noto-emoji/colrv1_add_soft_light_to_fl...

189 lines
5.4 KiB
Python

"""Utility to add soft-light effect to NotoColorEmoji-COLRv1 region flags."""
import sys
import subprocess
from fontTools import ttLib
from fontTools.ttLib.tables import otTables as ot
from fontTools.ttLib.tables.C_P_A_L_ import Color
from fontTools.colorLib.builder import LayerListBuilder
from add_aliases import read_default_emoji_aliases
from flag_glyph_name import flag_code_to_glyph_name
from map_pua_emoji import get_glyph_name_from_gsub
REGIONAL_INDICATOR_RANGE = range(0x1F1E6, 0x1F1FF + 1)
BLACK_FLAG = 0x1F3F4
CANCEL_TAG = 0xE007F
TAG_RANGE = range(0xE0000, CANCEL_TAG + 1)
def is_flag(sequence):
# regular region flags are comprised of regional indicators
if all(cp in REGIONAL_INDICATOR_RANGE for cp in sequence):
return True
# subdivision flags start with black flag, contain some tag characters and end with
# a cancel tag
if (
len(sequence) > 2
and sequence[0] == BLACK_FLAG
and sequence[-1] == CANCEL_TAG
and all(cp in TAG_RANGE for cp in sequence[1:-1])
):
return True
return False
def read_makefile_variable(var_name):
# see `print-%` command in Makefile
value = subprocess.run(
["make", f"print-{var_name}"], capture_output=True, check=True
).stdout.decode("utf-8")
return value[len(var_name) + len(" = ") :].strip()
def flag_code_to_sequence(flag_code):
# I use the existing code to first convert from flag code to glyph name,
# and then convert names back to integer codepoints since it already
# handles both the region indicators and subdivision tags.
name = flag_code_to_glyph_name(flag_code)
assert name.startswith("u")
return tuple(int(v, 16) for v in name[1:].split("_"))
def all_flag_sequences():
"""Return the set of all noto-emoji's region and subdivision flag sequences.
These include those in SELECTED_FLAGS Makefile variable plus those listed
in the 'emoji_aliases.txt' file.
"""
result = {
flag_code_to_sequence(flag_code)
for flag_code in read_makefile_variable("SELECTED_FLAGS").split()
}
result.update(seq for seq in read_default_emoji_aliases() if is_flag(seq))
return result
_builder = LayerListBuilder()
def _build_paint(source):
return _builder.buildPaint(source)
def _paint_composite(source, mode, backdrop):
return _build_paint(
{
"Format": ot.PaintFormat.PaintComposite,
"SourcePaint": source,
"CompositeMode": mode,
"BackdropPaint": backdrop,
}
)
def _palette_index(cpal, color):
assert len(cpal.palettes) == 1
palette = cpal.palettes[0]
try:
i = palette.index(color)
except ValueError:
i = len(palette)
palette.append(color)
cpal.numPaletteEntries += 1
assert len(palette) == cpal.numPaletteEntries
return i
WHITE = Color.fromHex("#FFFFFFFF")
GRAY = Color.fromHex("#808080FF")
BLACK = Color.fromHex("#000000FF")
def _soft_light_gradient(cpal):
return _build_paint(
{
"Format": ot.PaintFormat.PaintLinearGradient,
"ColorLine": {
"Extend": "pad",
"ColorStop": [
{
"StopOffset": 0.0,
"PaletteIndex": _palette_index(cpal, WHITE),
"Alpha": 0.5,
},
{
"StopOffset": 0.5,
"PaletteIndex": _palette_index(cpal, GRAY),
"Alpha": 0.5,
},
{
"StopOffset": 1.0,
"PaletteIndex": _palette_index(cpal, BLACK),
"Alpha": 0.5,
},
],
},
"x0": 47,
"y0": 790,
"x1": 890,
"y1": -342,
"x2": -1085,
"y2": -53,
},
)
def flag_ligature_glyphs(font):
"""Yield ligature glyph names for all the region/subdivision flags in the font."""
for flag_sequence in all_flag_sequences():
flag_name = get_glyph_name_from_gsub(flag_sequence, font)
if flag_name is not None:
yield flag_name
def add_soft_light_to_flags(font, flag_glyph_names=None):
"""Add soft-light effect to region and subdivision flags in CORLv1 font."""
if flag_glyph_names is None:
flag_glyph_names = flag_ligature_glyphs(font)
colr_glyphs = {
rec.BaseGlyph: rec
for rec in font["COLR"].table.BaseGlyphList.BaseGlyphPaintRecord
}
cpal = font["CPAL"]
for flag_name in flag_glyph_names:
flag = colr_glyphs[flag_name]
flag.Paint = _paint_composite(
source=_paint_composite(
source=_soft_light_gradient(cpal),
mode=ot.CompositeMode.SRC_IN,
backdrop=flag.Paint,
),
mode=ot.CompositeMode.SOFT_LIGHT,
backdrop=flag.Paint,
)
def main():
try:
input_file, output_file = sys.argv[1:]
except ValueError:
print("usage: colrv1_add_soft_light_to_flags.py INPUT_FONT OUTPUT_FONT")
return 2
font = ttLib.TTFont(input_file)
if "COLR" not in font or font["COLR"].version != 1:
print("error: missing required COLRv1 table")
return 1
add_soft_light_to_flags(font)
font.save(output_file)
if __name__ == "__main__":
sys.exit(main())