summaryrefslogtreecommitdiff
path: root/inc/Geom_BSplineCurve.hxx
blob: 0607b4729f6edc0d0b2e2a2afb4e62603e1ca9db (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
// This file is generated by WOK (CPPExt).
// Please do not edit this file; modify original file instead.
// The copyright and license terms as defined for the original file apply to 
// this header file considered to be the "object code" form of the original source.

#ifndef _Geom_BSplineCurve_HeaderFile
#define _Geom_BSplineCurve_HeaderFile

#ifndef _Standard_HeaderFile
#include <Standard.hxx>
#endif
#ifndef _Standard_DefineHandle_HeaderFile
#include <Standard_DefineHandle.hxx>
#endif
#ifndef _Handle_Geom_BSplineCurve_HeaderFile
#include <Handle_Geom_BSplineCurve.hxx>
#endif

#ifndef _Standard_Boolean_HeaderFile
#include <Standard_Boolean.hxx>
#endif
#ifndef _GeomAbs_BSplKnotDistribution_HeaderFile
#include <GeomAbs_BSplKnotDistribution.hxx>
#endif
#ifndef _GeomAbs_Shape_HeaderFile
#include <GeomAbs_Shape.hxx>
#endif
#ifndef _Standard_Integer_HeaderFile
#include <Standard_Integer.hxx>
#endif
#ifndef _Handle_TColgp_HArray1OfPnt_HeaderFile
#include <Handle_TColgp_HArray1OfPnt.hxx>
#endif
#ifndef _Handle_TColStd_HArray1OfReal_HeaderFile
#include <Handle_TColStd_HArray1OfReal.hxx>
#endif
#ifndef _Handle_TColStd_HArray1OfInteger_HeaderFile
#include <Handle_TColStd_HArray1OfInteger.hxx>
#endif
#ifndef _Standard_Real_HeaderFile
#include <Standard_Real.hxx>
#endif
#ifndef _Geom_BoundedCurve_HeaderFile
#include <Geom_BoundedCurve.hxx>
#endif
#ifndef _Handle_Geom_Geometry_HeaderFile
#include <Handle_Geom_Geometry.hxx>
#endif
class TColgp_HArray1OfPnt;
class TColStd_HArray1OfReal;
class TColStd_HArray1OfInteger;
class Standard_ConstructionError;
class Standard_DimensionError;
class Standard_DomainError;
class Standard_OutOfRange;
class Standard_RangeError;
class Standard_NoSuchObject;
class Geom_UndefinedDerivative;
class TColgp_Array1OfPnt;
class TColStd_Array1OfReal;
class TColStd_Array1OfInteger;
class gp_Pnt;
class gp_Vec;
class gp_Trsf;
class Geom_Geometry;


//! Definition of the B_spline curve. <br>
//!       A B-spline curve can be <br>
//!         Uniform  or non-uniform <br>
//!         Rational or non-rational <br>
//!         Periodic or non-periodic <br>
//! <br>
//!  a b-spline curve is defined by : <br>
//!  its degree; the degree for a <br>
//!   Geom_BSplineCurve is limited to a value (25) <br>
//!   which is defined and controlled by the system. <br>
//!   This value is returned by the function MaxDegree; <br>
//! - its periodic or non-periodic nature; <br>
//! - a table of poles (also called control points), with <br>
//!   their associated weights if the BSpline curve is <br>
//!   rational. The poles of the curve are "control <br>
//!   points" used to deform the curve. If the curve is <br>
//!   non-periodic, the first pole is the start point of <br>
//!   the curve, and the last pole is the end point of <br>
//!   the curve. The segment which joins the first pole <br>
//!   to the second pole is the tangent to the curve at <br>
//!   its start point, and the segment which joins the <br>
//!   last pole to the second-from-last pole is the <br>
//!   tangent to the curve at its end point. If the curve <br>
//!   is periodic, these geometric properties are not <br>
//!   verified. It is more difficult to give a geometric <br>
