Mesh Oriented datABase  (version 5.5.1)
An array-based unstructured mesh library
Intx2MeshInPlane.cpp
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1 /*
2  * Intx2MeshInPlane.cpp
3  *
4  * Created on: Oct 24, 2012
5  * Author: iulian
6  */
7 
9 #include "moab/GeomUtil.hpp"
11 
12 namespace moab
13 {
14 
16 
18 
20 {
21  // the points will be at most ?; they will describe a convex patch, after the points will be
22  // ordered and collapsed (eliminate doubles) the area is not really required get coordinates of
23  // the tgt quad
24  double cellArea = 0;
25  int num_nodes;
26  ErrorCode rval = mb->get_connectivity( tgt, tgtConn, num_nodes );
27  if( MB_SUCCESS != rval ) return 1.; // it should be an error
28 
29  nsTgt = num_nodes;
30 
31  rval = mb->get_coords( tgtConn, num_nodes, &( tgtCoords[0][0] ) );
32  if( MB_SUCCESS != rval ) return 1.; // it should be an error
33 
34  for( int j = 0; j < nsTgt; j++ )
35  {
36  // populate coords in the plane for intersection
37  // they should be oriented correctly, positively
38  tgtCoords2D[2 * j] = tgtCoords[j][0]; // x coordinate,
39  tgtCoords2D[2 * j + 1] = tgtCoords[j][1]; // y coordinate
40  }
41  for( int j = 1; j < nsTgt - 1; j++ )
42  cellArea += IntxUtils::area2D( &tgtCoords2D[0], &tgtCoords2D[2 * j], &tgtCoords2D[2 * j + 2] );
43 
44  return cellArea;
45 }
46 
48  EntityHandle src,
49  double* P,
50  int& nP,
51  double& area,
52  int markb[MAXEDGES],
53  int markr[MAXEDGES],
54  int& nsSrc,
55  int& nsTgt,
56  bool check_boxes_first )
57 {
58 
59  int num_nodes = 0;
60  ErrorCode rval = mb->get_connectivity( src, srcConn, num_nodes );MB_CHK_ERR( rval );
61 
62  nsSrc = num_nodes;
63  rval = mb->get_coords( srcConn, num_nodes, &( srcCoords[0][0] ) );MB_CHK_ERR( rval );
64 
65  area = 0.;
66  nP = 0; // number of intersection points we are marking the boundary of src!
67  if( check_boxes_first )
68  {
69  setup_tgt_cell( tgt, nsTgt ); // we do not need area here
70  // look at the boxes formed with vertices; if they are far away, return false early
72  return MB_SUCCESS; // no error, but no intersection, decide early to get out
73  }
74 #ifdef ENABLE_DEBUG
75  if( dbg_1 )
76  {
77  std::cout << "tgt " << mb->id_from_handle( tgt ) << "\n";
78  for( int j = 0; j < nsTgt; j++ )
79  {
80  std::cout << tgtCoords[j] << "\n";
81  }
82  std::cout << "src " << mb->id_from_handle( src ) << "\n";
83  for( int j = 0; j < nsSrc; j++ )
84  {
85  std::cout << srcCoords[j] << "\n";
86  }
87  mb->list_entities( &tgt, 1 );
88  mb->list_entities( &src, 1 );
89  }
90 #endif
91 
92  for( int j = 0; j < nsSrc; j++ )
93  {
94  srcCoords2D[2 * j] = srcCoords[j][0]; // x coordinate,
95  srcCoords2D[2 * j + 1] = srcCoords[j][1]; // y coordinate
96  }
97 #ifdef ENABLE_DEBUG
98  if( dbg_1 )
99  {
100  // std::cout << "gnomonic plane: " << plane << "\n";
101  std::cout << " tgt \n";
102  for( int j = 0; j < nsTgt; j++ )
103  {
104  std::cout << tgtCoords2D[2 * j] << " " << tgtCoords2D[2 * j + 1] << "\n ";
105  }
106  std::cout << " src\n";
107  for( int j = 0; j < nsSrc; j++ )
108  {
109  std::cout << srcCoords2D[2 * j] << " " << srcCoords2D[2 * j + 1] << "\n";
110  }
111  }
112 #endif
113 
114  rval = IntxUtils::EdgeIntersections2( srcCoords2D, nsSrc, tgtCoords2D, nsTgt, markb, markr, P, nP );MB_CHK_ERR( rval );
115 #ifdef ENABLE_DEBUG
116  if( dbg_1 )
117  {
118  for( int k = 0; k < 3; k++ )
119  {
120  std::cout << " markb, markr: " << k << " " << markb[k] << " " << markr[k] << "\n";
121  }
122  }
123 #endif
124 
125  int side[MAXEDGES] = { 0 }; // this refers to what side? src or tgt?
