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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:
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