#include <opennurbs_nurbscurve.h>

Inheritance diagram for ON_NurbsCurve:

Public Member Functions
	ON_NurbsCurve () ON_NOEXCEPT

	ON_NurbsCurve (const ON_NurbsCurve &)

	ON_NurbsCurve (const ON_BezierCurve &bezier_curve)
	Create a NURBS curve equal to bezier with domain [0,1]. More...

	ON_NurbsCurve (int dimension, bool bIsRational, int order, int cv_count)
	Create a NURBS curve with knot a cv memory allocated. More...

virtual	~ON_NurbsCurve ()

bool	Append (const ON_NurbsCurve &)

bool	ChangeClosedCurveSeam (double t) override
	If this curve is closed, then modify it so that the start/end point is at curve parameter t. More...

bool	ChangeDimension (int desired_dimension) override
	Change the dimension of a curve. More...

bool	ChangeEndWeights (double w0, double w1)
	Use a combination of scaling and reparameterization to change the end weights to the specified values. More...

bool	ClampEnd (int end)
	Clamp end knots. Does not modify control points. More...

const ON_4dPoint	ControlPoint (int cv_index) const

double	ControlPolygonLength () const
	returns the length of the control polygon More...

bool	ConvertSpanToBezier (int, ON_BezierCurve &) const

bool	Create (int dimension, bool bIsRational, int order, int cv_count)
	Create a NURBS curve with knot a cv memory allocated. More...

bool	CreateClampedUniformNurbs (int dimension, int order, int point_count, const ON_3dPoint *point, double knot_delta=1.0)
	Create a clamped uniform NURBS curve from a list of control points More...

bool	CreatePeriodicUniformNurbs (int dimension, int order, int point_count, const ON_3dPoint *point, double knot_delta=1.0)
	Create a periodic uniform NURBS curve from a list of control points More...

double *	CV (int cv_index) const
	Expert user function to get a pointer to control vertex memory. If you are not an expert user, please use ON_NurbsCurve::GetCV( ON_3dPoint& ) or ON_NurbsCurve::GetCV( ON_4dPoint& ). More...

int	CVCount (void) const

int	CVSize (void) const

ON::point_style	CVStyle () const
	Returns the style of control vertices in the m_cv array. More...

ON__UINT32	DataCRC (ON__UINT32 current_remainder) const override
	virtual ON_Object::DataCRC override More...

int	Degree () const override
	virtual ON_Curve::Degree override. More...

void	Destroy ()
	Deallocate knot and cv memory. Zeros all fields. More...

int	Dimension () const override
	ON_Geometry overrides. More...

ON_Interval	Domain () const override
	ON_Curve overrides. More...

void	Dump (ON_TextLog &dump) const override
	virtual ON_Object::Dump override More...

void	EmergencyDestroy ()
	Call if memory used by ON_NurbsCurve becomes invalid. More...

bool	Evaluate (double, int, int, double , int=0, int =0) const override
	virtual ON_Curve::Evaluate override. More...

bool	Extend (const ON_Interval &domain) override
	Where possible, analytically extends curve to include domain. More...

bool	GetBBox (double boxmin, double boxmax, bool bGrowBox=false) const override
	virtual ON_Geometry GetBBox override More...

bool	GetCurveParameterFromNurbFormParameter (double nurbs_t, double *curve_t) const override
	virtual ON_Curve::GetCurveParameterFromNurbFormParameter override More...

bool	GetCV (int, ON::point_style, double *) const

bool	GetCV (int, ON_3dPoint &) const

bool	GetCV (int, ON_4dPoint &) const

bool	GetGrevilleAbcissae (double *) const

bool	GetNextDiscontinuity (ON::continuity c, double t0, double t1, double t, int hint=nullptr, int *dtype=nullptr, double cos_angle_tolerance=ON_DEFAULT_ANGLE_TOLERANCE_COSINE, double curvature_tolerance=ON_SQRT_EPSILON) const override
	Search for a derivatitive, tangent, or curvature discontinuity. More...

int	GetNurbForm (ON_NurbsCurve &nurbsform, double tolerance=0.0, const ON_Interval *subdomain=nullptr) const override
	virtual ON_Curve::GetNurbForm override. More...

bool	GetNurbFormParameterFromCurveParameter (double curve_t, double *nurbs_t) const override
	virtual ON_Curve::GetNurbFormParameterFromCurveParameter override More...

bool	GetParameterTolerance (double t, double tminus, double tplus) const override
	virtual ON_Curve::GetParameterTolerance override. More...

bool	GetSpanVector (double *knot_values) const override
	virtual ON_Curve::GetSpanVector override. Get number of parameters of distinct knots in NURBS curve's domain. More...

double	GrevilleAbcissa (int) const

bool	HasBezierSpans () const

int	HasNurbForm () const override
	virtual ON_Curve::HasNurbForm override. More...

bool	IncreaseDegree (int desired_degree)

void	Initialize (void)
	Zeros all fields. More...

bool	InsertKnot (double knot_value, int knot_multiplicity)
	Insert a knot and update cv locations. More...

bool	IsArc (const ON_Plane plane=nullptr, ON_Arc arc=nullptr, double tolerance=ON_ZERO_TOLERANCE) const override
	virtual ON_Curve::IsArc override. More...

bool	IsClamped (int=2) const

bool	IsClosed () const override
	virtual ON_Curve::IsClosed override. More...

bool	IsContinuous (ON::continuity c, double t, int *hint=nullptr, double point_tolerance=ON_ZERO_TOLERANCE, double d1_tolerance=ON_ZERO_TOLERANCE, double d2_tolerance=ON_ZERO_TOLERANCE, double cos_angle_tolerance=ON_DEFAULT_ANGLE_TOLERANCE_COSINE, double curvature_tolerance=ON_SQRT_EPSILON) const override
	Test continuity at a curve parameter value. More...

bool	IsDeformable () const override
	virtual ON_Geometry::IsDeformable() override More...

bool	IsDuplicate (const ON_NurbsCurve &other, bool bIgnoreParameterization, double tolerance=ON_ZERO_TOLERANCE) const
	See if this and other are same NURBS geometry. More...

bool	IsInPlane (const ON_Plane &test_plane, double tolerance=ON_ZERO_TOLERANCE) const override
	virtual ON_Curve::IsInPlane override. More...

bool	IsLinear (double tolerance=ON_ZERO_TOLERANCE) const override
	virtual ON_Curve::IsLinear override. More...

bool	IsPeriodic () const override
	virtual ON_Curve::IsPeriodic override. More...

bool	IsPlanar (ON_Plane *plane=nullptr, double tolerance=ON_ZERO_TOLERANCE) const override
	virtual ON_Curve::IsPlanar override. More...

int	IsPolyline (ON_SimpleArray< ON_3dPoint > pline_points=nullptr, ON_SimpleArray< double > pline_t=nullptr) const override
	Several types of ON_Curve can have the form of a polyline including a degree 1 ON_NurbsCurve, an ON_PolylineCurve, and an ON_PolyCurve all of whose segments are some form of polyline. IsPolyline tests a curve to see if it can be represented as a polyline. More...

bool	IsRational (void) const
	Interface. More...

bool	IsSingular () const

bool	IsValid (class ON_TextLog *text_log=nullptr) const override
	ON_Object overrides. More...

double	Knot (int knot_index) const
	Get knot value. More...

const double *	Knot () const
	Get pointer to knot vector array. More...

int	KnotCount (void) const

int	KnotMultiplicity (int knot_index) const
	Get knot multiplicity. More...

bool	MakeClampedUniformKnotVector (double delta=1.0)
	Make knot vector a clamped uniform knot vector based on the current values of m_order and m_cv_count. Does not change values of control vertices. More...