126  int extraPoints =
127  IntxUtils::borderPointsOfXinY2( srcCoords2D, nsSrc, tgtCoords2D, nsTgt, &( P[2 * nP] ), side, epsilon_area );
128  if( extraPoints >= 1 )
129  {
130  for( int k = 0; k < nsSrc; k++ )
131  {
132  if( side[k] )
133  {
134  // this means that vertex k of src is inside convex tgt; mark edges k-1 and k in
135  // src,
136  // as being "intersected" by tgt; (even though they might not be intersected by
137  // other edges, the fact that their apex is inside, is good enough)
138  markb[k] = 1;
139  markb[( k + nsSrc - 1 ) % nsSrc] =
140  1; // it is the previous edge, actually, but instead of doing -1, it is
141  // better to do modulo +3 (modulo 4)
142  // null side b for next call
143  side[k] = 0;
144  }
145  }
146  }
147 #ifdef ENABLE_DEBUG
148  if( dbg_1 )
149  {
150  for( int k = 0; k < 3; k++ )
151  {
152  std::cout << " markb, markr: " << k << " " << markb[k] << " " << markr[k] << "\n";
153  }
154  }
155 #endif
156  nP += extraPoints;
157 
158  extraPoints =
159  IntxUtils::borderPointsOfXinY2( tgtCoords2D, nsTgt, srcCoords2D, nsSrc, &( P[2 * nP] ), side, epsilon_area );
160  if( extraPoints >= 1 )
161  {
162  for( int k = 0; k < nsTgt; k++ )
163  {
164  if( side[k] )
165  {
166  // this is to mark that tgt edges k-1 and k are intersecting src
167  markr[k] = 1;
168  markr[( k + nsTgt - 1 ) % nsTgt] =
169  1; // it is the previous edge, actually, but instead of doing -1, it is
170  // better to do modulo +3 (modulo 4)
171  // null side b for next call
172  }
173  }
174  }
175 #ifdef ENABLE_DEBUG
176  if( dbg_1 )
177  {
178  for( int k = 0; k < 3; k++ )
179  {
180  std::cout << " markb, markr: " << k << " " << markb[k] << " " << markr[k] << "\n";
181  }
182  }
183 #endif
184  nP += extraPoints;
185 
186  // now sort and orient the points in P, such that they are forming a convex polygon
187  // this will be the foundation of our new mesh
188  // this works if the polygons are convex
189  IntxUtils::SortAndRemoveDoubles2( P, nP, epsilon_1 ); // nP should be at most 8 in the end ?
190  // if there are more than 3 points, some area will be positive
191 
192  if( nP >= 3 )
193  {
194  for( int k = 1; k < nP - 1; k++ )
195  area += IntxUtils::area2D( P, &P[2 * k], &P[2 * k + 2] );
196  }
197 
198  return MB_SUCCESS; // no error
199 }
200 
201 // this method will also construct the triangles/polygons in the new mesh
202 // if we accept planar polygons, we just save them
203 // also, we could just create new vertices every time, and merge only in the end;
204 // could be too expensive, and the tolerance for merging could be an
205 // interesting topic
206 ErrorCode Intx2MeshInPlane::findNodes( EntityHandle tgt, int nsTgt, EntityHandle src, int nsSrc, double* iP, int nP )
207 {
208  // except for gnomonic projection, everything is the same as spherical intx
209  // start copy
210  // first of all, check against tgt and src vertices
211  //
212 #ifdef ENABLE_DEBUG
213  if( dbg_1 )
214  {
215  std::cout << "tgt, src, nP, P " << mb->id_from_handle( tgt ) << " " << mb->id_from_handle( src ) << " " << nP
216  << "\n";
217  for( int n = 0; n < nP; n++ )
218  std::cout << " \t" << iP[2 * n] << "\t" << iP[2 * n + 1] << "\n";
219  }
220 #endif
221 
222  // get the edges for the tgt triangle; the extra points will be on those edges, saved as
223  // lists (unordetgt)
224 
225  // first get the list of edges adjacent to the tgt cell
226  // use the neighTgtEdgeTag
227  EntityHandle adjTgtEdges[MAXEDGES];
228  ErrorCode rval = mb->tag_get_data( neighTgtEdgeTag, &tgt, 1, &( adjTgtEdges[0] ) );MB_CHK_SET_ERR( rval, "can't get edge tgt tag" );
229  // we know that we have only nsTgt edges here; [nsTgt, MAXEDGES) are ignored, but it is small
230  // potatoes
231 
232  // these will be in the new mesh, mbOut
233  // some of them will be handles to the initial vertices from src or tgt meshes (lagr or euler)
234 
235  EntityHandle* foundIds = new EntityHandle[nP];
236  for( int i = 0; i < nP; i++ )
237  {
238  double* pp = &iP[2 * i]; // iP+2*i
239  //
240  CartVect pos( pp[0], pp[1], 0. );
241  int found = 0;
242  // first, are they on vertices from tgt or src?
