What should I use to handle input? I am wanting to use OpenGL so that my games are cross platform. DirectX provides input libraries, and OpenGL does not. Because my games need to be cross platform, I cannot use DirectX's libraries. What should I do, or what is the common solution to this type of problem?
DirectInput is quite deprecated, as far as I know, and very rarely used. If you're using OGL directly and not through any abstraction, then you will have to go to the operating system API to collect input, or use an abstracting library that has already done this work like SDL, SFML and more.