Mercurial > sdl-ios-xcode
annotate docs/man3/SDL_AddTimer.3 @ 2866:e532417a6977
Fixed SDL 1.2 compatibility problem.
The API specifies that SDL_OpenAudio() will fill out the 'desired' audio spec
with the correct samples and size set by the driver. This value is important
since it may be used by applications that size audio buffers, etc.
However, we want to allow advanced applications to call SDL_OpenAudioDevice()
which gets passed a const 'desired' parameter, and have the correct data filled
into the 'obtained' parameter, possibly allowing or not allowing format changes.
So... 'obtained' becomes the audio format the user callback is expected to use,
and we add flags to allow the application to specify which format changes are
allowed.
Note: We really need to add a way to query the 'obtained' audio spec.
| author | Sam Lantinga <slouken@libsdl.org> |
|---|---|
| date | Sat, 13 Dec 2008 06:36:47 +0000 |
| parents | 546f7c1eb755 |
| children | 1238da4a7112 |
| rev | line source |
|---|---|
|
181
e5bc29de3f0a
Updated from the SDL Documentation Project
Sam Lantinga <slouken@libsdl.org>
parents:
55
diff
changeset
|
1 .TH "SDL_AddTimer" "3" "Tue 11 Sep 2001, 23:01" "SDL" "SDL API Reference" |
| 0 | 2 .SH "NAME" |
|
2283
546f7c1eb755
Merged revision 3472 from SDL 1.2, fixing bug #493
Sam Lantinga <slouken@libsdl.org>
parents:
181
diff
changeset
|
3 SDL_AddTimer \- Add a timer which will call a callback after the specified number of milliseconds has elapsed\&. |
| 0 | 4 .SH "SYNOPSIS" |
| 5 .PP | |
| 6 \fB#include "SDL\&.h" | |
| 7 .sp | |
| 8 \fBSDL_TimerID \fBSDL_AddTimer\fP\fR(\fBUint32 interval, SDL_NewTimerCallback callback, void *param\fR); | |
| 9 .SH "CALLBACK" | |
| 10 .PP | |
| 11 .nf | |
| 12 \f(CW/* type definition for the "new" timer callback function */ | |
| 13 typedef Uint32 (*SDL_NewTimerCallback)(Uint32 interval, void *param);\fR | |
| 14 .fi | |
| 15 .PP | |
| 16 .SH "DESCRIPTION" | |
| 17 .PP | |
| 18 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\&. | |
| 19 .PP | |
| 20 To cancel a currently running timer call \fISDL_RemoveTimer\fR with the timer ID returned from \fBSDL_AddTimer\fP\&. | |
| 21 .PP | |
|
55
55f1f1b3e27d
Added new docs for SDL 1.2.1
Sam Lantinga <slouken@lokigames.com>
parents:
0
diff
changeset
|
22 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 \fISDL_PushEvent\fR, however\&. |
| 0 | 23 .PP |
|
55
55f1f1b3e27d
Added new docs for SDL 1.2.1
Sam Lantinga <slouken@lokigames.com>
parents:
0
diff
changeset
|
24 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 \fBSDL_INIT_TIMER\fP to \fISDL_Init\fR\&. |
| 0 | 25 .SH "RETURN VALUE" |
| 26 .PP | |
| 27 Returns an ID value for the added timer or \fBNULL\fR if there was an error\&. | |
| 28 .SH "EXAMPLES" | |
| 29 .PP | |
| 30 .PP | |
| 31 .nf | |
| 32 \f(CWmy_timer_id = SDL_AddTimer((33/10)*10, my_callbackfunc, my_callback_param);\fR | |
| 33 .fi | |
| 34 .PP | |
| 35 .SH "SEE ALSO" | |
| 36 .PP | |
|
55
55f1f1b3e27d
Added new docs for SDL 1.2.1
Sam Lantinga <slouken@lokigames.com>
parents:
0
diff
changeset
|
37 \fI\fBSDL_RemoveTimer\fP\fR, \fI\fBSDL_PushEvent\fP\fR |
|
181
e5bc29de3f0a
Updated from the SDL Documentation Project
Sam Lantinga <slouken@libsdl.org>
parents:
55
diff
changeset
|
38 ...\" created by instant / docbook-to-man, Tue 11 Sep 2001, 23:01 |