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"""The base class for complex shapers.
Shaper.py is the top-level interface to shaperlib. This is a lower-level
module implementing common routines used to the individual complex shapers."""
from fontFeatures.shaperLib.Buffer import Buffer, BufferItem
from copy import copy
import unicodedata
from youseedee import ucd_data
from fontFeatures import RoutineReference
def _is_default_ignorable(c):
return (
c in [0x00AD, 0x034F, 0x061C, 0x17B4, 0x17B5, 0xFEFF]
or 0x180B <= c <= 0x180E
or 0x200B <= c <= 0x200F
or 0x202A <= c <= 0x202E
or 0x2060 <= c <= 0x206F
or 0xFE00 <= c <= 0xFE0F
or 0xFFF0 <= c <= 0xFFF8
or 0x1D173 <= c <= 0x1D17A
or 0xE0000 <= c <= 0xE0FFF
)
class BaseShaper:
"""A complex shaper object."""
def __init__(self, plan, font, buf, features=[]):
self.plan = plan
self.font = font
self.buffer = buf
self.features = features
def shape(self):
"""Shape a buffer."""
self.plan.fontfeatures.resolveAllRoutines()
# self.buffer.set_unicode_props()
# self.insert_dotted_circles()
# self.buffer.form_clusters()
# self.buffer.ensure_native_direction()
if not self.buffer.is_all_glyphs:
self.preprocess_text()
# Substitute pre
self.substitute_default()
self.substitute_complex()
# Substitute post
self.delete_default_ignorables()
self.position()
self.postprocess_glyphs()
# self.buffer.propagate_flags()
def preprocess_text(self):
"""Do any processing which needs to happen to character items before shaping."""
pass
def postprocess_glyphs(self):
"""Do any processing which needs to happen to glyph items after shaping."""
pass
def substitute_default(self):
"""Do initial subsitution processing: buffer normalization and mapping."""
self.normalize_unicode_buffer()
self.buffer.map_to_glyphs()
self.plan.msg("Initial glyph mapping", self.buffer)
# Setup masks
# if self.buf.fallback_mark_positioning:
# self.fallback_mark_position_recategorize_marks()
pass
def normalize_unicode_buffer(self):
"""Normalize an OpenType buffer."""
unistring = "".join([chr(item.codepoint) for item in self.buffer.items])
self.buffer.store_unicode(unicodedata.normalize("NFC", unistring))
# Some fix-ups from hb-ot-shape-normalize
for item in self.buffer.items:
if ucd_data(item.codepoint)[
"General_Category"
] == "Zs" and self.font.unicode_map.get(0x20, None):
item.codepoint = 0x20
# Harfbuzz adjusts the width here, in _hb_ot_shape_fallback_spaces
if item.codepoint == 0x2011 and self.font.unicode_map.get(0x2010, None):
item.codepoint = 0x2010
def collect_features(self, shaper):
"""Collect all complex features to be run by this shaper. (Abstract method.)"""
return []
def substitute_complex(self):
"""Run the substitution stage."""
self._run_stage("sub")
def position(self):
"""Run the positioning stage."""
self._run_stage("pos")
self.buffer.clear_mask()
# zero width marks
for i in self.buffer.items:
if i.category[0] == "mark":
i.position.xAdvance = 0
# zero width default ignorables
self.zero_width_default_ignorables()
for i in range(0, len(self.buffer.items)):
self.propagate_attachment_offsets(i)
self.plan.msg("Positioning done", self.buffer)
def propagate_attachment_offsets(self, i):
"""Resolve attachment offsets for item ``i``."""
