#Copyright ReportLab Europe Ltd. 2000-2004 #see license.txt for license details #history http://www.reportlab.co.uk/cgi-bin/viewcvs.cgi/public/reportlab/trunk/reportlab/pdfbase/ttfonts.py """TrueType font support This defines classes to represent TrueType fonts. They know how to calculate their own width and how to write themselves into PDF files. They support subsetting and embedding and can represent all 16-bit Unicode characters. Note on dynamic fonts --------------------- Usually a Font in ReportLab corresponds to a fixed set of PDF objects (Font, FontDescriptor, Encoding). But with dynamic font subsetting a single TTFont will result in a number of Font/FontDescriptor/Encoding object sets, and the contents of those will depend on the actual characters used for printing. To support dynamic font subsetting a concept of "dynamic font" was introduced. Dynamic Fonts have a _dynamicFont attribute set to 1. Since other Font object may lack a this attribute, you should use constructs like if getattr(font, '_dynamicFont', 0): # dynamic font else: # traditional static font Dynamic fonts have the following additional functions: def splitString(self, text, doc): '''Splits text into a number of chunks, each of which belongs to a single subset. Returns a list of tuples (subset, string). Use subset numbers with getSubsetInternalName. Doc is used to identify a document so that different documents may have different dynamically constructed subsets.''' def getSubsetInternalName(self, subset, doc): '''Returns the name of a PDF Font object corresponding to a given subset of this dynamic font. Use this function instead of PDFDocument.getInternalFontName.''' You must never call PDFDocument.getInternalFontName for dynamic fonts. If you have a traditional static font, mapping to PDF text output operators is simple: '%s 14 Tf (%s) Tj' % (getInternalFontName(psfontname), text) If you have a dynamic font, use this instead: for subset, chunk in font.splitString(text, doc): '%s 14 Tf (%s) Tj' % (font.getSubsetInternalName(subset, doc), chunk) (Tf is a font setting operator and Tj is a text ouput operator. You should also escape invalid characters in Tj argument, see TextObject._formatText. Oh, and that 14 up there is font size.) Canvas and TextObject have special support for dynamic fonts. """ __version__ = '$Id$' import string from types import StringType from struct import pack, unpack from cStringIO import StringIO from reportlab.pdfbase import pdfmetrics, pdfdoc def _L2U32(L): return unpack('l',pack('L',L))[0] class TTFError(pdfdoc.PDFError): "TrueType font exception" pass # # Helpers # from codecs import utf_8_encode, utf_8_decode, latin_1_decode parse_utf8=lambda x, decode=utf_8_decode: map(ord,decode(x)[0]) parse_latin1 = lambda x, decode=latin_1_decode: map(ord,decode(x)[0]) def latin1_to_utf8(text): "helper to convert when needed from latin input" return utf_8_encode(latin_1_decode(text)[0])[0] def makeToUnicodeCMap(fontname, subset): """Creates a ToUnicode CMap for a given subset. See Adobe _PDF_Reference (ISBN 0-201-75839-3) for more information.""" cmap = [ "/CIDInit /ProcSet findresource begin", "12 dict begin", "begincmap", "/CIDSystemInfo", "<< /Registry (%s)" % fontname, "/Ordering (%s)" % fontname, "/Supplement 0", ">> def", "/CMapName /%s def" % fontname, "/CMapType 2 def", "1 begincodespacerange", "<00> <%02X>" % (len(subset) - 1), "endcodespacerange", "%d beginbfchar" % len(subset) ] + map(lambda n, subset=subset: "<%02X> <%04X>" % (n, subset[n]), range(len(subset))) + [ "endbfchar", "endcmap", "CMapName currentdict /CMap defineresource pop", "end", "end" ] return string.join(cmap, "\n") def splice(stream, offset, value): """Splices the given value into stream at the given offset and returns the resulting stream (the original is unchanged)""" return stream[:offset] + value + stream[offset + len(value):] def _set_ushort(stream, offset, value): """Writes the given unsigned short