This tool provides a method for computing pcurve by projecting 3d curve onto a surface. Projection is done by 23 or more points (this number is changed for B-Splines according to the following rule: the total number of the points is not less than number of spans * (degree + 1); it is increased recursively starting with 23 and is added with 22 until the condition is fulfilled). Isoparametric cases (if curve corresponds to U=const or V=const on the surface) are recognized with the given precision. More...

#include <ShapeConstruct_ProjectCurveOnSurface.hxx>

Inheritance diagram for ShapeConstruct_ProjectCurveOnSurface:

[legend]

Public Types
using	ArrayOfPnt = NCollection_Array1<gp_Pnt>

using	ArrayOfPnt2d = NCollection_Array1<gp_Pnt2d>

using	ArrayOfReal = NCollection_Array1<double>

using	CachePoint = std::pair<gp_Pnt, gp_Pnt2d>

using	CacheArray = NCollection_Array1<CachePoint>

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

Public Member Functions
	ShapeConstruct_ProjectCurveOnSurface ()
	Empty constructor.

virtual void	Init (const occ::handle< Geom_Surface > &theSurf, const double thePreci)
	Initializes the object with all necessary parameters, i.e. surface and precision.

virtual void	Init (const occ::handle< ShapeAnalysis_Surface > &theSurf, const double thePreci)
	Initializes the object with all necessary parameters, i.e. surface and precision.

void	SetSurface (const occ::handle< Geom_Surface > &theSurf)
	Loads a surface (in the form of Geom_Surface) to project on.

void	SetSurface (const occ::handle< ShapeAnalysis_Surface > &theSurf)
	Loads a surface (in the form of ShapeAnalysis_Surface) to project on.

void	SetPrecision (const double thePreci)
	Sets value for current precision.

int &	AdjustOverDegenMode ()
	Returns (modifiable) the flag specifying to which side of parametrical space adjust part of pcurve which lies on seam. This is required in very rare case when 3d curve which is to be projected goes partly along the seam on the closed surface with singularity (e.g. sphere), goes through the degenerated point and partly lies on internal area of surface.

bool	Status (const ShapeExtend_Status theStatus) const
	Returns the status of last Perform.

virtual bool	Perform (const occ::handle< Geom_Curve > &theC3D, const double theFirst, const double theLast, occ::handle< Geom2d_Curve > &theC2D, const double theTolFirst=Precision::Confusion(), const double theTolLast=Precision::Confusion())
	Computes the projection of 3d curve onto a surface using the specialized algorithm. Returns False if projector fails, otherwise, if pcurve computed successfully, returns True. The output curve 2D is guaranteed to be same-parameter with input curve 3D on the interval [theFirst, theLast]. If the output curve lies on a direct line the infinite line is returned, in the case same-parameter condition is satisfied.

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.

Protected Member Functions
occ::handle< Geom2d_Curve >	getLine (const ArrayOfPnt &thePoints, const ArrayOfReal &theParams, ArrayOfPnt2d &thePoints2d, const double theTol, bool &theIsRecompute, bool &theIsFromCache) const
	Try to approximate 3D curve by Geom2d_Line or Geom2d_BSplineCurve with degree 1 with specified tolerance.

bool	PerformByProjLib (const occ::handle< Geom_Curve > &theC3D, const double theFirst, const double theLast, occ::handle< Geom2d_Curve > &theC2D)
	Computes the projection of 3d curve onto a surface using the standard algorithm from ProjLib. Returns False if standard projector fails or raises an exception or cuts the curve by parametrical bounds of the surface. Else, if pcurve computed successfully, returns True.

occ::handle< Geom2d_Curve >	projectAnalytic (const occ::handle< Geom_Curve > &theC3D) const
	Performs analytical projection for special cases (plane surfaces)

bool	approxPCurve (const int theNbPnt, const occ::handle< Geom_Curve > &theC3D, const double theTolFirst, const double theTolLast, ArrayOfPnt &thePoints, ArrayOfReal &theParams, ArrayOfPnt2d &thePoints2d, occ::handle< Geom2d_Curve > &theC2D)
	Main approximation routine for pcurve computation.

