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# | |
# The Python Imaging Library | |
# $Id$ | |
# | |
# bitmap distribution font (bdf) file parser | |
# | |
# history: | |
# 1996-05-16 fl created (as bdf2pil) | |
# 1997-08-25 fl converted to FontFile driver | |
# 2001-05-25 fl removed bogus __init__ call | |
# 2002-11-20 fl robustification (from Kevin Cazabon, Dmitry Vasiliev) | |
# 2003-04-22 fl more robustification (from Graham Dumpleton) | |
# | |
# 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. | |
# | |
""" | |
Parse X Bitmap Distribution Format (BDF) | |
""" | |
from __future__ import annotations | |
from typing import BinaryIO | |
from . import FontFile, Image | |
bdf_slant = { | |
"R": "Roman", | |
"I": "Italic", | |
"O": "Oblique", | |
"RI": "Reverse Italic", | |
"RO": "Reverse Oblique", | |
"OT": "Other", | |
} | |
bdf_spacing = {"P": "Proportional", "M": "Monospaced", "C": "Cell"} | |
def bdf_char( | |
f: BinaryIO, | |
) -> ( | |
tuple[ | |
str, | |
int, | |
tuple[tuple[int, int], tuple[int, int, int, int], tuple[int, int, int, int]], | |
Image.Image, | |
] | |
| None | |
): | |
# skip to STARTCHAR | |
while True: | |
s = f.readline() | |
if not s: | |
return None | |
if s[:9] == b"STARTCHAR": | |
break | |
id = s[9:].strip().decode("ascii") | |
# load symbol properties | |
props = {} | |
while True: | |
s = f.readline() | |
if not s or s[:6] == b"BITMAP": | |
break | |
i = s.find(b" ") | |
props[s[:i].decode("ascii")] = s[i + 1 : -1].decode("ascii") | |
# load bitmap | |
bitmap = bytearray() | |
while True: | |
s = f.readline() | |
if not s or s[:7] == b"ENDCHAR": | |
break | |
bitmap += s[:-1] | |
# The word BBX | |
# followed by the width in x (BBw), height in y (BBh), | |
# and x and y displacement (BBxoff0, BByoff0) | |
# of the lower left corner from the origin of the character. | |
width, height, x_disp, y_disp = (int(p) for p in props["BBX"].split()) | |
# The word DWIDTH | |
# followed by the width in x and y of the character in device pixels. | |
dwx, dwy = (int(p) for p in props["DWIDTH"].split()) | |
bbox = ( | |
(dwx, dwy), | |
(x_disp, -y_disp - height, width + x_disp, -y_disp), | |
(0, 0, width, height), | |
) | |
try: | |
im = Image.frombytes("1", (width, height), bitmap, "hex", "1") | |
except ValueError: | |
# deal with zero-width characters | |
im = Image.new("1", (width, height)) | |
return id, int(props["ENCODING"]), bbox, im | |
class BdfFontFile(FontFile.FontFile): | |
"""Font file plugin for the X11 BDF format.""" | |
def __init__(self, fp: BinaryIO): | |
super().__init__() | |
s = fp.readline() | |
if s[:13] != b"STARTFONT 2.1": | |
msg = "not a valid BDF file" | |
raise SyntaxError(msg) | |
props = {} | |
comments = [] | |
while True: | |
s = fp.readline() | |
if not s or s[:13] == b"ENDPROPERTIES": | |
break | |
i = s.find(b" ") | |
props[s[:i].decode("ascii")] = s[i + 1 : -1].decode("ascii") | |
if s[:i] in [b"COMMENT", b"COPYRIGHT"]: | |
if s.find(b"LogicalFontDescription") < 0: | |
comments.append(s[i + 1 : -1].decode("ascii")) | |
while True: | |
c = bdf_char(fp) | |
if not c: | |
break | |
id, ch, (xy, dst, src), im = c | |
if 0 <= ch < len(self.glyph): | |
self.glyph[ch] = xy, dst, src, im | |