1 from __future__ import print_function, division, absolute_import 2 from fontTools.misc.py23 import * 3 from fontTools.misc import sstruct 4 from fontTools.misc.textTools import safeEval, num2binary, binary2num 5 from fontTools.misc.timeTools import timestampFromString, timestampToString, timestampNow 6 from fontTools.misc.timeTools import epoch_diff as mac_epoch_diff # For backward compat 7 from . import DefaultTable 8 import logging 9 10 11 log = logging.getLogger(__name__) 12 13 headFormat = """ 14 > # big endian 15 tableVersion: 16.16F 16 fontRevision: 16.16F 17 checkSumAdjustment: I 18 magicNumber: I 19 flags: H 20 unitsPerEm: H 21 created: Q 22 modified: Q 23 xMin: h 24 yMin: h 25 xMax: h 26 yMax: h 27 macStyle: H 28 lowestRecPPEM: H 29 fontDirectionHint: h 30 indexToLocFormat: h 31 glyphDataFormat: h 32 """ 33 34 class table__h_e_a_d(DefaultTable.DefaultTable): 35 36 dependencies = ['maxp', 'loca', 'CFF '] 37 38 def decompile(self, data, ttFont): 39 dummy, rest = sstruct.unpack2(headFormat, data, self) 40 if rest: 41 # this is quite illegal, but there seem to be fonts out there that do this 42 log.warning("extra bytes at the end of 'head' table") 43 assert rest == "\0\0" 44 45 # For timestamp fields, ignore the top four bytes. Some fonts have 46 # bogus values there. Since till 2038 those bytes only can be zero, 47 # ignore them. 48 # 49 # https://github.com/fonttools/fonttools/issues/99#issuecomment-66776810 50 for stamp in 'created', 'modified': 51 value = getattr(self, stamp) 52 if value > 0xFFFFFFFF: 53 log.warning("'%s' timestamp out of range; ignoring top bytes", stamp) 54 value &= 0xFFFFFFFF 55 setattr(self, stamp, value) 56 if value < 0x7C259DC0: # January 1, 1970 00:00:00 57 log.warning("'%s' timestamp seems very low; regarding as unix timestamp", stamp) 58 value += 0x7C259DC0 59 setattr(self, stamp, value) 60 61 def compile(self, ttFont): 62 if ttFont.recalcBBoxes: 63 # For TT-flavored fonts, xMin, yMin, xMax and yMax are set in table__m_a_x_p.recalc(). 64 if 'CFF ' in ttFont: 65 topDict = ttFont['CFF '].cff.topDictIndex[0] 66 self.xMin, self.yMin, self.xMax, self.yMax = topDict.FontBBox 67 if ttFont.recalcTimestamp: 68 self.modified = timestampNow() 69 data = sstruct.pack(headFormat, self) 70 return data 71 72 def toXML(self, writer, ttFont): 73 writer.comment("Most of this table will be recalculated by the compiler") 74 writer.newline() 75 formatstring, names, fixes = sstruct.getformat(headFormat) 76 for name in names: 77 value = getattr(self, name) 78 if name in ("created", "modified"): 79 value = timestampToString(value) 80 if name in ("magicNumber", "checkSumAdjustment"): 81 if value < 0: 82 value = value + 0x100000000 83 value = hex(value) 84 if value[-1:] == "L": 85 value = value[:-1] 86 elif name in ("macStyle", "flags"): 87 value = num2binary(value, 16) 88 writer.simpletag(name, value=value) 89 writer.newline() 90 91 def fromXML(self, name, attrs, content, ttFont): 92 value = attrs["value"] 93 if name in ("created", "modified"): 94 value = timestampFromString(value) 95 elif name in ("macStyle", "flags"): 96 value = binary2num(value) 97 else: 98 value = safeEval(value) 99 setattr(self, name, value) 100
