ON_Circle Class Reference

ON_Circle is a circle in 3d. The cirle is represented by a radius and an orthonormal frame of the plane containing the circle, with origin at the center. More...

#include <opennurbs_circle.h>

Inheritance diagram for ON_Circle:

Public Member Functions
	ON_Circle ()=default
	ON_Circle (const ON_Circle &)=default
	ON_Circle (const ON_Plane &plane, double radius)
	ON_Circle (const ON_3dPoint &center, double radius)
	ON_Circle (const ON_Plane &plane, const ON_3dPoint &center, double radius)
	ON_Circle (const ON_2dPoint &P, const ON_2dPoint &Q, const ON_2dPoint &R)
	ON_Circle (const ON_3dPoint &P, const ON_3dPoint &Q, const ON_3dPoint &R)
	~ON_Circle ()=default
ON_BoundingBox	BoundingBox () const
const ON_3dPoint &	Center () const
double	Circumference () const
bool	ClosestPointTo (const ON_3dPoint &point, double *t) const
	returns parameters of point on circle that is closest to given point More...
ON_3dPoint	ClosestPointTo (const ON_3dPoint &point) const
	returns point on circle that is closest to given point More...
bool	Create (const ON_Plane &plane, double radius)
bool	Create (const ON_3dPoint &center, double radius)
bool	Create (const ON_Plane &plane, const ON_3dPoint &center, double radius)
bool	Create (const ON_2dPoint &P, const ON_2dPoint &Q, const ON_2dPoint &R)
bool	Create (const ON_3dPoint &P, const ON_3dPoint &Q, const ON_3dPoint &R)
bool	Create (const ON_2dPoint &P, const ON_2dVector &tangent_at_P, const ON_2dPoint &Q)
bool	Create (const ON_3dPoint &P, const ON_3dVector &tangent_at_P, const ON_3dPoint &Q)
ON_3dVector	DerivativeAt (int, double) const
double	Diameter () const
double	EquationAt (const ON_2dPoint &plane_point) const
	evaluate circle's implicit equation in plane More...
int	GetNurbForm (ON_NurbsCurve &nurbs_curve) const
	Get a four span rational degree 2 NURBS circle representation of the circle. More...
bool	GetNurbFormParameterFromRadian (double circle_radians_parameter, double *nurbs_parameter) const
	Convert a circle radians parameter to a NURBS curve circle parameter. More...
bool	GetRadianFromNurbFormParameter (double nurbs_parameter, double *circle_radians_parameter) const
	Convert a NURBS curve circle parameter to a circle radians parameter. More...
bool	GetTightBoundingBox (ON_BoundingBox &tight_bbox, bool bGrowBox=false, const ON_Xform *xform=nullptr) const
	Get tight bounding box. More...
ON_2dVector	GradientAt (const ON_2dPoint &plane_point) const
bool	IsInPlane (const ON_Plane &, double=ON_ZERO_TOLERANCE) const
	bool UpdatePoints(); // sets m_point[] to have valid points More...
bool	IsValid () const
	A Valid circle has m_radius>0 and m_plane.IsValid(). More...
const ON_3dVector &	Normal () const
ON_Circle &	operator= (const ON_Circle &)=default
const ON_Plane &	Plane () const
ON_3dPoint	PointAt (double) const
double	Radius () const
bool	Reverse ()
bool	Rotate (double sin_angle, double cos_angle, const ON_3dVector &axis_of_rotation)
	rotate circle about its center More...
bool	Rotate (double angle_in_radians, const ON_3dVector &axis_of_rotation)
bool	Rotate (double sin_angle, double cos_angle, const ON_3dVector &axis_of_rotation, const ON_3dPoint &center_of_rotation)
	rotate circle about a point and axis More...
bool	Rotate (double angle_in_radians, const ON_3dVector &axis_of_rotation, const ON_3dPoint &center_of_rotation)
ON_3dVector	TangentAt (double) const
bool	Transform (const ON_Xform &)
bool	Translate (const ON_3dVector &delta)

Public Attributes
ON_Plane	plane = ON_Plane::World_xy
double	radius = 1.0

Static Public Attributes
static const ON_Circle	UnitCircle

Detailed Description

ON_Circle is a circle in 3d. The cirle is represented by a radius and an orthonormal frame of the plane containing the circle, with origin at the center.

An Is_Valid() circle has positive radius and an Is_ Valid() plane defining the frame.

The circle is parameterized by radians from 0 to 2 Pi given by t -> center + cos(t)*radius*xaxis + sin(t)*radius*yaxis where center, xaxis and yaxis define the orthonormal frame of the circle's plane.

