[cffLib] Move desubroutinize code to new cffLib.transforms module

This commit is contained in:
Behdad Esfahbod 2024-05-21 12:34:28 -07:00
parent 65cc8bfb3c
commit a851d02519
2 changed files with 118 additions and 115 deletions

View File

@ -45,93 +45,6 @@ maxStackLimit = 513
# maxstack operator has been deprecated. max stack is now always 513.
class StopHintCountEvent(Exception):
pass
class _DesubroutinizingT2Decompiler(psCharStrings.SimpleT2Decompiler):
stop_hintcount_ops = (
"op_hintmask",
"op_cntrmask",
"op_rmoveto",
"op_hmoveto",
"op_vmoveto",
)
def __init__(self, localSubrs, globalSubrs, private=None):
psCharStrings.SimpleT2Decompiler.__init__(
self, localSubrs, globalSubrs, private
)
def execute(self, charString):
self.need_hintcount = True # until proven otherwise
for op_name in self.stop_hintcount_ops:
setattr(self, op_name, self.stop_hint_count)
if hasattr(charString, "_desubroutinized"):
# If a charstring has already been desubroutinized, we will still
# need to execute it if we need to count hints in order to
# compute the byte length for mask arguments, and haven't finished
# counting hints pairs.
if self.need_hintcount and self.callingStack:
try:
psCharStrings.SimpleT2Decompiler.execute(self, charString)
except StopHintCountEvent:
del self.callingStack[-1]
return
charString._patches = []
psCharStrings.SimpleT2Decompiler.execute(self, charString)
desubroutinized = charString.program[:]
for idx, expansion in reversed(charString._patches):
assert idx >= 2
assert desubroutinized[idx - 1] in [
"callsubr",
"callgsubr",
], desubroutinized[idx - 1]
assert type(desubroutinized[idx - 2]) == int
if expansion[-1] == "return":
expansion = expansion[:-1]
desubroutinized[idx - 2 : idx] = expansion
if not self.private.in_cff2:
if "endchar" in desubroutinized:
# Cut off after first endchar
desubroutinized = desubroutinized[
: desubroutinized.index("endchar") + 1
]
charString._desubroutinized = desubroutinized
del charString._patches
def op_callsubr(self, index):
subr = self.localSubrs[self.operandStack[-1] + self.localBias]
psCharStrings.SimpleT2Decompiler.op_callsubr(self, index)
self.processSubr(index, subr)
def op_callgsubr(self, index):
subr = self.globalSubrs[self.operandStack[-1] + self.globalBias]
psCharStrings.SimpleT2Decompiler.op_callgsubr(self, index)
self.processSubr(index, subr)
def stop_hint_count(self, *args):
self.need_hintcount = False
for op_name in self.stop_hintcount_ops:
setattr(self, op_name, None)
cs = self.callingStack[-1]
if hasattr(cs, "_desubroutinized"):
raise StopHintCountEvent()
def op_hintmask(self, index):
psCharStrings.SimpleT2Decompiler.op_hintmask(self, index)
if self.need_hintcount:
self.stop_hint_count()
def processSubr(self, index, subr):
cs = self.callingStack[-1]
if not hasattr(cs, "_desubroutinized"):
cs._patches.append((index, subr._desubroutinized))
class CFFFontSet(object):
"""A CFF font "file" can contain more than one font, although this is
extremely rare (and not allowed within OpenType fonts).
@ -396,34 +309,9 @@ class CFFFontSet(object):
_convertCFF2ToCFF(self, otFont)
def desubroutinize(self):
for fontName in self.fontNames:
font = self[fontName]
cs = font.CharStrings
for c in cs.values():
c.decompile()
subrs = getattr(c.private, "Subrs", [])
decompiler = _DesubroutinizingT2Decompiler(
subrs, c.globalSubrs, c.private
)
decompiler.execute(c)
c.program = c._desubroutinized
del c._desubroutinized
# Delete all the local subrs
if hasattr(font, "FDArray"):
for fd in font.FDArray:
pd = fd.Private
if hasattr(pd, "Subrs"):
del pd.Subrs
if "Subrs" in pd.rawDict:
del pd.rawDict["Subrs"]
else:
pd = font.Private
if hasattr(pd, "Subrs"):
del pd.Subrs
if "Subrs" in pd.rawDict:
del pd.rawDict["Subrs"]
# as well as the global subrs
self.GlobalSubrs.clear()
from .transforms import desubroutinize
desubroutinize(self)
class CFFWriter(object):

