colrv1_postproc.py: handle missing regional indicators in noflags font

don't bother to do textwrap.dedent, as whitespace doesn't matter in FEA code
pull/378/head
Cosimo Lupo 2022-02-03 19:07:42 +00:00
parent ec10159d1f
commit 083b7fcad7
1 changed files with 29 additions and 27 deletions

View File

@ -5,7 +5,6 @@ For now substantially based on copying from a correct bitmap build.
"""
from absl import app
import functools
from textwrap import dedent
from fontTools.feaLib.builder import addOpenTypeFeaturesFromString
from fontTools import ttLib
from fontTools.ttLib.tables import _g_l_y_f as glyf
@ -199,55 +198,58 @@ def _add_fallback_subs_for_unknown_flags(colr_font):
black_flag = cmap[BLACK_FLAG]
cancel_tag = cmap[CANCEL_TAG]
flag_tags = sorted(cmap[cp] for cp in FLAG_TAGS)
regional_indicators = sorted(cmap[cp] for cp in REGIONAL_INDICATORS)
# in the *-noflags.ttf font there are no region flags thus this list is empty
regional_indicators = sorted(cmap[cp] for cp in REGIONAL_INDICATORS if cp in cmap)
classes = dedent(
f"""\
@FLAG_TAGS = [{" ".join(flag_tags)}];
classes = f'@FLAG_TAGS = [{" ".join(flag_tags)}];\n'
if regional_indicators:
classes += f"""
@REGIONAL_INDICATORS = [{" ".join(regional_indicators)}];
@UNKNOWN_FLAG = [{" ".join([unknown_flag] * len(regional_indicators))}];
"""
)
lookups = (
# the first lookup is a dummy that stands for the emoji sequences ligatures
# from the destination font; we only use it to ensure the lookup indices match.
# We can't leave it empty otherwise feaLib optimizes it away.
dedent(
f"""\
f"""
lookup placeholder {{
sub {unknown_flag} {unknown_flag} by {unknown_flag};
}} placeholder;
"""
)
+ "\n".join(
["lookup delete_glyph {"]
+ [f" sub {g} by NULL;" for g in sorted(regional_indicators + flag_tags)]
+ ["} delete_glyph;"]
)
+ "\n"
+ dedent(
"""\
+ (
"""
lookup replace_with_unknown_flag {
sub @REGIONAL_INDICATORS by @UNKNOWN_FLAG;
} replace_with_unknown_flag;
"""
if regional_indicators
else "\n"
)
)
features = (
"languagesystem DFLT dflt;\n"
+ classes
+ lookups
+ dedent(
f"""\
feature ccmp {{
+ "feature ccmp {"
+ f"""
lookup placeholder;
sub {black_flag} @FLAG_TAGS' lookup delete_glyph;
sub {black_flag} {cancel_tag} by {unknown_flag};
"""
+ (
"""
sub @REGIONAL_INDICATORS' lookup replace_with_unknown_flag
@REGIONAL_INDICATORS' lookup delete_glyph;
}} ccmp;
"""
if regional_indicators
else ""
)
+ "} ccmp;"
)
# feaLib always builds a new GSUB table (can't update one in place) so we have to
# use an empty TTFont and then update our GSUB with the newly built lookups