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, path, unit, trafo
  25
  26 # PostScript-procedure definitions
  27 # cf. file: 5002.EPSF_Spec_v3.0.pdf
  28 # with important correction in EndEPSF:
  29 #   end operator is missing in the spec!
  30
  31 _BeginEPSF = canvas.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 = canvas.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     for line in file.xreadlines():
  69
  70         if line=="%%EndComments\n":
  71             # TODO: BoundingBox-Deklaration kann auch an Ende von Datei
  72             #       verschoben worden sein...
  73             #       ...but evaluation of such a bbox directive requires
  74             #       a parsing of the DSC!
  75             raise IOError, \
  76                   "bounding box not found in header of EPS file '%s'" % \
  77                   filename
  78
  79         bbmatch = bbpattern.match(line)
  80         if bbmatch is not None:
  81             # conversion strings->int
  82             (llx, lly, urx, ury) = map(int, bbmatch.groups())
  83             return bbox.bbox(llx, lly, urx, ury)
  84     else:
  85         raise IOError, \
  86               "bounding box not found in EPS file '%s'" % filename
  87
  88
  89 class epsfile(base.PSCmd):
  90
  91     """class for epsfiles"""
  92
  93     def __init__(self,
  94                  filename,
  95                  x = "0 t m", y = "0 t m",
  96                  width = None, height = None, scale=None,
  97                  align = "bl",
  98                  clip = 1,
  99                  showbbox = 0,
 100                  translatebbox = 1):
 101         """inserts epsfile
 102
 103         inserts EPS file named filename at position (x,y).  If clip is
 104         set, the result gets clipped to the bbox of the EPS file. If
 105         translatebbox is not set, the EPS graphics is not translated to
 106         the corresponding origin. With showbb set, the bbox is drawn.
 107
 108         """
 109
 110         self.filename    = filename
 111         self.mybbox      = _readbbox(self.filename)
 112
 113         self._x           = unit.topt(x)
 114         self._y           = unit.topt(y)
 115
 116         # determine scaling in x and y direction
 117         self.scalex = self.scaley = scale
 118
 119         if (width is not None or height is not None):
 120             if scale is not None:
 121                 raise ValueError("cannot set both width and/or height and scale simultaneously")
 122             if height is not None:
 123                 self.scalex = unit.topt(height)/(self.mybbox.urx-self.mybbox.llx)
 124             if width is not None:
 125                 self.scaley = unit.topt(width)/(self.mybbox.ury-self.mybbox.lly)
 126
 127             if self.scalex is None:
 128                 self.scalex = self.scaley
 129
 130             if self.scaley is None:
 131                 self.scaley = self.scalex
 132
 133         # now, we set the actual width and height of the eps file (after a
 134         # possible scaling)
 135         self._width  = (self.mybbox.urx-self.mybbox.llx)
 136         if self.scalex:
 137             self._width *= self.scalex
 138
 139         self._height  = (self.mybbox.ury-self.mybbox.lly)
 140         if self.scaley:
 141             self._height *= self.scaley
 142
 143         # take alignment into account
 144         self.align       = align
 145         if self.align[0]=="b":
 146             pass
 147         elif self.align[0]=="c":
 148             self._y -= self._height/2.0
 149         elif self.align[0]=="t":
 150             self._y -= self._height
 151         else:
 152             raise ValueError("vertical alignment can only be b (bottom), c (center), or t (top)")
 153
 154         if self.align[1]=="l":
 155             pass
 156         elif self.align[1]=="c":
 157             self._x -= self._width/2.0
 158         elif self.align[1]=="r":
 159             self._x -= self._width
 160         else:
 161             raise ValueError("horizontal alignment can only be l (left), c (center), or r (right)")
 162
 163         self.clip = clip
 164         self.translatebbox = translatebbox
 165         self.showbbox = showbbox
 166
 167         self.trafo = trafo._translate(self._x, self._y)
 168
 169         if self.scalex is not None:
 170             self.trafo = self.trafo * trafo._scale(self.scalex, self.scaley)
 171
 172         if translatebbox:
 173             self.trafo = self.trafo * trafo._translate(-self.mybbox.llx, -self.mybbox.lly)
 174
 175     def bbox(self):
 176         return self.mybbox.transformed(self.trafo)
 177
 178     def prologue(self):
 179         return [_BeginEPSF, _EndEPSF]
 180
 181     def write(self, file):
 182         try:
 183             epsfile=open(self.filename,"r")
 184         except:
 185             raise IOError, "cannot open EPS file '%s'" % self.filename
 186
 187         file.write("BeginEPSF\n")
 188
 189
 190
 191         bbrect = self.mybbox.rect().transformed(self.trafo)
 192
 193         if self.showbbox:
 194             canvas._newpath().write(file)
 195             bbrect.write(file)
 196             canvas._stroke().write(file)
 197
 198         if self.clip:
 199             canvas._newpath().write(file)
 200             bbrect.write(file)
 201             canvas._clip().write(file)
 202
 203         self.trafo.write(file)
 204
 205         file.write("%%%%BeginDocument: %s\n" % self.filename)
 206         file.write(epsfile.read())
 207         file.write("%%EndDocument\n")
 208         file.write("EndEPSF\n")