def interpolate_cff2_metrics(varfont, topDict, glyphOrder, loc):
"""Unlike TrueType glyphs, neither advance width nor bounding box
info is stored in a CFF2 charstring. The width data exists only in
the hmtx and HVAR tables. Since LSB data cannot be interpolated
reliably from the master LSB values in the hmtx table, we traverse
the charstring to determine the actual bound box. """
charstrings = topDict.CharStrings
boundsPen = BoundsPen(glyphOrder)
hmtx = varfont['hmtx']
hvar_table = None
if 'HVAR' in varfont:
hvar_table = varfont['HVAR'].table
fvar = varfont['fvar']
varStoreInstancer = VarStoreInstancer(hvar_table.VarStore, fvar.axes,
loc)
for gid, gname in enumerate(glyphOrder):
entry = list(hmtx[gname])
# get width delta.
if hvar_table:
if hvar_table.AdvWidthMap:
width_idx = hvar_table.AdvWidthMap.mapping[gname]
else:
width_idx = gid
width_delta = otRound(varStoreInstancer[width_idx])
else:
width_delta = 0
# get LSB.
boundsPen.init()
charstring = charstrings[gname]
charstring.draw(boundsPen)
if boundsPen.bounds is None:
# Happens with non-marking glyphs
lsb_delta = 0
else:
lsb = boundsPen.bounds[0]
lsb_delta = entry[1] - lsb
if lsb_delta or width_delta:
if width_delta:
entry[0] += width_delta
if lsb_delta:
entry[1] = lsb
hmtx[gname] = tuple(entry)
def interpolate_cff2_metrics(varfont, topDict, glyphOrder, loc): """Unlike TrueType glyphs, neither advance width nor bounding box info is stored in a CFF2 charstring. The width data exists only in the hmtx and HVAR tables. Since LSB data cannot be interpolated reliably from the master LSB values in the hmtx table, we traverse the charstring to determine the actual bound box. """ charstrings = topDict.CharStrings boundsPen = BoundsPen(glyphOrder) hmtx = varfont['hmtx'] hvar_table = None if 'HVAR' in varfont: hvar_table = varfont['HVAR'].table fvar = varfont['fvar'] varStoreInstancer = VarStoreInstancer(hvar_table.VarStore, fvar.axes, loc) for gid, gname in enumerate(glyphOrder): entry = list(hmtx[gname]) # get width delta. if hvar_table: if hvar_table.AdvWidthMap: width_idx = hvar_table.AdvWidthMap.mapping[gname] else: width_idx = gid width_delta = otRound(varStoreInstancer[width_idx]) else: width_delta = 0 # get LSB. boundsPen.init() charstring = charstrings[gname] charstring.draw(boundsPen) if boundsPen.bounds is None: # Happens with non-marking glyphs lsb_delta = 0 else: lsb = boundsPen.bounds[0] lsb_delta = entry[1] - lsb if lsb_delta or width_delta: if width_delta: entry[0] += width_delta if lsb_delta: entry[1] = lsb hmtx[gname] = tuple(entry)
