add UnicodeEngine (MultiEngineText and axis texters returning MultiEngineText), texte...
[PyX.git] / pyx / font / t1code.py
blobae23ff476be1124065099c9a9fbeecc39533b29e
1 # -*- encoding: utf-8 -*-
4 # Copyright (C) 2005-2006 André Wobst <wobsta@users.sourceforge.net>
6 # This file is part of PyX (http://pyx.sourceforge.net/).
8 # PyX is free software; you can redistribute it and/or modify
9 # it under the terms of the GNU General Public License as published by
10 # the Free Software Foundation; either version 2 of the License, or
11 # (at your option) any later version.
13 # PyX is distributed in the hope that it will be useful,
14 # but WITHOUT ANY WARRANTY; without even the implied warranty of
15 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 # GNU General Public License for more details.
18 # You should have received a copy of the GNU General Public License
19 # along with PyX; if not, write to the Free Software
20 # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
22 import array
24 c1 = 52845
25 c1_16, c1_8 = divmod(c1, 0x100) # to avoid overflow (or conversion to the slow long integers)
26 c2 = 22719
28 def decoder(code, r, n):
29 plain = array.array("B")
30 for x in array.array("B", code):
31 plain.append(x ^ (r >> 8))
32 # r = ((x + r) * c1 + c2) & 0xffff # this might overflow
33 r = ((((x + r) * c1_16) & 0xff) * 0x100 + (x + r) * c1_8 + c2) & 0xffff
34 return plain.tobytes()[n:]
36 def encoder(data, r, random):
37 code = array.array("B")
38 for x in array.array("B", random+data):
39 code.append(x ^ (r>>8))
40 # r = ((code[-1] + r) * c1 + c2) & 0xffff # this might overflow
41 r = ((((code[-1] + r) * c1_16) & 0xff) * 0x100 + (code[-1] + r) * c1_8 + c2) & 0xffff
42 return code.tobytes()