[occt.git] / src / GeomLib / GeomLib.cdl

-- Created on: 1993-07-07
-- Created by: Jean Claude VAUTHIER
-- Copyright (c) 1993-1999 Matra Datavision
-- Copyright (c) 1999-2012 OPEN CASCADE SAS
--
-- The content of this file is subject to the Open CASCADE Technology Public
-- License Version 6.5 (the "License"). You may not use the content of this file
-- except in compliance with the License. Please obtain a copy of the License
-- at http://www.opencascade.org and read it completely before using this file.
--
-- The Initial Developer of the Original Code is Open CASCADE S.A.S., having its
-- main offices at: 1, place des Freres Montgolfier, 78280 Guyancourt, France.
--
-- The Original Code and all software distributed under the License is
-- distributed on an "AS IS" basis, without warranty of any kind, and the
-- Initial Developer hereby disclaims all such warranties, including without
-- limitation, any warranties of merchantability, fitness for a particular
-- purpose or non-infringement. Please see the License for the specific terms
-- and conditions governing the rights and limitations under the License.

-- jct : modified 15-Apr-97 : added method ExtendSurfByLength


package GeomLib 

	---Purpose: Geom    Library.    This   package   provides   an
	--          implementation of  functions for basic computation
	--          on geometric entity from packages Geom and Geom2d.


uses 
    TCollection,
    TColStd,
    TColgp, 
    TColGeom, 
    TColGeom2d,
    Adaptor3d,
    AdvApprox,
    Geom, 
    Geom2d, 
    GeomAbs, 
    math,     
    gp,
    StdFail

is

    enumeration InterpolationErrors is 
	---Purpose: in case the interpolation errors out, this
	--          tells what happened
        NoError,
        NotEnoughtPoints,
	DegreeSmallerThan3,
	InversionProblem
	
    end InterpolationErrors;

    --    -- --------------- --
    --  C L A S S E S  --
    -- --------------- --
     
    class  Array1OfMat  instantiates   
    Array1 from TCollection  (Mat from gp);

    class MakeCurvefromApprox;
	---Purpose: This class is used to   create the curves ( 2d  or
	--          3d)  rational   or  not  created   by the    class
	--          ApproxAFunction from AdvApprox.


    class Interpolate ;
       ---Purpose: this class compute the poles of a curve given some
       --          parameters, points to interpolate and boundary conditions
       --          in 3d 
    class DenominatorMultiplier ;
       ---Purpose: this defines an evaluator for a function of 2 variables
       --          that will be used by CancelDenominatorDerivative in one
       --          direction.


    class CheckBSplineCurve ;
       ---Purpose:  Checks for the end  tangents : wether or not those
       --           are reversed regarding the third or n-3rd control
       --           
       --           
    class Check2dBSplineCurve ;     
            
       ---Purpose:  Checks for the end  tangents : wether or not those
       --           are reversed 

    class  IsPlanarSurface;
    
    class Tool;
    	---Purpose: provides various methods with Geom2d and Geom curves
	---         and surfaces.

    private  class  PolyFunc;  
     
    private  class  LogSample;

    pointer DenominatorMultiplierPtr to DenominatorMultiplier from GeomLib ;
    -------------------------
    --  M E T H O D E S  --
    -- ----------------- --

    To3d (Position : in     Ax2    from gp;
          Curve2d  : in     Curve  from Geom2d)
    returns Curve  from Geom;
    	---Purpose: Computes     the  curve  3d    from  package  Geom
    	--          corresponding to curve 2d  from package Geom2d, on
    	--          the plan defined with the local coordinate system
    	--          Position.
	      

    GTransform( Curve : in Curve    from Geom2d;
    	    	GTrsf : in GTrsf2d  from gp)
    returns Curve from Geom2d;
	---Purpose: Computes the    curve    3d  from   package   Geom
	--          corresponding  to the curve  3d from package Geom,
	--          transformed with the transformation <GTrsf>
	--          WARNING : this method may return a null Handle if
	--          it's impossible to compute the transformation of
	--          a curve. It's not implemented when :
	--          1) the curve is an infinite parabola or hyperbola
	--          2) the curve is an offsetcurve

    SameRange(Tolerance      : in  Real  from Standard ;
    	      Curve2dPtr     : in  Curve from Geom2d ;
    	      First          : in  Real  from Standard ;
	      Last           : in  Real  from Standard ;
	      RequestedFirst : in  Real  from Standard ;
	      RequestedLast  : in  Real  from Standard ;
	      NewCurve2dPtr  : out Curve from Geom2d) ;
    
