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IKO_GeomAPI_Interpolate

# IKO_GeomAPI_Interpolate Interface

The interface is used to interpolate a BsplineCurve passing through an array of points, with a C2 Continuity if tangency is not requested at the point. If tangency is requested at the point the continuity will be C1. If Perodicity is requested the curve will be closed and the junction will be the first point given. The curve will than be only C1 Describes functions for building a constrained 3D BSpline curve. The curve is defined by a table of points through which it passes, and if required:
ï¿½ by a parallel table of reals which gives the value of the parameter of each point through which the resulting BSpline curve passes, and
ï¿½ by vectors tangential to these points. An Interpolate object provides a framework for:
ï¿½ defining the constraints of the BSpline curve,
ï¿½ implementing the interpolation algorithm, and
ï¿½ consulting the results.

Init
Init2
ClearTangents
Perform
Curve

HRESULT Init(IKO_TColgp_Array1OfPnt* Points, VARIANT_BOOL Periodic, double Tolerance)

Initializes an algorithm for constructing a constrained BSpline curve passing through the points of the table Points. Tangential vectors can then be assigned, using the function Load. If PeriodicFlag is true, the constrained BSpline curve will be periodic and closed. In this case, the junction point is the first point of the table Points. The tolerance value Tolerance is used to check that: ï¿½ points are not too close to each other, or tangential vectors (defined using the function Load) are not too small. The resulting BSpline curve will be "C2" continuous, except where a tangency constraint is defined on a point through which the curve passes (by using the Load function). In this case, it will be only "C1" continuous. Once all the constraints are defined, use the function Perform to compute the curve. Warning
ï¿½ There must be at least 2 points in the table Points.
ï¿½ If PeriodicFlag is false, there must be as
many parameters in the array Parameters as there are points in the array Points.
ï¿½ If PeriodicFlag is true, there must be one more parameter in the table Parameters: this is used to give the parameter on the resulting BSpline curve of the junction point of the curve (which is also the first point of the table Points). Exceptions
ï¿½ Standard_ConstructionError if the distance between two consecutive points in the table Points is less than or equal to Tolerance.
ï¿½ Standard_OutOfRange if:
o there are less than two points in the table Points, or
o conditions relating to the respective
number of elements in the parallel tables Points and Parameters are not respected.

HRESULT Init2(IKO_TColgp_Array1OfPnt* Points, IKO_TColStd_Array1OfReal* Parameters, VARIANT_BOOL Periodic, double Tolerance)

Initializes an algorithm for constructing a constrained BSpline curve passing through the points of the table Points, where the parameters of each of its points are given by the parallel table Parameters. Tangential vectors can then be assigned, using the function Load. If PeriodicFlag is true, the constrained BSpline curve will be periodic and closed. In this case, the junction point is the first point of the table Points.

The tolerance value Tolerance is used to check that: points are not too close to each other, or tangential vectors (defined using the function Load) are not too small. The resulting BSpline curve will be "C2" continuous, except where a tangency constraint is defined on a point through which the curve passes (by using the Load function). In this case, it will be only "C1" continuous. Once all the constraints are defined, use the function Perform to compute the curve.

Warning There must be at least 2 points in the table Points. If PeriodicFlag is false, there must be as many parameters in the array Parameters as there are points in the array Points. If PeriodicFlag is true, there must be one more parameter in the table Parameters: this is used to give the parameter on the resulting BSpline curve of the junction point of the curve (which is also the first point of the table Points).

Exceptions: Standard_ConstructionError if the distance between two consecutive points in the table Points is less than or equal to Tolerance. Standard_OutOfRange if: there are less than two points in the table Points, or conditions relating to the respective number of elements in the parallel tables Points and Parameters are not respected

HRESULT Load( DIVect* InitialTangent, DIVect* FinalTangent, VARIANT_BOOL Scale)

Assigns this constrained BSpline curve to be tangential to vectors InitialTangent and FinalTangent at its first and last points respectively (i.e. the first and last points of the table of points through which the curve passes, as defined at the time of initialization).

HRESULT Load2(IKO_TColgp_Array1OfVec* Tangents, IKO_TColStd_Array1OfBoolean* TangentFlags, VARIANT_BOOL Scale)

Assigns this constrained BSpline curve to be tangential to vectors defined in the table Tangents, which is parallel to the table of points through which the curve passes, as defined at the time of initialization. Vectors in the table Tangents are defined only if the flag given in the parallel table TangentFlags is true: only these vectors are set as tangency constraints.

HRESULT ClearTangents()

Clears all tangency constraints on this constrained BSpline curve (as initialized by the function Load).

HRESULT Perform()

Computes the constrained BSpline curve. Use the function IsDone to verify that the computation is successful, and then the function Curve to obtain the result.

HRESULT Curve(IKO_Geom_BSplineCurve** curve)

Returns the computed BSpline curve. Raises StdFail_NotDone if the interpolation fails.