pyx/font/font.py

   1 # -*- coding: ISO-8859-1 -*-
   2 #
   3 #
   4 # Copyright (C) 2005-2007 Jörg Lehmann <joergl@users.sourceforge.net>
   5 # Copyright (C) 2005-2007 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 from pyx import bbox, canvasitem, pswriter, trafo, unit
  24 import t1file
  25
  26 try:
  27     set()
  28 except NameError:
  29     # Python 2.3
  30     from sets import Set as set
  31
  32 #
  33 # PSresources
  34 #
  35
  36
  37 class PST1file(pswriter.PSresource):
  38
  39     """ PostScript font definition included in the prolog """
  40
  41     def __init__(self, t1file, glyphnames, charcodes):
  42         """ include type 1 font t1file stripped to the given glyphnames"""
  43         self.type = "t1file"
  44         self.t1file = t1file
  45         self.id = t1file.name
  46         self.glyphnames = set(glyphnames)
  47         self.charcodes = set(charcodes)
  48         self.strip = 1
  49
  50     def merge(self, other):
  51         self.glyphnames.update(other.glyphnames)
  52         self.charcodes.update(other.charcodes)
  53
  54     def output(self, file, writer, registry):
  55         file.write("%%%%BeginFont: %s\n" % self.t1file.name)
  56         if self.strip:
  57             if self.glyphnames:
  58                 file.write("%%Included glyphs: %s\n" % " ".join(self.glyphnames))
  59             if self.charcodes:
  60                 file.write("%%Included charcodes: %s\n" % " ".join([str(charcode) for charcode in self.charcodes]))
  61             self.t1file.getstrippedfont(self.glyphnames, self.charcodes).outputPS(file, writer)
  62         else:
  63             self.t1file.outputPS(file, writer)
  64         file.write("\n%%EndFont\n")
  65
  66
  67 _ReEncodeFont = pswriter.PSdefinition("ReEncodeFont", """{
  68   5 dict
  69   begin
  70     /newencoding exch def
  71     /newfontname exch def
  72     /basefontname exch def
  73     /basefontdict basefontname findfont def
  74     /newfontdict basefontdict maxlength dict def
  75     basefontdict {
  76       exch dup dup /FID ne exch /Encoding ne and
  77       { exch newfontdict 3 1 roll put }
  78       { pop pop }
  79       ifelse
  80     } forall
  81     newfontdict /FontName newfontname put
  82     newfontdict /Encoding newencoding put
  83     newfontname newfontdict definefont pop
  84   end
  85 }""")
  86
  87
  88 class PSreencodefont(pswriter.PSresource):
  89
  90     """ reencoded PostScript font"""
  91
  92     def __init__(self, basefontname, newfontname, encoding):
  93         """ reencode the font """
  94
  95         self.type = "reencodefont"
  96         self.basefontname = basefontname
  97         self.id = self.newfontname = newfontname
  98         self.encoding = encoding
  99
 100     def output(self, file, writer, registry):
 101         file.write("%%%%BeginResource: %s\n" % self.newfontname)
 102         file.write("/%s /%s\n[" % (self.basefontname, self.newfontname))
 103         vector = [None] * len(self.encoding)
 104         for glyphname, charcode in self.encoding.items():
 105             vector[charcode] = glyphname
 106         for i, glyphname in enumerate(vector):
 107             if i:
 108                 if not (i % 8):
 109                     file.write("\n")
 110                 else:
 111                     file.write(" ")
 112             file.write("/%s" % glyphname)
 113         file.write("]\n")
 114         file.write("ReEncodeFont\n")
 115         file.write("%%EndResource\n")
 116
 117
 118 _ChangeFontMatrix = pswriter.PSdefinition("ChangeFontMatrix", """{
 119   5 dict
 120   begin
 121     /newfontmatrix exch def
 122     /newfontname exch def
 123     /basefontname exch def
 124     /basefontdict basefontname findfont def
 125     /newfontdict basefontdict maxlength dict def
 126     basefontdict {
 127       exch dup dup /FID ne exch /FontMatrix ne and
 128       { exch newfontdict 3 1 roll put }
 129       { pop pop }
 130       ifelse
 131     } forall
 132     newfontdict /FontName newfontname put
 133     newfontdict /FontMatrix newfontmatrix readonly put
 134     newfontname newfontdict definefont pop
 135   end
 136 }""")
 137
 138
 139 class PSchangefontmatrix(pswriter.PSresource):
 140
 141     """ change font matrix of a PostScript font"""
 142
 143     def __init__(self, basefontname, newfontname, newfontmatrix):
 144         """ change the font matrix """
 145
 146         self.type = "changefontmatrix"
 147         self.basefontname = basefontname
 148         self.id = self.newfontname = newfontname
 149         self.newfontmatrix = newfontmatrix
 150
 151     def output(self, file, writer, registry):
 152         file.write("%%%%BeginResource: %s\n" % self.newfontname)
 153         file.write("/%s /%s\n" % (self.basefontname, self.newfontname))
 154         file.write(str(self.newfontmatrix))
 155         file.write("\nChangeFontMatrix\n")
 156         file.write("%%EndResource\n")
 157
 158
 159 class font:
 160
 161     def text(self, x, y, charcodes, size_pt, **kwargs):
 162         return self.text_pt(unit.topt(x), unit.topt(y), charcodes, size_pt, **kwargs)
 163
 164
 165 class T1font(font):
 166
 167     def __init__(self, t1file, metric):
 168         self.t1file = t1file
 169         self.name = t1file.name
 170         self.metric = metric
 171
