# Boundaries

Boundary shapes, introduced in {doc}`../boundaries/shapes`. Boundary, string
and layout modifiers are grouped under {mod}`oowl.modifiers`.

Generated boundaries take `area` as their size in square meters, and shape
arguments such as rectangle width and height or ellipse semi-axes fix only
proportions. `Polygon` keeps its source coordinates unless `area` or `center`
is given. Modifiers may change the area and centroid afterwards.

```{eval-rst}
.. currentmodule:: oowl.boundaries

.. autosummary::

   Boundary
   Union
   Polygon
   Rectangle
   Square
   RegularPolygon
   Circle
   Ellipse
   Annulus
   RadialPolygon
   RandomRadialPolygon
   SmoothBlob
   ConvexHull
   FourierPolygon
   OffshorePolygon
   Composite
```

```{eval-rst}
.. automodule:: oowl.boundaries
   :members:
```