Source code for PIL.BdfFontFile

#
# 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"}


[docs] 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
[docs] 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