 172     def text_pt(self, x, y, charcodes, size_pt, **kwargs):
 173         return T1text_pt(self, x, y, charcodes, size_pt, **kwargs)
 174
 175
 176 class T1builtinfont(T1font):
 177
 178     def __init__(self, name, metric):
 179         self.name = name
 180         self.t1file = None
 181         self.metric = metric
 182
 183
 184 class selectedfont:
 185
 186     def __init__(self, name, size_pt):
 187         self.name = name
 188         self.size_pt = size_pt
 189
 190     def __eq__(self, other):
 191         return self.name == other.name and self.size_pt == other.size_pt
 192
 193     def outputPS(self, file, writer):
 194         file.write("/%s %f selectfont\n" % (self.name, self.size_pt))
 195
 196
 197 class text_pt(canvasitem.canvasitem):
 198
 199     pass
 200
 201
 202 class T1text_pt(text_pt):
 203
 204     def __init__(self, font, x_pt, y_pt, charcodes, size_pt, decoding=None, slant=None, ignorebbox=False): #, **features):
 205         # features: kerning, ligatures
 206         if decoding is not None:
 207             self.glyphnames = [decoding[character] for character in charcodes]
 208             self.reencode = True
 209         else:
 210             self.charcodes = charcodes
 211             self.reencode = False
 212         self.font = font
 213         self.x_pt = x_pt
 214         self.y_pt = y_pt
 215         self.size_pt = size_pt
 216         self.slant = slant
 217         self.ignorebbox = ignorebbox
 218
 219     def bbox(self):
 220         if self.font.metric is None:
 221             raise NotImplementedError("we don't yet have access to the metric")
 222         return bbox.bbox_pt(self.x_pt,
 223                             self.y_pt-self.font.metric.depth_pt(self.glyphnames, self.size_pt),
 224                             self.x_pt+self.font.metric.width_pt(self.glyphnames, self.size_pt),
 225                             self.y_pt+self.font.metric.height_pt(self.glyphnames, self.size_pt))
 226
 227     def getencodingname(self, encodings):
 228         """returns the name of the encoding (in encodings) mapping self.glyphnames to codepoints
 229         If no such encoding can be found or extended, a new encoding is added to encodings
 230         """
 231         glyphnames = set(self.glyphnames)
 232         if len(glyphnames) > 256:
 233             raise ValueError("glyphs do not fit into one single encoding")
 234         for encodingname, encoding in encodings.items():
 235             glyphsmissing = []
 236             for glyphname in glyphnames:
 237                 if glyphname not in encoding.keys():
 238                     glyphsmissing.append(glyphname)
 239
 240             if len(glyphsmissing) + len(encoding) < 256:
 241                 # new glyphs fit in existing encoding which will thus be extended
 242                 for glyphname in glyphsmissing:
 243                     encoding[glyphname] = len(encoding)
 244                 return encodingname
 245         # create a new encoding for the glyphnames
 246         encodingname = "encoding%d" % len(encodings)
 247         encodings[encodingname] = dict([(glyphname, i) for i, glyphname in enumerate(glyphnames)])
 248         return encodingname
 249
 250     def processPS(self, file, writer, context, registry, bbox):
 251         if not self.ignorebbox:
 252             bbox += self.bbox()
 253
 254         # register resources
 255         if self.font.t1file is not None:
 256             if self.reencode:
 257                 registry.add(PST1file(self.font.t1file, self.glyphnames, []))
 258             else:
 259                 registry.add(PST1file(self.font.t1file, [], self.charcodes))
 260
 261         fontname = self.font.name
 262         if self.reencode:
 263             encodingname = self.getencodingname(context.encodings.setdefault(self.font.name, {}))
 264             encoding = context.encodings[self.font.name][encodingname]
 265             newfontname = "%s-%s" % (fontname, encodingname)
 266             registry.add(_ReEncodeFont)
 267             registry.add(PSreencodefont(fontname, newfontname, encoding))
 268             fontname = newfontname
 269
 270         if self.slant:
 271             newfontmatrix = trafo.trafo_pt(matrix=((1, self.slant), (0, 1))) * self.font.t1file.fontmatrix
 272             newfontname = "%s-slant%f" % (fontname, self.slant)
 273             registry.add(_ChangeFontMatrix)
 274             registry.add(PSchangefontmatrix(fontname, newfontname, newfontmatrix))
 275             fontname = newfontname
 276
 277
 278         # select font if necessary
 279         sf = selectedfont(fontname, self.size_pt)
 280         if context.selectedfont is None or sf != context.selectedfont:
 281             context.selectedfont = sf
 282             sf.outputPS(file, writer)
 283
 284         file.write("%f %f moveto (" % (self.x_pt, self.y_pt))
 285         if self.reencode:
 286             charcodes = [encoding[glyphname] for glyphname in self.glyphnames]
 287         else:
 288             charcodes = self.charcodes
 289         for charcode in charcodes:
 290             if 32 < charcode < 127 and chr(charcode) not in "()[]<>\\":
 291                 file.write("%s" % chr(charcode))
 292             else:
 293                 file.write("\\%03o" % charcode)
 294         file.write(") show\n")