# FoundationClasses
TKMath
gp

# gp_Parab2d Class Reference

Describes a parabola in the plane (2D space).
A parabola is defined by its focal length (that is, the
distance between its focus and apex) and positioned in
the plane with a coordinate system (a gp_Ax22d object) where:
- the origin of the coordinate system is on the apex of
the parabola, and
- the "X Axis" of the coordinate system is the axis of
symmetry; the parabola is on the positive side of this axis.
This coordinate system is the "local coordinate system"
of the parabola. Its orientation (direct or indirect sense)
gives an implicit orientation to the parabola.
In this coordinate system, the equation for the parabola is:
Y**2 = (2*P) * X.
where P, referred to as the parameter of the parabola, is
the distance between the focus and the directrix (P is
twice the focal length).
See Also
GCE2d_MakeParab2d which provides functions for
more complex parabola constructions
Geom2d_Parabola which provides additional functions
for constructing parabolas and works, in particular, with
the parametric equations of parabolas
.

`#include <gp_Parab2d.hxx>`

## Public Member Functions

void * | operator new (size_t, void *anAddress)
void * | operator new (size_t size)
void | operator delete (void *anAddress)
| gp_Parab2d ()
| Creates an indefinite parabola. .
| gp_Parab2d (const gp_Ax2d &MirrorAxis, const Standard_Real Focal, const Standard_Boolean Sense=Standard_True)
| Creates a parabola with its vertex point, its axis of symmetry ("XAxis") and its focal length. The sense of parametrization is given by Sense. Warnings : It is possible to have Focal = 0. Raises ConstructionError if Focal < 0.0 .
| gp_Parab2d (const gp_Ax22d &A, const Standard_Real Focal)
| Creates a parabola with its vertex point, its axis of symmetry ("XAxis") and its focal length. The sense of parametrization is given by A. Warnings : It is possible to have Focal = 0. Raises ConstructionError if Focal < 0.0 .
Standard_EXPORT | gp_Parab2d (const gp_Ax2d &D, const gp_Pnt2d &F, const Standard_Boolean Sense=Standard_True)
| Creates a parabola with the directrix and the focus point. The sense of parametrization is given by Sense. .
Standard_EXPORT | gp_Parab2d (const gp_Ax22d &D, const gp_Pnt2d &F)
| Creates a parabola with the directrix and the focus point. The Sense of parametrization is given by D. .
void | SetFocal (const Standard_Real Focal)
| Changes the focal distance of the parabola Warnings : It is possible to have Focal = 0. Raises ConstructionError if Focal < 0.0 .
void | SetLocation (const gp_Pnt2d &P)
| Changes the "Location" point of the parabola. It is the vertex of the parabola. .
void | SetMirrorAxis (const gp_Ax2d &A)
| Modifies this parabola, by redefining its local coordinate system so that its origin and "X Direction" become those of the axis MA. The "Y Direction" of the local coordinate system is then recomputed. The orientation of the local coordinate system is not modified. .
void | SetAxis (const gp_Ax22d &A)
| Changes the local coordinate system of the parabola. The "Location" point of A becomes the vertex of the parabola. .
Standard_EXPORT void | Coefficients (Standard_Real &A, Standard_Real &B, Standard_Real &C, Standard_Real &D, Standard_Real &E, Standard_Real &F) const
| Computes the coefficients of the implicit equation of the parabola. A * (X**2) + B * (Y**2) + 2*C*(X*Y) + 2*D*X + 2*E*Y + F = 0. .
gp_Ax2d | Directrix () const

Computes the directrix of the parabola.
The directrix is:
- a line parallel to the "Y Direction" of the local
coordinate system of this parabola, and
- located on the negative side of the axis of symmetry,
at a distance from the apex which is equal to the focal length of this parabola.
The directrix is returned as an axis (a gp_Ax2d object),
the origin of which is situated on the "X Axis" of this parabola.
.

