Sorry if this is a silly idea, but I thought it might be simpler for some cases than converting the font data to JSON. How about loading the font as a spritesheet? With fixed width fonts (for example pixel fonts) all you'd need is a text string with the order of characters like "abcdefghijklmnopqrstuvwxyz0123456789,.!?;:'()-+" to act as a lookup table, and of course you'd need a custom function to convert any string of text into a block of graphics on the screen. Again apologies if this only makes sense to myself