void	correctExtremity (const occ::handle< Geom_Curve > &theC3D, const ArrayOfReal &theParams, ArrayOfPnt2d &thePoints2d, const bool theIsFirstPoint, const gp_Pnt2d &thePointOnIsoLine, const bool theIsUIso)
	Corrects extremity point near singularity.

void	insertAdditionalPointOrAdjust (bool &theToAdjust, const int theIndCoord, const double thePeriod, const double theTolOnPeriod, double &theCurCoord, const double thePrevCoord, const occ::handle< Geom_Curve > &theC3D, int &theIndex, ArrayOfPnt &thePoints, ArrayOfReal &theParams, ArrayOfPnt2d &thePoints2d)
	Inserts additional point or adjusts coordinate to handle period jumps.

occ::handle< Geom2d_Curve >	interpolatePCurve (const int theNbPnt, const ArrayOfPnt2d &thePoints2d, const ArrayOfReal &theParams) const
	Interpolates 2D curve from points.

occ::handle< Geom2d_Curve >	approximatePCurve (const ArrayOfPnt2d &thePoints2d, const ArrayOfReal &theParams) const
	Approximates 2D curve from points.

void	checkPoints (ArrayOfPnt &thePoints, ArrayOfReal &theParams, double &thePreci) const
	Checks and removes coincident 3D points.

void	checkPoints2d (ArrayOfPnt2d &thePoints2d, ArrayOfReal &theParams, double &thePreci) const
	Checks and removes coincident 2D points.

bool	isAnIsoparametric (const int theNbPnt, const ArrayOfPnt &thePoints, const ArrayOfReal &theParams, bool &theIsTypeU, bool &theP1OnIso, gp_Pnt2d &theValueP1, bool &theP2OnIso, gp_Pnt2d &theValueP2, bool &theIsoPar2d3d, occ::handle< Geom_Curve > &theCIso, double &theT1, double &theT2, ArrayOfReal &theParamsOut) const
	Detects if curve is isoparametric (U=const or V=const)

Additional Inherited Members
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

This tool provides a method for computing pcurve by projecting 3d curve onto a surface. Projection is done by 23 or more points (this number is changed for B-Splines according to the following rule: the total number of the points is not less than number of spans * (degree + 1); it is increased recursively starting with 23 and is added with 22 until the condition is fulfilled). Isoparametric cases (if curve corresponds to U=const or V=const on the surface) are recognized with the given precision.

Member Typedef Documentation

◆ ArrayOfPnt

using ShapeConstruct_ProjectCurveOnSurface::ArrayOfPnt = NCollection_Array1<gp_Pnt>

◆ ArrayOfPnt2d

using ShapeConstruct_ProjectCurveOnSurface::ArrayOfPnt2d = NCollection_Array1<gp_Pnt2d>

◆ ArrayOfReal

using ShapeConstruct_ProjectCurveOnSurface::ArrayOfReal = NCollection_Array1<double>

◆ CacheArray

using ShapeConstruct_ProjectCurveOnSurface::CacheArray = NCollection_Array1<CachePoint>

◆ CachePoint

using ShapeConstruct_ProjectCurveOnSurface::CachePoint = std::pair<gp_Pnt, gp_Pnt2d>

Constructor & Destructor Documentation

◆ ShapeConstruct_ProjectCurveOnSurface()

ShapeConstruct_ProjectCurveOnSurface::ShapeConstruct_ProjectCurveOnSurface ( )

Empty constructor.

Member Function Documentation

◆ AdjustOverDegenMode()

int & ShapeConstruct_ProjectCurveOnSurface::AdjustOverDegenMode ( )

Returns (modifiable) the flag specifying to which side of parametrical space adjust part of pcurve which lies on seam. This is required in very rare case when 3d curve which is to be projected goes partly along the seam on the closed surface with singularity (e.g. sphere), goes through the degenerated point and partly lies on internal area of surface.

