Module polygon 

Simple-polygon triangulation by ear clipping, with hole support.

Orientation is decided by the certified orient2d predicate rather than a raw sign test, so a near-degenerate vertex cannot silently flip a triangle.

Functions

ring_orientation

Orientation of a ring, or None when it encloses no certifiable area.

signed_area2

Twice the signed area of a closed ring. Positive means counter-clockwise.

triangulate_simple

Triangulate a simple CCW polygon by ear clipping.