Use fontforge to center the asterisk in a font

asterisk.py

import fontforge

def center(c):
    return (c.boundingBox()[1] + c.boundingBox()[3]) / 2

def transform(input, output):
    font = fontforge.open(input)
    plus = font["plus"]
    asterisk = font["asterisk"]
    asterisk_shift = center(plus) - center(asterisk)
    asterisk.transform((1, 0, 0, 1, 0, asterisk_shift))
    font.generate(output)
    font.close()

if __name__ == "__main__":
    import os
    import sys

    input_dir = sys.argv[1]
    output_dir = sys.argv[2]

    if not os.path.exists(output_dir):
        os.mkdir(output_dir)
    for name in os.listdir(input_dir):
        input = os.path.join(input_dir, name)
        output = os.path.join(output_dir, name)
        transform(input, output)
        print(f"Generated {output}")