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1 /*M///////////////////////////////////////////////////////////////////////////////////////
2 //
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9 //
10 //                        Intel License Agreement
11 //                For Open Source Computer Vision Library
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41 #include "_cv.h"
42 
43 CV_IMPL CvSubdiv2D *
cvCreateSubdiv2D(int subdiv_type,int header_size,int vtx_size,int quadedge_size,CvMemStorage * storage)44 cvCreateSubdiv2D( int subdiv_type, int header_size,
45                   int vtx_size, int quadedge_size, CvMemStorage * storage )
46 {
47     CvSubdiv2D *subdiv = 0;
48 
49     CV_FUNCNAME( "cvCleateSubdiv2D" );
50 
51     __BEGIN__;
52 
53     if( !storage )
54         CV_ERROR( CV_StsNullPtr, "" );
55 
56     if( header_size < (int)sizeof( *subdiv ) ||
57         quadedge_size < (int)sizeof( CvQuadEdge2D ) ||
58         vtx_size < (int)sizeof( CvSubdiv2DPoint ))
59         CV_ERROR_FROM_STATUS( CV_BADSIZE_ERR );
60 
61     subdiv = (CvSubdiv2D *) cvCreateGraph( subdiv_type, header_size,
62                                            vtx_size, quadedge_size, storage );
63 
64 
65     __END__;
66 
67     return subdiv;
68 }
69 
70 
71 /****************************************************************************************\
72 *                                    Quad Edge  algebra                                  *
73 \****************************************************************************************/
74 
75 static CvSubdiv2DEdge
cvSubdiv2DMakeEdge(CvSubdiv2D * subdiv)76 cvSubdiv2DMakeEdge( CvSubdiv2D * subdiv )
77 {
78     CvQuadEdge2D *edge = 0;
79     CvSubdiv2DEdge edgehandle = 0;
80 
81     CV_FUNCNAME( "cvSubdiv2DMakeEdge" );
82 
83     __BEGIN__;
84 
85     if( !subdiv )
86         CV_ERROR( CV_StsNullPtr, "" );
87 
88     edge = (CvQuadEdge2D*)cvSetNew( (CvSet*)subdiv->edges );
89     CV_CHECK();
90 
91     memset( edge->pt, 0, sizeof( edge->pt ));
92     edgehandle = (CvSubdiv2DEdge) edge;
93 
94     edge->next[0] = edgehandle;
95     edge->next[1] = edgehandle + 3;
96     edge->next[2] = edgehandle + 2;
97     edge->next[3] = edgehandle + 1;
98 
99     subdiv->quad_edges++;
100 
101 
102     __END__;
103 
104     return edgehandle;
105 }
106 
107 
108 static CvSubdiv2DPoint *
cvSubdiv2DAddPoint(CvSubdiv2D * subdiv,CvPoint2D32f pt,int is_virtual)109 cvSubdiv2DAddPoint( CvSubdiv2D * subdiv, CvPoint2D32f pt, int is_virtual )
110 {
111     CvSubdiv2DPoint *subdiv_point = 0;
112 
113     subdiv_point = (CvSubdiv2DPoint*)cvSetNew( (CvSet*)subdiv );
114     if( subdiv_point )
115     {
116         memset( subdiv_point, 0, subdiv->elem_size );
117         subdiv_point->pt = pt;
118         subdiv_point->first = 0;
119         subdiv_point->flags |= is_virtual ? CV_SUBDIV2D_VIRTUAL_POINT_FLAG : 0;
120     }
121 
122     return subdiv_point;
123 }
124 
125 
126 static void
cvSubdiv2DSplice(CvSubdiv2DEdge edgeA,CvSubdiv2DEdge edgeB)127 cvSubdiv2DSplice( CvSubdiv2DEdge edgeA, CvSubdiv2DEdge edgeB )
128 {
129     CvSubdiv2DEdge *a_next = &CV_SUBDIV2D_NEXT_EDGE( edgeA );
130     CvSubdiv2DEdge *b_next = &CV_SUBDIV2D_NEXT_EDGE( edgeB );
131     CvSubdiv2DEdge a_rot = cvSubdiv2DRotateEdge( *a_next, 1 );
132     CvSubdiv2DEdge b_rot = cvSubdiv2DRotateEdge( *b_next, 1 );
