fonttools/Lib/fontTools/varLib/interpolate_layout.py
2017-02-28 05:16:15 -08:00

117 lines
3.1 KiB
Python

"""
Interpolate OpenType Layout tables (GDEF / GPOS / GSUB).
"""
from __future__ import print_function, division, absolute_import
from fontTools.misc.py23 import *
from fontTools.ttLib import TTFont
from fontTools.varLib import designspace, models, VarLibError
from fontTools.varLib.merger import InstancerMerger
import os.path
def interpolate_layout(designspace_filename, loc, finder):
ds = designspace.load(designspace_filename)
axes = ds['axes'] if 'axes' in ds else []
if 'sources' not in ds or not ds['sources']:
raise VarLibError("no 'sources' defined in .designspace")
masters = ds['sources']
base_idx = None
for i,m in enumerate(masters):
if 'info' in m and m['info']['copy']:
assert base_idx is None
base_idx = i
assert base_idx is not None, "Cannot find 'base' master; Add <info> element to one of the masters in the .designspace document."
from pprint import pprint
print("Index of base master:", base_idx)
print("Building variable font")
print("Loading master fonts")
basedir = os.path.dirname(designspace_filename)
master_ttfs = [finder(os.path.join(basedir, m['filename'])) for m in masters]
master_fonts = [TTFont(ttf_path) for ttf_path in master_ttfs]
#font = master_fonts[base_idx]
font = TTFont(master_ttfs[base_idx])
master_locs = [o['location'] for o in masters]
axis_names = set(master_locs[0].keys())
assert all(axis_names == set(m.keys()) for m in master_locs)
# Set up axes
axes_dict = {}
if axes:
# the designspace file loaded had an <axes> element
for axis in axes:
default = axis['default']
lower = axis['minimum']
upper = axis['maximum']
name = axis['name']
axes_dict[name] = (lower, default, upper)
else:
for tag in axis_names:
default = master_locs[base_idx][tag]
lower = min(m[tag] for m in master_locs)
upper = max(m[tag] for m in master_locs)
if default == lower == upper:
continue
axes_dict[tag] = (lower, default, upper)
print("Axes:")
pprint(axes_dict)
print("Location:", loc)
print("Master locations:")
pprint(master_locs)
# Normalize locations
loc = models.normalizeLocation(loc, axes_dict)
master_locs = [models.normalizeLocation(m, axes_dict) for m in master_locs]
print("Normalized location:", loc)
print("Normalized master locations:")
pprint(master_locs)
# Assume single-model for now.
model = models.VariationModel(master_locs)
assert 0 == model.mapping[base_idx]
merger = InstancerMerger(font, model, loc)
print("Building variations tables")
merger.mergeTables(font, master_fonts, axes_dict, base_idx, ['GPOS'])
return font
def main(args=None):
import sys
if args is None:
args = sys.argv[1:]
designspace_filename = args[0]
locargs = args[1:]
outfile = os.path.splitext(designspace_filename)[0] + '-instance.ttf'
finder = lambda s: s.replace('master_ufo', 'master_ttf_interpolatable').replace('.ufo', '.ttf')
loc = {}
for arg in locargs:
tag,val = arg.split('=')
loc[tag] = float(val)
font = interpolate_layout(designspace_filename, loc, finder)
print("Saving font", outfile)
font.save(outfile)
if __name__ == "__main__":
import sys
if len(sys.argv) > 1:
sys.exit(main())
import doctest
sys.exit(doctest.testmod().failed)