# FoundationClasses
TKMath
gp

# gp_Parab Class Reference

Describes a parabola in 3D space.
A parabola is defined by its focal length (that is, the
distance between its focus and apex) and positioned in
space with a coordinate system (a gp_Ax2 object)
where:
- the origin of the coordinate system is on the apex of
the parabola,
- the "X Axis" of the coordinate system is the axis of
symmetry; the parabola is on the positive side of this axis, and
- the origin, "X Direction" and "Y Direction" of the
coordinate system define the plane of the parabola.
The equation of the parabola in this coordinate system,
which is the "local coordinate system" of 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).
The "main Direction" of the local coordinate system gives
the normal vector to the plane of the parabola.
See Also
gce_MakeParab which provides functions for more
complex parabola constructions
Geom_Parabola which provides additional functions for
constructing parabolas and works, in particular, with the
parametric equations of parabolas
.

`#include <gp_Parab.hxx>`

## Public Member Functions

void * | operator new (size_t, void *anAddress)
void * | operator new (size_t size)
void | operator delete (void *anAddress)
| gp_Parab ()
| Creates an indefinite Parabola. .
| gp_Parab (const gp_Ax2 &A2, const Standard_Real Focal)
| Creates a parabola with its local coordinate system "A2" and it's focal length "Focal". The XDirection of A2 defines the axis of symmetry of the parabola. The YDirection of A2 is parallel to the directrix of the parabola. The Location point of A2 is the vertex of the parabola Raises ConstructionError if Focal < 0.0 //! Raised if Focal < 0.0 .
| gp_Parab (const gp_Ax1 &D, const gp_Pnt &F)

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. The normal to the plane
of the parabola is the cross product between the XAxis and the
YAxis.
.

void | SetAxis (const gp_Ax1 &A1)
| Modifies this parabola by redefining its local coordinate system so that - its origin and "main Direction" become those of the axis A1 (the "X Direction" and "Y Direction" are then recomputed in the same way as for any gp_Ax2) Raises ConstructionError if the direction of A1 is parallel to the previous XAxis of the parabola. .
void | SetFocal (const Standard_Real Focal)
| Changes the focal distance of the parabola. Raises ConstructionError if Focal < 0.0 .
void | SetLocation (const gp_Pnt &P)
| Changes the location of the parabola. It is the vertex of the parabola. .
Standard_EXPORT void | SetPosition (const gp_Ax2 &A2)
| Changes the local coordinate system of the parabola. .
const gp_Ax1 & | Axis () const
| Returns the main axis of the parabola. It is the axis normal to the plane of the parabola passing through the vertex of the parabola. .
gp_Ax1 | Directrix () const

Computes the directrix of this 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_Ax1 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_Pnt | Focus () const

- Computes the focus of the parabola.

const gp_Pnt & | Location () const
| Returns the vertex of the parabola. It is the "Location" point of the coordinate system of the parabola. .
Standard_Real | Parameter () const
| Computes the parameter of the parabola. It is the distance between the focus and the directrix of the parabola. This distance is twice the focal length. .
const gp_Ax2 & | Position () const
| Returns the local coordinate system of the parabola. .
gp_Ax1 | XAxis () const
| Returns the symmetry axis of the parabola. The location point of the axis is the vertex of the parabola. .
gp_Ax1 | YAxis () const
| It is an axis parallel to the directrix of the parabola. The location point of this axis is the vertex of the parabola. .
Standard_EXPORT void | Mirror (const gp_Pnt &P)
Standard_EXPORT gp_Parab | Mirrored (const gp_Pnt &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_Ax1 &A1)
Standard_EXPORT gp_Parab | Mirrored (const gp_Ax1 &A1) const
| Performs the symmetrical transformation of a parabola with respect to an axis placement which is the axis of the symmetry. .
Standard_EXPORT void | Mirror (const gp_Ax2 &A2)
Standard_EXPORT gp_Parab | Mirrored (const gp_Ax2 &A2) const
| Performs the symmetrical transformation of a parabola with respect to a plane. The axis placement A2 locates the plane of the symmetry (Location, XDirection, YDirection). .
void | Rotate (const gp_Ax1 &A1, const Standard_Real Ang)
gp_Parab | Rotated (const gp_Ax1 &A1, const Standard_Real Ang) const
| Rotates a parabola. A1 is the axis of the rotation. Ang is the angular value of the rotation in radians. .
void | Scale (const gp_Pnt &P, const Standard_Real S)
gp_Parab | Scaled (const gp_Pnt &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_Trsf &T)
gp_Parab | Transformed (const gp_Trsf &T) const
| Transforms a parabola with the transformation T from class Trsf. .
void | Translate (const gp_Vec &V)
gp_Parab | Translated (const gp_Vec &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_Pnt &P1, const gp_Pnt &P2)
gp_Parab | Translated (const gp_Pnt &P1, const gp_Pnt &P2) const
| Translates a parabola from the point P1 to the point P2. .
const gp_Ax2 & | _CSFDB_Getgp_Parabpos () const
Standard_Real | _CSFDB_Getgp_ParabfocalLength () const
void | _CSFDB_Setgp_ParabfocalLength (const Standard_Real p)

