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Public Member Functions | Protected Attributes
Geom_Conic Class Referenceabstract

The abstract class Conic describes the common
behavior of conic curves in 3D space and, in
particular, their general characteristics. The Geom
package provides four concrete classes of conics:
Geom_Circle, Geom_Ellipse, Geom_Hyperbola and Geom_Parabola.
A conic is positioned in space with a right-handed
coordinate system (gp_Ax2 object), where:
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#include <Geom_Conic.hxx>

Inheritance diagram for Geom_Conic:
Inheritance graph
[legend]

Public Member Functions

void SetAxis (const gp_Ax1 &A1)
 
Changes the orientation of the conic's plane. The normal <br>

axis to the plane is A1. The XAxis and the YAxis are recomputed.
raised if the A1 is parallel to the XAxis of the conic.
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void SetLocation (const gp_Pnt &P)
 changes the location point of the conic.
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void SetPosition (const gp_Ax2 &A2)
 changes the local coordinate system of the conic.
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gp_Ax1 Axis () const
 
 Returns the "main Axis" of this conic. This axis is <br>

normal to the plane of the conic.
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virtual Standard_Real Eccentricity () const =0
 
Returns the eccentricity value of the conic e. <br>

e = 0 for a circle
0 < e < 1 for an ellipse (e = 0 if MajorRadius = MinorRadius)
e > 1 for a hyperbola
e = 1 for a parabola
Exceptions
Standard_DomainError in the case of a hyperbola if
its major radius is null.
More...

 
gp_Pnt Location () const
 Returns the location point of the conic.
For the circle, the ellipse and the hyperbola it is the center of
the conic. For the parabola it is the Apex of the parabola.
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const gp_Ax2Position () const
 Returns the local coordinates system of the conic.
The main direction of the Axis2Placement is normal to the
plane of the conic. The X direction of the Axis2placement
is in the plane of the conic and corresponds to the origin
for the conic's parametric value u.
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gp_Ax1 XAxis () const
 Returns the XAxis of the conic.
This axis defines the origin of parametrization of the conic.
This axis is perpendicular to the Axis of the conic.
This axis and the Yaxis define the plane of the conic.
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gp_Ax1 YAxis () const
 Returns the YAxis of the conic.
The YAxis is perpendicular to the Xaxis.
This axis and the Xaxis define the plane of the conic.
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void Reverse ()
 Reverses the direction of parameterization of <me>.
The local coordinate system of the conic is modified.
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virtual Standard_Real ReversedParameter (const Standard_Real U) const =0
 
 Returns the  parameter on the  reversed  curve for <br>
     the point of parameter U on <me>. <br>


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GeomAbs_Shape Continuity () const
 The continuity of the conic is Cn.
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Standard_Boolean IsCN (const Standard_Integer N) const
 Returns True.
//! Raised if N < 0.
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- Public Member Functions inherited from Geom_Curve
virtual Standard_Real TransformedParameter (const Standard_Real U, const gp_Trsf &T) const
 
 Returns the  parameter on the  transformed  curve for <br>
     the transform of the point of parameter U on <me>. <br>


me->Transformed(T)->Value(me->TransformedParameter(U,T))

is the same point as

me->Value(U).Transformed(T)

This methods returns <U>

It can be redefined. For example on the Line.
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virtual Standard_Real ParametricTransformation (const gp_Trsf &T) const
 
 Returns a  coefficient to compute the parameter on <br>
     the transformed  curve  for  the transform  of the <br>
     point on <me>. <br>


Transformed(T)->Value(U * ParametricTransformation(T))

is the same point as

Value(U).Transformed(T)

This methods returns 1.

It can be redefined. For example on the Line.
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Handle_Geom_Curve Reversed () const
 Returns a copy of <me> reversed.
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virtual Standard_Real FirstParameter () const =0
 
Returns the value of the first parameter. <br>

Warnings :
It can be RealFirst from package Standard
if the curve is infinite
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virtual Standard_Real LastParameter () const =0
 
 Returns the value of the last parameter. <br>

Warnings :
It can be RealLast from package Standard
if the curve is infinite
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virtual Standard_Boolean IsClosed () const =0
 
Returns true if the curve is closed. <br>

Some curves such as circle are always closed, others such as line
are never closed (by definition).
Some Curves such as OffsetCurve can be closed or not. These curves
are considered as closed if the distance between the first point
and the last point of the curve is lower or equal to the Resolution
from package gp wich is a fixed criterion independant of the
application.
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virtual Standard_Boolean IsPeriodic () const =0
 
