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
#ifndef QUADCLEAN_H
#define QUADCLEAN_H

////////////////////////////////////////////////////////////////////////////////
//                      Quad-Cleanup
//
// Developed by:  Chaman Singh Verma
//                Department of Computer Sciences.
//                The University of Wisconsin, Madison
//
// Work Supported by:
//                 Dr. Tim Tautges
//                 Argonne National Lab, Chicago
//
//
// Objective:  Given a quadrilateral mesh, this class implements various strategies
// to improve the quadrilateral mesh both geometrically and topologically. The
// Laplacian ( local and global ) is used for geometric quality improvement, and for
// topological improvements various operations are used.
// The two basis operations for topological improvements are
//  1)   Face close
//  2)   doublet insertion and removal.
//

// Reference Papers:
//  1) Topological Improvement Procedures for Quadrilateral Finite Element Meshes
//     S.A. Canann,  S.N. Muthikrishnan and R.K. Phillips

//  2) Automated All Quadrilateral Mesh Adaptation Through Refinment and Coarsening
//     Bret Dallas Anderson
//     Master Thesis, Brigham Young University.
//
//  3) Non-Local Topological Clean-Up ( The idea of yring  is from this paper)
//     Guy Bunin.
//
// For suggestios, bugs and criticisms, please send e-mail to
//                      [email protected]
//
// Last Date update:  16th Feb 2010.
//
///////////////////////////////////////////////////////////////////////////////////

#include "meshkit/Mesh.hpp"
#include "meshkit/Tri2Quad.hpp"
#include "meshkit/basic_math.hpp"
#include "meshkit/StopWatch.hpp"
#include "meshkit/tfiblend.hpp"

#include "meshkit/DijkstraShortestPath.hpp"
#include "meshkit/QuadPatchRemesh.hpp"

extern double area_of_poly3d(int n, double *x, double *y, double *z);

namespace Jaal {

struct FirstIrregularNode : public MeshFilter {
     bool pass( const Vertex *vertex ) const {
          if( vertex->isBoundary() ) return 1;
          if( vertex->getNumRelations(2) != 4 ) return 0;
          return 1;
     }
};

///////////////////////////////////////////////////////////////////////////////////
// Diamond:  An element whose at least one of the opposite vertex is surrounded by
//           three faces. In many cases, diamonds are essential in the quadrilateral
// mesh and they can not be removed, Finding the minimum number of diamonds is hard,
// and we are working towards it.
///////////////////////////////////////////////////////////////////////////////////

class FaceClose {
public:

     FaceClose(Mesh *m, Face *f, Vertex *v0, Vertex *v1) {
          mesh = m;
          face = f;
          vertex0 = v0;
          vertex2 = v1;
          replacedNode = NULL;
     }

     ~FaceClose() {
          if( replacedNode ) delete replacedNode;
     }

     int remove();

     int build();
     int commit();

     Mesh *mesh;
     Face *face;
     Vertex *vertex0, *vertex2;
     Vertex *replacedNode;
private:
     bool isSafe() const;
     int  backup();
     int  rollback();
};

///////////////////////////////////////////////////////////////////////////////////

struct Diamond {

     Diamond(Mesh *m, Face *f, int p) {
          mesh = m;
          face = f;
          position = p;
          faceclose = NULL;
          vertex0   = NULL;
          vertex2   = NULL;

          if (position == 0 || position == 2) {
               vertex0 = face->getNodeAt(0);
               vertex2 = face->getNodeAt(2);
          }

          if (position == 1 || position == 3) {
               vertex0 = face->getNodeAt(1);
               vertex2 = face->getNodeAt(3);
          }
     }
     ~Diamond() {
          if( faceclose) delete faceclose;
     }

     int remove();
     int commit();
     int isSafe();
     int makeShield();

     bool operator<(const Diamond & rhs) const {
          return face->getArea() < rhs.face->getArea();
     }

