Public 成员函数
	GParab2d ()

	GParab2d (GAx2d theMirrorAxis, double theFocalLength, boolean theSense)

	GParab2d (GAx2d theMirrorAxis, double theFocalLength)

	GParab2d (GAx22d theAxes, double theFocalLength)

	GParab2d (GAx2d theDirectrix, GPnt2d theFocus, boolean theSense)

	GParab2d (GAx2d theDirectrix, GPnt2d theFocus)

void	SetFocal (double theFocal)

void	SetLocation (GPnt2d theP)

void	SetMirrorAxis (GAx2d theA)

void	SetAxis (GAx22d theA)

void	Coefficients (double[] theA, double[] theB, double[] theC, double[] theD, double[] theE, double[] theF)

GAx2d	Directrix ()

double	Focal ()

GPnt2d	Focus ()

GPnt2d	Location ()

GAx2d	MirrorAxis ()

GAx22d	Axis ()

double	Parameter ()

void	Reverse ()

GParab2d	Reversed ()

boolean	IsDirect ()

void	Mirror (GPnt2d theP)

GParab2d	Mirrored (GPnt2d theP)

void	Mirror (GAx2d theA)

GParab2d	Mirrored (GAx2d theA)

void	Rotate (GPnt2d theP, double theAng)

GParab2d	Rotated (GPnt2d theP, double theAng)

void	Scale (GPnt2d theP, double theS)

GParab2d	Scaled (GPnt2d theP, double theS)

void	Transform (GTrsf2d theT)

GParab2d	Transformed (GTrsf2d theT)

void	Translate (GVec2d theV)

GParab2d	Translated (GVec2d theV)

void	Translate (GPnt2d theP1, GPnt2d theP2)

GParab2d	Translated (GPnt2d theP1, GPnt2d theP2)

详细描述

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

构造及析构函数说明

◆ GParab2d() [1/6]

GParab2d.GParab2d ( )

Creates an indefinite parabola.

◆ GParab2d() [2/6]

GParab2d.GParab2d	(	GAx2d	theMirrorAxis,
		double	theFocalLength,
		boolean	theSense
	)

Creates a parabola with its vertex point, its axis of symmetry ("XAxis") and its focal length. The sense of parametrization is given by theSense. If theSense == TRUE (by default) then right-handed coordinate system is used, otherwise - left-handed. Warnings : It is possible to have FocalLength = 0. In this case, the parabola looks like a line, which is parallel to the symmetry-axis. Raises ConstructionError if FocalLength < 0.0

◆ GParab2d() [3/6]

GParab2d.GParab2d	(	GAx2d	theMirrorAxis,
		double	theFocalLength
	)

Creates a parabola with its vertex point, its axis of symmetry ("XAxis") and its focal length. The sense of parametrization is given by theSense. If theSense == TRUE (by default) then right-handed coordinate system is used, otherwise - left-handed. Warnings : It is possible to have FocalLength = 0. In this case, the parabola looks like a line, which is parallel to the symmetry-axis. Raises ConstructionError if FocalLength < 0.0

◆ GParab2d() [4/6]

GParab2d.GParab2d	(	GAx22d	theAxes,
		double	theFocalLength
	)

Creates a parabola with its vertex point, its axis of symmetry ("XAxis"), correspond Y-axis and its focal length. Warnings : It is possible to have FocalLength = 0. In this case, the parabola looks like a line, which is parallel to the symmetry-axis. Raises ConstructionError if Focal < 0.0

◆ GParab2d() [5/6]

GParab2d.GParab2d	(	GAx2d	theDirectrix,
		GPnt2d	theFocus,
		boolean	theSense
	)

Creates a parabola with the directrix and the focus point. Y-axis of the parabola (in User Coordinate System - UCS) is the direction of theDirectrix. X-axis always directs from theDirectrix to theFocus point and always comes through theFocus. Apex of the parabola is a middle point between the theFocus and the intersection point of theDirectrix and the X-axis. Warnings : It is possible to have FocalLength = 0 (when theFocus lies in theDirectrix). In this case, X-direction of the parabola is defined by theSense parameter. If theSense == TRUE (by default) then right-handed coordinate system is used, otherwise - left-handed. Result parabola will look like a line, which is perpendicular to the directrix.