value into stream at the given offset and returns the resulting stream (the original is unchanged)""" return splice(stream, offset, pack(">H", value)) import sys try: import _rl_accel except ImportError: try: from reportlab.lib import _rl_accel except ImportError: _rl_accel = None try: hex32 = _rl_accel.hex32 except: def hex32(i): return '0X%8.8X' % (long(i)&0xFFFFFFFFL) try: add32 = _rl_accel.add32 except: if sys.hexversion>=0x02030000: def add32(x, y): "Calculate (x + y) modulo 2**32" return _L2U32((long(x)+y) & 0xffffffffL) else: def add32(x, y): "Calculate (x + y) modulo 2**32" lo = (x & 0xFFFF) + (y & 0xFFFF) hi = (x >> 16) + (y >> 16) + (lo >> 16) return (hi << 16) | (lo & 0xFFFF) try: calcChecksum = _rl_accel.calcChecksum except: def calcChecksum(data): """Calculates PDF-style checksums""" if len(data)&3: data = data + (4-(len(data)&3))*"\0" sum = 0 for n in unpack(">%dl" % (len(data)>>2), data): sum = add32(sum,n) return sum del _rl_accel, sys # # TrueType font handling # GF_ARG_1_AND_2_ARE_WORDS = 1 << 0 GF_ARGS_ARE_XY_VALUES = 1 << 1 GF_ROUND_XY_TO_GRID = 1 << 2 GF_WE_HAVE_A_SCALE = 1 << 3 GF_RESERVED = 1 << 4 GF_MORE_COMPONENTS = 1 << 5 GF_WE_HAVE_AN_X_AND_Y_SCALE = 1 << 6 GF_WE_HAVE_A_TWO_BY_TWO = 1 << 7 GF_WE_HAVE_INSTRUCTIONS = 1 << 8 GF_USE_MY_METRICS = 1 << 9 GF_OVERLAP_COMPOUND = 1 << 10 GF_SCALED_COMPONENT_OFFSET = 1 << 11 GF_UNSCALED_COMPONENT_OFFSET = 1 << 12 def TTFOpenFile(fn): '''Opens a TTF file possibly after searching TTFSearchPath returns (filename,file) ''' from reportlab.lib.utils import rl_isfile, open_for_read try: f = open_for_read(fn,'rb') return fn, f except IOError: import os if not os.path.isabs(fn): from reportlab import rl_config for D in rl_config.TTFSearchPath: tfn = os.path.join(D,fn) if rl_isfile(tfn): f = open_for_read(tfn,'rb') return tfn, f raise TTFError('Can\'t open file "%s"' % fn) class TTFontParser: "Basic TTF file parser" def __init__(self, file, validate=0): """Loads and parses a TrueType font file. file can be a filename or a file object. If validate is set to a false values, skips checksum validation. This can save time, especially if the font is large. """ # Open the file if type(file) is StringType: self.filename, file = TTFOpenFile(file) else: self.filename = '(ttf)' self._ttf_data = file.read() self._pos = 0 # Read header try: version = self.read_ulong() if version == 0x4F54544F: raise TTFError, 'OpenType fonts with PostScript outlines are not supported' if version != 0x00010000 and version != 0x74727565: raise TTFError, 'Not a TrueType font' except: raise TTFError, 'Not a TrueType font' try: self.numTables = self.read_ushort() self.searchRange = self.read_ushort() self.entrySelector = self.read_ushort() self.rangeShift = self.read_ushort() # Read table directory self.table = {} self.tables = [] for n in range(self.numTables): record = {} record['tag'] = self.read_tag() record['checksum'] = self.read_ulong() record['offset'] = self.read_ulong() record['length'] = self.read_ulong() self.tables.append(record) self.table[record['tag']] = record except: raise TTFError, 'Corrupt TrueType font file' if not validate: return # Check the checksums for the whole file checkSum = calcChecksum(self._ttf_data) if add32(_L2U32(0xB1B0AFBAL), -checkSum) != 0: raise TTFError, 'Invalid checksum %s len: %d &3: %d' % (hex32(checkSum),len(self._ttf_data),(len(self._ttf_data)&3)) # Check the checksums for all tables for t in self.tables: table = self.get_chunk(t['offset'], t['length']) checkSum = calcChecksum(table) if t['tag'] == 'head': adjustment = unpack('>l', table[8:8+4])[0] checkSum = add32(checkSum, -adjustment) if t['checksum'] != checkSum: raise TTFError, 'Invalid checksum %s table: %s' % (hex32(checkSum),t['tag']) def get_table_pos(self, tag): "Returns the offset and size of a given TTF table." offset = self.table[tag]['offset'] length = self.table[tag]['length'] return (offset, length) def seek(self, pos): "Moves read