bool	MakeDeformable () override
	virtual ON_Geometry::MakeDeformable() override More...

bool	MakeNonRational ()

bool	MakePeriodicUniformKnotVector (double delta=1.0)
	Make knot vector a periodic uniform knot vector based on the current values of m_order and m_cv_count. Does not change values of control vertices. More...

bool	MakePiecewiseBezier (bool bSetEndWeightsToOne=false)
	Clamps ends and adds knots so the NURBS curve has bezier spans (all distinct knots have multiplitity = degree). Paremeters: bSetEndWeightsToOne - [in] If true and the first or last weight is not one, then the first and last spans are reparameterized so that the end weights are one. More...

bool	MakeRational ()

ON_NurbsCurve &	operator= (const ON_NurbsCurve &src)

ON_NurbsCurve &	operator= (const ON_BezierCurve &bezier_curve)
	Set NURBS curve equal to bezier with domain [0,1]. More...

int	Order (void) const

bool	Read (ON_BinaryArchive &binary_archive) override
	virtual ON_Object::Read override More...

int	RemoveSingularSpans ()

bool	RemoveSpan (int span_index)

bool	RepairBadKnots (double knot_tolerance=0.0, bool bRepair=true)
	Looks for problems caused by knots that are close together or have mulitplicity >= order. If bRepair is true, the problems are fixed. Does not change the domain. More...

bool	Reparameterize (double c)
	Use a linear fractional transformation to reparameterize the NURBS curve. This does not change the curve's domain. More...

bool	ReserveCVCapacity (int)
	Tools for managing CV and knot memory. More...

bool	ReserveKnotCapacity (int)

bool	Reverse () override
	virtual ON_Curve::Reverse override. Reverse parameterizatrion by negating all knots and reversing the order of the control vertices. More...

bool	SetCV (int, ON::point_style, const double *)

bool	SetCV (int, const ON_3dPoint &)

bool	SetCV (int, const ON_4dPoint &)

bool	SetDomain (double t0, double t1) override
	virtual ON_Curve::SetDomain override. Set the domain of the curve More...

bool	SetEndPoint (ON_3dPoint end_point) override
	Force the curve to end at a specified point. More...

bool	SetKnot (int knot_index, double knot_value)
	Set knot value. More...

bool	SetStartPoint (ON_3dPoint start_point) override
	Force the curve to start at a specified point. More...

bool	SetWeight (int, double)
	Set value of control vertex weight. If curve is non-rational, it will be converted to rational. More...

unsigned int	SizeOf () const override
	virtual ON_Object::SizeOf override More...

int	SpanCount () const override
	virtual ON_Curve::SpanCount override. Get number of nonempty smooth (c-infinity) spans in curve More...

bool	SpanIsLinear (int span_index, double min_length, double tolerance) const

bool	SpanIsLinear (int span_index, double min_length, double tolerance, ON_Line *line) const

bool	SpanIsSingular (int span_index) const

bool	Split (double split_param, ON_Curve &left_result, ON_Curve &right_result) const override
	virtual ON_Curve::Split override. More...

double	SuperfluousKnot (int) const

bool	SwapCoordinates (int i, int j) override
	virtual ON_Geometry::SwapCoordinates override. Swaps control vertex coordinate values with indices i and j. More...

bool	Transform (const ON_Xform &xform) override
	virtual ON_Geometry::Transform override. Transforms the NURBS curve. More...

bool	Trim (const ON_Interval &) override
	virtual ON_Curve::Trim override. More...

double	Weight (int) const

bool	Write (ON_BinaryArchive &binary_archive) const override
	virtual ON_Object::Write override More...

bool	ZeroCVs ()

Public Member Functions inherited from ON_Curve
	ON_Curve () ON_NOEXCEPT

	ON_Curve (const ON_Curve &)

virtual	~ON_Curve ()

ON_3dVector	CurvatureAt (double t) const
	Evaluate the curvature vector at a parameter. More...

ON_3dVector	DerivativeAt (double t) const
	Evaluate first derivative at a parameter. More...

void	DestroyCurveTree ()
	Destroys the runtime curve tree used to speed closest point and intersection calcuations. More...

void	DestroyRuntimeCache (bool bDelete=true) override
	virtual ON_Object::DestroyRuntimeCache override More...

virtual ON_Curve *	DuplicateCurve () const
	Get a duplicate of the curve. More...

bool	Ev1Der (double t, ON_3dPoint &point, ON_3dVector &first_derivative, int side=0, int *hint=0) const
	Evaluate first derivative at a parameter with error checking. More...

bool	Ev2Der (double t, ON_3dPoint &point, ON_3dVector &first_derivative, ON_3dVector &second_derivative, int side=0, int *hint=0) const
	Evaluate second derivative at a parameter with error checking. More...

bool	EvaluatePoint (const class ON_ObjRef &objref, ON_3dPoint &P) const override
	virtual ON_Geometry override More...

bool	EvCurvature (double t, ON_3dPoint &point, ON_3dVector &tangent, ON_3dVector &kappa, int side=0, int *hint=0) const
	Evaluate unit tangent and curvature at a parameter with error checking. More...

bool	EvPoint (double t, ON_3dPoint &point, int side=0, int *hint=0) const
	Evaluate point at a parameter with error checking. More...

bool	EvTangent (double t, ON_3dPoint &point, ON_3dVector &tangent, int side=0, int *hint=0) const
	Evaluate unit tangent at a parameter with error checking. More...

bool	FirstSpanIsLinear (double min_length, double tolerance) const

bool	FirstSpanIsLinear (double min_length, double tolerance, ON_Line *span_line) const

bool	FrameAt (double t, ON_Plane &plane) const
	Return a 3d frame at a parameter. More...

bool	GetDomain (double t0, double t1) const
	curve interface More...

virtual bool	GetSpanVectorIndex (double t, int side, int span_vector_index, ON_Interval span_domain) const

bool	GetTightBoundingBox (class ON_BoundingBox &tight_bbox, bool bGrowBox=false, const class ON_Xform *xform=nullptr) const override
	virtual ON_Geometry GetTightBoundingBox override More...

bool	IsArcAt (double t, const ON_Plane plane=0, ON_Arc arc=0, double tolerance=ON_ZERO_TOLERANCE, double t0=0, double t1=0) const

bool	IsClosable (double tolerance, double min_abs_size=0.0, double min_rel_size=10.0) const
	Decide if it makes sense to close off this curve by moving the endpoint to the start based on start-end gap size and length of curve as approximated by chord defined by 6 points. More...

virtual bool	IsEllipse (const ON_Plane plane=nullptr, ON_Ellipse ellipse=nullptr, double tolerance=ON_ZERO_TOLERANCE) const

bool	LastSpanIsLinear (double min_length, double tolerance) const

bool	LastSpanIsLinear (double min_length, double tolerance, ON_Line *span_line) const

ON_NurbsCurve *	NurbsCurve (ON_NurbsCurve pNurbsCurve=nullptr, double tolerance=0.0, const ON_Interval subdomain=nullptr) const
	Get a NURBS curve representation of this curve. More...

ON::object_type	ObjectType () const override
	overrides virtual ON_Object::ObjectType. More...

ON_Curve &	operator= (const ON_Curve &)

ON_3dPoint	PointAt (double t) const
	Evaluate point at a parameter. More...

ON_3dPoint	PointAtEnd () const
	Evaluate point at the end of the curve. More...

ON_3dPoint	PointAtStart () const
	Evaluate point at the start of the curve. More...

bool	SetDomain (ON_Interval domain)
	Set the domain of the curve. More...

