帮助将 python ctypes struct 转换为 64bit

Question

我发现此脚本附加到a thread in the fontforge-users mailing list。 正是我想要的。但是，它似乎只适用于 32 位系统，我真的很想在我的 64 位系统上使用它。

我做了一些阅读，但我不知道应该如何修改这个脚本（大概是 stuct？）以使其在 64 位架构下工作。有人可以帮忙吗？

干杯！

#!/usr/bin/python
# vim:ts=8:sw=4:expandtab:encoding=utf-8
# Export named font from PDF file using fontforge and ctypes

import sys
from ctypes import *

STRING = c_char_p
real = c_longdouble

# We need the `map` attribute of SplineFont, so declear an incomplete struct.
# see: http://sourceforge.net/projects/wqy/files/misc/
# file: fontforge-bindctypes-0.1.tar.bz2
class splinefont(Structure):
    pass
SplineFont = splinefont
splinefont._fields_ = [
    ('fontname', STRING),
    ('fullname', STRING),
    ('familyname', STRING),
    ('weight', STRING),
    ('copyright', STRING),
    ('filename', STRING),
    ('defbasefilename', STRING),
    ('version', STRING),
    ('italicangle', real),
    ('upos', real),
    ('uwidth', real),
    ('ascent', c_int),
    ('descent', c_int),
    ('uniqueid', c_int),
    ('glyphcnt', c_int),
    ('glyphmax', c_int),
    ('glyphs', POINTER(c_void_p)),
    ('changed', c_uint, 1),
    ('changed_since_autosave', c_uint, 1),
    ('changed_since_xuidchanged', c_uint, 1),
    ('display_antialias', c_uint, 1),
    ('display_bbsized', c_uint, 1),
    ('dotlesswarn', c_uint, 1),
    ('onlybitmaps', c_uint, 1),
    ('serifcheck', c_uint, 1),
    ('issans', c_uint, 1),
    ('isserif', c_uint, 1),
    ('hasvmetrics', c_uint, 1),
    ('loading_cid_map', c_uint, 1),
    ('dupnamewarn', c_uint, 1),
    ('encodingchanged', c_uint, 1),
    ('multilayer', c_uint, 1),
    ('strokedfont', c_uint, 1),
    ('new', c_uint, 1),
    ('compacted', c_uint, 1),
    ('backedup', c_uint, 2),
    ('use_typo_metrics', c_uint, 1),
    ('weight_width_slope_only', c_uint, 1),
    ('save_to_dir', c_uint, 1),
    ('head_optimized_for_cleartype', c_uint, 1),
    ('ticked', c_uint, 1),
    ('internal_temp', c_uint, 1),
    ('complained_about_spiros', c_uint, 1),
    ('use_xuid', c_uint, 1),
    ('use_uniqueid', c_uint, 1),
    ('fv', c_void_p),
    ('metrics', c_void_p),
    ('uni_interp', c_int),
    ('for_new_glyphs', c_void_p),
    ('map', c_void_p),
    # ...
]

def main():
    if len(sys.argv) != 3:
        print "Usage: %s doc.pdf fontname" % sys.argv[0]
        sys.exit(2)
    pdfname = sys.argv[1]
    fontname = sys.argv[2]
    fontfile = fontname + '.ttf'

    # ctypes functions
    libc = CDLL("libc.so.6")
    libc.fopen.restype = c_void_p
    libc.fopen.argtype = [c_char_p, c_char_p]

    lib_ff = CDLL('libfontforge.so.1')

    # SplineFont *_SFReadPdfFont(FILE *pdf,char *filename,
    #     char *select_this_font, enum openflags openflags)
    lib_ff._SFReadPdfFont.argtypes = [c_void_p, c_char_p, c_char_p, c_int]
    lib_ff._SFReadPdfFont.restype = POINTER(SplineFont)

    # int GenerateScript(SplineFont *sf, char *filename, char *bitmaptype,
    #     int fmflags, int res, char *subfontdefinition, struct sflist *sfs,
    #     EncMap *map, NameList *rename_to,int layer)
    lib_ff.GenerateScript.argytpes = [POINTER(SplineFont), c_char_p, c_char_p,
            c_int, c_int, c_char_p, c_void_p, c_void_p, c_void_p, c_int]
    lib_ff.GenerateScript.restype = c_int

    # need to somehow initialize libfontforge or it will segfault somewhere.
    lib_ff.doinitFontForgeMain()
    fobj = libc.fopen(pdfname, "rb")
    if not fobj:
        print "%s not found" % pdfname
        sys.exit(1)

    font = lib_ff._SFReadPdfFont(fobj, pdfname, fontname, 0)
    ret = 0
    if bool(font):
        ret = lib_ff.GenerateScript(font, fontfile, None, -1, -1, None, None,
                font.contents.map, None, 1)
    if ret:
        print 'Font export to "%s".' % fontfile
    else:
        print "** Error ** Failed to export font!!"

if __name__ == '__main__':
    main()

Answer 1

问题是 /usr/include/fontforge/config.h 中是否定义了 FONTFORGE_CONFIG_USE_LONGDOUBLE。如果已定义，则代码的定义是正确的。在我的 amd64 linux 安装中，既没有定义 FONTFORGE_CONFIG_USE_LONGDOUBLE 也没有定义 FONTFORGE_CONFIG_USE_DOUBLE，所以我需要更改

real = c_float

有了这个改变，它就可以正常工作了。