/* type definition for the "new" timer callback function */ +typedef Uint32 (*SDL_NewTimerCallback)(Uint32 interval, void *param);
Adds a callback function to be run after the specified number of +milliseconds has elapsed. The callback function is passed the current +timer interval and the user supplied parameter from the +SDL_AddTimer call and returns the next timer +interval. If the returned value from the callback is the same as the one +passed in, the periodic alarm continues, otherwise a new alarm is +scheduled.
To cancel a currently running timer call +SDL_RemoveTimer with the +timer ID returned from +SDL_AddTimer.
The timer callback function may run in a different thread than your +main program, and so shouldn't call any functions from within itself. +You may always call SDL_PushEvent, however.
The granularity of the timer is platform-dependent, but you should count +on it being at least 10 ms as this is the most common number. +This means that if +you request a 16 ms timer, your callback will run approximately 20 ms +later on an unloaded system. If you wanted to set a flag signaling +a frame update at 30 frames per second (every 33 ms), you might set a +timer for 30 ms (see example below). + +If you use this function, you need to pass SDL_INIT_TIMER +to SDL_Init.