133     CvSubdiv2DEdge *a_rot_next = &CV_SUBDIV2D_NEXT_EDGE( a_rot );
134     CvSubdiv2DEdge *b_rot_next = &CV_SUBDIV2D_NEXT_EDGE( b_rot );
135     CvSubdiv2DEdge t;
136 
137     CV_SWAP( *a_next, *b_next, t );
138     CV_SWAP( *a_rot_next, *b_rot_next, t );
139 }
140 
141 
142 static void
cvSubdiv2DSetEdgePoints(CvSubdiv2DEdge edge,CvSubdiv2DPoint * org_pt,CvSubdiv2DPoint * dst_pt)143 cvSubdiv2DSetEdgePoints( CvSubdiv2DEdge edge,
144                          CvSubdiv2DPoint * org_pt, CvSubdiv2DPoint * dst_pt )
145 {
146     CvQuadEdge2D *quadedge = (CvQuadEdge2D *) (edge & ~3);
147 
148     CV_FUNCNAME( "cvSubdiv2DSetEdgePoints" );
149 
150     __BEGIN__;
151 
152     if( !quadedge )
153         CV_ERROR( CV_StsNullPtr, "" );
154 
155     quadedge->pt[edge & 3] = org_pt;
156     quadedge->pt[(edge + 2) & 3] = dst_pt;
157 
158 
159     __END__;
160 }
161 
162 
163 static void
cvSubdiv2DDeleteEdge(CvSubdiv2D * subdiv,CvSubdiv2DEdge edge)164 cvSubdiv2DDeleteEdge( CvSubdiv2D * subdiv, CvSubdiv2DEdge edge )
165 {
166     CvQuadEdge2D *quadedge = (CvQuadEdge2D *) (edge & ~3);
167 
168     CV_FUNCNAME( "cvSubdiv2DDeleteEdge" );
169 
170     __BEGIN__;
171 
172     if( !subdiv || !quadedge )
173         CV_ERROR( CV_StsNullPtr, "" );
174 
175     cvSubdiv2DSplice( edge, cvSubdiv2DGetEdge( edge, CV_PREV_AROUND_ORG ));
176 
177     {
178     CvSubdiv2DEdge sym_edge = cvSubdiv2DSymEdge( edge );
179     cvSubdiv2DSplice( sym_edge, cvSubdiv2DGetEdge( sym_edge, CV_PREV_AROUND_ORG ));
180     }
181 
182     cvSetRemoveByPtr( (CvSet*)(subdiv->edges), quadedge );
183     subdiv->quad_edges--;
184 
185 
186     __END__;
187 }
188 
189 
190 static CvSubdiv2DEdge
cvSubdiv2DConnectEdges(CvSubdiv2D * subdiv,CvSubdiv2DEdge edgeA,CvSubdiv2DEdge edgeB)191 cvSubdiv2DConnectEdges( CvSubdiv2D * subdiv, CvSubdiv2DEdge edgeA, CvSubdiv2DEdge edgeB )
192 {
193     CvSubdiv2DEdge new_edge = 0;
194 
195     CV_FUNCNAME( "cvSubdiv2DConnectPoints" );
196 
197     __BEGIN__;
198 
199     CvSubdiv2DPoint *orgB, *dstA;
200 
201     if( !subdiv )
202         CV_ERROR( CV_StsNullPtr, "" );
203 
204     new_edge = cvSubdiv2DMakeEdge( subdiv );
205 
206     cvSubdiv2DSplice( new_edge, cvSubdiv2DGetEdge( edgeA, CV_NEXT_AROUND_LEFT ));
207     cvSubdiv2DSplice( cvSubdiv2DSymEdge( new_edge ), edgeB );
208 
209     dstA = cvSubdiv2DEdgeDst( edgeA );
210     orgB = cvSubdiv2DEdgeOrg( edgeB );
211     cvSubdiv2DSetEdgePoints( new_edge, dstA, orgB );
212 
213     __END__;
214 
215     return new_edge;
216 }
217 
218 
219 static void
cvSubdiv2DSwapEdges(CvSubdiv2DEdge edge)220 cvSubdiv2DSwapEdges( CvSubdiv2DEdge edge )
221 {
222     CvSubdiv2DEdge sym_edge = cvSubdiv2DSymEdge( edge );
223     CvSubdiv2DEdge a = cvSubdiv2DGetEdge( edge, CV_PREV_AROUND_ORG );
224     CvSubdiv2DEdge b = cvSubdiv2DGetEdge( sym_edge, CV_PREV_AROUND_ORG );
225     CvSubdiv2DPoint *dstB, *dstA;
226 
227     cvSubdiv2DSplice( edge, a );
228     cvSubdiv2DSplice( sym_edge, b );
229 
230     dstA = cvSubdiv2DEdgeDst( a );
231     dstB = cvSubdiv2DEdgeDst( b );
232     cvSubdiv2DSetEdgePoints( edge, dstA, dstB );
233 
234     cvSubdiv2DSplice( edge, cvSubdiv2DGetEdge( a, CV_NEXT_AROUND_LEFT ));
235     cvSubdiv2DSplice( sym_edge, cvSubdiv2DGetEdge( b, CV_NEXT_AROUND_LEFT ));
236 }
237 
238 
239 static int
