List/count tuple variation regions in gvar table

list_vf_regions.py

import sys
import pprint
from collections import OrderedDict, Counter

import fontTools
from fontTools import ttLib


log = fontTools.log


def get_gvar_regions(vfont):
    locs = Counter()
    axisOrder = [a.axisTag for a in vfont["fvar"].axes]
    gvar = vfont["gvar"]
    for glyphname, variations in gvar.variations.items():
        for tv in variations:
            locs[
                (
                    tuple(
                        tuple(i) for i in sorted(
                            tv.axes.items(), key=lambda i: axisOrder.index(i[0])
                        )
                    )
                )
            ] += 1
    return locs


def main():
    fontfiles = sys.argv[1:]
    if not fontfiles:
        sys.exit("usage: list_vf_regions.py font.ttf [font2.ttf ...]")

    fontTools.configLogger(level="INFO")

    for fontfile in fontfiles:
        vfont = ttLib.TTFont(fontfile)
        if "gvar" not in vfont:
            log.warning("%s is not a truetype variable font, skipped", fontfile)
        regions = get_gvar_regions(vfont)
        log.info(
            "%s: %d\n%s",
            fontfile,
            len(regions),
            pprint.pformat(dict(regions))
        )


if __name__ == "__main__":
    main()