adjust_outgoing_halfedge(VertexHandle _vh)
{
Jan Möbius's avatar
Jan Möbius committed
102
  for (ConstVertexOHalfedgeIter vh_it=cvoh_iter(_vh); vh_it.is_valid(); ++vh_it)
Jan Möbius's avatar
Jan Möbius committed
103
  {
Jan Möbius's avatar
Jan Möbius committed
104
    if (is_boundary(*vh_it))
Jan Möbius's avatar
Jan Möbius committed
105
    {
Jan Möbius's avatar
Jan Möbius committed
106
      set_halfedge_handle(_vh, *vh_it);
Jan Möbius's avatar
Jan Möbius committed
107
108
109
110
111
112
113
114
      break;
    }
  }
}

//-----------------------------------------------------------------------------

PolyConnectivity::FaceHandle
Jan Möbius's avatar
Jan Möbius committed
115
PolyConnectivity::add_face(const VertexHandle* _vertex_handles, size_t _vhs_size)
Jan Möbius's avatar
Jan Möbius committed
116
117
{
  VertexHandle                   vh;
Jan Möbius's avatar
Jan Möbius committed
118
  size_t                         i, ii, n(_vhs_size), id;
Jan Möbius's avatar
Jan Möbius committed
119
120
121
122
123
124
  HalfedgeHandle                 inner_next, inner_prev,
                                 outer_next, outer_prev,
                                 boundary_next, boundary_prev,
                                 patch_start, patch_end;


125
126
127
128
129
130
131
132
  // Check sufficient working storage available
  if (edgeData_.size() < n)
  {
    edgeData_.resize(n);
    next_cache_.resize(6*n);
  }
  next_cache_count_ = 0;

Jan Möbius's avatar
Jan Möbius committed
133
134
135
136
137
138
139
140
141
142
143
144
  // don't allow degenerated faces
  assert (n > 2);

  // test for topological errors
  for (i=0, ii=1; i<n; ++i, ++ii, ii%=n)
  {
    if ( !is_boundary(_vertex_handles[i]) )
    {
      omerr() << "PolyMeshT::add_face: complex vertex\n";
      return InvalidFaceHandle;
    }

145
146
147
148
149
    // Initialise edge attributes
    edgeData_[i].halfedge_handle = find_halfedge(_vertex_handles[i],
                                                 _vertex_handles[ii]);
    edgeData_[i].is_new = !edgeData_[i].halfedge_handle.is_valid();
    edgeData_[i].needs_adjust = false;
Jan Möbius's avatar
Jan Möbius committed
150

151
    if (!edgeData_[i].is_new && !is_boundary(edgeData_[i].halfedge_handle))
Jan Möbius's avatar
Jan Möbius committed
152
153
154
155
156
157
158
159
160
    {
      omerr() << "PolyMeshT::add_face: complex edge\n";
      return InvalidFaceHandle;
    }
  }

  // re-link patches if necessary
  for (i=0, ii=1; i<n; ++i, ++ii, ii%=n)
  {
161
    if (!edgeData_[i].is_new && !edgeData_[ii].is_new)
Jan Möbius's avatar
Jan Möbius committed
162
    {
163
164
165
      inner_prev = edgeData_[i].halfedge_handle;
      inner_next = edgeData_[ii].halfedge_handle;

Jan Möbius's avatar
Jan Möbius committed
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

      if (next_halfedge_handle(inner_prev) != inner_next)
      {
        // here comes the ugly part... we have to relink a whole patch

        // search a free gap
        // free gap will be between boundary_prev and boundary_next
        outer_prev = opposite_halfedge_handle(inner_next);
        outer_next = opposite_halfedge_handle(inner_prev);
        boundary_prev = outer_prev;
        do
          boundary_prev =
            opposite_halfedge_handle(next_halfedge_handle(boundary_prev));
        while (!is_boundary(boundary_prev) || boundary_prev==inner_prev);
        boundary_next = next_halfedge_handle(boundary_prev);
        assert(is_boundary(boundary_prev));
        assert(is_boundary(boundary_next));
        // ok ?
        if (boundary_next == inner_next)
        {
          omerr() << "PolyMeshT::add_face: patch re-linking failed\n";
          return InvalidFaceHandle;
        }

        // other halfedges' handles
        patch_start = next_halfedge_handle(inner_prev);
        patch_end   = prev_halfedge_handle(inner_next);

194
195
196
197
198
199
200
        assert(boundary_prev.is_valid());
        assert(patch_start.is_valid());
        assert(patch_end.is_valid());
        assert(boundary_next.is_valid());
        assert(inner_prev.is_valid());
        assert(inner_next.is_valid());

