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--
-- File : BSplineCurve.cdl
-- Created : Sat 9 Jan 1993
-- Author : Kiran
--
---Copyright : MATRA-DATAVISION 1993
--
class BSplineCurve from IGESGeom inherits IGESEntity
---Purpose : defines IGESBSplineCurve, Type <126> Form <0-5>
-- in package IGESGeom
-- A parametric equation obtained by dividing two summations
-- involving weights (which are real numbers), the control
-- points, and B-Spline basis functions
uses
Pnt from gp,
XYZ from gp,
HArray1OfReal from TColStd,
HArray1OfXYZ from TColgp
raises DimensionMismatch, OutOfRange
is
Create returns mutable BSplineCurve;
-- Specific Methods pertaining to the class
Init (me : mutable;
anIndex : Integer;
aDegree : Integer;
aPlanar : Boolean;
aClosed : Boolean;
aPolynom : Boolean;
aPeriodic : Boolean;
allKnots : HArray1OfReal;
allWeights : HArray1OfReal;
allPoles : HArray1OfXYZ;
aUmin, aUmax : Real;
aNorm : XYZ)
raises DimensionMismatch;
---Purpose : This method is used to set the fields of the class
-- BSplineCurve. Beware about indexation of arrays
-- - anIndex : Upper index of the sum
-- - aDegree : Degree of basis functions
-- - aPlanar : 0 = nonplanar curve, 1 = planar curve
-- - aClosed : 0 = open curve, 1 = closed curve
-- - aPolynom : 0 = rational, 1 = polynomial
-- - aPeriodic : 0 = nonperiodic, 1 = periodic
-- - allKnots : Knot sequence values [-Degree,Index+1]
-- - allWeights : Array of weights [0,Index]
-- - allPoles : X, Y, Z coordinates of all control points
-- [0,Index]
-- - aUmin, aUmax : Starting and ending parameter values
-- - aNorm : Unit normal (if the curve is planar)
-- raises exception if allWeights & allPoles are not of same size.
SetFormNumber (me : mutable; form : Integer) raises OutOfRange;
---Purpose : Changes FormNumber (indicates the Shape of the Curve)
-- Error if not in range [0-5]
UpperIndex(me) returns Integer;
---Purpose : returns the upper index of the sum (see Knots,Poles)
Degree(me) returns Integer;
---Purpose : returns the degree of basis functions
IsPlanar(me) returns Boolean;
---Purpose : returns True if the curve is Planar, False if non-planar
IsClosed(me) returns Boolean;
---Purpose : returns True if the curve is closed, False if open
IsPolynomial(me; flag : Boolean = Standard_False) returns Boolean;
---Purpose : returns True if the curve is polynomial, False if rational
-- <flag> False (D) : computed from the list of weights
-- (all must be equal)
-- <flag> True : as recorded
IsPeriodic(me) returns Boolean;
---Purpose : returns True if the curve is periodic, False otherwise
NbKnots(me) returns Integer;
---Purpose : returns the number of knots (i.e. Degree + UpperIndex + 2)
Knot(me; anIndex : Integer) returns Real
raises OutOfRange;
---Purpose : returns the knot referred to by anIndex,
-- inside the range [-Degree,UpperIndex+1]
-- raises exception if
-- anIndex < -Degree() or anIndex > (NbKnots() - Degree())
-- Note : Knots are numbered from -Degree (not from 1)
NbPoles(me) returns Integer;
---Purpose : returns number of poles (i.e. UpperIndex + 1)
Weight(me; anIndex : Integer) returns Real
raises OutOfRange;
---Purpose : returns the weight referred to by anIndex, in [0,UpperIndex]
-- raises exception if anIndex < 0 or anIndex > UpperIndex()
Pole(me; anIndex : Integer) returns Pnt
raises OutOfRange;
---Purpose : returns the pole referred to by anIndex, in [0,UpperIndex]
-- raises exception if anIndex < 0 or anIndex > UpperIndex()
TransformedPole(me; anIndex : Integer) returns Pnt
raises OutOfRange;
---Purpose : returns the anIndex'th pole after applying Transf. Matrix
-- raises exception if an Index < 0 or an Index > UpperIndex()
UMin(me) returns Real;
---Purpose : returns starting parameter value
UMax(me) returns Real;
---Purpose : returns ending parameter value
Normal(me) returns XYZ;
---Purpose : if the curve is nonplanar then (0, 0, 0) is returned
fields
--
-- Class : IGESGeom_BSplineCurve
--
-- Purpose : Declaration of variables specific to the definition
-- of the Class BSplineCurve.
--
-- Reminder : A BSplineCurve instance is defined by :
-- A parametric equation obtained by dividing two summations
-- involving weights (which are real numbers), the control
-- points, and B-Spline basis functions
theIndex : Integer; -- Upper index of the sum
theDegree : Integer;
isPlanar : Boolean;
isClosed : Boolean;
isPolynomial : Boolean;
isPeriodic : Boolean;
theKnots : HArray1OfReal;
theWeights : HArray1OfReal;
thePoles : HArray1OfXYZ;
theUmin : Real; -- Starting parameter value
theUmax : Real; -- Ending parameter value
theNorm : XYZ;
end BSplineCurve;
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