Standard_Real | Focal () const
| Returns the distance between the vertex and the focus of the parabola. .
gp_Pnt2d | Focus () const
| Returns the focus of the parabola. .
gp_Pnt2d | Location () const
| Returns the vertex of the parabola. .
gp_Ax2d | MirrorAxis () const
| Returns the symmetry axis of the parabola. The "Location" point of this axis is the vertex of the parabola. .
gp_Ax22d | Axis () const
| Returns the local coordinate system of the parabola. The "Location" point of this axis is the vertex of the parabola. .
Standard_Real | Parameter () const
| Returns the distance between the focus and the directrix of the parabola. .
void | Reverse ()
gp_Parab2d | Reversed () const
| Reverses the orientation of the local coordinate system of this parabola (the "Y Direction" is reversed). Therefore, the implicit orientation of this parabola is reversed. Note: - Reverse assigns the result to this parabola, while - Reversed creates a new one. .
Standard_Boolean | IsDirect () const
| Returns true if the local coordinate system is direct and false in the other case. .
Standard_EXPORT void | Mirror (const gp_Pnt2d &P)
Standard_EXPORT gp_Parab2d | Mirrored (const gp_Pnt2d &P) const
| Performs the symmetrical transformation of a parabola with respect to the point P which is the center of the symmetry .
Standard_EXPORT void | Mirror (const gp_Ax2d &A)
Standard_EXPORT gp_Parab2d | Mirrored (const gp_Ax2d &A) const
| Performs the symmetrical transformation of a parabola with respect to an axis placement which is the axis of the symmetry. .
void | Rotate (const gp_Pnt2d &P, const Standard_Real Ang)
gp_Parab2d | Rotated (const gp_Pnt2d &P, const Standard_Real Ang) const
| Rotates a parabola. P is the center of the rotation. Ang is the angular value of the rotation in radians. .
void | Scale (const gp_Pnt2d &P, const Standard_Real S)
gp_Parab2d | Scaled (const gp_Pnt2d &P, const Standard_Real S) const
| Scales a parabola. S is the scaling value. If S is negative the direction of the symmetry axis "XAxis" is reversed and the direction of the "YAxis" too. .
void | Transform (const gp_Trsf2d &T)
gp_Parab2d | Transformed (const gp_Trsf2d &T) const
| Transforms an parabola with the transformation T from class Trsf2d. .
void | Translate (const gp_Vec2d &V)
gp_Parab2d | Translated (const gp_Vec2d &V) const
| Translates a parabola in the direction of the vector V. The magnitude of the translation is the vector's magnitude. .
void | Translate (const gp_Pnt2d &P1, const gp_Pnt2d &P2)
gp_Parab2d | Translated (const gp_Pnt2d &P1, const gp_Pnt2d &P2) const
| Translates a parabola from the point P1 to the point P2. .
const gp_Ax22d & | _CSFDB_Getgp_Parab2dpos () const
Standard_Real | _CSFDB_Getgp_Parab2dfocalLength () const
void | _CSFDB_Setgp_Parab2dfocalLength (const Standard_Real p)

## Private Attributes

gp_Ax22d | pos
Standard_Real | focalLength

## Friends

Standard_EXPORT friend Handle_Standard_Type & | gp_Parab2d_Type_ ()

## Constructor & Destructor Documentation

gp_Parab2d::gp_Parab2d | ( |  | ) | `[inline]`

gp_Parab2d::gp_Parab2d | ( | const gp_Ax2d & | MirrorAxis,
|  | const Standard_Real | Focal,
|  | const Standard_Boolean | Sense = `Standard_True`
| ) | `[inline]`

gp_Parab2d::gp_Parab2d | ( | const gp_Ax22d & | A,
|  | const Standard_Real | Focal
| ) | `[inline]`

Standard_EXPORT gp_Parab2d::gp_Parab2d | ( | const gp_Ax2d & | D,
|  | const gp_Pnt2d & | F,
|  | const Standard_Boolean | Sense = `Standard_True`
| ) |

Standard_EXPORT gp_Parab2d::gp_Parab2d | ( | const gp_Ax22d & | D,
|  | const gp_Pnt2d & | F
| ) |