     Vertex * getNewNode() const {
          if (faceclose) return faceclose->replacedNode;
          return NULL;
     }

     double getDiagonalRatio() const {
          Vertex *v0 = face->getNodeAt((position + 0) % 4);
          Vertex *v1 = face->getNodeAt((position + 1) % 4);
          Vertex *v2 = face->getNodeAt((position + 2) % 4);
          Vertex *v3 = face->getNodeAt((position + 3) % 4);
          double len0 = Vertex::length(v0, v2);
          double len1 = Vertex::length(v1, v3);
          return len0 / len1;
     }
     int build();

     Face *face;
private:
     Vertex *vertex0, *vertex2;
     Mesh *mesh;
     int position;
     FaceClose *faceclose;
};

///////////////////////////////////////////////////////////////////////////////////

struct Doublet {

     Doublet(Mesh *m, Vertex * v) {<--- Member variable 'Doublet::shield' is not initialized in the constructor.
          mesh = m;
          vertex = v;
          replacedFace = NULL;
     }

     bool isSafe() const;
     void makeShield();
     int remove();

     Mesh *mesh;
     Vertex *vertex;
     Face *replacedFace;
     Face * shield[2];
};

///////////////////////////////////////////////////////////////////////////////////

struct Singlet {
     Singlet(Mesh *m, Vertex * v) {
          mesh = m;
          vertex = v;
          active = 1;
     }

     int remove();

private:
     Mesh *mesh;
     Vertex *vertex;
     bool active;
     NodeSequence oldNodes, newNodes;
     FaceSequence oldFaces, newFaces;

     int remove_by_refinement();
     int remove_by_swapping();

     int commit();
     void clear();
};

/////////////////////////////////////////////////////////////////////////////////////

class OneDefectPatch {
public:
     static size_t MAX_FACES_ALLOWED;

     static size_t num_boundaries;
     static double exec_time;
     static size_t num_3_patches;
     static size_t num_4_patches;
     static size_t num_5_patches;
     static size_t disk_remeshable;

     OneDefectPatch( Mesh *m ) {<--- Member variable 'OneDefectPatch::quad_splitting_node_degree' is not initialized in the constructor.<--- Member variable 'OneDefectPatch::partSegments' is not initialized in the constructor.
          mesh = m;
          apex = NULL;
          quad_splitting_node = NULL;
          new_defective_node  = NULL;
     }

     OneDefectPatch( Mesh *m, Vertex *v) {<--- Member variable 'OneDefectPatch::quad_splitting_node_degree' is not initialized in the constructor.<--- Member variable 'OneDefectPatch::partSegments' is not initialized in the constructor.
          mesh = m;
          apex = v;
          quad_splitting_node = NULL;
          new_defective_node  = NULL;
     }

     void set_initial_path( const NodeSequence &sq) {
          nodepath = sq;
     }

     size_t getSize(int e) const {
          if( e == 0) return inner_nodes.size() + bound_nodes.size();
          if( e == 2) return faces.size();
          return 0;
     }

     const NodeSequence &get_irregular_nodes_removed() {
          return irregular_nodes_removed;
     }

     bool isBoundaryEven() const {
          if( bound_nodes.size()%2 == 0 ) return 1;
          return 1;
     }

     size_t count_irregular_nodes(int where);

     int  build_remeshable_boundary();

     double get_isoperimetic_quotient() const {
          // This definiation is taken from Wikipedia..
          double A = getArea();
          double L = getPerimeter();
          double q = 4*M_PI*A/(L*L);
          return q;
     }

     void getFaces( FaceSequence &result) const {
          size_t nSize = faces.size();

          result.clear();
          if( nSize == 0 ) return;

          result.resize( nSize );

          int index = 0;
          FaceSet::const_iterator it;
          for( it = faces.begin(); it != faces.end(); ++it)
               result[index++] = *it;
     }

     const NodeSequence &getBoundaryNodes() const {
          return bound_nodes;
     }

     bool operator < ( const OneDefectPatch &rhs) const {
          return getSize(2) < rhs.getSize(2);
     }