if not hasattr(self.buffer.items[i], "attach_type"):
return
attach_type = self.buffer.items[i].attach_type
attach_chain = self.buffer.items[i].attach_chain
if not attach_chain:
return
self.buffer.items[i].attach_chain = None
j = i + attach_chain
if j >= len(self.buffer.items):
return
self.propagate_attachment_offsets(j)
if attach_type == "cursive":
pass
# self.buffer.items[i].position.yPlacement = (self.buffer.items[i].position.yPlacement or 0) + (self.buffer.items[j].position.yPlacement or 0) # XXX Horizontal only
else:
self.buffer.items[i].position.xPlacement += (
self.buffer.items[j].position.xPlacement or 0
)
self.buffer.items[i].position.yPlacement += (
self.buffer.items[j].position.yPlacement or 0
)
assert j < i
if self.buffer.direction == "LTR":
for k in range(j, i):
self.buffer.items[i].position.xPlacement -= self.buffer.items[
k
].position.xAdvance
self.buffer.items[i].position.yPlacement -= (
self.buffer.items[k].position.yAdvance or 0
)
else:
for k in range(j + 1, i + 1):
self.buffer.items[i].position.xPlacement += self.buffer.items[
k
].position.xAdvance
self.buffer.items[i].position.yPlacement += (
self.buffer.items[k].position.yAdvance or 0
)
def _run_stage(self, current_stage):
self.plan.msg("Running %s stage" % current_stage)
self.plan.fontfeatures.hoist_languages()
for stage in self.plan.stages:
lookups = []
if isinstance(stage, list): # Features
for f in stage:
if f not in self.plan.fontfeatures.features:
continue
routines = self.plan.fontfeatures.features[f]
routines = [
x.routine if isinstance(x, RoutineReference) else x
for x in routines
]
lookups.extend(
[(routine, f) for routine in self._filter_by_lang(routines)]
)
self.plan.msg("Processing features: %s" % ",".join(stage))
for r, feature in lookups:
self.plan.msg(
"Before %s (%s)" % (r.name, feature), buffer=self.buffer
)
r.apply_to_buffer(
self.buffer,
stage=current_stage,
feature=feature,
namedclasses=self.plan.fontfeatures.namedClasses,
)
self.plan.msg(
"After %s (%s)" % (r.name, feature), buffer=self.buffer
)
else:
# It's a pause. We only support GSUB pauses.
if current_stage == "sub":
stage(current_stage)
def _filter_by_lang(self, routines):
script = self.script_to_opentype.get(self.buffer.script, "DFLT")
s_l = self.plan.fontfeatures.scripts_and_languages
if (
not self.buffer.script
or len(s_l.values()) < 2
and (len(s_l.values()) == 0 or len(list(s_l.values())[0]) < 2)
):
return routines # !
language = self.buffer.language or "dflt"
if script in s_l and (script, language) != ("DFLT", "dflt"):
return [
x for x in routines if x.languages and (script, language) in x.languages
]
else:
return [
x
for x in routines
if not x.languages or ("DFLT", language) in x.languages
]
def delete_default_ignorables(self):
"""Remove all items from the buffer which are ignorable."""
self.buffer.items = [
x
for x in self.buffer.items
if not (x.codepoint) or not _is_default_ignorable(x.codepoint)
]
def zero_width_default_ignorables(self):
"""Set all items from the buffer which are ignorable to zero advance width."""
space = BufferItem.new_unicode(0x20)
space.map_to_glyph(self.buffer.font)
if space.glyph == -1:
return
for ix, item in enumerate(self.buffer.items):
if item.codepoint and _is_default_ignorable(item.codepoint):
item.glyph = space.glyph
item.position.xAdvance = 0
for i in self.buffer.items[ix:]:
if hasattr(i, "syllable_index"):
i.syllable_index += 1
def would_substitute(self, feature, subbuffer_items):
"""Test whether the feature would apply to a list of BufferItem objects."""
if feature not in self.plan.fontfeatures.features:
return False
subbuffer = Buffer(
self.buffer.font,
direction=self.buffer.direction,
script=self.buffer.script,
language=self.buffer.language,
)
subbuffer.clear_mask()
subbuffer.items = [copy(x) for x in subbuffer_items]
