Returns true if the parameter of the curve is periodic.

It is possible only if the curve is closed and if the

following relation is satisfied :

for each parametric value U the distance between the point

P(u) and the point P (u + T) is lower or equal to Resolution

from package gp, T is the period and must be a constant.

There are three possibilities :

. the curve is never periodic by definition (SegmentLine)

. the curve is always periodic by definition (Circle)

. the curve can be defined as periodic (BSpline). In this case

a function SetPeriodic allows you to give the shape of the

curve. The general rule for this case is : if a curve can be

periodic or not the default periodicity set is non periodic

and you have to turn (explicitly) the curve into a periodic

curve if you want the curve to be periodic.

Implemented in Bisector_BisecCC, Bisector_BisecPC, Geom2d_BezierCurve, Geom2d_BSplineCurve, Geom2d_Circle, Geom2d_Ellipse, Geom2d_Hyperbola, Geom2d_Line, Geom2d_OffsetCurve, Geom2d_Parabola, and Geom2d_TrimmedCurve.

Referenced by Period(), and MAT2d_Tool2d::Projection().