You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
255 lines
7.0 KiB
255 lines
7.0 KiB
#
|
|
# THIS IS WORK IN PROGRESS
|
|
#
|
|
# The Python Imaging Library
|
|
# $Id$
|
|
#
|
|
# portable compiled font file parser
|
|
#
|
|
# history:
|
|
# 1997-08-19 fl created
|
|
# 2003-09-13 fl fixed loading of unicode fonts
|
|
#
|
|
# Copyright (c) 1997-2003 by Secret Labs AB.
|
|
# Copyright (c) 1997-2003 by Fredrik Lundh.
|
|
#
|
|
# See the README file for information on usage and redistribution.
|
|
#
|
|
from __future__ import annotations
|
|
|
|
import io
|
|
from typing import BinaryIO, Callable
|
|
|
|
from . import FontFile, Image
|
|
from ._binary import i8
|
|
from ._binary import i16be as b16
|
|
from ._binary import i16le as l16
|
|
from ._binary import i32be as b32
|
|
from ._binary import i32le as l32
|
|
|
|
# --------------------------------------------------------------------
|
|
# declarations
|
|
|
|
PCF_MAGIC = 0x70636601 # "\x01fcp"
|
|
|
|
PCF_PROPERTIES = 1 << 0
|
|
PCF_ACCELERATORS = 1 << 1
|
|
PCF_METRICS = 1 << 2
|
|
PCF_BITMAPS = 1 << 3
|
|
PCF_INK_METRICS = 1 << 4
|
|
PCF_BDF_ENCODINGS = 1 << 5
|
|
PCF_SWIDTHS = 1 << 6
|
|
PCF_GLYPH_NAMES = 1 << 7
|
|
PCF_BDF_ACCELERATORS = 1 << 8
|
|
|
|
BYTES_PER_ROW: list[Callable[[int], int]] = [
|
|
lambda bits: ((bits + 7) >> 3),
|
|
lambda bits: ((bits + 15) >> 3) & ~1,
|
|
lambda bits: ((bits + 31) >> 3) & ~3,
|
|
lambda bits: ((bits + 63) >> 3) & ~7,
|
|
]
|
|
|
|
|
|
def sz(s: bytes, o: int) -> bytes:
|
|
return s[o : s.index(b"\0", o)]
|
|
|
|
|
|
class PcfFontFile(FontFile.FontFile):
|
|
"""Font file plugin for the X11 PCF format."""
|
|
|
|
name = "name"
|
|
|
|
def __init__(self, fp: BinaryIO, charset_encoding: str = "iso8859-1"):
|
|
self.charset_encoding = charset_encoding
|
|
|
|
magic = l32(fp.read(4))
|
|
if magic != PCF_MAGIC:
|
|
msg = "not a PCF file"
|
|
raise SyntaxError(msg)
|
|
|
|
super().__init__()
|
|
|
|
count = l32(fp.read(4))
|
|
self.toc = {}
|
|
for i in range(count):
|
|
type = l32(fp.read(4))
|
|
self.toc[type] = l32(fp.read(4)), l32(fp.read(4)), l32(fp.read(4))
|
|
|
|
self.fp = fp
|
|
|
|
self.info = self._load_properties()
|
|
|
|
metrics = self._load_metrics()
|
|
bitmaps = self._load_bitmaps(metrics)
|
|
encoding = self._load_encoding()
|
|
|
|
#
|
|
# create glyph structure
|
|
|
|
for ch, ix in enumerate(encoding):
|
|
if ix is not None:
|
|
(
|
|
xsize,
|
|
ysize,
|
|
left,
|
|
right,
|
|
width,
|
|
ascent,
|
|
descent,
|
|
attributes,
|
|
) = metrics[ix]
|
|
self.glyph[ch] = (
|
|
(width, 0),
|
|
(left, descent - ysize, xsize + left, descent),
|
|
(0, 0, xsize, ysize),
|
|
bitmaps[ix],
|
|
)
|
|
|
|
def _getformat(
|
|
self, tag: int
|
|
) -> tuple[BinaryIO, int, Callable[[bytes], int], Callable[[bytes], int]]:
|
|
format, size, offset = self.toc[tag]
|
|
|
|
fp = self.fp
|
|
fp.seek(offset)
|
|
|
|
format = l32(fp.read(4))
|
|
|
|
if format & 4:
|
|
i16, i32 = b16, b32
|
|
else:
|
|
i16, i32 = l16, l32
|
|
|
|
return fp, format, i16, i32
|
|
|
|
def _load_properties(self) -> dict[bytes, bytes | int]:
|
|
#
|
|
# font properties
|
|
|
|
properties = {}
|
|
|
|
fp, format, i16, i32 = self._getformat(PCF_PROPERTIES)
|
|
|
|
nprops = i32(fp.read(4))
|
|
|
|
# read property description
|
|
