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TKG3d
Geom


Geom_Circle Class Reference

Describes a circle in 3D space.
A circle is defined by its radius and, as with any conic
curve, is positioned in space with a right-handed
coordinate system (gp_Ax2 object) where:
- the origin is the center of the circle, and
- the origin, "X Direction" and "Y Direction" define the
plane of the circle.
This coordinate system is the local coordinate
system of the circle.
The "main Direction" of this coordinate system is the
vector normal to the plane of the circle. The axis, of
which the origin and unit vector are respectively the
origin and "main Direction" of the local coordinate
system, is termed the "Axis" or "main Axis" of the circle.
The "main Direction" of the local coordinate system
gives an explicit orientation to the circle (definition of
the trigonometric sense), determining the direction in
which the parameter increases along the circle.
The Geom_Circle circle is parameterized by an angle:
P(U) = O + R*Cos(U)*XDir + R*Sin(U)*YDir, where:
- P is the point of parameter U,
- O, XDir and YDir are respectively the origin, "X <br> Direction" and "Y Direction" of its local coordinate system,
- R is the radius of the circle.
The "X Axis" of the local coordinate system therefore
defines the origin of the parameter of the circle. The
parameter is the angle with this "X Direction".
A circle is a closed and periodic curve. The period is
2.*Pi and the parameter range is [ 0, 2.*Pi [.
.

#include <Geom_Circle.hxx>

Inheritance diagram for Geom_Circle:

Inheritance graph
[legend]

Public Member Functions

Standard_EXPORT Geom_Circle (const gp_Circ &C)
 Constructs a circle by conversion of the gp_Circ circle C.
.
Standard_EXPORT Geom_Circle (const gp_Ax2 &A2, const Standard_Real Radius)
 Constructs a circle of radius Radius, where A2 locates the circle and
defines its orientation in 3D space such that:
- the center of the circle is the origin of A2,
- the origin, "X Direction" and "Y Direction" of A2
define the plane of the circle,
- A2 is the local coordinate system of the circle.
Note: It is possible to create a circle where Radius is equal to 0.0.
//! raised if Radius < 0.
.
Standard_EXPORT void SetCirc (const gp_Circ &C)
 Set <me> so that <me> has the same geometric properties as C.
.
Standard_EXPORT void SetRadius (const Standard_Real R)
 Assigns the value R to the radius of this circle.
Note: it is possible to have a circle with a radius equal to 0.0.
Exceptions - Standard_ConstructionError if R is negative.
.
Standard_EXPORT gp_Circ Circ () const
 returns the non transient circle from gp with the same
geometric properties as <me>.

Standard_EXPORT Standard_Real Radius () const
 Returns the radius of this circle.
.
Standard_EXPORT Standard_Real ReversedParameter (const Standard_Real U) const
 Computes the parameter on the reversed circle for
the point of parameter U on this circle.
For a circle, the returned value is: 2.*Pi - U.
.
Standard_EXPORT Standard_Real Eccentricity () const
 Returns the eccentricity e = 0 for a circle.
.
Standard_EXPORT Standard_Real FirstParameter () const
 Returns the value of the first parameter of this
circle. This is 0.0, which gives the start point of this circle, or
The start point and end point of a circle are coincident.
.
Standard_EXPORT Standard_Real LastParameter () const
 Returns the value of the last parameter of this
circle. This is 2.*Pi, which gives the end point of this circle.
The start point and end point of a circle are coincident.
.
Standard_EXPORT Standard_Boolean IsClosed () const
 returns True.

Standard_EXPORT Standard_Boolean IsPeriodic () const
 returns True.

