Geom2d_Circle.hxx File Reference

#include <Standard.hxx>
#include <Standard_DefineHandle.hxx>
#include <Handle_Geom2d_Circle.hxx>
#include <Standard_Real.hxx>
#include <Geom2d_Conic.hxx>
#include <Handle_Geom2d_Conic.hxx>
#include <gp_Ax22d.hxx>
#include <Geom2d_Curve.hxx>
#include <GeomAbs_Shape.hxx>
#include <Standard_Boolean.hxx>
#include <Standard_Integer.hxx>
#include <Handle_Geom2d_Geometry.hxx>

Data Structures

class Geom2d_Circle

Describes a circle in the plane (2D space).
A circle is defined by its radius and, as with any conic
curve, is positioned in the plane with a coordinate
system (gp_Ax22d object) where the origin is the
center of the circle.
The coordinate system is the local coordinate
system of the circle.
The orientation (direct or indirect) of the local
coordinate system gives an explicit orientation to the
circle, determining the direction in which the
parameter increases along the circle.
The Geom2d_Circle circle is parameterized by an angle:
P(U) = O + R*Cos(U)*XDir + R*Sin(U)*YDir
where:

P is the point of parameter U,
O, XDir and YDir are respectively the origin, "X <br> Direction" and "Y Direction" of its local coordinate system,
R is the radius of the circle.
The "X Axis" of the local coordinate system therefore
defines the origin of the parameter of the circle. The
parameter is the angle with this "X Direction".
A circle is a closed and periodic curve. The period is
2.*Pi and the parameter range is [ 0,2.*Pi [.
See Also
GCE2d_MakeCircle which provides functions for
more complex circle constructions
gp_Ax22d and gp_Circ2d for an equivalent, non-parameterized data structure.

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