If this flag is True, the seam part of such curve will be adjusted to the left side of parametric space (on sphere U=0), else to the right side (on sphere U=2*PI) Default value is True

Returns: modifiable reference to the adjustment flag

◆ approximatePCurve()

occ::handle< Geom2d_Curve > ShapeConstruct_ProjectCurveOnSurface::approximatePCurve	(	const ArrayOfPnt2d &	thePoints2d,
		const ArrayOfReal &	theParams ) const

protected

Approximates 2D curve from points.

Parameters

[in]	thePoints2d	array of 2D points
[in]	theParams	array of parameters

Returns: the approximated 2D curve or null on failure

◆ approxPCurve()

bool ShapeConstruct_ProjectCurveOnSurface::approxPCurve	(	const int	theNbPnt,
		const occ::handle< Geom_Curve > &	theC3D,
		const double	theTolFirst,
		const double	theTolLast,
		ArrayOfPnt &	thePoints,
		ArrayOfReal &	theParams,
		ArrayOfPnt2d &	thePoints2d,
		occ::handle< Geom2d_Curve > &	theC2D )

protected

Main approximation routine for pcurve computation.

Parameters

[in]	theNbPnt	number of points
[in]	theC3D	the 3D curve
[in]	theTolFirst	tolerance at first point
[in]	theTolLast	tolerance at last point
[in,out]	thePoints	array of 3D points
[in,out]	theParams	array of parameters
[out]	thePoints2d	array of 2D points
[out]	theC2D	resulting 2D curve

Returns: true if approximation succeeded

◆ checkPoints()

void ShapeConstruct_ProjectCurveOnSurface::checkPoints	(	ArrayOfPnt &	thePoints,
		ArrayOfReal &	theParams,
		double &	thePreci ) const

protected

Checks and removes coincident 3D points.

Parameters

[in,out]	thePoints	array of 3D points
[in,out]	theParams	array of parameters
[in,out]	thePreci	precision (may be adjusted)

◆ checkPoints2d()

void ShapeConstruct_ProjectCurveOnSurface::checkPoints2d	(	ArrayOfPnt2d &	thePoints2d,
		ArrayOfReal &	theParams,
		double &	thePreci ) const

protected

Checks and removes coincident 2D points.

Parameters

[in,out]	thePoints2d	array of 2D points
[in,out]	theParams	array of parameters
[in,out]	thePreci	precision (may be adjusted)

◆ correctExtremity()

void ShapeConstruct_ProjectCurveOnSurface::correctExtremity	(	const occ::handle< Geom_Curve > &	theC3D,
		const ArrayOfReal &	theParams,
		ArrayOfPnt2d &	thePoints2d,
		const bool	theIsFirstPoint,
		const gp_Pnt2d &	thePointOnIsoLine,
		const bool	theIsUIso )

protected

Corrects extremity point near singularity.

Parameters

[in]	theC3D	the 3D curve
[in]	theParams	array of parameters
[in,out]	thePoints2d	array of 2D points
[in]	theIsFirstPoint	true if correcting first point, false for last
[in]	thePointOnIsoLine	point on isoline
[in]	theIsUIso	true if U-isoline, false if V-isoline

◆ getLine()

occ::handle< Geom2d_Curve > ShapeConstruct_ProjectCurveOnSurface::getLine	(	const ArrayOfPnt &	thePoints,
		const ArrayOfReal &	theParams,
		ArrayOfPnt2d &	thePoints2d,
		const double	theTol,
		bool &	theIsRecompute,
		bool &	theIsFromCache ) const

protected

Try to approximate 3D curve by Geom2d_Line or Geom2d_BSplineCurve with degree 1 with specified tolerance.

Parameters

[in]	thePoints	points obtained from 3d curve
[in]	theParams	parameters corresponding points on 3d curve
[out]	thePoints2d	2d points lies on line in parametric space
[in]	theTol	tolerance used for compare initial points 3d and 3d points obtained from line lying in parametric space of surface
[out]	theIsRecompute	flag indicating if recomputation is needed
[out]	theIsFromCache	flag indicating if result is from cache

Returns: the resulting 2D curve or null if line fitting failed

◆ Init() [1/2]

virtual void ShapeConstruct_ProjectCurveOnSurface::Init	(	const occ::handle< Geom_Surface > &	theSurf,
		const double	thePreci )

virtual

Initializes the object with all necessary parameters, i.e. surface and precision.