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@ -0,0 +1,115 @@
from fontTools.misc.psCharStrings import SimpleT2Decompiler
class StopHintCountEvent(Exception):
pass
class _DesubroutinizingT2Decompiler(SimpleT2Decompiler):
stop_hintcount_ops = (
"op_hintmask",
"op_cntrmask",
"op_rmoveto",
"op_hmoveto",
"op_vmoveto",
)
def __init__(self, localSubrs, globalSubrs, private=None):
SimpleT2Decompiler.__init__(self, localSubrs, globalSubrs, private)
def execute(self, charString):
self.need_hintcount = True # until proven otherwise
for op_name in self.stop_hintcount_ops:
setattr(self, op_name, self.stop_hint_count)
if hasattr(charString, "_desubroutinized"):
# If a charstring has already been desubroutinized, we will still
# need to execute it if we need to count hints in order to
# compute the byte length for mask arguments, and haven't finished
# counting hints pairs.
if self.need_hintcount and self.callingStack:
try:
SimpleT2Decompiler.execute(self, charString)
except StopHintCountEvent:
del self.callingStack[-1]
return
charString._patches = []
SimpleT2Decompiler.execute(self, charString)
desubroutinized = charString.program[:]
for idx, expansion in reversed(charString._patches):
assert idx >= 2
assert desubroutinized[idx - 1] in [
"callsubr",
"callgsubr",
], desubroutinized[idx - 1]
assert type(desubroutinized[idx - 2]) == int
if expansion[-1] == "return":
expansion = expansion[:-1]
desubroutinized[idx - 2 : idx] = expansion
if not self.private.in_cff2:
if "endchar" in desubroutinized:
# Cut off after first endchar
desubroutinized = desubroutinized[
: desubroutinized.index("endchar") + 1
]
charString._desubroutinized = desubroutinized
del charString._patches
def op_callsubr(self, index):
subr = self.localSubrs[self.operandStack[-1] + self.localBias]
SimpleT2Decompiler.op_callsubr(self, index)
self.processSubr(index, subr)
def op_callgsubr(self, index):
subr = self.globalSubrs[self.operandStack[-1] + self.globalBias]
SimpleT2Decompiler.op_callgsubr(self, index)
self.processSubr(index, subr)
def stop_hint_count(self, *args):
self.need_hintcount = False
for op_name in self.stop_hintcount_ops:
setattr(self, op_name, None)
cs = self.callingStack[-1]
if hasattr(cs, "_desubroutinized"):
raise StopHintCountEvent()
def op_hintmask(self, index):
SimpleT2Decompiler.op_hintmask(self, index)
if self.need_hintcount:
self.stop_hint_count()
def processSubr(self, index, subr):
cs = self.callingStack[-1]
if not hasattr(cs, "_desubroutinized"):
cs._patches.append((index, subr._desubroutinized))
def desubroutinize(cff):
for fontName in cff.fontNames:
font = cff[fontName]
cs = font.CharStrings
for c in cs.values():
c.decompile()
subrs = getattr(c.private, "Subrs", [])
decompiler = _DesubroutinizingT2Decompiler(subrs, c.globalSubrs, c.private)
decompiler.execute(c)
c.program = c._desubroutinized
del c._desubroutinized
# Delete all the local subrs
if hasattr(font, "FDArray"):
for fd in font.FDArray:
pd = fd.Private
if hasattr(pd, "Subrs"):
del pd.Subrs
if "Subrs" in pd.rawDict:
del pd.rawDict["Subrs"]
else:
pd = font.Private
if hasattr(pd, "Subrs"):
del pd.Subrs
if "Subrs" in pd.rawDict:
del pd.rawDict["Subrs"]
# as well as the global subrs
cff.GlobalSubrs.clear()