ON_3dVector	TangentAt (double t) const
	Evaluate unit tangent vector at a parameter. More...

Public Member Functions inherited from ON_Geometry
	ON_Geometry ()=default

	ON_Geometry (const ON_Geometry &)=default

	~ON_Geometry ()=default

ON_BoundingBox	BoundingBox () const
	Get object's 3d axis aligned bounding box. More...

virtual class ON_Brep *	BrepForm (class ON_Brep *brep=nullptr) const
	If possible, BrepForm() creates a brep form of the ON_Geometry. More...

virtual void	ClearBoundingBox ()
	Some objects cache bounding box information. If you modify an object, then call ClearBoundingBox() to inform the object that any cached bounding boxes are invalid. More...

virtual ON_COMPONENT_INDEX	ComponentIndex () const
	If this piece of geometry is a component in something larger, like an ON_BrepEdge in an ON_Brep, then this function returns the component index. More...

bool	GetBoundingBox (ON_BoundingBox &bbox, bool bGrowBox=false) const
	Get object's 3d axis aligned bounding box or the union of the input box with the object's bounding box. More...

bool	GetBoundingBox (ON_3dPoint &bbox_min, ON_3dPoint &bbox_max, bool bGrowBox=false) const
	Get corners of object's 3d axis aligned bounding box or the union of the input box with the object's bounding box. More...

virtual bool	HasBrepForm () const
	Query an object to see if it has an ON_Brep form. Result: Returns true if the virtual ON_Geometry::BrepForm can compute an ON_Brep representation of this object. More...

ON_Geometry &	operator= (const ON_Geometry &)=default

bool	Rotate (double sin_angle, double cos_angle, const ON_3dVector &rotation_axis, const ON_3dPoint &rotation_center)
	Rotates the object about the specified axis. A positive rotation angle results in a counter-clockwise rotation about the axis (right hand rule). More...

bool	Rotate (double rotation_angle, const ON_3dVector &rotation_axis, const ON_3dPoint &rotation_center)
	Rotates the object about the specified axis. A positive rotation angle results in a counter-clockwise rotation about the axis (right hand rule). More...

bool	Scale (double scale_factor)
	Scales the object by the specified facotor. The scale is centered at the origin. More...

bool	Translate (const ON_3dVector &translation_vector)
	Translates the object along the specified vector. More...

Public Member Functions inherited from ON_Object
	ON_Object () ON_NOEXCEPT

	ON_Object (const ON_Object &)

virtual	~ON_Object ()

virtual ON_AggregateComponentStatus	AggregateComponentStatus () const
	Call whenever a component status setting is modifed by directly changing it on a component in a way that will result in any saved information about the parent object's aggretate component status becoming invalid. More...

bool	AttachUserData (class ON_UserData *pUserData)
	Attach user data to an object. More...

unsigned int	ClearAllComponentStates () const
	Set all active level component states to ON_ComponentStatus::NoneSet. More...

virtual unsigned int	ClearComponentStates (ON_ComponentStatus states_to_clear) const
	Clear the specified states on every component. More...

virtual unsigned int	ClearComponentStates (ON_COMPONENT_INDEX component_index, ON_ComponentStatus states_to_clear) const
	Clear states on an individual component. More...

unsigned int	CopyUserData (const ON_Object &source_object, ON_UUID source_userdata_item_id, ON_Object::UserDataConflictResolution userdata_conflict_resolution)
	Expert user tool that copies user data items with positive values of ON_UserData.m_userdata_copycount from source_object to "this. More...

void	CopyUserData (const ON_Object &source_object)
	Calls CopyUserData(source_object,ON_Object::UserDataConflictResolution::source_object). More...

virtual bool	DeleteComponents (const ON_COMPONENT_INDEX *ci_list, size_t ci_count)
	Delete the portions of the object identified in ci_list[]. More...

bool	DetachUserData (class ON_UserData *pUserData)
	Remove user data from an object. More...

void	EmergencyDestroy ()
	Sets m_user_data_list = 0. More...

class ON_UserData *	FirstUserData () const
	User data is stored as a linked list of ON_UserData classes. FirstUserData gets the first item in the linked list. This is the most recent item attached using AttachUserData(). Remark: To iterate through all the user data on an object, call FirstUserData() and then use ON_UserData::Next() to traverse the list. More...

virtual unsigned int	GetComponentsWithSetStates (ON_ComponentStatus states_filter, bool bAllEqualStates, ON_SimpleArray< ON_COMPONENT_INDEX > &components) const

class ON_UserData *	GetUserData (const ON_UUID &userdata_uuid) const
	Get a pointer to user data. More...

bool	GetUserString (const wchar_t *key, ON_wString &string_value) const
	Get user string from the object. More...

int	GetUserStringKeys (ON_ClassArray< ON_wString > &user_string_keys) const
	Get a list of all user string keys on the object. More...

int	GetUserStrings (ON_ClassArray< ON_UserString > &user_strings) const
	Get a list of all user strings on the object. More...

bool	IsKindOf (const ON_ClassId *pClassId) const
	Low level tool to test if an object is derived from a specified class. More...

virtual void	MarkAggregateComponentStatusAsNotCurrent () const
	Call whenever a component status setting is modifed by directly changing it on a component in a way that will result in any saved information about the parent object's aggretate component status becoming invalid. More...

virtual void	MemoryRelocate ()
	The MemoryRelocate() function is called when an object's location in memory is changed. For example, if an object resides in a chunk of memory that is grown by calling a realloc that has to allocate a new chunk and copy the contents of the old chunk to the new chunk, then the location of the object's memory changes. In practice this happens when classes derived from ON_Object are stored in dynamic arrays, like the default implementation of ON_ObjectArray<>'s that use realloc to grow the dynamic array. More...

virtual ON_UUID	ModelObjectId () const
	All objects in an opennurbs model have an id ( ON_Layer.m_layer_id, ON_Font.m_font_id, ON_Material.m_material_id, ON_3dmObjectAttributes.m_uuid ). More...

unsigned int	MoveUserData (ON_Object &source_object, ON_UUID source_userdata_item_id, ON_Object::UserDataConflictResolution userdata_conflict_resolution, bool bDeleteAllSourceItems)
	Expert user tool that moves user data items from source_object to "this. More...

void	MoveUserData (ON_Object &source_object)
	Calls MoveUserData(source_object,ON_Object::UserDataConflictResolution::source_object,true). More...

ON_Object &	operator= (const ON_Object &)

void	PurgeUserData ()
	PurgeUserData() removes all user data from object. More...

virtual unsigned int	SetComponentStates (ON_COMPONENT_INDEX component_index, ON_ComponentStatus states_to_set) const
	Set states on an individual component. More...

virtual unsigned int	SetComponentStatus (ON_COMPONENT_INDEX component_index, ON_ComponentStatus status_to_copy) const
	Copy status settings to an individual component. More...

bool	SetUserString (const wchar_t key, const wchar_t string_value)
	Attach a user string to the object. This information will perisist through copy construction, operator=, and file IO. More...

int	SetUserStrings (int count, const ON_UserString *user_strings, bool bReplace)
	Append entries to the user string list More...

void	TransformUserData (const class ON_Xform &xform)
	Objects derived from ON_Geometry must call TransformUserData() in their Transform() member function. More...

virtual bool	UpdateReferencedComponents (const class ON_ComponentManifest &source_manifest, const class ON_ComponentManifest &destination_manifest, const class ON_ManifestMap &manifest_map)
	Uses the destination_manifest to update references to other components. This is typically done when a component's references came from a "source" context and are being updated to the "destination" context. For example, inserting one model into another when index, id, and name conflicts need to be resolved at the time of insertion. More...

