dvi/vffile.py

   1 # -*- encoding: utf-8 -*-
   2 #
   3 #
   4 # Copyright (C) 2002-2007 Jörg Lehmann <joergl@users.sourceforge.net>
   5 # Copyright (C) 2002-2007 André Wobst <wobsta@users.sourceforge.net>
   6 #
   7 # This file is part of PyX (http://pyx.sourceforge.net/).
   8 #
   9 # PyX is free software; you can redistribute it and/or modify
  10 # it under the terms of the GNU General Public License as published by
  11 # the Free Software Foundation; either version 2 of the License, or
  12 # (at your option) any later version.
  13 #
  14 # PyX is distributed in the hope that it will be useful,
  15 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  16 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17 # GNU General Public License for more details.
  18 #
  19 # You should have received a copy of the GNU General Public License
  20 # along with PyX; if not, write to the Free Software
  21 # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
  22
  23 from pyx import reader
  24
  25 _VF_LONG_CHAR  = 242   # character packet (long version)
  26 _VF_FNTDEF1234 = 243   # font definition
  27 _VF_PRE        = 247   # preamble
  28 _VF_POST       = 248   # postamble
  29 _VF_ID         = 202   # VF id byte
  30
  31 class VFError(Exception): pass
  32
  33 class vffile:
  34
  35     def __init__(self, file, scale, tfmconv, pyxconv, debug=0):
  36         self.scale = scale
  37         self.tfmconv = tfmconv
  38         self.pyxconv = pyxconv
  39         self.debug = debug
  40         self.fonts = {}            # used fonts
  41         self.widths = {}           # widths of defined chars
  42         self.chardefs = {}         # dvi chunks for defined chars
  43
  44         afile = reader.bytesreader(file.read())
  45
  46         cmd = afile.readuchar()
  47         if cmd == _VF_PRE:
  48             if afile.readuchar() != _VF_ID: raise VFError
  49             comment = afile.read(afile.readuchar())
  50             self.cs = afile.readuint32()
  51             self.ds = afile.readuint32()
  52         else:
  53             raise VFError
  54
  55         while True:
  56             cmd = afile.readuchar()
  57             if cmd >= _VF_FNTDEF1234 and cmd < _VF_FNTDEF1234 + 4:
  58                 # font definition
  59                 if cmd == _VF_FNTDEF1234:
  60                     num = afile.readuchar()
  61                 elif cmd == _VF_FNTDEF1234+1:
  62                     num = afile.readuint16()
  63                 elif cmd == _VF_FNTDEF1234+2:
  64                     num = afile.readuint24()
  65                 elif cmd == _VF_FNTDEF1234+3:
  66                     num = afile.readint32()
  67                 c = afile.readint32()
  68                 s = afile.readint32()     # relative scaling used for font (fix_word)
  69                 d = afile.readint32()     # design size of font
  70                 fontname = afile.read(afile.readuchar() + afile.readuchar()).decode("ascii")
  71
  72                 # rescaled size of font: s is relative to the scaling
  73                 # of the virtual font itself.  Note that realscale has
  74                 # to be a fix_word (like s)
  75                 # XXX: check rounding
  76                 reals = int(round(self.scale * (16*self.ds/16777216) * s))
  77
  78                 # print ("defining font %s -- VF scale: %g, VF design size: %d, relative font size: %d => real size: %d" %
  79                 #        (fontname, self.scale, self.ds, s, reals)
  80                 #        )
  81
  82                 # XXX allow for virtual fonts here too
  83                 from . import texfont
  84                 self.fonts[num] =  texfont.TeXfont(fontname, c, reals, d, self.tfmconv, self.pyxconv, self.debug > 1)
  85             elif cmd == _VF_LONG_CHAR:
  86                 # character packet (long form)
  87                 pl = afile.readuint32()   # packet length
  88                 cc = afile.readuint32()   # char code (assumed unsigned, but anyhow only 0 <= cc < 255 is actually used)
  89                 tfm = afile.readuint24()  # character width
  90                 dvi = afile.read(pl)      # dvi code of character
  91                 self.widths[cc] = tfm
  92                 self.chardefs[cc] = dvi
  93             elif cmd < _VF_LONG_CHAR:
  94                 # character packet (short form)
  95                 cc = afile.readuchar()    # char code
  96                 tfm = afile.readuint24()  # character width
  97                 dvi = afile.read(cmd)
  98                 self.widths[cc] = tfm
  99                 self.chardefs[cc] = dvi
 100             elif cmd == _VF_POST:
 101                 break
 102             else:
 103                 raise VFError
 104
 105         afile.close()
 106
 107     def getfonts(self):
 108         return self.fonts
 109
 110     def getchar(self, cc):
 111         return self.chardefs[cc]
 112