Convert PCF and BDF files to bitmap only OpenType (.otb) using fontforge

!README: opentype-bitmap.pe and opentype-bitmap.py

Convert PCF and BDF files to bitmap only OpenType (.otb) using fontforge

If you have a new enough fontforge, the python version of this script can
optionally read filenames from standard input, generating multiple .otb
font files as it finds new families.  It also handles gzipped PCF and BDF
files.

opentype-bitmap.pe

#!/usr/bin/fontforge -quiet
# ./opentype-bitmap.pe - create opentype bitmap from pcf/bdf files

# The .pe in the script name matters, without it fontforge will use python.

if($argc == 1)
    Error("usage: opentype-bitmap.pe size1.pcf [size2.pcf ...]")
endif

New()

i = 1
while(i < $argc)
    Import($argv[i])
    i++
endloop

Generate($fullname + ".otb", "otb")
Print($fullname + ".otb")
Close()

opentype-bitmap.py

#!/usr/bin/env python3
# opentype-bitmap - generate opentype bitmap (.otb) from BDF/PCF fonts

# NOTE
# Greater than version 20190413 is needed.  Otherwise ensure your fontforge
# has commit 79f9e0b8442631ac39ab907af20b813ac584298f

import argparse
import fontforge
import gzip
import os.path
import sys

from tempfile import NamedTemporaryFile


def import_bitmap(font, filename):
    if filename.endswith('.pcf.gz') or filename.endswith('.bdf.gz'):
        ext = filename[-7:-3]  # .pcf or .bdf

        with gzip.open(filename) as gz, NamedTemporaryFile(suffix=ext) as temp:
            temp.write(gz.read())
            font.importBitmaps(temp.name)

    elif filename.endswith('.pcf') or filename.endswith('.bdf'):
        font.importBitmaps(filename)

    else:
        raise ValueError('Unknown extension')


def generate(fontname, files):
    filename = fontname + '.otb'
    newfont = fontforge.font()

    for file in files:
        if args.verbose:
            print(f'{filename}: {file}: importing bitmap strikes',
                  file=sys.stderr)

        try:
            import_bitmap(newfont, file)

        except ValueError:
            print(f'opentype-bitmap: warning: {file}: file must end with '
                  '.pcf.gz, bdf.gz, .pcf, or .bdf', file=sys.stderr)

        except OSError:
            print(f'opentype-bitmap: warning: {file}: invalid bitmap font',
                  file=sys.stderr)

    if newfont.changed:
        newfont.generate(filename, 'otb')
        print(f'{filename}')


parser = argparse.ArgumentParser(add_help=False)
parser.add_argument('-v', dest='verbose', action='store_true')
parser.add_argument('files', nargs='*')
args = parser.parse_args()

if not args.files:
    args.files = (line.rstrip('\n') for line in sys.stdin)

fontfiles = {}

for file in args.files:
    if os.path.isfile(file):

        # Opening the file here to extract the fontname.  There may be a better
        # way to do this.

        # fontforge.open doesn't provide __enter__ and __exit__ attributes.
        f = fontforge.open(file)

        fontfiles.setdefault(f.fontname, []).append(file)
        f.close()

    else:
        print(f'opentype-bitmap: warning: {line}: no such file',
              file=sys.stderr)

for fontname in fontfiles:
    generate(fontname, fontfiles[fontname])