pens: Inspect and manipulate glyph outlines
Overview:
The fontTools pens are a collection of classes that can operate on a font glyph via the points and the contours of the glyph’s outlines.
Some pens trace through the outlines and generate graphical output, such as a new glyph outline or a formatted image, but other pens analyze the outlines and return information about the glyph.
Pens that alter or produce a pen-compatible ttGlyph object can
be chained together.
New pens can be written by sub-classing the AbstractPen or,
somewhat more practically, BasePen classes. The Pen Protocol is
documented on the basePen page.