## Private Attributes

gp_Ax2 | pos
Standard_Real | focalLength

## Friends

Standard_EXPORT friend Handle_Standard_Type & | gp_Parab_Type_ ()

## Constructor & Destructor Documentation

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

gp_Parab::gp_Parab | ( | const gp_Ax2 & | A2,
|  | const Standard_Real | Focal
| ) | `[inline]`

gp_Parab::gp_Parab | ( | const gp_Ax1 & | D,
|  | const gp_Pnt & | F
| ) | `[inline]`

## Member Function Documentation

Standard_Real gp_Parab::_CSFDB_Getgp_ParabfocalLength | ( |  | ) | const`[inline]`

const gp_Ax2& gp_Parab::_CSFDB_Getgp_Parabpos | ( |  | ) | const`[inline]`

void gp_Parab::_CSFDB_Setgp_ParabfocalLength | ( | const Standard_Real | p | ) | `[inline]`

const gp_Ax1 & gp_Parab::Axis | ( |  | ) | const`[inline]`

gp_Ax1 gp_Parab::Directrix | ( |  | ) | const`[inline]`

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

gp_Pnt gp_Parab::Focus | ( |  | ) | const`[inline]`

const gp_Pnt & gp_Parab::Location | ( |  | ) | const`[inline]`

Standard_EXPORT void gp_Parab::Mirror | ( | const gp_Ax2 & | A2 | ) |

Standard_EXPORT void gp_Parab::Mirror | ( | const gp_Ax1 & | A1 | ) |

Standard_EXPORT void gp_Parab::Mirror | ( | const gp_Pnt & | P | ) |

Standard_EXPORT gp_Parab gp_Parab::Mirrored | ( | const gp_Ax2 & | A2 | ) | const

Standard_EXPORT gp_Parab gp_Parab::Mirrored | ( | const gp_Ax1 & | A1 | ) | const

Standard_EXPORT gp_Parab gp_Parab::Mirrored | ( | const gp_Pnt & | P | ) | const

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

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

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

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

const gp_Ax2 & gp_Parab::Position | ( |  | ) | const`[inline]`

void gp_Parab::Rotate | ( | const gp_Ax1 & | A1,
|  | const Standard_Real | Ang
| ) | `[inline]`

gp_Parab gp_Parab::Rotated | ( | const gp_Ax1 & | A1,
|  | const Standard_Real | Ang
| ) | const`[inline]`

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

gp_Parab gp_Parab::Scaled | ( | const gp_Pnt & | P,
|  | const Standard_Real | S
| ) | const`[inline]`

void gp_Parab::SetAxis | ( | const gp_Ax1 & | A1 | ) | `[inline]`

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

void gp_Parab::SetLocation | ( | const gp_Pnt & | P | ) | `[inline]`

void gp_Parab::SetPosition | ( | const gp_Ax2 & | A2 | ) | `[inline]`

void gp_Parab::Transform | ( | const gp_Trsf & | T | ) | `[inline]`

gp_Parab gp_Parab::Transformed | ( | const gp_Trsf & | T | ) | const`[inline]`

void gp_Parab::Translate | ( | const gp_Pnt & | P1,
|  | const gp_Pnt & | P2
| ) | `[inline]`

void gp_Parab::Translate | ( | const gp_Vec & | V | ) | `[inline]`

gp_Parab gp_Parab::Translated | ( | const gp_Pnt & | P1,
|  | const gp_Pnt & | P2
| ) | const`[inline]`

gp_Parab gp_Parab::Translated | ( | const gp_Vec & | V | ) | const`[inline]`

gp_Ax1 gp_Parab::XAxis | ( |  | ) | const`[inline]`

gp_Ax1 gp_Parab::YAxis | ( |  | ) | const`[inline]`

## Friends And Related Function Documentation

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

## Field Documentation

Standard_Real gp_Parab::focalLength `[private]`

gp_Ax2 gp_Parab::pos `[private]`

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

- gp_Parab.hxx
- gp_Parab.lxx