//!   signification to the weights but are useful for <br>
//!   providing exact representations of the arcs of a <br>
//!   circle or ellipse. Moreover, if the weights of all the <br>
//!   poles are equal, the curve has a polynomial <br>
//!   equation; it is therefore a non-rational curve. <br>
//! - a table of knots with their multiplicities. For a <br>
//!   Geom_BSplineCurve, the table of knots is an <br>
//!   increasing sequence of reals without repetition; <br>
//!   the multiplicities define the repetition of the knots. <br>
//!   A BSpline curve is a piecewise polynomial or <br>
//!   rational curve. The knots are the parameters of <br>
//!   junction points between two pieces. The <br>
//!   multiplicity Mult(i) of the knot Knot(i) of <br>
//!   the BSpline curve is related to the degree of <br>
//!   continuity of the curve at the knot Knot(i), <br>
//!   which is equal to Degree - Mult(i) <br>
//!   where Degree is the degree of the BSpline curve. <br>
//!   If the knots are regularly spaced (i.e. the difference <br>
//!   between two consecutive knots is a constant), three <br>
//!   specific and frequently used cases of knot <br>
//!   distribution can be identified: <br>
//! - "uniform" if all multiplicities are equal to 1, <br>
//! - "quasi-uniform" if all multiplicities are equal to 1, <br>
//!   except the first and the last knot which have a <br>
//!   multiplicity of Degree + 1, where Degree is <br>
//!   the degree of the BSpline curve, <br>
//! - "Piecewise Bezier" if all multiplicities are equal to <br>
//!   Degree except the first and last knot which <br>
//!   have a multiplicity of Degree + 1, where <br>
//!   Degree is the degree of the BSpline curve. A <br>
//!   curve of this type is a concatenation of arcs of Bezier curves. <br>
//! If the BSpline curve is not periodic: <br>
//! - the bounds of the Poles and Weights tables are 1 <br>
//!   and NbPoles, where NbPoles is the number <br>
//!   of poles of the BSpline curve, <br>
//! - the bounds of the Knots and Multiplicities tables <br>
//!   are 1 and NbKnots, where NbKnots is the <br>
//!   number of knots of the BSpline curve. <br>
//! If the BSpline curve is periodic, and if there are k <br>
//! periodic knots and p periodic poles, the period is: <br>
//! period = Knot(k + 1) - Knot(1) <br>
//! and the poles and knots tables can be considered <br>
//! as infinite tables, verifying: <br>
//! - Knot(i+k) = Knot(i) + period <br>
//! - Pole(i+p) = Pole(i) <br>
//! Note: data structures of a periodic BSpline curve <br>
//! are more complex than those of a non-periodic one. <br>
//! Warning <br>
//! In this class, weight value is considered to be zero if <br>
//! the weight is less than or equal to gp::Resolution(). <br>
//! <br>
//! References : <br>
//!  . A survey of curve and surface methods in CADG Wolfgang BOHM <br>
//!    CAGD 1 (1984) <br>
//!  . On de Boor-like algorithms and blossoming Wolfgang BOEHM <br>
//!    cagd 5 (1988) <br>
//!  . Blossoming and knot insertion algorithms for B-spline curves <br>
//!    Ronald N. GOLDMAN <br>
//!  . Modelisation des surfaces en CAO, Henri GIAUME Peugeot SA <br>
//!  . Curves and Surfaces for Computer Aided Geometric Design, <br>
//!    a practical guide Gerald Farin <br>
class Geom_BSplineCurve : public Geom_BoundedCurve {

