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, canvas, 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, lly, urx, ury)"""
  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, lly, urx, ury) = map(int, bbmatch.groups())
  87             return bbox._bbox(llx, lly, urx, ury)
  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                  showbbox = 0,
 103                  translatebbox = 1,
 104                  bbox = None):
 105         """inserts epsfile
 106
 107         inserts EPS file named filename at position (x,y).  If clip is
 108         set, the result gets clipped to the bbox of the EPS file. If
 109         translatebbox is not set, the EPS graphics is not translated to
 110         the corresponding origin. With showbb set, the bbox is drawn.
 111         If bbox is specified, it overrides the bounding box in the epsfile
 112         itself.
 113
 114         """
 115
 116         self._x = unit.topt(x)
 117         self._y = unit.topt(y)
 118         self.filename = filename
 119         self.mybbox = bbox or _readbbox(self.filename)
 120
 121         # determine scaling in x and y direction
 122         self.scalex = self.scaley = scale
 123
 124         if width is not None or height is not None:
 125             if scale is not None:
 126                 raise ValueError("cannot set both width and/or height and scale simultaneously")
 127             if height is not None:
 128                 self.scaley = unit.topt(height)/(self.mybbox.ury-self.mybbox.lly)
 129             if width is not None:
 130                 self.scalex = unit.topt(width)/(self.mybbox.urx-self.mybbox.llx)
 131
 132             if self.scalex is None:
 133                 self.scalex = self.scaley
 134             if self.scaley is None:
 135                 self.scaley = self.scalex
 136
 137         # set the actual width and height of the eps file (after a
 138         # possible scaling)
 139         self._width  = (self.mybbox.urx-self.mybbox.llx)
 140         if self.scalex:
 141             self._width *= self.scalex
 142
 143         self._height  = (self.mybbox.ury-self.mybbox.lly)
 144         if self.scaley:
 145             self._height *= self.scaley
 146
 147         # take alignment into account
 148         self.align       = align
 149         if self.align[0]=="b":
 150             pass
 151         elif self.align[0]=="c":
 152             self._y -= self._height/2.0
 153         elif self.align[0]=="t":
 154             self._y -= self._height
 155         else:
 156             raise ValueError("vertical alignment can only be b (bottom), c (center), or t (top)")
 157
 158         if self.align[1]=="l":
 159             pass
 160         elif self.align[1]=="c":
 161             self._x -= self._width/2.0
 162         elif self.align[1]=="r":
 163             self._x -= self._width
 164         else:
 165             raise ValueError("horizontal alignment can only be l (left), c (center), or r (right)")
 166
 167         self.clip = clip
 168         self.translatebbox = translatebbox
 169         self.showbbox = showbbox
 170
 171         self.trafo = trafo.translate_pt(self._x, self._y)
 172
 173         if self.scalex is not None:
 174             self.trafo = self.trafo * trafo.scale_pt(self.scalex, self.scaley)
 175
 176         if translatebbox:
 177             self.trafo = self.trafo * trafo.translate_pt(-self.mybbox.llx, -self.mybbox.lly)
 178
 179     def bbox(self):
 180         return self.mybbox.transformed(self.trafo)
 181
 182     def prolog(self):
 183         return [_BeginEPSF, _EndEPSF]
 184
 185     def outputPS(self, file):
 186         try:
 187             epsfile=open(self.filename,"r")
 188         except:
 189             raise IOError, "cannot open EPS file '%s'" % self.filename
 190
 191         file.write("BeginEPSF\n")
 192
 193         bbrect = self.mybbox.rect().transformed(self.trafo)
 194
 195         if self.showbbox:
 196             file.write("newpath\n")
 197             bbrect.outputPS(file)
 198             file.write("stroke\n")
 199
 200         if self.clip:
 201             file.write("newpath\n")
 202             bbrect.outputPS(file)
 203             file.write("clip\n")
 204
 205         self.trafo.outputPS(file)
 206
 207         file.write("%%%%BeginDocument: %s\n" % self.filename)
 208         file.write(epsfile.read())
 209         file.write("%%EndDocument\n")
 210         file.write("EndEPSF\n")