243  // priority is the tgt mesh (mb2?)
244  int j = 0;
245  EntityHandle outNode = (EntityHandle)0;
246  for( j = 0; j < nsTgt && !found; j++ )
247  {
248  // int node = tgtTri.v[j];
249  double d2 = IntxUtils::dist2( pp, &tgtCoords2D[2 * j] );
250  if( d2 < epsilon_1 )
251  {
252 
253  foundIds[i] = tgtConn[j]; // no new node
254  found = 1;
255 #ifdef ENABLE_DEBUG
256  if( dbg_1 )
257  std::cout << " tgt node j:" << j << " id:" << mb->id_from_handle( tgtConn[j] )
258  << " 2d coords:" << tgtCoords2D[2 * j] << " " << tgtCoords2D[2 * j + 1] << " d2: " << d2
259  << " \n";
260 #endif
261  }
262  }
263 
264  for( j = 0; j < nsSrc && !found; j++ )
265  {
266  // int node = srcTri.v[j];
267  double d2 = IntxUtils::dist2( pp, &srcCoords2D[2 * j] );
268  if( d2 < epsilon_1 )
269  {
270  // suspect is srcConn[j] corresponding in mbOut
271 
272  foundIds[i] = srcConn[j]; // no new node
273  found = 1;
274 #ifdef ENABLE_DEBUG
275  if( dbg_1 )
276  std::cout << " src node " << j << " " << mb->id_from_handle( srcConn[j] ) << " d2:" << d2 << " \n";
277 #endif
278  }
279  }
280  if( !found )
281  {
282  // find the edge it belongs, first, on the tgt element
283  //
284  for( j = 0; j < nsTgt; j++ )
285  {
286  int j1 = ( j + 1 ) % nsTgt;
287  double area = IntxUtils::area2D( &tgtCoords2D[2 * j], &tgtCoords2D[2 * j1], pp );
288 #ifdef ENABLE_DEBUG
289  if( dbg_1 )
290  std::cout << " edge " << j << ": " << mb->id_from_handle( adjTgtEdges[j] ) << " " << tgtConn[j]
291  << " " << tgtConn[j1] << " area : " << area << "\n";
292 #endif
293  if( fabs( area ) < epsilon_1 / 2 )
294  {
295  // found the edge; now find if there is a point in the list here
296  // std::vector<EntityHandle> * expts = extraNodesMap[tgtEdges[j]];
297  int indx = TgtEdges.index( adjTgtEdges[j] );
298  if( indx < 0 ) // CID 181166 (#1 of 1): Argument cannot be negative (NEGATIVE_RETURNS)
299  {
300  std::cerr << " error in adjacent tgt edge: " << mb->id_from_handle( adjTgtEdges[j] ) << "\n";
301  delete[] foundIds;
302  return MB_FAILURE;
303  }
304  std::vector< EntityHandle >* expts = extraNodesVec[indx];
305  // if the points pp is between extra points, then just give that id
306  // if not, create a new point, (check the id)
307  // get the coordinates of the extra points so far
308  int nbExtraNodesSoFar = expts->size();
309  if( nbExtraNodesSoFar > 0 )
310  {
311  CartVect* coords1 = new CartVect[nbExtraNodesSoFar];
312  mb->get_coords( &( *expts )[0], nbExtraNodesSoFar, &( coords1[0][0] ) );
313  // std::list<int>::iterator it;
314  for( int k = 0; k < nbExtraNodesSoFar && !found; k++ )
315  {
316  // int pnt = *it;
317  double d3 = ( pos - coords1[k] ).length_squared();
318  if( d3 < epsilon_1 )
319  {
320  found = 1;
321  foundIds[i] = ( *expts )[k];
322 #ifdef ENABLE_DEBUG
323  if( dbg_1 ) std::cout << " found node:" << foundIds[i] << std::endl;
324 #endif
325  }
326  }
327  delete[] coords1;