icvIsRightOf(CvPoint2D32f & pt,CvSubdiv2DEdge edge)240 icvIsRightOf( CvPoint2D32f& pt, CvSubdiv2DEdge edge )
241 {
242     CvSubdiv2DPoint *org = cvSubdiv2DEdgeOrg(edge), *dst = cvSubdiv2DEdgeDst(edge);
243     Cv32suf cw_area;
244     cw_area.f = (float)cvTriangleArea( pt, dst->pt, org->pt );
245 
246     return (cw_area.i > 0)*2 - (cw_area.i*2 != 0);
247 }
248 
249 
250 CV_IMPL CvSubdiv2DPointLocation
cvSubdiv2DLocate(CvSubdiv2D * subdiv,CvPoint2D32f pt,CvSubdiv2DEdge * _edge,CvSubdiv2DPoint ** _point)251 cvSubdiv2DLocate( CvSubdiv2D * subdiv, CvPoint2D32f pt,
252                   CvSubdiv2DEdge * _edge, CvSubdiv2DPoint ** _point )
253 {
254     CvSubdiv2DEdge edge = 0;
255     CvSubdiv2DPoint *point = 0;
256     CvSubdiv2DPointLocation location = CV_PTLOC_ERROR;
257 
258     int i, max_edges;
259     int right_of_curr = 0;
260 
261     CV_FUNCNAME( "cvSubdiv2DLocate" );
262 
263     __BEGIN__;
264 
265     if( !subdiv )
266         CV_ERROR( CV_StsNullPtr, "" );
267 
268     if( !CV_IS_SUBDIV2D(subdiv) )
269         CV_ERROR_FROM_STATUS( CV_BADFLAG_ERR );
270 
271     max_edges = subdiv->quad_edges * 4;
272     edge = subdiv->recent_edge;
273 
274     if( max_edges == 0 )
275         CV_ERROR_FROM_STATUS( CV_BADSIZE_ERR );
276     if( !edge )
277         CV_ERROR_FROM_STATUS( CV_NOTDEFINED_ERR );
278 
279     location = CV_PTLOC_OUTSIDE_RECT;
280     if( pt.x < subdiv->topleft.x || pt.y < subdiv->topleft.y ||
281         pt.x >= subdiv->bottomright.x || pt.y >= subdiv->bottomright.y )
282         CV_ERROR_FROM_STATUS( CV_BADRANGE_ERR );
283 
284     location = CV_PTLOC_ERROR;
285 
286     right_of_curr = icvIsRightOf( pt, edge );
287     if( right_of_curr > 0 )
288     {
289         edge = cvSubdiv2DSymEdge( edge );
290         right_of_curr = -right_of_curr;
291     }
292 
293     for( i = 0; i < max_edges; i++ )
294     {
295         CvSubdiv2DEdge onext_edge = cvSubdiv2DNextEdge( edge );
296         CvSubdiv2DEdge dprev_edge = cvSubdiv2DGetEdge( edge, CV_PREV_AROUND_DST );
297 
298         int right_of_onext = icvIsRightOf( pt, onext_edge );
299         int right_of_dprev = icvIsRightOf( pt, dprev_edge );
300 
301         if( right_of_dprev > 0 )
302         {
303             if( right_of_onext > 0 || (right_of_onext == 0 && right_of_curr == 0) )
304             {
305                 location = CV_PTLOC_INSIDE;
306                 EXIT;
307             }
308             else
309             {
310                 right_of_curr = right_of_onext;
311                 edge = onext_edge;
312             }
313         }
314         else
315         {
316             if( right_of_onext > 0 )
317             {
318                 if( right_of_dprev == 0 && right_of_curr == 0 )
319                 {
320                     location = CV_PTLOC_INSIDE;
321                     EXIT;
322                 }
323                 else
324                 {
325                     right_of_curr = right_of_dprev;
326                     edge = dprev_edge;
327                 }
328             }
329             else if( right_of_curr == 0 &&
330                      icvIsRightOf( cvSubdiv2DEdgeDst( onext_edge )->pt, edge ) >= 0 )
331             {
332                 edge = cvSubdiv2DSymEdge( edge );
333             }
334             else
335             {
