https://www.libsdl.org/projects/SDL_ttf/docs/SDL_ttf.html#SEC15
I assume the latter is a texture you render into.
https://stackoverflow.com/questions/46044034/are-there-any-penalties-when-allocating-sdl-target-textures-that-are-never-used/46077923
https://wiki.libsdl.org/SDL_RWFromConstMem