Parameters

[in]	theSurf	the surface to project on
[in]	thePreci	the precision for projection

◆ Init() [2/2]

virtual void ShapeConstruct_ProjectCurveOnSurface::Init	(	const occ::handle< ShapeAnalysis_Surface > &	theSurf,
		const double	thePreci )

virtual

Initializes the object with all necessary parameters, i.e. surface and precision.

Parameters

[in]	theSurf	the surface to project on (ShapeAnalysis_Surface)
[in]	thePreci	the precision for projection

◆ insertAdditionalPointOrAdjust()

void ShapeConstruct_ProjectCurveOnSurface::insertAdditionalPointOrAdjust	(	bool &	theToAdjust,
		const int	theIndCoord,
		const double	thePeriod,
		const double	theTolOnPeriod,
		double &	theCurCoord,
		const double	thePrevCoord,
		const occ::handle< Geom_Curve > &	theC3D,
		int &	theIndex,
		ArrayOfPnt &	thePoints,
		ArrayOfReal &	theParams,
		ArrayOfPnt2d &	thePoints2d )

protected

Inserts additional point or adjusts coordinate to handle period jumps.

Parameters

[in,out]	theToAdjust	flag indicating if adjustment should be done
[in]	theIndCoord	coordinate index (1=U, 2=V)
[in]	thePeriod	the period value
[in]	theTolOnPeriod	tolerance on period
[in,out]	theCurCoord	current coordinate value
[in]	thePrevCoord	previous coordinate value
[in]	theC3D	the 3D curve
[in,out]	theIndex	current point index
[in,out]	thePoints	array of 3D points
[in,out]	theParams	array of parameters
[in,out]	thePoints2d	array of 2D points

◆ interpolatePCurve()

occ::handle< Geom2d_Curve > ShapeConstruct_ProjectCurveOnSurface::interpolatePCurve	(	const int	theNbPnt,
		const ArrayOfPnt2d &	thePoints2d,
		const ArrayOfReal &	theParams ) const

protected

Interpolates 2D curve from points.

Parameters

[in]	theNbPnt	number of points
[in]	thePoints2d	array of 2D points
[in]	theParams	array of parameters

Returns: the interpolated 2D curve or null on failure

◆ isAnIsoparametric()

bool ShapeConstruct_ProjectCurveOnSurface::isAnIsoparametric	(	const int	theNbPnt,
		const ArrayOfPnt &	thePoints,
		const ArrayOfReal &	theParams,
		bool &	theIsTypeU,
		bool &	theP1OnIso,
		gp_Pnt2d &	theValueP1,
		bool &	theP2OnIso,
		gp_Pnt2d &	theValueP2,
		bool &	theIsoPar2d3d,
		occ::handle< Geom_Curve > &	theCIso,
		double &	theT1,
		double &	theT2,
		ArrayOfReal &	theParamsOut ) const

protected

Detects if curve is isoparametric (U=const or V=const)

Parameters

[in]	theNbPnt	number of points
[in]	thePoints	array of 3D points
[in]	theParams	array of parameters
[out]	theIsTypeU	true if U-iso, false if V-iso
[out]	theP1OnIso	true if first point is on iso
[out]	theValueP1	2D value of first point on iso
[out]	theP2OnIso	true if last point is on iso
[out]	theValueP2	2D value of last point on iso
[out]	theIsoPar2d3d	true if parametrization matches
[out]	theCIso	the isoline curve
[out]	theT1	first iso parameter
[out]	theT2	last iso parameter
[out]	theParamsOut	output parameters on isoline

Returns: true if curve is isoparametric

◆ Perform()

virtual bool ShapeConstruct_ProjectCurveOnSurface::Perform	(	const occ::handle< Geom_Curve > &	theC3D,
		const double	theFirst,
		const double	theLast,
		occ::handle< Geom2d_Curve > &	theC2D,
		const double	theTolFirst = Precision::Confusion(),
		const double	theTolLast = Precision::Confusion() )

virtual

Computes the projection of 3d curve onto a surface using the specialized algorithm. Returns False if projector fails, otherwise, if pcurve computed successfully, returns True. The output curve 2D is guaranteed to be same-parameter with input curve 3D on the interval [theFirst, theLast]. If the output curve lies on a direct line the infinite line is returned, in the case same-parameter condition is satisfied.