int	UserStringCount () const

Static Public Member Functions
static ON_NurbsCurve *	New ()
	Use ON_NurbsCurve::New(...) instead of new ON_NurbsCurve(...) More...

static ON_NurbsCurve *	New (const ON_NurbsCurve &nurbs_curve)

static ON_NurbsCurve *	New (const ON_BezierCurve &bezier_curve)

static ON_NurbsCurve *	New (int dimension, bool bIsRational, int order, int cv_count)

Public Attributes
double *	m_cv

int	m_cv_capacity

int	m_cv_count

int	m_cv_stride
	control vertex net memory More...

int	m_dim
	Implementation. More...

int	m_is_rat

double *	m_knot

int	m_knot_capacity
	knot vector memory More...

int	m_order

Additional Inherited Members
Public Types inherited from ON_Object
enum	UserDataConflictResolution : unsigned char { UserDataConflictResolution::destination_object = 0, UserDataConflictResolution::source_object = 1, UserDataConflictResolution::source_copycount_gt = 2, UserDataConflictResolution::source_copycount_ge = 3, UserDataConflictResolution::destination_copycount_gt = 4, UserDataConflictResolution::destination_copycount_ge = 5, UserDataConflictResolution::delete_item = 6 }
	When a userdata item is copied or moved from a source object to a destination object, the ON_Object::UserDataConflictResolution enum values specify how conficts are resolved. Remark: A userdata item "conflict" occurs when both the destination and source object have a user data item with the same value of ON_UserData::m_userdata_uuid. More...

Static Public Attributes inherited from ON_Geometry
static const ON_Geometry	Unset

Protected Member Functions inherited from ON_Curve
bool	ParameterSearch (double t, int &index, bool bEnableSnap, const ON_SimpleArray< double > &m_t, double RelTol=ON_SQRT_EPSILON) const
	Lookup a parameter in the m_t array, optionally using a built in snap tolerance to snap a parameter value to an element of m_t. This function is used by some types derived from ON_Curve to snap parameter values More...

Constructor & Destructor Documentation

◆ ON_NurbsCurve() [1/4]

ON_NurbsCurve::ON_NurbsCurve ( )

◆ ~ON_NurbsCurve()

virtual ON_NurbsCurve::~ON_NurbsCurve ( )

virtual

◆ ON_NurbsCurve() [2/4]

ON_NurbsCurve::ON_NurbsCurve ( const ON_NurbsCurve & )

◆ ON_NurbsCurve() [3/4]

ON_NurbsCurve::ON_NurbsCurve ( const ON_BezierCurve & bezier_curve )

Create a NURBS curve equal to bezier with domain [0,1].

Parameters

bezier_curve [in]

◆ ON_NurbsCurve() [4/4]

ON_NurbsCurve::ON_NurbsCurve	(	int	dimension,
		bool	bIsRational,
		int	order,
		int	cv_count
	)

Create a NURBS curve with knot a cv memory allocated.

Parameters

dimension	[in] (>= 1)
bIsRational	[in] true to make a rational NURBS
order	[in] (>= 2) The order=degree+1
cv_count	[in] (>= order) number of control vertices

Member Function Documentation

◆ Append()

bool ON_NurbsCurve::Append ( const ON_NurbsCurve & )

◆ ChangeClosedCurveSeam()

bool ON_NurbsCurve::ChangeClosedCurveSeam ( double t )

overridevirtual

If this curve is closed, then modify it so that the start/end point is at curve parameter t.

Parameters

t	[in] curve parameter of new start/end point. The returned curves domain will start at t.

Returns: true if successful.

Overrides virtual ON_Curve::ChangeClosedCurveSeam

Reimplemented from ON_Curve.

◆ ChangeDimension()

bool ON_NurbsCurve::ChangeDimension ( int desired_dimension )

overridevirtual

Change the dimension of a curve.

Parameters

desired_dimension [in]

Returns: true if the curve's dimension was already desired_dimension or if the curve's dimension was successfully changed to desired_dimension.

Reimplemented from ON_Curve.

◆ ChangeEndWeights()

bool ON_NurbsCurve::ChangeEndWeights	(	double	w0,
		double	w1
	)

Use a combination of scaling and reparameterization to change the end weights to the specified values.

Parameters

w0	[in] weight for first cv
w1	[in] weight for last cv

Returns: true if successful.

The domain, eucleanean locations of the control points, and locus of the curve do not change, but the weights, homogeneous cv values and internal knot values may change. If w0 and w1 are 1 and the curve is not rational, the curve is not changed.

See also: ON_ChangeRationalNurbsCurveEndWeights

◆ ClampEnd()

bool ON_NurbsCurve::ClampEnd ( int end )

Clamp end knots. Does not modify control points.

Parameters

end	[in] 0 = clamp start, 1 = clamp end, 2 = clamp start and end

Returns: true if successful

◆ ControlPoint()

const ON_4dPoint ON_NurbsCurve::ControlPoint ( int cv_index ) const

Parameters

cv_index [in] zero based control point index

Returns: Control point as an ON_4dPoint.

If cv_index or the nurbs curve is not valid, then ON_4dPoint::Nan is returned. If dim < 3, unused coordinates are zero. If dim >= 4, the first three coordinates are returned. If is_rat is false, the weight is 1.

◆ ControlPolygonLength()

double ON_NurbsCurve::ControlPolygonLength ( ) const

returns the length of the control polygon

◆ ConvertSpanToBezier()

bool ON_NurbsCurve::ConvertSpanToBezier	(	int	,
		ON_BezierCurve &
	)		const

◆ Create()

bool ON_NurbsCurve::Create	(	int	dimension,
		bool	bIsRational,
		int	order,
		int	cv_count
	)

Create a NURBS curve with knot a cv memory allocated.

Parameters

dimension	[in] (>= 1)
bIsRational	[in] true to make a rational NURBS
order	[in] (>= 2) The order=degree+1
cv_count	[in] (>= order) number of control vertices

◆ CreateClampedUniformNurbs()

bool ON_NurbsCurve::CreateClampedUniformNurbs	(	int	dimension,
		int	order,
		int	point_count,
		const ON_3dPoint *	point,
		double	knot_delta = `1.0`
	)

Create a clamped uniform NURBS curve from a list of control points

Parameters

dimension	[in] 1, 2 or 3
order	[in] (>=2) order=degree+1
point_count	[in] (>=order) number of control vertices
point	[in] array of control vertex locations.
knot_delta	in knot spacing

Returns: true if successful

◆ CreatePeriodicUniformNurbs()

bool ON_NurbsCurve::CreatePeriodicUniformNurbs	(	int	dimension,
		int	order,
		int	point_count,
		const ON_3dPoint *	point,
		double	knot_delta = `1.0`
	)

Create a periodic uniform NURBS curve from a list of control points

Parameters

dimension	[in] 1, 2 or 3
order	[in] (>=2) order=degree+1
point_count	[in] (>=max(3,order-1)) number of distinct control vertices
point	[in] array of distinct control vertex locations.
knot_delta	in knot spacing

Returns: true if successful

◆ CV()

double* ON_NurbsCurve::CV ( int cv_index ) const

Expert user function to get a pointer to control vertex memory. If you are not an expert user, please use ON_NurbsCurve::GetCV( ON_3dPoint& ) or ON_NurbsCurve::GetCV( ON_4dPoint& ).

Parameters

cv_index [in]

Returns: Pointer to control vertex.