     ---Purpose: Make the curve Curve2dPtr have the imposed
     --          range First to List the most economic way,
     --          that is if it can change the range without
     --          changing the nature of the curve it will try
     --          to do that. Otherwise it will produce a Bspline
     --          curve that has the required range 
     BuildCurve3d(Tolerance        : in  Real  from Standard ;
    	    	  CurvePtr         : in out  CurveOnSurface from Adaptor3d ; 
		  FirstParameter   : in  Real from Standard ;
		  LastParameter    : in  Real from Standard ;
		  NewCurvePtr      : out Curve from Geom ;
		  MaxDeviation     : out Real from Standard ;
		  AverageDeviation : out Real from Standard ;
		  Continuity       : Shape  from  GeomAbs  =  GeomAbs_C1;
    	          MaxDegree        : Integer  =  14; 
                  MaxSegment       : Integer  =  30); 
		   
     AdjustExtremity(Curve : in out BoundedCurve from Geom; 
     	             P1,  P2  :  Pnt  from  gp; 
		     T1,  T2  :  Vec  from  gp);
		  
     ExtendCurveToPoint(Curve : in out BoundedCurve from Geom;
     		        Point : Pnt from gp;
			Cont  : Integer from Standard;
			After : Boolean from Standard);
     ---Purpose: Extends the bounded curve Curve to the point Point.
-- The extension is built:
-- -      at the end of the curve if After equals true, or
-- -      at the beginning of the curve if After equals false.
--   The extension is performed according to a degree of
-- continuity equal to Cont, which in its turn must be equal to 1, 2 or 3.
-- This function converts the bounded curve Curve into a BSpline curve.
-- Warning
-- -   Nothing is done, and Curve is not modified if Cont is
--   not equal to 1, 2 or 3.
-- -   It is recommended that the extension should not be
--   too large with respect to the size of the bounded
--   curve Curve: Point must not be located too far from
--   one of the extremities of Curve.
	 
		  
     ExtendSurfByLength(Surf   : in out BoundedSurface from Geom;
     		        Length : Real from Standard;
			Cont   : Integer from Standard;
			InU    : Boolean from Standard;
			After  : Boolean from Standard);
     ---Purpose: 
-- Extends the bounded surface Surf along one of its
-- boundaries. The chord length of the extension is equal to Length.
-- The direction of the extension is given as:
-- -   the u parametric direction of Surf, if InU equals true,   or
-- -   the v parametric direction of Surf, if InU equals false.
-- In this parametric direction, the extension is built on the side of:
-- -   the last parameter of Surf, if After equals true, or
-- -   the first parameter of Surf, if After equals false.
-- The extension is performed according to a degree of
-- continuity equal to Cont, which in its turn must be equal to 1, 2 or 3.
-- This function converts the bounded surface Surf into a BSpline surface.
-- Warning
-- -   Nothing is done, and Surf is not modified if Cont is
--   not equal to 1, 2 or 3.
-- -   It is recommended that Length, the size of the
--   extension should not be too large with respect to the
 --  size of the bounded surface Surf.
-- -   Surf must not be a periodic BSpline surface in the
--   parametric direction corresponding to the direction of extension.
 
			   
     AxeOfInertia(Points      :  Array1OfPnt  from  TColgp;  
     	          Axe         :  out  Ax2  from  gp; 
		  IsSingular  :  out  Boolean; 
                  Tol         :  Real  =  1.0e-7); 
     ---Purpose: Compute   axes of inertia,  of some  points --  -- --
     --          <Axe>.Location() is the   BaryCentre -- -- --   -- --
     --          <Axe>.XDirection is the axe of upper inertia -- -- --
     --          -- <Axe>.Direction is the Normal to the average plane
     --          -- -- -- IsSingular is True if  points are on line --
     --          Tol is used to determine singular cases.
  
      Inertia(Points      :  Array1OfPnt  from  TColgp;  
     	      Bary        :  out  Pnt  from  gp;  
	      XDir,YDir   :  out  Dir from  gp; 
	      Xgap,YGap,ZGap  :  out  Real); 
	  ---Level: Advanced 
          ---Purpose:  Compute principale axes  of  inertia, and dispertion
     --            value  of some  points.

