Public 成员函数
	GParab ()

	GParab (GAx2 theA2, double theFocal)

	GParab (GAx1 theD, GPnt theF)

void	SetAxis (GAx1 theA1)

void	SetFocal (double theFocal)

void	SetLocation (GPnt theP)

void	SetPosition (GAx2 theA2)

GAx1	Axis ()

GAx1	Directrix ()

double	Focal ()

GPnt	Focus ()

GPnt	Location ()

double	Parameter ()

GAx2	Position ()

GAx1	XAxis ()

GAx1	YAxis ()

void	Mirror (GPnt theP)

GParab	Mirrored (GPnt theP)

void	Mirror (GAx1 theA1)

GParab	Mirrored (GAx1 theA1)

void	Mirror (GAx2 theA2)

GParab	Mirrored (GAx2 theA2)

void	Rotate (GAx1 theA1, double theAng)

GParab	Rotated (GAx1 theA1, double theAng)

void	Scale (GPnt theP, double theS)

GParab	Scaled (GPnt theP, double theS)

void	Transform (GTrsf theT)

GParab	Transformed (GTrsf theT)

void	Translate (GVec theV)

GParab	Translated (GVec theV)

void	Translate (GPnt theP1, GPnt theP2)

GParab	Translated (GPnt theP1, GPnt theP2)

详细描述

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

构造及析构函数说明

◆ GParab() [1/3]

GParab.GParab ( )

Creates an indefinite Parabola.

◆ GParab() [2/3]

GParab.GParab	(	GAx2	theA2,
		double	theFocal
	)

Creates a parabola with its local coordinate system "theA2" and it's focal length "Focal". The XDirection of theA2 defines the axis of symmetry of the parabola. The YDirection of theA2 is parallel to the directrix of the parabola. The Location point of theA2 is the vertex of the parabola Raises ConstructionError if theFocal < 0.0 Raised if theFocal < 0.0

◆ GParab() [3/3]

GParab.GParab	(	GAx1	theD,
		GPnt	theF
	)

theD is the directrix of the parabola and theF the focus point. The symmetry axis (XAxis) of the parabola is normal to the directrix and pass through the focus point theF, but its location point is the vertex of the parabola. The YAxis of the parabola is parallel to theD 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.

成员函数说明

◆ Axis()

GAx1 GParab.Axis ( )

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.

◆ Directrix()

GAx1 GParab.Directrix ( )

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.

◆ Focal()

double GParab.Focal ( )

Returns the distance between the vertex and the focus of the parabola.

◆ Focus()

GPnt GParab.Focus ( )

Computes the focus of the parabola.

◆ Location()

GPnt GParab.Location ( )

Returns the vertex of the parabola. It is the "Location" point of the coordinate system of the parabola.

◆ Mirrored() [1/3]

GParab GParab.Mirrored ( GAx1 theA1 )

Performs the symmetrical transformation of a parabola with respect to an axis placement which is the axis of the symmetry.

◆ Mirrored() [2/3]

GParab GParab.Mirrored ( GAx2 theA2 )

Performs the symmetrical transformation of a parabola with respect to a plane. The axis placement theA2 locates the plane of the symmetry (Location, XDirection, YDirection).

◆ Mirrored() [3/3]

GParab GParab.Mirrored ( GPnt theP )

Performs the symmetrical transformation of a parabola with respect to the point theP which is the center of the symmetry.

◆ Parameter()

double GParab.Parameter ( )

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.

◆ Position()

GAx2 GParab.Position ( )

Returns the local coordinate system of the parabola.

◆ Rotated()

GParab GParab.Rotated	(	GAx1	theA1,
		double	theAng
	)

Rotates a parabola. theA1 is the axis of the rotation. Ang is the angular value of the rotation in radians.

◆ Scaled()

GParab GParab.Scaled	(	GPnt	theP,
		double	theS
	)

Scales a parabola. theS is the scaling value. If theS is negative the direction of the symmetry axis XAxis is reversed and the direction of the YAxis too.

◆ SetAxis()

void GParab.SetAxis ( GAx1 theA1 )

Modifies this parabola by redefining its local coordinate system so that - its origin and "main Direction" become those of the axis theA1 (the "X Direction" and "Y Direction" are then recomputed in the same way as for any gp_Ax2) Raises ConstructionError if the direction of theA1 is parallel to the previous XAxis of the parabola.

◆ SetFocal()

void GParab.SetFocal ( double theFocal )

Changes the focal distance of the parabola. Raises ConstructionError if theFocal < 0.0

◆ SetLocation()

void GParab.SetLocation ( GPnt theP )

Changes the location of the parabola. It is the vertex of the parabola.

◆ SetPosition()

void GParab.SetPosition ( GAx2 theA2 )

Changes the local coordinate system of the parabola.

◆ Transformed()

GParab GParab.Transformed ( GTrsf theT )

Transforms a parabola with the transformation theT from class Trsf.

◆ Translated() [1/2]

GParab GParab.Translated	(	GPnt	theP1,
		GPnt	theP2
	)

Translates a parabola from the point theP1 to the point theP2.

◆ Translated() [2/2]

GParab GParab.Translated ( GVec theV )

Translates a parabola in the direction of the vector theV. The magnitude of the translation is the vector's magnitude.

◆ XAxis()

GAx1 GParab.XAxis ( )

Returns the symmetry axis of the parabola. The location point of the axis is the vertex of the parabola.

◆ YAxis()

GAx1 GParab.YAxis ( )

It is an axis parallel to the directrix of the parabola. The location point of this axis is the vertex of the parabola.

Public 成员函数