unicode points above 0xffff are truncated

[vampirefrog]

Hello. Because you are using String.fromCharCode(), any Unicode code points above 0xffff are unusable. It is recommended to use String.fromCodePoint(). Please check out https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/fromCharCode#Getting_it_to_work_with_higher_values

Thanks for a great tool! I am using it to convert bitmap fonts extracted from an emulation ROM (The Sharp X68000 fonts). I use a php script to extract bitmaps, and potrace and svgo to genenerate the svg files, and then glyphs2font to generate the final font. Works great if I do the modification above!