	        
     RemovePointsFromArray(NumPoints : Integer from Standard ;
     	                   InParameters : Array1OfReal from TColStd ;
			   OutParameters : in out HArray1OfReal from TColStd) ;
     ---Purpose: Warning!  This assume that the InParameter is an increasing sequence
     --          of real number and it will not check for that : Unpredictable
     --          result can happen if this is not satisfied. It is the caller
     --          responsability to check for that property. 
     --
     --  This  method makes uniform NumPoints segments S1,...SNumPoints out
     --          of the segment defined by the first parameter and the
     --          last  parameter ofthe  InParameter ; keeps   only one
     --          point of the InParameters set of parameter in each of
     --          the uniform segments taking care of the first and the
     --          last   parameters. For the ith segment the element of
     --          the InParameter is the one that is the first to exceed
     --          the midpoint of the segment and to fall before the 
     --          midpoint of the next segment
     --            There  will be  at  the  end at   most NumPoints + 1  if
     --          NumPoints > 2 in the OutParameters Array 
    
  
     DensifyArray1OfReal(MinNumPoints  : Integer from Standard ;
     	                 InParameters  : Array1OfReal from TColStd ;
			 OutParameters : in out HArray1OfReal from TColStd) ;
     ---Purpose: this  makes sure that there  is at least MinNumPoints
     --          in OutParameters taking into account the parameters in
     --          the InParameters array provided those are in order,
     --          that is the sequence of real in the InParameter is strictly
     --          non decreasing
     --          

     FuseIntervals(Interval1, Interval2 :  Array1OfReal from TColStd; 
     	           Fusion               :  out  SequenceOfReal	from TColStd; 
		   Confusion            :  Real  =  1.0e-9);	     

     EvalMaxParametricDistance(Curve : Curve from Adaptor3d ;
     	                       AReferenceCurve : Curve from Adaptor3d ;
			       Tolerance       : Real from Standard ;
			       Parameters      : Array1OfReal from TColStd ;
			       MaxDistance     : out Real from Standard) ;
			       
     ---Purpose:  this  will compute   the   maximum distance  at  the
     --          parameters  given    in   the Parameters  array    by
     --          evaluating each parameter  the two curves  and taking
     --          the maximum of the evaluated distance
     
     EvalMaxDistanceAlongParameter(Curve       : Curve from Adaptor3d ;
     	                       AReferenceCurve : Curve from Adaptor3d ;
			       Tolerance       : Real from Standard ;
			       Parameters      : Array1OfReal from TColStd ;
			       MaxDistance     : out Real from Standard) ;
     ---Purpose: this will compute the maximum distancef at the parameters
     --          given in the Parameters array by projecting from the Curve
     --          to the reference curve and taking the minimum distance
     --          Than the maximum will be taken on those minimas. 	
              
     CancelDenominatorDerivative(BSurf      :  in out  BSplineSurface from Geom ;
    	    	    	    	 UDirection : in Boolean        from Standard ;
    	    	    	    	 VDirection : in Boolean        from Standard) ;
     ---Purpose: Cancel,on the boudaries,the denominator  first derivative
     --          in  the directions wished by the user and set its value to 1.

 
--     TensorialProduct(S      : in out BSplineSurface from Geom; 
--     	              Poles  :  Array1OfMat  from  GeomLib; 
--		      TPoles :  Array1OfPnt  from  TColgp;	       
--                      Knots  :  Array1OfReal  from  TColStd; 
--		      Mults  :  Array1OfInteger  from  TColStd);
     --  Purpose:      Compute  the   Tensorial    product  beetween an
     --          BSplineSurface <S>(U,V) and  an Transformation Law M(v)
     --          given by NUBS form (<Poles>, <Knots>, <Mults>).  The result
     --          Surface is  R(U,V) = M(V)*S(U,V)+T(V). 
      
     NormEstim(S   :  Surface  from  Geom; 
     	       UV  :  Pnt2d  from  gp; 
	       Tol :  Real  from  Standard; 
	       N   :  in  out  Dir  from  gp) 
	        
	       returns  Integer  from  Standard;
     --  Purpose:  Computes  normal  of  surface  S  in  UV  point  UV
     --          for  regular  point  N  = DU^DV
     --          if |DU|  <  Tol  or  |DV|  <  Tol  special  treatment  is  used:
     --          N  is  computed on  base of  normal  of  corresponding  isoline 
     --          of  S 
     --          returns 0 for  regular  point,   
     --                  1 for  quasysingular (ex.: sphere  pole) 
     --                  2 for conical singular  point      
     --                  3 if computation impossible  (for ex. DU||DV - tangent isolines)


