blob: 826b6bbaf02e242dee5bc5225253e09e02bbc012 [file] [log] [blame]
# Copyright 2020 Google LLC
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
"""Utility to generate codepoint files for Google-style iconfonts."""
from fontTools import ttLib
import functools
from pathlib import Path
_PUA_CODEPOINTS = [
range(0xE000, 0xF8FF + 1),
range(0xF0000, 0xFFFFD + 1),
range(0x100000, 0x10FFFD + 1)
]
def _is_pua(codepoint):
return any(r for r in _PUA_CODEPOINTS if codepoint in r)
def _cmap(ttfont):
def _cmap_reducer(acc, u):
acc.update(u)
return acc
unicode_cmaps = (t.cmap for t in ttfont['cmap'].tables if t.isUnicode())
return functools.reduce(_cmap_reducer, unicode_cmaps, {})
def _LookupSubtablesOfType(lookup_list, lookup_type):
# Direct matches
for lookup in lookup_list.Lookup:
if lookup.LookupType == lookup_type:
for subtable in lookup.SubTable:
yield subtable
def _ligatures(ttfont):
lookup_list = ttfont['GSUB'].table.LookupList
# Direct ligatures
for subtable in _LookupSubtablesOfType(lookup_list, 4):
yield subtable.ligatures
# Extensions
for ext_subtable in _LookupSubtablesOfType(lookup_list, 7):
if ext_subtable.ExtensionLookupType == 4:
yield ext_subtable.ExtSubTable.ligatures
def enumerate(font_file: Path):
"""Yields (icon name, codepoint) tuples for icon font."""
with ttLib.TTFont(font_file) as ttfont:
cmap = _cmap(ttfont)
rev_cmap = {v: k for k, v in cmap.items()}
for lig_root in _ligatures(ttfont):
for first_glyph_name, ligatures in lig_root.items():
for ligature in ligatures:
glyph_names = (first_glyph_name,) + tuple(ligature.Component)
icon_name = ''.join(chr(rev_cmap[n]) for n in glyph_names)
codepoint = rev_cmap[ligature.LigGlyph]
if not _is_pua(codepoint):
continue
yield (icon_name, codepoint)