If the NURBS curve is rational, the format of the returned array is a homogeneos rational point with length m_dim+1. If the NURBS curve is not rational, the format of the returned array is a nonrational euclidean point with length m_dim. See Also ON_NurbsCurve::CVStyle ON_NurbsCurve::GetCV ON_NurbsCurve::Weight

◆ CVCount()

int ON_NurbsCurve::CVCount ( void ) const

◆ CVSize()

int ON_NurbsCurve::CVSize ( void ) const

◆ CVStyle()

ON::point_style ON_NurbsCurve::CVStyle ( ) const

Returns the style of control vertices in the m_cv array.

Returns: table ON::not_rational m_is_rat is false ON::homogeneous_rational m_is_rat is true

◆ DataCRC()

ON__UINT32 ON_NurbsCurve::DataCRC ( ON__UINT32 current_remainder ) const

overridevirtual

virtual ON_Object::DataCRC override

Reimplemented from ON_Object.

◆ Degree()

int ON_NurbsCurve::Degree ( ) const

overridevirtual

virtual ON_Curve::Degree override.

Returns: m_order-1

Implements ON_Curve.

◆ Destroy()

void ON_NurbsCurve::Destroy ( )

Deallocate knot and cv memory. Zeros all fields.

◆ Dimension()

int ON_NurbsCurve::Dimension ( ) const

overridevirtual

ON_Geometry overrides.

virtual ON_Geometry::Dimension override

Returns: value of m_dim

Reimplemented from ON_Geometry.

◆ Domain()

ON_Interval ON_NurbsCurve::Domain ( ) const

overridevirtual

ON_Curve overrides.

virtual ON_Curve::Domain override.

Returns: domain of the NURBS curve.

Implements ON_Curve.

◆ Dump()

void ON_NurbsCurve::Dump ( ON_TextLog & dump ) const

overridevirtual

virtual ON_Object::Dump override

Reimplemented from ON_Object.

◆ EmergencyDestroy()

void ON_NurbsCurve::EmergencyDestroy ( )

Call if memory used by ON_NurbsCurve becomes invalid.

◆ Evaluate()

bool ON_NurbsCurve::Evaluate	(	double	,
		int	,
		int	,
		double *	,
		int	= `0`,
		int *	= `0`
	)		const

overridevirtual

virtual ON_Curve::Evaluate override.

Implements ON_Curve.

◆ Extend()

bool ON_NurbsCurve::Extend ( const ON_Interval & domain )

overridevirtual

Where possible, analytically extends curve to include domain.

Parameters

domain [in] if domain is not included in curve domain, curve will be extended so that its domain includes domain. Will not work if curve is closed. Original curve is identical to the restriction of the resulting curve to the original curve domain,

Returns: true if successful.

Reimplemented from ON_Curve.

◆ GetBBox()

bool ON_NurbsCurve::GetBBox	(	double *	boxmin,
		double *	boxmax,
		bool	bGrowBox = `false`
	)		const

overridevirtual

virtual ON_Geometry GetBBox override

Reimplemented from ON_Geometry.

◆ GetCurveParameterFromNurbFormParameter()

bool ON_NurbsCurve::GetCurveParameterFromNurbFormParameter	(	double	nurbs_t,
		double *	curve_t
	)		const

overridevirtual

virtual ON_Curve::GetCurveParameterFromNurbFormParameter override

Reimplemented from ON_Curve.

◆ GetCV() [1/3]

bool ON_NurbsCurve::GetCV	(	int	,
		ON::point_style	,
		double *
	)		const

◆ GetCV() [2/3]

bool ON_NurbsCurve::GetCV	(	int	,
		ON_3dPoint &
	)		const

◆ GetCV() [3/3]

bool ON_NurbsCurve::GetCV	(	int	,
		ON_4dPoint &
	)		const

◆ GetGrevilleAbcissae()

bool ON_NurbsCurve::GetGrevilleAbcissae ( double * ) const

◆ GetNextDiscontinuity()

bool ON_NurbsCurve::GetNextDiscontinuity	(	ON::continuity	c,
		double	t0,
		double	t1,
		double *	t,
		int *	hint = `nullptr`,
		int *	dtype = `nullptr`,
		double	cos_angle_tolerance = `ON_DEFAULT_ANGLE_TOLERANCE_COSINE`,
		double	curvature_tolerance = `ON_SQRT_EPSILON`
	)		const

overridevirtual

Search for a derivatitive, tangent, or curvature discontinuity.

Parameters

c	[in] type of continity to test for. If ON::continuity::C1_continuous
t0	[in] search begins at t0
t1	[in] (t0 < t1) search ends at t1
t	[out] if a discontinuity is found, the *t reports the parameter at the discontinuity.
hint	[in/out] if GetNextDiscontinuity will be called repeatedly, passing a "hint" with initial value *hint=0 will increase the speed of the search.
dtype	[out] if not nullptr, dtype reports the kind of discontinuity found at t. A value of 1 means the first derivative or unit tangent was discontinuous. A value of 2 means the second derivative or curvature was discontinuous.
cos_angle_tolerance	[in] default = cos(1 degree) Used only when c is ON::continuity::G1_continuous or ON::continuity::G2_continuous. If the cosine of the angle between two tangent vectors is <= cos_angle_tolerance, then a G1 discontinuity is reported.
curvature_tolerance	[in] (default = ON_SQRT_EPSILON) Used only when c is ON::continuity::G2_continuous or ON::continuity::Gsmooth_continuous. ON::continuity::G2_continuous: If K0 and K1 are curvatures evaluated from above and below and \|K0 - K1\| > curvature_tolerance, then a curvature discontinuity is reported. ON::continuity::Gsmooth_continuous: If K0 and K1 are curvatures evaluated from above and below and the angle between K0 and K1 is at least twice angle tolerance or \|\|K0\| - \|K1\|\| > (max(\|K0\|,\|K1\|) > curvature_tolerance, then a curvature discontinuity is reported.

Returns: true if a discontinuity was found on the interior of the interval (t0,t1).

Overrides ON_Curve::GetNextDiscontinuity.

Reimplemented from ON_Curve.

◆ GetNurbForm()

int ON_NurbsCurve::GetNurbForm	(	ON_NurbsCurve &	nurbsform,
		double	tolerance = `0.0`,
		const ON_Interval *	subdomain = `nullptr`
	)		const

overridevirtual

virtual ON_Curve::GetNurbForm override.

Reimplemented from ON_Curve.

◆ GetNurbFormParameterFromCurveParameter()

bool ON_NurbsCurve::GetNurbFormParameterFromCurveParameter	(	double	curve_t,
		double *	nurbs_t
	)		const

overridevirtual

virtual ON_Curve::GetNurbFormParameterFromCurveParameter override

Reimplemented from ON_Curve.

◆ GetParameterTolerance()

bool ON_NurbsCurve::GetParameterTolerance	(	double	t,
		double *	tminus,
		double *	tplus
	)		const

overridevirtual

virtual ON_Curve::GetParameterTolerance override.

Reimplemented from ON_Curve.

◆ GetSpanVector()

bool ON_NurbsCurve::GetSpanVector ( double * knot_values ) const

overridevirtual

virtual ON_Curve::GetSpanVector override. Get number of parameters of distinct knots in NURBS curve's domain.

Parameters

knot_values [out] an array of length SpanCount()+1 is filled in with the distinct knot values in the list

(m_knot[m_order-2],...,m_knot[m_cv_count-1)

Returns: true if successful

Implements ON_Curve.

◆ GrevilleAbcissa()

double ON_NurbsCurve::GrevilleAbcissa ( int ) const

◆ HasBezierSpans()

bool ON_NurbsCurve::HasBezierSpans ( ) const

◆ HasNurbForm()

int ON_NurbsCurve::HasNurbForm ( ) const

overridevirtual

virtual ON_Curve::HasNurbForm override.