Jan Möbius's avatar
Jan Möbius committed
201
        // relink
202
203
204
        next_cache_[next_cache_count_++] = std::make_pair(boundary_prev, patch_start);
        next_cache_[next_cache_count_++] = std::make_pair(patch_end, boundary_next);
        next_cache_[next_cache_count_++] = std::make_pair(inner_prev, inner_next);
Jan Möbius's avatar
Jan Möbius committed
205
206
207
208
209
210
      }
    }
  }

  // create missing edges
  for (i=0, ii=1; i<n; ++i, ++ii, ii%=n)
211
212
    if (edgeData_[i].is_new)
      edgeData_[i].halfedge_handle = new_edge(_vertex_handles[i], _vertex_handles[ii]);
Jan Möbius's avatar
Jan Möbius committed
213
214
215

  // create the face
  FaceHandle fh(new_face());
216
  set_halfedge_handle(fh, edgeData_[n-1].halfedge_handle);
Jan Möbius's avatar
Jan Möbius committed
217
218
219
220
221

  // setup halfedges
  for (i=0, ii=1; i<n; ++i, ++ii, ii%=n)
  {
    vh         = _vertex_handles[ii];
222
223
224

    inner_prev = edgeData_[i].halfedge_handle;
    inner_next = edgeData_[ii].halfedge_handle;
225
226
    assert(inner_prev.is_valid());
    assert(inner_next.is_valid());
Jan Möbius's avatar
Jan Möbius committed
227
228

    id = 0;
229
230
231
    if (edgeData_[i].is_new)  id |= 1;
    if (edgeData_[ii].is_new) id |= 2;

Jan Möbius's avatar
Jan Möbius committed
232
233
234
235
236

    if (id)
    {
      outer_prev = opposite_halfedge_handle(inner_next);
      outer_next = opposite_halfedge_handle(inner_prev);
237
238
      assert(outer_prev.is_valid());
      assert(outer_next.is_valid());
Jan Möbius's avatar
Jan Möbius committed
239
240
241
242
243
244

      // set outer links
      switch (id)
      {
        case 1: // prev is new, next is old
          boundary_prev = prev_halfedge_handle(inner_next);
245
          assert(boundary_prev.is_valid());
246
          next_cache_[next_cache_count_++] = std::make_pair(boundary_prev, outer_next);
Jan Möbius's avatar
Jan Möbius committed
247
248
249
250
251
          set_halfedge_handle(vh, outer_next);
          break;

        case 2: // next is new, prev is old
          boundary_next = next_halfedge_handle(inner_prev);
252
          assert(boundary_next.is_valid());
253
          next_cache_[next_cache_count_++] = std::make_pair(outer_prev, boundary_next);
Jan Möbius's avatar
Jan Möbius committed
254
255
256
257
258
259
260
          set_halfedge_handle(vh, boundary_next);
          break;

        case 3: // both are new
          if (!halfedge_handle(vh).is_valid())
          {
            set_halfedge_handle(vh, outer_next);
261
            next_cache_[next_cache_count_++] = std::make_pair(outer_prev, outer_next);
Jan Möbius's avatar
Jan Möbius committed
262
263
264
265
266
          }
          else
          {
            boundary_next = halfedge_handle(vh);
            boundary_prev = prev_halfedge_handle(boundary_next);
267
268
            assert(boundary_prev.is_valid());
            assert(boundary_next.is_valid());
269
270
            next_cache_[next_cache_count_++] = std::make_pair(boundary_prev, outer_next);
            next_cache_[next_cache_count_++] = std::make_pair(outer_prev, boundary_next);
Jan Möbius's avatar
Jan Möbius committed
271
272
273
274
275
          }
          break;
      }

      // set inner link
276
      next_cache_[next_cache_count_++] = std::make_pair(inner_prev, inner_next);
Jan Möbius's avatar
Jan Möbius committed
277
    }
278
279
    else edgeData_[ii].needs_adjust = (halfedge_handle(vh) == inner_next);

Jan Möbius's avatar
Jan Möbius committed
280
281

    // set face handle
282
    set_face_handle(edgeData_[i].halfedge_handle, fh);
Jan Möbius's avatar
Jan Möbius committed
283
284
285
  }

  // process next halfedge cache
286
287
288
  for (i = 0; i < next_cache_count_; ++i)
    set_next_halfedge_handle(next_cache_[i].first, next_cache_[i].second);

Jan Möbius's avatar
Jan Möbius committed
289
290
291

  // adjust vertices' halfedge handle
  for (i=0; i<n; ++i)
292
    if (edgeData_[i].needs_adjust)
Jan Möbius's avatar
Jan Möbius committed
293
294
295
296
297
      adjust_outgoing_halfedge(_vertex_handles[i]);

  return fh;
}

298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
//-----------------------------------------------------------------------------

FaceHandle PolyConnectivity::add_face(VertexHandle _vh0, VertexHandle _vh1, VertexHandle _vh2, VertexHandle _vh3)
{
  VertexHandle vhs[4] = { _vh0, _vh1, _vh2, _vh3 };
  return add_face(vhs, 4);
}

