The main methods for conversion are found in
Intermediate data can be accessed without actually writing UFOs, if
Write and return UFOs
The following code will write UFOs and a Designspace file to disk.
import glyphsLib master_dir = 'master_ufos' ufos, designspace_path = glyphsLib.build_masters('MyFont.glyphs', master_dir)
If you want to interpolate instances, please use fontmake instead. It uses this library under the hood when dealing with Glyphs files.
Load UFO objects without writing
import glyphsLib ufos = glyphsLib.load_to_ufos('MyFont.glyphs')
Read and write Glyphs data as Python objects
from glyphsLib import GSFont font = GSFont(glyphs_file) font.save(glyphs_file)
glyphsLib.classes module aims to provide an interface similar to
Glyphs.app's Python Scripting API.
Note that currently not all the classes and methods may be fully implemented. We try to keep up to date, but if you find something that is missing or does not work as expected, please open a issue.
Go back and forth between UFOs and Glyphs
You can use the
glyphs2ufocommand line scripts to round-trip your source files. By default, the scripts try to preserve as much metadata as possible.
# Generate master UFOs and Designspace file glyphs2ufo Example.glyphs # Go back ufo2glyphs Example.designspace # You can also combine single UFOs into a Glyphs source file. ufo2glyphs Example-Regular.ufo Example-Bold.ufo
Without a designspace file, using for example the Inria fonts by Black[Foundry]:
import glob from defcon import Font from glyphsLib import to_glyphs ufos = [Font(path) for path in glob.glob('*Italic.ufo')] # Sort the UFOs because glyphsLib will create masters in the same order ufos = sorted(ufos, key=lambda ufo: ufo.info.openTypeOS2WeightClass) font = to_glyphs(ufos) font.save('InriaSansItalic.glyphs')
With a designspace, using Spectral from Production Type:
import glob from fontTools.designspaceLib import DesignSpaceDocument from glyphsLib import to_glyphs doc = DesignSpaceDocument() doc.read('spectral-build-roman.designspace') font = to_glyphs(doc) font.save('SpectralRoman.glyphs')
In both programmatic cases, if you intend to go back to UFOs after modifying the file with Glyphs, you should use the
minimize_ufo_diffsparameter to minimize the amount of diffs that will show up in git after the back and forth. To do so, the glyphsLib will add some bookkeeping values in various
userDatafields. For example, it will try to remember which GSClass came from groups.plist or from the feature file.
The same option exists for people who want to do Glyphs->UFOs->Glyphs:
minimize_glyphs_diffs, which will add some bookkeeping data in UFO
For example, it will keep the same UUIDs for Glyphs layers, and so will need
to store those layer UUIDs in the UFOs.
import glob import os from fontTools.designspaceLib import DesignSpaceDocument from glyphsLib import to_glyphs, to_designspace, GSFont doc = DesignSpaceDocument() doc.read('spectral-build-roman.designspace') font = to_glyphs(doc, minimize_ufo_diffs=True) doc2 = to_designspace(font, propagate_anchors=False) # UFOs are in memory only, attached to the doc via `sources` # Writing doc2 over the original doc should generate very few git diffs (ideally none) doc2.write(doc.path) for source in doc2.sources: path = os.path.join(os.path.dirname(doc.path), source.filename) # You will want to use ufoNormalizer after source.font.save(path) font = GSFont('SpectralRoman.glyphs') doc = to_designspace(font, minimize_glyphs_diffs=True, propagate_anchors=False) font2 = to_glyphs(doc) # Writing font2 over font should generate very few git diffs (ideally none): font2.save(font.filepath)
In practice there are always a few diffs on things that don't really make a difference, like optional things being added/removed or whitespace changes or things getting reordered...