I’ve been searching to see if a tool like this exists, so figured I’d just ask.
My game has a finite set of strings, so I don’t need every character in a font. I estimate only shipping the actual characters my game needs can save about 100 bytes of flash.
If no tool for this exists, I plan to make one. You give it as input the strings that are in your game, like “new game”, “game over”, etc for example, and the output is a progmem array of the characters you need, the strings encoded such that they can be directly printed from the characters, and a function to do the printing (probably relying on a drawBitmap function to do the real drawing) So basically strings but instead of ascii encoding, a custom encoding based on what characters you actually use. Then if you ever change your strings, just run the tool again.