from fontTools.misc import sstruct
from fontTools.misc.textTools import readHex, safeEval
import struct
sbixGlyphHeaderFormat = """
>
originOffsetX: h # The x-value of the point in the glyph relative to its
# lower-left corner which corresponds to the origin of
# the glyph on the screen, that is the point on the
# baseline at the left edge of the glyph.
originOffsetY: h # The y-value of the point in the glyph relative to its
# lower-left corner which corresponds to the origin of
# the glyph on the screen, that is the point on the
# baseline at the left edge of the glyph.
graphicType: 4s # e.g. "png "
"""
sbixGlyphHeaderFormatSize = sstruct.calcsize(sbixGlyphHeaderFormat)
[docs]
class Glyph(object):
def __init__(
self,
glyphName=None,
referenceGlyphName=None,
originOffsetX=0,
originOffsetY=0,
graphicType=None,
imageData=None,
rawdata=None,
gid=0,
):
self.gid = gid
self.glyphName = glyphName
self.referenceGlyphName = referenceGlyphName
self.originOffsetX = originOffsetX
self.originOffsetY = originOffsetY
self.rawdata = rawdata
self.graphicType = graphicType
self.imageData = imageData
# fix self.graphicType if it is null terminated or too short
if self.graphicType is not None:
if self.graphicType[-1] == "\0":
self.graphicType = self.graphicType[:-1]
if len(self.graphicType) > 4:
from fontTools import ttLib
raise ttLib.TTLibError(
"Glyph.graphicType must not be longer than 4 characters."
)
elif len(self.graphicType) < 4:
# pad with spaces
self.graphicType += " "[: (4 - len(self.graphicType))]
[docs]
def is_reference_type(self):
"""Returns True if this glyph is a reference to another glyph's image data."""
return self.graphicType == "dupe" or self.graphicType == "flip"
[docs]
def decompile(self, ttFont):
self.glyphName = ttFont.getGlyphName(self.gid)
if self.rawdata is None:
from fontTools import ttLib
raise ttLib.TTLibError("No table data to decompile")
if len(self.rawdata) > 0:
if len(self.rawdata) < sbixGlyphHeaderFormatSize:
from fontTools import ttLib
# print "Glyph %i header too short: Expected %x, got %x." % (self.gid, sbixGlyphHeaderFormatSize, len(self.rawdata))
raise ttLib.TTLibError("Glyph header too short.")
sstruct.unpack(
sbixGlyphHeaderFormat, self.rawdata[:sbixGlyphHeaderFormatSize], self
)
if self.is_reference_type():
# this glyph is a reference to another glyph's image data
(gid,) = struct.unpack(">H", self.rawdata[sbixGlyphHeaderFormatSize:])
self.referenceGlyphName = ttFont.getGlyphName(gid)
else:
self.imageData = self.rawdata[sbixGlyphHeaderFormatSize:]
self.referenceGlyphName = None
# clean up
del self.rawdata
del self.gid
[docs]
def compile(self, ttFont):
if self.glyphName is None:
from fontTools import ttLib
raise ttLib.TTLibError("Can't compile Glyph without glyph name")
# TODO: if ttFont has no maxp, cmap etc., ignore glyph names and compile by index?
# (needed if you just want to compile the sbix table on its own)
self.gid = struct.pack(">H", ttFont.getGlyphID(self.glyphName))
if self.graphicType is None:
rawdata = b""
else:
rawdata = sstruct.pack(sbixGlyphHeaderFormat, self)
if self.is_reference_type():
rawdata += struct.pack(">H", ttFont.getGlyphID(self.referenceGlyphName))
else:
assert self.imageData is not None
rawdata += self.imageData
self.rawdata = rawdata
[docs]
def toXML(self, xmlWriter, ttFont):
if self.graphicType is None:
# TODO: ignore empty glyphs?
# a glyph data entry is required for each glyph,
# but empty ones can be calculated at compile time
xmlWriter.simpletag("glyph", name=self.glyphName)
xmlWriter.newline()
return
xmlWriter.begintag(
"glyph",
graphicType=self.graphicType,
name=self.glyphName,
originOffsetX=self.originOffsetX,
originOffsetY=self.originOffsetY,
)
xmlWriter.newline()
if self.is_reference_type():
# this glyph is a reference to another glyph id.
xmlWriter.simpletag("ref", glyphname=self.referenceGlyphName)
else:
xmlWriter.begintag("hexdata")
xmlWriter.newline()
xmlWriter.dumphex(self.imageData)
xmlWriter.endtag("hexdata")
xmlWriter.newline()
xmlWriter.endtag("glyph")
xmlWriter.newline()
[docs]
def fromXML(self, name, attrs, content, ttFont):
if name == "ref":
# this glyph i.e. a reference to another glyph's image data.
# in this case imageData contains the glyph id of the reference glyph
# get glyph id from glyphname
glyphname = safeEval("'''" + attrs["glyphname"] + "'''")
self.imageData = struct.pack(">H", ttFont.getGlyphID(glyphname))
self.referenceGlyphName = glyphname
elif name == "hexdata":
self.imageData = readHex(content)
else:
from fontTools import ttLib
raise ttLib.TTLibError("can't handle '%s' element" % name)