end GeomLib;
Commit	Line	Data
b311480e	1	-- Created on: 1993-07-07
	2	-- Created by: Jean Claude VAUTHIER
	3	-- Copyright (c) 1993-1999 Matra Datavision
	4	-- Copyright (c) 1999-2012 OPEN CASCADE SAS
	5	--
	6	-- The content of this file is subject to the Open CASCADE Technology Public
	7	-- License Version 6.5 (the "License"). You may not use the content of this file
	8	-- except in compliance with the License. Please obtain a copy of the License
	9	-- at http://www.opencascade.org and read it completely before using this file.
	10	--
	11	-- The Initial Developer of the Original Code is Open CASCADE S.A.S., having its
	12	-- main offices at: 1, place des Freres Montgolfier, 78280 Guyancourt, France.
	13	--
	14	-- The Original Code and all software distributed under the License is
	15	-- distributed on an "AS IS" basis, without warranty of any kind, and the
	16	-- Initial Developer hereby disclaims all such warranties, including without
	17	-- limitation, any warranties of merchantability, fitness for a particular
	18	-- purpose or non-infringement. Please see the License for the specific terms
	19	-- and conditions governing the rights and limitations under the License.
	20
7fd59977	21	-- jct : modified 15-Apr-97 : added method ExtendSurfByLength
	22
	23
	24	package GeomLib
	25
	26	---Purpose: Geom Library. This package provides an
	27	-- implementation of functions for basic computation
	28	-- on geometric entity from packages Geom and Geom2d.
	29
	30
	31	uses
	32	TCollection,
	33	TColStd,
	34	TColgp,
	35	TColGeom,
	36	TColGeom2d,
	37	Adaptor3d,
	38	AdvApprox,
	39	Geom,
	40	Geom2d,
	41	GeomAbs,
	42	math,
	43	gp,
	44	StdFail
	45
	46	is
	47
	48	enumeration InterpolationErrors is
	49	---Purpose: in case the interpolation errors out, this
	50	-- tells what happened
	51	NoError,
	52	NotEnoughtPoints,
	53	DegreeSmallerThan3,
	54	InversionProblem
	55
	56	end InterpolationErrors;
	57
	58	-- -- --------------- --
	59	-- C L A S S E S --
	60	-- --------------- --
	61
	62	class Array1OfMat instantiates
	63	Array1 from TCollection (Mat from gp);
	64
	65	class MakeCurvefromApprox;
	66	---Purpose: This class is used to create the curves ( 2d or
	67	-- 3d) rational or not created by the class
	68	-- ApproxAFunction from AdvApprox.
	69
	70
	71
	72	class Interpolate ;
	73	---Purpose: this class compute the poles of a curve given some
	74	-- parameters, points to interpolate and boundary conditions
	75	-- in 3d
	76	class DenominatorMultiplier ;
	77	---Purpose: this defines an evaluator for a function of 2 variables
	78	-- that will be used by CancelDenominatorDerivative in one
	79	-- direction.
	80
	81
	82	class CheckBSplineCurve ;
	83	---Purpose: Checks for the end tangents : wether or not those
	84	-- are reversed regarding the third or n-3rd control
85	--
86	--
87	class Check2dBSplineCurve ;
88
89	---Purpose: Checks for the end tangents : wether or not those
90	-- are reversed
91
92	class IsPlanarSurface;
93
94	class Tool;
95	---Purpose: provides various methods with Geom2d and Geom curves
96	--- and surfaces.
97
98	private class PolyFunc;
99
100	private class LogSample;
101
102	pointer DenominatorMultiplierPtr to DenominatorMultiplier from GeomLib ;
103	-------------------------
104	-- M E T H O D E S --
105	-- ----------------- --
106
107	To3d (Position : in Ax2 from gp;
108	Curve2d : in Curve from Geom2d)
109	returns Curve from Geom;
110	---Purpose: Computes the curve 3d from package Geom
111	-- corresponding to curve 2d from package Geom2d, on
112	-- the plan defined with the local coordinate system
113	-- Position.
114
115
116	GTransform( Curve : in Curve from Geom2d;
117	GTrsf : in GTrsf2d from gp)
118	returns Curve from Geom2d;
119	---Purpose: Computes the curve 3d from package Geom
120	-- corresponding to the curve 3d from package Geom,
121	-- transformed with the transformation <GTrsf>
122	-- WARNING : this method may return a null Handle if
123	-- it's impossible to compute the transformation of
124	-- a curve. It's not implemented when :
125	-- 1) the curve is an infinite parabola or hyperbola
126	-- 2) the curve is an offsetcurve
127