     Vertex *get_new_defective_node() {
          return new_defective_node;
     }

     int  remesh();

     void setAttributes();

     void clear() {
          nodepath.clear();
          new_defective_node  = NULL;
          quad_splitting_node = NULL;
          corners.clear();
          inner_nodes.clear();
          bound_nodes.clear();
          faces.clear();
          inner_faces.clear();
          irregular_nodes_removed.clear();
          boundary.clear();
          cornerPos.clear();
          segSize.clear();
          newnodes.clear();
          newfaces.clear();
     }

private:
     bool isSafe();

     // Input data.
     Mesh   *mesh;
     Vertex *apex;               // Seed: Irregular vertex to start from.
     NodeSequence  nodepath;     // Initial joining two irregular nodes..

     FaceSet faces;
     FaceSet inner_faces;

#ifdef USE_HASHMAP
     std::tr1::unordered_map<Vertex*, FaceSet> relations02;
     std::tr1::unordered_map<Vertex*, FaceSet>::iterator miter;
//   std::tr1::unordered_set<Face*> inner_faces;
#else
     std::map<Vertex*, FaceSet> relations02;
     std::map<Vertex*, FaceSet>::iterator miter;
#endif

     Vertex *new_defective_node;

     // Local data ...
     Vertex *quad_splitting_node;     // One special node that splits a quad loop
     int quad_splitting_node_degree;  // Valence of the splitting node.

     NodeSet corners;                 // Corners of the blob
     NodeSet nodes;                   // All the nodes (inner + boundary)
     NodeSequence inner_nodes;        // Inner nodes (not on the boundary ) of the blob
     NodeSequence bound_nodes;        // Boundary nodes
     NodeSequence irregular_nodes_removed;

     vector<Edge> boundary;          // boundary of the blob.
     vector<int>  cornerPos;         // Positions of the corners in the bound_nodes.
     vector<int>  segSize;
     int   partSegments[10];

     TriRemeshTemplate    template3;
     QuadRemeshTemplate   template4;
     PentaRemeshTemplate  template5;

     // Variable used in 3-5 sided patch...
     NodeSequence anodes, bnodes, cnodes, dnodes, enodes;  // Nodes on each segment.

     // Variables used in 4 sided patch..
     NodeSequence a1nodes, a2nodes, b1nodes, c0nodes, c1nodes, c2nodes,
     abnodes, canodes, bcnodes, d1nodes;

     // New nodes and faces in the patch...
     NodeSequence  newnodes, nnodes;
     FaceSequence  newfaces, nfaces;

     // Get the position on the boundary ...
     int getPosOf( const Vertex *v) const {
          size_t nSize = bound_nodes.size();
          for (size_t i = 0; i <  nSize; i++)
               if (bound_nodes[i] == v) return i;
          return -1;
     }
     // Return nodes within the range (src, dst)
     void get_bound_nodes( const Vertex *src, const Vertex *dst, NodeSequence &s);

     // randomly select one irregular node
     bool  has_irregular_node_on_first_segment() const;

     // re-orient boundary nodes so that it starts from a given vertex.
     void start_boundary_loop_from (Vertex *v);

     // re-orient loops ...
     int reorient_4_sided_loop();

     // Patch creation functions...
     int   init_blob();
     int   update_boundary();
     int   finalize_boundary();
     int   expand_blob(Vertex *v);
     int   expand_blob();
     int   get_topological_outer_angle( Vertex *v);
     bool  is_simply_connected();

     bool  is_quad_breakable_at( const Vertex *v);
     // Query for the validity of 3-4-5 sided patches.
     bool  is_4_sided_convex_loop_quad_meshable();

     // Set the boundary pattern string.
     void set_boundary_segments();

