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 logging, os, string, tempfile
  24 from . import baseclasses, bbox, config, unit, trafo, pswriter
  25
  26 logger = logging.getLogger("pyx")
  27
  28 # PostScript-procedure definitions (cf. 5002.EPSF_Spec_v3.0.pdf)
  29 # with important correction in EndEPSF:
  30 #   end operator is missing in the spec!
  31
  32 _BeginEPSF = pswriter.PSdefinition("BeginEPSF", b"""{
  33   /b4_Inc_state save def
  34   /dict_count countdictstack def
  35   /op_count count 1 sub def
  36   userdict begin
  37   /showpage { } def
  38   0 setgray 0 setlinecap
  39   1 setlinewidth 0 setlinejoin
  40   10 setmiterlimit [ ] 0 setdash newpath
  41   /languagelevel where
  42   {pop languagelevel
  43   1 ne
  44     {false setstrokeadjust false setoverprint
  45     } if
  46   } if
  47 } bind""")
  48
  49 _EndEPSF = pswriter.PSdefinition("EndEPSF", b"""{
  50   end
  51   count op_count sub {pop} repeat
  52   countdictstack dict_count sub {end} repeat
  53   b4_Inc_state restore
  54 } bind""")
  55
  56
  57 class linefilereader:
  58     """a line by line file reader
  59
  60     This line by line file reader allows for '\n', '\r' and
  61     '\r\n' as line separation characters. Line separation
  62     characters are not modified (binary mode). It implements
  63     a readline, a read and a close method similar to a regular
  64     file object."""
  65
  66     # note: '\n\r' is not considered to be a linebreak as its documented
  67     #       in the DSC spec #5001, while '\n\r' *is* a *single* linebreak
  68     #       according to the EPSF spec #5002
  69
  70     def __init__(self, file, typicallinelen=257):
  71         """Opens the file filename for reading.
  72
  73         typicallinelen defines the default buffer increase
  74         to find the next linebreak."""
  75
  76         # note: The maximal line size in an EPS is 255 plus the
  77         #       linebreak characters. However, we also handle
  78         #       lines longer than that.
  79         self.file = file
  80         self.buffer = b""
  81         self.typicallinelen = typicallinelen
  82
  83     def read(self, count=None, EOFmsg="unexpected end of file"):
  84         """read bytes from the file
  85
  86         count is the number of bytes to be read when set. Then count
  87         is unset, the rest of the file is returned. EOFmsg is used
  88         to raise a IOError, when the end of the file is reached while
  89         reading count bytes or when the rest of the file is empty when
  90         count is unset. When EOFmsg is set to None, less than the
  91         requested number of bytes might be returned."""
  92         if count is not None:
  93             if count > len(self.buffer):
  94                 self.buffer += self.file.read(count - len(self.buffer))
  95             if EOFmsg is not None and len(self.buffer) < count:
  96                 raise IOError(EOFmsg)
  97             result = self.buffer[:count]
  98             self.buffer = self.buffer[count:]
  99             return result
 100         else:
 101             self.buffer += self.file.read()
 102             if EOFmsg is not None and not len(self.buffer):
 103                 raise IOError(EOFmsg)
 104             result = self.buffer
 105             self.buffer = ""
 106             return result
 107
 108     def readline(self, EOFmsg="unexpected end of file"):
 109         """reads a line from the file
 110
 111         Lines are separated by '\n', '\r' or '\r\n'. The line separation
 112         strings are included in the return value. The last line might not
 113         end with an line separation string. Reading beyond the file generates
 114         an IOError with the EOFmsg message. When EOFmsg is None, an empty
 115         string is returned when reading beyond the end of the file."""