336                 right_of_curr = right_of_onext;
337                 edge = onext_edge;
338             }
339         }
340     }
341 
342 
343     __END__;
344 
345     subdiv->recent_edge = edge;
346 
347     if( location == CV_PTLOC_INSIDE )
348     {
349         double t1, t2, t3;
350         CvPoint2D32f org_pt = cvSubdiv2DEdgeOrg( edge )->pt;
351         CvPoint2D32f dst_pt = cvSubdiv2DEdgeDst( edge )->pt;
352 
353         t1 = fabs( pt.x - org_pt.x );
354         t1 += fabs( pt.y - org_pt.y );
355         t2 = fabs( pt.x - dst_pt.x );
356         t2 += fabs( pt.y - dst_pt.y );
357         t3 = fabs( org_pt.x - dst_pt.x );
358         t3 += fabs( org_pt.y - dst_pt.y );
359 
360         if( t1 < FLT_EPSILON )
361         {
362             location = CV_PTLOC_VERTEX;
363             point = cvSubdiv2DEdgeOrg( edge );
364             edge = 0;
365         }
366         else if( t2 < FLT_EPSILON )
367         {
368             location = CV_PTLOC_VERTEX;
369             point = cvSubdiv2DEdgeDst( edge );
370             edge = 0;
371         }
372         else if( (t1 < t3 || t2 < t3) &&
373                  fabs( cvTriangleArea( pt, org_pt, dst_pt )) < FLT_EPSILON )
374         {
375             location = CV_PTLOC_ON_EDGE;
376             point = 0;
377         }
378     }
379 
380     if( location == CV_PTLOC_ERROR )
381     {
382         edge = 0;
383         point = 0;
384     }
385 
386     if( _edge )
387         *_edge = edge;
388     if( _point )
389         *_point = point;
390 
391     return location;
392 }
393 
394 
395 CV_INLINE int
icvIsPtInCircle3(CvPoint2D32f pt,CvPoint2D32f a,CvPoint2D32f b,CvPoint2D32f c)396 icvIsPtInCircle3( CvPoint2D32f pt, CvPoint2D32f a, CvPoint2D32f b, CvPoint2D32f c )
397 {
398     double val = (a.x * a.x + a.y * a.y) * cvTriangleArea( b, c, pt );
399     val -= (b.x * b.x + b.y * b.y) * cvTriangleArea( a, c, pt );
400     val += (c.x * c.x + c.y * c.y) * cvTriangleArea( a, b, pt );
401     val -= (pt.x * pt.x + pt.y * pt.y) * cvTriangleArea( a, b, c );
402 
403     return val > FLT_EPSILON ? 1 : val < -FLT_EPSILON ? -1 : 0;
404 }
405 
406 
407 CV_IMPL CvSubdiv2DPoint *
cvSubdivDelaunay2DInsert(CvSubdiv2D * subdiv,CvPoint2D32f pt)408 cvSubdivDelaunay2DInsert( CvSubdiv2D * subdiv, CvPoint2D32f pt )
409 {
410     CvSubdiv2DPoint *point = 0;
411     CvSubdiv2DPointLocation location = CV_PTLOC_ERROR;
412 
413     CvSubdiv2DPoint *curr_point = 0, *first_point = 0;
414     CvSubdiv2DEdge curr_edge = 0, deleted_edge = 0, base_edge = 0;
415     int i, max_edges;
416 
417     CV_FUNCNAME( "cvSubdivDelaunay2DInsert" );
418 
419     __BEGIN__;
420 
421     if( !subdiv )
422         CV_ERROR( CV_StsNullPtr, "" );
423 
424     if( !CV_IS_SUBDIV2D(subdiv) )
425         CV_ERROR_FROM_STATUS( CV_BADFLAG_ERR );
426 
427 
428     location = cvSubdiv2DLocate( subdiv, pt, &curr_edge, &curr_point );
429 
430     switch (location)
431     {
432     case CV_PTLOC_ERROR:
433         CV_ERROR_FROM_STATUS( CV_BADSIZE_ERR );
434 
435     case CV_PTLOC_OUTSIDE_RECT:
436         CV_ERROR_FROM_STATUS( CV_BADRANGE_ERR );
437 
438     case CV_PTLOC_VERTEX:
439         point = curr_point;
440         break;
441 
442     case CV_PTLOC_ON_EDGE:
443         deleted_edge = curr_edge;
444         subdiv->recent_edge = curr_edge = cvSubdiv2DGetEdge( curr_edge, CV_PREV_AROUND_ORG );
