A cache class for Bezier and B-spline surfaces. More...

#include <BSplSLib_Cache.hxx>

Inheritance diagram for BSplSLib_Cache:

Public Member Functions
	BSplSLib_Cache (const int &theDegreeU, const bool &thePeriodicU, const NCollection_Array1< double > &theFlatKnotsU, const int &theDegreeV, const bool &thePeriodicV, const NCollection_Array1< double > &theFlatKnotsV, const NCollection_Array2< double > *theWeights=nullptr)
	Constructor for caching of the span for the surface.

bool	IsCacheValid (double theParameterU, double theParameterV) const
	Verifies validity of the cache using parameters of the point.

void	BuildCache (const double &theParameterU, const double &theParameterV, const NCollection_Array1< double > &theFlatKnotsU, const NCollection_Array1< double > &theFlatKnotsV, const NCollection_Array2< gp_Pnt > &thePoles, const NCollection_Array2< double > *theWeights=nullptr)
	Recomputes the cache data. Does not verify validity of the cache.

void	D0 (const double &theU, const double &theV, gp_Pnt &thePoint) const
	Calculates the point on the surface for specified parameters.

void	D1 (const double &theU, const double &theV, gp_Pnt &thePoint, gp_Vec &theTangentU, gp_Vec &theTangentV) const
	Calculates the point on the surface and its first derivative.

void	D2 (const double &theU, const double &theV, gp_Pnt &thePoint, gp_Vec &theTangentU, gp_Vec &theTangentV, gp_Vec &theCurvatureU, gp_Vec &theCurvatureV, gp_Vec &theCurvatureUV) const
	Calculates the point on the surface and derivatives till second order.

void	D0Local (double theLocalU, double theLocalV, gp_Pnt &thePoint) const
	Calculates the point using pre-computed local parameters in [-1, 1] range. This bypasses periodic normalization and local parameter calculation.

void	D1Local (double theLocalU, double theLocalV, gp_Pnt &thePoint, gp_Vec &theTangentU, gp_Vec &theTangentV) const
	Calculates the point and first derivatives using pre-computed local parameters in [-1, 1] range. This bypasses periodic normalization and local parameter calculation.

void	D2Local (double theLocalU, double theLocalV, gp_Pnt &thePoint, gp_Vec &theTangentU, gp_Vec &theTangentV, gp_Vec &theCurvatureU, gp_Vec &theCurvatureV, gp_Vec &theCurvatureUV) const
	Calculates the point and derivatives till second order using pre-computed local parameters. This bypasses periodic normalization and local parameter calculation.

Public Member Functions inherited from Standard_Transient
	Standard_Transient ()
	Empty constructor.

	Standard_Transient (const Standard_Transient &)
	Copy constructor – does nothing.

Standard_Transient &	operator= (const Standard_Transient &)
	Assignment operator, needed to avoid copying reference counter.

virtual	~Standard_Transient ()=default
	Destructor must be virtual.

virtual const opencascade::handle< Standard_Type > &	DynamicType () const
	Returns a type descriptor about this object.

bool	IsInstance (const opencascade::handle< Standard_Type > &theType) const
	Returns a true value if this is an instance of Type.

bool	IsInstance (const char *const theTypeName) const
	Returns a true value if this is an instance of TypeName.

bool	IsKind (const opencascade::handle< Standard_Type > &theType) const
	Returns true if this is an instance of Type or an instance of any class that inherits from Type. Note that multiple inheritance is not supported by OCCT RTTI mechanism.

bool	IsKind (const char *const theTypeName) const
	Returns true if this is an instance of TypeName or an instance of any class that inherits from TypeName. Note that multiple inheritance is not supported by OCCT RTTI mechanism.