//-----------------------------------------------------------------------------

FaceHandle PolyConnectivity::add_face(VertexHandle _vh0, VertexHandle _vh1, VertexHandle _vh2)
{
  VertexHandle vhs[3] = { _vh0, _vh1, _vh2 };
  return add_face(vhs, 3);
}

//-----------------------------------------------------------------------------

FaceHandle PolyConnectivity::add_face(const std::vector<VertexHandle>& _vhandles)
{ return add_face(&_vhandles.front(), _vhandles.size()); }
318
319
320
321
322


//-----------------------------------------------------------------------------
bool PolyConnectivity::is_collapse_ok(HalfedgeHandle v0v1)
{
323
324
325
326
327
328
  //is edge already deleteed?
  if (status(edge_handle(v0v1)).deleted())
  {
    return false;
  }

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
  HalfedgeHandle v1v0(opposite_halfedge_handle(v0v1));
  VertexHandle v0(to_vertex_handle(v1v0));
  VertexHandle v1(to_vertex_handle(v0v1));  

  bool v0v1_triangle = false;
  bool v1v0_triangle = false;
  
  if (!is_boundary(v0v1))
    v0v1_triangle = valence(face_handle(v0v1)) == 3;
  
  if (!is_boundary(v1v0))
    v1v0_triangle = valence(face_handle(v1v0)) == 3;

  //in a quadmesh we dont have the "next" or "previous" vhandle, so we need to look at previous and next on both sides
  VertexHandle v_01_p = from_vertex_handle(prev_halfedge_handle(v0v1));
  VertexHandle v_01_n = to_vertex_handle(next_halfedge_handle(v0v1));  

  VertexHandle v_10_p = from_vertex_handle(prev_halfedge_handle(v1v0));
  VertexHandle v_10_n = to_vertex_handle(next_halfedge_handle(v1v0));

  //are the vertices already deleted ?
  if (status(v0).deleted() || status(v1).deleted())
  {
    return false;
  }

  //the edges v1-vl and vl-v0 must not be both boundary edges
  //this test makes only sense in a polymesh if the side face is a triangle
  if (!is_boundary(v0v1))
  {
    if (v0v1_triangle)
    {
      VertexHandle vl = to_vertex_handle(next_halfedge_handle(v0v1));

      HalfedgeHandle h1 = next_halfedge_handle(v0v1);
      HalfedgeHandle h2 = next_halfedge_handle(h1);
      if (is_boundary(opposite_halfedge_handle(h1)) && is_boundary(opposite_halfedge_handle(h2)))
	return false;
    }
  }

  //the edges v0-vr and vr-v1 must not be both boundary edges
  //this test makes only sense in a polymesh if the side face is a triangle
  if (!is_boundary(v1v0))
  {
    if (v1v0_triangle)
    {
      VertexHandle vr = to_vertex_handle(next_halfedge_handle(v1v0));

      HalfedgeHandle h1 = next_halfedge_handle(v1v0);
      HalfedgeHandle h2 = next_halfedge_handle(h1);
      if (is_boundary(opposite_halfedge_handle(h1)) && is_boundary(opposite_halfedge_handle(h2)))
	return false;
    }
  }

  // edge between two boundary vertices should be a boundary edge
  if ( is_boundary(v0) && is_boundary(v1) && !is_boundary(v0v1) && !is_boundary(v1v0))
    return false;
  
  VertexVertexIter vv_it;
  // test intersection of the one-rings of v0 and v1
Jan Möbius's avatar
Jan Möbius committed
391
  for (vv_it = vv_iter(v0); vv_it.is_valid(); ++vv_it)
392
  {
Jan Möbius's avatar
Jan Möbius committed
393
    status(*vv_it).set_tagged(false);
394
395
  }

Jan Möbius's avatar
Jan Möbius committed
396
  for (vv_it = vv_iter(v1); vv_it.is_valid(); ++vv_it)
397
  {
Jan Möbius's avatar
Jan Möbius committed
398
    status(*vv_it).set_tagged(true);
399
400
  }

Jan Möbius's avatar
Jan Möbius committed
401
  for (vv_it = vv_iter(v0); vv_it.is_valid(); ++vv_it)
402
  {
Jan Möbius's avatar
Jan Möbius committed
403
    if (status(*vv_it).tagged() &&
404
405
      !(*vv_it == v_01_n && v0v1_triangle) &&
      !(*vv_it == v_10_n && v1v0_triangle)
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
      )
    {
      return false;
    }
  }
  