public:

  //!  Creates a  non-rational B_spline curve   on  the <br>
//!         basis <Knots, Multiplicities> of degree <Degree>. <br>
  Standard_EXPORT   Geom_BSplineCurve(const TColgp_Array1OfPnt& Poles,const TColStd_Array1OfReal& Knots,const TColStd_Array1OfInteger& Multiplicities,const Standard_Integer Degree,const Standard_Boolean Periodic = Standard_False);
  //! Creates  a rational B_spline  curve  on the basis <br>
//!         <Knots, Multiplicities> of degree <Degree>. <br>
//!  Raises ConstructionError subject to the following conditions <br>
//!  0 < Degree <= MaxDegree. <br>
//! <br>
//!  Weights.Length() == Poles.Length() <br>
//! <br>
//!  Knots.Length() == Mults.Length() >= 2 <br>
//! <br>
//!  Knots(i) < Knots(i+1) (Knots are increasing) <br>
//! <br>
//!  1 <= Mults(i) <= Degree <br>
//! <br>
//!   On a non periodic curve the first and last multiplicities <br>
//!   may be Degree+1 (this is even recommanded if you want the <br>
//!   curve to start and finish on the first and last pole). <br>
//! <br>
//!   On a periodic  curve the first  and  the last multicities <br>
//!   must be the same. <br>
//! <br>
//!   on non-periodic curves <br>
//! <br>
//!     Poles.Length() == Sum(Mults(i)) - Degree - 1 >= 2 <br>
//! <br>
//!   on periodic curves <br>
//! <br>
//!     Poles.Length() == Sum(Mults(i)) except the first or last <br>
  Standard_EXPORT   Geom_BSplineCurve(const TColgp_Array1OfPnt& Poles,const TColStd_Array1OfReal& Weights,const TColStd_Array1OfReal& Knots,const TColStd_Array1OfInteger& Multiplicities,const Standard_Integer Degree,const Standard_Boolean Periodic = Standard_False,const Standard_Boolean CheckRational = Standard_True);
  //! Increases the degree of this BSpline curve to <br>
//! Degree. As a result, the poles, weights and <br>
//! multiplicities tables are modified; the knots table is <br>
//! not changed. Nothing is done if Degree is less than <br>
//! or equal to the current degree. <br>
//! Exceptions <br>
//! Standard_ConstructionError if Degree is greater than <br>
//! Geom_BSplineCurve::MaxDegree(). <br>
  Standard_EXPORT     void IncreaseDegree(const Standard_Integer Degree) ;
  //!Increases the multiplicity  of the knot <Index> to <br>
//!         <M>. <br>
//! <br>
//!         If   <M>   is   lower   or  equal   to  the current <br>
//!         multiplicity nothing is done. If <M> is higher than <br>
//!         the degree the degree is used. <br>//! If <Index> is not in [FirstUKnotIndex, LastUKnotIndex] <br>
  Standard_EXPORT     void IncreaseMultiplicity(const Standard_Integer Index,const Standard_Integer M) ;
  //!Increases  the  multiplicities   of  the knots  in <br>
//!         [I1,I2] to <M>. <br>
//! <br>
//!         For each knot if  <M>  is  lower  or equal  to  the <br>
//!         current multiplicity  nothing  is  done. If <M>  is <br>
//!         higher than the degree the degree is used. <br>//! If <I1,I2> are not in [FirstUKnotIndex, LastUKnotIndex] <br>
  Standard_EXPORT     void IncreaseMultiplicity(const Standard_Integer I1,const Standard_Integer I2,const Standard_Integer M) ;
  //!Increment  the  multiplicities   of  the knots  in <br>
//!         [I1,I2] by <M>. <br>
//! <br>
//!         If <M> is not positive nithing is done. <br>
//! <br>
//!         For   each  knot   the resulting   multiplicity  is <br>
//!         limited to the Degree. <br>//! If <I1,I2> are not in [FirstUKnotIndex, LastUKnotIndex] <br>
  Standard_EXPORT     void IncrementMultiplicity(const Standard_Integer I1,const Standard_Integer I2,const Standard_Integer M) ;
  //! Inserts a knot value in the sequence of knots.  If <br>
//!          <U>  is an  existing knot     the multiplicity  is <br>
//!          increased by <M>. <br>
//! <br>
//!          If U  is  not  on the parameter  range  nothing is <br>
//!          done. <br>
//! <br>
//!          If the multiplicity is negative or null nothing is <br>
//!          done. The  new   multiplicity  is limited  to  the <br>
//!          degree. <br>
//! <br>
//!          The  tolerance criterion  for  knots  equality  is <br>
//!          the max of Epsilon(U) and ParametricTolerance. <br>
  Standard_EXPORT     void InsertKnot(const Standard_Real U,const Standard_Integer M = 1,const Standard_Real ParametricTolerance = 0.0,const Standard_Boolean Add = Standard_True) ;
  //! Inserts a set of knots  values in  the sequence of <br>
//!          knots. <br>
//! <br>
//!          For each U = Knots(i), M = Mults(i) <br>
//! <br>
//!          If <U>  is an existing  knot  the  multiplicity is <br>
//!          increased by  <M> if  <Add>  is True, increased to <br>
//!          <M> if <Add> is False. <br>
//! <br>
//!          If U  is  not  on the parameter  range  nothing is <br>
//!          done. <br>
//! <br>
//!          If the multiplicity is negative or null nothing is <br>
//!          done. The  new   multiplicity  is limited  to  the <br>
//!          degree. <br>
//! <br>
//!          The  tolerance criterion  for  knots  equality  is <br>
//!          the max of Epsilon(U) and ParametricTolerance. <br>
  Standard_EXPORT     void InsertKnots(const TColStd_Array1OfReal& Knots,const TColStd_Array1OfInteger& Mults,const Standard_Real ParametricTolerance = 0.0,const Standard_Boolean Add = Standard_False) ;
  //! Reduces the multiplicity of the knot of index Index <br>
//! to M. If M is equal to 0, the knot is removed. <br>
//! With a modification of this type, the array of poles is also modified. <br>
//! Two different algorithms are systematically used to <br>
//! compute the new poles of the curve. If, for each <br>
//! pole, the distance between the pole calculated <br>
//! using the first algorithm and the same pole <br>
//! calculated using the second algorithm, is less than <br>
//! Tolerance, this ensures that the curve is not <br>
//! modified by more than Tolerance. Under these <br>
//! conditions, true is returned; otherwise, false is returned. <br>
//! A low tolerance is used to prevent modification of <br>
//! the curve. A high tolerance is used to "smooth" the curve. <br>
//! Exceptions <br>
//! Standard_OutOfRange if Index is outside the <br>
//! bounds of the knots table. <br>//! pole insertion and pole removing <br>
//!  this operation is limited to the Uniform or QuasiUniform <br>
//!  BSplineCurve. The knot values are modified . If the BSpline is <br>
//!  NonUniform or Piecewise Bezier an exception Construction error <br>
//!  is raised. <br>
  Standard_EXPORT     Standard_Boolean RemoveKnot(const Standard_Integer Index,const Standard_Integer M,const Standard_Real Tolerance) ;
  