p = [(i32(fp.read(4)), i8(fp.read(1)), i32(fp.read(4))) for _ in range(nprops)]
|
|
|
|
if nprops & 3:
|
|
fp.seek(4 - (nprops & 3), io.SEEK_CUR) # pad
|
|
|
|
data = fp.read(i32(fp.read(4)))
|
|
|
|
for k, s, v in p:
|
|
property_value: bytes | int = sz(data, v) if s else v
|
|
properties[sz(data, k)] = property_value
|
|
|
|
return properties
|
|
|
|
def _load_metrics(self) -> list[tuple[int, int, int, int, int, int, int, int]]:
|
|
#
|
|
# font metrics
|
|
|
|
metrics: list[tuple[int, int, int, int, int, int, int, int]] = []
|
|
|
|
fp, format, i16, i32 = self._getformat(PCF_METRICS)
|
|
|
|
append = metrics.append
|
|
|
|
if (format & 0xFF00) == 0x100:
|
|
# "compressed" metrics
|
|
for i in range(i16(fp.read(2))):
|
|
left = i8(fp.read(1)) - 128
|
|
right = i8(fp.read(1)) - 128
|
|
width = i8(fp.read(1)) - 128
|
|
ascent = i8(fp.read(1)) - 128
|
|
descent = i8(fp.read(1)) - 128
|
|
xsize = right - left
|
|
ysize = ascent + descent
|
|
append((xsize, ysize, left, right, width, ascent, descent, 0))
|
|
|
|
else:
|
|
# "jumbo" metrics
|
|
for i in range(i32(fp.read(4))):
|
|
left = i16(fp.read(2))
|
|
right = i16(fp.read(2))
|
|
width = i16(fp.read(2))
|
|
ascent = i16(fp.read(2))
|
|
descent = i16(fp.read(2))
|
|
attributes = i16(fp.read(2))
|
|
xsize = right - left
|
|
ysize = ascent + descent
|
|
append((xsize, ysize, left, right, width, ascent, descent, attributes))
|
|
|
|
return metrics
|
|
|
|
def _load_bitmaps(
|
|
self, metrics: list[tuple[int, int, int, int, int, int, int, int]]
|
|
) -> list[Image.Image]:
|
|
#
|
|
# bitmap data
|
|
|
|
fp, format, i16, i32 = self._getformat(PCF_BITMAPS)
|
|
|
|
nbitmaps = i32(fp.read(4))
|
|
|
|
if nbitmaps != len(metrics):
|
|
msg = "Wrong number of bitmaps"
|
|
raise OSError(msg)
|
|
|
|
offsets = [i32(fp.read(4)) for _ in range(nbitmaps)]
|
|
|
|
bitmap_sizes = [i32(fp.read(4)) for _ in range(4)]
|
|
|
|
# byteorder = format & 4 # non-zero => MSB
|
|
bitorder = format & 8 # non-zero => MSB
|
|
padindex = format & 3
|
|
|
|
bitmapsize = bitmap_sizes[padindex]
|
|
offsets.append(bitmapsize)
|
|
|
|
data = fp.read(bitmapsize)
|
|
|
|
pad = BYTES_PER_ROW[padindex]
|
|
mode = "1;R"
|
|
if bitorder:
|
|
mode = "1"
|
|
|
|
bitmaps = []
|
|
for i in range(nbitmaps):
|
|
xsize, ysize = metrics[i][:2]
|
|
b, e = offsets[i : i + 2]
|
|
bitmaps.append(
|
|
Image.frombytes("1", (xsize, ysize), data[b:e], "raw", mode, pad(xsize))
|
|
)
|
|
|
|
return bitmaps
|
|
|
|
def _load_encoding(self) -> list[int | None]:
|
|
fp, format, i16, i32 = self._getformat(PCF_BDF_ENCODINGS)
|
|
|
|
first_col, last_col = i16(fp.read(2)), i16(fp.read(2))
|
|
first_row, last_row = i16(fp.read(2)), i16(fp.read(2))
|
|
|
|
i16(fp.read(2)) # default
|
|
|
|
nencoding = (last_col - first_col + 1) * (last_row - first_row + 1)
|
|
|
|
# map character code to bitmap index
|
|
encoding: list[int | None] = [None] * min(256, nencoding)
|
|
|
|
encoding_offsets = [i16(fp.read(2)) for _ in range(nencoding)]
|
|
|
|
for i in range(first_col, len(encoding)):
|
|
try:
|
|
encoding_offset = encoding_offsets[
|
|
ord(bytearray([i]).decode(self.charset_encoding))
|
|
]
|
|
if encoding_offset != 0xFFFF:
|
|
encoding[i] = encoding_offset
|
|
except UnicodeDecodeError:
|
|
# character is not supported in selected encoding
|
|
pass
|
|
|
|
return encoding
|