  //test for a face on the backside/other side that might degenerate
  if (v0v1_triangle)
  {
    HalfedgeHandle one, two;
    one = next_halfedge_handle(v0v1);
    two = next_halfedge_handle(one);
    
    one = opposite_halfedge_handle(one);
    two = opposite_halfedge_handle(two);
    
    if (face_handle(one) == face_handle(two) && valence(face_handle(one)) != 3)
    {
      return false;
    }
  }
  
  if (v1v0_triangle)
  {
    HalfedgeHandle one, two;
    one = next_halfedge_handle(v1v0);
    two = next_halfedge_handle(one);
    
    one = opposite_halfedge_handle(one);
    two = opposite_halfedge_handle(two);
    
    if (face_handle(one) == face_handle(two) && valence(face_handle(one)) != 3)
    {
      return false;
    }
  }

Jan Möbius's avatar
Jan Möbius committed
443
  if (status(*vv_it).tagged() && v_01_n == v_10_n && v0v1_triangle && v1v0_triangle)
444
445
446
447
448
449
450
451
  {
    return false;
  }

  // passed all tests
  return true;
}

Jan Möbius's avatar
Jan Möbius committed
452
453
454
455
456
457
458
//-----------------------------------------------------------------------------

void PolyConnectivity::delete_vertex(VertexHandle _vh, bool _delete_isolated_vertices)
{
  // store incident faces
  std::vector<FaceHandle> face_handles;
  face_handles.reserve(8);
Jan Möbius's avatar
Jan Möbius committed
459
460
  for (VFIter vf_it(vf_iter(_vh)); vf_it.is_valid(); ++vf_it)
    face_handles.push_back(*vf_it);
Jan Möbius's avatar
Jan Möbius committed
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481


  // delete collected faces
  std::vector<FaceHandle>::iterator fh_it(face_handles.begin()),
                                    fh_end(face_handles.end());

  for (; fh_it!=fh_end; ++fh_it)
    delete_face(*fh_it, _delete_isolated_vertices);

  status(_vh).set_deleted(true);
}

//-----------------------------------------------------------------------------

void PolyConnectivity::delete_edge(EdgeHandle _eh, bool _delete_isolated_vertices)
{
  FaceHandle fh0(face_handle(halfedge_handle(_eh, 0)));
  FaceHandle fh1(face_handle(halfedge_handle(_eh, 1)));

  if (fh0.is_valid())  delete_face(fh0, _delete_isolated_vertices);
  if (fh1.is_valid())  delete_face(fh1, _delete_isolated_vertices);
482

483
484
485
486
487
488
489
490
491
492
493
494
495
496
  // If there is no face, we delete the edge
  // here
  if ( ! fh0.is_valid() && !fh1.is_valid()) {
    // mark edge deleted if the mesh has a edge status
    if ( has_edge_status() )
      status(_eh).set_deleted(true);

    // mark corresponding halfedges as deleted
    // As the deleted edge is boundary,
    // all corresponding halfedges will also be deleted.
    if ( has_halfedge_status() ) {
      status(halfedge_handle(_eh, 0)).set_deleted(true);
      status(halfedge_handle(_eh, 1)).set_deleted(true);
    }
497
  }
Jan Möbius's avatar
Jan Möbius committed
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
}

//-----------------------------------------------------------------------------

void PolyConnectivity::delete_face(FaceHandle _fh, bool _delete_isolated_vertices)
{
  assert(_fh.is_valid() && !status(_fh).deleted());

  // mark face deleted
  status(_fh).set_deleted(true);


  // this vector will hold all boundary edges of face _fh
  // these edges will be deleted
  std::vector<EdgeHandle> deleted_edges;
  deleted_edges.reserve(3);


  // this vector will hold all vertices of face _fh
  // for updating their outgoing halfedge
  std::vector<VertexHandle>  vhandles;
  vhandles.reserve(3);


  // for all halfedges of face _fh do:
  //   1) invalidate face handle.
  //   2) collect all boundary halfedges, set them deleted
  //   3) store vertex handles
  HalfedgeHandle hh;
Jan Möbius's avatar
Jan Möbius committed
527
  for (FaceHalfedgeIter fh_it(fh_iter(_fh)); fh_it.is_valid(); ++fh_it)
Jan Möbius's avatar
Jan Möbius committed
528
  {
Jan Möbius's avatar
Jan Möbius committed
529
    hh = *fh_it;
Jan Möbius's avatar
Jan Möbius committed
530
531
532
533
534
535
536
537
538
539
540

    set_boundary(hh);//set_face_handle(hh, InvalidFaceHandle);

    if (is_boundary(opposite_halfedge_handle(hh)))
        deleted_edges.push_back(edge_handle(hh));

    vhandles.push_back(to_vertex_handle(hh));
  }


  // delete all collected (half)edges
541
  // these edges were all boundary
Jan Möbius's avatar
Jan Möbius committed
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
  // delete isolated vertices (if _delete_isolated_vertices is true)
  if (!deleted_edges.empty())
  {
    std::vector<EdgeHandle>::iterator del_it(deleted_edges.begin()),
                                      del_end(deleted_edges.end());
    HalfedgeHandle h0, h1, next0, next1, prev0, prev1;
    VertexHandle   v0, v1;