pointer to a given offset in file." self._pos = pos def skip(self, delta): "Skip the given number of bytes." self._pos = self._pos + delta def seek_table(self, tag, offset_in_table = 0): """Moves read pointer to the given offset within a given table and returns absolute offset of that position in the file.""" self._pos = self.get_table_pos(tag)[0] + offset_in_table return self._pos def read_tag(self): "Read a 4-character tag" self._pos = self._pos + 4 return self._ttf_data[self._pos - 4:self._pos] def read_ushort(self): "Reads an unsigned short" self._pos = self._pos + 2 return (ord(self._ttf_data[self._pos - 2]) << 8) + \ (ord(self._ttf_data[self._pos - 1])) def read_ulong(self): "Reads an unsigned long" self._pos = self._pos + 4 return unpack('>l',self._ttf_data[self._pos - 4:self._pos])[0] def read_short(self): "Reads a signed short" us = self.read_ushort() if us >= 0x8000: return us - 0x10000 else: return us def get_ushort(self, pos): "Return an unsigned short at given position" return (ord(self._ttf_data[pos]) << 8) + \ (ord(self._ttf_data[pos + 1])) def get_ulong(self, pos): "Return an unsigned long at given position" return unpack('>l',self._ttf_data[pos:pos+4])[0] def get_chunk(self, pos, length): "Return a chunk of raw data at given position" return self._ttf_data[pos:pos+length] def get_table(self, tag): "Return the given TTF table" pos, length = self.get_table_pos(tag) return self._ttf_data[pos:pos+length] class TTFontMaker: "Basic TTF file generator" def __init__(self): "Initializes the generator." self.tables = {} def add(self, tag, data): "Adds a table to the TTF file." if tag == 'head': data = splice(data, 8, '\0\0\0\0') self.tables[tag] = data def makeStream(self): "Finishes the generation and returns the TTF file as a string" stm = StringIO() numTables = len(self.tables) searchRange = 1 entrySelector = 0 while searchRange * 2 <= numTables: searchRange = searchRange * 2 entrySelector = entrySelector + 1 searchRange = searchRange * 16 rangeShift = numTables * 16 - searchRange # Header stm.write(pack(">lHHHH", 0x00010000, numTables, searchRange, entrySelector, rangeShift)) # Table directory tables = self.tables.items() tables.sort() # XXX is this the correct order? offset = 12 + numTables * 16 for tag, data in tables: if tag == 'head': head_start = offset checksum = calcChecksum(data) stm.write(tag) stm.write(pack(">LLL", checksum, offset, len(data))) paddedLength = (len(data)+3)&~3 offset = offset + paddedLength # Table data for tag, data in tables: data = data + "\0\0\0" stm.write(data[:len(data)&~3]) checksum = calcChecksum(stm.getvalue()) checksum = add32(_L2U32(0xB1B0AFBAL), -checksum) stm.seek(head_start + 8) stm.write(pack('>L', checksum)) return stm.getvalue() class TTFontFile(TTFontParser): "TTF file parser and generator" def __init__(self, file, charInfo=1, validate=0): """Loads and parses a TrueType font file. file can be a filename or a file object. If validate is set to a false values, skips checksum validation. This can save time, especially if the font is large. See TTFontFile.extractInfo for more information. """ TTFontParser.__init__(self, file, validate=validate) self.extractInfo(charInfo) def extractInfo(self, charInfo=1): """Extract typographic information from the loaded font file. The following attributes will be set: name - PostScript font name flags - Font flags ascent - Typographic ascender in 1/1000ths of a point descent - Typographic descender in 1/1000ths of a point capHeight - Cap height in 1/1000ths of a point (0 if not available) bbox - Glyph bounding box [l,t,r,b] in 1/1000ths of a point italicAngle - Italic angle in degrees ccw stemV - stem weight in 1/1000ths of a point (approximate) If charInfo is true, the following will also be set: defaultWidth - default glyph width in 1/1000ths of a point charWidths - dictionary of character widths for every supported UCS character code This will only work if the font has a Unicode cmap (platform 3, encoding 1, format 4 or platform 0 any encoding format 4). Setting charInfo to false avoids this requirement. """ # name - Naming table name_offset = self.seek_table("name") format = self.read_ushort() if format != 0: raise TTFError, "Unknown name table format (%d)" % format numRecords = self.read_ushort() string_data_offset = name_offset + self.read_ushort() names = {1:None,2:None,3:None,4:None,6:None} K = names.keys() nameCount = len(names) for i in range(numRecords): platformId = self.read_ushort() encodingId = self.read_ushort() languageId = self.read_ushort() nameId = self.read_ushort() length = self.read_ushort() offset = self.read_ushort() if nameId not in K: continue N = None if platformId == 3 and encodingId == 1 and languageId == 0x409: # Microsoft, Unicode, US English, PS Name self.seek(string_data_offset + offset) if length % 2 != 0: raise TTFError, "PostScript name is UTF-16BE string of odd length" length /= 2 N = [] A = N.append while length > 0: char = self.read_ushort() A(chr(char)) length -= 1 N = ''.join(N) elif platformId == 1 and encodingId == 0 and languageId == 0: # Macintosh, Roman, English, PS Name # According to OpenType spec, if PS name exists, it must exist # both in MS Unicode and Macintosh Roman formats. Apparently, # you can find live TTF fonts which only have Macintosh format. N = self.get_chunk(string_data_offset + offset, length) if N and names[nameId]==None: names[nameId] = N nameCount -= 1 if nameCount==0: break psName = names[6] if not psName: raise TTFError, "Could not find PostScript font name" for c in psName: oc = ord(c) if oc<33 or oc>126 or c in ('[', ']', '(', ')', '{', '}', '<', '>', '/', '%'): raise TTFError, "psName contains invalid character '%s' ie U+%04X" % (c,ord(c)) self.name = psName self.familyName = names[1] or psName self.styleName = names[2] or 'Regular' self.fullName = names[4] or psName self.uniqueFontID = names[3] or psName # head - Font header table self.seek_table("head") ver_maj, ver_min = self.read_ushort(), self.read_ushort() if ver_maj != 1: raise TTFError, 'Unknown head table version %d.%04x' % (ver_maj, ver_min) self.skip(8) magic = self.read_ulong() if magic != 0x5F0F3CF5: raise TTFError, 'Invalid head table magic %04x' % magic self.skip(2) unitsPerEm = self.read_ushort() scale = lambda x, unitsPerEm=unitsPerEm: x * 1000 / unitsPerEm self.skip(16) xMin = self.read_short() yMin = self.read_short() xMax = self.read_short() yMax = self.read_short() self.bbox = map(scale, [xMin, yMin, xMax, yMax]) self.skip(3*2) indexToLocFormat = self.read_ushort() glyphDataFormat = self.read_ushort() # OS/2 - OS/2 and Windows metrics table # (needs data from head table) if self.table.has_key("OS/2"): self.seek_table("OS/2") version = self.read_ushort() self.skip(2) usWeightClass = self.read_ushort() self.skip(2) fsType = self.read_ushort() if fsType == 0x0002 or (fsType & 0x0300) != 0: raise TTFError, 'Font does not allow subsetting/embedding (%04X)' % fsType self.skip(11*2 + 10 + 4*4 + 4 + 3*2) sTypoAscender = self.read_short() sTypoDescender = self.read_short() self.ascent = scale(sTypoAscender) # XXX: for some reason it needs to be multiplied by 1.24--1.28 self.descent = scale(sTypoDescender) if version > 1: self.skip(3*2 + 2*4 + 2) sCapHeight = self.read_short() self.capHeight = scale(sCapHeight) else: self.capHeight = self.ascent else: # Microsoft TTFs require an OS/2 table; Apple ones do not. Try to # cope. The data is not very important anyway. usWeightClass = 500 self.ascent = scale(yMax) self.descent = scale(yMin) self.capHeight = self.ascent # There's no way to get stemV from a TTF file short of analyzing actual outline data # This fuzzy formula is taken from pdflib sources, but we could just use 0 here self.stemV = 50 + int((usWeightClass / 65.0) ** 2) # post - PostScript table # (needs data from OS/2 table) self.seek_table("post") ver_maj, ver_min = self.read_ushort(), self.read_ushort() if ver_maj not in (1, 2, 3, 4): # Adobe/MS documents 1, 2, 2.5, 3; Apple also has 4. # From Apple docs it seems that we do not need to care # about the exact version, so if you get this error, you can # try to remove this check altogether. raise TTFError, 'Unknown post table version %d.