     // If the resulting mesh is invalid for some reasons, revert back to
     // original and restore all information.
     void rollback();

     void pre_remesh();  // Before we start remeshing, do some clean-up
     int  remesh_3_sided_patch();
     int  remesh_4_sided_patch();
     int  remesh_5_sided_patch();
     void local_smoothing();
     void post_remesh(); // After successful remeshing, do some clean-up

     double getArea() const {
          double a = 0.0;
          FaceSet::const_iterator it;
          assert( faces.size() );
          for( it = faces.begin(); it != faces.end(); ++it) {
               a += fabs( (*it)->getArea() );
          }
          return a;
     }

     double getPerimeter() const {
          double l = 0.0;
          int nSize = bound_nodes.size();
          for( int i = 0; i < nSize; i++)
               l += Vertex::length( bound_nodes[i], bound_nodes[(i+1)%nSize] );
          return l;
     }

};

/////////////////////////////////////////////////////////////////////////////////////

class QuadCleanUp {
public:
     static bool isDoublet(const Vertex *v);
     static bool isSinglet(const Vertex *v);
     static bool isRegular( const Vertex *v);
     static bool hasSinglet(const Face *f);
     static bool isTunnel(const Edge *e);
     static bool isEdge33(const Edge *e);
     static bool isEdge35(const Edge *e);
     static bool isDiamond(Face *f, int &pos, int type = 33);

     QuadCleanUp() {<--- Member variable 'QuadCleanUp::mesh' is not initialized in the constructor.<--- Member variable 'QuadCleanUp::mopt' is not initialized in the constructor.
          djkpath = NULL;
          defective_patch = NULL;
     }

     QuadCleanUp(Mesh *m) {<--- Member variable 'QuadCleanUp::mopt' is not initialized in the constructor.
          setMesh(m);
          djkpath = NULL;
          defective_patch = NULL;
     }

     ~QuadCleanUp() {
          /*
                    if( lapweight ) delete lapweight;
                    if( lapsmooth ) delete lapsmooth;
          */
          if( djkpath   ) delete djkpath;
          if( defective_patch ) delete defective_patch;
     }

     void setMesh( Mesh *m ) {
          mesh = m;
          /*
                    lapsmooth = new LaplaceSmoothing(mesh);
                    lapweight = new LaplaceLengthWeight;
                    lapsmooth->setWeight( lapweight );
          */
     }

     // Query methods ...
     NodeSequence  search_restricted_nodes();
     FaceSequence  search_restricted_faces();
     FaceSequence  search_flat_quads();

     vector<Diamond> search_diamonds(int type = 33 );
     vector<Singlet> search_boundary_singlets();
     vector<Doublet> search_interior_doublets();
     vector<Edge>    search_tunnels();
     vector<OneDefectPatch> search_one_defect_patches();

     OneDefectPatch* build_one_defect_patch(Vertex *vertex = NULL );

     int  degree_5_dominated();

     // Global Cleanup methods ..
     int remesh_defective_patches();

     // Local Cleanup methods ..
     int reduce_degree( Vertex *v );
     int vertex_degree_reduction();

     int swap_concave_faces();

     // Removal Methods ...
     int  remove_diamonds();
     int  remove_tunnels();
     int  remove_interior_doublets();
     int  remove_boundary_singlets();
     int  remove_bridges();
     int  shift_irregular_nodes();

//  int irregular_nodes_clustering();

     //  void remove_ynodes();
     int  clean_layer(int id);
     void cleanup_boundary(double cutOffAngle = 100.0);
     void advancing_front_cleanup();
     void advancing_front_edges_swap();

     int  automatic();
     void report();

     int atomic_op_swap_edge( Vertex *v0, Vertex *v1);
     int atomic_op_face_close( Face *f);

     // Some Feature that may be obsolete in the next version...
     Vertex* insert_doublet(Face *face);
     Vertex* insert_boundary_doublet(Face *face);
     Vertex* insert_doublet(Face *face, Vertex *v0, Vertex *v2);