Constructor & Destructor Documentation

ON_Circle() [1/7]

ON_Circle::ON_Circle ( )

default

~ON_Circle()

ON_Circle::~ON_Circle ( )

default

ON_Circle() [2/7]

ON_Circle::ON_Circle ( const ON_Circle &  )

default

ON_Circle() [3/7]

ON_Circle::ON_Circle	(	const ON_Plane &	plane,
		double	radius
	)

ON_Circle() [4/7]

ON_Circle::ON_Circle	(	const ON_3dPoint &	center,
		double	radius
	)

ON_Circle() [5/7]

ON_Circle::ON_Circle	(	const ON_Plane &	plane,
		const ON_3dPoint &	center,
		double	radius
	)

ON_Circle() [6/7]

ON_Circle::ON_Circle	(	const ON_2dPoint &	P,
		const ON_2dPoint &	Q,
		const ON_2dPoint &	R
	)

ON_Circle() [7/7]

ON_Circle::ON_Circle	(	const ON_3dPoint &	P,
		const ON_3dPoint &	Q,
		const ON_3dPoint &	R
	)

Member Function Documentation

BoundingBox()

ON_BoundingBox ON_Circle::BoundingBox

(

)

const

Center()

const ON_3dPoint& ON_Circle::Center

(

)

const

Circumference()

double ON_Circle::Circumference

(

)

const

ClosestPointTo() [1/2]

bool ON_Circle::ClosestPointTo	(	const ON_3dPoint &	point,
		double *	t
	)		const

returns parameters of point on circle that is closest to given point

ClosestPointTo() [2/2]

ON_3dPoint ON_Circle::ClosestPointTo

(

const ON_3dPoint &

point

)

const

returns point on circle that is closest to given point

Create() [1/7]

bool ON_Circle::Create	(	const ON_Plane &	plane,
		double	radius
	)

Create() [2/7]

bool ON_Circle::Create	(	const ON_3dPoint &	center,
		double	radius
	)

Create() [3/7]

bool ON_Circle::Create	(	const ON_Plane &	plane,
		const ON_3dPoint &	center,
		double	radius
	)

Create() [4/7]

bool ON_Circle::Create	(	const ON_2dPoint &	P,
		const ON_2dPoint &	Q,
		const ON_2dPoint &	R
	)

Create() [5/7]

bool ON_Circle::Create	(	const ON_3dPoint &	P,
		const ON_3dPoint &	Q,
		const ON_3dPoint &	R
	)

Create() [6/7]

bool ON_Circle::Create	(	const ON_2dPoint &	P,
		const ON_2dVector &	tangent_at_P,
		const ON_2dPoint &	Q
	)

Create() [7/7]

bool ON_Circle::Create	(	const ON_3dPoint &	P,
		const ON_3dVector &	tangent_at_P,
		const ON_3dPoint &	Q
	)

DerivativeAt()

ON_3dVector ON_Circle::DerivativeAt	(	int	,
		double
	)		const

Diameter()

double ON_Circle::Diameter

(

)

const

EquationAt()

double ON_Circle::EquationAt

(

const ON_2dPoint &

plane_point

)

const

evaluate circle's implicit equation in plane

GetNurbForm()

int ON_Circle::GetNurbForm

(

ON_NurbsCurve &

nurbs_curve

)

const

Get a four span rational degree 2 NURBS circle representation of the circle.

Returns

2 for success, 0 for failure

Note that the parameterization of NURBS curve does not match circle's transcendental paramaterization. Use ON_Circle::GetRadianFromNurbFormParameter() and ON_Circle::GetParameterFromRadian() to convert between the NURBS curve parameter and the transcendental parameter.

GetNurbFormParameterFromRadian()

bool ON_Circle::GetNurbFormParameterFromRadian	(	double	circle_radians_parameter,
		double *	nurbs_parameter
	)		const

Convert a circle radians parameter to a NURBS curve circle parameter.

Parameters

circle_radians_parameter	[in] 0.0 to 2.0*ON_PI
nurbs_parameter	[out]

The NURBS curve parameter is with respect to the NURBS curve created by ON_Circle::GetNurbForm. At radian values of 0.0, 0.5*ON_PI, ON_PI, 1.5*ON_PI, and 2.0*ON_PI, the nurbs parameter and radian parameter are the same. At all other values the nurbs and radian parameter values are different.