445         cvSubdiv2DDeleteEdge( subdiv, deleted_edge );
446         /* no break */
447 
448     case CV_PTLOC_INSIDE:
449 
450         assert( curr_edge != 0 );
451         subdiv->is_geometry_valid = 0;
452 
453         curr_point = cvSubdiv2DAddPoint( subdiv, pt, 0 );
454         CV_CHECK();
455 
456         base_edge = cvSubdiv2DMakeEdge( subdiv );
457         first_point = cvSubdiv2DEdgeOrg( curr_edge );
458         cvSubdiv2DSetEdgePoints( base_edge, first_point, curr_point );
459         cvSubdiv2DSplice( base_edge, curr_edge );
460 
461         do
462         {
463             base_edge = cvSubdiv2DConnectEdges( subdiv, curr_edge,
464                                                 cvSubdiv2DSymEdge( base_edge ));
465             curr_edge = cvSubdiv2DGetEdge( base_edge, CV_PREV_AROUND_ORG );
466         }
467         while( cvSubdiv2DEdgeDst( curr_edge ) != first_point );
468 
469         curr_edge = cvSubdiv2DGetEdge( base_edge, CV_PREV_AROUND_ORG );
470 
471         max_edges = subdiv->quad_edges * 4;
472 
473         for( i = 0; i < max_edges; i++ )
474         {
475             CvSubdiv2DPoint *temp_dst = 0, *curr_org = 0, *curr_dst = 0;
476             CvSubdiv2DEdge temp_edge = cvSubdiv2DGetEdge( curr_edge, CV_PREV_AROUND_ORG );
477 
478             temp_dst = cvSubdiv2DEdgeDst( temp_edge );
479             curr_org = cvSubdiv2DEdgeOrg( curr_edge );
480             curr_dst = cvSubdiv2DEdgeDst( curr_edge );
481 
482             if( icvIsRightOf( temp_dst->pt, curr_edge ) > 0 &&
483                 icvIsPtInCircle3( curr_org->pt, temp_dst->pt,
484                                   curr_dst->pt, curr_point->pt ) < 0 )
485             {
486                 cvSubdiv2DSwapEdges( curr_edge );
487                 curr_edge = cvSubdiv2DGetEdge( curr_edge, CV_PREV_AROUND_ORG );
488             }
489             else if( curr_org == first_point )
490             {
491                 break;
492             }
493             else
494             {
495                 curr_edge = cvSubdiv2DGetEdge( cvSubdiv2DNextEdge( curr_edge ),
496                                                CV_PREV_AROUND_LEFT );
497             }
498         }
499         break;
500     default:
501         assert( 0 );
502         CV_ERROR_FROM_STATUS( CV_NOTDEFINED_ERR );
503     }
504 
505     point = curr_point;
506 
507 
508     __END__;
509 
510     //icvSubdiv2DCheck( subdiv );
511 
512     return point;
513 }
514 
515 
516 CV_IMPL void
cvInitSubdivDelaunay2D(CvSubdiv2D * subdiv,CvRect rect)517 cvInitSubdivDelaunay2D( CvSubdiv2D * subdiv, CvRect rect )
518 {
519     float big_coord = 3.f * MAX( rect.width, rect.height );
520     CvPoint2D32f ppA, ppB, ppC;
521     CvSubdiv2DPoint *pA, *pB, *pC;
522     CvSubdiv2DEdge edge_AB, edge_BC, edge_CA;
523     float rx = (float) rect.x;
524     float ry = (float) rect.y;
525 
526     CV_FUNCNAME( "cvSubdivDelaunay2DInit" );
527 
528     __BEGIN__;
529 
530     if( !subdiv )
531         CV_ERROR( CV_StsNullPtr, "" );
532 
533     cvClearSet( (CvSet *) (subdiv->edges) );
534     cvClearSet( (CvSet *) subdiv );
535 
536     subdiv->quad_edges = 0;
537     subdiv->recent_edge = 0;
538     subdiv->is_geometry_valid = 0;
539 
540     subdiv->topleft = cvPoint2D32f( rx, ry );
541     subdiv->bottomright = cvPoint2D32f( rx + rect.width, ry + rect.height );
