Enumerate all characters in font about fontdue HOT 2 CLOSED

    let character_ranges_to_include = vec![
        (32, 128),
        //(0x4e00, 0x5FCC) // large range of CJK characters for testing
    ];

    let mut characters_to_include = vec![];

    use ttf_parser::{Face, GlyphId, TableName};
    let face = Face::from_slice(font_data, 0).unwrap();

    for subtable in face.character_mapping_subtables() {
        subtable.codepoints(|codepoint| {
            for range in &character_ranges_to_include {
                if codepoint >= range.0 && codepoint <= range.1 {
                    if let Some(glyph_id) = subtable.glyph_index(codepoint) {
                        //let name = face.glyph_name(glyph_id);
                        //println!("glyph codepoint: {} {:?} id: {:?} name: {:?}", codepoint, std::char::from_u32(codepoint), glyph_id, name);

                        characters_to_include.push(std::char::from_u32(codepoint).unwrap());
                    }
                }
            }
        });
    }