@verbatim
    ON_Circle circle = ...;
    double circle_t = 1.2345; // some number in interval (0,2.0*ON_PI).
    double nurbs_t;
    circle.GetNurbFormParameterFromRadian( circle_t, &nurbs_t );

    ON_NurbsCurve nurbs_curve;
    circle.GetNurbsForm( nurbs_curve );
    circle_pt = circle.PointAt(circle_t);
    nurbs_pt = nurbs_curve.PointAt(nurbs_t);
    // circle_pt and nurbs_pt will be the same
@endverbatim

See also

ON_Circle::GetNurbFormParameterFromRadian

GetRadianFromNurbFormParameter()

bool ON_Circle::GetRadianFromNurbFormParameter	(	double	nurbs_parameter,
		double *	circle_radians_parameter
	)		const

Convert a NURBS curve circle parameter to a circle radians parameter.

Parameters

nurbs_parameter	[in]
circle_radians_parameter	[out]

The NURBS curve parameter is with respect to the NURBS curve created by ON_Circle::GetNurbForm. At nurbs parameter values of 0.0, 0.5*ON_PI, ON_PI, 1.5*ON_PI, and 2.0*ON_PI, the nurbs parameter and radian parameter are the same. At all other values the nurbs and radian parameter values are different.

@verbatim
    ON_Circle circle = ...;
    double nurbs_t = 1.2345; // some number in interval (0,2.0*ON_PI).
    double circle_t;
    circle.GetRadianFromNurbFormParameter( nurbs_t, &circle_t );

    ON_NurbsCurve nurbs_curve;
    circle.GetNurbsForm( nurbs_curve );
    circle_pt = circle.PointAt(circle_t);
    nurbs_pt = nurbs_curve.PointAt(nurbs_t);
    // circle_pt and nurbs_pt will be the same
@endverbatim

See also

ON_Circle::GetNurbFormParameterFromRadian

GetTightBoundingBox()

bool ON_Circle::GetTightBoundingBox	(	ON_BoundingBox &	tight_bbox,
		bool	bGrowBox = false,
		const ON_Xform *	xform = nullptr
	)		const

Get tight bounding box.

Parameters

tight_bbox	[in/out] tight bounding box
bGrowBox	[in] (default=false) If true and the input tight_bbox is valid, then returned tight_bbox is the union of the input tight_bbox and the arc's tight bounding box.
xform	[in] (default=nullptr) If not nullptr, the tight bounding box of the transformed arc is calculated. The arc is not modified.

Returns

True if a valid tight_bbox is returned.

GradientAt()

ON_2dVector ON_Circle::GradientAt

(

const ON_2dPoint &

plane_point

)

const

IsInPlane()

bool ON_Circle::IsInPlane	(	const ON_Plane &	,
		double	= ON_ZERO_TOLERANCE
	)		const

bool UpdatePoints(); // sets m_point[] to have valid points

IsValid()

bool ON_Circle::IsValid

(

)

const

A Valid circle has m_radius>0 and m_plane.IsValid().

Normal()

const ON_3dVector& ON_Circle::Normal

(

)

const

operator=()

ON_Circle& ON_Circle::operator= ( const ON_Circle &  )

default

Plane()

const ON_Plane& ON_Circle::Plane

(

)

const

PointAt()

ON_3dPoint ON_Circle::PointAt

(

double

)

const

Radius()

double ON_Circle::Radius

(

)

const

Reverse()

bool ON_Circle::Reverse

(

)

Rotate() [1/4]

bool ON_Circle::Rotate	(	double	sin_angle,
		double	cos_angle,
		const ON_3dVector &	axis_of_rotation
	)

rotate circle about its center

Rotate() [2/4]

bool ON_Circle::Rotate	(	double	angle_in_radians,
		const ON_3dVector &	axis_of_rotation
	)

Rotate() [3/4]

bool ON_Circle::Rotate	(	double	sin_angle,
		double	cos_angle,
		const ON_3dVector &	axis_of_rotation,
		const ON_3dPoint &	center_of_rotation
	)

rotate circle about a point and axis

Rotate() [4/4]

bool ON_Circle::Rotate	(	double	angle_in_radians,
		const ON_3dVector &	axis_of_rotation,
		const ON_3dPoint &	center_of_rotation
	)

TangentAt()

ON_3dVector ON_Circle::TangentAt

(

double

)

const

Transform()

bool ON_Circle::Transform

(

const ON_Xform &

)

Translate()

bool ON_Circle::Translate

(

const ON_3dVector &

delta

)

Member Data Documentation

plane

ON_Plane ON_Circle::plane = ON_Plane::World_xy

radius

double ON_Circle::radius = 1.0

UnitCircle

const ON_Circle ON_Circle::UnitCircle

static