subbuffer.clear_mask()
routines = self.plan.fontfeatures.features[feature]
for r in routines:
if isinstance(r, RoutineReference):
r = r.routine
for rule in r.rules:
if rule.stage == "pos":
continue
if any(
[
rule.would_apply_at_position(
subbuffer,
i,
namedclasses=self.plan.fontfeatures.namedClasses,
)
for i in range(len(subbuffer))
]
):
return True
return False
script_to_opentype = {
"Common": "zyyy",
"Inherited": "zinh",
"Unknown": "zzzz",
"Arabic": "arab",
"Armenian": "armn",
"Bengali": "bng2", # Not beng
"Cyrillic": "cyrl",
"Devanagari": "dev2", # Not deva
"Georgian": "geor",
"Greek": "grek",
"Gujarati": "gjr2", # Not gujr
"Gurmukhi": "gur2", # Not guru
"Hangul": "hang",
"Han": "hani",
"Hebrew": "hebr",
"Hiragana": "hira",
"Kannada": "knd2", # Not knda
"Katakana": "kana",
"Lao": "laoo",
"Latin": "latn",
"Malayalam": "mlm2", # Not mlym
"Oriya": "ory2", # Not orya
"Tamil": "tml2", # Not taml
"Telugu": "tel2", # Not telu
"Thai": "thai",
"Tibetan": "tibt",
"Bopomofo": "bopo",
"Braille": "brai",
"Canadian_Syllabics": "cans",
"Cherokee": "cher",
"Ethiopic": "ethi",
"Khmer": "khmr",
"Mongolian": "mong",
"Myanmar": "mym2", # Not mymr
"Ogham": "ogam",
"Runic": "runr",
"Sinhala": "sinh",
"Syriac": "syrc",
"Thaana": "thaa",
"Yi": "yiii",
"Deseret": "dsrt",
"Gothic": "goth",
"Old_Italic": "ital",
"Buhid": "buhd",
"Hanunoo": "hano",
"Tagalog": "tglg",
"Tagbanwa": "tagb",
"Cypriot": "cprt",
"Limbu": "limb",
"Linear_B": "linb",
"Osmanya": "osma",
"Shavian": "shaw",
"Tai_Le": "tale",
"Ugaritic": "ugar",
"Buginese": "bugi",
"Coptic": "copt",
"Glagolitic": "glag",
"Kharoshthi": "khar",
"New_Tai_Lue": "talu",
"Old_Persian": "xpeo",
"Syloti_Nagri": "sylo",
"Tifinagh": "tfng",
"Balinese": "bali",
"Cuneiform": "xsux",
"Nko": "nkoo",
"Phags_Pa": "phag",
"Phoenician": "phnx",
"Carian": "cari",
"Cham": "cham",
"Kayah_Li": "kali",
"Lepcha": "lepc",
"Lycian": "lyci",
"Lydian": "lydi",
"Ol_Chiki": "olck",
"Rejang": "rjng",
"Saurashtra": "saur",
"Sundanese": "sund",
"Vai": "vaii",
"Avestan": "avst",
"Bamum": "bamu",
"Egyptian_Hieroglyphs": "egyp",
"Imperial_Aramaic": "armi",
"Inscriptional_Pahlavi": "phli",
"Inscriptional_Parthian": "prti",
"Javanese": "java",
"Kaithi": "kthi",
"Lisu": "lisu",
"Meetei_Mayek": "mtei",
"Old_South_Arabian": "sarb",
"Old_Turkic": "orkh",
"Samaritan": "samr",
"Tai_Tham": "lana",
"Tai_Viet": "tavt",
"Batak": "batk",
"Brahmi": "brah",
"Mandaic": "mand",
"Chakma": "cakm",
"Meroitic_Cursive": "merc",
"Meroitic_Hieroglyphs": "mero",
"Miao": "plrd",
"Sharada": "shrd",
"Sora_Sompeng": "sora",
"Takri": "takr",
"Bassa_Vah": "bass",
"Caucasian_Albanian": "aghb",
"Duployan": "dupl",
"Elbasan": "elba",
"Grantha": "gran",
"Khojki": "khoj",
"Khudawadi": "sind",
"Linear_A": "lina",
"Mahajani": "mahj",
"Manichaean": "mani",
"Mende_Kikakui": "mend",
"Modi": "modi",
"Mro": "mroo",
"Nabataean": "nbat",
"Old_North_Arabian": "narb",
"Old_Permic": "perm",
"Pahawh_Hmong": "hmng",
"Palmyrene": "palm",
"Pau_Cin_Hau": "pauc",
"Psalter_Pahlavi": "phlp",
"Siddham": "sidd",
"Tirhuta": "tirh",
"Warang_Citi": "wara",
"Ahom": "ahom",
"Anatolian_Hieroglyphs": "hluw",
"Hatran": "hatr",
"Multani": "mult",
"Old_Hungarian": "hung",
"Signwriting": "sgnw",
"Adlam": "adlm",
"Bhaiksuki": "bhks",
"Marchen": "marc",
"Osage": "osge",
"Tangut": "tang",
"Newa": "newa",
"Masaram_Gondi": "gonm",
"Nushu": "nshu",
"Soyombo": "soyo",
"Zanabazar_Square": "zanb",
"Dogra": "dogr",
"Gunjala_Gondi": "gong",
"Hanifi_Rohingya": "rohg",
"Makasar": "maka",
"Medefaidrin": "medf",
"Old_Sogdian": "sogo",
"Sogdian": "sogd",
"Elymaic": "elym",
"Nandinagari": "nand",
"Nyiakeng_Puachue_Hmong": "hmnp",
"Wancho": "wcho",
"Chorasmian": "chrs",
"Dives_Akuru": "diak",
"Khitan_Small_Script": "kits",
"Yezidi": "yezi",
}
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