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 timestampFromString, timestampToString, timestampNow
5from fontTools.misc.timeTools import epoch_diff as mac_epoch_diff # For backward compat
6from fontTools.misc.arrayTools import intRect, unionRect
7from . import DefaultTable
8import logging
9
10
11log = logging.getLogger(__name__)
12
13headFormat = """
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
34class table__h_e_a_d(DefaultTable.DefaultTable):
35
36	dependencies = ['maxp', 'loca', 'CFF ', 'CFF2']
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 == b"\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 = intRect(topDict.FontBBox)
67			elif 'CFF2' in ttFont:
68				topDict = ttFont['CFF2'].cff.topDictIndex[0]
69				charStrings = topDict.CharStrings
70				fontBBox = None
71				for charString in charStrings.values():
72					bounds = charString.calcBounds(charStrings)
73					if bounds is not None:
74						if fontBBox is not None:
75							fontBBox = unionRect(fontBBox, bounds)
76						else:
77							fontBBox = bounds
78				if fontBBox is not None:
79					self.xMin, self.yMin, self.xMax, self.yMax = intRect(fontBBox)
80		if ttFont.recalcTimestamp:
81			self.modified = timestampNow()
82		data = sstruct.pack(headFormat, self)
83		return data
84
85	def toXML(self, writer, ttFont):
86		writer.comment("Most of this table will be recalculated by the compiler")
87		writer.newline()
88		_, names, fixes = sstruct.getformat(headFormat)
89		for name in names:
90			value = getattr(self, name)
91			if name in fixes:
92				value = floatToFixedToStr(value, precisionBits=fixes[name])
93			elif name in ("created", "modified"):
94				value = timestampToString(value)
95			elif name in ("magicNumber", "checkSumAdjustment"):
96				if value < 0:
97					value = value + 0x100000000
98				value = hex(value)
99				if value[-1:] == "L":
100					value = value[:-1]
101			elif name in ("macStyle", "flags"):
102				value = num2binary(value, 16)
103			writer.simpletag(name, value=value)
104			writer.newline()
105
106	def fromXML(self, name, attrs, content, ttFont):
107		value = attrs["value"]
108		fixes = sstruct.getformat(headFormat)[2]
109		if name in fixes:
110			value = strToFixedToFloat(value, precisionBits=fixes[name])
111		elif name in ("created", "modified"):
112			value = timestampFromString(value)
113		elif name in ("macStyle", "flags"):
114			value = binary2num(value)
115		else:
116			value = safeEval(value)
117		setattr(self, name, value)
118