SDL_GetAppState - Get the state of the application
#include "SDL.h"
Uint8 SDL_GetAppState(void);
This function returns the current state of the application. The value
returned is a bitwise combination of:
SDL_APPMOUSEFOCUS The application has mouse focus.
SDL_APPINPUTFOCUS The application has keyboard focus
SDL_APPACTIVE The application is visible
SDL_ActiveEvent