## Member Function Documentation

Standard_Real gp_Parab2d::_CSFDB_Getgp_Parab2dfocalLength | ( |  | ) | const`[inline]`

const gp_Ax22d& gp_Parab2d::_CSFDB_Getgp_Parab2dpos | ( |  | ) | const`[inline]`

void gp_Parab2d::_CSFDB_Setgp_Parab2dfocalLength | ( | const Standard_Real | p | ) | `[inline]`

gp_Ax22d gp_Parab2d::Axis | ( |  | ) | const`[inline]`

Standard_EXPORT void gp_Parab2d::Coefficients | ( | Standard_Real & | A,
|  | Standard_Real & | B,
|  | Standard_Real & | C,
|  | Standard_Real & | D,
|  | Standard_Real & | E,
|  | Standard_Real & | F
| ) | const

gp_Ax2d gp_Parab2d::Directrix | ( |  | ) | const`[inline]`

Standard_Real gp_Parab2d::Focal | ( |  | ) | const`[inline]`

gp_Pnt2d gp_Parab2d::Focus | ( |  | ) | const`[inline]`

Standard_Boolean gp_Parab2d::IsDirect | ( |  | ) | const`[inline]`

gp_Pnt2d gp_Parab2d::Location | ( |  | ) | const`[inline]`

Standard_EXPORT void gp_Parab2d::Mirror | ( | const gp_Ax2d & | A | ) |

Standard_EXPORT void gp_Parab2d::Mirror | ( | const gp_Pnt2d & | P | ) |

gp_Ax2d gp_Parab2d::MirrorAxis | ( |  | ) | const`[inline]`

Standard_EXPORT gp_Parab2d gp_Parab2d::Mirrored | ( | const gp_Ax2d & | A | ) | const

Standard_EXPORT gp_Parab2d gp_Parab2d::Mirrored | ( | const gp_Pnt2d & | P | ) | const

void gp_Parab2d::operator delete | ( | void * | anAddress | ) | `[inline]`

void* gp_Parab2d::operator new | ( | size_t | size | ) | `[inline]`

void* gp_Parab2d::operator new | ( | size_t | ,
|  | void * | anAddress
| ) | `[inline]`

Standard_Real gp_Parab2d::Parameter | ( |  | ) | const`[inline]`

void gp_Parab2d::Reverse | ( |  | ) | `[inline]`

gp_Parab2d gp_Parab2d::Reversed | ( |  | ) | const`[inline]`

void gp_Parab2d::Rotate | ( | const gp_Pnt2d & | P,
|  | const Standard_Real | Ang
| ) | `[inline]`

gp_Parab2d gp_Parab2d::Rotated | ( | const gp_Pnt2d & | P,
|  | const Standard_Real | Ang
| ) | const`[inline]`

void gp_Parab2d::Scale | ( | const gp_Pnt2d & | P,
|  | const Standard_Real | S
| ) | `[inline]`

gp_Parab2d gp_Parab2d::Scaled | ( | const gp_Pnt2d & | P,
|  | const Standard_Real | S
| ) | const`[inline]`

void gp_Parab2d::SetAxis | ( | const gp_Ax22d & | A | ) | `[inline]`

void gp_Parab2d::SetFocal | ( | const Standard_Real | Focal | ) | `[inline]`

void gp_Parab2d::SetLocation | ( | const gp_Pnt2d & | P | ) | `[inline]`

void gp_Parab2d::SetMirrorAxis | ( | const gp_Ax2d & | A | ) | `[inline]`

void gp_Parab2d::Transform | ( | const gp_Trsf2d & | T | ) | `[inline]`

gp_Parab2d gp_Parab2d::Transformed | ( | const gp_Trsf2d & | T | ) | const`[inline]`

void gp_Parab2d::Translate | ( | const gp_Pnt2d & | P1,
|  | const gp_Pnt2d & | P2
| ) | `[inline]`

void gp_Parab2d::Translate | ( | const gp_Vec2d & | V | ) | `[inline]`

gp_Parab2d gp_Parab2d::Translated | ( | const gp_Pnt2d & | P1,
|  | const gp_Pnt2d & | P2
| ) | const`[inline]`

gp_Parab2d gp_Parab2d::Translated | ( | const gp_Vec2d & | V | ) | const`[inline]`

## Friends And Related Function Documentation

Standard_EXPORT friend Handle_Standard_Type& gp_Parab2d_Type_ | ( |  | ) | `[friend]`

## Field Documentation

Standard_Real gp_Parab2d::focalLength `[private]`

gp_Ax22d gp_Parab2d::pos `[private]`

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

- gp_Parab2d.hxx
- gp_Parab2d.lxx