    for (; del_it!=del_end; ++del_it)
    {
      h0    = halfedge_handle(*del_it, 0);
      v0    = to_vertex_handle(h0);
      next0 = next_halfedge_handle(h0);
      prev0 = prev_halfedge_handle(h0);

      h1    = halfedge_handle(*del_it, 1);
      v1    = to_vertex_handle(h1);
      next1 = next_halfedge_handle(h1);
      prev1 = prev_halfedge_handle(h1);

      // adjust next and prev handles
      set_next_halfedge_handle(prev0, next1);
      set_next_halfedge_handle(prev1, next0);

566
567
568
      // mark edge deleted if the mesh has a edge status
      if ( has_edge_status() )
    	 status(*del_it).set_deleted(true);
Jan Möbius's avatar
Jan Möbius committed
569

570
571
572

      // mark corresponding halfedges as deleted
      // As the deleted edge is boundary,
573
      // all corresponding halfedges will also be deleted.
574
575
576
577
578
      if ( has_halfedge_status() ) {
        status(h0).set_deleted(true);
        status(h1).set_deleted(true);
      }

Jan Möbius's avatar
Jan Möbius committed
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
      // update v0
      if (halfedge_handle(v0) == h1)
      {
        // isolated ?
        if (next0 == h1)
        {
          if (_delete_isolated_vertices)
            status(v0).set_deleted(true);
          set_isolated(v0);
        }
        else set_halfedge_handle(v0, next0);
      }

      // update v1
      if (halfedge_handle(v1) == h0)
      {
        // isolated ?
        if (next1 == h0)
        {
          if (_delete_isolated_vertices)
            status(v1).set_deleted(true);
          set_isolated(v1);
        }
        else  set_halfedge_handle(v1, next1);
      }
    }
  }

  // update outgoing halfedge handles of remaining vertices
  std::vector<VertexHandle>::iterator v_it(vhandles.begin()),
                                      v_end(vhandles.end());
  for (; v_it!=v_end; ++v_it)
    adjust_outgoing_halfedge(*v_it);
}

614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
//-----------------------------------------------------------------------------
PolyConnectivity::VertexIter PolyConnectivity::vertices_begin()
{
  return VertexIter(*this, VertexHandle(0));
}

//-----------------------------------------------------------------------------
PolyConnectivity::ConstVertexIter PolyConnectivity::vertices_begin() const
{
  return ConstVertexIter(*this, VertexHandle(0));
}

//-----------------------------------------------------------------------------
PolyConnectivity::VertexIter PolyConnectivity::vertices_end()
{
Jan Möbius's avatar
Jan Möbius committed
629
  return VertexIter(*this, VertexHandle( int(n_vertices() ) ));
630
631
632
633
634
}

//-----------------------------------------------------------------------------
PolyConnectivity::ConstVertexIter PolyConnectivity::vertices_end() const
{
Jan Möbius's avatar
Jan Möbius committed
635
  return ConstVertexIter(*this, VertexHandle( int(n_vertices()) ));
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
}

//-----------------------------------------------------------------------------
PolyConnectivity::HalfedgeIter PolyConnectivity::halfedges_begin()
{
  return HalfedgeIter(*this, HalfedgeHandle(0));
}

//-----------------------------------------------------------------------------
PolyConnectivity::ConstHalfedgeIter PolyConnectivity::halfedges_begin() const
{
  return ConstHalfedgeIter(*this, HalfedgeHandle(0));
}

//-----------------------------------------------------------------------------
PolyConnectivity::HalfedgeIter PolyConnectivity::halfedges_end()
{
Jan Möbius's avatar
Jan Möbius committed
653
  return HalfedgeIter(*this, HalfedgeHandle(int(n_halfedges())));
654
655
656
657
658
}

//-----------------------------------------------------------------------------
PolyConnectivity::ConstHalfedgeIter PolyConnectivity::halfedges_end() const
{
Jan Möbius's avatar
Jan Möbius committed
659
  return ConstHalfedgeIter(*this, HalfedgeHandle(int(n_halfedges())));
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
}

//-----------------------------------------------------------------------------
PolyConnectivity::EdgeIter PolyConnectivity::edges_begin()
{
  return EdgeIter(*this, EdgeHandle(0));
}

//-----------------------------------------------------------------------------
PolyConnectivity::ConstEdgeIter PolyConnectivity::edges_begin() const
{
  return ConstEdgeIter(*this, EdgeHandle(0));
}

