3DLDF currently includes the following classes representing plane
geometric figures: `Polygon`

, `Reg_Cl_Plane_Curve`

("Regular Closed Plane Curve"), `Reg_Polygon`

("Regular
Polygon"), `Rectangle`

, `Ellipse`

and
`Circle`

. `Polygon`

and `Reg_Cl_Plane_Curve`

are derived
from `Path`

, `Reg_Polygon`

and `Rectangle`

are derived
from `Polygon`

, and `Ellipse`

and `Circle`

are derived
from `Reg_Cl_Plane_Curve`

. `Polygon`

and
`Reg_Cl_Plane_Curve`

are meant to be used as base classes only, so
objects of these types should normally never be declared.

Since `Reg_Polygon`

, `Rectangle`

, `Ellipse`

, and
`Circle`

all ultimately derive from `Path`

, they are really
just special kinds of `Path`

.
In particular, they inherit their drawing and filling functions from
`Path`

, and their transformation functions take the same arguments
as the `Path`

versions.
They also have constructors
and setting functions that work in a similar way, with a few minor
differences, to account for their different natures.
See Polygon Reference, Rectangle Reference,
Ellipse Reference, and Circle Reference, for complete
information on these classes.