pyx/epsfile.py

   1 #!/usr/bin/env python
   2 #
   3 #
   4 # Copyright (C) 2002 Jörg Lehmann <joergl@users.sourceforge.net>
   5 # Copyright (C) 2002 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  22
  23 import re
  24 import base, bbox, canvas, unit, trafo
  25
  26 # PostScript-procedure definitions (cf. 5002.EPSF_Spec_v3.0.pdf)
  27 # with important correction in EndEPSF:
  28 #   end operator is missing in the spec!
  29
  30 _BeginEPSF = canvas.definition("BeginEPSF", """{
  31   /b4_Inc_state save def
  32   /dict_count countdictstack def
  33   /op_count count 1 sub def
  34   userdict begin
  35   /showpage { } def
  36   0 setgray 0 setlinecap
  37   1 setlinewidth 0 setlinejoin
  38   10 setmiterlimit [ ] 0 setdash newpath
  39   /languagelevel where
  40   {pop languagelevel
  41   1 ne
  42     {false setstrokeadjust false setoverprint
  43     } if
  44   } if
  45 } bind""")
  46
  47 _EndEPSF = canvas.definition("EndEPSF", """{
  48   end
  49   count op_count sub {pop} repeat
  50   countdictstack dict_count sub {end} repeat
  51   b4_Inc_state restore
  52 } bind""")
  53
  54 def _readbbox(filename):
  55     """returns bounding box of EPS file filename as 4-tuple (llx, lly, urx, ury)"""
  56
  57     try:
  58         file = open(filename, "r")
  59     except:
  60         raise IOError, "cannot open EPS file '%s'" % filename
  61
  62     bbpattern = re.compile( r"""^%%BoundingBox:\s+([+-]?\d+)
  63                                              \s+([+-]?\d+)
  64                                              \s+([+-]?\d+)
  65                                              \s+([+-]?\d+)\s*$""" , re.VERBOSE)
  66
  67     for line in file.xreadlines():
  68
  69         if line=="%%EndComments\n":
  70             # XXX: BoundingBox-Deklaration kann auch an Ende von Datei
  71             #      verschoben worden sein...
  72             #      ...but evaluation of such a bbox directive requires
  73             #      a parsing of the DSC!
  74             raise IOError, \
  75                   "bounding box not found in header of EPS file '%s'" % \
  76                   filename
  77
  78         bbmatch = bbpattern.match(line)
  79         if bbmatch is not None:
  80             # conversion strings->int
  81             (llx, lly, urx, ury) = map(int, bbmatch.groups())
  82             return bbox._bbox(llx, lly, urx, ury)
  83     else:
  84         raise IOError, \
  85               "bounding box not found in EPS file '%s'" % filename
  86
  87
  88 class epsfile(base.PSCmd):
  89
  90     """class for epsfiles"""
  91
  92     def __init__(self,
  93                  x, y, filename,
  94                  width=None, height=None, scale=None,
  95                  align="bl",
  96                  clip=1,
  97                  showbbox = 0,
  98                  translatebbox = 1):
  99         """inserts epsfile
 100
 101         inserts EPS file named filename at position (x,y).  If clip is
 102         set, the result gets clipped to the bbox of the EPS file. If
 103         translatebbox is not set, the EPS graphics is not translated to
 104         the corresponding origin. With showbb set, the bbox is drawn.
 105
 106         """
 107
 108         self._x = unit.topt(x)
 109         self._y = unit.topt(y)
 110         self.filename = filename
 111         self.mybbox = _readbbox(self.filename)
 112
 113         # determine scaling in x and y direction
 114         self.scalex = self.scaley = scale
 115
 116         if (width is not None or height is not None):
 117             if scale is not None:
 118                 raise ValueError("cannot set both width and/or height and scale simultaneously")
 119             if height is not None:
 120                 self.scalex = unit.topt(height)/(self.mybbox.urx-self.mybbox.llx)
 121             if width is not None:
 122                 self.scaley = unit.topt(width)/(self.mybbox.ury-self.mybbox.lly)
 123
 124             if self.scalex is None:
 125                 self.scalex = self.scaley
 126
 127             if self.scaley is None:
 128                 self.scaley = self.scalex
 129
 130         # set the actual width and height of the eps file (after a
 131         # possible scaling)
 132         self._width  = (self.mybbox.urx-self.mybbox.llx)
 133         if self.scalex:
 134             self._width *= self.scalex
 135
 136         self._height  = (self.mybbox.ury-self.mybbox.lly)
 137         if self.scaley:
 138             self._height *= self.scaley
 139
 140         # take alignment into account
 141         self.align       = align
 142         if self.align[0]=="b":
 143             pass
 144         elif self.align[0]=="c":
 145             self._y -= self._height/2.0
 146         elif self.align[0]=="t":
 147             self._y -= self._height
 148         else:
 149             raise ValueError("vertical alignment can only be b (bottom), c (center), or t (top)")
 150
 151         if self.align[1]=="l":
 152             pass
 153         elif self.align[1]=="c":
 154             self._x -= self._width/2.0
 155         elif self.align[1]=="r":
 156             self._x -= self._width
 157         else:
 158             raise ValueError("horizontal alignment can only be l (left), c (center), or r (right)")
 159
 160         self.clip = clip
 161         self.translatebbox = translatebbox
 162         self.showbbox = showbbox
 163
 164         self.trafo = trafo._translate(self._x, self._y)
 165
 166         if self.scalex is not None:
 167             self.trafo = self.trafo * trafo._scale(self.scalex, self.scaley)
 168
 169         if translatebbox:
 170             self.trafo = self.trafo * trafo._translate(-self.mybbox.llx, -self.mybbox.lly)
 171
 172     def bbox(self):
 173         return self.mybbox.transformed(self.trafo)
 174
 175     def prolog(self):
 176         return [_BeginEPSF, _EndEPSF]
 177
 178     def write(self, file):
 179         try:
 180             epsfile=open(self.filename,"r")
 181         except:
 182             raise IOError, "cannot open EPS file '%s'" % self.filename
 183
 184         file.write("BeginEPSF\n")
 185
 186         bbrect = self.mybbox.rect().transformed(self.trafo)
 187
 188         if self.showbbox:
 189             canvas._newpath().write(file)
 190             bbrect.write(file)
 191             canvas._stroke().write(file)
 192
 193         if self.clip:
 194             canvas._newpath().write(file)
 195             bbrect.write(file)
 196             canvas._clip().write(file)
 197
 198         self.trafo.write(file)
 199
 200         file.write("%%%%BeginDocument: %s\n" % self.filename)
 201         file.write(epsfile.read())
 202         file.write("%%EndDocument\n")
 203         file.write("EndEPSF\n")