Reimplemented from ON_Curve.

◆ IncreaseDegree()

bool ON_NurbsCurve::IncreaseDegree ( int desired_degree )

◆ Initialize()

void ON_NurbsCurve::Initialize ( void )

Zeros all fields.

◆ InsertKnot()

bool ON_NurbsCurve::InsertKnot	(	double	knot_value,
		int	knot_multiplicity
	)

Insert a knot and update cv locations.

Parameters

knot_value	[in] m_knot[order-2] < knot_value < m_knot[m_cv_count-1]
knot_multiplicity	[in] 1 to degree - includes multiplicity of existing knots.

Returns: true if successful

Does not change parameterization or locus of curve.

◆ IsArc()

bool ON_NurbsCurve::IsArc	(	const ON_Plane *	plane = `nullptr`,
		ON_Arc *	arc = `nullptr`,
		double	tolerance = `ON_ZERO_TOLERANCE`
	)		const

overridevirtual

virtual ON_Curve::IsArc override.

Reimplemented from ON_Curve.

◆ IsClamped()

bool ON_NurbsCurve::IsClamped ( int = 2 ) const

◆ IsClosed()

bool ON_NurbsCurve::IsClosed ( ) const

overridevirtual

virtual ON_Curve::IsClosed override.

Returns: true if NURBS curve is closed. (Either curve has clamped end knots and euclidean location of start CV = euclidean location of end CV, or curve is periodic.)

Reimplemented from ON_Curve.

◆ IsContinuous()

bool ON_NurbsCurve::IsContinuous	(	ON::continuity	c,
		double	t,
		int *	hint = `nullptr`,
		double	point_tolerance = `ON_ZERO_TOLERANCE`,
		double	d1_tolerance = `ON_ZERO_TOLERANCE`,
		double	d2_tolerance = `ON_ZERO_TOLERANCE`,
		double	cos_angle_tolerance = `ON_DEFAULT_ANGLE_TOLERANCE_COSINE`,
		double	curvature_tolerance = `ON_SQRT_EPSILON`
	)		const

overridevirtual

Test continuity at a curve parameter value.

Parameters

c	[in] continuity to test for
t	[in] parameter to test
hint	[in] evaluation hint
point_tolerance	[in] if the distance between two points is greater than point_tolerance, then the curve is not C0.
d1_tolerance	[in] if the difference between two first derivatives is greater than d1_tolerance, then the curve is not C1.
d2_tolerance	[in] if the difference between two second derivatives is greater than d2_tolerance, then the curve is not C2.
cos_angle_tolerance	[in] default = cos(1 degree) Used only when c is ON::continuity::G1_continuous or ON::continuity::G2_continuous. If the cosine of the angle between two tangent vectors is <= cos_angle_tolerance, then a G1 discontinuity is reported.
curvature_tolerance	[in] (default = ON_SQRT_EPSILON) Used only when c is ON::continuity::G2_continuous or ON::continuity::Gsmooth_continuous. ON::continuity::G2_continuous: If K0 and K1 are curvatures evaluated from above and below and \|K0 - K1\| > curvature_tolerance, then a curvature discontinuity is reported. ON::continuity::Gsmooth_continuous: If K0 and K1 are curvatures evaluated from above and below and the angle between K0 and K1 is at least twice angle tolerance or \|\|K0\| - \|K1\|\| > (max(\|K0\|,\|K1\|) > curvature_tolerance, then a curvature discontinuity is reported.

Returns: true if the curve has at least the c type continuity at the parameter t.

Overrides ON_Curve::IsContinuous.

Reimplemented from ON_Curve.

◆ IsDeformable()

bool ON_NurbsCurve::IsDeformable ( ) const

overridevirtual

virtual ON_Geometry::IsDeformable() override

Reimplemented from ON_Geometry.

◆ IsDuplicate()

bool ON_NurbsCurve::IsDuplicate	(	const ON_NurbsCurve &	other,
		bool	bIgnoreParameterization,
		double	tolerance = `ON_ZERO_TOLERANCE`
	)		const

See if this and other are same NURBS geometry.

Parameters

other	[in] other NURBS curve
bIgnoreParameterization	[in] if true, parameterization and orientaion are ignored.
tolerance	[in] tolerance to use when comparing control points.

Returns: true if curves are tne same.

◆ IsInPlane()

bool ON_NurbsCurve::IsInPlane	(	const ON_Plane &	test_plane,
		double	tolerance = `ON_ZERO_TOLERANCE`
	)		const

overridevirtual

virtual ON_Curve::IsInPlane override.

Implements ON_Curve.

◆ IsLinear()

bool ON_NurbsCurve::IsLinear ( double tolerance = ON_ZERO_TOLERANCE ) const

overridevirtual

virtual ON_Curve::IsLinear override.

Reimplemented from ON_Curve.

◆ IsPeriodic()

bool ON_NurbsCurve::IsPeriodic ( ) const

overridevirtual

virtual ON_Curve::IsPeriodic override.

Returns: true if NURBS curve is periodic (degree > 1, periodic knot vector, last degree many CVs are duplicates of first degree many CVs).

Reimplemented from ON_Curve.

◆ IsPlanar()

bool ON_NurbsCurve::IsPlanar	(	ON_Plane *	plane = `nullptr`,
		double	tolerance = `ON_ZERO_TOLERANCE`
	)		const

overridevirtual

virtual ON_Curve::IsPlanar override.

Reimplemented from ON_Curve.

◆ IsPolyline()

int ON_NurbsCurve::IsPolyline	(	ON_SimpleArray< ON_3dPoint > *	pline_points = `nullptr`,
		ON_SimpleArray< double > *	pline_t = `nullptr`
	)		const

overridevirtual

Several types of ON_Curve can have the form of a polyline including a degree 1 ON_NurbsCurve, an ON_PolylineCurve, and an ON_PolyCurve all of whose segments are some form of polyline. IsPolyline tests a curve to see if it can be represented as a polyline.

Parameters

pline_points	[out] if not nullptr and true is returned, then the points of the polyline form are returned here.
t	[out] if not nullptr and true is returned, then the parameters of the polyline points are returned here.

Returns: table 0 curve is not some form of a polyline >=2 number of points in polyline form

Reimplemented from ON_Curve.

◆ IsRational()

bool ON_NurbsCurve::IsRational ( void ) const

Interface.

◆ IsSingular()

bool ON_NurbsCurve::IsSingular ( ) const

Returns: True if every span in the NURBS curve is singular.

See also: ON_NurbsCurve::RepairBadKnots(), ON_NurbsCurve::RemoveShortSegments()

◆ IsValid()

bool ON_NurbsCurve::IsValid ( class ON_TextLog * text_log = nullptr ) const

overridevirtual

ON_Object overrides.

Reimplemented from ON_Geometry.

◆ Knot() [1/2]

double ON_NurbsCurve::Knot ( int knot_index ) const

Get knot value.

Parameters

knot_index [in] 0 <= knot_index <= KnotCount()-1

Returns: knot value = m_knot[knot_index]

See also: ON_NurbsCurve::SetKnot, ON_NurbsCurve::KnotMultiplicity

◆ Knot() [2/2]

const double* ON_NurbsCurve::Knot ( ) const

Get pointer to knot vector array.

Returns: pointer to knot vector array (m_knot).

See also: ON_NurbsCurve::SetKnot, ON_NurbsCurve::Knot,, ON_NurbsCurve::InsertKnot

◆ KnotCount()

int ON_NurbsCurve::KnotCount ( void ) const

◆ KnotMultiplicity()

int ON_NurbsCurve::KnotMultiplicity ( int knot_index ) const

Get knot multiplicity.