328  }
329 
330  if( !found )
331  {
332  // create a new point in 2d (at the intersection)
333  // foundIds[i] = m_num2dPoints;
334  // expts.push_back(m_num2dPoints);
335  // need to create a new node in mbOut
336  // this will be on the edge, and it will be added to the local list
337  mb->create_vertex( pos.array(), outNode );
338  ( *expts ).push_back( outNode );
339  foundIds[i] = outNode;
340  found = 1;
341 #ifdef ENABLE_DEBUG
342  if( dbg_1 ) std::cout << " new node: " << outNode << std::endl;
343 #endif
344  }
345  }
346  }
347  }
348  if( !found )
349  {
350  std::cout << " tgt polygon: ";
351  for( int j1 = 0; j1 < nsTgt; j1++ )
352  {
353  std::cout << tgtCoords2D[2 * j1] << " " << tgtCoords2D[2 * j1 + 1] << "\n";
354  }
355  std::cout << " a point pp is not on a tgt polygon " << *pp << " " << pp[1] << " tgt polygon "
356  << mb->id_from_handle( tgt ) << " \n";
357  delete[] foundIds;
358  return MB_FAILURE;
359  }
360  }
361 #ifdef ENABLE_DEBUG
362  if( dbg_1 )
363  {
364  std::cout << " candidate polygon: nP " << nP << "\n";
365  for( int i1 = 0; i1 < nP; i1++ )
366  std::cout << iP[2 * i1] << " " << iP[2 * i1 + 1] << " " << foundIds[i1] << "\n";
367  }
368 #endif
369  // first, find out if we have nodes collapsed; shrink them
370  // we may have to reduce nP
371  // it is possible that some nodes are collapsed after intersection only
372  // nodes will always be in order (convex intersection)
373  correct_polygon( foundIds, nP );
374  // now we can build the triangles, from P array, with foundIds
375  // we will put them in the out set
376  if( nP >= 3 )
377  {
378  EntityHandle polyNew;
379  mb->create_element( MBPOLYGON, foundIds, nP, polyNew );
380  mb->add_entities( outSet, &polyNew, 1 );
381 
382  // tag it with the index ids from tgt and src sets
383  int id = rs1.index( src ); // index starts from 0
384  mb->tag_set_data( srcParentTag, &polyNew, 1, &id );
385  id = rs2.index( tgt );
386  mb->tag_set_data( tgtParentTag, &polyNew, 1, &id );
387 
388  counting++;
389  mb->tag_set_data( countTag, &polyNew, 1, &counting );
390 
391 #ifdef ENABLE_DEBUG
392  if( dbg_1 )
393  {
394 
395  std::cout << "Count: " << counting + 1 << "\n";
396  std::cout << " polygon " << mb->id_from_handle( polyNew ) << " nodes: " << nP << " :";
397  for( int i1 = 0; i1 < nP; i1++ )
398  std::cout << " " << mb->id_from_handle( foundIds[i1] );
399  std::cout << "\n";
400  std::vector< CartVect > posi( nP );
401  mb->get_coords( foundIds, nP, &( posi[0][0] ) );
402  for( int i1 = 0; i1 < nP; i1++ )
403  std::cout << iP[2 * i1] << " " << iP[2 * i1 + 1] << " " << posi[i1] << "\n";
404 
405  std::stringstream fff;
406  fff << "file0" << counting << ".vtk";
407  mb->write_mesh( fff.str().c_str(), &outSet, 1 );
408  }
409 #endif
410  }
411  delete[] foundIds;
412  foundIds = NULL;
413  return MB_SUCCESS;
414  // end copy
415 }
416 
417 } // end namespace moab