Standard_Transient *	This () const
	Returns non-const pointer to this object (like const_cast). For protection against creating handle to objects allocated in stack or call from constructor, it will raise exception Standard_ProgramError if reference counter is zero.

int	GetRefCount () const noexcept
	Get the reference counter of this object.

void	IncrementRefCounter () noexcept
	Increments the reference counter of this object. Uses relaxed memory ordering since incrementing only requires atomicity, not synchronization with other memory operations.

int	DecrementRefCounter () noexcept
	Decrements the reference counter of this object; returns the decremented value. Uses release ordering for the decrement to ensure all writes to the object are visible before the count reaches zero. An acquire fence is added only when the count reaches zero, ensuring proper synchronization before deletion. This is more efficient than using acq_rel for every decrement.

virtual void	Delete () const
	Memory deallocator for transient classes.

Additional Inherited Members
Public Types inherited from Standard_Transient
typedef void	base_type
	Returns a type descriptor about this object.

Static Public Member Functions inherited from Standard_Transient
static constexpr const char *	get_type_name ()
	Returns a type descriptor about this object.

static const opencascade::handle< Standard_Type > &	get_type_descriptor ()
	Returns type descriptor of Standard_Transient class.

Detailed Description

A cache class for Bezier and B-spline surfaces.

Defines all data, that can be cached on a span of the surface. The data should be recalculated in going from span to span.

Constructor & Destructor Documentation

◆ BSplSLib_Cache()

BSplSLib_Cache::BSplSLib_Cache	(	const int &	theDegreeU,
		const bool &	thePeriodicU,
		const NCollection_Array1< double > &	theFlatKnotsU,
		const int &	theDegreeV,
		const bool &	thePeriodicV,
		const NCollection_Array1< double > &	theFlatKnotsV,
		const NCollection_Array2< double > *	theWeights = nullptr )

Constructor for caching of the span for the surface.

Parameters

theDegreeU	degree along the first parameter (U) of the surface
thePeriodicU	identify the surface is periodical along U axis
theFlatKnotsU	knots of the surface (with repetition) along U axis
theDegreeV	degree along the second parameter (V) of the surface
thePeriodicV	identify the surface is periodical along V axis
theFlatKnotsV	knots of the surface (with repetition) along V axis
theWeights	array of weights of corresponding poles

Member Function Documentation

◆ BuildCache()

void BSplSLib_Cache::BuildCache	(	const double &	theParameterU,
		const double &	theParameterV,
		const NCollection_Array1< double > &	theFlatKnotsU,
		const NCollection_Array1< double > &	theFlatKnotsV,
		const NCollection_Array2< gp_Pnt > &	thePoles,
		const NCollection_Array2< double > *	theWeights = nullptr )

Recomputes the cache data. Does not verify validity of the cache.

Parameters

theParameterU	the parametric value on the U axis to identify the span
theParameterV	the parametric value on the V axis to identify the span
theDegreeU	degree along U axis
thePeriodicU	identify whether the surface is periodic along U axis
theFlatKnotsU	flat knots of the surface along U axis
theDegreeV	degree along V axis
thePeriodicV	identify whether the surface is periodic along V axis
theFlatKnotsV	flat knots of the surface along V axis
thePoles	array of poles of the surface
theWeights	array of weights of corresponding poles

◆ D0()

void BSplSLib_Cache::D0	(	const double &	theU,
		const double &	theV,
		gp_Pnt &	thePoint ) const

Calculates the point on the surface for specified parameters.

Parameters

[in]	theU	first parameter for calculation of the value
[in]	theV	second parameter for calculation of the value
[out]	thePoint	the result of calculation (the point on the surface)

◆ D0Local()

void BSplSLib_Cache::D0Local	(	double	theLocalU,
		double	theLocalV,
		gp_Pnt &	thePoint ) const

Calculates the point using pre-computed local parameters in [-1, 1] range. This bypasses periodic normalization and local parameter calculation.

Parameters

[in]	theLocalU	pre-computed local U parameter: (U - SpanMid) / SpanHalfLen
[in]	theLocalV	pre-computed local V parameter: (V - SpanMid) / SpanHalfLen
[out]	thePoint	the result of calculation (the point on the surface)

◆ D1()

void BSplSLib_Cache::D1	(	const double &	theU,
		const double &	theV,
		gp_Pnt &	thePoint,
		gp_Vec &	theTangentU,
		gp_Vec &	theTangentV ) const

Calculates the point on the surface and its first derivative.