128	SameRange(Tolerance : in Real from Standard ;
129	Curve2dPtr : in Curve from Geom2d ;
130	First : in Real from Standard ;
131	Last : in Real from Standard ;
132	RequestedFirst : in Real from Standard ;
133	RequestedLast : in Real from Standard ;
134	NewCurve2dPtr : out Curve from Geom2d) ;
135
136	---Purpose: Make the curve Curve2dPtr have the imposed
137	-- range First to List the most economic way,
138	-- that is if it can change the range without
139	-- changing the nature of the curve it will try
140	-- to do that. Otherwise it will produce a Bspline
141	-- curve that has the required range
142	BuildCurve3d(Tolerance : in Real from Standard ;
143	CurvePtr : in out CurveOnSurface from Adaptor3d ;
144	FirstParameter : in Real from Standard ;
145	LastParameter : in Real from Standard ;
146	NewCurvePtr : out Curve from Geom ;
147	MaxDeviation : out Real from Standard ;
148	AverageDeviation : out Real from Standard ;
149	Continuity : Shape from GeomAbs = GeomAbs_C1;
150	MaxDegree : Integer = 14;
151	MaxSegment : Integer = 30);
152
153	AdjustExtremity(Curve : in out BoundedCurve from Geom;
154	P1, P2 : Pnt from gp;
155	T1, T2 : Vec from gp);
156
157	ExtendCurveToPoint(Curve : in out BoundedCurve from Geom;
158	Point : Pnt from gp;
159	Cont : Integer from Standard;
160	After : Boolean from Standard);
161	---Purpose: Extends the bounded curve Curve to the point Point.
162	-- The extension is built:
163	-- - at the end of the curve if After equals true, or
164	-- - at the beginning of the curve if After equals false.
165	-- The extension is performed according to a degree of
166	-- continuity equal to Cont, which in its turn must be equal to 1, 2 or 3.
167	-- This function converts the bounded curve Curve into a BSpline curve.
168	-- Warning
169	-- - Nothing is done, and Curve is not modified if Cont is
170	-- not equal to 1, 2 or 3.
171	-- - It is recommended that the extension should not be
172	-- too large with respect to the size of the bounded
173	-- curve Curve: Point must not be located too far from
174	-- one of the extremities of Curve.
175
176
177	ExtendSurfByLength(Surf : in out BoundedSurface from Geom;
178	Length : Real from Standard;
179	Cont : Integer from Standard;
180	InU : Boolean from Standard;
181	After : Boolean from Standard);
182	---Purpose:
183	-- Extends the bounded surface Surf along one of its
184	-- boundaries. The chord length of the extension is equal to Length.
185	-- The direction of the extension is given as:
186	-- - the u parametric direction of Surf, if InU equals true, or
187	-- - the v parametric direction of Surf, if InU equals false.
188	-- In this parametric direction, the extension is built on the side of:
189	-- - the last parameter of Surf, if After equals true, or
190	-- - the first parameter of Surf, if After equals false.
191	-- The extension is performed according to a degree of
192	-- continuity equal to Cont, which in its turn must be equal to 1, 2 or 3.
193	-- This function converts the bounded surface Surf into a BSpline surface.
194	-- Warning
195	-- - Nothing is done, and Surf is not modified if Cont is
196	-- not equal to 1, 2 or 3.
197	-- - It is recommended that Length, the size of the
198	-- extension should not be too large with respect to the
199	-- size of the bounded surface Surf.
200	-- - Surf must not be a periodic BSpline surface in the
201	-- parametric direction corresponding to the direction of extension.
202
203
204
205	AxeOfInertia(Points : Array1OfPnt from TColgp;
206	Axe : out Ax2 from gp;
207	IsSingular : out Boolean;
208	Tol : Real = 1.0e-7);
209	---Purpose: Compute axes of inertia, of some points -- -- --
210	-- <Axe>.Location() is the BaryCentre -- -- -- -- --
211	-- <Axe>.XDirection is the axe of upper inertia -- -- --
212	-- -- <Axe>.Direction is the Normal to the average plane
213	-- -- -- -- IsSingular is True if points are on line --
214	-- Tol is used to determine singular cases.
215
216	Inertia(Points : Array1OfPnt from TColgp;
217	Bary : out Pnt from gp;
218	XDir,YDir : out Dir from gp;
219	Xgap,YGap,ZGap : out Real);
220	---Level: Advanced