//!  Changes the direction of parametrization of <me>. The Knot <br>
//!  sequence is modified, the FirstParameter and the <br>
//!  LastParameter are not modified. The StartPoint of the <br>
//!  initial curve becomes the EndPoint of the reversed curve <br>
//!  and the EndPoint of the initial curve becomes the StartPoint <br>
//!  of the reversed curve. <br>
  Standard_EXPORT     void Reverse() ;
  //! Returns the  parameter on the  reversed  curve for <br>
//!          the point of parameter U on <me>. <br>
//! <br>
//!          returns UFirst + ULast - U <br>
  Standard_EXPORT     Standard_Real ReversedParameter(const Standard_Real U) const;
  //! Modifies this BSpline curve by segmenting it between <br>
//! U1 and U2. Either of these values can be outside the <br>
//! bounds of the curve, but U2 must be greater than U1. <br>
//! All data structure tables of this BSpline curve are <br>
//! modified, but the knots located between U1 and U2 <br>
//! are retained. The degree of the curve is not modified. <br>
//!  Warnings : <br>
//!  Even if <me> is not closed it can become closed after the <br>
//!  segmentation for example if U1 or U2 are out of the bounds <br>
//!  of the curve <me> or if the curve makes loop. <br>
//!  After the segmentation the length of a curve can be null. <br>//! raises if U2 < U1. <br>
  Standard_EXPORT     void Segment(const Standard_Real U1,const Standard_Real U2) ;
  //! Modifies this BSpline curve by assigning the value K <br>
//! to the knot of index Index in the knots table. This is a <br>
//! relatively local modification because K must be such that: <br>
//! Knots(Index - 1) < K < Knots(Index + 1) <br>
//! The second syntax allows you also to increase the <br>
//! multiplicity of the knot to M (but it is not possible to <br>
//! decrease the multiplicity of the knot with this function). <br>
//! Standard_ConstructionError if: <br>
//! - K is not such that: <br>
//! Knots(Index - 1) < K < Knots(Index + 1) <br>
//! - M is greater than the degree of this BSpline curve <br>
//!   or lower than the previous multiplicity of knot of <br>
//!   index Index in the knots table. <br>
//!  Standard_OutOfRange if Index is outside the bounds of the knots table. <br>
  Standard_EXPORT     void SetKnot(const Standard_Integer Index,const Standard_Real K) ;
  //!  Modifies this BSpline curve by assigning the array <br>
//! K to its knots table. The multiplicity of the knots is not modified. <br>
//! Exceptions <br>
//! Standard_ConstructionError if the values in the <br>
//! array K are not in ascending order. <br>
//! Standard_OutOfRange if the bounds of the array <br>
//! K are not respectively 1 and the number of knots of this BSpline curve. <br>
  Standard_EXPORT     void SetKnots(const TColStd_Array1OfReal& K) ;
  
//!  Changes the knot of range Index with its multiplicity. <br>
//!  You can increase the multiplicity of a knot but it is <br>
//!  not allowed to decrease the multiplicity of an existing knot. <br>
//!  Raised if K >= Knots(Index+1) or K <= Knots(Index-1). <br>
//!  Raised if M is greater than Degree or lower than the previous <br>
//!  multiplicity of knot of range Index. <br>//! Raised if Index < 1 || Index > NbKnots <br>
  Standard_EXPORT     void SetKnot(const Standard_Integer Index,const Standard_Real K,const Standard_Integer M) ;
  //! returns the parameter normalized within <br>
//!         the period if the curve is periodic : otherwise <br>
//!         does not do anything <br>
  Standard_EXPORT     void PeriodicNormalization(Standard_Real& U) const;
  //! Changes this BSpline curve into a periodic curve. <br>
//! To become periodic, the curve must first be closed. <br>
//! Next, the knot sequence must be periodic. For this, <br>
//! FirstUKnotIndex and LastUKnotIndex are used <br>
//! to compute I1 and I2, the indexes in the knots <br>
//! array of the knots corresponding to the first and <br>
//! last parameters of this BSpline curve. <br>
//! The period is therefore: Knots(I2) - Knots(I1). <br>
//! Consequently, the knots and poles tables are modified. <br>
//! Exceptions <br>
//! Standard_ConstructionError if this BSpline curve is not closed. <br>
  Standard_EXPORT     void SetPeriodic() ;
  //! Assigns the knot of index Index in the knots table as <br>
//! the origin of this periodic BSpline curve. As a <br>
//! consequence, the knots and poles tables are modified. <br>
//! Exceptions <br>
//! Standard_NoSuchObject if this curve is not periodic. <br>
//! Standard_DomainError if Index is outside the bounds of the knots table. <br>
  Standard_EXPORT     void SetOrigin(const Standard_Integer Index) ;
  //! Set the origin of a periodic curve at Knot U. If U <br>
//!          is  not a  knot  of  the  BSpline  a  new knot  is <br>
//!          inseted. KnotVector and poles are modified. <br>//! Raised if the curve is not periodic <br>
  Standard_EXPORT     void SetOrigin(const Standard_Real U,const Standard_Real Tol) ;
  //! Changes this BSpline curve into a non-periodic <br>
//! curve. If this curve is already non-periodic, it is not modified. <br>
//! Note: the poles and knots tables are modified. <br>
//! Warning <br>
//! If this curve is periodic, as the multiplicity of the first <br>
//! and last knots is not modified, and is not equal to <br>
//! Degree + 1, where Degree is the degree of <br>
//! this BSpline curve, the start and end points of the <br>
//! curve are not its first and last poles. <br>
  Standard_EXPORT     void SetNotPeriodic() ;
  //! Modifies this BSpline curve by assigning P to the pole <br>
//! of index Index in the poles table. <br>
//! Exceptions <br>
//! Standard_OutOfRange if Index is outside the <br>
//! bounds of the poles table. <br>
//! Standard_ConstructionError if Weight is negative or null. <br>
  Standard_EXPORT     void SetPole(const Standard_Integer Index,const gp_Pnt& P) ;
  //! Modifies this BSpline curve by assigning P to the pole <br>
//! of index Index in the poles table. <br>
//! This syntax also allows you to modify the <br>
//! weight of the modified pole, which becomes Weight. <br>
//! In this case, if this BSpline curve is non-rational, it <br>
//! can become rational and vice versa. <br>
//! Exceptions <br>
//! Standard_OutOfRange if Index is outside the <br>
//! bounds of the poles table. <br>
//! Standard_ConstructionError if Weight is negative or null. <br>
  Standard_EXPORT     void SetPole(const Standard_Integer Index,const gp_Pnt& P,const Standard_Real Weight) ;
  
