The function polygon_area_2 computes the signed area of a polygon.
Computes the signed area of the polygon defined by the range of points
The sign is positive for counterclockwise polygons, negative for
clockwise polygons. If the polygon is not simple, the area is not well defined.
template <class ForwardIterator, class Traits>
polygon_area_2 ( ForwardIterator first, ForwardIterator last, Traits traits)
- Traits is a model of the concept
Only the following members of this traits class are used:
- Compute_area_2 : Computes the signed area of the
oriented triangle defined by 3 Point_2 passed as arguments.
- ForwardIterator::value_type should be Traits::Point_2,