Standard_EXPORT void D0 (const Standard_Real U, gp_Pnt &P) const
 Returns in P the point of parameter U.
P = C + R * Cos (U) * XDir + R * Sin (U) * YDir
where C is the center of the circle , XDir the XDirection and
YDir the YDirection of the circle's local coordinate system.
.
Standard_EXPORT void D1 (const Standard_Real U, gp_Pnt &P, gp_Vec &V1) const
 Returns the point P of parameter U and the first derivative V1.
.
Standard_EXPORT void D2 (const Standard_Real U, gp_Pnt &P, gp_Vec &V1, gp_Vec &V2) const
 Returns the point P of parameter U, the first and second
derivatives V1 and V2.
.
Standard_EXPORT void D3 (const Standard_Real U, gp_Pnt &P, gp_Vec &V1, gp_Vec &V2, gp_Vec &V3) const
 Returns the point P of parameter u, the first second and third
derivatives V1 V2 and V3.
.
Standard_EXPORT gp_Vec DN (const Standard_Real U, const Standard_Integer N) const
 The returned vector gives the value of the derivative for the
order of derivation N.
//! Raised if N < 1.
.
Standard_EXPORT void Transform (const gp_Trsf &T)
 Applies the transformation T to this circle.
.
Standard_EXPORT Handle_Geom_Geometry Copy () const
 Creates a new object which is a copy of this circle.
.
Standard_EXPORT const Handle (Standard_Type)&DynamicType() const

Private Attributes

Standard_Real radius

Constructor & Destructor Documentation

Standard_EXPORT Geom_Circle::Geom_Circle const gp_Circ &  C  ) 
 

Standard_EXPORT Geom_Circle::Geom_Circle const gp_Ax2 &  A2,
const Standard_Real  Radius
 


Member Function Documentation

Standard_EXPORT gp_Circ Geom_Circle::Circ  )  const
 

Standard_EXPORT Handle_Geom_Geometry Geom_Circle::Copy  )  const [virtual]
 

Implements Geom_Geometry.

Standard_EXPORT void Geom_Circle::D0 const Standard_Real  U,
gp_Pnt &  P
const [virtual]
 

Implements Geom_Curve.

Standard_EXPORT void Geom_Circle::D1 const Standard_Real  U,
gp_Pnt &  P,
gp_Vec &  V1
const [virtual]
 

Implements Geom_Curve.

Standard_EXPORT void Geom_Circle::D2 const Standard_Real  U,
gp_Pnt &  P,
gp_Vec &  V1,
gp_Vec &  V2
const [virtual]
 

Implements Geom_Curve.

Standard_EXPORT void Geom_Circle::D3 const Standard_Real  U,
gp_Pnt &  P,
gp_Vec &  V1,
gp_Vec &  V2,
gp_Vec &  V3
const [virtual]
 

Implements Geom_Curve.

Standard_EXPORT gp_Vec Geom_Circle::DN const Standard_Real  U,
const Standard_Integer  N
const [virtual]
 

Implements Geom_Curve.

Standard_EXPORT Standard_Real Geom_Circle::Eccentricity  )  const [virtual]
 

Implements Geom_Conic.

Standard_EXPORT Standard_Real Geom_Circle::FirstParameter  )  const [virtual]
 

Implements Geom_Curve.

Standard_EXPORT const Geom_Circle::Handle Standard_Type   )  const
 

Reimplemented from Geom_Conic.

Standard_EXPORT Standard_Boolean Geom_Circle::IsClosed  )  const [virtual]
 

Implements Geom_Curve.

Standard_EXPORT Standard_Boolean Geom_Circle::IsPeriodic  )  const [virtual]
 

Implements Geom_Curve.

Standard_EXPORT Standard_Real Geom_Circle::LastParameter  )  const [virtual]
 

Implements Geom_Curve.

Standard_EXPORT Standard_Real Geom_Circle::Radius  )  const
 

Standard_EXPORT Standard_Real Geom_Circle::ReversedParameter const Standard_Real  U  )  const [virtual]
 

Implements Geom_Conic.

Standard_EXPORT void Geom_Circle::SetCirc const gp_Circ &  C  ) 
 

Standard_EXPORT void Geom_Circle::SetRadius const Standard_Real  R  ) 
 

Standard_EXPORT void Geom_Circle::Transform const gp_Trsf &  T  )  [virtual]
 

Implements Geom_Geometry.


Field Documentation

Standard_Real Geom_Circle::radius [private]
 


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