//!  Changes the weight for the pole of range Index. <br>
//!  If the curve was non rational it can become rational. <br>
//!  If the curve was rational it can become non rational. <br>
//!  Raised if Index < 1 || Index > NbPoles <br>//! Raised if Weight <= 0.0 <br>
  Standard_EXPORT     void SetWeight(const Standard_Integer Index,const Standard_Real Weight) ;
  //! Moves the point of parameter U of this BSpline curve <br>
//! to P. Index1 and Index2 are the indexes in the table <br>
//! of poles of this BSpline curve of the first and last <br>
//! poles designated to be moved. <br>
//! FirstModifiedPole and LastModifiedPole are the <br>
//! indexes of the first and last poles which are effectively modified. <br>
//! In the event of incompatibility between Index1, Index2 and the value U: <br>
//! - no change is made to this BSpline curve, and <br>
//! - the FirstModifiedPole and LastModifiedPole are returned null. <br>
//!   Exceptions <br>
//! Standard_OutOfRange if: <br>
//! - Index1 is greater than or equal to Index2, or <br>
//! - Index1 or Index2 is less than 1 or greater than the <br>
//!   number of poles of this BSpline curve. <br>
  Standard_EXPORT     void MovePoint(const Standard_Real U,const gp_Pnt& P,const Standard_Integer Index1,const Standard_Integer Index2,Standard_Integer& FirstModifiedPole,Standard_Integer& LastModifiedPole) ;
  
//! Move a point with parameter U to P. <br>
//! and makes it tangent at U be Tangent. <br>
//! StartingCondition = -1 means first can move <br>
//! EndingCondition   = -1 means last point can move <br>
//! StartingCondition = 0 means the first point cannot move <br>
//! EndingCondition   = 0 means the last point cannot move <br>
//! StartingCondition = 1 means the first point and tangent cannot move <br>
//! EndingCondition   = 1 means the last point and tangent cannot move <br>
//! and so forth <br>
//! ErrorStatus != 0 means that there are not enought degree of freedom <br>
//! with the constrain to deform the curve accordingly <br>
//! <br>
  Standard_EXPORT     void MovePointAndTangent(const Standard_Real U,const gp_Pnt& P,const gp_Vec& Tangent,const Standard_Real Tolerance,const Standard_Integer StartingCondition,const Standard_Integer EndingCondition,Standard_Integer& ErrorStatus) ;
  
//!  Returns the continuity of the curve, the curve is at least C0. <br>//! Raised if N < 0. <br>
  Standard_EXPORT     Standard_Boolean IsCN(const Standard_Integer N) const;
  
//!  Returns true if the distance between the first point and the <br>
//!  last point of the curve is lower or equal to Resolution <br>
//!  from package gp. <br>
//! Warnings : <br>
//!  The first and the last point can be different from the first <br>
//!  pole and the last pole of the curve. <br>
  Standard_EXPORT     Standard_Boolean IsClosed() const;
  //! Returns True if the curve is periodic. <br>
  Standard_EXPORT     Standard_Boolean IsPeriodic() const;
  
//!  Returns True if the weights are not identical. <br>
//!  The tolerance criterion is Epsilon of the class Real. <br>
  Standard_EXPORT     Standard_Boolean IsRational() const;
  
//!  Returns the global continuity of the curve : <br>
//!  C0 : only geometric continuity, <br>
//!  C1 : continuity of the first derivative all along the Curve, <br>
//!  C2 : continuity of the second derivative all along the Curve, <br>
//!  C3 : continuity of the third derivative all along the Curve, <br>
//!  CN : the order of continuity is infinite. <br>
//!  For a B-spline curve of degree d if a knot Ui has a <br>
//!  multiplicity p the B-spline curve is only Cd-p continuous <br>
//!  at Ui. So the global continuity of the curve can't be greater <br>
//!  than Cd-p where p is the maximum multiplicity of the interior <br>
//!  Knots. In the interior of a knot span the curve is infinitely <br>
//!  continuously differentiable. <br>
  Standard_EXPORT     GeomAbs_Shape Continuity() const;
  //! Returns the degree of this BSpline curve. <br>
//! The degree of a Geom_BSplineCurve curve cannot <br>
//! be greater than Geom_BSplineCurve::MaxDegree(). <br>//! Computation of value and derivatives <br>
  Standard_EXPORT     Standard_Integer Degree() const;
  //! Returns in P the point of parameter U. <br>
  Standard_EXPORT     void D0(const Standard_Real U,gp_Pnt& P) const;
  //! Raised if the continuity of the curve is not C1. <br>
  Standard_EXPORT     void D1(const Standard_Real U,gp_Pnt& P,gp_Vec& V1) const;
  //! Raised if the continuity of the curve is not C2. <br>
  Standard_EXPORT     void D2(const Standard_Real U,gp_Pnt& P,gp_Vec& V1,gp_Vec& V2) const;
  //! Raised if the continuity of the curve is not C3. <br>
  Standard_EXPORT     void D3(const Standard_Real U,gp_Pnt& P,gp_Vec& V1,gp_Vec& V2,gp_Vec& V3) const;
  //! For the point of parameter U of this BSpline curve, <br>
//! computes the vector corresponding to the Nth derivative. <br>
//! Warning <br>
//! On a point where the continuity of the curve is not the <br>
//! one requested, this function impacts the part defined <br>
//! by the parameter with a value greater than U, i.e. the <br>
//! part of the curve to the "right" of the singularity. <br>
//! Exceptions <br>
//! Standard_RangeError if N is less than 1. <br>
//!  The following functions compute the point of parameter U <br>
//!  and the derivatives at this point on the B-spline curve <br>
//!  arc defined between the knot FromK1 and the knot ToK2. <br>
//!  U can be out of bounds [Knot (FromK1),  Knot (ToK2)] but <br>
//!  for the computation we only use the definition of the curve <br>
//!  between these two knots. This method is useful to compute <br>
//!  local derivative, if the order of continuity of the whole <br>
//!  curve is not greater enough.    Inside the parametric <br>
//!  domain Knot (FromK1), Knot (ToK2) the evaluations are <br>
//!  the same as if we consider the whole definition of the <br>
//!  curve. Of course the evaluations are different outside <br>
//!  this parametric domain. <br>
  Standard_EXPORT     gp_Vec DN(const Standard_Real U,const Standard_Integer N) const;
  //! Raised if FromK1 = ToK2. <br>
//!  Raised if FromK1 and ToK2 are not in the range <br>
//!  [FirstUKnotIndex, LastUKnotIndex]. <br>
  Standard_EXPORT     gp_Pnt LocalValue(const Standard_Real U,const Standard_Integer FromK1,const Standard_Integer ToK2) const;
  //! Raised if FromK1 = ToK2. <br>
//!  Raised if FromK1 and ToK2 are not in the range <br>
//!  [FirstUKnotIndex, LastUKnotIndex]. <br>
  Standard_EXPORT     void LocalD0(const Standard_Real U,const Standard_Integer FromK1,const Standard_Integer ToK2,gp_Pnt& P) const;
  
