Open CASCADE Technology 6.6.0
Public Member Functions
GCE2d_MakeParabola Class Reference

This class implements the following algorithms used to
create Parabola from Geom2d.
* Create an Parabola from two apex and the center.
Defines the parabola in the parameterization range :
]-infinite,+infinite[
The vertex of the parabola is the "Location" point of the
local coordinate system "XAxis" of the parabola.
The "XAxis" of the parabola is its axis of symmetry.
The "Xaxis" is oriented from the vertex of the parabola to the
Focus of the parabola.
The equation of the parabola in the local coordinate system is
Y**2 = (2*P) * X
P is the distance between the focus and the directrix of the
parabola called Parameter).
The focal length F = P/2 is the distance between the vertex
and the focus of the parabola.

#include <GCE2d_MakeParabola.hxx>

Inheritance diagram for GCE2d_MakeParabola:
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Public Member Functions

 GCE2d_MakeParabola (const gp_Parab2d &Prb)
 Creates a parabola from a non persistent one.

 GCE2d_MakeParabola (const gp_Ax22d &Axis, const Standard_Real Focal)
 Creates a parabola with its local coordinate system and it's focal
length "Focal".
The "Location" point of "Axis" is the vertex of the parabola
Status is "NegativeFocusLength" if Focal < 0.0

 GCE2d_MakeParabola (const gp_Ax2d &MirrorAxis, const Standard_Real Focal, const Standard_Boolean Sense)
 Creates a parabola with its "MirrorAxis" and it's focal length "Focal".
MirrorAxis is the axis of symmetry of the curve, it is the
"XAxis". The "YAxis" is parallel to the directrix of the
parabola. The "Location" point of "MirrorAxis" is the vertex of the parabola
Status is "NegativeFocusLength" if Focal < 0.0

 GCE2d_MakeParabola (const gp_Ax22d &D, const gp_Pnt2d &F)
 Creates a parabola with the local coordinate system and the focus point.
The sense of parametrization is given by Sense.

 GCE2d_MakeParabola (const gp_Ax2d &D, const gp_Pnt2d &F, const Standard_Boolean Sense=Standard_True)
 D is the directrix of the parabola and F the focus point.
The symmetry axis "XAxis" of the parabola is normal to the
directrix and pass through the focus point F, but its
"Location" point is the vertex of the parabola.
The "YAxis" of the parabola is parallel to D and its "Location"
point is the vertex of the parabola.

 GCE2d_MakeParabola (const gp_Pnt2d &S1, const gp_Pnt2d &O)
 Make a parabola with focal point S1 and
center O
The branch of the parabola returned will have <S1> as
focal point
The implicit orientation of the parabola is:

const Handle_Geom2d_Parabola & Value () const
 Returns the constructed parabola.
Exceptions StdFail_NotDone if no parabola is constructed.

const Handle_Geom2d_Parabola & Operator () const
 operator Handle_Geom2d_Parabola () const

Constructor & Destructor Documentation

GCE2d_MakeParabola::GCE2d_MakeParabola ( const gp_Parab2d Prb)
GCE2d_MakeParabola::GCE2d_MakeParabola ( const gp_Ax22d Axis,
const Standard_Real  Focal 
)
GCE2d_MakeParabola::GCE2d_MakeParabola ( const gp_Ax2d MirrorAxis,
const Standard_Real  Focal,
const Standard_Boolean  Sense 
)
GCE2d_MakeParabola::GCE2d_MakeParabola ( const gp_Ax22d D,
const gp_Pnt2d F 
)
GCE2d_MakeParabola::GCE2d_MakeParabola ( const gp_Ax2d D,
const gp_Pnt2d F,
const Standard_Boolean  Sense = Standard_True 
)
GCE2d_MakeParabola::GCE2d_MakeParabola ( const gp_Pnt2d S1,
const gp_Pnt2d O 
)
  • the same one as the parabola Prb,
  • the sense defined by the coordinate system Axis or the directrix D,
  • the trigonometric sense if Sense is not given or is true, or
  • the opposite sense if Sense is false.
    Warning
    The MakeParabola class does not prevent the
    construction of a parabola with a null focal distance.
    If an error occurs (that is, when IsDone returns
    false), the Status function returns:
  • gce_NullFocusLength if Focal is less than 0.0, or
  • gce_NullAxis if points S1 and O are coincident.

Member Function Documentation

const Handle_Geom2d_Parabola& GCE2d_MakeParabola::Operator ( ) const
GCE2d_MakeParabola::operator Handle_Geom2d_Parabola ( ) const
const Handle_Geom2d_Parabola& GCE2d_MakeParabola::Value ( ) const

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