The inverse of SDL_GetModState , SDL_SetModState allows you to impose modifier key states on your application.
Simply pass your desired modifier states into modstate. This value my be a logical OR'd combination of the following:
const
KMOD_NONE = $0000;
KMOD_LSHIFT= $0001;
KMOD_RSHIFT= $0002;
KMOD_LCTRL = $0040;
KMOD_RCTRL = $0080;
KMOD_LALT = $0100;
KMOD_RALT = $0200;
KMOD_LMETA = $0400;
KMOD_RMETA = $0800;
KMOD_NUM = $1000;
KMOD_CAPS = $2000;
KMOD_MODE = $4000;