docs/man3/SDL_AddTimer.3
changeset 0 74212992fb08
child 55 55f1f1b3e27d
     1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/docs/man3/SDL_AddTimer.3	Thu Apr 26 16:45:43 2001 +0000
     1.3 @@ -0,0 +1,38 @@
     1.4 +.TH "SDL_AddTimer" "3" "Mon 12 Mar 2001, 01:04" "SDL" "SDL API Reference" 
     1.5 +.SH "NAME"
     1.6 +SDL_AddTimer\- Add a timer which will call a callback after the specified number of milliseconds has elapsed\&.
     1.7 +.SH "SYNOPSIS"
     1.8 +.PP
     1.9 +\fB#include "SDL\&.h"
    1.10 +.sp
    1.11 +\fBSDL_TimerID \fBSDL_AddTimer\fP\fR(\fBUint32 interval, SDL_NewTimerCallback callback, void *param\fR);
    1.12 +.SH "CALLBACK"
    1.13 +.PP
    1.14 +.nf
    1.15 +\f(CW/* type definition for the "new" timer callback function */
    1.16 +typedef Uint32 (*SDL_NewTimerCallback)(Uint32 interval, void *param);\fR
    1.17 +.fi
    1.18 +.PP
    1.19 +.SH "DESCRIPTION"
    1.20 +.PP
    1.21 +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 \fBSDL_AddTimer\fP 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\&.
    1.22 +.PP
    1.23 +To cancel a currently running timer call \fISDL_RemoveTimer\fR with the timer ID returned from \fBSDL_AddTimer\fP\&.
    1.24 +.PP
    1.25 +The timer callback function may run in a different thread than your main program, and so shouldn\&'t call any functions from within itself\&.
    1.26 +.PP
    1.27 +The maximum resolution of this timer is 10 ms, which 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 \fBSDL_INIT_TIMER\fP to \fISDL_Init\fR\&.
    1.28 +.SH "RETURN VALUE"
    1.29 +.PP
    1.30 +Returns an ID value for the added timer or \fBNULL\fR if there was an error\&.
    1.31 +.SH "EXAMPLES"
    1.32 +.PP
    1.33 +.PP
    1.34 +.nf
    1.35 +\f(CWmy_timer_id = SDL_AddTimer((33/10)*10, my_callbackfunc, my_callback_param);\fR
    1.36 +.fi
    1.37 +.PP
    1.38 +.SH "SEE ALSO"
    1.39 +.PP
    1.40 +\fI\fBSDL_RemoveTimer\fP\fR
    1.41 +...\" created by instant / docbook-to-man, Mon 12 Mar 2001, 01:04