◆ GParab2d() [6/6]

GParab2d.GParab2d	(	GAx2d	theDirectrix,
		GPnt2d	theFocus
	)

Creates a parabola with the directrix and the focus point. Y-axis of the parabola (in User Coordinate System - UCS) is the direction of theDirectrix. X-axis always directs from theDirectrix to theFocus point and always comes through theFocus. Apex of the parabola is a middle point between the theFocus and the intersection point of theDirectrix and the X-axis. Warnings : It is possible to have FocalLength = 0 (when theFocus lies in theDirectrix). In this case, X-direction of the parabola is defined by theSense parameter. If theSense == TRUE (by default) then right-handed coordinate system is used, otherwise - left-handed. Result parabola will look like a line, which is perpendicular to the directrix.

成员函数说明

◆ Axis()

GAx22d GParab2d.Axis ( )

Returns the local coordinate system of the parabola. The "Location" point of this axis is the vertex of the parabola.

◆ Coefficients()

void GParab2d.Coefficients	(	double[]	theA,
		double[]	theB,
		double[]	theC,
		double[]	theD,
		double[]	theE,
		double[]	theF
	)

Computes the coefficients of the implicit equation of the parabola (in WCS - World Coordinate System). theA * (X**2) + theB * (Y**2) + 2*theC*(X*Y) + 2*theD*X + 2*theE*Y + theF = 0.

◆ Directrix()

GAx2d GParab2d.Directrix ( )

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.

◆ Focal()

double GParab2d.Focal ( )

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

◆ Focus()

GPnt2d GParab2d.Focus ( )

Returns the focus of the parabola.

◆ IsDirect()

boolean GParab2d.IsDirect ( )

Returns true if the local coordinate system is direct and false in the other case.

◆ Location()

GPnt2d GParab2d.Location ( )

Returns the vertex of the parabola.

◆ MirrorAxis()

GAx2d GParab2d.MirrorAxis ( )

Returns the symmetry axis of the parabola. The "Location" point of this axis is the vertex of the parabola.

◆ Mirrored() [1/2]

GParab2d GParab2d.Mirrored ( GAx2d theA )

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

◆ Mirrored() [2/2]

GParab2d GParab2d.Mirrored ( GPnt2d theP )

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

◆ Parameter()

double GParab2d.Parameter ( )

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

◆ Reversed()

GParab2d GParab2d.Reversed ( )

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.

◆ Rotated()

GParab2d GParab2d.Rotated	(	GPnt2d	theP,
		double	theAng
	)

Rotates a parabola. theP is the center of the rotation. theAng is the angular value of the rotation in radians.

◆ Scaled()

GParab2d GParab2d.Scaled	(	GPnt2d	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 GParab2d.SetAxis ( GAx22d theA )

Changes the local coordinate system of the parabola. The "Location" point of A becomes the vertex of the parabola.

◆ SetFocal()

void GParab2d.SetFocal ( double theFocal )

Changes the focal distance of the parabola Warnings : It is possible to have theFocal = 0. Raises ConstructionError if theFocal < 0.0

◆ SetLocation()

void GParab2d.SetLocation ( GPnt2d theP )

Changes the "Location" point of the parabola. It is the vertex of the parabola.

◆ SetMirrorAxis()

void GParab2d.SetMirrorAxis ( GAx2d theA )

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.

◆ Transformed()

GParab2d GParab2d.Transformed ( GTrsf2d theT )

Transforms an parabola with the transformation theT from class Trsf2d.

◆ Translated() [1/2]

GParab2d GParab2d.Translated	(	GPnt2d	theP1,
		GPnt2d	theP2
	)

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

◆ Translated() [2/2]

GParab2d GParab2d.Translated ( GVec2d theV )

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

Public 成员函数