Open6
twemoji-colrから[*#0-9]を取り除く
たつおNot showing numbers on input like 1 , 2, 3 using this font family. · Issue #56 · mozilla/twemoji-colr
のIssueで議論されている．原因は，Twemoji側で[*#0-9]の範囲のグリフに全角の透明な文字が割り当てられているからである．
Twemojiでは，0 + 青い四角 を入力したときに出力が0️⃣に置換される．これはリガチャの一種(Emoji ZWJ Sequence)が用いられている．疑問として，コードポイントだけわかっていれば合成先を用意できそうというのがある．レイヤーを重ねるが，実際に使用されている0のグリフはレイヤーで指定されていて，特に必要ではないと思われる．
本問題を解決するためには，主に2つのアプローチが考えられる．1つ目は当該コードを書き換える方法である．これは本質的な解決であるが，少々手間である．2つ目は生成したフォントから不要なグリフを削除する方法である．こちらは対症療法的であるが，手軽だと考えられる．
たつお実は®と©も壊れてそう
たつお本投稿では2つ目の方法である，生成したフォントから不要なグリフを削除する方法を検討する．
Pythonのfonttoolsを用いる．
program
from fontTools import ttLib
from fontTools import subset
def load_twemoji() -> ttLib.TTFont:
return ttLib.TTFont(
"Twemoji.Mozilla.ttf"
)
def delete_especial_chars(gryphs: list) -> list:
drop_gryphs = [
0x0023, # #
0x002A, # *
0x0030, # 0
0x0031, # 1
0x0032, # 2
0x0033, # 3
0x0034, # 4
0x0035, # 5
0x0036, # 6
0x0037, # 7
0x0038, # 8
0x0039, # 9
]
for gryph in drop_gryphs:
gryphs.remove(gryph)
print(gryphs[:20])
return gryphs
def get_subset(font: ttLib.TTFont, gryphs: list) -> ttLib.TTFont:
options = subset.Options()
options.set(layout_features="*", name_IDs="*", name_legacy=True, name_languages="*")
subsetter = subset.Subsetter()
# subsetter.populate(gids=gryphs)
print(gryphs)
subsetter.populate(gids=gryphs)
subsetter.subset(font)
return font
def get_charset(font: ttLib.TTFont) -> list:
return list(font.getBestCmap().keys())
def save_font(font: ttLib.TTFont, path: str):
font.save(path)
def main():
font = load_twemoji()
gryphs = get_charset(font)
print(gryphs[:20])
completed_gryphs = delete_especial_chars(gryphs)
subset = get_subset(font, completed_gryphs)
save_font(subset, "Twemoji.Mozilla.subset.ttf")
if __name__ == "__main__":
main()
def delete_especial_chars(gryphs: list) -> list:
drop_gryphs = [
0x0023, # #
0x002A, # *
0x0030, # 0
0x0031, # 1
0x0032, # 2
0x0033, # 3
0x0034, # 4
0x0035, # 5
0x0036, # 6
0x0037, # 7
0x0038, # 8
0x0039, # 9
]
for gryph in drop_gryphs:
gryphs.remove(gryph)
return gryphs
とすると，
error message
fontTools.subset.Subsetter.MissingGlyphsSubsettingError: {917602, 917603, 917605, 917607, 917612, 917614, 917619, 917620, 917623, 917631, 58634, 126980, 127183, 127344, 127345, 127358, 127359, 127374, 127377, 127378, 127379, 127380, 127381, 127382, 127383, 127384, 127385, 127386, 127462, 127463, 127464, 127465, 127466, 127467, 127468, 127469, 127470, 127471, 127472, 127473, 127474, 127475, 127476, 127477, 127478, 127479, 127480, 127481, 127482, 127483, 127484, 127485, 127486, 127487, 127489, 127490, 127514, 127535, 127538, 127539, 127540, 127541, 127542, 127543, 127544, 127545, 127546, 127568, 127569, 127744, 127745, 127746, 127747, 127748, 127749, 127750, 127751, 127752, 127753, 127754, 127755, 127756, 127757, 127758, 127759, 127760, 127761, 127762, 127763, 127764, 127765, 127766, 127767, 127768, 127769, 127770, 127771, 127772, 127773, 127774, 127775, 127776, 127777, 127780, 127781, 127782, 127783, 127784, 127785, 127786, 127787, 127788, 127789, 127790, 127791, 127792, 127793, 127794, 127795, 127796, 127797, 127798, 127799, 127800, 127801, 127802, 127803, 127804, 127805, 127806, 127807, 127808, 127809, 127810, 127811, 127812, 127813, 127814, 127815, 127816, 127817, 127818, 127819, 127820, 127821, 127822, 127823, 127824, 127825, 127826, 127827, 127828, 127829, 127830, 127831, 127832, 127833, 127834, 127835, 127836, 127837, 127838, 127839, 127840, 127841, 127842, 127843, 127844, 127845, 127846, 127847, 127848, 127849, 127850, 127851, 127852, 127853, 127854, 127855, 127856, 127857, 127858, 127859, 127860, 127861, 127862, 127863, 127864, 127865, 127866, 127867, 127868, 127869, 127870, 127871, 127872, 127873, 127874, 127875, 127876, 127877, 127878, 127879, 127880, 127881, 127882, 127883, 127884, 127885, 