epsfile.py

   1 # -*- encoding: utf-8 -*-
   2 #
   3 #
   4 # Copyright (C) 2002-2011 Jörg Lehmann <joergl@users.sourceforge.net>
   5 # Copyright (C) 2002-2011 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., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
  22
  23 import os, string, tempfile, warnings
  24 import canvasitem, bbox, filelocator, unit, trafo, pswriter
  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 = pswriter.PSdefinition("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 = pswriter.PSdefinition("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
  55 class linefilereader:
  56     """a line by line file reader
  57
  58     This line by line file reader allows for '\n', '\r' and
  59     '\r\n' as line separation characters. Line separation
  60     characters are not modified (binary mode). It implements
  61     a readline, a read and a close method similar to a regular
  62     file object."""
  63
  64     # note: '\n\r' is not considered to be a linebreak as its documented
  65     #       in the DSC spec #5001, while '\n\r' *is* a *single* linebreak
  66     #       according to the EPSF spec #5002
  67
  68     def __init__(self, file, typicallinelen=257):
  69         """Opens the file filename for reading.
  70
  71         typicallinelen defines the default buffer increase
  72         to find the next linebreak."""
  73
  74         # note: The maximal line size in an EPS is 255 plus the
  75         #       linebreak characters. However, we also handle
  76         #       lines longer than that.
  77         self.file = file
  78         self.buffer = ""
  79         self.typicallinelen = typicallinelen
  80
  81     def read(self, count=None, EOFmsg="unexpected end of file"):
  82         """read bytes from the file
  83
  84         count is the number of bytes to be read when set. Then count
  85         is unset, the rest of the file is returned. EOFmsg is used
  86         to raise a IOError, when the end of the file is reached while
  87         reading count bytes or when the rest of the file is empty when
  88         count is unset. When EOFmsg is set to None, less than the
  89         requested number of bytes might be returned."""
  90         if count is not None:
  91             if count > len(self.buffer):
  92                 self.buffer += self.file.read(count - len(self.buffer))
  93             if EOFmsg is not None and len(self.buffer) < count:
  94                 raise IOError(EOFmsg)
  95             result = self.buffer[:count]
  96             self.buffer = self.buffer[count:]
  97             return result
  98         else:
  99             self.buffer += self.file.read()
 100             if EOFmsg is not None and not len(self.buffer):
 101                 raise IOError(EOFmsg)
 102             result = self.buffer
 103             self.buffer = ""
 104             return result
 105
 106     def readline(self, EOFmsg="unexpected end of file"):
 107         """reads a line from the file
 108
 109         Lines are separated by '\n', '\r' or '\r\n'. The line separation
 110         strings are included in the return value. The last line might not
 111         end with an line separation string. Reading beyond the file generates
 112         an IOError with the EOFmsg message. When EOFmsg is None, an empty
 113         string is returned when reading beyond the end of the file."""
 114         EOF = 0
 115         while 1:
 116             crpos = self.buffer.find("\r")
 117             nlpos = self.buffer.find("\n")
 118             if nlpos == -1 and (crpos == -1 or crpos == len(self.buffer) - 1) and not EOF:
 119                 newbuffer = self.file.read(self.typicallinelen)
 120                 if not len(newbuffer):
 121                     EOF = 1
 122                 self.buffer += newbuffer
 123             else:
 124                 eol = len(self.buffer)
 125                 if not eol and EOFmsg is not None:
 126                     raise IOError(EOFmsg)
 127                 if nlpos != -1:
 128                     eol = nlpos + 1
 129                 if crpos != -1 and (nlpos == -1 or crpos < nlpos - 1):
 130                     eol = crpos + 1
 131                 result = self.buffer[:eol]
 132                 self.buffer = self.buffer[eol:]
 133                 return result
 134
 135     def close(self):
 136         "closes the file"
 137         self.file.close()
 138
 139
 140 def _readbbox(file):
 141     """returns bounding box of EPS file filename"""