//-----------------------------------------------------------------------------
PolyConnectivity::EdgeIter PolyConnectivity::edges_end()
{
Jan Möbius's avatar
Jan Möbius committed
677
  return EdgeIter(*this, EdgeHandle(int(n_edges())));
678
679
680
681
682
}

//-----------------------------------------------------------------------------
PolyConnectivity::ConstEdgeIter PolyConnectivity::edges_end() const
{
Jan Möbius's avatar
Jan Möbius committed
683
  return ConstEdgeIter(*this, EdgeHandle(int(n_edges())));
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
}

//-----------------------------------------------------------------------------
PolyConnectivity::FaceIter PolyConnectivity::faces_begin()
{
  return FaceIter(*this, FaceHandle(0));
}

//-----------------------------------------------------------------------------
PolyConnectivity::ConstFaceIter PolyConnectivity::faces_begin() const
{
  return ConstFaceIter(*this, FaceHandle(0));
}

//-----------------------------------------------------------------------------
PolyConnectivity::FaceIter PolyConnectivity::faces_end()
{
Jan Möbius's avatar
Jan Möbius committed
701
  return FaceIter(*this, FaceHandle(int(n_faces())));
702
703
704
705
706
}

//-----------------------------------------------------------------------------
PolyConnectivity::ConstFaceIter PolyConnectivity::faces_end() const
{
Jan Möbius's avatar
Jan Möbius committed
707
  return ConstFaceIter(*this, FaceHandle(int(n_faces())));
708
709
}

Jan Möbius's avatar
Jan Möbius committed
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
//-----------------------------------------------------------------------------
void PolyConnectivity::collapse(HalfedgeHandle _hh)
{
  HalfedgeHandle h0 = _hh;
  HalfedgeHandle h1 = next_halfedge_handle(h0);
  HalfedgeHandle o0 = opposite_halfedge_handle(h0);
  HalfedgeHandle o1 = next_halfedge_handle(o0);

  // remove edge
  collapse_edge(h0);

  // remove loops
  if (next_halfedge_handle(next_halfedge_handle(h1)) == h1)
    collapse_loop(next_halfedge_handle(h1));
  if (next_halfedge_handle(next_halfedge_handle(o1)) == o1)
    collapse_loop(o1);
}

//-----------------------------------------------------------------------------
void PolyConnectivity::collapse_edge(HalfedgeHandle _hh)
{
  HalfedgeHandle  h  = _hh;
  HalfedgeHandle  hn = next_halfedge_handle(h);
  HalfedgeHandle  hp = prev_halfedge_handle(h);

  HalfedgeHandle  o  = opposite_halfedge_handle(h);
  HalfedgeHandle  on = next_halfedge_handle(o);
  HalfedgeHandle  op = prev_halfedge_handle(o);

  FaceHandle      fh = face_handle(h);
  FaceHandle      fo = face_handle(o);

  VertexHandle    vh = to_vertex_handle(h);
  VertexHandle    vo = to_vertex_handle(o);



  // halfedge -> vertex
Jan Möbius's avatar
Jan Möbius committed
748
749
  for (VertexIHalfedgeIter vih_it(vih_iter(vo)); vih_it.is_valid(); ++vih_it)
    set_vertex_handle(*vih_it, vh);
Jan Möbius's avatar
Jan Möbius committed
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


  // halfedge -> halfedge
  set_next_halfedge_handle(hp, hn);
  set_next_halfedge_handle(op, on);


  // face -> halfedge
  if (fh.is_valid())  set_halfedge_handle(fh, hn);
  if (fo.is_valid())  set_halfedge_handle(fo, on);


  // vertex -> halfedge
  if (halfedge_handle(vh) == o)  set_halfedge_handle(vh, hn);
  adjust_outgoing_halfedge(vh);
  set_isolated(vo);

  // delete stuff
  status(edge_handle(h)).set_deleted(true);
  status(vo).set_deleted(true);
}

//-----------------------------------------------------------------------------
void PolyConnectivity::collapse_loop(HalfedgeHandle _hh)
{
  HalfedgeHandle  h0 = _hh;
  HalfedgeHandle  h1 = next_halfedge_handle(h0);

  HalfedgeHandle  o0 = opposite_halfedge_handle(h0);
  HalfedgeHandle  o1 = opposite_halfedge_handle(h1);

  VertexHandle    v0 = to_vertex_handle(h0);
  VertexHandle    v1 = to_vertex_handle(h1);

  FaceHandle      fh = face_handle(h0);
  FaceHandle      fo = face_handle(o0);



  // is it a loop ?
  assert ((next_halfedge_handle(h1) == h0) && (h1 != o0));


  // halfedge -> halfedge
  set_next_halfedge_handle(h1, next_halfedge_handle(o0));
  set_next_halfedge_handle(prev_halfedge_handle(o0), h1);


  // halfedge -> face
  set_face_handle(h1, fo);