Parameters

[in]	theU	first parameter of calculation of the value
[in]	theV	second parameter of calculation of the value
[out]	thePoint	the result of calculation (the point on the surface)
[out]	theTangentU	tangent vector along U axis in the calculated point
[out]	theTangentV	tangent vector along V axis in the calculated point

◆ D1Local()

void BSplSLib_Cache::D1Local	(	double	theLocalU,
		double	theLocalV,
		gp_Pnt &	thePoint,
		gp_Vec &	theTangentU,
		gp_Vec &	theTangentV ) const

Calculates the point and first derivatives using pre-computed local parameters in [-1, 1] range. This bypasses periodic normalization and local parameter calculation.

Parameters

[in]	theLocalU	pre-computed local U parameter: (U - SpanMid) / SpanHalfLen
[in]	theLocalV	pre-computed local V parameter: (V - SpanMid) / SpanHalfLen
[out]	thePoint	the result of calculation (the point on the surface)
[out]	theTangentU	tangent vector along U axis in the calculated point
[out]	theTangentV	tangent vector along V axis in the calculated point

◆ D2()

void BSplSLib_Cache::D2	(	const double &	theU,
		const double &	theV,
		gp_Pnt &	thePoint,
		gp_Vec &	theTangentU,
		gp_Vec &	theTangentV,
		gp_Vec &	theCurvatureU,
		gp_Vec &	theCurvatureV,
		gp_Vec &	theCurvatureUV ) const

Calculates the point on the surface and derivatives till second order.

Parameters

[in]	theU	first parameter of calculation of the value
[in]	theV	second parameter of calculation of the value
[out]	thePoint	the result of calculation (the point on the surface)
[out]	theTangentU	tangent vector along U axis in the calculated point
[out]	theTangentV	tangent vector along V axis in the calculated point
[out]	theCurvatureU	curvature vector (2nd derivative on U) along U axis
[out]	theCurvatureV	curvature vector (2nd derivative on V) along V axis
[out]	theCurvatureUV	2nd mixed derivative on U anv V

◆ D2Local()

void BSplSLib_Cache::D2Local	(	double	theLocalU,
		double	theLocalV,
		gp_Pnt &	thePoint,
		gp_Vec &	theTangentU,
		gp_Vec &	theTangentV,
		gp_Vec &	theCurvatureU,
		gp_Vec &	theCurvatureV,
		gp_Vec &	theCurvatureUV ) const

Calculates the point and derivatives till second order using pre-computed local parameters. This bypasses periodic normalization and local parameter calculation.

Parameters

[in]	theLocalU	pre-computed local U parameter: (U - SpanMid) / SpanHalfLen
[in]	theLocalV	pre-computed local V parameter: (V - SpanMid) / SpanHalfLen
[out]	thePoint	the result of calculation (the point on the surface)
[out]	theTangentU	tangent vector along U axis in the calculated point
[out]	theTangentV	tangent vector along V axis in the calculated point
[out]	theCurvatureU	curvature vector (2nd derivative on U) along U axis
[out]	theCurvatureV	curvature vector (2nd derivative on V) along V axis
[out]	theCurvatureUV	2nd mixed derivative on U and V

◆ IsCacheValid()

bool BSplSLib_Cache::IsCacheValid	(	double	theParameterU,
		double	theParameterV ) const

Verifies validity of the cache using parameters of the point.

Parameters

theParameterU	first parameter of the point placed in the span
theParameterV	second parameter of the point placed in the span

The documentation for this class was generated from the following file:

BSplSLib_Cache.hxx

Public Member Functions

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ BSplSLib_Cache()

Member Function Documentation

◆ BuildCache()

◆ D0()

◆ D0Local()

◆ D1()

◆ D1Local()

◆ D2()

◆ D2Local()

◆ IsCacheValid()