Using fontforge to generate iconic font

make_font.py

# This is most important parts, not full script
import fontforge
import os
from dataclasses import dataclass

@dataclass
class CharDef:
    # icon name
    name: str
    # path to svg relative to base_dir
    path: str | None = None
    # unicode code point
    code: int = 0

# ...

base_dir = "" # base directory
font_path = os.path.join(base_dir, font_dir, options['font_name'] + '.ttf')
# font_em - size of em in points (we have 1024)
# font_design_size - size of svgs (for ex 24)
design_px = options['font_em'] / options['font_design_size']

font = fontforge.font()
font.encoding = 'UnicodeFull'
# design size in pica points
font.design_size = options['font_design_size']
font.em = options['font_em']
font.ascent = options['font_ascent'] # for icons = 1024
font.descent = options['font_descent'] # for icons = 0
font.fontname = options['font_name']
font.familyname = options['font_name']
font.fullname = options['font_name']
font.copyright = options['copyright']

# Add valid space glyph to avoid "unknown character" box on IE11
glyph = font.createChar(32)
glyph.width = 200

def createGlyph(name, char_def):
    code = char_def.code
    source = char_def.path
    full_source_path = os.path.join(base_dir, source)
    frag, ext = os.path.splitext(full_source_path)

    if ext == '.svg':
        glyph = font.createChar(code, name)

        glyph.importOutlines(full_source_path)
        glyph.width = options['font_em']
        width = glyph.width - glyph.left_side_bearing - glyph.right_side_bearing
        aligned_to_pixel_grid = (width % design_px == 0)
        if (aligned_to_pixel_grid):
            shift = glyph.left_side_bearing % design_px
            glyph.left_side_bearing = glyph.left_side_bearing - shift
            glyph.right_side_bearing = glyph.right_side_bearing + shift

# all_our_chars is a list of CharDef objects
for name in all_our_chars:
    createGlyph(name, chars[name])

# font_path - path to ttf file
font.generate(font_path)