%04x' % (ver_maj, ver_min) self.italicAngle = self.read_short() + self.read_ushort() / 65536.0 self.skip(2*2) isFixedPitch = self.read_ulong() self.flags = FF_SYMBOLIC # All fonts that contain characters # outside the original Adobe character # set are considered "symbolic". if self.italicAngle != 0: self.flags = self.flags | FF_ITALIC if usWeightClass >= 600: # FW_REGULAR == 500, FW_SEMIBOLD == 600 self.flags = self.flags | FF_FORCEBOLD if isFixedPitch: self.flags = self.flags | FF_FIXED # XXX: FF_SERIF? FF_SCRIPT? FF_ALLCAP? FF_SMALLCAP? # hhea - Horizontal header table self.seek_table("hhea") ver_maj, ver_min = self.read_ushort(), self.read_ushort() if ver_maj != 1: raise TTFError, 'Unknown hhea table version %d.%04x' % (ver_maj, ver_min) self.skip(28) metricDataFormat = self.read_ushort() if metricDataFormat != 0: raise TTFError, 'Unknown horizontal metric data format (%d)' % metricDataFormat numberOfHMetrics = self.read_ushort() if numberOfHMetrics == 0: raise TTFError, 'Number of horizontal metrics is 0' # maxp - Maximum profile table self.seek_table("maxp") ver_maj, ver_min = self.read_ushort(), self.read_ushort() if ver_maj != 1: raise TTFError, 'Unknown maxp table version %d.%04x' % (ver_maj, ver_min) numGlyphs = self.read_ushort() if not charInfo: self.charToGlyph = None self.defaultWidth = None self.charWidths = None return if glyphDataFormat != 0: raise TTFError, 'Unknown glyph data format (%d)' % glyphDataFormat # cmap - Character to glyph index mapping table cmap_offset = self.seek_table("cmap") self.skip(2) cmapTableCount = self.read_ushort() unicode_cmap_offset = None for n in range(cmapTableCount): platformID = self.read_ushort() encodingID = self.read_ushort() offset = self.read_ulong() if platformID == 3 and encodingID == 1: # Microsoft, Unicode format = self.get_ushort(cmap_offset + offset) if format == 4: unicode_cmap_offset = cmap_offset + offset break elif platformID == 0: # Unicode -- assume all encodings are compatible format = self.get_ushort(cmap_offset + offset) if format == 4: unicode_cmap_offset = cmap_offset + offset break if unicode_cmap_offset is None: raise TTFError, 'Font does not have cmap for Unicode (platform 3, encoding 1, format 4 or platform 0 any encoding format 4)' self.seek(unicode_cmap_offset + 2) length = self.read_ushort() limit = unicode_cmap_offset + length self.skip(2) segCount = self.read_ushort() / 2 self.skip(6) endCount = map(lambda x, self=self: self.read_ushort(), range(segCount)) self.skip(2) startCount = map(lambda x, self=self: self.read_ushort(), range(segCount)) idDelta = map(lambda x, self=self: self.read_short(), range(segCount)) idRangeOffset_start = self._pos idRangeOffset = map(lambda x, self=self: self.read_ushort(), range(segCount)) # Now it gets tricky. glyphToChar = {} charToGlyph = {} for n in range(segCount): for unichar in range(startCount[n], endCount[n] + 1): if idRangeOffset[n] == 0: glyph = (unichar + idDelta[n]) & 0xFFFF else: offset = (unichar - startCount[n]) * 2 + idRangeOffset[n] offset = idRangeOffset_start + 2 * n + offset if offset >= limit: # workaround for broken fonts (like Thryomanes) glyph = 0 else: glyph = self.get_ushort(offset) if glyph != 0: glyph = (glyph + idDelta[n]) & 0xFFFF charToGlyph[unichar] = glyph if glyphToChar.has_key(glyph): glyphToChar[glyph].append(unichar) else: glyphToChar[glyph] = [unichar] self.charToGlyph = charToGlyph # hmtx - Horizontal metrics table # (needs data from hhea, maxp, and cmap tables) self.seek_table("hmtx") aw = None self.charWidths = {} self.hmetrics = [] for glyph in range(numberOfHMetrics): # advance width and left side bearing. lsb is actually signed # short, but we