542 
543     ppA = cvPoint2D32f( rx + big_coord, ry );
544     ppB = cvPoint2D32f( rx, ry + big_coord );
545     ppC = cvPoint2D32f( rx - big_coord, ry - big_coord );
546 
547     pA = cvSubdiv2DAddPoint( subdiv, ppA, 0 );
548     pB = cvSubdiv2DAddPoint( subdiv, ppB, 0 );
549     pC = cvSubdiv2DAddPoint( subdiv, ppC, 0 );
550 
551     edge_AB = cvSubdiv2DMakeEdge( subdiv );
552     edge_BC = cvSubdiv2DMakeEdge( subdiv );
553     edge_CA = cvSubdiv2DMakeEdge( subdiv );
554 
555     cvSubdiv2DSetEdgePoints( edge_AB, pA, pB );
556     cvSubdiv2DSetEdgePoints( edge_BC, pB, pC );
557     cvSubdiv2DSetEdgePoints( edge_CA, pC, pA );
558 
559     cvSubdiv2DSplice( edge_AB, cvSubdiv2DSymEdge( edge_CA ));
560     cvSubdiv2DSplice( edge_BC, cvSubdiv2DSymEdge( edge_AB ));
561     cvSubdiv2DSplice( edge_CA, cvSubdiv2DSymEdge( edge_BC ));
562 
563     subdiv->recent_edge = edge_AB;
564 
565 
566     __END__;
567 }
568 
569 
570 CV_IMPL void
cvClearSubdivVoronoi2D(CvSubdiv2D * subdiv)571 cvClearSubdivVoronoi2D( CvSubdiv2D * subdiv )
572 {
573     int elem_size;
574     int i, total;
575     CvSeqReader reader;
576 
577     CV_FUNCNAME( "cvClearVoronoi2D" );
578 
579     __BEGIN__;
580 
581     if( !subdiv )
582         CV_ERROR( CV_StsNullPtr, "" );
583 
584     /* clear pointers to voronoi points */
585     total = subdiv->edges->total;
586     elem_size = subdiv->edges->elem_size;
587 
588     cvStartReadSeq( (CvSeq *) (subdiv->edges), &reader, 0 );
589 
590     for( i = 0; i < total; i++ )
591     {
592         CvQuadEdge2D *quadedge = (CvQuadEdge2D *) reader.ptr;
593 
594         quadedge->pt[1] = quadedge->pt[3] = 0;
595         CV_NEXT_SEQ_ELEM( elem_size, reader );
596     }
597 
598     /* remove voronoi points */
599     total = subdiv->total;
600     elem_size = subdiv->elem_size;
601 
602     cvStartReadSeq( (CvSeq *) subdiv, &reader, 0 );
603 
604     for( i = 0; i < total; i++ )
605     {
606         CvSubdiv2DPoint *pt = (CvSubdiv2DPoint *) reader.ptr;
607 
608         /* check for virtual point. it is also check that the point exists */
609         if( pt->flags & CV_SUBDIV2D_VIRTUAL_POINT_FLAG )
610         {
611             cvSetRemoveByPtr( (CvSet*)subdiv, pt );
612         }
613         CV_NEXT_SEQ_ELEM( elem_size, reader );
614     }
615 
616     subdiv->is_geometry_valid = 0;
617 
618 
619     __END__;
620 }
621 
622 
623 CV_IMPL void
cvCalcSubdivVoronoi2D(CvSubdiv2D * subdiv)624 cvCalcSubdivVoronoi2D( CvSubdiv2D * subdiv )
625 {
626     CvSeqReader reader;
627     int i, total, elem_size;
628 
629     CV_FUNCNAME( "cvCalcSubdivVoronoi2D" );
630 
631     __BEGIN__;
632 
633     if( !subdiv )
634         CV_ERROR( CV_StsNullPtr, "" );
635 
636     /* check if it is already calculated */
637     if( subdiv->is_geometry_valid )
638         EXIT;
639 
640     total = subdiv->edges->total;
641     elem_size = subdiv->edges->elem_size;
642 
643     cvClearSubdivVoronoi2D( subdiv );
644 
645     cvStartReadSeq( (CvSeq *) (subdiv->edges), &reader, 0 );
646 
647     if( total <= 3 )
648         EXIT;
649 
650     /* skip first three edges (bounding triangle) */
651     for( i = 0; i < 3; i++ )
652         CV_NEXT_SEQ_ELEM( elem_size, reader );
653 
654     /* loop through all quad-edges */
655     for( ; i < total; i++ )
656     {