Is the parametrization of the curve periodic ? <br>

It is possible only if the curve is closed and if the
following relation is satisfied :
for each parametric value U the distance between the point
P(u) and the point P (u + T) is lower or equal to Resolution
from package gp, T is the period and must be a constant.
There are three possibilities :
. the curve is never periodic by definition (SegmentLine)
. the curve is always periodic by definition (Circle)
. the curve can be defined as periodic (BSpline). In this case
a function SetPeriodic allows you to give the shape of the
curve. The general rule for this case is : if a curve can be
periodic or not the default periodicity set is non periodic
and you have to turn (explicitly) the curve into a periodic
curve if you want the curve to be periodic.
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virtual Standard_Real Period () const
 
 Returns the period of this curve. <br>

Exceptions Standard_NoSuchObject if this curve is not periodic.
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virtual void D0 (const Standard_Real U, gp_Pnt &P) const =0
 
Returns in P the point of parameter U. <br>

If the curve is periodic then the returned point is P(U) with
U = Ustart + (U - Uend) where Ustart and Uend are the
parametric bounds of the curve.
Raised only for the "OffsetCurve" if it is not possible to
compute the current point. For example when the first
derivative on the basis curve and the offset direction
are parallel.
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virtual void D1 (const Standard_Real U, gp_Pnt &P, gp_Vec &V1) const =0
 Returns the point P of parameter U and the first derivative V1.
//! Raised if the continuity of the curve is not C1.
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virtual void D2 (const Standard_Real U, gp_Pnt &P, gp_Vec &V1, gp_Vec &V2) const =0
 Returns the point P of parameter U, the first and second
derivatives V1 and V2.
//! Raised if the continuity of the curve is not C2.
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virtual void D3 (const Standard_Real U, gp_Pnt &P, gp_Vec &V1, gp_Vec &V2, gp_Vec &V3) const =0
 Returns the point P of parameter U, the first, the second
and the third derivative.
//! Raised if the continuity of the curve is not C3.
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virtual gp_Vec DN (const Standard_Real U, const Standard_Integer N) const =0
 The returned vector gives the value of the derivative for the
order of derivation N.
//! Raised if the continuity of the curve is not CN.

//! Raised if the derivative cannot be computed
easily. e.g. rational bspline and n > 3.
//! Raised if N < 1.
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gp_Pnt Value (const Standard_Real U) const
 
Computes the point of parameter U on <me>. <br>

If the curve is periodic then the returned point is P(U) with
U = Ustart + (U - Uend) where Ustart and Uend are the
parametric bounds of the curve.
it is implemented with D0.
Raised only for the "OffsetCurve" if it is not possible to
compute the current point. For example when the first
derivative on the basis curve and the offset direction are parallel.
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- Public Member Functions inherited from Geom_Geometry
void Mirror (const gp_Pnt &P)
 Performs the symmetrical transformation of a Geometry
with respect to the point P which is the center of the
symmetry.
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void Mirror (const gp_Ax1 &A1)
 Performs the symmetrical transformation of a Geometry
with respect to an axis placement which is the axis of the
symmetry.
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void Mirror (const gp_Ax2 &A2)
 Performs the symmetrical transformation of a Geometry
with respect to a plane. The axis placement A2 locates
the plane of the symmetry : (Location, XDirection, YDirection).
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void Rotate (const gp_Ax1 &A1, const Standard_Real Ang)
 Rotates a Geometry. A1 is the axis of the rotation.
Ang is the angular value of the rotation in radians.
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void Scale (const gp_Pnt &P, const Standard_Real S)
 Scales a Geometry. S is the scaling value.
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void Translate (const gp_Vec &V)
 Translates a Geometry. V is the vector of the tanslation.
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void Translate (const gp_Pnt &P1, const gp_Pnt &P2)
 Translates a Geometry from the point P1 to the point P2.
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virtual void Transform (const gp_Trsf &T)=0
 Transformation of a geometric object. This tansformation
can be a translation, a rotation, a symmetry, a scaling
or a complex transformation obtained by combination of
the previous elementaries transformations.
(see class Transformation of the package Geom).
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Handle_Geom_Geometry Mirrored (const gp_Pnt &P) const
 
Handle_Geom_Geometry Mirrored (const gp_Ax1 &A1) const
 
Handle_Geom_Geometry Mirrored (const gp_Ax2 &A2) const
 
Handle_Geom_Geometry Rotated (const gp_Ax1 &A1, const Standard_Real Ang) const
 
Handle_Geom_Geometry Scaled (const gp_Pnt &P, const Standard_Real S) const
 
Handle_Geom_Geometry Transformed (const gp_Trsf &T) const
 
Handle_Geom_Geometry Translated (const gp_Vec &V) const
 
Handle_Geom_Geometry Translated (const gp_Pnt &P1, const gp_Pnt &P2) const
 
virtual Handle_Geom_Geometry Copy () const =0
 Creates a new object which is a copy of this geometric object.
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- Public Member Functions inherited from MMgt_TShared
virtual void Delete () const
 Memory deallocator for transient classes. More...
 
