Module fields 

Building blocks of the forms of what is drawn in a sketch, here and in a 3-D sketch: a filled region, how a sketch’s constraints stand.

Functions

constraint_status

How a sketch’s constraints stand, followed by what it draws, drawn: how many conflict, unless all hold (converged), and then whether the sketch is fully constrained or how many degrees of freedom it has left.

region

The area of plane’s u/v plane inside outer but outside holes, as triangles — to draw a region filled. No triangles for loops that do not triangulate.