  // vertex -> halfedge
  set_halfedge_handle(v0, h1);  adjust_outgoing_halfedge(v0);
  set_halfedge_handle(v1, o1);  adjust_outgoing_halfedge(v1);


  // face -> halfedge
  if (fo.is_valid() && halfedge_handle(fo) == o0)
  {
    set_halfedge_handle(fo, h1);
  }

  // delete stuff
  if (fh.is_valid())  
  {
    set_halfedge_handle(fh, InvalidHalfedgeHandle);
    status(fh).set_deleted(true);
  }
  status(edge_handle(h0)).set_deleted(true);
}

//-----------------------------------------------------------------------------
bool PolyConnectivity::is_simple_link(EdgeHandle _eh) const
{
  HalfedgeHandle heh0 = halfedge_handle(_eh, 0);
  HalfedgeHandle heh1 = halfedge_handle(_eh, 1);
  
  FaceHandle fh0 = face_handle(heh0);//fh0 or fh1 might be a invalid,
  FaceHandle fh1 = face_handle(heh1);//i.e., representing the boundary
  
  HalfedgeHandle next_heh = next_halfedge_handle(heh0);
  while (next_heh != heh0)
  {//check if there are no other edges shared between fh0 & fh1
    if (opposite_face_handle(next_heh) == fh1)
    {
      return false;
    }
    next_heh = next_halfedge_handle(next_heh);
  }
  return true;
}

//-----------------------------------------------------------------------------
bool PolyConnectivity::is_simply_connected(FaceHandle _fh) const
{
  std::set<FaceHandle> nb_fhs;
Jan Möbius's avatar
Jan Möbius committed
847
  for (ConstFaceFaceIter cff_it = cff_iter(_fh); cff_it.is_valid(); ++cff_it)
Jan Möbius's avatar
Jan Möbius committed
848
  {
Jan Möbius's avatar
Jan Möbius committed
849
    if (nb_fhs.find(*cff_it) == nb_fhs.end())
Jan Möbius's avatar
Jan Möbius committed
850
    {
Jan Möbius's avatar
Jan Möbius committed
851
      nb_fhs.insert(*cff_it);
Jan Möbius's avatar
Jan Möbius committed
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
901
902
903
904
905
906
907
908
909
910
911
912
    }
    else
    {//there is more than one link
      return false;
    }
  }
  return true;
}
  
//-----------------------------------------------------------------------------
PolyConnectivity::FaceHandle 
PolyConnectivity::remove_edge(EdgeHandle _eh)
{
  //don't allow "dangling" vertices and edges
  assert(!status(_eh).deleted() && is_simple_link(_eh));
  
  HalfedgeHandle heh0 = halfedge_handle(_eh, 0);
  HalfedgeHandle heh1 = halfedge_handle(_eh, 1);
  
  //deal with the faces
  FaceHandle rem_fh = face_handle(heh0), del_fh = face_handle(heh1);
  if (!del_fh.is_valid())
  {//boundary case - we must delete the rem_fh
    std::swap(del_fh, rem_fh);
  }
  assert(del_fh.is_valid());
/*  for (FaceHalfedgeIter fh_it = fh_iter(del_fh); fh_it; ++fh_it)
  {//set the face handle of the halfedges of del_fh to point to rem_fh
    set_face_handle(fh_it, rem_fh);  
  } */
  //fix the halfedge relations
  HalfedgeHandle prev_heh0 = prev_halfedge_handle(heh0);
  HalfedgeHandle prev_heh1 = prev_halfedge_handle(heh1);

  HalfedgeHandle next_heh0 = next_halfedge_handle(heh0);
  HalfedgeHandle next_heh1 = next_halfedge_handle(heh1);
  
  set_next_halfedge_handle(prev_heh0, next_heh1);
  set_next_halfedge_handle(prev_heh1, next_heh0);
  //correct outgoing vertex handles for the _eh vertices (if needed)
  VertexHandle vh0 = to_vertex_handle(heh0);
  VertexHandle vh1 = to_vertex_handle(heh1);
  
  if (halfedge_handle(vh0) == heh1)
  {
    set_halfedge_handle(vh0, next_heh0);
  }
  if (halfedge_handle(vh1) == heh0)
  {
    set_halfedge_handle(vh1, next_heh1);
  }
  
  //correct the hafledge handle of rem_fh if needed and preserve its first vertex
  if (halfedge_handle(rem_fh) == heh0)
  {//rem_fh is the face at heh0
    set_halfedge_handle(rem_fh, prev_heh1);
  }
  else if (halfedge_handle(rem_fh) == heh1)
  {//rem_fh is the face at heh1
    set_halfedge_handle(rem_fh, prev_heh0);
  }
Jan Möbius's avatar
Jan Möbius committed
913
  for (FaceHalfedgeIter fh_it = fh_iter(rem_fh); fh_it.is_valid(); ++fh_it)
Jan Möbius's avatar
Jan Möbius committed
914
  {//set the face handle of the halfedges of del_fh to point to rem_fh
Jan Möbius's avatar
Jan Möbius committed
915
    set_face_handle(*fh_it, rem_fh);
Jan Möbius's avatar
Jan Möbius committed
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
  } 
  
  status(_eh).set_deleted(true);  
  status(del_fh).set_deleted(true);  
  return rem_fh;//returns the remaining face handle
}