221	---Purpose: Compute principale axes of inertia, and dispertion
222	-- value of some points.
223
224
225	RemovePointsFromArray(NumPoints : Integer from Standard ;
226	InParameters : Array1OfReal from TColStd ;
227	OutParameters : in out HArray1OfReal from TColStd) ;
228	---Purpose: Warning! This assume that the InParameter is an increasing sequence
229	-- of real number and it will not check for that : Unpredictable
230	-- result can happen if this is not satisfied. It is the caller
231	-- responsability to check for that property.
232	--
233	-- This method makes uniform NumPoints segments S1,...SNumPoints out
234	-- of the segment defined by the first parameter and the
235	-- last parameter ofthe InParameter ; keeps only one
236	-- point of the InParameters set of parameter in each of
237	-- the uniform segments taking care of the first and the
238	-- last parameters. For the ith segment the element of
239	-- the InParameter is the one that is the first to exceed
240	-- the midpoint of the segment and to fall before the
241	-- midpoint of the next segment
242	-- There will be at the end at most NumPoints + 1 if
243	-- NumPoints > 2 in the OutParameters Array
244
245
246	DensifyArray1OfReal(MinNumPoints : Integer from Standard ;
247	InParameters : Array1OfReal from TColStd ;
248	OutParameters : in out HArray1OfReal from TColStd) ;
249	---Purpose: this makes sure that there is at least MinNumPoints
250	-- in OutParameters taking into account the parameters in
251	-- the InParameters array provided those are in order,
252	-- that is the sequence of real in the InParameter is strictly
253	-- non decreasing
254	--
255
256	FuseIntervals(Interval1, Interval2 : Array1OfReal from TColStd;
257	Fusion : out SequenceOfReal from TColStd;
258	Confusion : Real = 1.0e-9);
259
260	EvalMaxParametricDistance(Curve : Curve from Adaptor3d ;
261	AReferenceCurve : Curve from Adaptor3d ;
262	Tolerance : Real from Standard ;
263	Parameters : Array1OfReal from TColStd ;
264	MaxDistance : out Real from Standard) ;
265
266	---Purpose: this will compute the maximum distance at the
267	-- parameters given in the Parameters array by
268	-- evaluating each parameter the two curves and taking
269	-- the maximum of the evaluated distance
270
271	EvalMaxDistanceAlongParameter(Curve : Curve from Adaptor3d ;
272	AReferenceCurve : Curve from Adaptor3d ;
273	Tolerance : Real from Standard ;
274	Parameters : Array1OfReal from TColStd ;
275	MaxDistance : out Real from Standard) ;
276	---Purpose: this will compute the maximum distancef at the parameters
277	-- given in the Parameters array by projecting from the Curve
278	-- to the reference curve and taking the minimum distance
279	-- Than the maximum will be taken on those minimas.
280
281	CancelDenominatorDerivative(BSurf : in out BSplineSurface from Geom ;
282	UDirection : in Boolean from Standard ;
283	VDirection : in Boolean from Standard) ;
284	---Purpose: Cancel,on the boudaries,the denominator first derivative
285	-- in the directions wished by the user and set its value to 1.
286
287
288	-- TensorialProduct(S : in out BSplineSurface from Geom;
289	-- Poles : Array1OfMat from GeomLib;
290	-- TPoles : Array1OfPnt from TColgp;
291	-- Knots : Array1OfReal from TColStd;
292	-- Mults : Array1OfInteger from TColStd);
293	-- Purpose: Compute the Tensorial product beetween an
294	-- BSplineSurface <S>(U,V) and an Transformation Law M(v)
295	-- given by NUBS form (<Poles>, <Knots>, <Mults>). The result
296	-- Surface is R(U,V) = M(V)*S(U,V)+T(V).
297
298	NormEstim(S : Surface from Geom;
299	UV : Pnt2d from gp;
300	Tol : Real from Standard;
301	N : in out Dir from gp)
302
303	returns Integer from Standard;
304	-- Purpose: Computes normal of surface S in UV point UV
305	-- for regular point N = DU^DV
306	-- if \|DU\| < Tol or \|DV\| < Tol special treatment is used:
307	-- N is computed on base of normal of corresponding isoline
308	-- of S
309	-- returns 0 for regular point,
310	-- 1 for quasysingular (ex.: sphere pole)
311	-- 2 for conical singular point
312	-- 3 if computation impossible (for ex. DU\|\|DV - tangent isolines)
313
314
315	end GeomLib;
316
317