pyx/epsfile.py

   1 #!/usr/bin/env python
   2 # -*- coding: ISO-8859-1 -*-
   3 #
   4 #
   5 # Copyright (C) 2002-2004 Jörg Lehmann <joergl@users.sourceforge.net>
   6 # Copyright (C) 2002-2004 André Wobst <wobsta@users.sourceforge.net>
   7 #
   8 # This file is part of PyX (http://pyx.sourceforge.net/).
   9 #
  10 # PyX is free software; you can redistribute it and/or modify
  11 # it under the terms of the GNU General Public License as published by
  12 # the Free Software Foundation; either version 2 of the License, or
  13 # (at your option) any later version.
  14 #
  15 # PyX is distributed in the hope that it will be useful,
  16 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  17 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18 # GNU General Public License for more details.
  19 #
  20 # You should have received a copy of the GNU General Public License
  21 # along with PyX; if not, write to the Free Software
  22 # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  23
  24 import re
  25 import base, bbox, prolog, unit, trafo
  26
  27 # PostScript-procedure definitions (cf. 5002.EPSF_Spec_v3.0.pdf)
  28 # with important correction in EndEPSF:
  29 #   end operator is missing in the spec!
  30
  31 _BeginEPSF = prolog.definition("BeginEPSF", """{
  32   /b4_Inc_state save def
  33   /dict_count countdictstack def
  34   /op_count count 1 sub def
  35   userdict begin
  36   /showpage { } def
  37   0 setgray 0 setlinecap
  38   1 setlinewidth 0 setlinejoin
  39   10 setmiterlimit [ ] 0 setdash newpath
  40   /languagelevel where
  41   {pop languagelevel
  42   1 ne
  43     {false setstrokeadjust false setoverprint
  44     } if
  45   } if
  46 } bind""")
  47
  48 _EndEPSF = prolog.definition("EndEPSF", """{
  49   end
  50   count op_count sub {pop} repeat
  51   countdictstack dict_count sub {end} repeat
  52   b4_Inc_state restore
  53 } bind""")
  54
  55 def _readbbox(filename):
  56     """returns bounding box of EPS file filename as 4-tuple (llx_pt, lly_pt, urx_pt, ury_pt)"""
  57
  58     try:
  59         file = open(filename, "r")
  60     except:
  61         raise IOError, "cannot open EPS file '%s'" % filename
  62
  63     bbpattern = re.compile( r"""^%%BoundingBox:\s+([+-]?\d+)
  64                                              \s+([+-]?\d+)
  65                                              \s+([+-]?\d+)
  66                                              \s+([+-]?\d+)\s*$""" , re.VERBOSE)
  67
  68     try:
  69         readlinesfunc = file.xreadlines
  70     except: # workaround for Python 2.0
  71         readlinesfunc = file.readlines
  72     for line in readlinesfunc():
  73
  74         if line=="%%EndComments\n":
  75             # XXX: BoundingBox-Deklaration kann auch an Ende von Datei
  76             #      verschoben worden sein...
  77             #      ...but evaluation of such a bbox directive requires
  78             #      a parsing of the DSC!
  79             raise IOError, \
  80                   "bounding box not found in header of EPS file '%s'" % \
  81                   filename
  82
  83         bbmatch = bbpattern.match(line)
  84         if bbmatch is not None:
  85             # conversion strings->int
  86             (llx_pt, lly_pt, urx_pt, ury_pt) = map(int, bbmatch.groups())
  87             return bbox.bbox_pt(llx_pt, lly_pt, urx_pt, ury_pt)
  88     else:
  89         raise IOError, \
  90               "bounding box not found in EPS file '%s'" % filename
  91
  92
  93 class epsfile(base.PSCmd):
  94
  95     """class for epsfiles"""
  96
  97     def __init__(self,
  98                  x, y, filename,
  99                  width=None, height=None, scale=None,
 100                  align="bl",
 101                  clip=1,
 102                  translatebbox = 1,
 103                  bbox = None):
 104         """inserts epsfile
 105
 106         inserts EPS file named filename at position (x,y).  If clip is
 107         set, the result gets clipped to the bbox of the EPS file. If
 108         translatebbox is not set, the EPS graphics is not translated to
 109         the corresponding origin. If bbox is not None, it overrides
 110         the bounding box in the epsfile itself.
 111
 112         """
 113
 114         self._x = unit.topt(x)
 115         self._y = unit.topt(y)
 116         self.filename = filename
 117         self.mybbox = bbox or _readbbox(self.filename)
 118
 119         # determine scaling in x and y direction
 120         self.scalex = self.scaley = scale
 121
 122         if width is not None or height is not None:
 123             if scale is not None:
 124                 raise ValueError("cannot set both width and/or height and scale simultaneously")
 125             if height is not None:
 126                 self.scaley = unit.topt(height)/(self.mybbox.ury_pt-self.mybbox.lly_pt)
 127             if width is not None:
 128                 self.scalex = unit.topt(width)/(self.mybbox.urx_pt-self.mybbox.llx_pt)
 129
 130             if self.scalex is None:
 131                 self.scalex = self.scaley
 132             if self.scaley is None:
 133                 self.scaley = self.scalex
 134
 135         # set the actual width and height of the eps file (after a
 136         # possible scaling)
 137         self._width  = self.mybbox.urx_pt-self.mybbox.llx_pt
 138         if self.scalex:
 139             self._width *= self.scalex
 140
 141         self._height = self.mybbox.ury_pt-self.mybbox.lly_pt
 142         if self.scaley:
 143             self._height *= self.scaley
 144
 145         # take alignment into account
 146         self.align       = align
 147         if self.align[0]=="b":
 148             pass
 149         elif self.align[0]=="c":
 150             self._y -= self._height/2.0
 151         elif self.align[0]=="t":
 152             self._y -= self._height
 153         else:
 154             raise ValueError("vertical alignment can only be b (bottom), c (center), or t (top)")
 155
 156         if self.align[1]=="l":
 157             pass
 158         elif self.align[1]=="c":
 159             self._x -= self._width/2.0
 160         elif self.align[1]=="r":
 161             self._x -= self._width
 162         else:
 163             raise ValueError("horizontal alignment can only be l (left), c (center), or r (right)")
 164
 165         self.clip = clip
 166         self.translatebbox = translatebbox
 167
 168         self.trafo = trafo.translate_pt(self._x, self._y)
 169
 170         if self.scalex is not None:
 171             self.trafo = self.trafo * trafo.scale_pt(self.scalex, self.scaley)
 172
 173         if translatebbox:
 174             self.trafo = self.trafo * trafo.translate_pt(-self.mybbox.llx_pt, -self.mybbox.lly_pt)
 175
 176     def bbox(self):
 177         return self.mybbox.transformed(self.trafo)
 178
 179     def prolog(self):
 180         return [_BeginEPSF, _EndEPSF]
 181
 182     def outputPS(self, file):
 183         try:
 184             epsfile=open(self.filename,"r")
 185         except:
 186             raise IOError, "cannot open EPS file '%s'" % self.filename
 187
 188         file.write("BeginEPSF\n")
 189
 190         bbrect = self.mybbox.rect().transformed(self.trafo)
 191
 192         if self.clip:
 193             file.write("newpath\n")
 194             bbrect.outputPS(file)
 195             file.write("clip\n")
 196
 197         self.trafo.outputPS(file)
 198
 199         file.write("%%%%BeginDocument: %s\n" % self.filename)
 200         file.write(epsfile.read())
 201         file.write("%%EndDocument\n")
 202         file.write("EndEPSF\n")