127886, 127887, 127888, 127889, 127890, 127891, 127894, 127895, 127897, 127898, 127899, 127902, 127903, 127904, 127905, 127906, 127907, 127908, 127909, 127910, 127911, 127912, 127913, 127914, 127915, 127916, 127917, 127918, 127919, 127920, 127921, 127922, 127923, 127924, 127925, 127926, 127927, 127928, 127929, 127930, 127931, 127932, 127933, 127934, 127935, 127936, 127937, 127938, 127939, 127940, 127941, 127942, 127943, 127944, 127945, 127946, 127947, 127948, 127949, 127950, 127951, 127952, 127953, 127954, 127955, 127956, 127957, 127958, 127959, 127960, 127961, 127962, 127963, 127964, 127965, 127966, 127967, 127968, 127969, 127970, 127971, 127972, 127973, 127974, 127975, 127976, 127977, 127978, 127979, 127980, 127981, 127982, 127983, 127984, 127987, 127988, 127989, 127991, 127992, 127993, 127994, 127995, 127996, 127997, 127998, 127999, 128000, 128001, 128002, 128003, 128004, 128005, 128006, 128007, 128008, 128009, 128010, 128011, 128012, 128013, 128014, 128015, 128016, 128017, 128018, 128019, 128020, 128021, 128022, 128023, 128024, 128025, 128026, 128027, 128028, 128029, 128030, 128031, 128032, 128033, 128034, 128035, 128036, 128037, 128038, 128039, 128040, 128041, 128042, 128043, 128044, 128045, 128046, 128047, 128048, 128049, 128050, 128051, 128052, 128053, 128054, 128055, 128056, 128057, 128058, 128059, 128060, 128061, 128062, 128063, 128064, 128065, 128066, 128067, 128068, 128069, 128070, 128071, 128072, 128073, 128074, 128075, 128076, 128077, 128078, 128079, 128080, 128081, 128082, 128083, 128084, 128085, 128086, 128087, 128088, 128089, 128090, 128091, 128092, 128093, 128094, 128095, 128096, 128097, 128098, 128099, 128100, 128101, 128102, 128103, 128104, 128105, 128106, 128107, 128108, 128109, 128110, 128111, 128112, 128113, 128114, 128115, 128116, 128117, 128118, 128119, 128120, 128121, 128122, 128123, 128124, 128125, 128126, 128127, 128128, 128129, 128130, 128131, 128132, 128133, 128134, 128135, 128136, 128137, 128138, 128139, 128140, 128141, 128142, 128143, 128144, 128145, 128146, 128147, 128148, 128149, 128150, 128151, 128152, 128153, 128154, 128155, 128156, 128157, 128158, 128159, 128160, 128161, 128162, 128163, 128164, 128165, 128166, 128167, 128168, 128169, 128170, 128171, 128172, 128173, 128174, 128175, 128176, 128177, 128178, 128179, 128180, 128181, 128182, 128183, 128184, 128185, 128186, 128187, 128188, 128189, 128190, 128191, 128192, 128193, 128194, 128195, 128196, 128197, 128198, 128199, 128200, 128201, 128202, 128203, 128204, 128205, 128206, 128207, 128208, 128209, 128210, 128211, 128212, 128213, 128214, 128215, 128216, 128217, 128218, 128219, 128220, 128221, 128222, 128223, 128224, 128225, 128226, 128227, 128228, 128229, 128230, 128231, 128232, 128233, 128234, 128235, 128236, 128237, 128238, 128239, 128240, 128241, 128242, 128243, 128244, 128245, 128246, 128247, 128248, 128249, 128250, 128251, 128252, 128253, 128255, 128256, 128257, 128258, 128259, 128260, 128261, 128262, 128263, 128264, 128265, 128266, 128267, 128268, 128269, 128270, 128271, 128272, 128273, 128274, 128275, 128276, 128277, 128278, 128279, 128280, 128281, 128282, 128283, 128284, 128285, 128286, 128287, 128288, 128289, 128290, 128291, 128292, 128293, 128294, 128295, 128296, 128297, 128298, 128299, 128300, 128301, 128302, 128303, 128304, 128305, 128306, 128307, 128308, 128309, 128310, 128311, 128312, 128313, 128314, 128315, 128316, 128317, 128329, 128330, 128331, 128332, 128333, 128334, 128336, 128337, 128338, 128339, 128340, 128341, 128342, 128343, 128344, 128345, 128346, 128347, 128348, 128349, 128350, 128351, 128352, 128353, 128354, 128355, 128356, 128357, 128358, 128359, 128367, 128368, 128371, 128372, 128373, 128374, 128375, 128376, 128377, 128378, 128391, 128394, 128395, 128396, 128397, 128400, 128405, 128406, 128420, 128421, 