//!  Raised if the local continuity of the curve is not C1 <br>
//!  between the knot K1 and the knot K2. <br>//! Raised if FromK1 = ToK2. <br>
//!  Raised if FromK1 and ToK2 are not in the range <br>
//!  [FirstUKnotIndex, LastUKnotIndex]. <br>
  Standard_EXPORT     void LocalD1(const Standard_Real U,const Standard_Integer FromK1,const Standard_Integer ToK2,gp_Pnt& P,gp_Vec& V1) const;
  
//!  Raised if the local continuity of the curve is not C2 <br>
//!  between the knot K1 and the knot K2. <br>//! Raised if FromK1 = ToK2. <br>
//!  Raised if FromK1 and ToK2 are not in the range <br>
//!  [FirstUKnotIndex, LastUKnotIndex]. <br>
  Standard_EXPORT     void LocalD2(const Standard_Real U,const Standard_Integer FromK1,const Standard_Integer ToK2,gp_Pnt& P,gp_Vec& V1,gp_Vec& V2) const;
  
//!  Raised if the local continuity of the curve is not C3 <br>
//!  between the knot K1 and the knot K2. <br>//! Raised if FromK1 = ToK2. <br>
//!  Raised if FromK1 and ToK2 are not in the range <br>
//!  [FirstUKnotIndex, LastUKnotIndex]. <br>
  Standard_EXPORT     void LocalD3(const Standard_Real U,const Standard_Integer FromK1,const Standard_Integer ToK2,gp_Pnt& P,gp_Vec& V1,gp_Vec& V2,gp_Vec& V3) const;
  
//!  Raised if the local continuity of the curve is not CN <br>
//!  between the knot K1 and the knot K2. <br>//! Raised if FromK1 = ToK2. <br>//! Raised if N < 1. <br>
//!  Raises if FromK1 and ToK2 are not in the range <br>
//!  [FirstUKnotIndex, LastUKnotIndex]. <br>
  Standard_EXPORT     gp_Vec LocalDN(const Standard_Real U,const Standard_Integer FromK1,const Standard_Integer ToK2,const Standard_Integer N) const;
  
//!  Returns the last point of the curve. <br>
//! Warnings : <br>
//!  The last point of the curve is different from the last <br>
//!  pole of the curve if the multiplicity of the last knot <br>
//!  is lower than Degree. <br>
  Standard_EXPORT     gp_Pnt EndPoint() const;
  //! Returns the index in the knot array of the knot <br>
//! corresponding to the first or last parameter of this BSpline curve. <br>
//! For a BSpline curve, the first (or last) parameter <br>
//! (which gives the start (or end) point of the curve) is a <br>
//! knot value. However, if the multiplicity of the first (or <br>
//! last) knot is less than Degree + 1, where <br>
//! Degree is the degree of the curve, it is not the first <br>
//! (or last) knot of the curve. <br>
  Standard_EXPORT     Standard_Integer FirstUKnotIndex() const;
  //! Returns the value of the first parameter of this <br>
//! BSpline curve. This is a knot value. <br>
//! The first parameter is the one of the start point of the BSpline curve. <br>
  Standard_EXPORT     Standard_Real FirstParameter() const;
  