 116         EOF = 0
 117         while True:
 118             crpos = self.buffer.find(b"\r")
 119             nlpos = self.buffer.find(b"\n")
 120             if nlpos == -1 and (crpos == -1 or crpos == len(self.buffer) - 1) and not EOF:
 121                 newbuffer = self.file.read(self.typicallinelen)
 122                 if not len(newbuffer):
 123                     EOF = 1
 124                 self.buffer += newbuffer
 125             else:
 126                 eol = len(self.buffer)
 127                 if not eol and EOFmsg is not None:
 128                     raise IOError(EOFmsg)
 129                 if nlpos != -1:
 130                     eol = nlpos + 1
 131                 if crpos != -1 and (nlpos == -1 or crpos < nlpos - 1):
 132                     eol = crpos + 1
 133                 result = self.buffer[:eol]
 134                 self.buffer = self.buffer[eol:]
 135                 return result
 136
 137
 138 def _readbbox(file):
 139     """returns bounding box of EPS file filename"""
 140
 141     file = linefilereader(file)
 142
 143     # check the %! header comment
 144     if not file.readline().startswith(b"%!"):
 145         raise IOError("file doesn't start with a '%!' header comment")
 146
 147     bboxatend = 0
 148     # parse the header (use the first BoundingBox)
 149     while True:
 150         line = file.readline()
 151         if not line:
 152             break
 153         if line.startswith(b"%%BoundingBox:") and not bboxatend:
 154             values = line.split(b":", 1)[1].split()
 155             if values == ["(atend)"]:
 156                 bboxatend = 1
 157             else:
 158                 if len(values) != 4:
 159                     raise IOError("invalid number of bounding box values")
 160                 return bbox.bbox_pt(*list(map(int, values)))
 161         elif (line.rstrip() == b"%%EndComments" or
 162               (len(line) >= 2 and chr(line[0]) != "%" and chr(line[1]) not in string.whitespace)):
 163             # implicit end of comments section
 164             break
 165     if not bboxatend:
 166         raise IOError("no bounding box information found")
 167
 168     # parse the body
 169     nesting = 0 # allow for nested documents
 170     while True:
 171         line = file.readline()
 172         if line.startswith(b"%%BeginData:"):
 173             values = line.split(":", 1)[1].split()
 174             if len(values) > 3:
 175                 raise IOError("invalid number of arguments")
 176             if len(values) == 3:
 177                 if values[2] == b"Lines":
 178                     for i in range(int(values[0])):
 179                         file.readline()
 180                 elif values[2] != b"Bytes":
 181                     raise IOError("invalid bytesorlines-value")
 182                 else:
 183                     file.read(int(values[0]))
 184             else:
 185                 file.read(int(values[0]))
 186             line = file.readline()
 187             # ignore tailing whitespace/newline for binary data
 188             if (len(values) < 3 or values[2] != "Lines") and not len(line.strip()):
 189                 line = file.readline()
 190             if line.rstrip() != b"%%EndData":
 191                 raise IOError("missing EndData")
 192         elif line.startswith(b"%%BeginBinary:"):
 193             file.read(int(line.split(":", 1)[1]))
 194             line = file.readline()
 195             # ignore tailing whitespace/newline
 196             if not len(line.strip()):
 197                 line = file.readline()
 198             if line.rstrip() != b"%%EndBinary":
 199                 raise IOError("missing EndBinary")
 200         elif line.startswith(b"%%BeginDocument:"):
 201             nesting += 1
 202         elif line.rstrip() == b"%%EndDocument":
 203             if nesting < 1:
 204                 raise IOError("unmatched EndDocument")
 205             nesting -= 1
 206         elif not nesting and line.rstrip() == b"%%Trailer":
 207             break
 208
 209     usebbox = None
 210     # parse the trailer (use the last BoundingBox)
 211     line = True
 212     while line:
 213         line = file.readline(EOFmsg=None)
 214         if line.startswith("%%BoundingBox:"):
 215             values = line.split(b":", 1)[1].split()
 216             if len(values) != 4:
 217                 raise IOError("invalid number of bounding box values")
 218             usebbox = bbox.bbox_pt(*list(map(int, values)))
 219     if not usebbox:
 220         raise IOError("missing bounding box information in document trailer")
 221     return usebbox
 222
 223
 224 class epsfile(baseclasses.canvasitem):
 225
 226     """class for epsfiles"""
 227
 228     def __init__(self,
 229                  x, y, filename,
 230                  width=None, height=None, scale=None, align="bl",
 231                  clip=1, translatebbox=1, bbox=None,
 232                  kpsearch=0):
 233         """inserts epsfile
 234
 235         Object for an EPS file named filename at position (x,y). Width, height,
 236         scale and aligment can be adjusted by the corresponding parameters. If
 237         clip is set, the result gets clipped to the bbox of the EPS file. If
 238         translatebbox is not set, the EPS graphics is not translated to the
 239         corresponding origin. If bbox is not None, it overrides the bounding
 240         box in the epsfile itself. If kpsearch is set then filename is searched
 241         using the kpathsea library.