 142
 143     file = linefilereader(file)
 144
 145     # check the %! header comment
 146     if not file.readline().startswith("%!"):
 147         raise IOError("file doesn't start with a '%!' header comment")
 148
 149     bboxatend = 0
 150     # parse the header (use the first BoundingBox)
 151     while 1:
 152         line = file.readline()
 153         if not line:
 154             break
 155         if line.startswith("%%BoundingBox:") and not bboxatend:
 156             values = line.split(":", 1)[1].split()
 157             if values == ["(atend)"]:
 158                 bboxatend = 1
 159             else:
 160                 if len(values) != 4:
 161                     raise IOError("invalid number of bounding box values")
 162                 return bbox.bbox_pt(*map(int, values))
 163         elif (line.rstrip() == "%%EndComments" or
 164               (len(line) >= 2 and line[0] != "%" and line[1] not in string.whitespace)):
 165             # implicit end of comments section
 166             break
 167     if not bboxatend:
 168         raise IOError("no bounding box information found")
 169
 170     # parse the body
 171     nesting = 0 # allow for nested documents
 172     while 1:
 173         line = file.readline()
 174         if line.startswith("%%BeginData:"):
 175             values = line.split(":", 1)[1].split()
 176             if len(values) > 3:
 177                 raise IOError("invalid number of arguments")
 178             if len(values) == 3:
 179                 if values[2] == "Lines":
 180                     for i in xrange(int(values[0])):
 181                         file.readline()
 182                 elif values[2] != "Bytes":
 183                     raise IOError("invalid bytesorlines-value")
 184                 else:
 185                     file.read(int(values[0]))
 186             else:
 187                 file.read(int(values[0]))
 188             line = file.readline()
 189             # ignore tailing whitespace/newline for binary data
 190             if (len(values) < 3 or values[2] != "Lines") and not len(line.strip()):
 191                 line = file.readline()
 192             if line.rstrip() != "%%EndData":
 193                 raise IOError("missing EndData")
 194         elif line.startswith("%%BeginBinary:"):
 195             file.read(int(line.split(":", 1)[1]))
 196             line = file.readline()
 197             # ignore tailing whitespace/newline
 198             if not len(line.strip()):
 199                 line = file.readline()
 200             if line.rstrip() != "%%EndBinary":
 201                 raise IOError("missing EndBinary")
 202         elif line.startswith("%%BeginDocument:"):
 203             nesting += 1
 204         elif line.rstrip() == "%%EndDocument":
 205             if nesting < 1:
 206                 raise IOError("unmatched EndDocument")
 207             nesting -= 1
 208         elif not nesting and line.rstrip() == "%%Trailer":
 209             break
 210
 211     usebbox = None
 212     # parse the trailer (use the last BoundingBox)
 213     line = True
 214     while line:
 215         line = file.readline(EOFmsg=None)
 216         if line.startswith("%%BoundingBox:"):
 217             values = line.split(":", 1)[1].split()
 218             if len(values) != 4:
 219                 raise IOError("invalid number of bounding box values")
 220             usebbox = bbox.bbox_pt(*map(int, values))
 221     if not usebbox:
 222         raise IOError("missing bounding box information in document trailer")
 223     return usebbox
 224
 225
 226 class epsfile(canvasitem.canvasitem):
 227
 228     """class for epsfiles"""
 229
 230     def __init__(self,
 231                  x, y, filename,
 232                  width=None, height=None, scale=None, align="bl",
 233                  clip=1, translatebbox=1, bbox=None,
 234                  kpsearch=0):
 235         """inserts epsfile
 236
 237         Object for an EPS file named filename at position (x,y). Width, height,
 238         scale and aligment can be adjusted by the corresponding parameters. If
 239         clip is set, the result gets clipped to the bbox of the EPS file. If
 240         translatebbox is not set, the EPS graphics is not translated to the
 241         corresponding origin. If bbox is not None, it overrides the bounding
 242         box in the epsfile itself. If kpsearch is set then filename is searched
 243         using the kpathsea library.