//!  Returns the knot of range Index. When there is a knot <br>
//!  with a multiplicity greater than 1 the knot is not repeated. <br>
//!  The method Multiplicity can be used to get the multiplicity <br>
//!  of the Knot. <br>//! Raised if Index < 1 or Index > NbKnots <br>
  Standard_EXPORT     Standard_Real Knot(const Standard_Integer Index) const;
  //! returns the knot values of the B-spline curve; <br>
//! Warning <br>
//! A knot with a multiplicity greater than 1 is not <br>
//! repeated in the knot table. The Multiplicity function <br>
//! can be used to obtain the multiplicity of each knot. <br>
//!  Raised if the length of K is not equal to the number of knots. <br>
  Standard_EXPORT     void Knots(TColStd_Array1OfReal& K) const;
  //! Returns K, the knots sequence of this BSpline curve. <br>
//! In this sequence, knots with a multiplicity greater than 1 are repeated. <br>
//! In the case of a non-periodic curve the length of the <br>
//! sequence must be equal to the sum of the NbKnots <br>
//! multiplicities of the knots of the curve (where <br>
//! NbKnots is the number of knots of this BSpline <br>
//! curve). This sum is also equal to : NbPoles + Degree + 1 <br>
//! where NbPoles is the number of poles and <br>
//! Degree the degree of this BSpline curve. <br>
//! In the case of a periodic curve, if there are k periodic <br>
//! knots, the period is Knot(k+1) - Knot(1). <br>
//! The initial sequence is built by writing knots 1 to k+1, <br>
//! which are repeated according to their corresponding multiplicities. <br>
//! If Degree is the degree of the curve, the degree of <br>
//! continuity of the curve at the knot of index 1 (or k+1) <br>
//! is equal to c = Degree + 1 - Mult(1). c <br>
//! knots are then inserted at the beginning and end of <br>
//! the initial sequence: <br>
//! - the c values of knots preceding the first item <br>
//!   Knot(k+1) in the initial sequence are inserted <br>
//!   at the beginning; the period is subtracted from these c values; <br>
//! - the c values of knots following the last item <br>
//!   Knot(1) in the initial sequence are inserted at <br>
//!   the end; the period is added to these c values. <br>
//! The length of the sequence must therefore be equal to: <br>
//! NbPoles + 2*Degree - Mult(1) + 2. <br>
//! Example <br>
//! For a non-periodic BSpline curve of degree 2 where: <br>
//! - the array of knots is: { k1 k2 k3 k4 }, <br>
//! - with associated multiplicities: { 3 1 2 3 }, <br>
//! the knot sequence is: <br>
//! K = { k1 k1 k1 k2 k3 k3 k4 k4 k4 } <br>
//! For a periodic BSpline curve of degree 4 , which is <br>
//! "C1" continuous at the first knot, and where : <br>
//! - the periodic knots are: { k1 k2 k3 (k4) } <br>
//!   (3 periodic knots: the points of parameter k1 and k4 <br>
//!   are identical, the period is p = k4 - k1), <br>
//! - with associated multiplicities: { 3 1 2 (3) }, <br>
//! the degree of continuity at knots k1 and k4 is: <br>
//! Degree + 1 - Mult(i) = 2. <br>
//! 2 supplementary knots are added at the beginning <br>
//! and end of the sequence: <br>
//! - at the beginning: the 2 knots preceding k4 minus <br>
//!   the period; in this example, this is k3 - p both times; <br>
//! - at the end: the 2 knots following k1 plus the period; <br>
//!   in this example, this is k2 + p and k3 + p. <br>
//! The knot sequence is therefore: <br>
//! K = { k3-p k3-p k1 k1 k1 k2 k3 k3 <br>
//! k4 k4 k4 k2+p k3+p } <br>
//! Exceptions <br>
//! Standard_DimensionError if the array K is not of <br>
//! the appropriate length.Returns the knots sequence. <br>
  Standard_EXPORT     void KnotSequence(TColStd_Array1OfReal& K) const;
  
//!  Returns NonUniform or Uniform or QuasiUniform or PiecewiseBezier. <br>
//!  If all the knots differ by a positive constant from the <br>
//!  preceding knot the BSpline Curve can be : <br>
//!  - Uniform if all the knots are of multiplicity 1, <br>
//!  - QuasiUniform if all the knots are of multiplicity 1 except for <br>
//!    the first and last knot which are of multiplicity Degree + 1, <br>
//!  - PiecewiseBezier if the first and last knots have multiplicity <br>
//!    Degree + 1 and if interior knots have multiplicity Degree <br>
//!    A piecewise Bezier with only two knots is a BezierCurve. <br>
//!  else the curve is non uniform. <br>
//!  The tolerance criterion is Epsilon from class Real. <br>
  Standard_EXPORT     GeomAbs_BSplKnotDistribution KnotDistribution() const;
  
//!  For a BSpline curve the last parameter (which gives the <br>
//!  end point of the curve) is a knot value but if the <br>
//!  multiplicity of the last knot index is lower than <br>
//!  Degree + 1 it is not the last knot of the curve. This <br>
//!  method computes the index of the knot corresponding to <br>
//!  the last parameter. <br>
  Standard_EXPORT     Standard_Integer LastUKnotIndex() const;
  
//!  Computes the parametric value of the end point of the curve. <br>
//!  It is a knot value. <br>
  Standard_EXPORT     Standard_Real LastParameter() const;
  
