I have a GUI in a game I'm developing. I have two text input boxes. I can input text into it using SDL_KEYDOWN events but how would I go about translating the modifier keys like shift and caps lock to turn letters into capitals and numbers into symbols? I'm looking for something locale-independent. I can just check for the 'shift' key modifier and then apply it manually to whichever key was pressed but like, I would do '!' for '1', but not everyone is using an U.S. keyboard layout.
Does SDL have something built-in for this? If not, is there a cross-platform library for it? Or am I stuck calling OS-specific functions?