 244         """
 245
 246         self.x_pt = unit.topt(x)
 247         self.y_pt = unit.topt(y)
 248         self.filename = filename
 249         self.kpsearch = kpsearch
 250         if bbox:
 251             self.mybbox = bbox
 252         else:
 253             epsfile = self.open()
 254             self.mybbox = _readbbox(epsfile)
 255             epsfile.close()
 256
 257         # determine scaling in x and y direction
 258         self.scalex = self.scaley = scale
 259
 260         if width is not None or height is not None:
 261             if scale is not None:
 262                 raise ValueError("cannot set both width and/or height and scale simultaneously")
 263             if height is not None:
 264                 self.scaley = unit.topt(height)/(self.mybbox.ury_pt-self.mybbox.lly_pt)
 265             if width is not None:
 266                 self.scalex = unit.topt(width)/(self.mybbox.urx_pt-self.mybbox.llx_pt)
 267
 268             if self.scalex is None:
 269                 self.scalex = self.scaley
 270             if self.scaley is None:
 271                 self.scaley = self.scalex
 272
 273         # set the actual width and height of the eps file (after a
 274         # possible scaling)
 275         self.width_pt  = self.mybbox.urx_pt-self.mybbox.llx_pt
 276         if self.scalex:
 277             self.width_pt *= self.scalex
 278
 279         self.height_pt = self.mybbox.ury_pt-self.mybbox.lly_pt
 280         if self.scaley:
 281             self.height_pt *= self.scaley
 282
 283         # take alignment into account
 284         self.align       = align
 285         if self.align[0]=="b":
 286             pass
 287         elif self.align[0]=="c":
 288             self.y_pt -= self.height_pt/2.0
 289         elif self.align[0]=="t":
 290             self.y_pt -= self.height_pt
 291         else:
 292             raise ValueError("vertical alignment can only be b (bottom), c (center), or t (top)")
 293
 294         if self.align[1]=="l":
 295             pass
 296         elif self.align[1]=="c":
 297             self.x_pt -= self.width_pt/2.0
 298         elif self.align[1]=="r":
 299             self.x_pt -= self.width_pt
 300         else:
 301             raise ValueError("horizontal alignment can only be l (left), c (center), or r (right)")
 302
 303         self.clip = clip
 304         self.translatebbox = translatebbox
 305
 306         self.trafo = trafo.translate_pt(self.x_pt, self.y_pt)
 307
 308         if self.scalex is not None:
 309             self.trafo = self.trafo * trafo.scale_pt(self.scalex, self.scaley)
 310
 311         if translatebbox:
 312             self.trafo = self.trafo * trafo.translate_pt(-self.mybbox.llx_pt, -self.mybbox.lly_pt)
 313
 314     def open(self):
 315         if self.kpsearch:
 316             return filelocator.open(self.filename, [filelocator.format.pict], "rb")
 317         else:
 318             return open(self.filename, "rb")
 319
 320     def bbox(self):
 321         return self.mybbox.transformed(self.trafo)
 322
 323     def processPS(self, file, writer, context, registry, bbox):
 324         registry.add(_BeginEPSF)
 325         registry.add(_EndEPSF)
 326         bbox += self.bbox()
 327
 328         file.write("BeginEPSF\n")
 329
 330         if self.clip:
 331             llx_pt, lly_pt, urx_pt, ury_pt = self.mybbox.transformed(self.trafo).highrestuple_pt()
 332             file.write("%g %g %g %g rectclip\n" % (llx_pt, lly_pt, urx_pt-llx_pt, ury_pt-lly_pt))
 333
 334         self.trafo.processPS(file, writer, context, registry, bbox)
 335
 336         file.write("%%%%BeginDocument: %s\n" % self.filename)
 337
 338         epsfile = self.open()
 339         file.write(epsfile.read())
 340         epsfile.close()
 341
 342         file.write("%%EndDocument\n")
 343         file.write("EndEPSF\n")
 344
 345     def processPDF(self, file, writer, context, registry, bbox):
 346         warnings.warn("EPS file is included as a bitmap created using pipeGS")
 347         from pyx import bitmap, canvas
 348         try:
 349             from PIL import Image
 350         except ImportError:
 351             import Image
 352         c = canvas.canvas()
 353         c.insert(self)
 354         i = Image.open(c.pipeGS(device="pngalpha", resolution=600, seekable=True))
 355         i.load()
 356         b = bitmap.bitmap_pt(self.bbox().llx_pt, self.bbox().lly_pt, i)
 357         # we slightly shift the bitmap to re-center it, as the bitmap might contain some additional border
 358         # unfortunately we need to construct another bitmap instance for that ...
 359         b = bitmap.bitmap_pt(self.bbox().llx_pt + 0.5*(self.bbox().width_pt()-b.bbox().width_pt()),
 360                              self.bbox().lly_pt + 0.5*(self.bbox().height_pt()-b.bbox().height_pt()), i)
 361         b.processPDF(file, writer, context, registry, bbox)