//!  Locates the parametric value U in the sequence of knots. <br>
//!  If "WithKnotRepetition" is True we consider the knot's <br>
//!  representation with repetition of multiple knot value, <br>
//!  otherwise  we consider the knot's representation with <br>
//!  no repetition of multiple knot values. <br>
//!  Knots (I1) <= U <= Knots (I2) <br>
//!  . if I1 = I2  U is a knot value (the tolerance criterion <br>
//!    ParametricTolerance is used). <br>
//!  . if I1 < 1  => U < Knots (1) - Abs(ParametricTolerance) <br>
//!  . if I2 > NbKnots => U > Knots (NbKnots) + Abs(ParametricTolerance) <br>
  Standard_EXPORT     void LocateU(const Standard_Real U,const Standard_Real ParametricTolerance,Standard_Integer& I1,Standard_Integer& I2,const Standard_Boolean WithKnotRepetition = Standard_False) const;
  
//!  Returns the multiplicity of the knots of range Index. <br>//! Raised if Index < 1 or Index > NbKnots <br>
  Standard_EXPORT     Standard_Integer Multiplicity(const Standard_Integer Index) const;
  
//!  Returns the multiplicity of the knots of the curve. <br>
//!  Raised if the length of M is not equal to NbKnots. <br>
  Standard_EXPORT     void Multiplicities(TColStd_Array1OfInteger& M) const;
  
//!  Returns the number of knots. This method returns the number of <br>
//!  knot without repetition of multiple knots. <br>
  Standard_EXPORT     Standard_Integer NbKnots() const;
  //! Returns the number of poles <br>
  Standard_EXPORT     Standard_Integer NbPoles() const;
  //! Returns the pole of range Index. <br>//! Raised if Index < 1 or Index > NbPoles. <br>
  Standard_EXPORT     gp_Pnt Pole(const Standard_Integer Index) const;
  //! Returns the poles of the B-spline curve; <br>
//!  Raised if the length of P is not equal to the number of poles. <br>
  Standard_EXPORT     void Poles(TColgp_Array1OfPnt& P) const;
  
//!  Returns the start point of the curve. <br>
//! Warnings : <br>
//!  This point is different from the first pole of the curve if the <br>
//!  multiplicity of the first knot is lower than Degree. <br>
  Standard_EXPORT     gp_Pnt StartPoint() const;
  //! Returns the weight of the pole of range Index . <br>//! Raised if Index < 1 or Index > NbPoles. <br>
  Standard_EXPORT     Standard_Real Weight(const Standard_Integer Index) const;
  //! Returns the weights of the B-spline curve; <br>
//!  Raised if the length of W is not equal to NbPoles. <br>
  Standard_EXPORT     void Weights(TColStd_Array1OfReal& W) const;
  //! Applies the transformation T to this BSpline curve. <br>
  Standard_EXPORT     void Transform(const gp_Trsf& T) ;
  
//!  Returns the value of the maximum degree of the normalized <br>
//!  B-spline basis functions in this package. <br>
  Standard_EXPORT   static  Standard_Integer MaxDegree() ;
  //!  Computes for this BSpline curve the parametric <br>
//! tolerance UTolerance for a given 3D tolerance Tolerance3D. <br>
//! If f(t) is the equation of this BSpline curve, <br>
//! UTolerance ensures that: <br>
//!           | t1 - t0| < Utolerance ===> <br>
//!           |f(t1) - f(t0)| < Tolerance3D <br>
  Standard_EXPORT     void Resolution(const Standard_Real Tolerance3D,Standard_Real& UTolerance) ;
  //! Creates a new object which is a copy of this BSpline curve. <br>
  Standard_EXPORT     Handle_Geom_Geometry Copy() const;




  DEFINE_STANDARD_RTTI(Geom_BSplineCurve)

protected:




private: 

  
//!           Tells whether the Cache is valid for the <br>
//!           given parameter <br>
//! Warnings : the parameter must be normalized within <br>
//! the period if the curve is periodic. Otherwise <br>
//! the answer will be false <br>
//! <br>
  Standard_EXPORT     Standard_Boolean IsCacheValid(const Standard_Real Parameter) const;
  //! Invalidates the cache. This has to be private <br>
//! this has to be private <br>
  Standard_EXPORT     void InvalidateCache() ;
  //! Recompute  the  flatknots,  the knotsdistribution, the continuity. <br>
  Standard_EXPORT     void UpdateKnots() ;
  //! updates the cache and validates it <br>
  Standard_EXPORT     void ValidateCache(const Standard_Real Parameter) ;

Standard_Boolean rational;
Standard_Boolean periodic;
GeomAbs_BSplKnotDistribution knotSet;
GeomAbs_Shape smooth;
Standard_Integer deg;
Handle_TColgp_HArray1OfPnt poles;
Handle_TColStd_HArray1OfReal weights;
Handle_TColStd_HArray1OfReal flatknots;
Handle_TColStd_HArray1OfReal knots;
Handle_TColStd_HArray1OfInteger mults;
Handle_TColgp_HArray1OfPnt cachepoles;
Handle_TColStd_HArray1OfReal cacheweights;
Standard_Integer validcache;
Standard_Real parametercache;
Standard_Real spanlenghtcache;
Standard_Integer spanindexcache;
Standard_Real maxderivinv;
Standard_Boolean maxderivinvok;


};





// other Inline functions and methods (like "C++: function call" methods)


#endif