1from fontTools.misc import sstruct 2from fontTools.misc.fixedTools import floatToFixedToStr, strToFixedToFloat 3from fontTools.misc.textTools import safeEval, num2binary, binary2num 4from fontTools.misc.timeTools import ( 5 timestampFromString, 6 timestampToString, 7 timestampNow, 8) 9from fontTools.misc.timeTools import epoch_diff as mac_epoch_diff # For backward compat 10from fontTools.misc.arrayTools import intRect, unionRect 11from . import DefaultTable 12import logging 13 14 15log = logging.getLogger(__name__) 16 17headFormat = """ 18 > # big endian 19 tableVersion: 16.16F 20 fontRevision: 16.16F 21 checkSumAdjustment: I 22 magicNumber: I 23 flags: H 24 unitsPerEm: H 25 created: Q 26 modified: Q 27 xMin: h 28 yMin: h 29 xMax: h 30 yMax: h 31 macStyle: H 32 lowestRecPPEM: H 33 fontDirectionHint: h 34 indexToLocFormat: h 35 glyphDataFormat: h 36""" 37 38 39class table__h_e_a_d(DefaultTable.DefaultTable): 40 dependencies = ["maxp", "loca", "CFF ", "CFF2"] 41 42 def decompile(self, data, ttFont): 43 dummy, rest = sstruct.unpack2(headFormat, data, self) 44 if rest: 45 # this is quite illegal, but there seem to be fonts out there that do this 46 log.warning("extra bytes at the end of 'head' table") 47 assert rest == b"\0\0" 48 49 # For timestamp fields, ignore the top four bytes. Some fonts have 50 # bogus values there. Since till 2038 those bytes only can be zero, 51 # ignore them. 52 # 53 # https://github.com/fonttools/fonttools/issues/99#issuecomment-66776810 54 for stamp in "created", "modified": 55 value = getattr(self, stamp) 56 if value > 0xFFFFFFFF: 57 log.warning("'%s' timestamp out of range; ignoring top bytes", stamp) 58 value &= 0xFFFFFFFF 59 setattr(self, stamp, value) 60 if value < 0x7C259DC0: # January 1, 1970 00:00:00 61 log.warning( 62 "'%s' timestamp seems very low; regarding as unix timestamp", stamp 63 ) 64 value += 0x7C259DC0 65 setattr(self, stamp, value) 66 67 def compile(self, ttFont): 68 if ttFont.recalcBBoxes: 69 # For TT-flavored fonts, xMin, yMin, xMax and yMax are set in table__m_a_x_p.recalc(). 70 if "CFF " in ttFont: 71 topDict = ttFont["CFF "].cff.topDictIndex[0] 72 self.xMin, self.yMin, self.xMax, self.yMax = intRect(topDict.FontBBox) 73 elif "CFF2" in ttFont: 74 topDict = ttFont["CFF2"].cff.topDictIndex[0] 75 charStrings = topDict.CharStrings 76 fontBBox = None 77 for charString in charStrings.values(): 78 bounds = charString.calcBounds(charStrings) 79 if bounds is not None: 80 if fontBBox is not None: 81 fontBBox = unionRect(fontBBox, bounds) 82 else: 83 fontBBox = bounds 84 if fontBBox is not None: 85 self.xMin, self.yMin, self.xMax, self.yMax = intRect(fontBBox) 86 if ttFont.recalcTimestamp: 87 self.modified = timestampNow() 88 data = sstruct.pack(headFormat, self) 89 return data 90 91 def toXML(self, writer, ttFont): 92 writer.comment("Most of this table will be recalculated by the compiler") 93 writer.newline() 94 _, names, fixes = sstruct.getformat(headFormat) 95 for name in names: 96 value = getattr(self, name) 97 if name in fixes: 98 value = floatToFixedToStr(value, precisionBits=fixes[name]) 99 elif name in ("created", "modified"): 100 value = timestampToString(value) 101 elif name in ("magicNumber", "checkSumAdjustment"): 102 if value < 0: 103 value = value + 0x100000000 104 value = hex(value) 105 if value[-1:] == "L": 106 value = value[:-1] 107 elif name in ("macStyle", "flags"): 108 value = num2binary(value, 16) 109 writer.simpletag(name, value=value) 110 writer.newline() 111 112 def fromXML(self, name, attrs, content, ttFont): 113 value = attrs["value"] 114 fixes = sstruct.getformat(headFormat)[2] 115 if name in fixes: 116 value = strToFixedToFloat(value, precisionBits=fixes[name]) 117 elif name in ("created", "modified"): 118 value = timestampFromString(value) 119 elif name in ("macStyle", "flags"): 120 value = binary2num(value) 121 else: 122 value = safeEval(value) 123 setattr(self, name, value) 124