Parameters

knot_index [in] 0 <= knot_index <= KnotCount()-1

Returns: knot multiplicity = m_knot[knot_index]

See also: ON_NurbsCurve::SetKnot, ON_NurbsCurve::Knot,, ON_NurbsCurve::InsertKnot

◆ MakeClampedUniformKnotVector()

bool ON_NurbsCurve::MakeClampedUniformKnotVector ( double delta = 1.0 )

Make knot vector a clamped uniform knot vector based on the current values of m_order and m_cv_count. Does not change values of control vertices.

Parameters

delta in knot spacing.

Returns: true if successful.

Allocates m_knot[] if it is not big enough.

See also: ON_MakeClampedUniformKnotVector

◆ MakeDeformable()

bool ON_NurbsCurve::MakeDeformable ( )

overridevirtual

virtual ON_Geometry::MakeDeformable() override

Reimplemented from ON_Geometry.

◆ MakeNonRational()

bool ON_NurbsCurve::MakeNonRational ( )

◆ MakePeriodicUniformKnotVector()

bool ON_NurbsCurve::MakePeriodicUniformKnotVector ( double delta = 1.0 )

Make knot vector a periodic uniform knot vector based on the current values of m_order and m_cv_count. Does not change values of control vertices.

Parameters

delta in knot spacing.

Returns: true if successful.

Allocates m_knot[] if it is not big enough.

See also: ON_MakePeriodicUniformKnotVector

◆ MakePiecewiseBezier()

bool ON_NurbsCurve::MakePiecewiseBezier ( bool bSetEndWeightsToOne = false )

Clamps ends and adds knots so the NURBS curve has bezier spans (all distinct knots have multiplitity = degree). Paremeters: bSetEndWeightsToOne - [in] If true and the first or last weight is not one, then the first and last spans are reparameterized so that the end weights are one.

Returns: true if successful.

◆ MakeRational()

bool ON_NurbsCurve::MakeRational ( )

◆ New() [1/4]

static ON_NurbsCurve* ON_NurbsCurve::New ( )

static

Use ON_NurbsCurve::New(...) instead of new ON_NurbsCurve(...)

Returns: Pointer to an ON_NurbsCurve. Destroy by calling delete.

See static ON_Brep* ON_Brep::New() for details.

◆ New() [2/4]

static ON_NurbsCurve* ON_NurbsCurve::New ( const ON_NurbsCurve & nurbs_curve )

static

◆ New() [3/4]

static ON_NurbsCurve* ON_NurbsCurve::New ( const ON_BezierCurve & bezier_curve )

static

◆ New() [4/4]

static ON_NurbsCurve* ON_NurbsCurve::New	(	int	dimension,
		bool	bIsRational,
		int	order,
		int	cv_count
	)

static

◆ operator=() [1/2]

ON_NurbsCurve& ON_NurbsCurve::operator= ( const ON_NurbsCurve & src )

◆ operator=() [2/2]

ON_NurbsCurve& ON_NurbsCurve::operator= ( const ON_BezierCurve & bezier_curve )

Set NURBS curve equal to bezier with domain [0,1].

Parameters

bezier_curve [in]

◆ Order()

int ON_NurbsCurve::Order ( void ) const

◆ Read()

bool ON_NurbsCurve::Read ( ON_BinaryArchive & binary_archive )

overridevirtual

virtual ON_Object::Read override

Reimplemented from ON_Object.

◆ RemoveSingularSpans()

int ON_NurbsCurve::RemoveSingularSpans ( )

Returns: Number of spans removed.

◆ RemoveSpan()

bool ON_NurbsCurve::RemoveSpan ( int span_index )

Returns: True if the span was successfully removed.

The NURBS curve must have 2 or more spans (m_cv_count > m_order). Set m0 = mulitiplicity of the knot at m_knot[span_index+m_order-2] and m1 = mulitiplicity of the knot at m_knot[span_index+m_order-1]. If (m0 + m1) < degree, then the degree-(m0+m1) cvs will be added to the NURBS curve. If (m0+m1) > degree, then (m0+m1)-degree cvs will be removed from the curve.

See also: ON_NurbsCurve::RepairBadKnots(), ON_NurbsCurve::RemoveShortSegments()

◆ RepairBadKnots()

bool ON_NurbsCurve::RepairBadKnots	(	double	knot_tolerance = `0.0`,
		bool	bRepair = `true`
	)

Looks for problems caused by knots that are close together or have mulitplicity >= order. If bRepair is true, the problems are fixed. Does not change the domain.

Parameters

knot_tolerance	[in] >= 0 When in doubt, use zero.
bRepair	[in] If true, then problems are repaired. Otherwise this function looks for problemsn that can be repaired, but does not modify the curve.

Returns: True if bad knots were found and can be repaired.

See also: ON_NurbsCurve::RemoveShortSegments

◆ Reparameterize()

bool ON_NurbsCurve::Reparameterize ( double c )

Use a linear fractional transformation to reparameterize the NURBS curve. This does not change the curve's domain.

Parameters

c	[in] reparameterization constant (generally speaking, c should be > 0). The control points and knots are adjusted so that output_nurbs(t) = input_nurbs(lambda(t)), where lambda(t) = ct/( (c-1)t + 1 ). Note that lambda(0) = 0, lambda(1) = 1, lambda'(t) > 0, lambda'(0) = c and lambda'(1) = 1/c.

Returns: true if successful.

The cv and knot values are values are changed so that output_nurbs(t) = input_nurbs(lambda(t)).

See also: ON_ReparameterizeRationalNurbsCurve

◆ ReserveCVCapacity()

bool ON_NurbsCurve::ReserveCVCapacity ( int )

Tools for managing CV and knot memory.

◆ ReserveKnotCapacity()

bool ON_NurbsCurve::ReserveKnotCapacity ( int )

◆ Reverse()

bool ON_NurbsCurve::Reverse ( )

overridevirtual

virtual ON_Curve::Reverse override. Reverse parameterizatrion by negating all knots and reversing the order of the control vertices.

Domain changes from [a,b] to [-b,-a]

Implements ON_Curve.

◆ SetCV() [1/3]

bool ON_NurbsCurve::SetCV	(	int	,
		ON::point_style	,
		const double *
	)

◆ SetCV() [2/3]

bool ON_NurbsCurve::SetCV	(	int	,
		const ON_3dPoint &
	)

◆ SetCV() [3/3]

bool ON_NurbsCurve::SetCV	(	int	,
		const ON_4dPoint &
	)

◆ SetDomain()

bool ON_NurbsCurve::SetDomain	(	double	t0,
		double	t1
	)

overridevirtual

virtual ON_Curve::SetDomain override. Set the domain of the curve

Parameters

t0	[in]
t1	[in] new domain will be [t0,t1]

Returns: true if successful.

Reimplemented from ON_Curve.

◆ SetEndPoint()

bool ON_NurbsCurve::SetEndPoint ( ON_3dPoint end_point )

overridevirtual

Force the curve to end at a specified point.

Parameters

end_point [in]

Returns: true if successful.

Some end points cannot be moved. Be sure to check return code.

See also: ON_Curve::SetStartPoint, ON_Curve::PointAtStart, ON_Curve::PointAtEnd

virtual

Reimplemented from ON_Curve.

◆ SetKnot()

bool ON_NurbsCurve::SetKnot	(	int	knot_index,
		double	knot_value
	)

Set knot value.

Parameters

knot_index	[in] 0 <= knot_index <= KnotCount()-1
knot_value	[in]

Returns: true if successful

m_knot[] must exist. Use ReserveKnotCapacity to allocate m_knot[].