 242         """
 243
 244         self.x_pt = unit.topt(x)
 245         self.y_pt = unit.topt(y)
 246         self.filename = filename
 247         self.kpsearch = kpsearch
 248         if bbox:
 249             self.mybbox = bbox
 250         else:
 251             with self.open() as epsfile:
 252                 self.mybbox = _readbbox(epsfile)
 253
 254         # determine scaling in x and y direction
 255         self.scalex = self.scaley = scale
 256
 257         if width is not None or height is not None:
 258             if scale is not None:
 259                 raise ValueError("cannot set both width and/or height and scale simultaneously")
 260             if height is not None:
 261                 self.scaley = unit.topt(height)/(self.mybbox.ury_pt-self.mybbox.lly_pt)
 262             if width is not None:
 263                 self.scalex = unit.topt(width)/(self.mybbox.urx_pt-self.mybbox.llx_pt)
 264
 265             if self.scalex is None:
 266                 self.scalex = self.scaley
 267             if self.scaley is None:
 268                 self.scaley = self.scalex
 269
 270         # set the actual width and height of the eps file (after a
 271         # possible scaling)
 272         self.width_pt  = self.mybbox.urx_pt-self.mybbox.llx_pt
 273         if self.scalex:
 274             self.width_pt *= self.scalex
 275
 276         self.height_pt = self.mybbox.ury_pt-self.mybbox.lly_pt
 277         if self.scaley:
 278             self.height_pt *= self.scaley
 279
 280         # take alignment into account
 281         self.align       = align
 282         if self.align[0]=="b":
 283             pass
 284         elif self.align[0]=="c":
 285             self.y_pt -= self.height_pt/2.0
 286         elif self.align[0]=="t":
 287             self.y_pt -= self.height_pt
 288         else:
 289             raise ValueError("vertical alignment can only be b (bottom), c (center), or t (top)")
 290
 291         if self.align[1]=="l":
 292             pass
 293         elif self.align[1]=="c":
 294             self.x_pt -= self.width_pt/2.0
 295         elif self.align[1]=="r":
 296             self.x_pt -= self.width_pt
 297         else:
 298             raise ValueError("horizontal alignment can only be l (left), c (center), or r (right)")
 299
 300         self.clip = clip
 301         self.translatebbox = translatebbox
 302
 303         self.trafo = trafo.translate_pt(self.x_pt, self.y_pt)
 304
 305         if self.scalex is not None:
 306             self.trafo = self.trafo * trafo.scale_pt(self.scalex, self.scaley)
 307
 308         if translatebbox:
 309             self.trafo = self.trafo * trafo.translate_pt(-self.mybbox.llx_pt, -self.mybbox.lly_pt)
 310
 311     def open(self):
 312         if self.kpsearch:
 313             return config.open(self.filename, [config.format.pict])
 314         else:
 315             return open(self.filename, "rb")
 316
 317     def bbox(self):
 318         return self.mybbox.transformed(self.trafo)
 319
 320     def processPS(self, file, writer, context, registry, bbox):
 321         registry.add(_BeginEPSF)
 322         registry.add(_EndEPSF)
 323         bbox += self.bbox()
 324
 325         file.write("BeginEPSF\n")
 326
 327         if self.clip:
 328             llx_pt, lly_pt, urx_pt, ury_pt = self.mybbox.transformed(self.trafo).highrestuple_pt()
 329             file.write("%g %g %g %g rectclip\n" % (llx_pt, lly_pt, urx_pt-llx_pt, ury_pt-lly_pt))
 330
 331         self.trafo.processPS(file, writer, context, registry)
 332
 333         file.write("%%%%BeginDocument: %s\n" % self.filename)
 334
 335         with self.open() as epsfile:
 336             file.write_bytes(epsfile.read())
 337
 338         file.write("%%EndDocument\n")
 339         file.write("EndEPSF\n")
 340
 341     def processPDF(self, file, writer, context, registry, bbox):
 342         logger.warning("EPS file is included as a bitmap created using pipeGS")
 343         from pyx import bitmap, canvas
 344         from PIL import Image
 345         c = canvas.canvas()
 346         c.insert(self)
 347         i = Image.open(c.pipeGS(device="pngalpha", resolution=600))
 348         i.load()
 349         b = bitmap.bitmap_pt(self.bbox().llx_pt, self.bbox().lly_pt, i)
 350         # we slightly shift the bitmap to re-center it, as the bitmap might contain some additional border
 351         # unfortunately we need to construct another bitmap instance for that ...
 352         b = bitmap.bitmap_pt(self.bbox().llx_pt + 0.5*(self.bbox().width_pt()-b.bbox().width_pt()),
 353                              self.bbox().lly_pt + 0.5*(self.bbox().height_pt()-b.bbox().height_pt()), i)
 354         b.processPDF(file, writer, context, registry, bbox)