def get_pango_font_hb_face(pango_font):
    """Get Harfbuzz face out of given Pango font."""
    fc_font = ffi.cast('PangoFcFont *', pango_font)
    fontmap = ffi.cast('PangoFcFontMap *', pango.pango_font_get_font_map(pango_font))
    return pangoft2.pango_fc_font_map_get_hb_face(fontmap, fc_font)
Get Harfbuzz face out of given Pango font.
weasyprint/text/fonts.py