128424, 128433, 128434, 128444, 128450, 128451, 128452, 128465, 128466, 128467, 128476, 128477, 128478, 128481, 128483, 128488, 128495, 128499, 128506, 128507, 128508, 128509, 128510, 128511, 128512, 128513, 128514, 128515, 128516, 128517, 128518, 128519, 128520, 128521, 128522, 128523, 128524, 128525, 128526, 128527, 128528, 128529, 128530, 128531, 128532, 128533, 128534, 128535, 128536, 128537, 128538, 128539, 128540, 128541, 128542, 128543, 128544, 128545, 128546, 128547, 128548, 128549, 128550, 128551, 128552, 128553, 128554, 128555, 128556, 128557, 128558, 128559, 128560, 128561, 128562, 128563, 128564, 128565, 128566, 128567, 128568, 128569, 128570, 128571, 128572, 128573, 128574, 128575, 128576, 128577, 128578, 128579, 128580, 128581, 128582, 128583, 128584, 128585, 128586, 128587, 128588, 128589, 128590, 128591, 128640, 128641, 128642, 128643, 128644, 128645, 128646, 128647, 128648, 128649, 128650, 128651, 128652, 128653, 128654, 128655, 128656, 128657, 128658, 128659, 128660, 128661, 128662, 128663, 128664, 128665, 128666, 128667, 128668, 128669, 128670, 128671, 128672, 128673, 128674, 128675, 128676, 128677, 128678, 128679, 128680, 128681, 128682, 128683, 128684, 128685, 128686, 128687, 128688, 128689, 128690, 128691, 128692, 128693, 128694, 128695, 128696, 128697, 128698, 128699, 128700, 128701, 128702, 128703, 128704, 128705, 128706, 128707, 128708, 128709, 128715, 128716, 128717, 128718, 128719, 128720, 128721, 128722, 128725, 128726, 128727, 128733, 128734, 128735, 128736, 128737, 128738, 128739, 128740, 128741, 128745, 128747, 128748, 128752, 128755, 128756, 128757, 128758, 128759, 128760, 128761, 128762, 128763, 128764, 128992, 128993, 128994, 128995, 128996, 128997, 128998, 128999, 129000, 129001, 129002, 129003, 129008, 129292, 129293, 129294, 129295, 129296, 129297, 129298, 129299, 129300, 129301, 129302, 129303, 129304, 129305, 129306, 129307, 129308, 129309, 129310, 129311, 129312, 129313, 129314, 129315, 129316, 129317, 129318, 129319, 129320, 129321, 129322, 129323, 129324, 129325, 129326, 129327, 129328, 129329, 129330, 129331, 129332, 129333, 129334, 129335, 129336, 129337, 129338, 129340, 129341, 129342, 129343, 129344, 129345, 129346, 129347, 129348, 129349, 129351, 129352, 129353, 129354, 129355, 129356, 129357, 129358, 129359, 129360, 129361, 129362, 129363, 129364, 129365, 129366, 129367, 129368, 129369, 129370, 129371, 129372, 129373, 129374, 129375, 129376, 129377, 129378, 129379, 129380, 129381, 129382, 129383, 129384, 129385, 129386, 129387, 129388, 129389, 129390, 129391, 129392, 129393, 129394, 129395, 129396, 129397, 129398, 129399, 129400, 129401, 129402, 129403, 129404, 129405, 129406, 129407, 129408, 129409, 129410, 129411, 129412, 129413, 129414, 129415, 129416, 129417, 129418, 129419, 129420, 129421, 129422, 129423, 129424, 129425, 129426, 129427, 129428, 129429, 129430, 129431, 129432, 129433, 129434, 129435, 129436, 129437, 129438, 129439, 129440, 129441, 129442, 129443, 129444, 129445, 129446, 129447, 129448, 129449, 129450, 129451, 129452, 129453, 129454, 129455, 129456, 129457, 129458, 129459, 129460, 129461, 129462, 129463, 129464, 129465, 129466, 129467, 129468, 129469, 129470, 129471, 129472, 129473, 129474, 129475, 129476, 129477, 129478, 129479, 129480, 129481, 129482, 129483, 129484, 129485, 129486, 129487, 129488, 129489, 129490, 129491, 129492, 129493, 129494, 129495, 129496, 129497, 129498, 129499, 129500, 129501, 129502, 129503, 129504, 129505, 129506, 129507, 129508, 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と怒られる．
また，上記エラーで見つからないと言われたグリフIDを削除してフォントを生成すると成功する．
しかし，図のようにグリフが合成されていない状態で表示される．
ターミナル上の表示幅も壊れてそう．
0️⃣が本来は全角幅だが，半角幅で表示される．絵文字は全角幅で表示する規定があった気がする．(ambiguousだったかも)
たつおレイヤーを重ねる系の絵文字のコードポイントが含まれているとエラーになるっぽい．上記のエラーメッセージで出力されているものはそうだった．