Parameters

[in]	theC3D	the 3D curve to project
[in]	theFirst	the first parameter of the curve
[in]	theLast	the last parameter of the curve
[out]	theC2D	the resulting 2D curve
[in]	theTolFirst	the tolerance at the first point (default: Precision::Confusion())
[in]	theTolLast	the tolerance at the last point (default: Precision::Confusion())

Returns: true if projection succeeded

◆ PerformByProjLib()

bool ShapeConstruct_ProjectCurveOnSurface::PerformByProjLib	(	const occ::handle< Geom_Curve > &	theC3D,
		const double	theFirst,
		const double	theLast,
		occ::handle< Geom2d_Curve > &	theC2D )

protected

Computes the projection of 3d curve onto a surface using the standard algorithm from ProjLib. Returns False if standard projector fails or raises an exception or cuts the curve by parametrical bounds of the surface. Else, if pcurve computed successfully, returns True.

Parameters

[in]	theC3D	the 3D curve to project
[in]	theFirst	the first parameter of the curve
[in]	theLast	the last parameter of the curve
[out]	theC2D	the resulting 2D curve

Returns: true if projection succeeded

◆ projectAnalytic()

occ::handle< Geom2d_Curve > ShapeConstruct_ProjectCurveOnSurface::projectAnalytic ( const occ::handle< Geom_Curve > & theC3D ) const

protected

Performs analytical projection for special cases (plane surfaces)

Parameters

[in] theC3D the 3D curve to project

Returns: the resulting 2D curve or null if analytical projection not applicable

◆ SetPrecision()

void ShapeConstruct_ProjectCurveOnSurface::SetPrecision ( const double thePreci )

Sets value for current precision.

Parameters

[in] thePreci the precision value

◆ SetSurface() [1/2]

void ShapeConstruct_ProjectCurveOnSurface::SetSurface ( const occ::handle< Geom_Surface > & theSurf )

Loads a surface (in the form of Geom_Surface) to project on.

Parameters

[in] theSurf the surface to project on

◆ SetSurface() [2/2]

void ShapeConstruct_ProjectCurveOnSurface::SetSurface ( const occ::handle< ShapeAnalysis_Surface > & theSurf )

Loads a surface (in the form of ShapeAnalysis_Surface) to project on.

Parameters

[in] theSurf the surface to project on

◆ Status()

bool ShapeConstruct_ProjectCurveOnSurface::Status ( const ShapeExtend_Status theStatus ) const

Returns the status of last Perform.

Parameters

[in] theStatus the status to query

Returns: true if the specified status is set

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

ShapeConstruct_ProjectCurveOnSurface.hxx

Public Types

Public Member Functions

Protected Member Functions

Additional Inherited Members

Detailed Description

Member Typedef Documentation

◆ ArrayOfPnt

◆ ArrayOfPnt2d

◆ ArrayOfReal

◆ CacheArray

◆ CachePoint

Constructor & Destructor Documentation

◆ ShapeConstruct_ProjectCurveOnSurface()

Member Function Documentation

◆ AdjustOverDegenMode()

◆ approximatePCurve()

◆ approxPCurve()

◆ checkPoints()

◆ checkPoints2d()

◆ correctExtremity()

◆ getLine()

◆ Init() [1/2]

◆ Init() [2/2]

◆ insertAdditionalPointOrAdjust()

◆ interpolatePCurve()

◆ isAnIsoparametric()

◆ Perform()

◆ PerformByProjLib()

◆ projectAnalytic()

◆ SetPrecision()

◆ SetSurface() [1/2]

◆ SetSurface() [2/2]

◆ Status()