don't need it anyway (except for subsetting) aw, lsb = self.read_ushort(), self.read_ushort() self.hmetrics.append((aw, lsb)) aw = scale(aw) if glyph == 0: self.defaultWidth = aw if glyphToChar.has_key(glyph): for char in glyphToChar[glyph]: self.charWidths[char] = aw for glyph in range(numberOfHMetrics, numGlyphs): # the rest of the table only lists advance left side bearings. # so we reuse aw set by the last iteration of the previous loop lsb = self.read_ushort() self.hmetrics.append((aw, lsb)) if glyphToChar.has_key(glyph): for char in glyphToChar[glyph]: self.charWidths[char] = aw # loca - Index to location self.seek_table('loca') self.glyphPos = [] if indexToLocFormat == 0: for n in range(numGlyphs + 1): self.glyphPos.append(self.read_ushort() << 1) elif indexToLocFormat == 1: for n in range(numGlyphs + 1): self.glyphPos.append(self.read_ulong()) else: raise TTFError, 'Unknown location table format (%d)' % indexToLocFormat # Subsetting def makeSubset(self, subset): """Create a subset of a TrueType font""" output = TTFontMaker() # Build a mapping of glyphs in the subset to glyph numbers in # the original font. Also build a mapping of UCS codes to # glyph values in the new font. # Start with 0 -> 0: "missing character" glyphMap = [0] # new glyph index -> old glyph index glyphSet = {0:0} # old glyph index -> new glyph index codeToGlyph = {} # unicode -> new glyph index for code in subset: if self.charToGlyph.has_key(code): originalGlyphIdx = self.charToGlyph[code] else: originalGlyphIdx = 0 if not glyphSet.has_key(originalGlyphIdx): glyphSet[originalGlyphIdx] = len(glyphMap) glyphMap.append(originalGlyphIdx) codeToGlyph[code] = glyphSet[originalGlyphIdx] # Also include glyphs that are parts of composite glyphs start = self.get_table_pos('glyf')[0] n = 0 while n < len(glyphMap): originalGlyphIdx = glyphMap[n] glyphPos = self.glyphPos[originalGlyphIdx] glyphLen = self.glyphPos[originalGlyphIdx + 1] - glyphPos self.seek(start + glyphPos) numberOfContours = self.read_short() if numberOfContours < 0: # composite glyph self.skip(8) flags = GF_MORE_COMPONENTS while flags & GF_MORE_COMPONENTS: flags = self.read_ushort() glyphIdx = self.read_ushort() if not glyphSet.has_key(glyphIdx): glyphSet[glyphIdx] = len(glyphMap) glyphMap.append(glyphIdx) if flags & GF_ARG_1_AND_2_ARE_WORDS: self.skip(4) else: self.skip(2) if flags & GF_WE_HAVE_A_SCALE: self.skip(2) elif flags & GF_WE_HAVE_AN_X_AND_Y_SCALE: self.skip(4) elif flags & GF_WE_HAVE_A_TWO_BY_TWO: self.skip(8) n = n + 1 numGlyphs = n = len(glyphMap) while n > 1 and self.hmetrics[n][0] == self.hmetrics[n - 1][0]: n = n - 1 numberOfHMetrics = n # The following tables are simply copied from the original for tag in ('name', 'OS/2', 'cvt ', 'fpgm', 'prep'): try: output.add(tag, self.get_table(tag)) except KeyError: # Apparently some of the tables are optional (cvt, fpgm, prep). # The lack of the required ones (name, OS/2) would have already # been caught before. pass # post - PostScript post = "\x00\x03\x00\x00" + self.get_table('post')[4:16] + "\x00" * 16 output.add('post', post) # hhea - Horizontal Header hhea = self.get_table('hhea') hhea = _set_ushort(hhea, 34, numberOfHMetrics) output.add('hhea', hhea) # maxp - Maximum Profile maxp = self.get_table('maxp') maxp = _set_ushort(maxp, 4, numGlyphs) output.add('maxp', maxp) # cmap - Character to glyph mapping # XXX maybe use format 0 if possible, not 6? entryCount = len(subset) length = 10 + entryCount * 2 cmap = [0, 1, # version, number of tables 1, 0, 0,12, # platform, encoding, offset (hi,lo) 6, length, 0, # format, length, language 0, entryCount] + \ map(codeToGlyph.get, subset) cmap = apply(pack, [">%dH" % len(cmap)] + cmap) output.add('cmap', cmap) # hmtx - Horizontal Metrics hmtx = [] for n in range(numGlyphs): originalGlyphIdx = glyphMap[n] aw, lsb = self.hmetrics[originalGlyphIdx] if n < numberOfHMetrics: hmtx.append(aw) hmtx.append(lsb) hmtx = apply(pack, [">%dH" % len(hmtx)] + hmtx) output.add('hmtx', hmtx) # glyf - Glyph data glyphData = self.get_table('glyf') offsets = [] glyf = [] pos = 0 for n in range(numGlyphs): offsets.append(pos) originalGlyphIdx = glyphMap[n] glyphPos = self.glyphPos[originalGlyphIdx] glyphLen = self.glyphPos[originalGlyphIdx + 1] - glyphPos data = glyphData[glyphPos:glyphPos+glyphLen] # Fix references in composite glyphs if glyphLen > 2 and unpack(">h", data[:2])[0] < 0: # composite glyph pos_in_glyph = 10 flags = GF_MORE_COMPONENTS while flags & GF_MORE_COMPONENTS: flags = unpack(">H", data[pos_in_glyph:pos_in_glyph+2])[0] glyphIdx = unpack(">H", data[pos_in_glyph+2:pos_in_glyph+4])[0] data = _set_ushort(data, pos_in_glyph + 2, glyphSet[glyphIdx]) pos_in_glyph = pos_in_glyph + 4 if flags & GF_ARG_1_AND_2_ARE_WORDS: pos_in_glyph = pos_in_glyph + 4 else: pos_in_glyph = pos_in_glyph + 2 if flags & GF_WE_HAVE_A_SCALE: pos_in_glyph = pos_in_glyph + 2 elif flags & GF_WE_HAVE_AN_X_AND_Y_SCALE: pos_in_glyph = pos_in_glyph + 4 elif flags & GF_WE_HAVE_A_TWO_BY_TWO: pos_in_glyph = pos_in_glyph + 8 glyf.append(data) pos = pos + glyphLen if pos % 4 != 0: padding = 4 - pos % 4 glyf.append('\0' * padding) pos = pos + padding offsets.append(pos) output.add('glyf', string.join(glyf, "")) # loca - Index to location loca = [] if (pos + 1) >> 1 > 0xFFFF: indexToLocFormat = 1 # long format for offset in offsets: loca.append(offset) loca = apply(pack, [">%dL" % len(loca)] + loca) else: indexToLocFormat = 0 # short format for offset in offsets: loca.append(offset >> 1) loca = apply(pack, [">%dH" % len(loca)] + loca) output.add('loca', loca) # head - Font header head = self.get_table('head') head = _set_ushort(head, 50, indexToLocFormat) output.add('head', head) return output.makeStream() # # TrueType font embedding # # PDF font flags (see PDF Reference Guide table 5.19) FF_FIXED = 1 << 1-1 FF_SERIF = 1 << 2-1 FF_SYMBOLIC = 1 << 3-1 FF_SCRIPT = 1 << 4-1 FF_NONSYMBOLIC = 1 << 6-1 FF_ITALIC = 1 << 7-1 FF_ALLCAP = 1 << 17-1 FF_SMALLCAP = 1 << 18-1 FF_FORCEBOLD = 1 << 19-1 class TTFontFace(TTFontFile, pdfmetrics.TypeFace): """TrueType typeface. Conceptually similar to a single byte typeface, but the glyphs are identified by UCS character codes instead of glyph names.""" def __init__(self, filename, validate=0): "Loads a TrueType font from filename." pdfmetrics.TypeFace.__init__(self, None) TTFontFile.__init__(self, filename, validate=validate) def getCharWidth(self, code): "Returns the width of character U+" return self.charWidths.get(code, self.defaultWidth) def addSubsetObjects(self, doc, fontname, subset): """Generate a TrueType font subset and add it to the PDF document. Returns a PDFReference to the new FontDescriptor object.""" fontFile = pdfdoc.PDFStream() fontFile.content = self.makeSubset(subset) fontFile.dictionary['Length1'] = len(fontFile.content) if doc.compression: fontFile.filters = [pdfdoc.PDFZCompress] fontFileRef = doc.Reference(fontFile, 'fontFile:%s(%s)' % (self.filename, fontname)) flags = self.flags & ~ FF_NONSYMBOLIC flags = flags | FF_SYMBOLIC fontDescriptor = pdfdoc.PDFDictionary({ 'Type': '/FontDescriptor', 'Ascent': self.ascent, 'CapHeight': self.capHeight, 'Descent': self.descent, 'Flags': flags, 'FontBBox': pdfdoc.PDFArray(self.bbox), 'FontName': pdfdoc.PDFName(fontname), 'ItalicAngle': self.italicAngle, 'StemV': self.stemV, 'FontFile2': fontFileRef, }) return doc.Reference(fontDescriptor, 'fontDescriptor:' + fontname) class TTEncoding: """Encoding for TrueType fonts (always UTF-8). TTEncoding does not directly participate in PDF object creation, since we need a number of different 8-bit encodings for every generated font subset. TTFont itself cares about that.""" def __init__(self): self.name = "UTF-8" class TTFont: """Represents a TrueType font. Its encoding is always UTF-8. Note: you cannot use the same TTFont object for different documents at the same time. Example of usage: font = ttfonts.TTFont('PostScriptFontName', '/path/to/font.ttf') pdfmetrics.registerFont(font) canvas.setFont('PostScriptFontName', size) canvas.drawString(x, y, "Some text encoded in UTF-8") """ class State: def __init__(self): self.assignments = {} self.nextCode = 0 self.subsets = [] self.internalName = None self.frozen = 0 def __init__(self, name, filename, validate=0): """Loads a TrueType font from filename. If validate is set to a false values, skips checksum validation. This can save time, especially if the font is large. """ self.fontName = name self.face = TTFontFace(filename, validate=validate) self.encoding = TTEncoding() self._multiByte = 1 # We want our own stringwidth self._dynamicFont = 1 # We want dynamic subsetting self.state = {} def stringWidth(self, text, size): "Calculate text width" width = self.face.getCharWidth w = 0 for code in parse_utf8(text): w = w + width(code) return 0.001 * w * size def splitString(self, text, doc): """Splits text into a number of chunks, each of which belongs to a single subset. Returns a list of tuples (subset, string). Use subset numbers with getSubsetInternalName. Doc is needed for distinguishing subsets when building different documents at the same time.""" try: state = self.state[doc] except KeyError: state = self.state[doc] = TTFont.State() curSet = -1 cur = [] results = [] for code in parse_utf8(text): if state.assignments.has_key(code): n = state.assignments[code] else: if state.frozen: raise pdfdoc.PDFError, "Font %s is already frozen, cannot add new character U+%04X" % (self.fontName, code) n = state.nextCode state.nextCode = state.nextCode + 1 state.assignments[code] = n if (n & 0xFF) == 0: state.subsets.append([]) state.subsets[n >> 8].append(code) if (n >> 8) != curSet: if cur: results.append((curSet, string.join(map(chr, cur), ""))) curSet = (n >> 8) cur = [] cur.append(n & 0xFF) if cur: results.append((curSet, string.join(map(chr, cur), ""))) return results def getSubsetInternalName(self, subset, doc): """Returns the name of a PDF Font object corresponding to a given subset of this dynamic font. Use this function instead of PDFDocument.getInternalFontName.""" try: state = self.state[doc] except KeyError: state = self.state[doc] = TTFont.State() if subset < 0 or subset >= len(state.subsets): raise IndexError, 'Subset %d does not exist in font %s' % (subset, self.fontName) if state.internalName is None: state.internalName = 'F%d' % (len(doc.fontMapping) + 1) doc.fontMapping[self.fontName] = '/' + state.internalName doc.delayedFonts.append(self) return '/%s+%d' % (state.internalName, subset) def addObjects(self, doc): """Makes one or more PDF objects to be added to the document. The caller supplies the internal name to be used (typically F1, F2, ... in sequence). This method creates a number of Font and FontDescriptor objects. Every FontDescriptor is a (no more than) 256 character subset of the original TrueType font.""" try: state = self.state[doc] except KeyError: state = self.state[doc] = TTFont.State() state.frozen = 1 for n in range(len(state.subsets)): subset = state.subsets[n] internalName = self.getSubsetInternalName(n, doc)[1:] baseFontName = "SUBSET+%s+%d" % (self.face.name, n) pdfFont = pdfdoc.PDFTrueTypeFont() pdfFont.__Comment__ = 'Font %s subset %d' % (self.fontName, n) pdfFont.Name = internalName pdfFont.BaseFont = baseFontName pdfFont.FirstChar = 0 pdfFont.LastChar = len(subset) - 1 widths = map(self.face.getCharWidth, subset) pdfFont.Widths = pdfdoc.PDFArray(widths) cmapStream = pdfdoc.PDFStream() cmapStream.content = makeToUnicodeCMap(baseFontName, subset) if doc.compression: cmapStream.filters = [pdfdoc.PDFZCompress] pdfFont.ToUnicode = doc.Reference(cmapStream, 'toUnicodeCMap:' + baseFontName) pdfFont.FontDescriptor = self.face.addSubsetObjects(doc, baseFontName, subset) # link it in ref = doc.Reference(pdfFont, internalName) fontDict = doc.idToObject['BasicFonts'].dict fontDict[internalName] = pdfFont del self.state[doc]