//-----------------------------------------------------------------------------
void PolyConnectivity::reinsert_edge(EdgeHandle _eh)
{
  //this does not work without prev_halfedge_handle
  assert_compile(sizeof(Halfedge) == sizeof(Halfedge_with_prev));
  //shoudl be deleted  
  assert(status(_eh).deleted());
  status(_eh).set_deleted(false);  
  
  HalfedgeHandle heh0 = halfedge_handle(_eh, 0);
  HalfedgeHandle heh1 = halfedge_handle(_eh, 1);
  FaceHandle rem_fh = face_handle(heh0), del_fh = face_handle(heh1);
  if (!del_fh.is_valid())
  {//boundary case - we must delete the rem_fh
    std::swap(del_fh, rem_fh);
  }
  assert(status(del_fh).deleted());
  status(del_fh).set_deleted(false); 
  
  //restore halfedge relations
  HalfedgeHandle prev_heh0 = prev_halfedge_handle(heh0);
  HalfedgeHandle prev_heh1 = prev_halfedge_handle(heh1);

  HalfedgeHandle next_heh0 = next_halfedge_handle(heh0);
  HalfedgeHandle next_heh1 = next_halfedge_handle(heh1);
  
  set_next_halfedge_handle(prev_heh0, heh0);
  set_prev_halfedge_handle(next_heh0, heh0);
  
  set_next_halfedge_handle(prev_heh1, heh1);
  set_prev_halfedge_handle(next_heh1, heh1);
  
Jan Möbius's avatar
Jan Möbius committed
955
  for (FaceHalfedgeIter fh_it = fh_iter(del_fh); fh_it.is_valid(); ++fh_it)
Jan Möbius's avatar
Jan Möbius committed
956
  {//reassign halfedges to del_fh  
Jan Möbius's avatar
Jan Möbius committed
957
    set_face_handle(*fh_it, del_fh);
Jan Möbius's avatar
Jan Möbius committed
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
  }
   
  if (face_handle(halfedge_handle(rem_fh)) == del_fh)
  {//correct the halfedge handle of rem_fh
    if (halfedge_handle(rem_fh) == prev_heh0)
    {//rem_fh is the face at heh1
      set_halfedge_handle(rem_fh, heh1);
    }
    else
    {//rem_fh is the face at heh0
      assert(halfedge_handle(rem_fh) == prev_heh1);
      set_halfedge_handle(rem_fh, heh0);
    }
  }
}

//-----------------------------------------------------------------------------
PolyConnectivity::HalfedgeHandle
PolyConnectivity::insert_edge(HalfedgeHandle _prev_heh, HalfedgeHandle _next_heh)
{
  assert(face_handle(_prev_heh) == face_handle(_next_heh));//only the manifold case
  assert(next_halfedge_handle(_prev_heh) != _next_heh);//this can not be done
  VertexHandle vh0 = to_vertex_handle(_prev_heh);
  VertexHandle vh1 = from_vertex_handle(_next_heh);
  //create the link between vh0 and vh1
  HalfedgeHandle heh0 = new_edge(vh0, vh1);
  HalfedgeHandle heh1 = opposite_halfedge_handle(heh0);
  HalfedgeHandle next_prev_heh = next_halfedge_handle(_prev_heh);
  HalfedgeHandle prev_next_heh = prev_halfedge_handle(_next_heh);
  set_next_halfedge_handle(_prev_heh, heh0);
  set_next_halfedge_handle(heh0, _next_heh);
  set_next_halfedge_handle(prev_next_heh, heh1);
  set_next_halfedge_handle(heh1, next_prev_heh);
  
  //now set the face handles - the new face is assigned to heh0
  FaceHandle new_fh = new_face();
  set_halfedge_handle(new_fh, heh0);
Jan Möbius's avatar
Jan Möbius committed
995
  for (FaceHalfedgeIter fh_it = fh_iter(new_fh); fh_it.is_valid(); ++fh_it)
Jan Möbius's avatar
Jan Möbius committed
996
  {
Jan Möbius's avatar
Jan Möbius committed
997
    set_face_handle(*fh_it, new_fh);
Jan Möbius's avatar
Jan Möbius committed
998
999
1000
  }  
  FaceHandle old_fh = face_handle(next_prev_heh);
  set_face_handle(heh1, old_fh);