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#

# 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