657         CvQuadEdge2D *quadedge = (CvQuadEdge2D *) (reader.ptr);
658 
659         if( CV_IS_SET_ELEM( quadedge ))
660         {
661             CvSubdiv2DEdge edge0 = (CvSubdiv2DEdge) quadedge, edge1, edge2;
662             double a0, b0, c0, a1, b1, c1;
663             CvPoint2D32f virt_point;
664             CvSubdiv2DPoint *voronoi_point;
665 
666             if( !quadedge->pt[3] )
667             {
668                 edge1 = cvSubdiv2DGetEdge( edge0, CV_NEXT_AROUND_LEFT );
669                 edge2 = cvSubdiv2DGetEdge( edge1, CV_NEXT_AROUND_LEFT );
670 
671                 icvCreateCenterNormalLine( edge0, &a0, &b0, &c0 );
672                 icvCreateCenterNormalLine( edge1, &a1, &b1, &c1 );
673 
674                 icvIntersectLines3( &a0, &b0, &c0, &a1, &b1, &c1, &virt_point );
675                 if( fabs( virt_point.x ) < FLT_MAX * 0.5 &&
676                     fabs( virt_point.y ) < FLT_MAX * 0.5 )
677                 {
678                     voronoi_point = cvSubdiv2DAddPoint( subdiv, virt_point, 1 );
679 
680                     quadedge->pt[3] =
681                         ((CvQuadEdge2D *) (edge1 & ~3))->pt[3 - (edge1 & 2)] =
682                         ((CvQuadEdge2D *) (edge2 & ~3))->pt[3 - (edge2 & 2)] = voronoi_point;
683                 }
684             }
685 
686             if( !quadedge->pt[1] )
687             {
688                 edge1 = cvSubdiv2DGetEdge( edge0, CV_NEXT_AROUND_RIGHT );
689                 edge2 = cvSubdiv2DGetEdge( edge1, CV_NEXT_AROUND_RIGHT );
690 
691                 icvCreateCenterNormalLine( edge0, &a0, &b0, &c0 );
692                 icvCreateCenterNormalLine( edge1, &a1, &b1, &c1 );
693 
694                 icvIntersectLines3( &a0, &b0, &c0, &a1, &b1, &c1, &virt_point );
695 
696                 if( fabs( virt_point.x ) < FLT_MAX * 0.5 &&
697                     fabs( virt_point.y ) < FLT_MAX * 0.5 )
698                 {
699                     voronoi_point = cvSubdiv2DAddPoint( subdiv, virt_point, 1 );
700 
701                     quadedge->pt[1] =
702                         ((CvQuadEdge2D *) (edge1 & ~3))->pt[1 + (edge1 & 2)] =
703                         ((CvQuadEdge2D *) (edge2 & ~3))->pt[1 + (edge2 & 2)] = voronoi_point;
704                 }
705             }
706         }
707 
708         CV_NEXT_SEQ_ELEM( elem_size, reader );
709     }
710 
711     subdiv->is_geometry_valid = 1;
712 
713 
714     __END__;
715 }
716 
717 
718 static int
icvIsRightOf2(const CvPoint2D32f & pt,const CvPoint2D32f & org,const CvPoint2D32f & diff)719 icvIsRightOf2( const CvPoint2D32f& pt, const CvPoint2D32f& org, const CvPoint2D32f& diff )
720 {
721     Cv32suf cw_area;
722     cw_area.f = (org.x - pt.x)*diff.y - (org.y - pt.y)*diff.x;
723     return (cw_area.i > 0)*2 - (cw_area.i*2 != 0);
724 }
725 
726 
727 CV_IMPL CvSubdiv2DPoint*
cvFindNearestPoint2D(CvSubdiv2D * subdiv,CvPoint2D32f pt)728 cvFindNearestPoint2D( CvSubdiv2D* subdiv, CvPoint2D32f pt )
729 {
730     CvSubdiv2DPoint* point = 0;
731     CvPoint2D32f start;
732     CvPoint2D32f diff;
733     CvSubdiv2DPointLocation loc;
734     CvSubdiv2DEdge edge;
735     int i;
736 
737     CV_FUNCNAME("cvFindNearestPoint2D");
738 
739     __BEGIN__;
740 
741     if( !subdiv )
742         CV_ERROR( CV_StsNullPtr, "" );
743 
744     if( !CV_IS_SUBDIV2D( subdiv ))