//   vector<Edge33>  search_edges33();
//   int remove_edges35();

     int refine_restricted_node(Vertex *resnode, Vertex *bndnode);
     int refine_degree3_faces();
     int refine_bridges_face();
     // Utility functions ...
     void get_strips(Face *face, FaceSequence &strip1, FaceSequence strip2);

     int  reduce_internal_vertex_degree(Vertex *v);
     int  reduce_boundary_vertex_degree(Vertex *v);

private:
     Mesh *mesh;

     MeshOptimization mopt;
     /*
          LaplaceSmoothing *lapsmooth;
          LaplaceWeight *lapweight;
     */

     DijkstraShortestPath *djkpath; // Used in one defect remeshing ....
     OneDefectPatch* defective_patch;

     int  has_interior_nodes_degree_345();

     NodeSequence  irregular_nodes;

     vector<OneDefectPatch>  vDefectPatches;
     vector<Doublet> vDoublets;
     vector<Singlet> vSinglets;
     vector<Diamond> vDiamonds; // Diamonds in the mesh;
     vector<Diamond> search_diamonds_in_layer(int l);

     int clean_layer_once(int id);
     int face_close(Face *face, Vertex *v0, Vertex *v2);
     int diamond_collapse(FaceClose &d);
     int remove_interior_doublet(Doublet &d);
     int remove_boundary_singlet_type1(const Singlet &s);
     int remove_boundary_singlet_type2(const Singlet &s);
     int remove_boundary_singlets_once();
     int remove_bridges_in_layer( int l);
     int remove_bridges_once();
     int remove_diamonds_once();
     int remove_diamonds_in_layer( int l);
     int advance_front_edges_swap_once(int layerid);

     int apply_advance_front_bridge_rule( Vertex *v0, Vertex *v1);
     int apply_advance_front_excess_rule( Vertex *v);
     int apply_advance_front_triplet_rule( Vertex *v);
     int apply_advance_front_singlet_rule( Vertex *v);

     int remove_doublets_once();
     int remove_interior_doublets_once();

     int boundary_vertex_degree_reduction_once();
     int internal_vertex_degree_reduction_once();

     // High level utility function composed of basic functions...
     void cleanup_internal_boundary_face();

     // May become obsolere
     int refine_3434_pattern( Face *face, int pos);
     int refine_3454_pattern( Face *face, int pos);
     int refine_3444_pattern( Face *face, int pos);
     int apply_shift_node3_rule( Vertex *vertex);
};

////////////////////////////////////////////////////////////////////////////////

inline bool
QuadCleanUp::isRegular (const Vertex *v)
{
     assert(v);
     // Any interior vertex having four nodes( or faces ) is a regular node.
     if (!v->isBoundary () && (v->getNumRelations(2) == 4)) return 1;
     return 0;
}

////////////////////////////////////////////////////////////////////////////////

inline bool
QuadCleanUp::isDoublet (const Vertex *v)
{
     assert(v);
     // Any interior node having two neighboring face is a  doublet node.
     if (!v->isBoundary () && (v->getNumRelations(2) == 2)) return 1;
     return 0;
}

////////////////////////////////////////////////////////////////////////////////

inline bool
QuadCleanUp::isSinglet (const Vertex *v)
{
     assert( v );
     // Any boundary node having only one neigbour cell is a singlet node ...
     int numfaces = v->getNumRelations(2);
     assert (numfaces >= 0);
     if (v->isBoundary () && (numfaces == 1)) return 1;
     return 0;
}

////////////////////////////////////////////////////////////////////////////////

inline bool
QuadCleanUp::hasSinglet (const Face *face)
{
     assert( face );

     if( face->isRemoved() ) return 0;

     for (int i = 0; i < face->getSize (0); i++) {
          if (isSinglet (face->getNodeAt (i))) return 1;
     }
     return 0;
}

////////////////////////////////////////////////////////////////////////////////

void set_singlet_tag(Mesh *m, const string &s = "Singlet" );
void set_doublet_tag(Mesh *m, const string &s = "Doublet" );
void set_diamond_tag(Mesh *mesh, const string &s = "Diamond" );

} // namespace Jaal

#endif

///////////////////////////////////////////////////////////////////////////////