See also: ON_NurbsCurve::ReserveKnotCapacity

◆ SetStartPoint()

bool ON_NurbsCurve::SetStartPoint ( ON_3dPoint start_point )

overridevirtual

Force the curve to start at a specified point.

Parameters

start_point [in]

Returns: true if successful.

Some end points cannot be moved. Be sure to check return code.

See also: ON_Curve::SetEndPoint, ON_Curve::PointAtStart, ON_Curve::PointAtEnd

virtual

Reimplemented from ON_Curve.

◆ SetWeight()

bool ON_NurbsCurve::SetWeight	(	int	,
		double
	)

Set value of control vertex weight. If curve is non-rational, it will be converted to rational.

◆ SizeOf()

unsigned int ON_NurbsCurve::SizeOf ( ) const

overridevirtual

virtual ON_Object::SizeOf override

Reimplemented from ON_Curve.

◆ SpanCount()

int ON_NurbsCurve::SpanCount ( ) const

overridevirtual

virtual ON_Curve::SpanCount override. Get number of nonempty smooth (c-infinity) spans in curve

Returns: Number of nonempty smooth (c-infinity) spans.

A nonempty span is bracked by knots m_knot[i] < m_knot[i+1] with m_order-2 <= i < m_cv_count-1.

Implements ON_Curve.

◆ SpanIsLinear() [1/2]

bool ON_NurbsCurve::SpanIsLinear	(	int	span_index,
		double	min_length,
		double	tolerance
	)		const

Parameters

span_index	[in] (0 <= span_index <= m_cv_count-m_order)
min_length	[in] minimum length of a linear span
tolerance	[in] distance tolerance to use when checking control points between the span ends Returns true if the span is a non-degenrate line. This means: dimension = 2 or 3 There are full multiplicity knots at each end of the span. The length of the the line segment from the span's initial control point to the span's final control point is >= min_length. The distance from the line segment to the interior control points is <= tolerance and the projections of these points onto the line increases monotonically.

◆ SpanIsLinear() [2/2]

bool ON_NurbsCurve::SpanIsLinear	(	int	span_index,
		double	min_length,
		double	tolerance,
		ON_Line *	line
	)		const

◆ SpanIsSingular()

bool ON_NurbsCurve::SpanIsSingular ( int span_index ) const

Returns: true if the span_index parameter is valid and the span is singular (collapsed to a point). false if the span is not singular or span_index does not identify a non-empty span.

◆ Split()

bool ON_NurbsCurve::Split	(	double	split_param,
		ON_Curve *&	left_result,
		ON_Curve *&	right_result
	)		const

overridevirtual

virtual ON_Curve::Split override.

Split() divides the curve at the specified parameter. The parameter must be in the interior of the curve's domain. The pointers passed to ON_NurbsCurve::Split must either be nullptr or point to an ON_NurbsCurve. If the pointer is nullptr, then a curve will be created in Split(). You may pass "this" as one of the pointers to Split(). For example,

ON_NurbsCurve right_side; crv.Split( crv.Domain().Mid() &crv, &right_side );

would split crv at the parametric midpoint, put the left side in crv, and return the right side in right_side.

Reimplemented from ON_Curve.

◆ SuperfluousKnot()

double ON_NurbsCurve::SuperfluousKnot ( int ) const

◆ SwapCoordinates()

bool ON_NurbsCurve::SwapCoordinates	(	int	i,
		int	j
	)

overridevirtual

virtual ON_Geometry::SwapCoordinates override. Swaps control vertex coordinate values with indices i and j.

Parameters

i	[in] coordinate index
j	[in] coordinate index

Reimplemented from ON_Geometry.

◆ Transform()

bool ON_NurbsCurve::Transform ( const ON_Xform & xform )

overridevirtual

virtual ON_Geometry::Transform override. Transforms the NURBS curve.

Parameters

xform [in] transformation to apply to object.

When overriding this function, be sure to include a call to ON_Object::TransformUserData() which takes care of transforming any ON_UserData that may be attached to the object.

Reimplemented from ON_Curve.

◆ Trim()

bool ON_NurbsCurve::Trim ( const ON_Interval & )

overridevirtual

virtual ON_Curve::Trim override.

Reimplemented from ON_Curve.

◆ Weight()

double ON_NurbsCurve::Weight ( int ) const

◆ Write()

bool ON_NurbsCurve::Write ( ON_BinaryArchive & binary_archive ) const

overridevirtual

virtual ON_Object::Write override

Reimplemented from ON_Object.

◆ ZeroCVs()

bool ON_NurbsCurve::ZeroCVs ( )

Member Data Documentation

◆ m_cv

double* ON_NurbsCurve::m_cv

◆ m_cv_capacity

int ON_NurbsCurve::m_cv_capacity

◆ m_cv_count

int ON_NurbsCurve::m_cv_count

◆ m_cv_stride

int ON_NurbsCurve::m_cv_stride

control vertex net memory

◆ m_dim

int ON_NurbsCurve::m_dim

Implementation.

◆ m_is_rat

int ON_NurbsCurve::m_is_rat

◆ m_knot

double* ON_NurbsCurve::m_knot

◆ m_knot_capacity

int ON_NurbsCurve::m_knot_capacity

knot vector memory

◆ m_order

int ON_NurbsCurve::m_order

Public Member Functions

Static Public Member Functions

Public Attributes

Additional Inherited Members

Constructor & Destructor Documentation

◆ ON_NurbsCurve() [1/4]

◆ ~ON_NurbsCurve()

◆ ON_NurbsCurve() [2/4]

◆ ON_NurbsCurve() [3/4]

◆ ON_NurbsCurve() [4/4]

Member Function Documentation

◆ Append()

◆ ChangeClosedCurveSeam()

◆ ChangeDimension()

◆ ChangeEndWeights()

◆ ClampEnd()

◆ ControlPoint()

◆ ControlPolygonLength()

◆ ConvertSpanToBezier()

◆ Create()

◆ CreateClampedUniformNurbs()

◆ CreatePeriodicUniformNurbs()

◆ CV()

◆ CVCount()

◆ CVSize()

◆ CVStyle()

◆ DataCRC()

◆ Degree()

◆ Destroy()

◆ Dimension()

◆ Domain()

◆ Dump()

◆ EmergencyDestroy()

◆ Evaluate()

◆ Extend()

◆ GetBBox()

◆ GetCurveParameterFromNurbFormParameter()

◆ GetCV() [1/3]

◆ GetCV() [2/3]

◆ GetCV() [3/3]

◆ GetGrevilleAbcissae()

◆ GetNextDiscontinuity()

◆ GetNurbForm()

◆ GetNurbFormParameterFromCurveParameter()

◆ GetParameterTolerance()

◆ GetSpanVector()

◆ GrevilleAbcissa()

◆ HasBezierSpans()

◆ HasNurbForm()

◆ IncreaseDegree()

◆ Initialize()

◆ InsertKnot()

◆ IsArc()

◆ IsClamped()

◆ IsClosed()

◆ IsContinuous()

◆ IsDeformable()

◆ IsDuplicate()

◆ IsInPlane()

◆ IsLinear()

◆ IsPeriodic()

◆ IsPlanar()

◆ IsPolyline()

◆ IsRational()

◆ IsSingular()

◆ IsValid()

◆ Knot() [1/2]

◆ Knot() [2/2]

◆ KnotCount()

◆ KnotMultiplicity()

◆ MakeClampedUniformKnotVector()

◆ MakeDeformable()

◆ MakeNonRational()

◆ MakePeriodicUniformKnotVector()

◆ MakePiecewiseBezier()

◆ MakeRational()

◆ New() [1/4]

◆ New() [2/4]

◆ New() [3/4]

◆ New() [4/4]