Current File : //usr/lib/calibre/calibre/utils/fonts/sfnt/glyf.py
#!/usr/bin/env python3
__license__ = 'GPL v3'
__copyright__ = '2012, Kovid Goyal <kovid at kovidgoyal.net>'
__docformat__ = 'restructuredtext en'
from struct import unpack_from
from collections import OrderedDict
from calibre.utils.fonts.sfnt import UnknownTable
from polyglot.builtins import iteritems
ARG_1_AND_2_ARE_WORDS = 0x0001 # if set args are words otherwise they are bytes
ARGS_ARE_XY_VALUES = 0x0002 # if set args are xy values, otherwise they are points
ROUND_XY_TO_GRID = 0x0004 # for the xy values if above is true
WE_HAVE_A_SCALE = 0x0008 # Sx = Sy, otherwise scale == 1.0
NON_OVERLAPPING = 0x0010 # set to same value for all components (obsolete!)
MORE_COMPONENTS = 0x0020 # indicates at least one more glyph after this one
WE_HAVE_AN_X_AND_Y_SCALE = 0x0040 # Sx, Sy
WE_HAVE_A_TWO_BY_TWO = 0x0080 # t00, t01, t10, t11
WE_HAVE_INSTRUCTIONS = 0x0100 # instructions follow
USE_MY_METRICS = 0x0200 # apply these metrics to parent glyph
OVERLAP_COMPOUND = 0x0400 # used by Apple in GX fonts
SCALED_COMPONENT_OFFSET = 0x0800 # composite designed to have the component offset scaled (designed for Apple)
UNSCALED_COMPONENT_OFFSET = 0x1000 # composite designed not to have the component offset scaled (designed for MS)
class SimpleGlyph:
def __init__(self, num_of_countours, raw):
self.num_of_countours = num_of_countours
self.raw = raw
# The list of glyph indices referred to by this glyph, will always be
# empty for a simple glyph and not empty for a composite glyph
self.glyph_indices = []
self.is_composite = False
def __len__(self):
return len(self.raw)
def __call__(self):
return self.raw
class CompositeGlyph(SimpleGlyph):
def __init__(self, num_of_countours, raw):
super().__init__(num_of_countours, raw)
self.is_composite = True
flags = MORE_COMPONENTS
offset = 10
while flags & MORE_COMPONENTS:
flags, glyph_index = unpack_from(b'>HH', raw, offset)
self.glyph_indices.append(glyph_index)
offset += 4
if flags & ARG_1_AND_2_ARE_WORDS:
offset += 4
else:
offset += 2
if flags & WE_HAVE_A_SCALE:
offset += 2
elif flags & WE_HAVE_AN_X_AND_Y_SCALE:
offset += 4
elif flags & WE_HAVE_A_TWO_BY_TWO:
offset += 8
class GlyfTable(UnknownTable):
def glyph_data(self, offset, length, as_raw=False):
raw = self.raw[offset:offset+length]
if as_raw:
return raw
num_of_countours = unpack_from(b'>h', raw)[0] if raw else 0
if num_of_countours >= 0:
return SimpleGlyph(num_of_countours, raw)
return CompositeGlyph(num_of_countours, raw)
def update(self, sorted_glyph_map):
ans = OrderedDict()
offset = 0
block = []
for glyph_id, glyph in iteritems(sorted_glyph_map):
raw = glyph()
pad = 4 - (len(raw) % 4)
if pad < 4:
raw += b'\0' * pad
ans[glyph_id] = offset, len(raw)
offset += len(raw)
block.append(raw)
self.raw = b''.join(block)
return ans
Mini Shell