Source code for fontTools.ttLib.tables.S_V_G_

"""Compiles/decompiles SVG table.

https://docs.microsoft.com/en-us/typography/opentype/spec/svg

The XML format is:

.. code-block:: xml

	<SVG>
		<svgDoc endGlyphID="1" startGlyphID="1">
			<![CDATA[ <complete SVG doc> ]]
		</svgDoc>
	...
		<svgDoc endGlyphID="n" startGlyphID="m">
			<![CDATA[ <complete SVG doc> ]]
		</svgDoc>
	</SVG>
"""

from fontTools.misc.textTools import bytesjoin, strjoin, tobytes, tostr
from fontTools.misc import sstruct
from . import DefaultTable
from io import BytesIO
import struct
import logging


log = logging.getLogger(__name__)


SVG_format_0 = """
	>   # big endian
	version:                  H
	offsetToSVGDocIndex:      L
	reserved:                 L
"""

SVG_format_0Size = sstruct.calcsize(SVG_format_0)

doc_index_entry_format_0 = """
	>   # big endian
	startGlyphID:             H
	endGlyphID:               H
	svgDocOffset:             L
	svgDocLength:             L
"""

doc_index_entry_format_0Size = sstruct.calcsize(doc_index_entry_format_0)



[docs]class table_S_V_G_(DefaultTable.DefaultTable):
[docs] def decompile(self, data, ttFont): self.docList = [] # Version 0 is the standardized version of the table; and current. # https://www.microsoft.com/typography/otspec/svg.htm sstruct.unpack(SVG_format_0, data[:SVG_format_0Size], self) if self.version != 0: log.warning( "Unknown SVG table version '%s'. Decompiling as version 0.", self.version) # read in SVG Documents Index # data starts with the first entry of the entry list. pos = subTableStart = self.offsetToSVGDocIndex self.numEntries = struct.unpack(">H", data[pos:pos+2])[0] pos += 2 if self.numEntries > 0: data2 = data[pos:] entries = [] for i in range(self.numEntries): docIndexEntry, data2 = sstruct.unpack2(doc_index_entry_format_0, data2, DocumentIndexEntry()) entries.append(docIndexEntry) for entry in entries: start = entry.svgDocOffset + subTableStart end = start + entry.svgDocLength doc = data[start:end] if doc.startswith(b"\x1f\x8b"): import gzip bytesIO = BytesIO(doc) with gzip.GzipFile(None, "r", fileobj=bytesIO) as gunzipper: doc = gunzipper.read() self.compressed = True del bytesIO doc = tostr(doc, "utf_8") self.docList.append( [doc, entry.startGlyphID, entry.endGlyphID] )
[docs] def compile(self, ttFont): version = 0 offsetToSVGDocIndex = SVG_format_0Size # I start the SVGDocIndex right after the header. # get SGVDoc info. docList = [] entryList = [] numEntries = len(self.docList) datum = struct.pack(">H",numEntries) entryList.append(datum) curOffset = len(datum) + doc_index_entry_format_0Size*numEntries seenDocs = {} for doc, startGlyphID, endGlyphID in self.docList: docBytes = tobytes(doc, encoding="utf_8") if getattr(self, "compressed", False) and not docBytes.startswith(b"\x1f\x8b"): import gzip bytesIO = BytesIO() with gzip.GzipFile(None, "w", fileobj=bytesIO) as gzipper: gzipper.write(docBytes) gzipped = bytesIO.getvalue() if len(gzipped) < len(docBytes): docBytes = gzipped del gzipped, bytesIO docLength = len(docBytes) if docBytes in seenDocs: docOffset = seenDocs[docBytes] else: docOffset = curOffset curOffset += docLength seenDocs[docBytes] = docOffset docList.append(docBytes) entry = struct.pack(">HHLL", startGlyphID, endGlyphID, docOffset, docLength) entryList.append(entry) entryList.extend(docList) svgDocData = bytesjoin(entryList) reserved = 0 header = struct.pack(">HLL", version, offsetToSVGDocIndex, reserved) data = [header, svgDocData] data = bytesjoin(data) return data
[docs] def toXML(self, writer, ttFont): for doc, startGID, endGID in self.docList: writer.begintag("svgDoc", startGlyphID=startGID, endGlyphID=endGID) writer.newline() writer.writecdata(doc) writer.newline() writer.endtag("svgDoc") writer.newline()
[docs] def fromXML(self, name, attrs, content, ttFont): if name == "svgDoc": if not hasattr(self, "docList"): self.docList = [] doc = strjoin(content) doc = doc.strip() startGID = int(attrs["startGlyphID"]) endGID = int(attrs["endGlyphID"]) self.docList.append( [doc, startGID, endGID] ) else: log.warning("Unknown %s %s", name, content)
[docs]class DocumentIndexEntry(object): def __init__(self): self.startGlyphID = None # USHORT self.endGlyphID = None # USHORT self.svgDocOffset = None # ULONG self.svgDocLength = None # ULONG def __repr__(self): return "startGlyphID: %s, endGlyphID: %s, svgDocOffset: %s, svgDocLength: %s" % (self.startGlyphID, self.endGlyphID, self.svgDocOffset, self.svgDocLength)