- Public Member Functions inherited from Standard_Transient
 Standard_Transient ()
 Empty constructor. More...
 
 Standard_Transient (const Standard_Transient &)
 Copy constructor – does nothing. More...
 
Standard_Transientoperator= (const Standard_Transient &)
 Assignment operator, needed to avoid copying reference counter. More...
 
virtual ~Standard_Transient ()
 Destructor must be virtual. More...
 
virtual void ShallowDump (Standard_OStream &) const
 
virtual const
Handle_Standard_Type & 
DynamicType () const
 Returns a type information object about this object. More...
 
Standard_Boolean IsInstance (const Handle_Standard_Type &theType) const
 Returns a true value if this is an instance of Type. More...
 
Standard_Boolean IsInstance (const Standard_CString theTypeName) const
 Returns a true value if this is an instance of TypeName. More...
 
Standard_Boolean IsKind (const 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. More...
 
Standard_Boolean IsKind (const Standard_CString 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. More...
 
virtual Handle_Standard_Transient This () const
 Returns a Handle which references this object. Must never be called to objects created in stack. More...
 
Standard_Integer GetRefCount () const
 Get the reference counter of this object. More...
 

Protected Attributes

gp_Ax2 pos
 

Detailed Description

The abstract class Conic describes the common
behavior of conic curves in 3D space and, in
particular, their general characteristics. The Geom
package provides four concrete classes of conics:
Geom_Circle, Geom_Ellipse, Geom_Hyperbola and Geom_Parabola.
A conic is positioned in space with a right-handed
coordinate system (gp_Ax2 object), where:

Member Function Documentation

gp_Ax1 Geom_Conic::Axis ( ) const

 Returns the "main Axis" of this conic. This axis is <br>

normal to the plane of the conic.

GeomAbs_Shape Geom_Conic::Continuity ( ) const
virtual

The continuity of the conic is Cn.

Implements Geom_Curve.

virtual Standard_Real Geom_Conic::Eccentricity ( ) const
pure virtual

Returns the eccentricity value of the conic e. <br>

e = 0 for a circle
0 < e < 1 for an ellipse (e = 0 if MajorRadius = MinorRadius)
e > 1 for a hyperbola
e = 1 for a parabola
Exceptions
Standard_DomainError in the case of a hyperbola if
its major radius is null.

Implemented in Geom_Hyperbola, Geom_Ellipse, Geom_Parabola, and Geom_Circle.

Standard_Boolean Geom_Conic::IsCN ( const Standard_Integer  N) const
virtual

Returns True.
//! Raised if N < 0.

Implements Geom_Curve.

gp_Pnt Geom_Conic::Location ( ) const

Returns the location point of the conic.
For the circle, the ellipse and the hyperbola it is the center of
the conic. For the parabola it is the Apex of the parabola.

const gp_Ax2& Geom_Conic::Position ( ) const

Returns the local coordinates system of the conic.
The main direction of the Axis2Placement is normal to the
plane of the conic. The X direction of the Axis2placement
is in the plane of the conic and corresponds to the origin
for the conic's parametric value u.

void Geom_Conic::Reverse ( )
virtual

Reverses the direction of parameterization of <me>.
The local coordinate system of the conic is modified.

Implements Geom_Curve.

virtual Standard_Real Geom_Conic::ReversedParameter ( const Standard_Real  U) const
pure virtual

 Returns the  parameter on the  reversed  curve for <br>
     the point of parameter U on <me>. <br>


Implements Geom_Curve.

Implemented in Geom_Hyperbola, Geom_Ellipse, Geom_Parabola, and Geom_Circle.

void Geom_Conic::SetAxis ( const gp_Ax1 A1)

Changes the orientation of the conic's plane. The normal <br>

axis to the plane is A1. The XAxis and the YAxis are recomputed.
raised if the A1 is parallel to the XAxis of the conic.

void Geom_Conic::SetLocation ( const gp_Pnt P)

changes the location point of the conic.

void Geom_Conic::SetPosition ( const gp_Ax2 A2)

changes the local coordinate system of the conic.

gp_Ax1 Geom_Conic::XAxis ( ) const

Returns the XAxis of the conic.
This axis defines the origin of parametrization of the conic.
This axis is perpendicular to the Axis of the conic.
This axis and the Yaxis define the plane of the conic.

gp_Ax1 Geom_Conic::YAxis ( ) const

Returns the YAxis of the conic.
The YAxis is perpendicular to the Xaxis.
This axis and the Xaxis define the plane of the conic.

Field Documentation

gp_Ax2 Geom_Conic::pos
protected

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