745         CV_ERROR( CV_StsNullPtr, "" );
746 
747     if( !subdiv->is_geometry_valid )
748         cvCalcSubdivVoronoi2D( subdiv );
749 
750     loc = cvSubdiv2DLocate( subdiv, pt, &edge, &point );
751 
752     switch( loc )
753     {
754     case CV_PTLOC_ON_EDGE:
755     case CV_PTLOC_INSIDE:
756         break;
757     default:
758         EXIT;
759     }
760 
761     point = 0;
762 
763     start = cvSubdiv2DEdgeOrg( edge )->pt;
764     diff.x = pt.x - start.x;
765     diff.y = pt.y - start.y;
766 
767     edge = cvSubdiv2DRotateEdge( edge, 1 );
768 
769     for( i = 0; i < subdiv->total; i++ )
770     {
771         CvPoint2D32f t;
772 
773         for(;;)
774         {
775             assert( cvSubdiv2DEdgeDst( edge ));
776 
777             t = cvSubdiv2DEdgeDst( edge )->pt;
778             if( icvIsRightOf2( t, start, diff ) >= 0 )
779                 break;
780 
781             edge = cvSubdiv2DGetEdge( edge, CV_NEXT_AROUND_LEFT );
782         }
783 
784         for(;;)
785         {
786             assert( cvSubdiv2DEdgeOrg( edge ));
787 
788             t = cvSubdiv2DEdgeOrg( edge )->pt;
789             if( icvIsRightOf2( t, start, diff ) < 0 )
790                 break;
791 
792             edge = cvSubdiv2DGetEdge( edge, CV_PREV_AROUND_LEFT );
793         }
794 
795         {
796             CvPoint2D32f tempDiff = cvSubdiv2DEdgeDst( edge )->pt;
797             t = cvSubdiv2DEdgeOrg( edge )->pt;
798             tempDiff.x -= t.x;
799             tempDiff.y -= t.y;
800 
801             if( icvIsRightOf2( pt, t, tempDiff ) >= 0 )
802             {
803                 point = cvSubdiv2DEdgeOrg( cvSubdiv2DRotateEdge( edge, 3 ));
804                 break;
805             }
806         }
807 
808         edge = cvSubdiv2DSymEdge( edge );
809     }
810 
811     __END__;
812 
813     return point;
814 }
815 
816 /* Removed from the main interface */
817 
818 #if 0
819 /* Adds new isolated quadedge to the subdivision */
820 OPENCVAPI  CvSubdiv2DEdge  cvSubdiv2DMakeEdge( CvSubdiv2D* subdiv );
821 
822 
823 /* Adds new isolated point to subdivision */
824 OPENCVAPI  CvSubdiv2DPoint*   cvSubdiv2DAddPoint( CvSubdiv2D* subdiv,
825                                                   CvPoint2D32f pt, int is_virtual );
826 
827 
828 /* Does a splice operation for two quadedges */
829 OPENCVAPI  void  cvSubdiv2DSplice( CvSubdiv2DEdge  edgeA,  CvSubdiv2DEdge  edgeB );
830 
831 
832 /* Assigns ending [non-virtual] points for given quadedge */
833 OPENCVAPI  void  cvSubdiv2DSetEdgePoints( CvSubdiv2DEdge edge,
834                                           CvSubdiv2DPoint* org_pt,
835                                           CvSubdiv2DPoint* dst_pt );
836 
837 /* Removes quadedge from subdivision */
838 OPENCVAPI  void  cvSubdiv2DDeleteEdge( CvSubdiv2D* subdiv, CvSubdiv2DEdge edge );
839 
840 
841 /* Connects estination point of the first edge with origin point of the second edge */
842 OPENCVAPI  CvSubdiv2DEdge  cvSubdiv2DConnectEdges( CvSubdiv2D* subdiv,
843                                                    CvSubdiv2DEdge edgeA,
844                                                    CvSubdiv2DEdge edgeB );
845 
846 /* Swaps diagonal in two connected Delaunay facets */
847 OPENCVAPI  void  cvSubdiv2DSwapEdges( CvSubdiv2DEdge edge );
848 #endif
849 
850 /* End of file. */
851