Fonttools unable to read Noto CJK TTC files

[roozbehp]

It seems that ToT fonttools cannot read ToT noto-cjk TTC files.

Here's what I run and what I get:

$ PYTHONPATH=$HOME/src/fonttools/Lib python
Python 2.7.6 (default, Jun 22 2015, 17:58:13) 
[GCC 4.8.2] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> from fontTools import ttLib
>>> ttLib.TTFont('NotoSansSC-Regular.otf')
<fontTools.ttLib.TTFont object at 0x7f06c16a1790>
>>> ttLib.TTFont('NotoSansCJK-Regular.ttc')
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/local/google/home/roozbeh/src/fonttools/Lib/fontTools/ttLib/__init__.py", line 180, in __init__
    self.reader = sfnt.SFNTReader(file, checkChecksums, fontNumber=fontNumber)
  File "/usr/local/google/home/roozbeh/src/fonttools/Lib/fontTools/ttLib/sfnt.py", line 62, in __init__
    raise ttLib.TTLibError("specify a font number between 0 and %d (inclusive)" % (self.numFonts - 1))
fontTools.ttLib.TTLibError: specify a font number between 0 and 7 (inclusive)
>>> ttLib.TTFont('NotoSansCJK-Regular.ttc', 0)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/local/google/home/roozbeh/src/fonttools/Lib/fontTools/ttLib/__init__.py", line 180, in __init__
    self.reader = sfnt.SFNTReader(file, checkChecksums, fontNumber=fontNumber)
  File "/usr/local/google/home/roozbeh/src/fonttools/Lib/fontTools/ttLib/sfnt.py", line 62, in __init__
    raise ttLib.TTLibError("specify a font number between 0 and %d (inclusive)" % (self.numFonts - 1))
fontTools.ttLib.TTLibError: specify a font number between 0 and 7 (inclusive)
>>> ttLib.TTFont('NotoSansCJK-Regular.ttc', 2)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/local/google/home/roozbeh/src/fonttools/Lib/fontTools/ttLib/__init__.py", line 164, in __init__
    file = macUtils.SFNTResourceReader(file, res_name_or_index)
  File "/usr/local/google/home/roozbeh/src/fonttools/Lib/fontTools/ttLib/macUtils.py", line 42, in __init__
    reader = ResourceReader(path)
  File "/usr/local/google/home/roozbeh/src/fonttools/Lib/fontTools/misc/macRes.py", line 32, in __init__
    self._readFile()
  File "/usr/local/google/home/roozbeh/src/fonttools/Lib/fontTools/misc/macRes.py", line 52, in _readFile
    self._readTypeList()
  File "/usr/local/google/home/roozbeh/src/fonttools/Lib/fontTools/misc/macRes.py", line 93, in _readTypeList
    resources = self._readReferenceList(resType, refListOffset, numRes)
  File "/usr/local/google/home/roozbeh/src/fonttools/Lib/fontTools/misc/macRes.py", line 102, in _readReferenceList
    res.decompile(refData, self)
  File "/usr/local/google/home/roozbeh/src/fonttools/Lib/fontTools/misc/macRes.py", line 186, in decompile
    dataLength, = struct.unpack(">L", reader._read(4, absDataOffset))
  File "/usr/local/google/home/roozbeh/src/fonttools/Lib/fontTools/misc/macRes.py", line 67, in _read
    raise ResourceError('Cannot read resource (not enough data)')
fontTools.misc.macRes.ResourceError: Cannot read resource (not enough data)
>>>

fonttools version: 87d1388
noto-cjk version: notofonts/noto-cjk@f36eda0
/cc @dougfelt @kenlunde

[behdad]

Weird. I'll try it out. But to make sure, you're not on a Mac, are you?

[roozbehp]

Linux. Python version on top of output.

[anthrotype]

Thanks for the report, I'll also have a look.
The macRes module is not Mac-only, as we no longer rely on the mac-only Res module, but have our own ResourceReader.

[anthrotype]

@roozbehp is this the "NotoSansCJK-Regular.ttc" file you used?

[anthrotype]

Please have a look at the signature of the TTFont class constructor. The second positional argument is res_name_or_index which is used for reading mac sfnt resources (ttx defaults to the first sftn resource at 0 index). For TTC, you want to use fontNumber keyword argument.

>>> ttLib.TTFont("/Users/cosimolupo/Downloads/NotoSansCJK-Regular.ttc", fontNumber=0)

[anthrotype]

when we merge the DFONT/TTC into the sampe API, we shall deprecate res_name_or_index argument and only use fontNumber. See #228

[behdad]

Please have a look at the signature of the TTFont class constructor. The second positional argument is res_name_or_index which is used for reading mac sfnt resources (ttx defaults to the first sftn resource at 0 index). For TTC, you want to use fontNumber keyword argument.

Roozbeh is NOT setting the res_name_or_index argument, right? In that case we expect this exception:

raise ttLib.TTLibError("specify a font number between 0 and %d (inclusive)" % (self.numFonts - 1))

so if we're getting error from bowels of mac resource stuff, that looks like a regression to me.

[anthrotype]

he is calling it like that

ttLib.TTFont('NotoSansCJK-Regular.ttc', 0)

so he is setting res_name_or_index.

[behdad]

Oh, my bad.

[anthrotype]

as the docstring explains, then res_name_or_index is set to 0 (default), then TTFont will

autodetect whether the file is a flat file or a suitcase. (If it's a suitcase, only the first 'sfnt' resource will be read!)

The TTC font is not a mac resource or data fork font, so the autodetection skips the resource reader, but the ttc reader fails because fontNumber=-1.

When @roozbehp tried with res_name_or_index=2, then the resource reader raises an exception since it does not find a resource map.

[roozbehp]

Sorry for the false alarm. Late night and overconfidence ;)